Download Hi-Res ImageDownload to MS-PowerPointCite This:Chem. Rev. 2016, 116, 9, 5464-5519

Noncovalent Functionalization of Graphene and Graphene Oxide for Energy Materials, Biosensing, Catalytic, and Biomedical Applications

View Author Information

† Material Science Department, University of Patras, 26504 Rio Patras, Greece

‡ Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea

§ Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 Listopadu 1192/12, 771 46 Olomouc, Czech Republic

*Tel.: +82-52-217-5410. Fax: +82-52-217-5419. E-mail: [email protected]

*Tel.: +420-58-563-4337. Fax: +420-58-563-4761. E-mail: [email protected]

Cite this: Chem. Rev. 2016, 116, 9, 5464–5519

Publication Date (Web):March 30, 2016

https://doi.org/10.1021/acs.chemrev.5b00620

Request reuse permissions

Article Views

83616

Altmetric

Citations

1901

LEARN ABOUT THESE METRICS

Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.

Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.

The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.

PDF (47 MB)

Get e-Alerts

SUBJECTS:

Get e-Alerts

Abstract

This Review focuses on noncovalent functionalization of graphene and graphene oxide with various species involving biomolecules, polymers, drugs, metals and metal oxide-based nanoparticles, quantum dots, magnetic nanostructures, other carbon allotropes (fullerenes, nanodiamonds, and carbon nanotubes), and graphene analogues (MoS₂, WS₂). A brief description of π–π interactions, van der Waals forces, ionic interactions, and hydrogen bonding allowing noncovalent modification of graphene and graphene oxide is first given. The main part of this Review is devoted to tailored functionalization for applications in drug delivery, energy materials, solar cells, water splitting, biosensing, bioimaging, environmental, catalytic, photocatalytic, and biomedical technologies. A significant part of this Review explores the possibilities of graphene/graphene oxide-based 3D superstructures and their use in lithium-ion batteries. This Review ends with a look at challenges and future prospects of noncovalently modified graphene and graphene oxide.

SPECIAL ISSUE

This article is part of the Noncovalent Interactions special issue.

1 Introduction

ARTICLE SECTIONS

Jump To

Graphene, a recent addition to carbon allotropes, is set to surpass all other allotropes in utility for life and material sciences due to its many intrinsic properties. (1-3) Its abundance in the multilayered form known as graphite can be traced back to antiquity. However, graphite in the form of individual sheets was not technically considered until more recently. It was known in metal workings as Kish and later identified as graphite with impurities existing between the layers. (4) The structure of graphite was deciphered with the advent of single-crystal X-ray crystallography, which revealed the honeycomb nature of individual layers as shown in Figure 1. The single layer called “graphene” is considered as the first two-dimensional (2D) crystal. (5)

Figure 1. A layer of graphene peeled away from the graphite found in a common pencil.

With an early elucidation by Wallace, (6) who took to assuming conduction in the layer and not between van der Waals spaced interlayers, it was then envisioned as a 2D material. Later, individual layers were experimentally observed by Boehm et al. from the reduction of graphite oxide, and they showed that the as-formed porous materials have applications such as in the sorption of gases and small organic molecules. (7, 8) Interestingly, Hoffman and Frenzel (9) described the reduction of graphite oxide using hydrogen sulfide before the demonstration by Boehm et al. (7, 8) that graphite oxide can be exfoliated. These methods of production for single or few layer graphene materials, albeit defective, are still applicable for large-scale production. The ability to make high-quality single layer graphene is credited to Novoselov and Geim who used Scotch tape to pull apart individual layers. (1) This breakthrough made it possible to observe properties that previously were known only in theory. Prior to this mechanical exfoliation, Van Bommel et al. (10) came to the conclusion that a monocrystalline graphite layer is formed over the Si surface, by studying the transformation on the faces of SiC after heating. A model depicting their observations is shown in Figure 2. Upon heating, the silicon is evaporated, allowing the upper carbon atoms to reposition in the next lower layer, and upon longer thermal annealing these atomic carbon layers turn into graphite. (10) A similar phenomenon was noted earlier by Foster et al. (11) during the thermal treatment of Al₄C₃ to grow graphite crystals. (11) Scanning tunneling microscopy images of single layer graphene were presented in 1992 by Land et al. (12) who decomposed either ethylene or naphthalene on a Pt(111) surface. Forbeaux et al. (13) in their 1998 article also used the word graphene to describe the top layer of carbon formed during the growth of graphitic layers on SiC.

Figure 2. Model of the SiC structure in which three carbon layers of SiC are collapsed under evaporation of Si to form one graphite layer: (− – −) unit mesh of SiC (0001); (- - -) unit mesh of the graphite layer; (○) C atoms from the collapse of three carbon layers of SiC; and (●) C atoms of the monocrystalline graphite top layer. Reprinted with permission from ref 10. Copyright 1975 Elsevier B.V.

When the atoms of carbon participate in robust covalent bonds between sp² hybridized states forming an extended honeycomb topology, it gives the structure formed a strength to weight ratio that remarkably outperforms metals and metal composites. (3) Even with such strength, it is relatively flexible and thus can form the different allotropes such as carbon nanotubes, nanohorns, and fullerenes. (14-19) Furthermore, the zero band gap of graphene gives it excellent electron mobility; the investigation and modification of this mobility is important as a means to replace current semiconductors in electronic devices. (20, 21) Such changes can come about by altering graphenes structural dimensions. (22-25) Ideally, a few C atoms thick electronic devices could make such devices nearly invisible, as a single sheet of graphene is ∼97.7% transparent to white light, and represents a new means of delivering information. (26)

Prior to the focus on graphene (G), there was extensive research on the preparations and properties of graphite oxide and later graphene oxide (GO). (27-31) The obvious difference between G and GO is the addition of oxygen atoms bound with the carbon scaffold as shown in Figure 3. As a result, G is hydrophobic in nature whereas GO is hydrophilic, that is, easily dispersible in water. In addition, GO contains both aromatic (sp²) and aliphatic (sp³) domains, which further expands the types of interactions that can occur with the surface. GO is easily reduced to reduced GO at high yields; however, the quality of the produced graphenes is not suitable for electronic applications or mechanical reinforcement of polymers due to structural defects created during the synthesis of GO. Still this is a preferable route for large-scale handling of graphenic materials with tailored surface properties by functionalization.

Figure 3. Oxidation of graphene sheet to form graphene oxide.

Both G and GO described above play a central role in materials science thanks to their unique structural and morphological features, relatively easy chemical modification toward task-specific materials, as well as excellent electrical, mechanical, and thermal properties. Some niche applications include low-cost, large-area, flexible and/or lightweight electronics, displays or e-papers, polymer composites, catalysts, energy-related materials, sensors, and bioderivatives. Particularly the moderate reactivity of G at the interface provides a powerful tool in controlling its structure and properties to meet the applications listed above. Last, G/GO provides an excellent platform for the size-controlled deposition of highly dispersed nanoparticles with catalytic activity.

In most cases, functionalization is the best way to achieve the best performance out of G or GO. In this respect, the literature is massive for the growing applications of G and GO modified through both noncovalent interactions and covalent bonds. Generally, covalent functionalization compromises the sp² structure of G lattices, thus resulting in defects and loss of the electronic properties. In contrast, noncovalent functionalization is largely preferred as it does not alter the structure and electronic properties of G while it simultaneously introduces new chemical groups on the surface. Common examples of noncovalent functionalization include polymer wrapping, π–π interactions, electron donor–acceptor complexes, hydrogen bonding, and van der Waals forces (see examples in Figure 4). In all instances, noncovalent functionalization leads to enhanced dispersibility, biocompatibility, reactivity, binding capacity, or sensing properties.

This Review focuses on noncovalent interactions of G and GO. First, a brief description regarding the nature of noncovalent interactions with G/GO is given in section 2. A detailed survey of various types of interactions and functionalization modes is provided in subsequent sections covering also the interactions of G/GO with polymers, aromatic molecules, biomolecules, drugs, and solvents (section 3). Later, the combination of G/GO with other carbon nanoallotropes and different 2D graphene analogues through noncovalent interactions and 3D superstructures follows (section 4). A significant part of this Review is devoted to the attachment of metal nanoparticles, metal oxide nanoparticles, and semiconducting nanoparticles (quantum dots) onto the surface of G/GO through simple, noninvasive deposition techniques with emphasis on applications in catalysis and lithium-ion batteries. Additionally, specific exploitations of various noncovalently modified G/GO in environmental, biomedical, sensoric, and catalytic applications, as well as in energy materials and nanodevices, are discussed (section 5). This Review ends with a look at current and future prospects of noncovalently modified G/GO (section 6).

Figure 4. Schematic representation of noncovalent interactions of G/GO with selected application-important species involving MoS₂, aromatic polymers, proteins, core–shell nanoparticle, nanotube, quantum dot, ellipticine (drug/photoluminescence probe), DNA segment, and fullerenes (clockwise from top).

2 Noncovalent Interactions of Graphene and Graphene Oxide

ARTICLE SECTIONS

Jump To

Noncovalent or supramolecular interactions are found in all types of materials that experience attractive and/or repulsive forces between them. These interactions are found in many natural and synthetic systems for recognition or detection. (32, 33) For the sake of simplicity, this Review will consider pristine G and avoid defects to the carbon honeycomb scaffold. The allowance of defects or distortions caused by the transformation of sp² carbon to sp³ carbon, in the case of GO, for its involvement with noncovalent interactions is potentially beneficial for combining multiple interactions and will be discussed later.

To compare the relative strength of noncovalent interactions, we consider (i) the energy range of covalent bonds and (ii) the bond distances of single to multiple carbon bonds. The dissociation energies are ∼350 kJ mol^–1 for single, ∼611 kJ mol^–1 for double, and ∼835 kJ mol^–1 for triple bonds, while the bonding distances range from 1.54, 1.34, and 1.20 Å for ethane, ethene, and ethyne, respectively. (34, 35) The energies of individual noncovalent/supramolecular interactions are normally lower than those mentioned for covalent bonds, but when combined over large surfaces they can rival some covalent bonds. The energy ranges for different interactions have been summarized by Atkins and de Pula, (36) Steed and Atwood, (37) and Skinner and Connor. (38) Dissociation energies for ionic bonds range from 100 to 350 kJ mol^–1 and are similar to those of organometallic metal–carbon bonds, which range from 150 to 400 kJ mol^–1. The dissociation energy begins to decrease for noncovalent interactions; that is, ion-dipole or coordinate covalent bonds range from 50 to 200 kJ mol^–1 for coordination complexes or metals bound in crown ethers. These dissociation energies allow noncovalent/supramolecular systems to be reversible, or kinetically labile, and thus self-correcting. With graphenic materials, the π–π or CH−π interactions are prominent with dissociation energies less than 50 kJ mol^–1. The weakest forces, that is, London-dispersion forces or van der Waals interactions, affect all atoms in close proximity. The solvation and hydrophobic effects (caused by different interactions types) are a large component to consider in G and GO systems as they influence not only its dispersibility but recognition interactions that can be used for sensing. (39, 40) The focus on π–π and hydrogen bonds is to target an accessible region at room-temperature conditions, thus making it easier to investigate without specialized laboratory equipment.

Interested readers can find additional detailed information about aromatic interactions in relation to the π–π interactions (i.e., π–π stacking interaction) from the review article by Hunters et al. (41) In G, two types of π–π interactions occur between the electron-rich and electron-poor regions, which influence its interaction with other molecules or nanomaterials. This is commonly seen in the face-to-face and edge-to-face arrangement as shown in Figure 5 for C₆R₆, where R is hydrogen for benzene and other substituents that alter the ring’s polarity. These interactions are not limited to benzene but are also observed in biologically relevant molecules such as DNA and porphyrins. Similarly, these interactions found in small molecules are carried over to GO and G systems where they can be employed to functionalize them for processing and property modification.

Figure 5. π–π stacking face-to-face (left), slipped (middle), and C–H···π (right) type from benzyl molecules where the gray atoms represent carbon and orange represents hydrogen for benzene or other atoms for different derivatives.

The general representation of π–π interaction types observed in G can be seen in Figure 6. Along with this, there is also a small possibility that CH···π-like interactions occur around the edge of G that may be terminated with a hydrogen atom or from phenyl rings oriented perpendicular to the surface of G. Because G is several magnitudes larger than the participating section of the modifying molecule or polymer, there should be multiple interactions on both sides of the G sheet.

Figure 6. Idealized π–π or C–H···π interactions from benzene, naphthalene, or pyrene molecules above and below the basal plane of graphene.

For GO, or more so for reduced graphene oxide (rGO), the basal plane is relatively similar to G except for defects by epoxides or hydroxides bound to the carbon atoms. For this reason, similar π-interactions will likely occur as shown with G, but there are additions of both hydrogen-bond donors and acceptor moieties from the epoxides, alcohols, ethers, carboxylic, and carboxylate oxygen bearing moieties that can contribute an additional mode for interactions. As shown in Figure 7, the oxygen moieties on GO may predominantly situate near or on the edges and aide in binding. Although it is still unclear the qualitative and quantitative distribution of various oxygen bearing functional groups within the basal plane, the reduction of GO can remove many of these groups, leaving an edge dominant oxygen moiety starting material.

Figure 7. Schematic representation of both hydrogen bonds and/or π–π stacking with GO.

Supramolecular interactions with G and the undisturbed regions of GO impart minimum structural impairment, and as such many of the original properties of the starting materials are retained.

The real time visualization of G, or graphite, with molecules adsorbed on the surface via noncovalent interactions, is evident from several scanning tunneling microscopy (STM) studies. Theoretical studies show that molecules on the G surface at either the solid–liquid, solid–atmosphere, or solid–vacuum interface are possible and can manifest as a property modifier for G. (42-44) Foster and Frommer’s first observation of single to several monolayers of 4-n-octyl-4′-cyanobiphenyl onto the surface of highly oriented pyrolytic graphite (HOPG) showed that the ordering lasted for several days during constant scanning (see Figure 8). (45)

Figure 8. Molecules of 4-n-octyl-4′-cyanobiphenyl aligned on the surface of HOPG. Reprinted with permission from ref 45. Copyright 1988 Nature Publishing Group.

Aromatic bodies with aliphatic chains are utilized well for designing 2D crystals on different flat surfaces including G. The favorable π–π interaction allows the molecules to lie flat on the surface while either hydrogen bonding or hydrophobic interaction guides the molecules to form the 2D supramolecular systems. The classic example of hydrogen bonding, leading to 2D supramolecular systems on graphite, is the organization of trimesic acid, which shows the different honeycomb (see Figure 9a) or flower (see Figure 9b) motifs. Griessel et al. (46) showed that the formation of these motifs is due to the formation of carboxylic acid dimer or trimer hydrogen bonds, respectively. This same group also demonstrated the adsorption of coronene, considered the smallest piece of G, on the cleaved surface of HOPG. (47) These two motifs, formed during trimesic acid organization, have been modeled on G and found to influence its electronic properties; this influence is based on the polymorphism. (48) The honeycomb motifs have also been observed in multilayer G by Zhou et al., (49) who also identified a close packing motif (see Figure 9c) on bilayer G supported on SiC. Shortly afterward, the honeycomb arrangement on single layer G was observed by MacLeod et al., (50) and they pointed out that the different supports under the G affect the 2D network. These authors also reported a lack of bandgap opening, using ultraviolet photoelectron spectroscopy, resulting from monolayer adsorption of a trimesic acid network, suggesting a lack of charge transfer. (50)

Figure 9. Scanning tunneling microscopy (STM) images of trimesic acid on the surface of HOPG in (a) honeycomb, (b) flower, and (c) close packing motifs. Panels (a) and (b) reprinted with permission from ref 46. Copyright 2002 Wiley-VCH. Panel (c) reprinted with permission from ref 49. Copyright 2014 Royal Society of Chemistry.

Adding tetrafluoro-tetracyanoquinodimethane (F4-TCQN) to 1–3 layered epitaxial graphene (EG) grown on the 6H-SiC(0001) crystal face was observed using low energy electron diffraction (LEED) along with angle-resolved photoemission spectroscopy (PES). Chen and colleagues demonstrated a p-type doping effect due to electron transfer from EG to the F4-TCNQ adsorbed layer. (51) Interestingly, this layer was not observed on the EG/SiC substrate from STM, but from the STM height data it was considered to stand upright on the surface as shown in Figure 10a. (52) On the other hand, Stradi et al. (53) showed that monolayer coverage of F4-TCNQ or TCNQEG on a Ru(0001) face (see Figure 10b) tailored the magnetic ordering of EG.

Figure 10. (a) Upright arrangement of F4-TCNA on EG/SiC and (b) parallel with the EG/Ru surface. Panel (a) reprinted with permission from ref 52. Copyright 2010 American Physical Society. Panel (b) reprinted with permission from ref 53. Copyright 2014 Royal Society of Chemistry.

Monolayer adsorption of 3,4,9,10-perylene tetracarboxylicdianhydride (PTCDA) arranging in an herringbone motif on bilayer EG/SiC(0001) has been observed (see Figure 11). (54-57) With scanning tunneling spectroscopy (STS), Lauffer et al. (55) observed n-type doping due to charge transfer from PTCDA to EG. In the same way, Huang et al. (54) observed a weak charge transfer from PTCDA to the EG layer using high-resolution PES.

Figure 11. Monolayer of PTCDA adsorbed on EG/SiC(0001). Reprinted with permission from ref 54. Copyright 2009 American Chemical Society.

Similar to PTCDA, perylenetetracarboxylicdiimide (PTCDI) forms monolayers on EG/Rh(111) and EG/SiC(0001). (58, 59) PTCDI monolayers, which adopt a herringbone arrangement, were thermally more stable by around 40 °C than PTCDA on the EG/SiC surface. (59) It was calculated by Kozlov et al. (60) that the bandgap will increase from the physisorption of PTCDI on G. Differences in the 2D arrangement of alkylated and nonalkylated PTCDI on EG/Rh(111) were observed by Pollard and coauthors. The hydrogen-bonding ability between the C═O and N–H in nonalkylated PTCDI allows for linear-like arrangement (see Figure 12a), while the alkylated PTCDI molecules were observed to form hexagonal motifs (see Figure 12b). (58) This type of hydrogen bonding is believed to be one of the reasons behind the stability of the adlayers on EG.

Figure 12. (a) Supramolecular chains of PTCDI and (b) an alkyl PTCDI derivative absorbed on EG/SiC. Reprinted with permission from ref 58. Copyright 2010 Wiley-VCH.

The issue of the interface layer having a profound influence on the G layer was not considered here, but is another challenge for future devices, which needs to be considered. We have briefly shown that many of the aromatic bodied molecules lie parallel with the G basal plane and that there are still challenges to explore in this research area. One of the challenges is to have free floating G, G bridge, or one or both surfaces covered with electron-donating or -withdrawing molecules. Also challenging will be to prepare Janus like G, (61) with two different π–π stacked molecules on either side of G for physical property tailoring. These small molecules that self-assemble onto G and other 2D materials are emerging tools for tailoring the band structure of G.

Before noncovalent interactions can be applied to G, the ability to prepare G dispersed in solution must be considered. A lot of work to make G a viable option for applications has been focused on improving its dispersibility in solvent without altering the honeycomb structure and leaving the material intact. It was revealed by Coleman and others that the surface tension of the solvent should be similar to the surface energy of the material to be exfoliated, that is, a crucial factor for preparing useable quantities of 2D materials. (30, 62-69) It has been found that the surface energy of G of approximately 68 mJ m^–2 is similar to results from contact angle measurements by Wang et al. (70) who reported surface free energies of 54.8 and 46.7 mJ m^–2 for graphite and G, respectively. This value is not necessarily best at explaining the exfoliation for G from graphite, but the Hansen and Hildebrand solubility parameters can shed insight for the dispersion of nanomaterials. (71-73) The Hansen parameters describe the solvent’s mixing ability of dispersive (δ_D), polar (δ_P), and hydrogen-bonding (δ_H) interactions. With G, it was approximated at δ_D,G ≈ 18 MPa^1/2, δ_P,G ≈ 10 MPa^1/2, and δ_H,G ≈ 7 MPa^1/2. (67) These parameters are found for common organic solvents with a low vapor pressure such as NMP and DMF, and also for solvents like isopropanol. (66) This enhancement in our understanding to prepare good dispersions of G or other 2D nanomaterials has a small drawback with the commonly applied sonication procedure. That is, with longer times in the sonication bath, the size is generally reduced, but the quality remains intact.

Alternatively, π–π interactions can be experimentally studied by single molecule force spectroscopy (see Figure 13a). (74, 75) Single molecule force spectroscopy is considered as a poweful experimental tool providing a direct measurement of intermolecular force precisely at a single molecular level; it has been successfully employed to monitor many intramolecular and intermolecular interactions such as covalent bonding, ligand–receptor pairing, host–guest complexation, hydrogen bonding, coordination bonding, hydrophobic interactions, and charge-transfer interactions. For instance, the π–π interactions were directly observed between pyrene and graphite surface in aqueous solutions, manifested by single molecular ruptures (see Figure 13b). (74) The force curve fitting provided determination of the strength of the π–π interactions amounting to ∼55 pN. Another experimental example involves measurement of the force needed to peel the single-stranded DNA from the surface of single crystal graphite; with single molecule force microscopy, it was feasible to identify two types of force–displacement curves, that is, steady-state peeling or polymer chain stretching, depending on the type of the substrate. (75) Effective binding energy for interaction between polythymine and graphite was then estimated to be 11.5 k_BT per nucleotide, in accordance with the theoretically predicted results.

Figure 13. (a) Schematic setup used for measuring the π–π interactions between pyrene and graphite in aqueous medium by single molecule force microscopy. (b) Force curves of pyrene-modified tips desorbed from graphite substrate in aqueous medium under a retraction velocity of 500 nm/s and at room temperature. Reprinted with permission from ref 74. Copyright 2007 American Chemical Society.

3 Driving Forces for Noncovalent Functionalization of Graphene and Graphene Oxide

ARTICLE SECTIONS

Jump To

The noncovalent functionalization of G and GO is mostly based on van der Waals forces or π–π interactions with organic molecules or polymers that meet some basic criteria. Usually, van der Waals forces are developed between G or GO and organic molecules or polymers with high hydrophobic character, while π–π interactions are common between G or GO and molecules with short to highly extended π system. Because of the regular presence of oxygen groups on the surface and edges of GO, ionic interactions and hydrogen bonds are often involved. This is in contrast to pristine G, which has no oxygens that could contribute to these kinds of interactions.

The noncovalent interactions are very important for most applications because the extended π system of graphenic nanostructures is not interrupted, which means that important properties such as electric conductivity or mechanical strength are not affected. In addition, the mild and nonpermanent character of noncovalent interactions offers high flexibility with regards to the treatment of the afforded products. Taking into account that a comprehensive presentation of the noncovalent interactions of graphenic nanostructures has been presented in 2012, that is, our review on G functionalization, (76) this section is focused on the most recent representative research that deals with the noncovalent interactions of graphenic nanostructures with aromatic species, organic molecules, other carbon nanostructures, and inorganic species.

3.1 π–π Interactions

Depending on the basic properties of the aromatic molecules that are concerned, π–π interactions can be involved with the exfoliation of graphite and the stabilization of graphenic nanostructures in dispersion, the use of G as a platform for drug delivery, and the formation of a great variety of hybrids or composite functional materials with advanced properties. On the other hand, basic properties of the organic-aromatic components such as photoluminescence, light absorption, chemical stability, hydrophilicity or hydrophobicity, and morphological and structural characteristics are often influenced by their interactions with G/GO nanostructures.

The π–π interactions have two prevalent requirements. The first is the existence of π systems, and the second has to do with the geometry of the interacting species. It is necessary that an overlap exists between the two components to have a noticeable interaction, and usually this is strongly favored by the planarity of the two components. A pristine G monolayer has a rich extended aromatic system with almost planar geometry, which prefers to interact strongly with small aromatic molecules. On the other hand, rGO has decreased aromatic character, while GO can be described as a nonaromatic surface with sp³ carbon atoms with isolated small aromatic areas, sp² domains. Furthermore, the existence of the sp³ carbon atoms (bonded with oxygen groups) introduces extended deviations from the planarity for GO. These two important factors are intended to differentiate the behavior of GO and rGO from that of G as regards the interaction with aromatic species. On the other hand, the behavior of a G nanostructure is not always similar to all aromatic molecules. The π–π interactions are influenced by several factors related to the aromatic molecules, among them the electron-donating or -withdrawing ability, (77, 78) their substituents, size, and planarity. (79)

Su et al. (78) used pyrene and perylenediimide derivatives to study the π–π interactions between electron donor and acceptor aromatic molecules with graphenic nanosheets. Both aromatic derivatives have been shown to interact strongly with rGO (symbolized as ReG in Figure 14), and the resulting hybrids were highly dispersible in water due to the sulfonic groups that, as part of the aromatic molecules, induce repulsive forces between the hybrid nanostructures. The π–π interactions of an electron donor such as pyrene-1-sulfonic acid (PyS) or an electron acceptor such as 3,4,9,10-perylenetetracarboxylic diimidebisbenzenesulfonic acid (PDI) and rGO are characterized by a remarkable charge-transfer effect that is confirmed by the Raman spectra of the hybrids as a shift of the G-band to lower or to higher frequencies, respectively (see Figure 14).

Figure 14. Aqueous dispersion of (a) rGO, (b) rGO-PDI, and (c) rGO-PyS after centrifugation. (d) G-bands of the Raman spectra of the rGO, rGO-PDI, and rGO-PyS hybrids. Reprinted with permission from ref 78. Copyright 2009 Wiley VCH.

A similar change (upshift and downshift, respectively) was also observed for the C 1s XPS peaks of the hybrids that correspond to sp² carbon in the basal plane of graphenic sheets. The characterization of the hybrids by atomic force microscopy (AFM) revealed planar nanostructures with 1.7 nm thickness that corresponds to a two-phase functionalized graphenic monolayer or 3.4 nm thickness that corresponds to a tandem sandwich structure (see Figure 15). (78)

Figure 15. AFM images and cross-section analysis of (a) rGO/PyS and (b) rGO/PDI on mica. Reprinted with permission from ref 78. Copyright 2009 Wiley VCH.

Using 1-naphthylamine, 1-naphthol, and naphthalene as model aromatic molecules with different polarity, Li et al. (80) showed that polarity is connected to the adsorption ability on a magnetically modified GO. Zhang et al. (81) have presented a detailed study on the ability of different carbon nanostructures to interact with π–π interactions (see Figure 16). They examined the binding ability of GO, rGO (it is characterized as chemically derived graphene, CDG), and single wall carbon nanotubes (SWNTs) using sulfonated aluminum phthalocyanine (AlPcS₄) as the second aromatic planar component.

Figure 16. UV–vis absorption change of AlPcS₄ (15 μm for rGO and 3 μm for GO) by the interaction with increased amount of (a) rGO and (b) GO. Reprinted with permission from ref 81. Copyright 2014 Elsevier B.V.

The π–π interactions of rGO with AlPcS₄ lead to the formation of a ground-state complex between the two components, which is characterized by a remarkable red shift and decrease of the Q absorption band of phthalocyanine as presented in Figure 16. It is also recorded that when the concentration of rGO reaches 12 mg mL^–1, the free AlPcS₄ almost disappears, while a similar concentration of GO (16.2 mg mL^–1) decreased free AlPcS₄ by only 30%. The analogous interaction with respect to SWNTs appeared far weaker. The binding capability as expressed by the formation constant K_s of the complex was estimated to be 21.6 for rGO, 0.31 for GO, and 0.012 g^–1 L for SWNT. It was concluded that the binding ability of carbon nanostructures is analogous to the planarity of the structure, and to bind with the planar AlPcS₄, rGO is by far more favored while the most curved SWNTs are not. The interaction of carbon nanostructures with the excited state was examined by the photoluminescence spectrum of AlPcS₄, in the presence of carbon nanostructures. As presented in Figure 17, the characteristic emission band at 685 nm of AlPcS₄ (15 μM) was decreased by the addition of rGO and totally disappeared when the concentration of rGO reached 12 mg L^–1. The plot of intensity quenching as presented in Figure 17 showed that rGO (it is referred to as graphene in Figure 17) is much more efficient than GO, which means that rGO is also favored as regards the interaction of the excited state of AlPcS₄, with carbon nanostructures, due to the enhanced electron-deficient character in comparison with SWNTs or GO.

Figure 17. (a) PL of AlPcS₄ (15 μM) in the presence of rGO with excitation at 610 nm. (b) The plot of the intensity of quenching with the concentration of rGO, GO, and SWNTs. Reprinted with permission from ref 81. Copyright 2014 Elsevier B.V.

The adsorption capability of GO and rGO has been also studied by Chen et al. (80) using three simple aromatic hydrocarbons, naphthalene, phenathrene, and pyrene, to compare their affinity to GO and rGO. The authors showed that hydrophobic character and the molecular size of the graphenic material affect the adsorption capability, as GO has far less adsorption capability than rGO.

Although pristine G was not a subject of the work by Zhang et al. (81) or Chen et al. (82) presented in the previous section, it can be easily concluded that G would be much more favored with π–π interactions than rGO or GO. G has a much more extended aromatic system and planarity, which means that the free surface that is offered to the aromatic molecules is much larger and so the interactions are stronger. Because of these advantages, π–π interactions of G with small aromatic molecules such as pyridine and fluorinated benzene derivatives, (83, 84) quinoline, (85) pyrene, (86-93) anthracene, (94, 95) triphenylene, (96) coronene, (97) ionic liquids, (98-102) and polymer ionic liquids (103) or porphyrin derivatives (104) can cause the exfoliation of graphite and/or stabilization of the afforded G nanosheets in organic solvents or water. In other words, π–π interactions can be the driving force for the exfoliation of graphite and stabilization of G derivatives in dispersion. The aromatic molecules act as wedges and penetrate slowly between the graphenic layers usually by the assistant of sonication. By this method, the graphenic layers are gradually dissociated from each other, leading finally to a complete separation. The aromatic core of these molecules is usually decorated by hydrophilic or lipophilic chains or groups providing, and through this the liberated graphenic layers are stabilized in water or organic solvents, respectively. Pynidinium tribromide is, among others, a characteristic aromatic molecule that exfoliates graphite and stabilizes graphenic monolayers or multilayers in water thanks to the electrostatic repulsions between the charged pyridinium species that are attached. (83) Lee et al. (86) used a tetrapyrene derivative (1 in Figure 18) decorated by a oligoetherdendron to exfoliate graphite and stabilize graphenic layers. The tetrapyrene aromatic skeleton interacted with G, while oligoether chains induce a high hydrophilic character to the hybrid. The authors showed also that the same tetrapyrene derivative is unable to disperse SWNTs, indicating that the planarity of the carbon nanostructure is a crucial factor for the formation of an effective π stacking. The π–π interactions are confirmed by the red-shifted absorption band and the quenching of the fluorescence band of pyrene when it interacts with G (product 1-G in Figure 18). (86)

Figure 18. (a) Structure of the tetrapyrene derivative. (b) The resulting hybrid is highly dispersible in water (1.5 mg mL^–1). (c) Schematic representation of exfoliation process. (d) Absorption and (e) emission spectra of 1 and **1-G** in 0.2 wt % (MeOH/H₂O); λ_ex = 340 nm. Reprinted with permission from ref 86. Copyright 2011 Royal Society of Chemistry.

Palermo et al. (92) used a series of sulfonated pyrene derivatives to study graphite exfoliation and G stabilization. The pyrene core is functionalized with one, two, three, or four sulfonic groups, which are electron acceptors, while two of them are also functionalized with two and one hydroxyl groups, which are electron donors as presented in Figure 19. The authors studied the procedure in two steps. The first step was the absorption of the pyrene molecules on graphite surfaces without sonication to avoid changes in the initial free surface. Calculating the amount of the unabsorbed pyrene derivative, it was estimated that their absorption on the graphite surface is inversely proportional to the number of the polar sulfonic groups. The second stage was the exfoliation and dispersion in water of the G/pyrene derivative hybrids. In this stage, the favorite molecule for exfoliation is that which has the highest dipole moment and the most asymmetric functionalization (PS2 in Figure 19). (92)

Figure 19. Four pyrene derivatives with increasing number of sulfonic groups used for the study of graphite exfoliation and G stabilization. Reprinted with permission from ref 92. Copyright 2013 Royal Society of Chemistry.

Imidazolium salts have also been used to interact with rGO monolayers. (98-102) These molecules interact with rGO monolayers by cation−π and π–π interactions, while electrostatic repulsions prevent aggregation between the rGO monolayers. In these studies, the role of these interactions is limited to the stabilization of G derivatives in polar solvents or water, because the oxygen groups of GO strongly favor exfoliation. By derivatization with phenyl vinyl groups, imidazolium ionic liquids that are π stacked on G are then copolymerized with vinyl monomers such as methyl methacrylate leading to a G-based polymer composite with homogeneous dispersion of G sheets and strong interaction between the components. (100)

Geng et al. (104) showed that a negatively charged porphyrin derivative (TPP-SO₃Na in Figure 20) is a better dispersant than a positively charged one (TPP-ammonium in Figure 20). Although both derivatives strongly interacted with rGO, only the negatively charged porphyrin can keep the G sheets in dispersion due to the repulsive forces that developed between the negative charges after the noncovalent functionalization.

Figure 20. Porphyrin derivatives with sulfonate and ammonium groups. Reprinted with permission from ref 104. Copyright 2010 American Chemical Society.

The role of the interaction between the π systems of the G structure and aromatic molecules in the final hybrid is so descisive that in some cases it can induce important changes in the structure of the molecules. For example, the introduction of methylpyridinium groups as substituents to the planar porphyrin causes deviation from planarity because pyridinium groups are aligned almost perpendicular to the porphyrin plane due to steric hindrance (see Figure 21). Xu et al. (105) showed that electrostatic and mainly π–π interactions of this tetrapyridinium porphyrin derivative with G forced pyridinium groups to be aligned in the plane with the porphyrin, resulting in a further increase of the π–π interaction.

Figure 21. Schematic representation of pyridinium-functionalized porphyrin interacting with G by π stacking. Reprinted with permission from ref 105. Copyright 2009 American Chemical Society.

As regards the electronic properties of graphenic structures, Arramel et al. (106) showed that interaction with metallic porphyrins can causes a band gap opening in G, which could be further tuned depending on the metal cation of the porphyrin. For example, π stacking of iron protoporphyrin on G yields a band gap of 0.45 eV, while the zinc analogue gives a smaller band gap of about 0.23 eV.

The π system of organic molecules that interact with graphenic nanostructures is also responsible for the photophysical properties of these compounds, and usually the noncovalent interaction with G nanostructures causes important changes. (107, 108)

Phthalocyanine is a highly active chromophore, and its tetrasulfonated derivative (TSCuPc) is totally soluble in water. As a consequence of its aromaticity, it is easily attached onto G nanosheets by π stacking forming highly hydrophilic hybrids (see Figure 22). (108)

Figure 22. π–π interaction of phthalocyanine TSCuPc with G (GR in the image). Reprinted with permission from ref 108. Copyright 2014 Royal Society of Chemistry.

The effective π–π interaction is revealed by the UV–vis spectrum of the hybrid where the characteristic band of the phthalocyanine dimer is not presented because interactions with G prevent the dimerization of phthalocyanine; additionally the Q-band of the monomer, which normally occurs at 663 nm, has been shifted to 705 nm (see Figure 23). (108)

Figure 23. UV–vis spectra of TSCuPc and the hybrid G/TSCuPc. Reprinted with permission from ref 108. Copyright 2014 Royal Society of Chemistry.

The use of the G/TSCuPc hybrid as an agent for photothermal and photodynamic therapies has been further examined. As presented in Figure 24, the hybrid irradiated at 650 nm in a water solution can raise the temperature of the solution close to 55 °C after 10 min of irradiation. (108)

Figure 24. Time-dependent photothermal curves of G/TSCuPc and TSCuPc solutions. Reprinted with permission from ref 108. Copyright 2014 Royal Society of Chemistry.

In comparison with G, the noncovalent interactions of aromatic chromophores with GO or rGO provide different results. G does not exhibit any photoluminescence activity, and π stacking of aromatic molecules results in the quenching of their fluorescence emission as described above. On the other hand, GO, due to its chemical structure, exhibits a broad fluorescence band with λ_max around 600–700 nm (attributed to π–π* transition), and in some cases a second more intense band has been recorded near 450 nm (attributed to n−π* transition). The quantum yield of the photoluminescence of GO is generally small, and during reduction to rGO it is further lowered while the fluorescence bands are tuned to shorter wavelengths. (109-111)

The π–π interactions of rGO with chromophores seem to enhance the fluorescence emission of rGO, while, at the same time, quenching the fluorescence band of the chromophore. A characteristic example of this behavior is recorded by examining the interaction of riboflavin with rGO. Riboflavin (Rb) (vitamin B12) is an amphiphilic organic molecule that consists of a hydrophilic hydroxylated aliphatic chain and a hydrophobic aromatic isoalloxazine part that causes the effective π stacking of Rb on rGO. By excitation at 375 nm, the rGO/Rb hybrid showed a strong emission band at 430 nm remarkably more intense than that of rGO in the same region, while the fluorescence band of Rb, which normally appears near 530 nm, is almost quenched (see Figure 25). (112)

Figure 25. PL spectra of the rGO/Rb hybrid and rGO. Reprinted with permission from ref 112. Copyright 2013 Elsevier B.V.

3.2 van der Waals, Ionic Interactions, and Hydrogen Bonding

Apart from the aromaticity that is involved in the π–π interactions, G is also characterized by its hydrophobic character, which promotes interactions of G with hydrophobic or partially hydrophobic organic molecules such as surfactants, ionic liquids, or macromolecules. These interactions are mostly used for the dispersion of G nanosheets in both aqueous and organic media or their incorporation in polymers. These hydrophobic interactions are also found in rGO, which is closer to G as regards aromatic character and hydrophobicity than GO, which has only a few aromatic regions on its surface and is hydrophilic. GO and, to a lesser degree, rGO also have a number of ionic groups, that is, mainly carboxylate and hydroxylate, which can take part in ionic interactions or hydrogen bonds with the analogous ionic parts of molecules or macromolecules.

The hydrophobic interaction of G or rGO with the aliphatic part of surfactants is often used to achieve an enhanced stability of G or rGO in water. The hydrophilic part of the surfactant responsible for this interaction could be an ionic, zwitterionic, or highly polar group. (113) Cellulose derivatives, (114-116) lignin, (114) albumin, (114) sodium cholate, (117) and sodium dodecyl benzenesulfonate (118) are just some of the amphiphilic organic molecules and macromolecules that have been used successfully as G dispersants and stabilizers. (119) Bourlinos et al. (114) have shown the stable dispersion of pristine G nanosheets with albumin or sodium carboxymethyl cellulose in water. Using liquid exfoliation technique, Lotya et al. (117) have achieved the stable dispersion of 0.3 mg mL^–1 of pristine G nanosheets, with an average thickness of 4 layers, in water using sodium cholate as surfactant.

Stable aqueous suspensions of rGO have also been produced by the assistance of several lignin and cellulose derivatives. Sodium lignosulfonate (SLS) is an amphiphilic polymer, which is attached on rGO by both hydrophobic and π–π interactions due to the coexistence in the macromolecule of aromatic and aliphatic parts. The sulfonic groups of this polymer are responsible for the dispersion of the composite in water. Similarly, sodium carboxymethyl cellulose, a natural polysaccharide, can be attached to G, and stable water dispersions are formed. It should be noted here that π–π stacking is not involved because cellulose is totally aliphatic. Finally, hydroxypropyl cellulose is able to disperse rGO, but the resulting composite is not stable in water unless the cellulose is primarily functionalized with pyrene groups. In this case, the polysaccharide is better attached onto the G surfaces thanks to enhanced π–π interactions, and the resulting composite is stable in water. (120)

On the other hand, when an amphiphilic molecule is attached to the graphenic surface by ionic interactions, the hydrophobic part enhances the stability of G in organic solvents. A representative example is the work of Liang et al. (115) who showed that GO and rGO can be functionalized with quaternary ammonium salts such as tetradecyl-trimethylammonium bromide. The positive “heads” of the surfactants interact with carboxylate and hydroxylate groups on GO or rGO through electrostatic interactions, while the aliphatic chains of the surfactants provide G with the necessary lipophilicity and stability in organic solvents. (115)

Ionic interactions also occur between end functionalized polymers, such as amine terminated polystyrene, and rGO, which lead to the transformation of the hydrophilic rGO into a lipophilic rGO/polymer composite dispersible in organic solvents (see Figure 26). (121)

Figure 26. Transformation of the hydrophilic rGO to an organophilic rGO/polymer composite using an amine terminated polystyrene. Reprinted with permission from ref 121. Copyright 2010 Royal Society of Chemistry.

4 Noncovalently Functionalizing Agents of Graphene and Graphene Oxide

ARTICLE SECTIONS

Jump To

4.1 Functionalization with Polymers

G derivatives usually have excellent mechanical, thermal, and electrical properties. A simple way to utilize these properties is their incorporation in polymer composites. A key factor for the ideal incorporation of graphenic nanostructures into polymer matrixes is the covalent or noncovalent interactions, which determine the homogeneity of the composite and the extent of the cooperation between the two components. The existence of π–π interactions between graphenic derivatives and polymers that contain aromatic rings is an excellent example in this case. A repeating aromatic polymer unit can strongly bind graphenic monolayers leading to highly homogeneous polymer composites with enhanced mechanical, electrical, and thermal properties. (122-125) Kevlar is a characteristic polymer with aromatic rings, which can interact strongly with G by π stacking as presented in Figure 27. Lian et al. (122) have used a Kevlar/graphene nanoribbon (GNR) composite to reinforce polyvynil chloride (PVC). The afforded Kevlar/GNR/PVC composite (containing 1 wt % GNR) demonstrated an increase of about 72.3% and 106% in Young’s modulus and yield strength, respectively.

Figure 27. Interaction of Kevlar with graphene nanoribbons. Reprinted with permission from ref 122. Copyright 2014 Elsevier B.V.

The sulfonated derivative of polyaniline can also interact with G through π stacking providing a water dispersible composite. (126) Zhang et al. (123) used a series of phenyl or pyrene terminated functionalized polyethylene glycols (f-PEG) to interact with rGO via π stacking (see Figure 28). The pyrene groups were attached onto the G surface, while the flexible ethylene glycol chains allowed interconnection of the nanocomponents, thereby affording a stiff composite with enhanced mechanical properties. The electrical conductivity of these polymer composites is a result of the mixture of a nonconductive component such as the polymer and a conductive part such as G. The authors also studied the role of the aromatic end groups in the electrical conductivity of the final product. As shown in Figure 29, apart from the decrease of the conductivity as the amount of the polymer increased, the aromatic end groups influence the conductivity of the material with the terminal phenyl group giving the most favored conductivity. (123)

Figure 28. (a) Synthetic procedure of adding aromatic end groups to polyethylene glycol and (b) schematic presentation of the f-PEG/rGO composite formation. Reprinted with permission from ref 123. Copyright 2015 Elsevier B.V.

Figure 29. Electrical conductivity of the PEG/rGO composites with different polymer loadings. Reprinted with permission from ref 123. Copyright 2015 Elsevier B.V.

Polymers without an aromatic part have been also reinforced with G or rGO nanosheets. For example, cetyltrimethylammonium bromide surfactant (CTAB) has been used to disperse GO or rGO into natural rubber providing a polymer composite with improved electrical, chemical, and mechanical properties. (127) Surfactant-assisted mixing has been also used to disperse surfactant functionalized rGO into water-soluble polyurethane (WPU, polyurethane functionalized by sulfonate groups). The ionic interaction between the sulfonate group of WPU and the tertiary amine group of the surfactant is the driving force for the homogeneous dispersion (see Figure 30). (128)

Figure 30. Preparation of a composite material with waterborn polyurethane and surfactant covered rGO. Reprinted with permission from ref 128. Copyright 2013 Elsevier B.V.

4.2 Functionalization with Biomolecules

In a manner similar to polymer composites, G and rGO have been combined successfully with biomolecules. For example, heparin is a biomolecule, which consists of a relatively hydrophobic cellulose backbone that is covered by a dense hydrophilic net of negatively charged carboxylates and sulfonate groups. The interaction of rGO and heparin is favored by the hydrophobic character of the heparin backbone and the rGO surface, while the repulsive forces between the charged surfaces of the composite keep it stable in aqueous biological media dispersion. (129) Hydrophobic interactions are also responsible for the immobilization of horseradish peroxidase on rGO. (130) When GO is used instead of rGO, the immobilization of enzymes such as horseradish peroxidase and lysozyme is dominated by strong electrostatic and hydrogen-bond interactions between oxygen groups of the GO and nitrogen groups of the enzymes (see Figure 31). (131)

Figure 31. Tapping mode AFM images of horseradish peroxidase (HRP) immobilized on GO at (a) small and (b) large enzyme loadings. (c) Schematic model of the GO-bound HRP. (d) Initial reaction rates of GO-bound HRP versus HRP concentration. Reprinted with permission from ref 131. Copyright 2010 American Chemical Society.

On the other hand, biomolecules with aromatic parts can interact with G through π–π interactions. A characteristic case is the immobilization of glucose oxidase on G. (132) Dopamine is a biological substance with remarkable contributions in the central nervous, renal, and hormonal systems, it acts as a neurotransmitter, and thus its detection and quantitative determination is very important for human health. (133) Usually, its presence is accompanied by the presence of ascorbic acid in much higher concentrations that cause interferences in the detection of dopamine. Electroanalysis has been used to establish effective methods for the determination of biological molecules with electrochemical activity, such as dopamine and ascorbic acid. The role of G here is very important because it has been shown that electrodes covered with G can discriminate between the presence of dopamine from that of ascorbic acid-based, due to the selective π–π interactions of dopamine with the graphenic surface. In this way, G modified electrodes can be used as selective sensors of dopamine in the presence of ascorbic acid that does not interact with the G surface. (134, 135) The linear range of these electrodes varies from 5–200 μm, (134, 135) and a detection limit of close to 2.64 μm has been reported. (134) G has been further modified to achieve better analytical results with regards to the determination of dopamine in the presence of other biological molecules. (136-140) The role of π–π interactions in these materials is also decisive. As shown in Figure 32, tryptophane can be attached by π stacking onto the G surface, and then this composite material is used to modify the electrode surface. (136) In this way, the linearity for the determination of dopamine ranges between 0.5 and 110 μm, and the detection limit is 0.29 μm. (136) Similar results have been achieved for an electrode coated with G modified with 3,4,9,10-perylenetetracarboxylic acid (PTCA). (137)

Figure 32. Deposition of tryptophane/G on a glassy carbon electrode (GCE) for the determination of dopamine. Reprinted with permission from ref 136. Copyright 2014 Elsevier B.V.

In another approach, water-soluble porphyrin and rGO have been examined as an electrochemical detector for the determination of dopamine. The electrode formed in this study displays a detection limit of 9 × 10^–9 M and a linear range between 10^–6 and 7 × 10^–5 M. Importantly, the detection of dopamine was not influenced by the presence of other interfering compounds such as uric and ascorbic acid. (138) Interesting results have also been reported for a hemin modified G electrode. Hemin is an iron-containing protoporphyrin known by its existence in the active site of heme protein. (139)

A great development has been recorded the last years in the area of hybrid nanomaterials based on the interactions of graphenic nanostructures with DNA probes. Single-stranded DNA (ss-DNA) macromolecules are easily immobilized on the surface of graphenic layers through π–π interactions between the hexagonal cells of G or GO and the aromatic bases. (141) Such G or GO/ss-DNA hybrids have been used as biosensors for the detection of DNA sequences that are linked to several diseases and genetic disorders based on the strong interactions that developed between the complementary DNA strands. G or GO/DNA hybrids as biosensors have been presented in detail in several significant review articles. (142-144)

In a characteristic example, Yang et al. showed that the fluorescence quenching of a dye labeled ss-DNA after the interaction with a GO surface was recovered in the presence of the complementary target DNA due to the interaction of complementary DNA strands, as presented in Figure 33. The presence of a noncomplementary ss-DNA has no effect on the situation of the hybrid. (145)

Figure 33. Schematic representation of the target-induced fluorescence change of a dye labeled ssDNA/GO hybrid. FAM is the fluorescein-based fluorescent dye. Reprinted with permission from ref 145. Copyright 2009 Wiley-VCH.

Pumera et al. have also developed G platforms for the detection using as detection techniques the electrochemical impedance spectroscopy (EIS) (146-149) or the redox properties of GO. (150) Here, a very sensitive detection technique such as EIS and hairpin shaped DNA probes, which offer high selectivity, are combined successfully in the detection of immunoglobulin (IgG) and DNA single nucleotide polymorphism, which is correlated to the development of Alzheimer’s disease.

A very simple electrochemical detection of a DNA sequence is described in Figure 34. The surface of three electrodes was covered by ssDNA through π–π interactions and then was exposed to complementary, one-mismatch target, and noncomplementary target DNA, respectively. The three electrodes then are exposed to a suspension of GO nanoplatelets. The electrode with the complementary DNA strands has significantly different behavior due to the interactions of the complementary DNA strands. In fact, the interaction of the complementary DNA strands favors the formation of double strands on the electrode surface, which have much lower conjugation ability with the free GO nanoplatelets in comparison with the electrode exposed to the noncomplementary target that remains covered by single strands. This different behavior in the electrochemical reduction of GO was recorded by cyclic voltammetry. (150)

Figure 34. Electrochemical behavior of GO nanoplatelets after the interaction with ssDNA modified electrodes exposed to (a) complementary, (b) one-mismatch, and (c) noncomplementary targets. Reprinted with permission from ref 150. Copyright 2012 American Chemical Society.

In a different approach as regards their interaction with biomolecules, GO has been presented to work successfully as modulators against protein misfolding and aggregations known as amyloidosis which, are correlated with Alzheimer’s (151) and other similar diseases. (152, 153) GO has been shown to prevent in vitro the amyloid fibril formation in peptide solution thanks to noncovalent interactions between graphenic nanostructures and peptides that overcome peptide interactions. Furthermore, according to recent work, the modulation effect of GO seems to be size dependent with the large GO nanostructures having a better function on Aβ_33–44 aggregation than GO with size of less than 50 nm (see Figure 35). (154)

Figure 35. AFM images showing (a) the formation of fibrils after aggregation in a solution of Aβ_33–44 peptide and (b) the absence of fibrils when in the peptide solution with GO nanoplatelets. Reprinted with permission from ref 154. Copyright 2015 Wiley VCH.

4.3 Functionalization with Drugs

An interesting application of graphenic nanostructures is their utility as platforms for the stabilization and the delivery of organic molecules that are used as drugs in therapeutic protocols. This specific role needs two important requirements from the graphenic nanostructures: a covalent or a noncovalent interaction with the organic molecules and the necessary hydrophilicity that promotes the easy dispersion of the hybrid in water or biological fluids. The hydrophilic character of GO is ensured by its carboxylate and hydroxylate groups, while pristine G or rGO has to be functionalized with hydrophilic groups or polymers before their use as drug delivery platforms. As regards the immobilization of the molecules, noncovalent interactions such as π–π stacking are preferable in most cases (i.e., precondition of the aromatic character of the molecule) because the release of the molecules is much easier to manipulate in comparison with that of covalently bonded molecules on the graphenic surface. Ramisol is an example of an aromatic organic molecule with antimicrobial and antioxidant activity that can be attached to G by π–π stacking. (155) The three carboxylates, present at the ends of the molecule, offer the necessary water solubility for the pristine G nanosheets (see Figure 36). (155)

Figure 36. (a) Molecular structure of Ramisol and the hybrid with a G layer. (b) Dispersion of the hybrid in water with different ratios. Reprinted with permission from ref 155. Copyright 2015 Elsevier B.V.

Hypocrellins are naturally occurring perylenequinonoid pigments that have been intensively studied as photosensitizers in photodynamic therapy. They include two similar molecular structures, hypocrellin A and B, and their major advantage is the very high quantum yield in the production of singlet oxygen. Although hypocrellins are highly active toward many kinds of tumor cells, their use in vivo is almost prohibited by its poor solubility in water. Zhou et al. (156) showed that hypocrellins can be made more water-soluble by interaction with a GO surface mainly by π–π interaction as well as hydrogen bonds between the hydrogen and the oxygen groups of both components (see Figure 37). In vitro experiments showed an effective uptake of GO/HB into the tumor cells and the subsequent damage upon irradiation. (154)

Figure 37. (a) Molecular structure of hypocrellin A and B. (b) Schematic representation of the GO/HB hybrid. Reprinted with permission from ref 156. Copyright 2012 Elsevier B.V.

Water dispersible PEGylated graphene nanoribbons have been also used as platforms for the effective delivery of lucanthone (a thioxanthone-based antitumor drug that targets base excision repair enzyme APE-1 (Apurinic endonuclease-1)) into glioblastoma multiformae (GBM) cells. The aromatic character of lucanthone favors the stabilization of large amounts of the drug on the graphenic platform by π stacking (310 μm onto each mg of G material). (157)

Quercetin is a natural product of the family of bioflavonoids found in fruits and vegetables. It is well-known for its antioxidant and anticancer activity as well as for a broad range of health benefits. Even though quercetin has hydroxyl groups, it has low solubility in water and serious instability in the intestinal fluids. Rahmanian et al. (158) showed that quercetin can be immobilized onto a GO surface by π stacking, and the formed hybrid showed the necessary stability in physiological solutions and no toxicity in vitro.

Enhanced hydrophilic character and biocompatibility can be achieved with GO after its covalent functionalization by PEG chains. The PEGylated GO was then modified with an insoluble aromatic molecule SN38 (a captothesin analogue) with anticancer activity, and water solubility was achieved. (159) The anticancer drug CPT has been also immobilized on pristine G nanosheets functionalized by dihydroxy phenyl groups that induce hydrophilicity. (160) Other drugs that have been attached by π–π stacking on G or GO surfaces are doxorubicin (161) and ellipticine. (162)

Koninti et al. (162) have presented the effective loading of ellipticine (an anticancer drug) on GO and its release to intracellular biomolecules like DNA/RNA. Ellipticine (E) is an aromatic alcaloid that is stable in two forms (i.e., neutral and protonated), intercalates DNA, and acts as topoisomerase II inhibitor (see Figure 38). E is characterized by a strong dual photoluminescence while its λ_max moves between green and blue or dark blue upon interaction of the molecule with GO, proteins, DNA or RNA, and sugar. As presented schematically in Figure 38, when the green emoting protonated E (λ_max = 520 nm) is immobilized on GO in the neutral form by π–π interactions, it is not fully quenched as expected but still emits blue light with λ_max at 450 nm. The interaction of DNA or RNA with the GO/E sample resulted in the return of the green fluorescence emission (λ_max = 520 nm) in the complex showing the progressive release of E from GO surface and its strong interaction with these biomolecules. The addition of serum albumin protein (HSA) in the GO/E sample strengthened the luminescence of the complex, which is not shifted in the presence of DNA, showing that the protein can protect E from unwanted release (see Figure 38). (162)

Figure 38. (a) Neutral and protonated forms of ellipticine. (b) Photoluminescence of E free and after its π–π interaction with GO and changes in the presence of HSA, DNA, RNA, or HSA and DNA. Reprinted with permission from ref 162. Copyright 2014 Royal Society of Chemistry.

4.4 Functionalization toward 3D Superstructures

Noncovalent interactions have been used for a special kind of nanoarchitecture creating superstructures based on G or GO nanosheets. In these structures, several aromatic molecules have been used as bridges, linkers, and spacers between graphenic sheets and other surfaces.

Noncovalent interaction has often been used to promote the use of small aromatic molecules such as pyrene derivatives as linkers for the connection of graphenic layers to other bodies. Chia et al. (163) have presented a pyrene derivative as a linker between G and glucose oxidase in a bioelectrochemical sensor of glucose (see Figure 39).

Figure 39. Pyrene links graphene and glucose oxidase through π–π stacking. Reprinted with permission from ref 163. Copyright 2015 Elsevier B.V.

In a similar approach, pyrene groups can form a bridge between G layers and a gold electrode (see Figure 40). (164, 165)

Figure 40. Pyrene interconnection between G and gold electrode. Reprinted with permission from ref 164. Copyright 2013 Elsevier B.V.

Porphyrin functionalized rGO has also been used as biosensor for glucose in human serum thanks to its excellent electrocatalytic activity toward the reduction of dissolved oxygen. (166) Thanks to their aromatic part, cyclophanes can be entrapped between graphenic layers forming a characteristic host–guest 3D superstructure. The driving force here is the π–π interactions between the aromatic system of cyclophane and that of CBDAP⁴⁺/GO. A cyclophane with diazapyrenium and benzene units (see Figure 41) has been shown to interact effectively with GO nanosheets forming a supramolecular organogel. The position of cyclophane between the two GO nanosheets is suggested by the arising distance of 13.3 Å as estimated by the powder X-ray diffraction analysis of the superstructure. (167)

Figure 41. (a) Structure of a cyclophane with diazapyrenium units (CBDAP⁴⁺), (b) photo of CBDAP⁴⁺/GO gel, and (c) representation of the possible position of cyclophane/CBDAP between GO layers. Reprinted with permission from ref 167. Copyright 2014 Wiley-VCH.

4.5 Functionalization with Carbon Nanoallotropes

Carbon nanotubes have a strong aromatic character that promotes π–π interactions, although their curved shape deteriorates this trend. In general, there is a remarkable noncovalent interaction between carbon nanotubes and G nanostructures that leads to stable superstructures of these carbon hybrids. Several nanoarchitectured aerogels, foams, thin films, membranes, and paper-like sheets constructed by a combination of graphenic nanostructures and carbon nanotubes have been described in a recent review. (168) For example, the presence of dispersed SWNTs in a suspension of GO in water during hydrothermal reduction of the GO to rGO resulted in the formation of an aerogel superstructure after solvent removal by a freeze-drying procedure (see Figure 42). (169)

Figure 42. Schematic representation of aerogel formation toward the rGO/SWNT hybrid. Reprinted with permission from ref 169. Copyright 2015 Elsevier B.V.

Georgakilas et al. has recently developed a hybrid nanostructure by combining hydroxy functionalized multiwalled carbon nanotubes (MWNTs) with pristine G through π–π interactions; the as-formed material exhibited high dispersibility in water and remarkable electrical conductivity (see Figure 43). (170) The hydrophobic G nanosheets are covered by the hydrophilic MWNTs affording a hydrophilic hybrid. Furthermore, the MWNTs act as conductive interconnectors between the G layers, improving the conductivity of the final hybrid. (170)

Figure 43. (a) Formation of G/MWNTs-f-OH hybrid and (b) its dispersion in water. (c) Graphene precipitate without MWNTs-f-OH following the same procedure and (d) the hybrid in ethylene glycol at high concentration. Reprinted with permission from ref 170. Copyright 2015 Wiley-VCH.

Hydrophilic GO has been also used for the creation of stable dispersions of nonpolar pristine carbon nanotubes in water through π–π interactions. (171) The electron acceptor [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) is the most commonly used fullerene derivative in bulk heterojunction polymer solar cells (BHJ-PSC). (172-175) G could be used in combination with PCBM, offering an excellent road for charge transportation during the solar cell function. Yang et al. (176) used a pyrene derivative of PCBM for its better adhesion onto rGO through π–π stacking, although fullerene derivatives could be also stacked onto the G surface (see Figure 44).

Figure 44. Schematic representation of the two possible conformations of the pyrene-PCBM/rGO hybrid: (a) C₆₀ is attached on the graphenic surface simultaneously with the pyrene stacking, and (b) C₆₀ is kept far from G and pyrene. Reprinted with permission from ref 176. Copyright 2013 American Chemical Society.

From the two possible configurations presented, microscopic and spectroscopic data show that the proposed structure is that where C₆₀ is kept far from the G surface and pyrene is the adhesion medium. The use of the hybrid in BHJ solar cell increases the efficiency 15%, while the use of pyrene-PCBM or rGO separately decreases the efficiency. However, as mentioned above, C₆₀ moieties can be grafted on graphenic surfaces by π-stacking without the use of other aromatic linkers. A simple grinding of a mixture of GO and C₆₀ led to the formation of a GO/C₆₀ hybrid, which is stable in water at significant concentrations due to the high hydrophilicity of GO that dominates over the hydrophobic character of C₆₀. The GO/C₆₀ hybrid has been used as substrate for the immobilization of phosphotungstic acid (PTA); this material is then electrodeposited to form a thin film electrode of the PTA/GO/C₆₀ composite. PTA is a highly active redox catalyst; therefore, the use of the PTA/GO/C₆₀ composite showed enhanced catalytic activity toward the electrochemical redox reactions of several organic compounds such as dopamine, ascorbic acid, uric acid, etc. (177)

Recently, a few-layer G/nanodiamond (FLG/NDs) hybrid has been prepared as a carbon-based catalyst for the steam-free dehydrogenation of ethylbenzene to styrene. The enhanced amount of nanodiamonds that are dispersed on FLG surface is promoted by the large number of defects and vacancies of the FLG. The specific surface area of the hybrid is 330 m² g^–1, much larger than that of pure FLG, which is about 30 m² g^–1, because NDs are inserted between the FLG layers and prevent restacking. Acting as catalyst, the hybrid showed 4 times higher dehydrogenation activity as compared to unsupported NDs (see Figure 45). (178)

Figure 45. SEM and TEM micrographs of (a,d) bulk nanodiamonds, (b,e) few-layer graphene (FLG), and (c,f) the FLG/NDs hybrid. Reprinted with permission from ref 178. Copyright 2015 Elsevier B.V.

Finally, π–π and hydrophobic interactions haven been shown to be responsible for the strong attachment on GO of small polyaromatic and oxygenated species, which are coproduced during the oxidative procedure of graphite and usually called oxidative debris. (179) Many researchers have studied the last years the role of the oxidative debris in several properties of the as-prepared GO, revealing a significant contribution such as in water dispersibility, (180) fluorescence, (181) electroactivity, (182) and chemical reactivity. (183) In contrast with the early suggestions about the structure of GO, recent studies have shown that the product of the strong oxidation procedure that was applied on graphite according to the known well-established methods such as Staudenmaier, Hofmann, Hummers, and Tour oxidations consisted mainly of poorly oxidized large G nanosheets and highly oxidized relatively small aromatic species, which are strongly attached on the surface of GO. It is concluded that most of the oxygen functionalities on the product of graphite oxidation are concentrated on these small polyaromatic species. The so-called oxidative debris has a humic- or fulvic-like structure with carboxy, hydroxyl, and epoxy functionalities anchored to the edges. Because of their large number of hydrophilic oxygen groups, they act as surfactant and contribute to the dispersibility of GO in water. Consequently, pure GO nanosheets that arise after removal of debris by ultrasonication are not so poorly dispersible in water and more electrically conductive than before debris removal. (179) In addition, Coluci et al. (183) have shown that pure GO is much more effective in noncovalent interactions.

Pumera et al. (182) showed by using cyclic voltametry that a stepwise decrement in the inherent electroactivity of GO is observed by increasing the ultrasonication time from 2 to 24 h, which is attributed to the analogous removal of oxidative debris, concluding that inherent electroactivity came mostly from the oxidation debris (see Figure 46).

Figure 46. Schematic representation that shows how the removal of oxidative debris is correlated with the reduced electroactivity of GO in cyclic voltametry. Reprinted with permission from ref 182. Copyright 2014 American Chemical Society.

4.6 Functionalization with 2D Graphene Analogues

The tremendous interest in G inspired researchers to develop 2D inorganic monolayers from transition metal oxides and dichalcogenides that have a layered structure. (69, 184, 185) The atomic thin layers are constructed by covalent bonds between transition metals such as Ni, V, W, Mo, Nb, Bi, Ta, and oxygens or nonmetallic elements such as S, Te, and Se. The layers are held together by van der Waals interactions. Although the layered structure and the properties of these inorganic compounds were known several decades ago, it was only recently confirmed that the monolayered structures can be stable. Additionally, these materials exhibit interesting electronic, magnetic, optical, and mechanical properties different from their 3D analogues. For example, bulk molybdenum sulfide (MoS₂) is an indirect band gap semiconductor, while a MoS₂ monolayered structure has a direct band gap and strong photoluminescence. (186) This observation gave the necessary motivation for the development of inorganic 2D materials for potential application in optoelectronics devices, catalysis, photovoltaics, batteries, etc. A recent review on 2D materials has been presented by Gupta et al. (184) where synthetic methods, characterization techniques, properties, and applications are described.

Supporting the similarity with G, 2D inorganic materials can be produced by methods such as mechanical cleavage, (187-189) liquid phase exfoliation (see Figure 47 and Figure 48), (69, 190, 191) chemical vapor deposition (CVD), (192, 193) and molecular beam epitaxy. (194)

Figure 47. (a–c) Low-resolution TEM images of BN, MoS₂, and WS₂ layered flakes. (d–f) High-resolution TEM images of BN, MoS₂, and WS₂ monolayers. The insets show fast Fourier transforms of the images. (g–i) Butterworth-filtered images of sections of the images in panels (d), (e), and (f), respectively. Reprinted with permission from ref 190. Copyright 2011 American Association for the Advancement of Science.

Figure 48. Schematic representation of three similar liquid exfoliation processes based on (a) intercalation, (b) ion exchange, and (c) ultrasonic exfoliation. Reprinted with permission from ref 69. Copyright 2013 American Association for the Advancement of Science.

The next step following the deconstruction of graphite and inorganic layered materials down to G and inorganic monolayers, respectively, was the reorganization of the different monolayers into new 3D or few layered 2D heterostructured hybrids with combined properties. The advantage of this research is that the properties of the final hybrid can be predetermined by a careful selection of the starting components and the way that they are placed in the hybrid. Up to now, the most used methods for the development of layered heterostructures are CVD growth, (195, 196) and the mechanical transfer or deposition of chemically exfoliated 2D crystals layer by layer. (197) One of the simplest ways to make a hybrid heterostructure is illustrated for the G/MoS₂ hybrid material, which is produced by bringing in contact a glass slide with micrometer-sized exfoliated G nanosheets and a Si/SiO₂ substrate decorated by MoS₂ layers mechanically deposited. (198, 199) The G/MoS₂ hybrid combines the electrical properties of G with the optical activity of semiconductor. Interestingly, a persisted photoconductivity in G was induced, which can be reverted back to the dark state by a voltage pulse application; this results in an electrically controlled photoinduced memory device (see Figure 49). (198)

Figure 49. Schematic representation of the device with G and MoS₂. Reprinted with permission from ref 198. Copyright 2013 Elsevier B.V.

On the other hand, the MoS₂/G heterostructure where MoS₂ is covered by a layer of G has been applied for the ultrasensitive detection of DNA hybridization, (200) as a nanobiosensor, (201) and a p–n junction. (202)

Tungsten sulfide (WS₂) has been also deposited as few layered nanosheet supported on rGO through a hydrothermal procedure. The rGO/WS₂ hybrid heterostructure showed enhanced electrochemical and rate capability performance as an anode for lithium-ion batteries (LIBs). The characterization of the hybrid is based on X-ray diffraction patterns and Raman spectra, while the two components were also indicated by TEM micrographs. X-ray diffraction mostly indicates the hexagonal structure of WS₂ monolayer, while the presence of the (002), (100), and (110) reflections are due to the few layered structure of WS₂ (see Figure 50). The decreased crystallinity of the hybrid due to the presence of rGO in the hybrid is also observed. The Raman spectrum of the hybrid showed the characteristic G and D bands of graphene at 1585 and 1350 cm^–1, respectively, and the characteristic band of WS₂ at 350 and 415 cm^–1 due to the E_2g and A₁₂ modes, respectively. (203)

Figure 50. (a) X-ray diffraction patterns and (b) Raman spectra of bare WS₂ and the hybrids WS₂/rGO in two different ratios. Reprinted with permission from ref 203. Copyright 2013 Elsevier B.V.

The layered structure of these materials offers the opportunity to combine more than two different nanostructures in a 3D assembly. Recently, Roy et al. (204) have shown the construction of a field-effect transistor combining G nanosheets with MoS₂ and h-BN monolayers. G has the role of source/drain and the top-gate contacts, h-BN is the top-gate dielectric, and MoS₂ is the active channel material (see Figure 51).

Figure 51. Schematic representation of a field-effect transistor constructed by graphene, MoS₂, and h-BN layers. Reprinted with permission from ref 204. Copyright 2014 American Chemical Society.

4.7 Functionalization with Nanostructures

It is well-known that the use of nanoparticles in various applications depends on a multitude of factors such as size, number of facets, facet order, shape, surface area, etc. (205) These factors are in turn dependent on a vast number of reaction conditions such as temperature, concentration, time, precursors, and many more. Additionally, in many applications, the use of nanoparticles requires immobilization on a substrate surface. In this regard, G and GO can act as a substrate for nanoparticles in many applications where the inherent properties of G, such as conductivity or anchoring sites, could be beneficial. (206, 207)

Depending on the G substrate used, the nanoparticles can either be deposited directly onto the surface or be grown on the surface. For example, it may be easier to grow nanoparticles directly onto the surface when using GO as a substrate, as it has multiple oxygen functionalities where seeding can take place. (208) On the other hand, it may be easier to deposit already grown nanoparticles onto pristine G as it should lack vast numbers of seeding sites. (209) Obviously, these two examples are broad generalizations, but they demonstrate the uniqueness of G as a substrate for nanoparticle deposition.

It should be pointed out here that in many reports the nanoparticle deposition claimed as noncovalent could in fact be covalent bonding occurring between the G surface and the nanoparticle. However, multiple groups have not offered detailed confirmation of either covalent or noncovalent bonding between the G surface and the nanoparticle. As such, we present here materials that have been reported either as (i) noncovalent interactions or as (ii) interactions that could be noncovalent based on prior studies.

4.7.1 Synthetic Methods toward Graphene/Nanostructure Hybrids

Multiple methods have been developed to deposit nanoparticles onto G ranging from the traditionally applied chemical solution deposition methods (210-212) to electrochemical, (213) ultrasonication, (214) and laser synthesis (215) deposition methods, among many others. In this section, a few of the novel techniques toward G nanoparticle materials are described.

Liu et al. (216) have demonstrated the simultaneous reduction of GO and deposition of Ag nanoparticles onto the rGO surface using an electron beam method. The authors of this study showed that the resistivity of the Ag/rGO material as well as the Ag nanoparticle size decreased with an increase in electron beam radiation dosage (167.96 and 27.52 nm at 70 and 350 kGy, respectively). The benefits of this method are apparent with the short time needed for synthesis as well as the ease of nanoparticle manipulation by dosage variation. In another study, Hui and co-workers (214) have shown that Ag nanoparticles of varying sizes can be uniformly deposited onto a GO substrate using ultrasonication in the presence of Vitamin C as a reducing agent. The authors showed that, in general, the size of the Ag nanoparticles is related to ultrasonication time with longer times resulting in larger nanoparticles. This observation of increasing size with ultrasonication time was attributed to the Ostwald ripening process. However, it should be noted that at sonication times above 20 min, both small and large nanoparticles are obtained, and a decrease in uniformity is also observed. The size of Ag nanoparticles deposited on rGO surfaces has been elaborated on further by Haider et al. (217) who showed that by using very dilute concentrations of AgNO₃ in sequential reduction reactions, a nanoparticle size of 4–50 nm can be obtained. This size modification was shown to be critical to the antibacterial properties of the Ag nanoparticle-rGO material against E. coli with an average size of 20 nm proving most efficient.

In another study, Shi et al. (218) have shown that a CuS/rGO composite can be prepared using a sonochemical method where CuCl₂ and GO were dispersed in ethylene glycol with the use of thioacetamide as a reducing agent. The as-prepared material exhibited a large surface area of 993.5 m² g^–1 and a much improved methylene blue photocatalytic activity as compared to bare CuS nanoparticles. It should be noted that these sonochemical methods are probably beneficial toward industrial scale synthesis as they can proceed on a large scale and at low synthesis temperatures. GO has also proved to be a suitable substrate for the challenging synthesis of single phase nanoparticles such as Cu₂ZnSnS₄, as demonstrated by Thangaraju and colleagues. (219) In this study, they showed that Cu₂ZnSnS₄ nanoparticles can either be deposited on GO by sonication in oleylamine or grown in situ using a hot injection method under a N₂atmosphere. The benefit of these growth methods for the Cu₂ZnSnS₄ material is that it affords a relatively simple approach whereby one is able to tune the absorption nature of the optoelectronic material.

Multiple groups have coated nanoparticles with polymers or other surfactants, which can then be attached to G-based templates. For example, Bera et al. (220) have shown that rGO can be functionalized with 0D, 1D, and 2D CdS nanoparticles; in this method, the nanoparticles are functionalized with 4-aminothiophenol before sonication with GO and subsequent hydrazine reduction. It should be noted that surfactant use is not limited to nanoparticle modification, with Wang and colleagues (221) showing that Pt nanoparticle decorated 3D G assemblies can be obtained when the amphoteric surfactant sodium lauryl aminopropionate (SLA) is used. Initially, the 3D GO structure is formed by sonicating GO with SLA. This formed 3D material was then modified with Pt nanoparticles using a hydrothermal synthesis method, which employs the added sodium lauryl aminopropionate as a reducing agent. On the other hand, it is also possible to modify the G surface with an organic functionality that is then able to attach a nanoparticle through well-known ionic interactions. In this way, Atar and colleagues (222) have shown that a GO modified using 2-aminoethanethiol can be successfully used to attach Fe@Ag core–shell nanoparticles through formation of an Ag–S ionic bond. Through functionalization of GO nanoribbons with cysteamine, it has been shown that Ag nanoparticles can not only be attached to the cysteamine chain through Ag–S bonds, but also on the GO basal surface. (223) These Ag nanoparticle functionalized GO nanoribbons then assemble into cube-like Ag nanoparticles agglomerates, which are believed to form through the initial cubic shape formation of the cysteamine functionalized GO nanoribbons.

The synthesis of CVD G with nanoparticles deposited on one side (asymmetrically) or both sides (symmetrically) has been reported by Toth et al. (224) Remarkably, the authors showed that in the symmetric deposition of nanoparticles, it is possible to deposit either the same metal or different metals. To obtain the single sided deposition, the authors used a redox reaction, which relied on the simultaneous oxidative etching of the Cu foil on which the G was grown and the reductive deposition of the desired nanoparticles. To deposit the second metal on the opposite side, the asymmetrically deposited G is floated on an aqueous solution containing the desired metal salt; after this flotation an organic layer containing a reducing agent is layered over the G sheet. As such, the second deposition occurs at an aqueous–organic liquid/liquid interface (see Figure 52).

Figure 52. Schematic of the synthesis method used to prepare symmetrically deposited CVD graphene sheets with different metals on either side. Reprinted with permission from ref 224. Copyright 2015 Wiley-VCH.

The layer by layer self-assembly of negatively charged CdS quantum dots onto GO modified with poly(allylamine hydrochloride), that is, positively charged, has been reported by Xiao et al. (225) toward forming nanofilms with photoelectrochemical and photocatalytic applications. This self-assembly method affords the electrodes formed with a highly efficient charge separation under photoelectrochemical conditions due to the stacked nature of the material, which results in close interfacial contact between the rGO and the CdS. The improved charge separation was also noted in the photocatalytic reduction of aromatic nitro compounds, with the CdS/rGO layered material showing almost double efficiency as compared to the layered CdS sample. One of the major challenges facing G materials in photoelectrochemical water splitting applications is the creation of uniform films with active sites for the catalytic oxygen and/or hydrogen reactions, and as such this layer-by-layer method holds promise for future applications.

The deposition of nanoparticles onto doped and/or functionalized G is another important and growing field of research in G nanoparticle systems. In this field of study, noble metal nanoparticles have been deposited on various doped G materials. Normally, nitrogen-doped G is used, see section 4.7.2, (213, 226) and this is probably due to the ease with which N-doped G can be synthesized. (227, 228) The deposition of Pt nanoparticles onto thiol functionalized thermally reduced graphene oxide (TrGO) by the thermal decomposition of the organometallic precursor methylcyclopentadienyl-trimethylplatinum(IV) in ionic liquid systems has been demonstrated by Marquardt et al. (229) In this synthesis procedure, thiol functionalized TrGO with varying amounts of thiol functionality can be achieved using various sulfur sources; it should be noted that the sulfur source used determines the thermal stability of the prepared materials during the high temperature Pt deposition process. The authors believe these methods can be applied to produce catalysts toward fuel cell technology, and as the materials display high thermal stability during Pt deposition this seems a reasonable assumption. In another high temperature process, Bi nanoparticle enriched nanoporous carbon has been formed on TrGO through the thermal decomposition of a Zn containing zeolitic imidazolate framework-8/GO hybrid material, followed by infiltration and chemical reduction of Bi(NO₃)₃. (230) This material was then applied in the fabrication of a selective and sensitive heavy metal electrochemical sensor.

A study by Wei and co-workers (231) has shown that electrochemically exfoliated G can be functionalized with Si, Fe₃O₄, and Pt nanoparticles by use of the solution-processable polyaniline emeraldine base (PANB), which provides functionalization sites. The use of the PANB is interesting as it leads to uniform coating of nanoparticles on the G surface, while the coating concentration can be determined by adjusting the ratio of PANB used in the synthesis step. An additional use of the PANB is that it provides unique electrical properties to the G by acting as a dopant. Because of these properties, the Si/PANB/G material was successfully applied in LIBs as an anode, and these properties are further discussed in section 4.7.2.

The growth of precisely aligned AuCN nanowires on CVD G has been reported by Lee et al., (232) who used a simple room-temperature solution growth method where the graphene substrate is floated on the surface of a precursor containing solution. The nanowires formed have dimensions of approximately 94 nm × 10 nm × 3 nm, and are aligned along the zigzag lattice directions of the graphene. This result is of interest as the precise control of nanoparticles in G-based materials is essential toward novel applications of nanoparticles, as well as G-nanoparticle systems. Additionally, they showed that the G–AuCN nanowire system can be used to create precise G nanoribbons by oxidizing the unprotected G using O₂ plasma and then removing the AuCN. The authors also noted that the grain boundaries of G can be visualized using this nanowire technique, with similar results reported by Yu et al. (233) who showed that the deposition of Au nanoparticles using thermal evaporation can be used to visualize grain boundaries. Importantly, in this study, the authors showed that different types of grain boundaries and wrinkles on the G surface can be differentiated; this is in contrast to previous G boundary visualization studies, which have focused only on defects and not the type of defect present. (234-236)

A novel method to obtain Ni₃S₂/rGO 3D frameworks using bacteria has been presented by Zhang and colleagues. (237) In this study, Bacillus subtilis was mixed with an aqueous solution of nickel acetate and GO, after which the solution was reduced and spray deposited onto a Ni foam substrate (see Figure 53). This porous Ni₃S₂/rGO material was then applied as a supercapacitor with a specific capacitance of 1424 F g^–1 at a current density of 0.75 A g^–1. Additionally, with cycling, that is, 3000 cycles at 15 A g^–1, 89.6% of the initial capacitance of 1242 F g^–1 was still delivered.

Figure 53. Schematic showing the synthesis of the Ni₃S₂/rGO 3D framework. Reprinted with permission from ref 237. Copyright 2013 American Chemical Society.

Nanoparticles coated with a carbon layer are of importance to Li-ion batteries as well as other applications. (238-240) Sengar and colleagues (240) have shown that metal (Pd or Cu)/G core/shell materials can be produced using a continuous flow gas-phase synthesis setup. The use of a spark generator using Pd or Cu electrodes was applied in this setup to form the metal core, and as such it is possible that this method could be expanded to multiple other metal/G core/shell materials. An additional benefit of this setup is that it employs an electrostatic precipitator, which allowed the authors to deposit the as-formed composite material on any substrate desired. In a study by Moon and colleagues, (241) it has been shown that Au nanorods coated with rGO, formed using a Xe lamp irradiation process with ammonium hydroxide as a reducing agent, are far more impressive photoacoustic bioimaging agents than uncoated Au nanorods. The authors believe the photoacoustic signal in this material is amplified due to (i) rGO being a very efficient heat transfer layer, and (ii) the Au nanorods’ ability to enhance the light absorbing properties of the rGO.

The use of Pt nanoparticles to combat restacking of G sheets was reported early on by Si and Samulski. (242) These authors showed that the capacitance of this Pt–G material can be increased 19 times as compared to stacked G sheets. In a similar manner, Au nanoparticles deposited on ErGO (243) and Co₃O₄ nanoparticles deposited on G (244) have been utilized as spacers to prevent G sheet restacking, thereby increasing the capacitance of the as-formed materials. Likewise, a report by Liu et al. (245) has shown that ultrasmall Ni(OH)₂ nanoparticles can be used to prevent restacking in rGO sheets when forming a Ni(OH)₂–rGO material. Interestingly, in this report the authors showed that the Ni(OH)₂ nanoparticles can also be used as a recyclable sacrificial spacer, with the rGO material formed using an acid dissolution process of the Ni(OH)₂–rGO material maintaining the nonstacked structure.

4.7.2 Decoration of Graphene and Graphene Oxide with Nanostructures for Catalytic Applications

Besides the novel techniques mentioned in the previous section, traditional solution-based methods are being developed for G/nanoparticle systems, and exciting developments are being obtained when templates are used. For example, it has been shown by Tiwari et al. (246, 247) that ultrasmall Pt nanoclusters (∼1 nm) and Pt nanodendrites can be deposited onto a GO scaffold using ssDNA as a template. In these synthetic methods, the authors showed that the Pt nanostructure formed was determined by the Pt salt used in the synthesis (see Figure 54). Remarkably, these systems prove to be excellent catalysts for the oxygen reduction reaction (ORR), with catalytic activities higher than the 2015 U.S. Department of Energy targets. Importantly, these catalysts also exhibited an impressive stability (∼95% after 10 000 cycles) when compared to commercially available ORR catalysts (∼40% after 10 000 cycles), thereby showing their applicability in commercial systems.

Figure 54. Synthesis of (a) Pt nanodendrites and (b) Pt nanoclusters deposited onto GO using DNA as a template. Panel (a) reprinted with permission from ref 246. Copyright 2013 American Chemical Society. Panel (b) reprinted with permission from ref 247. Copyright 2013 Nature Publishing Group.

One well-known benefit of using graphene-based materials as a scaffold for nanoparticles in catalytic reactions is the enhanced stability that this affords the nanoparticles. For example, this phenomenon has been noted in the research conducted by Huang et al. (248) who showed that Pd nanoparticles deposited on chemically rGO (CrGO) show enhanced stability in electrocatalytic activity toward the ORR in the presence of ethanol as compared to commercially available catalysts, that is, a current density of 0.055 versus 0.007 A mg^–1. This composite material was formed through a citrate catalyzed redox reaction initiated by irradiation using a 500 W mercury lamp, with the authors showing that this synthesis procedure can be extended toward Au–CrGO and Pt–CrGO composites. In another study, Yin and co-workers (249) have shown that Au, Pd, and Pt nanoclusters can be deposited onto CrGO sheets without the use of surfactants by simple sonication of dilute AuCl₄^3–, PdCl₄^2–, and PtCl₆^4– solutions with CrGO dispersions. The Au/CrGO material was tested as an ORR catalyst, and while the performance of this catalyst was not comparable to commercial Pt/C ORR catalysts, it displayed an enhanced tolerance to methanol as well as a higher stability (16% versus 50% activity loss after 40 000 s).

The oxidation of CO over a rGO supported Pd nanoparticle catalyst has been demonstrated by Liu and co-workers. (250) The catalyst was produced using an impregnation and hydrogen reduction method, with the authors showing that the Pd surface is essential to the oxidation even though the catalyst presents with a layer of PdO_x. The as-produced catalysts were shown to be very stable for CO oxidation at temperatures of 120 °C with no observable decrease in catalytic activity even after 24 h time on stream; in contrast, at 100 °C a decrease in activity was noted, which was attributed to difficulty in dissociation of adsorbed O₂ on the Pd nanoparticles. Similar studies have shown that Pt–rGO (251) and Pt–Ni–rGO (252) can be used in the oxidation of CO, although these studies did not report long-term catalytic stability.

Most high activity ORR catalysts reported make use of precious transition metals; however, high cost of these metals limits their application, and as such the search for cheaper transition metals is highly desired. In this regard, Guo et al. (209) have shown that Co/CoO (8 nm core/1 nm shell) nanoparticles deposited onto a TrGO substrate display an activity equivalent to commercially available Pt/C ORR catalysts in alkaline media. The catalytic activity is determined not only by favorable interactions between the TrGO and the nanoparticles, but also size tuning of the Co/CoO core/shell. Interestingly, the ideal core/shell dimension could be obtained by simple exposure of the as-formed Co nanoparticles to ambient conditions, thereby avoiding costly and time-consuming tuning steps. Last, while these catalysts did degrade with time, their stability was far improved as compared to the commercial Pt/C catalyst and Co/CoO nanoparticles deposited on Ketjen carbon.

The use of doped graphene materials has garnered wide interest due to the intrinsic ORR catalytic activity of N-, S-, and P-doped G. (253-255) Doubt has been cast on this ORR activity being due to the G material, with Wang and colleagues (256, 257) showing that this activity is instead caused by trace metal impurities. Regardless, Zhou and co-workers (226) have shown that Ag nanoparticles can be deposited onto N-doped rGO using a simple solution method, and these materials outperform Ag nanoparticles deposited onto rGO as ORR catalysts. The authors of this study showed for the first time that there is a chemical interaction between the Ag nanoparticles and the N-doped CrGO. As this interaction is not present in the case of Ag/CrGO, Ag nanoparticles, and CrGO, the authors believe this Ag–N interaction is the origin of the ORR activity. This material is interesting as it is cheaper than traditional ORR catalysts and shows methanol tolerance, which is in contrast to commercially available Pt-based ORR catalysts that show negligible activity when methanol is introduced into the test system. In a related study, Jin et al. (213) have shown that Ag nanoclusters (∼2 nm) can be electrochemically deposited onto a N-doped GO surface using ssDNA as a template. These Ag–GO catalysts were then applied as ORR catalysts, and while these systems do not exhibit activities that can rival the Pt–GO-based systems, the authors did show that these Ag-based ORR catalysts are tolerant toward methanol, showing no decrease in catalytic activity.

A recent report by Duan and colleagues (207) has shown that not only is the doped graphene material important, but the catalytic activity can be further tuned by altering the nanoparticle shape. In this study, the authors utilized hydrothermal conditions with the addition of either 1-butanol, ethanol, or 1-pentanol in the presence of NH₄OH to deposit sphere, cubic, or ellipsoid Mn₃O₄ nanoparticles onto N-doped CrGO, respectively. The ellipsoid Mn₃O₄ nanoparticle N-doped CrGO material exhibited an onset potential of −0.13 V and a current density of 11.69 mA cm^–2 at −0.6 V, as compared to the cubic material, which exhibited an onset potential of −0.16 V and a current density of 9.38 mA cm^–2. Additionally, as for the other N-doped G materials, the Mn₃O₄ containing catalyst displayed enhanced tolerance to methanol as compared to a commercial Pt/C ORR catalyst.

The application of G materials as catalysts in the important electrochemical hydrogen evolution reaction (EHER) has been reported by various groups. (258-261) The use of Pt metal as the EHER catalyst is widely known; however, the cost of this metal requires innovative methods to either reduce its usage or replace it. In this vain, Bai and colleagues (262) have shown that Pd–Pt core–shell nanocube structures deposited onto rGO can be used as effective EHER catalysts. The authors showed that a 0.8 nm thin layer of Pt deposited onto a Pd nanocube resulted in the largest current density, and as such a large reduction in the Pt metal affords improved activity, which is desirable for industrial applications (see Figure 55). (260) The increased reactivity of this core–shell nanocube design is attributed to the surface polarization that occurs due to differences in the work functions between the Pt and Pd, which then increases the EHER performance of the Pt surface.

Figure 55. Polarization curves obtained for the Pt–Pd–rGO EHER catalysts, with different Pt thickness and equal Pd loading amounts. Pt–Pd–rGO I, Pt–Pd–rGO II, and Pt–Pd–rGO III show Pt layer thicknesses of 0.8, 1.8, and 3.2 nm, respectively. Reprinted with permission from ref 262. Copyright 2014 Wiley-VCH.

In attempts to replace Pt as the catalyst, Youn et al. (261) showed that Mo₂C, Mo₂N, and MoS₂ nanoparticles can be deposited onto a CNT–GO support using a urea or thiourea-glass route. The as-obtained material was dried and calcined at 750 °C to afford Mo₂C, Mo₂N, or MoS₂/CNT–TrGO catalysts, which were applied toward the EHER, with the Mo₂C/CNT–TrGO catalysts affording the best activity of the three newly synthesized catalysts. It was further shown that the Mo₂C/CNT–TrGO materials’ onset potential (62 mV) was far improved as compared to Mo₂C deposited on CNT (120 mV), TrGO (150 mV), and carbon black (135 mV). This improvement in activity is believed to be due to the excellent conductivity of the CNT–TrGO support, as well as the three-dimensional stacking structure of the support. Building on this work, He and Tao (260) showed that MoC (∼2.5 nm) and Mo₂C (∼5.0 nm) nanoparticles can be deposited onto TrGO surfaces, and these catalysts were found to be highly stable with a negligible decrease in current density after 20 h of continuous EHER catalysis. Yan et al. (263) have shown that a WN/rGO (3 nm WN nanoparticles) material can be phosphorylized post synthetically using NaH₂PO₂ as a phosphorus source in a furnace at 800 °C, and this resulting P–WN/rGO (4 nm WN nanoparticles) material can be used as an EHER catalyst. This phosphorylation step is beneficial, as it affords the catalyst enhanced stability upon recycling with only a 34 mV loss as compared to a 111 mV loss for the WN/rGO material after 5000 cycles. Additionally, a lower onset overpotential for the EHER is required for the P–WN/rGO material as compared to the WN/rGO material, that is, 46 versus 114 mV, respectively.

G-based materials have additionally been tested as methanol oxidation catalysts and hydrogen generation catalysts from formic acid, for application in fuel cells. (264, 265) Chen et al. (264) have shown that highly dispersed AgPd nanoparticles can be deposited onto a rGO surface using a Co₃(BO₃)₂ coprecipitation and subsequent etching method. The authors showed that the coprecipitation and etching method prevents aggregation of the AgPd nanoparticles on the rGO surface. The resulting (Co₆)Ag_0.1Pd_0.9/rGO catalyst exhibited an enhanced formic acid dehydrogenation activity as compared to the Ag_0.1Pd_0.9/rGO catalyst prepared using a direct deposition method. Interestingly, this catalyst exhibited the highest turnover frequency, 2756 h^–1, reported for the formic acid dehydrogenation reaction at 323 K as compared to the previous 2623 h^–1 reported for Pd/MSC-30. However, it should be noted that this trend is reversed at an operation temperature of 298 K, 453 versus 750 h^–1. Yang et al. (265) have shown that preformed Pt nanoparticles can be deposited onto a sulfonated G (sG) support with a far greater density to give Pt/sG. The as-formed Pt/sG material was subsequently adhered to a glassy carbon electrode using poly(vinyl alcohol) and then applied as a methanol oxidation catalyst. The authors showed that the use of this sG support leads to an enhanced catalytic stability (9% activity loss) as compared to the use of an rGO support (∼20% activity loss). Additionally, the Pt/sG catalyst exhibited an enhanced catalytic activity as compared to Pt/C and Pt/rGO with mass activities after 200 cycles of 2156.54, 294.09, and 1162.03 mA mg^–1 Pt, respectively. Utilizing a surfactant-less two-step solvothermal and microwave synthetic method, Chen et al. (266) have shown that a Pd@Pt core–shell nanoflower supported on rGO can be synthesized. Remarkably, the nanocrystals produced using this method exhibit an extremely high lattice matching ratio, and as such no grain boundary is observed and the material can be considered as a pseudo Pd–Pt alloy. The as-synthesized material was applied as a methanol oxidation catalyst and exhibited an impressive mass activity of 9.23 A mg^–1 Pt with enhanced stability upon recycling as compared to other tested catalysts. The authors believe this enhanced activity is largely due to the surface-clean multimetallic nanocrystals produced in the surfactant free process.

The use of catalysts in organic reactions is very well-known, and as G has been shown to improve catalytic ability due to enhanced stability, there is an expanding field wherein G/nanoparticle systems are being applied in organic catalysis. For example, Moussa and colleagues (215) have shown that Suzuki–Miyaru, Heck, and Sonogashira cross-coupling can be achieved using Pd nanoparticles deposited on partially CrGO. In this study, the nanoparticles were deposited onto the GO surface, which was simultaneously reduced, through a redox reaction that was initiated by irradiation using a 532 nm laser source. It should be noted that, while these catalysts displayed extremely high activity, this activity dramatically decreased upon recycling with an average activity loss of ∼50% after 4 cycles. This loss in activity can be attributed to an increase in average particle size due to agglomeration, which in turn leads to a reduced catalytic surface area. In a related study, Metin and colleagues (267) have shown that Suzuki–Miyaru cross-coupling reactions can be catalyzed using a Ni/Pd core/shell nanoparticle system deposited on GO. These catalysts proved to be not only very stable and effective for the catalysis reactions probed, but they could easily be recycled with an efficiency of 98% conversion in the fifth reaction run. In another study, Putta and co-workers (268) have shown that the Suzuki–Miyaura and Heck–Mizoroki C–C cross-coupling reactions can take place in water under atmospheric conditions, when Pd nanoparticle catalysts are attached to rGO using cyclodextrin. This result is remarkable as previous studies using G-based materials have required the use of Schlenk apparatus and/or elevated pressures for the coupling to proceed. Last, Heck reactions have been catalyzed using catalysts consisting of Pd nanoparticles deposited on G foams manufactured using a gas–liquid interfacial plasma technique. (269) The use of G foam holds the benefit of an increased surface area as compared to Pd/rGO materials synthesized using the traditional solvothermal methods. Importantly, all of these C–C cross-coupling reactions utilizing G-based materials mentioned here do not require the use of phosphines, and as such are more environmentally benign.

The increased catalytic activity of G nanoparticle systems has been applied in sensors where an enhanced catalytic activity can lead to an improved limit of detection and/or sensitivity. (270) Duy-Thach and Chung (210) have shown that Pd nanocubes deposited onto a GO support with subsequent reduction can be utilized as a fast, reproducible, and sensitive hydrogen sensor. The sensor exhibited negligible response to O₂, NO₂, CO, CO₂, and N₂, thereby showing a good selectivity for H₂ with a limit of detection of 6 ppm at a working temperature of 50 °C. This sensing mechanism is based on the well-known adsorption of H₂ molecules on Pd, where this hydrogen adsorption in turn leads to improved electron transfer between the nanoparticle and the G surface. (271) As more electrons flow from the nanocube, there is a change in the rGO charge carrier density, which improves the sensitivity for H₂ as the G material used in hydrogen detection is normally p-doped (see Figure 56). In another study, Li et al. (272) have shown that a highly dispersed PtPd nanoparticle rGO system synthesized using an ionic liquid functionalized GO can be used in the enzyme-less detection of glucose. The use of the ionic liquid functionalized GO is critical to the synthesis of the highly dispersed and small bimetallic nanoparticles, 3.4 nm for Pt(50)Pd(50)–IL(100)–rGO as compared to 6.3 nm for Pt(50)Pd(50)–rGO (see Figure 57). (272) At 0 V versus a Ag/AgCl electrode, the Pt(50)Pd(50)–IL(100)–rGO material exhibited a limit of detection of 2 μM for glucose, with negligible response toward the competing analytes ascorbic acid, uric acid, and dopamine.

Figure 56. Charge carrier density in a graphene sensor versus hydrogen concentration. Reprinted with permission from ref 271. Copyright 2010 Elsevier B.V.

Figure 57. Synthesis of rGO/Pt–Pd supported catalysts. Reprinted with permission from ref 272. Copyright 2014 Elsevier B.V.

The use of graphene materials in enhanced photoelectrochemical hydrogen evolution has been demonstrated by multiple groups. (197, 273, 274) One method to improve the hydrogen evolution of p-type MoS₂ catalysts is to deposit the MoS₂ nanoparticles onto N-doped rGO, as Meng and colleagues (275) have shown. The authors of this study showed that the MoS₂/N-doped rGO catalyst exhibited a 3-fold increase in activity as compared to the MoS₂/rGO catalyst. As the surface areas of the catalysts are comparable, the authors concluded that this increase in performance must be attributable to the N-doped G. Wang et al. (276) have shown that the Au–P25–rGO complex can be prepared using a simple one-pot microwave assisted hydrothermal synthesis. Interestingly, this material was then applied in visible light hydrogen production, with the Au nanoparticles shifting the visible light response of the TiO₂, which is normally only active in the UV region. (277) In the Au–P25–rGO sample, the rGO leads to an impressive improvement in the quantum efficiency, that is, 4.1% as compared to 2.4% for the Au–P25 sample.

An interesting method to simultaneously deposit Pd nanoparticles and dope nitrogen into G has been developed by Vinayan and colleagues. (278) In this synthesis procedure, the authors employed a simple solar exfoliation of a PdCl₂/GO–melamine composite material using an ordinary convex lens to obtain Pd/N-doped solar rGO. This produced material was then tested as a hydrogen storage material, governed by the hydrogen spillover mechanism, and exhibited a hydrogen storage capacity of 4.3 wt % at 25 °C and 4 MPa.

4.7.3 Decoration of Graphene and Graphene Oxide with Nanostructures for Application in Lithium-Ion Batteries

Recent reviews by Tuček et al. (279) as well as others (280, 281) have highlighted the importance of G materials in LIBs. As such, this section should be considered as an update and highlight of these excellent reviews.

TiO₂ is a cheap and environmentally friendly material with a large cycling ability that can be applied as a cathode material in LIBs, and as such Li and co-workers (208) have developed a sol–gel synthesis method to obtain highly dispersed and controllable 5 nm in size TiO₂ (anatase phase) nanoparticles deposited on rGO. (208) This precise nanoparticle size control was obtained by adding tetrabutyl titanate to an ethanol dispersion of GO, which contained a small amount of ammonia as a reducing agent. The synthesized material was then applied in an LIB setup, as an anode, and exhibited a specific capacity of ∼94 mA h g^–1 at 59 °C, which is in contrast to a mechanically mixed TiO₂/rGO material that exhibited a specific capacity of ∼41 mA h g^–1. This improvement in performance as compared to the mechanically mixed sample was attributed to an increase in surface area, G conductivity, smaller nanoparticle size, as well as G layer thickness, which was ≤3 layers. In a similar way, ultrasmall ∼5 nm MoO₂ nanoparticles have been deposited onto TrGO to improve the slow lithium insertion kinetics and volume expansion that MoO₂ anode materials usually suffer in LIBs. (282) In this study, the authors showed that not only decreasing the size of the MoO₂, but the presence of the G support, improves the reversible capacity of the MoO₂ material (765.3 mA h g^–1 for MoO₂/TrGO versus 533.9 mA h g^–1 for MoO₂). The one problem facing TiO₂ use in LIBs is its low capacity; for this reason, Pan et al. have shown that the capacity can be increased when the TiO₂ is coupled to a high capacity material such as Fe₃O₄ through codeposition of the nanoparticles onto exfoliated G sheets (EGS). (283) This TiO₂–Fe₃O₄/EGS material was then applied as an anode in LIBs and delivered a reversible capacitance of 524 mA h g^–1 at 1000 mA g^–1, which is remarkably larger as compared to the value of 175 mA h g^–1 at 100 mA g^–1 reported by Li et al. (208) This work showed that the introduction of a high capacitance material with TiO₂ is able to improve the overall capacitance while retaining a high cycling ability.

The use of Si in LIBs is of interest due to its high theoretical capacitance; however, this material expands rapidly on lithium ion adsorption, and as such its capacitance drops rapidly on cycling. (284) To prevent this expansion, Zhu and colleagues (285) have deposited 30 nm Si nanoparticles onto rGO using a magnesiothermic reduction reaction of a SiO₂/GO composite at 700 °C. The ratio of magnesium to SiO₂/GO composite material is critical to obtaining the desired product, with a 1:1 ratio providing the 30 nm Si nanoparticle/rGO material. This material was then applied as an anode in LIBs and showed a minimal decrease in capacitance of 1300 mA h g^–1 at 100 mA g^–1 after cycling at various current densities (see Figure 58). (285) Another method employed to improve the cycling capacity of Si has been demonstrated by Hassan and colleagues (286) who showed that Si nanowires can be deposited onto a Ni nanoparticle–TrGO support using a novel high temperature thermal shock and deposition method. Importantly, the material was coated with a 2 nm layer of amorphous carbon. When this material was then applied as an anode in LIBs, the material exhibited an improved cycling stability (550 mA h g^–1 at 6.8 A g^–1 for the 100th cycle), which is attributed to the synergy between the Si nanowires and the Ni–TrGO support. It is interesting to note that in this study the general morphology of the >100 nm long Si nanowires was retained, although significant fragmentation and swelling occurred, with this shape retention being attributed to the amorphous carbon layer coating the surface. To improve the stability of Si nanoparticles on electrochemically exfoliated G, a polyaniline emeraldine base layer has been used as described by Wei et al. (231) This material exhibited a reversible capacity of 1710 mA h g^–1 at 0.42 A g^–1, and a capacity retention of 86% after 100 cycles. In a study by Zhou et al., (287) it has been shown that G sheets can be bridged and orientated using Si nanoparticles, which act as hinges between the sheets. In this synthesis, the Si nanoparticles coated with bovine serum albumin and GO are dispersed together, and then electrostatic self-assembly takes place during a vacuum filtration process. The benefit of using this material is that it can be applied directly as a self-supporting anode in LIBs with an excellent stability and impressive gravimetric capacity of 1390 mA h g^–1 at 2 A g^–1.

Figure 58. Capacity of the Si/rGO material at various current densities upon cycling. Reprinted with permission from ref 285. Copyright 2013 Royal Society of Chemistry.

Similar to Si, Ge holds promise as an anode material in LIBs due to its large theoretical capacity, although it suffers cycling drawbacks due to expansion upon Li insertion. A study by Yuan and Tuan (288) has shown that a carbon-coated Ge nanoparticles/rGO material can be applied as an anode material in LIBs with large capacitance retention close to the Ge theoretical capacitance value. The C/Ge/rGO material exhibited a discharge capacity of ∼1100 mA h g^–1 at 0.2 C after 360 cycles with discharge rates ranging from 0.2 to 20 C. This material was additionally used to construct aluminum-pouch-type lithium-ion commercial type batteries, which offered a capacity of over 20 mA h; these batteries were then used to power an electric fan, a scrolling LED marquee, and LED arrays.

As the Si and Ge examples have demonstrated, the use of a carbon layer promotes recycling stability, and as such it would be expected that G can also act as a coating layer to improve recycling stability of materials in LIBs. In this vein, Shi and co-workers (238) have shown that hollow Li₃VO₄ microboxes coated with rGO can be applied as an anode material in LIBs. This material exhibits improved capacitance at larger discharge rates (223 versus 87 mA h g^–1 at 20 C), as well as recycling stability (378 versus 345 mA h g^–1 after 50 cycles at a current density of 20 mA g^–1), as compared to uncoated Li₃VO₄ microboxes. In another study, Hu and colleagues (239) applied a Kirkendall process to fabricate a γ-Fe₂O₃/G/amorphous carbon (hollow core–first shell–second shell) material by air oxidation of a Fe core/G/amorphous carbon material. The authors showed that the hollow core and G layer shell are important factors in the stability of the material upon recycling (833 mA h g^–1 at 1 C after 100 cycles) when compared to uncoated α-Fe₂O₃ nanoparticles as well as other reported α-Fe₂O₃/G and α-Fe₂O₃/carbon materials. (289, 290)

An alternative to LIBs are the sodium ion batteries (NIBs), which have a lower cost. However, these batteries are plagued with stability and performance issues, which are related to the limited choices of anode materials. (291) For this reason, Yu and colleagues (292) have proposed the use of Sb₂S₃ nanoparticles coating rGO as an anode material due to its large theoretical capacity of 946 mA h g^–1 as well as stability upon recycling. As compared to commercially available Sb₂S₃, the Sb₂S₃/rGO material shows negligible capacitance loss upon cycling, that is, 97.2% capacitance retention versus 50% after 50 cycles. From these results, we can see the critical role G can play in the future of NIBs, which can operate with large charge densities at a lower price.

G/nanoparticle materials have also been applied in lithium–sulfur batteries, where Xiao and colleagues (293) have shown that the deposition of a TiO₂/G layer on top of the porous CNT/S cathode leads to improved stability. While the TiO₂/G layer does not contribute to the charge capacity, it does inhibit the dissolution of the S cathode, which results in very low capacity degradation rates upon cycling. For this reason, the battery made with the TiO₂/G is able to supply a specific capacity of 1040 mA h g^–1 over 300 cycles at 0.5 C, while the S cathode coated only with G supplied 750 mA h g^–1 and the uncoated S cathode supplied 430 mA h g^–1.

Lithium–oxygen and lithium–sulfur batteries have been proposed as alternatives to LIBs due to their large specific energy density; however, they suffer due to capacitance decrease on recycling. To improve the capacity fading that occurs in these proposed batteries, due to irreversible reactions, Ryu et al. (294) have developed a Co₃O₄ nanofiber/G material, which they applied as the O₂ cathode in a Li–O₂ battery. The Co₃O₄ nanofibers were produced by an electrospinning process and then deposited onto pristine G (noncovalently functionalized using 1-pyrenebutyric acid) or rGO using sonication. The pristine G material proved to be important for cycling stability of the material with a discharge capacity of 10 500 mA h g^–1 after 80 cycles (see Figure 59). (294) This report shows that the use of G materials still holds much promise for batteries, with applicability in next generation energy devices.

Figure 59. Cycling performance of Co₃O₄ NPs (nanoparticles), Co₃O₄ NFs (nanofibers), Co₃O₄ NF/rGO composite, and Co₃O₄ NFs/GNF (graphene) materials under a specific capacity limit of 1000 mA h g^–1 in a voltage window between 4.35 and 2.0 V at a current density of 200 mA g^–1. Reprinted with permission from ref 294. Copyright 2013 American Chemical Society.

4.7.4 Decoration of Graphene and Graphene Oxide with Magnetic Nanostructures

A recent review by us has highlighted the importance of magnetic G materials in wastewater treatments, medical research, catalysis, etc., and as such this section should be considered as an update to this literature. (279)

In an early study by Chandra et al., (295) superparamagnetic Fe₃O₄–rGO hybrids were synthesized via the hydrazine reduction of a Fe₃O₄–GO precursor. These hybrid materials were subsequently applied in the removal of As(III) and As(V) from contaminated water samples. As the material showed near complete (99.9%) arsenic removal and magnetic separation, these types of material should be applicable in water purification.

The simple autoclave pyrolytic fabrication of Fe₃C (iron carbide) nanoparticles encapsulated by G has been reported by Hu et al. (296) An advantage of using G encapsulated nanoparticles is that they are separated from environments, which may decompose them. This was demonstrated for the Fe₃C nanoparticles, which exhibited stability in acid solution that normally degrades it. This G Fe₃C encapsulated material was subsequently applied as an ORR catalyst in basic media, with an onset potential (1.05 V versus RHE) and half wave potential (0.83 V) comparable to those of a commercially available Pt/C ORR catalyst. Importantly, this material shows negligible response to methanol introduction into the system as compared to the commercial Pt/C catalyst. In another study, Moussa et al. (297) have shown that the Fe-based nanoparticles (Fe₁₅–rGO, Fe₁₅K₅–rGO, Fe₁₅Mn₅–rGO, and Fe₁₅K₅Mn₅–rGO) deposited onto a rGO can be used in the highly stable and recyclable Fischer–Tropsch synthesis of liquid hydrocarbons from C₂H₄ gas. The advantage of using the G-based systems is that most of the systems tested tend to give minor formation of CH₄ and CO₂ with a large activity toward higher hydrocarbons C₈⁺. Of the G-based catalysts tested, the Fe₁₅–rGO exhibited the lowest CH₄ production (1.5%), yet exhibited a large C₂–C₇ hydrocarbon ratio of 32.0%; in contrast, the Fe₁₅K₅–rGO sample exhibited a 2.6% formation of CH₄ and the largest formation of C₈⁺ hydrocarbons (86.7%). These G-based materials exhibited an improved performance as compared to similar CNT-based materials, and the authors believe this is due to the accessibility of the iron carbide Fe₅C₂ active phase on the G support during catalysis.

An interesting study by Xu and co-workers (298) has shown that a 3D conductive Fe₃O₄/rGO aerogel can be fabricated through an rGO self-assembly and simultaneous Fe₃O₄ nanoparticle deposition. Interestingly, the as-synthesized lightweight material could be manipulated using an external magnetic field, while still maintaining its inherent conductivity (see Figure 60). (298) As the material maintains its conductivity upon magnetic deformation, the degree of strain along the axial and radial directions can then be determined by measuring the change in conductivity. For these reasons, the authors believe that this material holds promise in self-sensing soft actuators, microsensors, microswitches, as well as oil absorption and recycling.

Figure 60. (a) Magnetic deformation of the magnetic Fe₃O₄/rGO aerogel, (b) I–V curve and thermal conductivity stability of the aerogel, and (c) change in the electrical resistance of the aerogel as a function of the magnetic field-induced deformation. Reprinted with permission from ref 298. Copyright 2015 American Chemical Society.

Fe₃O₄/rGO composite materials as electromagnetic shielding/interference materials have been reported by multiple research groups. (299-301) The materials can be produced by either solution precipitation of Fe₃O₄ nanoparticles onto the rGO surface, (299) or the deposition of already formed Fe₃O₄ nanoparticles onto the rGO surface. (300) The mechanism of this interference is attributed to the radiation being reflected by the small G sheets compartments (which are kept separated by the Fe₃O₄ nanoparticles), and subsequently this radiation is then able to interact with the Fe₃O₄ nanoparticles, which dampens the radiation. As such, a composite material consisting of polystyrene/TrGO/Fe₃O₄ is able to shield electromagnetic radiation with an efficiency of more than 30 dB in the 9.8–12 GHz frequency range. (299) In contrast, when the polymer support was changed to polyvinyl chloride (PVC), an efficiency of only 13 dB in the 8–12 GHz range was observed. (300) It should be noted however that in the PVC example, the TrGO/Fe₃O₄ additive greatly decreased the flammability of the PVC as well as afforded the PVC more tensile strength (20.8% increase) and larger Young’s modulus (73.7% increase).

Kumar et al. (302) have shown that glass beads coated with a Fe₃O₄/rGO material can be used as simple multifunctional micro robots (microbot). The authors showed that by varying the external magnetic field between 40 and 110 mT, the average velocity of the microbot can be varied linearly from 1.8 × 10^–4 to 1 × 10^–3 m s^–1. Interestingly, as these microbots’ velocity can also be varied using chemical reactions and electric fields, the authors believe that the velocity can be increased or decreased even further. Demonstrating the practical applications of this microbot, the authors showed how it can be used to deliver cargo (∼1000 times heavier and ∼13 times larger in size than the microbot) inside a confined environment using a magnetically directed “drop-off” and “pick-up” mechanism.

Jiang et al. have shown that a Fe₂O₃–rGO composite can be produced using a supercritical CO₂ thermal reduction of a Fe(NO₃)₃·9H₂O and GO dispersion. (303) The authors then showed that a vertically or horizontally aligned Fe₂O₃–rGO paper can be obtained by filtration of a composite dispersion under a controlled magnetic field. The as-formed papers were then applied in H₂S gas sensing, with the vertically aligned paper showing more sensitivity than the horizontally aligned material. This report demonstrates that the structural orientation of the graphene sheets in any synthesized material plays a crucial role in maximizing efficiency.

4.7.5 Decoration of Graphene Nanostructures with Quantum Dots

The deposition of various quantum dots (QDs) onto G proceeds (in most cases) via a facile solvothermal process, and the application of these QD–G materials varying from photocatalysis, supercapacitance, LIBs and NIBs, photodetectors, photosensitizers, water purification, etc., has been demonstrated by multiple research groups. (304-311) It should be noted here that similar applications are being realized for materials containing GQDs (graphene quantum dots). (312-317) Other methods toward QD–G materials have been developed by Zhang and colleagues (316) who fabricated a UV photodetector by the atomic layer deposition of ZnO QDs onto G. The authors note that the ZnO nucleates at defect sites in the G, which leads to the formation of QDs instead of thin film layers as is normally found with atomic layer deposition methods.

Perhaps one of the more novel methods that could be employed to deposit QDs onto a G surface was hinted at in a study by Zeng and colleagues (308) who showed that the carcinoembryonic antigen could be detected using a novel CdS QD–GO photoelectochemical biosensor. The mechanism of detection relies on the horseradish peroxidase, which catalyzes the reduction of sodium thiosulfate with H₂O₂ to give H₂S, and this reacts with Cd²⁺ present in solution to form CdS QDs. As such, this study shows that enzymes could potentially be used in the deposition of QDs with a controllable size on a G substrate.

QD–G materials have been widely applied in the photoelectrochemical and dye-sensitized solar cell fields, with this largely being due to the transparency and conductivity of G materials, which make it a viable replacement for traditionally applied electrode materials. (304, 305, 318) In these studies, the G component of the solar cell is crucial in the separation of charge carriers and as such preventing recombination, which leads to an improved efficiency. Jung and Chu (319) have shown that the binding mechanism between the quantum dot and graphene is critical toward improved charge transfer efficiency between the components. In this study, the authors deposited capped CdSe QDs onto an rGO substrate using either covalent (aryl bond) or noncovalent (π–π interactions) attachment. Thin films of these materials were fabricated electrophoretically, and it was shown that the covalently attached CdSe QDs lead to an improved quantum efficiency as well as photocurrent density. It should be noted, however, that noncovalent attachment is beneficial toward an enhanced phototransfer processes between the CdSe QD and the G surface, as has been demonstrated by Guo and colleagues. (320) Interestingly, Hirose and co-workers (321) have shown that QD blinking can be suppressed in a CdTe QD–G system by spin coating a layer of polyvinylpyrrolidone or polyethylene glycol over the composite material. Photoluminescence blinking can lead to a decrease in efficiency, as it is essentially the random switching between ON and OFF states; as such this spin coating method holds promise toward the development of improved solar cell systems incorporating QD–G systems. Liu and colleagues (322) have demonstrated using fluorescence emission analysis that multiphoton emission in CdTe/ZnS QDs can be greatly enhanced when the QDs are deposited onto single layer CVD G. This enhanced multiphoton emission is believed to be due to a decrease in fluorescence lifetime, and hence fluorescence intensity, which results in a lower single-photon emission probability due to the presence of the G, which acts as a quencher.

The use of QD/G materials in energy materials that do not take advantage of the photocatalytic properties of the QDs has also generated interest. TiO–QD–rGO, Ge–QD–N-doped rGO, Co₃O₄–QD–rGO, and ZnO–QD–rGO are among the many materials that have been employed in LIBs. (310, 323-325) One of the major reasons to employ QDs in LIBs is that with a decrease in nanoparticle size, the volume expansion associated with lithium insertion and extraction is minimized, and as such the batteries are more stable than counterparts consisting of larger particles. In the synthesis of the Co₃O₄–QD–rGO material, Zhou et al. (325) showed that a microwave synthetic method can dramatically decrease the reaction time normally required for solvothermal synthetic methods.

Carbon-coated Fe₃O₄ QDs deposited on rGO have the additional structural stabilization benefit, besides size reduction, of avoiding detachment of the Fe₃O₄ QDs through an enhanced strong adhesive force between QD and G. (326) As such, a synthesized Fe₃O₄@C–rGO material exhibited a specific capacity of 940 mA h g^–1 at a current density of 150 mA g^–1, which is similar to results obtained for Fe₃O₄–G coated nanoparticles cross-linked into 3D G foams. (327) Xia and colleagues (310) have shown that an Fe₂O₃–QD–rGO material can be applied as an anode material in an asymmetric supercapacitor, with the cathode material being fabricated from a MnO₂ nanoparticle/rGO material. The Fe₂O₃–QD–rGO anode material exhibited a maximum specific capacitance of 347 F g^–1 when cycled between −1 and 0 V versus an Ag/AgCl reference electrode in a 1 M Na₂SO₄ aqueous solution. Additionally, the authors showed that the fabricated asymmetric supercapacitor can deliver an energy density of 50.7 Wh kg^–1 at a power density of 100 W kg^–1, with this supercapacitor exhibiting 95% retention of its initial capacitance after 5000 cycles.

A novel method for the deposition of PbS QDs onto GO has been presented by Tayyebi and co-workers (328) who used supercritical ethanol, which acted as a solvent, reducing agent, and surfactant in the reaction. Interestingly, the authors showed that the PbS QDs bind to the G surface through residual oxygen functionalities on the TrGO surface through Pb–O–C bonds; this in turn results in a reduced band gap, which one would expect to translate into an increased recombination rate. This counterintuitive phenomenon is believed to be due to the electron transfer from the conduction band of the PbS QDs into the TrGO, thereby leading to a decrease in charge recombination.

TiO₂ QDs deposited onto exfoliated G have been shown to be an effective precursor toward the formation of ultrathin TiO₂ films deposited onto glass substrates. (329) These G-containing TiO₂ QD materials exhibit improved photocatalytic efficiency when compared to G-containing TiO₂ nanoparticle materials, as well as G free TiO₂ QD. This is attributed to the larger contact area that occurs between the QD and the G surface as compared to the nanoparticle and G surface. In another study by Cao and colleagues, (330) it has been demonstrated that MnO_x QDs can be deposited onto a rGO substrate uniformly coated with TiO₂ nanoparticles using a UV and microwave synthesis method. The material synthesized in this method displays an enhanced dye degradation photocatalytic activity, as well as electrochemical and photochemical energy storage. Interestingly, this material can photochemically store energy, which can be utilized in antimicrobial activity in the dark with efficiency similar to penicillin, although UV irradiation leads to a far greater inhibition effect.

5 Applications of Noncovalently Functionalized Graphene and Graphene Oxide

ARTICLE SECTIONS

Jump To

Noncovalent functionalization through electrostatic, π-effects, van der Waals forces, and hydrophobic effects, etc., is an effective method for changing the physicochemical properties of nanofillers to improve their interfacial interactions in a material matrix. (331) Noncovalent functionalized nanomaterials containing G/GO exist in two forms: (i) nanospecies deposited onto the G surface and (ii) nanospecies encapsulated with G/GO. These materials have been applied in various advanced applications in the fields of energy materials, green chemistry, environmental science, nanodevices, catalysis, photocatalytic, biosensors, bioimaging, and biomedicine. In these subsections, we will give an overview of selected recent advanced applications wherein variously functionalized G/GO nanomaterials have been applied.

5.1 Energy Materials

Monolayer or few-layer G/GO structures are extremely efficient materials for adsorption of or encapsulation of nanoparticles. In fact, these nanoparticles exhibit a beneficial impact on G or GO-based electrochemical energy conversion and storage devices. (332-336) Campbell et al. (337) have evaluated the battery/supercapacitor performance of large surface area G modified with anthraquinone (AQ), where the AQ and G are bonded through π–π interactions. They reported that the gravimetric energy storage capacity of G macro-assemblies (GMAs) can be increased nearly 3 times (∼23 Wh kg^–1) by AQ. They also demonstrated that the AQ provides a battery-like redox charge storage capacity (927 C g^–1), while the inherent conductivity and capacitance of the GMAs are maintained. Kong et al. (338) have developed a MoS₂@G nanocable web composite, which was applied as an advanced high performance electrode materials for LIBs. The binder-free MoS₂@G hybrid electrode not only showed a large specific capacity (∼1150 mA h g^–1) and remarkable recycling performance (∼100% stability after 160 cycles at 0.5 A g^–1), but also exhibited a high-rate capability of 700 mA h g^–1 at the sweep rate of 10 A g^–1. It is believed that the improvement in the performance of the hybrid is due to the highly dispersed MoS₂ sheets, which accelerate the Li-ion transport, and shorten the Li⁺ ion diffusion paths. The authors believe that this 2D/2D hybrid nanoarchitecture leads to more active sites for Li⁺ insertion/extraction and as such could be applied as an electrode material in high performance batteries. TiO₂ materials are desired as anode materials in LIBs due to safety factors, low price, environmental benignity, and excellent cycle durability. Conversely, TiO₂ materials have a poor theoretical capacity and conductivity. To combat this, Yang et al. (339) employed a sandwich-like porous TiO₂/rGO hybrid (T-150, T-200, and T-240) as an anode electrode material for LIBs. These hybrid materials with porous structures and high electrical conductivity exhibited good stability (no decrease in capacity of 206 mA h g^–1 at a current density of 0.1 A g^–1 after 200 charge–discharge cycles) and a remarkably large reversible capacity of ∼128 mA h g^–1 at a current rate of 5 A g^–1 (see Figure 61). (339) The efficiency of these hybrids is attributed to (i) the porous TiO₂ nanocrystals whose small sizes reduced the diffusion length for Li insertion–extraction, as well as (ii) affording good contact with the electrolyte and the RGO sheets, which enhanced the conductivity of the hybrid.

Figure 61. (a) Charge–discharge voltage profiles of the T-200 hybrid cycled at 1.0–3.0 V at a current density of 0.1 A g^–1, (b) rate performances of T-200, C1, and C2 at various current densities, and (c) cycling performance of T-150, T-200, T-240, C1, and C2 at a current density of 0.1 A g^–1. Reprinted with permission from ref 339. Copyright 2015 Royal Society of Chemistry.

Ali et al. (340) have developed an iron fluoride hydrate/rGO material as a promising cathode material for NIBs. These materials displayed an impressive discharge capacity of 266 mA h g^–1 under a current density of 0.05 C, and a stable cycle performance (∼86% retain after 100 cycles). These properties suggest its applicability as a cathode material for NIBs. It should be noted that due to polarization effects and the large size of the Na⁺ ion, the rate capability of this iron fluoride hydrate/rGO material was lackluster. As such, further developments in the preparation methods of G or GO nanostructures and nanomaterials are required for G materials to be applicable in NIBs. MoS₂/rGO flake hybrids have been recently identified as a promising material for electrodes in NIBs. (341) The hybrids were synthesized in the form of layered free-standing papers, which were found to show a good cycling ability with stable charge capacity of 230 mA h g^–1. Moreover, these composite papers possessed a high average strain, thus considering them as ideal cantidates for exploitation in the field of large-area free-standing binder-free flexible electrodes for rechargeable applications. Qu and co-workers (342) have shown that rGO can be assembled into 3D porous networks using a dual substrate-assisted reduction and assembly (DSARA) method, which the authors believe can be applied in energy-related applications such as LIBs, fuel cells, photoelectric conversion devices, etc. In this study, the authors showed that a 3D DSARA-produced rGO porous network coated with NiO/Ni complexes exhibits a remarkable capacity (1524 mA h g^–1) with a stable high charge–discharge rate (600 mA h g^–1 after 1000 cycles). Additionally, a PdPt alloy deposited onto the 3D DSARA-produced rGO porous network displayed efficient catalytic performance for the ORR in fuel cells. (342) The formation of these 3D G structures can increase the specific capacity of a material through the introduction of porous channels, which facilitate ion transportation, and as such optimized 3D G nanostructures are critically important not only in ORR, but supercapacitor applications. (343) In this sense, Jung et al. (344) have reported that controlled porous aerogel structures can be formed from suspensions of electrochemically exfoliated G, and that this material can be applied as a supercapacitor electrode. Because of the 3D G aerogels’ large specific surface area, low density, and superior electrical conductivity, it showed a large specific capacitance (325 F g^–1 at 1 A g^–1) and good energy density (45 Wh kg^–1 in acid electrolyte) with high electrochemical durability. Jana and co-workers (345) have shown that GO can be noncovalently modified using sulfanilic acid azocromotrop (SAC), which is then reduced in a subsequent step using hydrazine monohydrate to give SAC–rGO (see Figure 62). This synthesized material was then applied as a supercapactitor electrode material, which showed a large capacitance (366 F g^–1 at 1.2 A g^–1), high energy density (25.86 W h kg^–1), and excellent power density (980 W kg^–1) with good cycling stability (∼72% retain after 5000 charge–discharge cycles). These impressive electrochemical properties are attributed to the redox reactions between the SAC–rGO materials’ SO₃H/OH functionalities and the H⁺ ions of H₂SO₄. (345)

Figure 62. Synthetic methods used to produce SAC–rGO (right bottom) and rGO (left bottom). A schematic of the electrochemical device used to measure the supercapacitance of the material is also shown. Reprinted with permission from ref 345. Copyright 2015 Royal Society of Chemistry.

5.2 Solar Cells

Solar energy is considered a possible alternative to the traditional fossil fuel energy sources due to the fact that the sun is essentially a free and continuous energy supply. Additionally, the cost of solar cells can be dramatically reduced when the efficiency of solar cells is increased; for example, a solar module that exhibited a 1% enhancement in its efficiency led to a 5% reduction in price. (346) G/GO exhibits potential as an optically conductive window as they allow a wide range of light wavelengths to pass through, that is, optical transmittance reaching ∼98%. (346, 347) Additionally, G/GO optical and electrical properties can be modulated through noncovalent interactions with metal complexes, which make it suitable for different types of solar cell applications. (346-350) Wang et al.’s (351) group have developed a solution-based low-temperature deposition procedure to manufacture the electron collection layer using a G/TiO₂ nanoparticle material as the electron collection layers in meso-superstructured perovskite solar cells. They found that the solar cells manufactured using this low-temperature process exhibit a significant photovoltaic performance, that is, power conversion efficiency up to 15.6%, which suggests that solar cells no longer need a high-temperature sintering process when TiO₂ is employed in the electron collection layer (see Figure 63). This enhancement in efficiency was ascribed to the synergetic effects between G and TiO₂ nanoparticles, where (i) G might reduce the formation of energy barriers at the interface between TiO₂ and fluorine doped tin oxide (FTO) and (ii) the superior charge mobility of G may provide improved electrical conductivity in the electron collection layer. (351) Kim and colleagues (352) have studied the optoelectronic properties of G thin films (thickness between 2–30 nm) prepared using a Langmuir–Blodgett (LB) assembly method. In this method, the G thin films are assembled by dip coating a glass substrate in a N-methyl-2-pyrrolidone (NMP) and water G dispersion. The authors found that the conductivity of the as-formed films can be tuned by increasing the lateral size and the density of the packing of the G platelets in the LB assembly. Fukuzumi et al. (353) reported a rapid photoinduced charge separation in ordered self-assembled layers of perylenediimide and GO (PDI–GO), where this self-assembly is believed to proceed via π–π and electrostatic interactions between the components in water. The authors believe that the π–π stacking between the components is necessary for efficient charge separation as it promotes a “pull effect”. This in turn leads to slow charge recombination due to holes being able to move easily on the G surface. In contrast, when this hybrid stack material is introduced into a polymer environment, the interlayer charge-hopping mechanism is interrupted due to loss of the self-assembly macrostructure, and this causes rapid back electron transfer from PDI^•– to oxidized GO, that is, faster recombination. (353) In another study, Dehsari and co-workers (354) developed a polymer solar cell (PSC) hole transport layer (HTL) by spin coating a thin layer of ultra large GO/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS/GO) material onto an indium–tin–oxide (ITO) anode. They showed that the optimized PSC with a PEDOT:PSS/GO HTL layer exhibits a power conversion efficiency of 3.39%, an enhancement of ∼12%, with respect to a PSC, which contains only a PEDOT:PSS layer. The improved power conversion efficiency is attributed to improved hole mobility and reduced radiative exciton quenching at the interface of the PEDOT:PSS/GO HTLs and the poly(2-methoxy-5(2-ethyl)hexoxy-phenylenevinylene) active layer. (354) Kymakis and co-workers (355) fabricated flexible organic photovoltaic devices (OPD) with in situ nonthermal photoreduction of spin-deposited GO electrodes. The GO films were reduced by the laser system and then were utilized as transparent electrodes in flexible, bulk heterojunction, OPDs, which open the possibility of replacing the traditional ITO substrate. The GO-based OPDs showed a power-conversion efficiency of 1.1% with 70% transparency. (355) Many reports on the good optical transmittance and excellent electrical conductivity of G layers have been published, (346-355) but studies are limited on the transparent conducting property by coating the G layers onto fabricated solar cells. Additionally, difficulties arise in the transfer of a uniform G/GO layer onto highly textured surfaces, and this may limit its possible large-scale production.

Figure 63. G–TiO₂ hybrid-based solar cell performance under simulated AM 1.5, 106.5 mW/cm² solar irradiation (red line), and that in the dark (black line). Reprinted with permission from ref 351. Copyright 2014 American Chemical Society.

Dye-sensitized solar cells (DSSCs) are attractive as they are environmentally friendly, economical, and exhibit high energy conversion efficiency. (356, 357) In DSSCs, the electrons are injected from photo-oxidized dyes into TiO₂ nanoparticles, and the resulting oxidized dyes are regenerated by electrolytes. At a counter electrode (CE), I^– ions reduce the oxidized dyes, yielding I₃^–, and the resulting I₃^– ions are finally reduced to I^–. Thus, the CE plays an important role in enhancing DSSC performance by catalyzing reduction of the electrolyte. The electron transport in disordered TiO₂ nanoparticles with a random transit path increased the charge recombination, thereby reducing the photocurrent and the efficiency of the DSSCs. Fabrication of photoanodes with a fast transport pathway is still a challenge for DSSCs. In this sense, Cheng et al. (358) prepared hybrid materials of anatase TiO₂ nanoparticles on rGO sheets (TiO₂@rGO) for application in DSSCs. These hybrid photoanode materials exhibited a better efficiency (7.68%) in DSSCs than that of the pure TiO₂ (4.78%), suggesting that the introduction of G accelerates the electron transfer and decreases the charge recombination. Bi and co-workers (359) developed a quasi core–shell structure of N-doped G/cobalt sulfide (NDG/CoS) as a CE for DSSCs, which exhibited a high short-circuit current density (20.38 mA cm^–2) and an energy conversion efficiency of 10.71% (see Figure 64). The remarkable performance of these DSSCs is attributed to the core of CoS nanoparticles coated with a shell of ultrathin NDG layers that act as conductive paths to overcome the problem of low conductivity caused by grain boundaries and defects between the CoS nanoparticles.

Much effort is still required to either replace Pt in DSSCs with less expensive alternative materials or to develop easier low-temperature approaches, which employ reduced amounts of Pt; in this vein, easy, cheap, and room-temperature processes are of vital interest for DSSC commercialization. Additionally, the DSSC energy conversion efficiency with various types of hybrid materials is still lower than ∼11%, which is much smaller than commercial solar cells. Thus, further developments are required to obtain a much larger DSSC efficiency to be compatible with the recent developments of perovskite solar cells, (360, 361) which shows ∼20% efficiency, although these perovskite-based devices are not yet stable enough for practical applications.

Figure 64. DSSCs performance with NDG/CoS, G/CoS, NDG, and Pt as CEs. Reprinted with permission from ref 359. Copyright 2014 Royal Society of Chemistry.

Noncovalent functionalization at the interface of G/GO by doping, chemical/physical modification, and nanoparticle coating could be one of the best approaches to greatly tune the nanostructure and chemophysical properties toward the development of high performance electrode materials in energy storage applications. Although several reports on noncovalent functionalization of G/GO with different morphologies as energy materials have been published, there is still a long way to go before its wide use in industrial applications.

5.3 Water Splitting

The production of hydrogen from H₂O would generate a new era of cheap, clean, and renewable energy such as hydrogen fuel cells and liquid fuels synthesized from syngas and CO₂. The electrocatalytic hydrogen evolution reaction (HER) from water is a process that has attracted much attention due to its high energy conversion efficiency. More recently, molybdenum (Mo)-based materials as electrocatalysts have been shown as the most effective HER, while their commercialization is obstructed by durability. Recently, MoS₂, (362) MoSe₂, (363) Mo₂C, (364) MoB, (365) MoS₂ analogues, (366) NiMoN_x, (367) Co_0.6Mo_1.4N₂, (368) Mo₂N, (369) and MoO₂ (370) have been employed as electrocatalysts for the HER in acidic/basic electrolytes; however, the durability of Mo-based catalysts is still not satisfactory in the presence of acidic or base electrolytes under the long-term or accelerated test. Chang et al. (371) employed the thermolysis of ammonium thiomolybdates in a CVD chamber to grow MoS_x on G-coated 3D Ni foams at various temperatures. Subsequently, the MoS_x/G/3D Ni foam electrode was used for electrocatalytic HER. According to their results, the G sheets on Ni foam gave the Ni protection against etching and increased the stability of working electrode in strong acid media. Additionally, these electrodes showed a large hydrogen production of ∼302 mL g^–1 cm^–2 h^–1 (13.47 mmol g^–1 cm^–2 h^–1) at an overpotential of V = 0.2 V and an improved current density of ∼45 mA cm^–2 at 0.2 V, due to the presence of bridging S₂^2– or apical S^2– in amorphous states. (371) Among the various types of Mo-based electrocatalysts, Mo₂C/G materials display remarkable HER activities and stability, including small overpotentials, large cathodic current densities, and high exchange current density under acidic and basic conditions. These properties are believed to be due to their unique d-band electronic structures (electronic structure like a noble metal). (372) Pan et al. (373) developed Mo₂C nanoparticles on GO sheets, and they found that the Mo₂C nanoparticles were stabilized by a carbon layer. The Mo₂C–rGO hybrid showed an overpotential voltage of ∼70 mV, and the cathodic current increased rapidly under more negative potentials. Notably, Mo₂C–rGO exhibited a large HER performance (mass activity ∼77 mA mg^–1 at 150 mV), a low Tafel slope (57.3 mV decade^–1), and good stability (stable after 1000 cycles (see Figure 65)). (373) The improved activity and stability were ascribed to the large surface area of the G support and the improved conductivity of the Mo₂C–RGO hybrid.

Figure 65. (a) HER polarization curves for catalysts, (b) Tafel plots, (c) stability test of Mo₂C–rGO hybrid, and (d) time dependence of current density of Mo₂C–rGO hybrid at an applied potential of 140 mV. Reprinted with permission from ref 373. Copyright 2014 Royal Society of Chemistry.

In a separate work, Xu et al. (370) employed the MoO₂/rGO hybrid as a highly efficient HER. They reported that the presence of oxygen-containing groups limits the growth of MoO₂ nanoparticles to a tiny size due to the space confinement effect between GO layers. The MoO₂/rGO hybrid display good HER activity with a low onset overpotential of 190 mV, a high cathodic current density, and a low Tafel slope (49 mV decade^–1) due to a synergistic effect between metallic MoO₂ nanoparticles and G with electronic communication promoted by an interface interaction. More recently, Zhang and co-workers (374) reported an amorphous MoS_xCl_y as a high-performance electrocatalyst for electrochemical hydrogen productions. These electrocatalysts showed large cathodic current densities and small Tafel slopes (∼50 mV decade^–1), which are attributed to the synergistic effects of a remarkable intrinsic activity of the MoS_xCl_y catalyst and a large active surface area. The recent work by Zhou et al. (375) on HER activity using N-doped carbon-wrapped Co nanoparticles with a size of ∼15 nm supported on N-doped G nanosheets (Co@NC/NG) is very interesting. The Co@NC/NG electrode exhibited a small overpotential (−49 mV) and small Tafel slope (79.3 mV decade^–1) due to carbon atoms promoted by the entrapped cobalt nanoparticles. It was found that the strong synergetic interaction between the G/GO and nanoparticles enhanced the charge separation and affected the band structure of G/GO. However, the properties of G/GO nanoparticle hybrids are usually ignored when G/GO is used as the electron acceptor and transporter. Furthermore, the defects in G/GO nanoparticles hybrids are essential for their electronic properties, and play a key role in improvement of the HER stability and activity of the supported catalysts. Accordingly, the structure defects of G/GO in G/GO–nanoparticle hybrids should be further researched, because they might be the active sites for hydrogen production. Moreover, the development of nonprecious catalysts with activities better than commercial Pt/C is still a big challenge for researchers who want to apply this technology in large-scale applications.

5.4 Green Chemistry and Environments

Noncovalently functionalized G/GO materials hold promise in the development of sustainable catalysts for green chemistry with low emissions and high selectivity. Therefore, the use of these materials in the growing field of “catalysis and environmental green chemistry” has become important due to their unique chemical properties, high mechanical resistance, and their favorable charge generation and transportation in catalysis and environmental processes. The G, GO, and its reduced oxide are necessary to disperse the materials in water for their application in the field of catalytic reaction and environmental pollution. (376) Achari et al. (377) developed highly aqueous dispersible aminoclay–rGO (AC–rGO) hybrids by the in situ condensation of aminoclay over GO followed by hydrazine reduction (see Figure 66). They found that these amphiphilic hybrid materials with high concentrations of 7.5 mg rGO/mL are stable in water solution and display simultaneous adsorption of Cyt-C via hydrophobic interaction and DNA via electrostatic interaction. In a separate study, McCoy and co-workers (378) employed noncovalent magnetic control to reversibly recover GO using iron oxide (Fe₂O₃) in the presence of magnetic surfactants. Because the GO is unchanged, there is no loss of its original properties; thus, the GO and magnetic material can be reused (see Figure 67a). Because of large differences in the isoelectric point of GO (pH ≈ 0) and Fe₂O₃ (pH ≈ 7), a wide gap is present in which the two materials show opposite surface charges (see Figure 67b), and thus the separation could be attributed to Coulombic attraction. The recyclable nature of this assembly and the large adsorption capacity of GO indicate the materials’ potential use in applications for decontamination and water treatment. (379) Zubir and co-workers (380) achieved efficient Acid Orange 7 (AO7) degradation using a GO–Fe₃O₄ hybrid. These enhancements were attributed to the synergistic effects between both optimized GO amount and Fe₃O₄ nanoparticles. This can be explained by several factors: First, the large surface area of exfoliated GO provides a uniform dispersion of Fe₃O₄ nanoparticles onto the surface of GO sheets, which is good for increasing the mass transfer of reactants toward the active (≡Fe²⁺/≡Fe³⁺) sites during the decontamination. (380) Second, GO has a large aromatic ring structure on its basal plane that supports AO7 adsorption via π–π interactions, which allows enhanced AO7 concentration within the active sites to be oxidized faster by the generated hydroxyl radicals (OH^•). (380) Third, the strong interaction between Fe₃O₄ NPs and GO through Fe–O–C bonds accelerates the electron transfer between the nanoparticles and GO sheets. (380) Finally, the synergistic effect between GO and Fe₃O₄ nanoparticles promotes the regeneration of ferrous irons to quicken the redox cycle on active sites, consequently enhancing the AO7 degradation and mineralization. (380) Liu et al. (381) synthesized halloysite nanotubes (HNTs) loaded on rGO sheets (abbreviated as HGC) via an electrostatic self-assembly process for removal of dyes from water. The electrostatic force occurred between the negative rGO sheets (van der Waals forces and hydrogen bonding) and HNTs positively charged by γ-aminopropyl triethoxysilane (APTES) functionalization. The rhodamine B (RhB) adsorption on HGC was ∼45.4 mg mg^–1 after seven cycles due to the big pore volumes, large surface area, the strong π–π stacking interactions, and its abundant functional groups on the surface. Le and co-workers (379) also developed a 3D microhydrogel of nanoparticle/G platelets by reversible self-assembly and aqueous exfoliation. These 3D hydrogels showed excellent methylene blue dye removal (adsorption capacity = 685 mg g^–1) and photocatalytic dye degradation due to the presence of large surface area (1677 m² g^–1), low band gap (1.8 eV), and good charge separation and rapid electron transfer. (379) Dong et al. (382) developed bioinspired surface functionalization of GO for dye and heavy metal ion adsorption. The poly dopamine (PD) functionalized GO (PD/GO) had superior Eschenmoser-containing dyes’ adsorption capacity up to 2.1 g g^–1. (382) Additionally, PD/GO also showed good adsorption capacity for heavy metal ions (53.6 mg g^–1 for Pb²⁺, 24.4 mg g^–1 for Cu²⁺, 33.3 mg g^–1 for Cd²⁺, and 15.2 mg g^–1 for Hg²⁺), suggesting it is a promising adsorbent for decontaminating wastewater. (382) Mondal and co-workers (383) developed a bifunctionalized G and expanded graphite using n-butyl lithium, and this material was then applied in efficient dye adsorption from dye contaminated water by noncovalent interaction between the dye and the COOH groups of the graphenic plane. In a recent report, Liang and co-workers (384) developed a facile and efficient electrostatic self-assembly strategy for improving the interfacial contact between rGO and MIL-53(Fe) (termed as M53–rGO). The M53–rGO hybrid displayed excellent photocatalytic activity (reduction of Cr(VI) rapidly increased to 100% under visible light illumination), which is attributed to a decrease in the recombination of photogenerated electron–hole pairs. It is believed that the good interfacial contact between MIL-53(Fe) and rGO facilitates the transfer of photogenerated electrons. These results open potential applications for the M53–rGO hybrid in industrial wastewater treatment.

Figure 66. Synthesis of AC–GO and AC–rGO hybrids. The blue platelets represent aminoclay, while the brown and gray sheets show GO and rGO, respectively. Reprinted with permission from ref 377. Copyright 2013 Royal Society of Chemistry.

Figure 67. (a) Schematic diagram of the basic concept of the experiment: proper pH is used to affect charge attraction/repulsion between the GO sheets and Fe₂O₃ nanoparticles. Fe₂O₃ nanoparticles separated from solution or dispersion by applied magnetic field. (b) Zeta potentials of GO and Fe₂O₃ nanoparticles. Reprinted with permission from ref 378. Copyright 2015 American Chemical Society.

G sheets have many advantages such as availability, solubility, high quality, environmentally friendly nature, and inexpensive, large-scale production; these benefits open an opportunity for exploring novel adsorption and degradation by synthesizing noncovalently functionalized G/GO hybrids. The existence of G/GO in the hybrid provides superior applications in different kinds of dyes adsorption/degradation from water due to the presence of large surface area, pore volume, and good active sites for chemical reactions.

5.5 Nano-Devices

Self-assembly and grafting of G/GO onto carbon fibers have been found to enhance the interfacial bonding with a shape memory polymer (SMP) matrix via van der Waals forces and covalent cross-link. (385) This effective approach remarkably improved the electrical properties and recovery performance of SMPs that are used for Joule heating triggered shape recovery at a lower electrical voltage. (386, 387) The electrical conductivity was further upgraded when nanoparticles were introduced into SMP composites because they reduce the gap between G/GO. With these scenarios in mind, it is evident that G/GO holds great promise for application in nanodevices. Basically, two mechanisms are involved in self-assembly of stable monolayers of alkane chain molecules on graphene: (388) (i) bonds between the G/GO and the molecular “anchor” group (many reports have been given on interactions of ammonia molecules with the surface of G/GO by monitoring charge transport in G field-effect devices as a function of gas exposure), (1, 389-392) and (ii) interchain interactions, for instance, van der Waals forces and hydrogen bonding. (393) Recently, Wang and co-workers (394) synthesized a polymer-functionalized rGO from a noncovalent functionalized pyrene-terminal polymer in benzoyl alcohol. They reported that these sheets exhibit organo-dispersibility, high grafting density, high electrical conductivity (see Figure 68), and good processability. Georgakilas et al. (170) prepared hydrophilic functionalized MWNTs and stabilized a large amount of pristine G sheets in water without the use of surfactants, ionic liquids, and hydrophilic polymers. The multidimensional (2D/1D) G/MWNTs composite exhibited a stable water dispersion at concentrations up to 15 mg mL^–1 and also was dispersible in other polar solvents. (170) Interestingly, these composites exhibited excellent conductivity (sheet resistance up to R_s ≈ 25 Ω □^–1 for free hybrid material and R_s ≈ 1300 Ω □^–1 for a polyvinilalcohol/hybrid composite film) after coating on paper by drop casting a dispersion of the water-soluble polymers. (170)

Figure 68. Conductivity of various hybrid materials of G/rGO. Reprinted with permission from ref 394. Copyright 2015 Royal Society of Chemistry.

In a separate study, Song et al. (94) developed epoxy–G hybrids with good thermal conductivity by using nonoxidized G flakes (GFs) through noncovalent functionalization. The noncovalently functionalized GFs, with 1-pyrenebutyric acid, stimulate dispersion of GFs in organic or aqueous solvents with high solubility and stability. The interfacial bonding between GFs and the polymer matrix was found to be responsible for the superior thermal conductivity enhancement. (94) Kozhemyakina and co-workers (395) achieved electronic communication between G and perylene bisimide via titration experiments, when both materials are either coated on a surface or dispersed in a homogeneous solution. This interaction is facilitated by the noncovalent binding of their conjugated π-systems. (395) The electronic properties of G can be tuned by modification with organic molecules; for example, dye molecules containing a conjugated π-system can be utilized to change the electronic structure of G. In this vein, Parvez and co-workers (396) have fabricated organic field-effect transistors on G sheets. The highly conductive (sheet resistance ∼4.8 kΩ □^–1) G sheets were achieved in high quality and high yield (>80%) by electrochemical exfoliation of graphite. They also reported that the G had a large sheet size, low oxygen content, and/or high C/O ratio as well as good electronic properties. (396) Noncovalent functionalization of G by van der Waals forces provides another method for fabrication of electronic devices as it does not induce severe changes into G. For example, Woszczyna et al. (397) and Nottbohm et al. (398) developed a simple approach to such functionalization by using mechanical stacking of an amino-terminated carbon nanomembrane (NH₂-CNM) and single-layer G (SLG) sheets. The electric transport performances of these bare G and heterostructure (H) electric field devices are displayed in Figure 69. Raman mapping of D, G, and 2D peaks (see Figure 69b) exhibits the materials’ excellent structural quality and homogeneity on a large scale, which is further confirmed by electric transport measurements (see Figure 69c–g). They found that the intrinsic electronic quality of pristine SLG sheets is preserved in the heterostructures, thereby opening many possibilities for the use of G-based electronic in nanodevices. Halik et al. (399) reported a simple approach to fabricate oxo-functionalized graphene/polymer composite for low-voltage operating memory devices.These devices can be operated at 3 V. They also found that the thin film coating (∼5 nm) is mandatory to make the memory device function at low voltage. Additionally, a self-assembled monolayer of an imidazolium derivative further improves the function of the memory device.

Various types of molecules have been connected to G/GO through π–π stacking, and interfacial interactions between molecules and epoxy groups have been increased; this, in turn, has led to improvements in electrical and thermal conductivity. (1, 94, 170, 385-395) However, this approach requires a further investigation and progress because of some serious limitations in industrial level application such as the high costs of organic/inorganic derivatives and time-consuming, tedious synthesis.

Figure 69. Electric transport calibrations of G and heterostructure (H) electric field devices. (a) Optical microscope image of the H-device. (b) Raman mapping of 2D, G, and D peaks. (c) G resistivity at various position contacts (P1–P4) versus back-gate voltage (U_BG) at room temperature.(d) Electric charge mobility of G in H- and G-devices versus carrier concentration (n) at room temperature.(e) The electric charge mobility in H- and G-devices at n = −2 × 10¹² cm^–2. (f) Conductivity of G in H3 and G1 in the vicinity of their charge neutrality points at room temperature. (g) Electrons and holes coexistence represented by Hall coefficient calibrations for devices H3 and G1 at a magnetic field of 1 T and a temperature of 250 mK. Dashed lines showed the single-particle model for holes and electrons. Reprinted with permission from ref 397. Copyright 2014 Wiley-VCH.

5.6 Catalysis and Photocatalysis

Noncovalent functionalization of G/GO with nanoparticles may lead to light harvesting and charge transfer features. In these materials, the lattice structure of G/GO remains intact and exhibits most of its intrinsic electronic properties. Thus, the hybrid materials of G/GO with nanoparticles bear great potential for catalysis and large-scale energy storage conversion applications, particularly when photo- and redox active chromophores, such as porphyrins or phthalocyanines, are involved in the graphite exfoliation and G stabilization. Recent studies on zinc(II) alkylsulfonylphthalocyanine–pyrene conjugate (ZPC) with highly exfoliated graphite and their photophysical properties reported by Roth et al. (400) are intriguing. In their report, the authors showed that ZPC stabilizes single layer G during the ultrasonication of graphite by virtue of strong electronic interactions of the hybrid in both the ground and the excited states. The presence of the pyrene functional group in the conjugate is crucial in respect of noncovalently immobilizing the electron accepting phthalocyanines onto the basal plane of graphite. (400) Wang et al. (401) developed a 3D mesoporous Fe₃O₄@Cu₂O–GO framework as an efficient and recyclable catalyst for the synthesis of quinoxalines by using different substituents, that is, electron-rich and electron-withdrawing groups o-phenylenediamine and terminal alkyne, respectively. This 3D mesoporous framework exhibited good catalytic activity, selectivity (>99%), and recyclability after nine cycles, and this is believed to be due to its large surface area, large pore volume, unique structure, impressive mass transport, and application of an external magnetic field. (401) Further catalytic activity can be enhanced by increasing the active surface area of hybrid catalysts, that is, reducing the nanoparticle size (<2 nm). However, reducing the size of particles to less than 2 nm is limited by the conventional methods that utilize templates such as surfactants or dendrimers, which unfortunately can form barriers that confine the catalytic activity. Ren and co-workers (402) created a new catalyst containing 1–2 nm Au nanoparticles (NPs) anchored to thiophenol functionalized G sheets (Au/TGS). The Au/TGS catalysts exhibited better catalytic activity for the reduction of 4-nitrophenol because of the synergistic effects between the TGS and Au NPs and the high utilization of the metal catalyst. Besides catalytic reactions, many efforts have been made to enhance the photocatalytic activity of G/GO and nanoparticle hybrid materials. (403-406) Joseph and co-workers (407) fabricated a π–π stacked anchored by squaraine dye (VJ-S) sensitized r-NGOT (hybridized r-NGO and TiO₂ in a self-assembled core/shell structure (VJ-S/r-NGOT)) material and evaluated its photocatalytic activity and H₂ evolution performance. The direct charge transfer and π–π interaction between VJ-S and r-NGOT occurred due to the presence of an electron-deficient center in the VJ-S. The VJ-S/r-NGOT displayed better photocatalytic production of hydrogen (apparent photonic efficiency = 0.91%) under visible light because VJ-S dye absorbs visible and near IR (NIR) wavelengths and gives a direct energy transfer to r-NGOT. (407) Ma and co-workers (408) enhanced the short circuit current and energy conversion of an DSSC by 35.8% and 26.8%, by incorporating activated G nanoplatelets (a-GNPs, 0.02 wt %) into a TiO₂ film photoanode (see Figure 70). They also reported that an appropriate a-GNPs amount and a 3D nanostructure act as an efficient pathway for electrolyte ions and electrons, facilitating the rapid electron transfer and charge separation and suppressing the electron recombination and back transport reaction in DSSCs. (408)

Figure 70. Photovoltaic and impedance performances of the DSSCs with different G/TiO₂ photoanodes. Reprinted with permission from ref 408. Copyright 2015 Royal Society of Chemistry.

Xu et al. (409) reported in a theoretical study the effect of O atoms on photocatalytic hydrogen evolution in g-C₃N₄ and rGO sheets hybrid materials. Interestingly, they showed that the O concentration changes the direct-gap hybrid to an indirect-gap one. Moreover, they showed that the interfaces in g-C₃N₄/rGO-3 and g-C₃N₄/rGO-4 hybrids are type-II heterojunction, and negatively charged O atoms in the rGO are active sites, which lead to high-efficiency photocatalytic generation of hydrogen (see Figure 71). (409) Another experiment reported that rGO does not affect the charge separation process but drastically increases the lifetime of photogenerated charge carriers. (410) In a recent study, Feifel and co-workers (411) developed a very simple way to generate a high photocurrent by using the photosystem I (PSI) on artificial interfaces of π-system-modified G electrodes. They concluded that the improved photocatalytic activity of the π-system-modified G electrodes could be attributed to the surface property adaptation and the excellent conductivity of G. The main benefit of coupling PSI to the modified G by covalent binding is reflected by the light-power dependency study, which shows a distinctly good current conversion under the light. (411) Moon et al. (412) systematically explored the interaction of rGO and TiO₂ for efficient solar production of H₂O₂. They reported not only an organic-electron-donor-free, but also a noble-metal-free TiO₂-based photocatalytic system for the production of H₂O₂ up to a millimolar level, and interestingly in situ formation of cobalt phosphate was achieved on the rGO/TiO₂ hybrid. Lee et al. (413) developed a 3D monolayer G and TiO₂ assembly for high-efficiency electrochemical photovoltaic cells. A 3D nanostructure with high carrier mobility gives a direct pathway for electrons to the current collector electrode for a photoanode in DSSCs. The energy conversion efficiency of DSSC was increased by ∼10% under the optimized 3D hybrid structure, and this is due to improved light harvesting and reduced electron recombination at the photoanode. (413) Despite the excellent progress in higher catalytic and photocatalytic activity, these materials usually exhibit low selectivity to desired products or a high deactivation rate due to the gradual migration and agglomeration of the active phase during the reaction. In addition, most catalysts and/or photocatalysts reported so far are recovered by tedious filtration or centrifugation. Thus, methods toward the design and synthesis of more efficient catalytic or photocatalytic systems remain a challenge.

Figure 71. General mechanism for H₂ evolution from photocatalytic water splitting by the g-C₃N₄/rGO-3 hybrid, in which g-C₃N₄ acts as an electron sink providing the separation of electron–hole pairs and collects the electrons injected from the photoexcited rGO-3 for subsequent H₂ production from reduction of H₂O. Reprinted with permission from ref 409. Copyright 2015 American Chemical Society.

5.7 Biosensors and Bioimaging

Several studies have utilized noncovalently functionalized G/GO in biological applications, ranging from biosensing (human telomerase detection, disease-related diagnostics) to cell-imaging. (414-418) Gu and co-workers (419) developed a superparamagnetic functionalized G/Fe₃O₄@Au hybrid for a magnetically controlled solid-state electrochemiluminescence biosensing. They found that the hybrid exhibited high sensitivity for HeLa cells with a linear range of 1–20 × 10⁴ cells/mL, long-term stability, high emission intensity, high reproducibility, excellent electron transfer, and superparamagnetic behavior. To directly sense atropine in complex matrixes, Bagheri and co-workers (420) advanced the field by developing Co₃O₄–G-modified carbon paste electrodes for selective detection of atropine in biological fluids, that is, urine and human serum. They reported that the recovery of spiked atropine in biological samples displayed standard values in the range from 97.6% to 103.2%, indicating the successive applicability of the proposed strategy for real clinical applications. In a recent report, Yoon and co-workers (421) utilized a noncovalently functionalized GO sheet on a patterned Au surface to isolate circulating tumor cells (CTCs) from blood samples of pancreatic, breast, and lung cancer patients. The noncovalently functionalized GO/Au showed excellent sensitivity toward capture of CTC, even at very low concentrations of target cells (see Figure 72); the principle of capture was explained in terms of morphological features of Au surfaces. (421)

Figure 72. Capture of circulating tumor cells (CTCs) from breast cancer: (a) patient no. 6 (Br6); (b) patient no. 2 (Br2); and (c) quantification of CTCs. Capture of CTC from pancreatic cancer: (d) patient no. 2 (Pan2); (e) patient no. 9 (Pan9); and (f) quantification of CTCs. Capture of CTC from lung cancer: (g) patient no. 3 (L3); (h) quantification of CTCs; and (i) gene expression of captured CTCs via qRT-PCR. Reprinted with permission from ref 421. Copyright 2013 Nature Publishing Group.

In another study, a novel, all-electronic biosensor for the identification and quantification of opioids was developed by Lerner and co-workers. (422) It consists of an engineered μ-opioid receptor protein, with high binding affinity for opioids, which is chemically bonded to a G field-effect transistor to read out ligand binding. These G-based field-effect transistors are able to sense the opioid receptor antagonist naltrexone at ultralow concentrations (10 pg mL^–1). Recently, Singh et al. (423) developed a noncovalently functionalized single layer G for sensitivity enhancement of surface plasmon resonance (SPR) immunosensors. There are two main goals for this approach: (i) amplification of the SPR signal through G, and (ii) control of the immobilization of biotinylated cholera toxin antigen on the copper coordinated nitrilotriacetic acid (NTA) functionalized G as a single layer (the NTA was attached on G via pyrene derivatives through π–π interactions). (423) With this experimental setup, they reported the very low detection limit of 4 pg mL^–1 for the anticholera toxin specific antibody. (423) Because of the many advantages (i.e., label-free, real-time, and high-throughput) of SPR imaging (SPRi) techniques for immunoassays, it is frequently used in sensors, but this method suffers from unfavorable detection limits. In this regard, Hu et al. (424) developed a dual signal amplification strategy utilizing polydopamine (PDA) functionalization of rGO (PDA–rGO) sheets for detection of biomarkers. The PDA–rGO-based devices exhibited detection limits for model biomarker of 500 pg mL^–1 on an ultralow fouling SPRi chip over a wide range of conditions (see Figure 73). (424) Moreover, if HAuCl₄ solution was allowed to flow through the chip surface for the second signal amplification, the SPRi signals on sensing spots drastically increased due to the growth of gold nanostructures on the captured PDA–rGO sheets, while on the control spots where no PDA–rGO was captured, the SPRi signal changes remained negligible (see Figure 73e,f). This implies that flowing HAuCl₄ solution on the polymer brush-modified SPRi gold chip without precaptured PDA–rGO sheets does not lead to significant SPRi response; it is hypothesized that the densely packed polymer chains are able to efficiently prevent the HAuCl₄ from accessing the gold chip and, hence, the deposit does not interfere with the signal amplification. The observed behavior was explained in terms of a high mass-density and dielectric constant of the gold nanostructures and the electromagnetic coupling between the gold nanostructures and the underlying gold thin film. Thus, as the deposition of gold exclusively takes place on PDA–rGO sheets, the SPRi signals stemming from the immunoassay were further efficiently and specifically enhanced by the second signal amplification, and the signal-to-noise ratio for the immunoassay was remarkably increased, securing improved performance. (424)

Figure 73. SPRi sensing profiles, differential images, and line profiles for detection in human serum: (a,b) Direct detection, (c,d) antibody-conjugated PDA–rGO for signal amplification, and (e,f) sequential Au coated. The red color line in panels (a), (c), and (e) displayed the results on the sensing point, and the black lines are collected from the control point. The blue boundaries in (b), (d), and (f) showed the four sensing points on the SPRi chip. Reprinted with permission from ref 424. Copyright 2014 American Chemical Society.

In a separate study, Yi and co-workers (425) employed the advanced aptamer-two-photon dye (TPdye)/GO TPE (two-photon excitation) fluorescent nanosensing conjugate for in vitro or in vivo molecular probing in biological fluids, living cells, and zebrafish. They reported that the GO/aptamer–TPdye approach was a robust, sensitive, and selective sensor for quantitative detection of adenosine triphosphate (ATP) under the complex biological system with fast delivery into live cells or tissues and succeeded as a “signal-on” in vivo sensor for specific detection of target biomolecules. (425) Castrignano and co-workers (426) developed a drug screening based on human flavin-containing monooxygenase 3 (hFMO3 is the isoform present in the adult liver) immobilized on GO. The electrochemical property of hFMO3 was improved by GO in terms of electron transfer rate, current signal-to-noise ratio, and apparent surface coverage. Thus, this electrode showed good drug screening by N-oxidation of two therapeutic drugs, such as benzydamine and tamoxifen. (427) Koninti et al. (162) developed a GO-based molecular switching of ellipticine (E) to monitor the loading of anticancer drug onto GO and its release to DNA/RNA through direct optical detection. Formations of 3D assemblies involving GO and biomolecules by noncovalent interactions are responsible for biomolecule(s)-assisted fluorescence-switching of E. In another study, Xu and co-workers (427) synthesized G/Cu nanoparticle hybrids (G/CuNPs) as a surface-enhanced Raman scattering (SERS) substrate for adenosine detection by means of chemical vapor deposition in the presence of methane and hydrogen. This hybrid exhibited a remarkable SERS improvement activity for adenosine (detected concentration in serum ∼5 nM). On the basis of the above discussion, they found that the noncovalently functionalized G/GO can be used in the detection and imaging of biomolecules. These results open these materials to future applications in medicine and biotechnology. Another example of sensing application is the use of GO/CDs hybrid for the selective labeling of cell cytoplasm. (428) Here, GO would act as a substrate for immobilization of quaternary ammonium modified carbon dots, thus enabling the preferential labeling of the cell cytoplasm while pristine carbon dots penetrate as fluorescent markers to the cell nucleus (see Figure 74). (428)

Figure 74. Fluorescence images of mouse fibroblast NIH/3T3 cells containing (a) CDs and (b,c) GO/CDs hybrids, demonstrating selective labeling of nuclei and cytoplasm. For pure carbon dots, a fast endocytosis occurred, and carbon dots readily entered cell nuclei (panel (a)). However, if GO/CDs hybrids were employed, penetration into cells was gradually inhibited upon increasing GO concentration (panels (b) and (c)). Reprinted with permission from ref 428. Copyright 2014 Royal Society of Chemistry.

5.8 Biotherapeutics

There have been more concerns in medicine about fundamental approaches to deliver small molecule drugs/nucleotides/peptides to specific tissues. (429) In this context, several studies have utilized G/GO in the delivery of chemotherapeutics for the treatment of cancer for a host of medical conditions, NIR phototherapy, and even for the stem cells proliferation and differentiation on G/GO surface. (159, 430-433) In this way, small-size GO (small-GO) sheets show high NIR light absorbance and biocompatibility for potential photothermal therapy. (434) Moreover, GO displays excellent photothermal agent properties due to its nanosize, high photothermal efficiency, and low price as compared to other NIR photothermal agents such as gold particles and carbon nanotubes, etc. Figure 75 shows the effect of transdermal nano GO–hyaluronic acid (NGO–HA) conjugates for photothermal ablation therapy of melanoma skin cancer using a NIR laser. (435) In this hybrid, HA works as a transdermal delivery carrier of chemical drugs and biopharmaceuticals. Jung et al. (435) reported the photothermal ablation therapy of skin cancer by using the NGO and NGO–HA in SKH-1 mice inoculated with B16F1 cells on both dorsal flanks. The treatment NGO–HA showed that tumor tissues were completely ablated by the photothermal therapy with NIR irradiation (see Figure 76c). They also noticed that there was no recurrence of tumorigenesis in comparison to gradual tumor regrowth after photoablation applied to tumor tissues. On the other hand, PBS and NGO displayed no significant tumor ablation effect regardless of NIR irradiation (see Figure 76a,b). (435) The better transdermal delivery was observed for NGO–HA hybrid to tumor tissues in the skin of mice. This may be due to highly expressed HA receptors and relatively leaky structures around tumor tissues, enabling the increased permeation and retention of nanoparticles.

Figure 75. Schematic diagram for the transdermal delivery of nano GO–hyaluronic acid conjugates into melanoma skin cancer cells under a NIR laser. Reprinted with permission from ref 435. Copyright 2014 American Chemical Society.

Figure 76. Pictures showing the effect of photothermal ablation therapy using NIR irradiation on the tumor growth in mice inoculated with B16F1 cells on both dorsal flanks after topical administration of (a) PBS, (b) NGO, and (c) NGO–HA. (d) Day-dependent relative tumor volume. (e) Time-dependent caspase-3 activity in tumor tissues to evaluate the heat-induced apoptosis (***P < 0.0001). Reprinted with permission from ref 435. Copyright 2014 American Chemical Society.

For gene delivery, many reduction-sensitive biodegradable cationic polymers, which contain disulfide linkages, have been designed. (436) These materials degrade inside cells due to high concentrations of glutathione in the cytosol, which may reduce cytotoxicity and enhance transfection efficiency by avoiding accumulation of high-molecular-weight polycations and facilitating rapid release of DNA into cells. (436, 437) Recently, Yang et al. (438) introduced atom transfer radical polymerization (ATRP) initiation sites containing disulfide bonds onto surfaces of GO. They then modified the GO by ATRP with (2-dimethyl amino) ethyl methacrylate (DMAEMA) and synthesized a series of organic–inorganic composites (abbreviated as SS–GPDs) for efficient gene delivery (see Figure 77). They also showed that the SS–GPD materials can attach and absorb aromatic, water-insoluble drugs, such as CPT, for effective killing of cancer cells due to the conjugated structure of the GO basal plane. (438) In summary, they were able to design a new class of gene/drug delivery systems by tuning the attached polycation side chains on GO surfaces in the presence of ATRP.

Figure 77. Schematic diagram for fabrication of biocleavable PDMAEMA–GO sheets by ATRP for gene/drug delivery. Reprinted with permission from ref 438. Copyright 2014 Royal Society of Chemistry.

Noncovalently functionalized G/GO nanomaterials hold potential applications in the field of drug delivery due to their six-membered carbon ring structure, which can allow π–π interactions and hydrophobic interactions with aromatic rings of drugs. (159, 439) Additionally, glutathione (GSH) can also induce drug release caused by the disruption of noncovalent hydrophobic interactions and π–π stacking of GO aromatic rings. (440) In the case of nucleus drug delivery, a drug-loaded GO should be able to escape from the endosome after endocytosis-mediated cellular uptake followed by the discharge of the drug from the carrier during the formation of the drug–proteasome hybrid. (441) The endosomal escape due to photothermally induced heat is possible, and the drug can also be released by GSH in the presence of NIR irradiation. (442) Kim and co-workers (443) developed a nanosized PEG–BPEI–rGO composite consisting of rGO sheets covalently conjugated with branched polyethylenimine (BPEI) and polyethylene glycol (PEG). The water-stable PEG–BPEI–rGO could deposit a larger amount of doxorubicin (DOX) than unreduced PEG–BPEI–GO through π–π and hydrophobic interactions. (443) Subsequently, the PEG–BPEI–rGO/DOX complex was tested for the photothermal effect by NIR irradiation in both test tubes and cells. Interestingly, they found that this hybrid could escape from endosomes after cellular uptake by photothermally induced endosomal disruption and the proton sponge effect, followed by GSH-induced DOX release into the cytosol. (443) Yan et al. (444) developed a smart G hybrid with singlet oxygen for the photodynamic treatment of cancer cells. They reported that GO can act as a singlet oxygen generation (SOG) controller, which can reversibly quench and recover SOG again after introducing a target molecule. This recovery relies on the interaction intensity between GO and a photosensitizer. They also found that this complex worked as a carrier for larger loading and delivery of the photosensitizers to cancer cells. (444) More recently, Dong and co-workers (445) conducted a specific-gene-targeting agent delivery for improved therapeutics by utilizing a multifunctional hybrid of poly(l-lactide) (PLA) and polyethylene glycol (PEG)-grafted GQDs (f-GQDs). PEG and PLA in noncovalent functionalization of GQDs can enhance the super physiological stability and durable photoluminescence over a wide range of pH values, which is utilized for cell imaging. (445) These hybrids also showed improved biocompatibility and lower cytotoxicity. The targeting miRNA-21 agents were adsorbed on the high surface area of GQDs. Combined conjugation of miRNA-21-targeting and surviving-targeting agents displayed excellent inhibition of cancer cell growth and more apoptosis of cancer cells; this suggests that noncovalent functionalization of GQDs can be utilized in biomedical application of intracellular molecular analysis and clinical gene therapeutics. Although noncovalently functionalized G/GO offers many possible applications in the biomedical field, it demonstrated high toxicity, which is one of the biggest drawbacks that limits its applications in humans. (446) For this reason, further research is required to overcome this limitation.

6 Conclusions and Challenges

ARTICLE SECTIONS

Jump To

Noncovalent functionalization involving mainly π–π interactions, van der Waals forces, hydrogen bonding, ionic interactions, or electron donor–acceptor complexes represents the strategic way to control the properties and improve the performance of G and GO in various advanced applications. In recent years, huge progress was registered in terms of theoretical description and experimental observation of interaction modes and morphological arrangements of various species onto G/GO surface also due to the unique contributions of ultrahigh vacuum scanning tunneling microscopy (STM). The STM description of the molecule assembly onto the G/GO substrate is still limited by the planarity and size of the studied molecules. From this point of view, the possibility to observe the interactions, conformations, and transformations of various larger molecules and biomolecules onto G/GO is still a big challenge with the possible principal impact in many sensing and biomedical applications. Another challenge is to increase the yield and quality of single-layer G produced by the chemical exfoliation of graphite in various organic solvents where π–π interactions constitute the main driving force.

A challenging issue is also to create Janus-like G composed of two different π–π stacked molecules on either side of the sheet (e.g., electron-donating and -withdrawing molecules) to tailor its electronic properties. Still, the noncovalent approaches possess limited success in the band gap control of G as compared to covalent routes starting from G, GO, or fluorographene and resulting in many new derivatives with variously opened band gaps. Similarly, neither G nor its derivatives exhibit self-sustainable magnetism despite many reported attempts to induce sp-based magnetism at room temperature. With this respect, the noncovalent functionalization of G/GO with magnetic nanoparticles (mainly iron oxides) provides an easy way to create a magnetically controllable system for delivery and separations in biomedicine or environmental applications. The use of suitable molecular species (molecular magnets) would be, in our opinion, another alternative with an advantage of the preservation of a 2D character of the magnetic hybrid.

Among tens of possible functionalization species, polymers play an important role mainly in noncovalent modification of G enhancing its hydrophilicity and biocompatibility. In the case of GO being hydrophilic due to the oxygen-bearing functional groups, the polymer functionalization brings an enhanced colloidal stability and suitable functional groups for further advanced nanoarchitecture for applications, for example, in targeted drug and gene delivery. Another interesting example of noncovalent functionalization is the creation of hybrids combining G/GO with other carbon nanoallotropes or G analogues. For example, the modification of G with OH-functionalized MWCTs resulted in a highly conductive and hydrophilic hybrid with a huge potential in the fields of conductive inks for inkjet printing or highly conductive polymers. The hybrids of G with other 2D analogues (e.g., MoS₂ or WS₂) create unique nanodevices acting as advanced biosensors, photoinduced memory device, Li-ion batteries, or field-effect transistors.

In the field of energy materials, the hybrids of G/GO with TiO₂ also have a strong position with many reported applications in LIBs and mainly in dye-sensitized solar cells. Such hybrid photoanode materials would exhibit higher efficiency as compared to pristine TiO₂ as G accelerates the electron transfer and decreases the charge recombination. However, the energy conversion improvement based on these hybrid materials is still a challenge mainly in terms of recent developments of perovskite-based solar cells.

Quantum dots (QD) are another important group of the nanomaterials discussed in this Review and commonly used for noncovalent modification of G/GO. These hybrids exhibit an excellent efficiency in many fields involving photocatalysis, supercapacitance, LIBs and NIBs, photoelectrochemical splitting of water, photosensitizers, water purification, biosensing, cell labeling, and catalysis. For example, QD/G hybrids have been extensively applied in photoelectrochemical solar cells with the added values based on transparency and conductivity of G materials as compared to traditionally applied electrodes. Importantly, noncovalent attachment is beneficial to ensure enhanced phototransfer processes between QD and G surface. Despite many applications of QD/G(GO) hybrids in various fields, there are still just a few reported applications in biomedicine. Here, the hybrids of biocompatible carbon dots with GO would play the principal role in the future as proved by recent application of such a hybrid for selective labeling of cell cytoplasm. Finally, metals and metal oxides noncovalently attached onto G/GO surface are today very promising mainly in the field of catalysis, separable catalysts, and electrochemical applications. In these applications, the G/GO substrate helps to control the homogeneous distribution and size of nanoparticles with improved reaction yields, selectivity, or recyclability of the catalyst. However, the aspects of the nanocatalyst release and leaching into the environments should be carefully addressed.

Author Information

ARTICLE SECTIONS

Jump To

Corresponding Authors
- Kwang S. Kim - Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea; Email: [email protected]
- Radek Zboril - Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 Listopadu 1192/12, 771 46 Olomouc, Czech Republic; Email: [email protected]
Authors
- Vasilios Georgakilas - Material Science Department, University of Patras, 26504 Rio Patras, Greece
- Jitendra N. Tiwari - Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea
- K. Christian Kemp - Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea
- Jason A. Perman - Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 Listopadu 1192/12, 771 46 Olomouc, Czech Republic
- Athanasios B. Bourlinos - Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 Listopadu 1192/12, 771 46 Olomouc, Czech Republic
Notes
The authors declare no competing financial interest.

Biographies

ARTICLE SECTIONS

Jump To

Vasilios Georgakilas

Download MS PowerPoint Slide

Vasilios Georgakilas received his B.Sc. and Ph.D. degrees in Chemistry and Organic Chemistry from the University of Ioannina (Greece) in 1989 and 1998, respectively. He then worked in the Institute of Material Science of N.C.S.R. “Demokritos”, Greece, and at the University of Trieste, Italy, as a Postdoctoral Fellow and Research Associate. He currently holds the position of Assistant Professor at the Material Science Department, University of Patras, Greece. His research interests lie in the synthesis and organic functionalization of nanostructured materials, with a particular emphasis on carbon nanomaterials and their applications.

Jitendra N. Tiwari

Download MS PowerPoint Slide

Jitendra N. Tiwari received his Ph.D. degree in Electrochemistry from the Department of Materials Science and Engineering, National Chiao Tung University, Taiwan, in 2009, working on the synthesis of highly durable catalysts for electrochemical energy devices. He worked as postdoctoral research fellows at the Institute of Nanotechnology, National Chiao Tung University, Taiwan, and also at the Department of Chemistry, Pohang University of Science and Technology. Currently, he is a senior research scientist at the Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), and his work focuses on the development of graphene-based hybrid materials, and their applications in energy storage and conversion.

K. Christian Kemp

Download MS PowerPoint Slide

K. Christian Kemp received his Ph.D. in Chemistry at the Department of Chemistry, Pohang University of Science and Technology, under the guidance of Professor Kwang S. Kim. He is currently pursuing postdoctoral research at the Center for Ordered Nanoporous Materials Synthesis at Pohang University of Science and Technology. His interests include nanomaterials, catalysis, and organometallics for environmental applications.

Jason A. Perman

Download MS PowerPoint Slide

In 2013, Jason A. Perman joined the Research Centre of Advanced Technologies and Materials at the Palacky University in Olomouc, Czech Republic, as a Junior Researcher. He was born in Tampa, FL, in 1983 and received his B.Sc. (2006) and Ph.D. (2011) degrees from the University of South Florida under the supervision of Professor Michael J. Zaworotko in the field of supramolecular chemistry. He was a postdoctoral associate with Professor Josef Michl from 2011–2013 at the Institute of Organic and Biochemistry, Academy of Science of the Czech Republic. His current research interests include supramolecular chemistry, green chemistry, Langmuir films, metal–organic materials, and materials based on graphene and graphene oxide.

Athanasios B. Bourlinos

Download MS PowerPoint Slide

Athanasios B. Bourlinos holds B.Sc. (1991–1995), M.Sc. (1997–1999), and Ph.D. (1999–2002) degrees in Chemistry from Athens University, Greece. He spent 2 years (2002–2004) as a postdoctoral fellow at the Materials Science & Engineering Department, Cornell University (Ithaca, NY), 6 years (2005–2011) as a research associate at the Institute of Materials Science, NCSR “Demokritos” (Athens, Greece), and 1 year (2011–2012) as a research associate at the Physics Department, University of Ioannina (Ioannina, Greece). He currently holds a position as Assistant Professor at the Physics Department, University of Ioannina. His research area focuses on the synthesis or surface modification, characterization, and properties of nanoscale materials with emphasis on carbon nanostructures.

Kwang S. Kim

Download MS PowerPoint Slide

Kwang S. Kim received his Ph.D. degree from University of California, Berkeley. He was a postdoctoral fellow at IBM and a visiting professor or scientist at Rutgers University, MIT, and Columbia University. He was a professor in the Department of Chemistry, Pohang University of Science and Technology. Currently, he is a distinguished professor in the Department of Chemistry and the director of the Center for Superfunctional Materials at Ulsan National Institute of Science and Technology (UNIST). His research interest includes molecular sensing, nanomaterials, and molecular devices.

Radek Zboril

Download MS PowerPoint Slide

Radek Zboril received his Ph.D. degree at the Palacky University in Olomouc, Czech Republic. After his doctoral studies, he spent a lot of time at universities around the world in locations such as Tokyo, Delaware, and Johannesburg. Currently, he is a professor at the Department of Physical Chemistry and a General Director of the Regional Centre of Advanced Technologies and Materials at the Palacky University in Olomouc, Czech Republic. His research interests focus on nanomaterial research including iron- and iron oxide-based nanoparticles, silver nanoparticles, carbon nanostructures, and magnetic nanoparticles, their synthesis, physicochemical characterization, and applications in catalysis, water treatment, antimicrobial treatment, medicine, and biotechnology.

Acknowledgment

ARTICLE SECTIONS

Jump To

We acknowledge support from the Ministry of Education, Youth and Sports of the Czech Republic (LO1305). K.S.K. acknowledges the support from Korean NRF (National Honor Scientist Program: 2010-0020414).

References

ARTICLE SECTIONS

Jump To

This article references 446 other publications.

1
Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A. Electric Field Effect in Atomically Thin Carbon Films Science 2004, 306, 666– 669 DOI: 10.1126/science.1102896

Google Scholar

1
Electric Field Effect in Atomically Thin Carbon Films

Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A.

Science (Washington, DC, United States) (2004), 306 (5696), 666-669CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

The authors describe monocryst. graphitic films, which are a few atoms thick but are nonetheless stable under ambient conditions, metallic, and of remarkably high quality. The films are a two-dimensional semimetal with a tiny overlap between valence and conductance bands, and they exhibit a strong ambipolar elec. field effect such that electrons and holes in concns. up to 1013 per square centimeter and with room-temp. mobilities of ∼10,000 square centimeters per V-second can be induced by applying gate voltage.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXos1Kqt70%253D&md5=488da13500bf24e8fc419052dc1a9e84
2
Balandin, A. A.; Ghosh, S.; Bao, W.; Calizo, I.; Teweldebrhan, D.; Miao, F.; Lau, C. N. Superior Thermal Conductivity of Single-Layer Graphene Nano Lett. 2008, 8, 902– 907 DOI: 10.1021/nl0731872

Google Scholar

2
Superior Thermal Conductivity of Single-Layer Graphene

Balandin, Alexander A.; Ghosh, Suchismita; Bao, Wenzhong; Calizo, Irene; Teweldebrhan, Desalegne; Miao, Feng; Lau, Chun Ning

Nano Letters (2008), 8 (3), 902-907CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

The authors report the measurement of the thermal cond. of a suspended single-layer graphene. The room temp. values of the thermal cond. in the range ∼(4.84 ± 0.44) × 103 to (5.30 ± 0.48) × 103 W/mK were extd. for a single-layer graphene from the dependence of the Raman G peak frequency on the excitation laser power and independently measured G peak temp. coeff. The extremely high value of the thermal cond. suggests that graphene can outperform carbon nanotubes in heat conduction. The superb thermal conduction property of graphene is beneficial for the proposed electronic applications and establishes graphene as an excellent material for thermal management.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXitFegsL4%253D&md5=27fd78ea971fa75db071450655dd7f68
3
Lee, C.; Wei, X.; Kysar, J. W.; Hone, J. Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene Science 2008, 321, 385– 388 DOI: 10.1126/science.1157996

Google Scholar

3
Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene

Lee, Changgu; Wei, Xiaoding; Kysar, Jeffrey W.; Hone, James

Science (Washington, DC, United States) (2008), 321 (5887), 385-388CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an at. force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per m (N m-1) and -690 N m-1, resp. The breaking strength is 42 N m-1 and represents the intrinsic strength of a defect-free sheet. These quantities correspond to a Young's modulus of E = 1.0 terapascals, third-order elastic stiffness of D = -2.0 terapascals, and intrinsic strength of σint = 130 gigapascals for bulk graphite. These expts. establish graphene as the strongest material ever measured, and show that atomically perfect nanoscale materials can be mech. tested to deformations well beyond the linear regime.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXosVOrs7k%253D&md5=c85babfb5827a1ce93f7e9673a4c8b86
4
Schafhaeutl, C. Ueber die Verbindungen des Kohlenstoffes mit Silicium, Eisen und anderen Metallen, welche die verschiedenen Gallungen von Roheisen, Stahl und Schmiedeeisen bilden J. Prakt. Chem. 1840, 21, 129– 157 DOI: 10.1002/prac.18400210117

Google Scholar

There is no corresponding record for this reference.
5
Bernal, J. D. The Structure of Graphite Proc. R. Soc. London, Ser. A 1924, 106, 749– 773 DOI: 10.1098/rspa.1924.0101

Google Scholar

There is no corresponding record for this reference.
6
Wallace, P. R. The Band Theory of Graphite Phys. Rev. 1947, 71, 622– 634 DOI: 10.1103/PhysRev.71.622

Google Scholar

6
The band theory of graphite

Wallace, P. R.

Physical Review (1947), 71 (), 622-34CODEN: PHRVAO; ISSN:0031-899X.

The structure of the electronic energy bands and Brillouin zones for graphite is developed using the tight-binding approximation.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaH2sXitlGlug%253D%253D&md5=c251838b74651969457f8e68a86bf822
7
Boehm, H. P.; Clauss, A.; Fisher, G. O.; Hofmann, U. Das Adsorptionsverhalten Sehr Dunner Kohlenstoff-Folien Z. Anorg. Allg. Chem. 1962, 316, 119– 127 DOI: 10.1002/zaac.19623160303

Google Scholar

7
The adsorption behavior of very thin carbon films

Boehm, H. P.; Clauss, A.; Fischer, G. O.; Hofmann, U.

Zeitschrift fuer Anorganische und Allgemeine Chemie (1962), 316 (), 119-27CODEN: ZAACAB; ISSN:0044-2313.

Very thin C films were formed by reducing dil. alk. suspensions of graphite oxide or by quickly heating graphite oxide to 300°. The adsorption of PhOH and methylene blue from soln. and of N from the vapor state, and the catalytic efficiency of these firms for the synthesis of HBr were detd. The values of sp. surface of reduced prepns. were greater when detd. by adsorption from soln. than by adsorption from the vapor state or by catalytic efficiency. These differences were attributed to differences in agglomeration during isolation of the films. Films prepd. thermally were porous and less agglomerated, and gave similar surface areas by all the methods of detn. The HBr synthesis is catalyzed chiefly on the basal surfaces of the graphite lattice.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaF38XksF2kuro%253D&md5=ee9c8052a142a00f7e28e0d5f77c95c7
8
Boehm, H. P.; Clauss, A.; Hofmann, U.; Fisher, G. O. Dunnste Kohlenstoff-Folien Z. Naturforsch., B: J. Chem. Sci. 1962, 17, 150 DOI: 10.1515/znb-1962-0302

Google Scholar

There is no corresponding record for this reference.
9
Hofmann, U.; Frenzel, A. Die Reduktion von Graphitoxyd mit Schwefelwasserstoff Colloid Polym. Sci. 1934, 68, 149– 151 DOI: 10.1007/BF01451376

Google Scholar

There is no corresponding record for this reference.
10
Van Bommel, A. J.; Crombeen, J. E.; Vantooren, A. LEED and Auger-Electron Observation of SiC (0001) Surface Surf. Sci. 1975, 48, 463– 472 DOI: 10.1016/0039-6028(75)90419-7

Google Scholar

There is no corresponding record for this reference.
11
Foster, L. M.; Long, G.; Stumpf, H. C. Production of Graphite Single Crystals by the Thermal Decomposition of Aluminium Carbide Am. Mineral. 1958, 43, 285– 296
Google Scholar

There is no corresponding record for this reference.
12
Land, T. A.; Michely, T.; Behm, R. J.; Hemminger, J. C.; Comsa, G. STM Investigation of Single Layer Graphite Structures Produced on Pt(111) by Hydrocarbon Decomposition Surf. Sci. 1992, 264, 261– 270 DOI: 10.1016/0039-6028(92)90183-7

Google Scholar

12
STM investigation of single layer graphite structures produced on platinum(111) by hydrocarbon decomposition

Land, T. A.; Michely, T.; Behm, R. J.; Hemminger, J. C.; Comsa, G.

Surface Science (1992), 264 (3), 261-70CODEN: SUSCAS; ISSN:0039-6028.

Scanning tunneling microscopy(STM) provides new insight into the nucleation, growth and nature of the graphite layer formed on Pt(111) by hydrocarbon decompn. Annealing an ethylene-covered surface to 800 K results in the formation of small (∼ 20-30 Å in diam.) graphite islands which initially are distributed uniformly over the surface. With further annealing >1000 K, the graphite is obsd. to accumulate, forming a layer at the lower step edges and also forming large, regularly shaped islands on the terraces. It was detd. that hydrocarbon decompn. at elevated temps. results in formation of a single layer of graphite on the Pt surface. It is interesting to note that in the STM images of this single layer of graphite only 3 of the 6 carbon atoms in the graphite lattice are visible. This result cannot be accounted for by the usual explanation given in terms of inequivalent carbons atoms for the bulk graphite surface. Superstructures with periodicities varying up to 22 Å are evident on the graphite areas and are due to a higher order commensurability of the graphite and Pt lattices at different relative rotations.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38XitVWksrs%253D&md5=cf480123184325cb5120209ce648fdab
13
Forbeaux, I.; Themlin, J. M.; Debever, J. M. Heteroepitaxial Graphite on 6H-SiC(0001): Interface Formation Through Conduction-Band Electronic Structure Phys. Rev. B: Condens. Matter Mater. Phys. 1998, 58, 16396– 16406 DOI: 10.1103/PhysRevB.58.16396

Google Scholar

There is no corresponding record for this reference.
14
Grima, J. N.; Winczewski, S.; Mizzi, L.; Grech, M. C.; Cauchi, R.; Gatt, R.; Attard, D.; Wojciechowski, K. W.; Rybicki, J. Tailoring Graphene to Achieve Negative Poisson’s Ratio Properties Adv. Mater. 2015, 27, 1455– 1459 DOI: 10.1002/adma.201404106

Google Scholar

14
Tailoring Graphene to Achieve Negative Poisson's Ratio Properties

Grima, Joseph N.; Winczewski, Szymon; Mizzi, Luke; Grech, Michael C.; Cauchi, Reuben; Gatt, Ruben; Attard, Daphne; Wojciechowski, Krzysztof W.; Rybicki, Jaroslaw

Advanced Materials (Weinheim, Germany) (2015), 27 (8), 1455-1459CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

Mol. dynamics simulations are used to show how the conformation of graphene can be modified through the introduction of defects so as to make it amenable to exhibit a neg. Poisson's ratio (auxeticity). We find that graphene can be turned to an auxetic form simply through the introduction of double vacancy defects of the 5-8-5 type. Results suggest a clear route for turning regular conventional graphene to an auxetic form through the introduction of defects so as to produce one of the thinnest auxetic materials known so far which may be made to achieve tailored anomalous neg. Poisson's ratio properties unattainable in pristine graphene under ambient conditions. The work presented here shows, for the first time, how graphene can be modified to mimic the behavior of a highly and densely wrinkled paper model to the extent that it can exhibit auxetic behavior under ambient conditions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVygsbrM&md5=154924fbf14d7de7e36527e37fd5a77b
15
Kroto, H. W.; Heath, J. R.; O’Brien, S. C.; Curl, R. F.; Smalley, R. E. C₆₀ – Buckminsterfullerene Nature 1985, 318, 162– 163 DOI: 10.1038/318162a0

Google Scholar

15
C60: buckminsterfullerene

Kroto, H. W.; Heath, J. R.; O'Brien, S. C.; Curl, R. F.; Smalley, R. E.

Nature (London, United Kingdom) (1985), 318 (6042), 162-3CODEN: NATUAS; ISSN:0028-0836.

Laser-induced vaporization of graphite produced a remarkably stable cluster, consisting of 60 C atoms. A truncated icosahedron is suggested, a polygon with 60 vertexes and 32 faces, 12 of which are pentagonal and 20 hexagonal. The C60 mol., which results when a C atom is placed at each vertex of this structure has all the valences satisfied by 2 single bonds and 1 double bond, has many resonance structures and appears to be arom.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL28XotVOktQ%253D%253D&md5=0ca5453a66ee1366682f56b357b40a10
16
Iijima, S.; Yudasaka, M.; Yamada, R.; Bandow, S.; Suenaga, K.; Kokai, F.; Takahashi, K. Nano-Aggregates of Single-Walled Graphitic Carbon Nano-Horns Chem. Phys. Lett. 1999, 309, 165– 170 DOI: 10.1016/S0009-2614(99)00642-9

Google Scholar

16
Nano-aggregates of single-walled graphitic carbon nano-horns

Iijima, S.; Yudasaka, M.; Yamada, R.; Bandow, S.; Suenaga, K.; Kokai, F.; Takahashi, K.

Chemical Physics Letters (1999), 309 (3,4), 165-170CODEN: CHPLBC; ISSN:0009-2614. (Elsevier Science B.V.)

We have found a new type of carbon particle produced by the CO2 laser ablation of carbon at room temp. without a metal catalyst. The product has a powder form of graphitic particles with a uniform size of about 80 nm. An individual particle is composed of an aggregate of many horn-shaped sheaths of single-walled graphene sheets, which we named carbon nano-horns. The nano-horns can be produced at about 10 g/h.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1MXlt1Wlu7Y%253D&md5=06ca65b6dcc43a47164144b8cb6677ba
17
Iijima, S. Helical Microtubules of Graphitic Carbon Nature 1991, 354, 56– 58 DOI: 10.1038/354056a0

Google Scholar

17
Helical microtubules of graphitic carbon

Iijima, Sumio

Nature (London, United Kingdom) (1991), 354 (6348), 56-8CODEN: NATUAS; ISSN:0028-0836.

The prepn. of a novel type of finite C structure consisting of needle-like tubes is reported. Produced using an arc-discharge evapn. method similar to that used for fullerenes synthesis, the needles grow at the neg. end of the electrode used for the arc discharge. Electron microscopy reveals that each needle comprises coaxial tubes of graphitic sheets, ranging from 2 to ∼50. On each tube, the C-atom hexagons are arranged in a helical fashion about the needle axis. The helical pitch varies from needle to needle and from tube to tube within a single needle. This helical structure may aid growth. The formation of these needles, ranging from a few to a few tens of nanometers in diam., suggests that engineering of C structures should be possible on scales considerably greater than those relevant to the fullerenes.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38Xmt1Ojtg%253D%253D&md5=ab9fd03bc14a16606749af946bac86bf
18
Iijima, S.; Ichihashi, T. Single-Shell Carbon Nanotubes of 1-nm Diameter Nature 1993, 363, 603– 605 DOI: 10.1038/363603a0

Google Scholar

18
Single-shell carbon nanotubes of 1-nm diameter

Iijima, Sumio; Ichihashi, Toshinari

Nature (London, United Kingdom) (1993), 363 (6430), 603-5CODEN: NATUAS; ISSN:0028-0836.

The synthesis of abundant single-shell tubes with diams. of ∼1 1 nm is reported. Whereas multi-shell nanotubes are formed on the C cathode, single-shell tubes grow in the gas phase. Electron diffraction from a single tube allows confirmation of the helical arrangement of C hexagons deduced previously for multi-shell tubes.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK3sXltVOrs7o%253D&md5=e6ac48c5bdb705820cb7b6484c0f26c0
19
Bethune, D. S.; Kiang, C. H.; de Vries, M. S.; Gorman, G.; Savoy, R.; Vazquez, J.; Beyers, R. Cobalt-Catalyzed Growth of Carbon Nanotubes with Single-Atomic-Layerwalls Nature 1993, 363, 605– 607 DOI: 10.1038/363605a0

Google Scholar

There is no corresponding record for this reference.
20
Geim, A. K.; Novoselov, K. S. The Rise of Graphene Nat. Mater. 2007, 6, 183– 191 DOI: 10.1038/nmat1849

Google Scholar

20
The rise of graphene

Geim, A. K.; Novoselov, K. S.

Nature Materials (2007), 6 (3), 183-191CODEN: NMAACR; ISSN:1476-1122. (Nature Publishing Group)

A review. Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when com. products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top expts. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXit1Khtrg%253D&md5=c2c02ce70a1725e6c559c173156568c5
21
Bolotin, K. I.; Sikes, K. J.; Jiang, Z.; Klima, M.; Fudenberg, G.; Hone, J.; Kim, P.; Stormer, H. L. Ultrahigh Electron Mobility in Suspended Graphene Solid State Commun. 2008, 146, 351– 355 DOI: 10.1016/j.ssc.2008.02.024

Google Scholar

21
Ultrahigh electron mobility in suspended graphene

Bolotin, K. I.; Sikes, K. J.; Jiang, Z.; Klima, M.; Fudenberg, G.; Hone, J.; Kim, P.; Stormer, H. L.

Solid State Communications (2008), 146 (9-10), 351-355CODEN: SSCOA4; ISSN:0038-1098. (Elsevier Ltd.)

We have achieved mobilities in excess of 200,000 cm2 V -1 s-1 at electron densities of ∼2 × 1011 cm-2 by suspending single layer graphene. Suspension ∼150 nm above a Si/SiO2 gate electrode and elec. contacts to the graphene was achieved by a combination of electron beam lithog. and etching. The specimens were cleaned in situ by employing current-induced heating, directly resulting in a significant improvement of elec. transport. Concomitant with large mobility enhancement, the widths of the characteristic Dirac peaks are reduced by a factor of 10 compared to traditional, nonsuspended devices. This advance should allow for accessing the intrinsic transport properties of graphene.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXls12qu7s%253D&md5=eb2106037936ae4e92f258596283c0c0
22
Abergel, D. S. L.; Apalkov, V.; Berashevich, J.; Ziegler, K.; Chakraborty, T. Properties of Graphene: a Theoretical Perspective Adv. Phys. 2010, 59, 261– 482 DOI: 10.1080/00018732.2010.487978

Google Scholar

22
Properties of graphene: a theoretical perspective

Abergel, D. S. L.; Apalkov, V.; Berashevich, J.; Ziegler, K.; Chakraborty, Tapash

Advances in Physics (2010), 59 (4), 261-482CODEN: ADPHAH; ISSN:0001-8732. (Taylor & Francis Ltd.)

A review. The electronic properties of graphene, a two-dimensional crystal of carbon atoms, are exceptionally novel. For instance, the low-energy quasiparticles in graphene behave as massless chiral Dirac fermions which has led to the exptl. observation of many interesting effects similar to those predicted in the relativistic regime. Graphene also has immense potential to be a key ingredient of new devices, such as single mol. gas sensors, ballistic transistors and spintronic devices. Bilayer graphene, which consists of two stacked monolayers and where the quasiparticles are massive chiral fermions, has a quadratic low-energy band structure which generates very different scattering properties from those of the monolayer. It also presents the unique property that a tunable band gap can be opened and controlled easily by a top gate. These properties have made bilayer graphene a subject of intense interest. In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the phys. properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theor. models. Recent experminental observations of a metal-insulator transition in hydrogenated graphene is discussed in terms of a self-consistent theory and compared with related numerical simulations. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodn. properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect and optical properties. Confinement of electrons in graphene is non-trivial due to Klein tunnelling. We review various theor. and exptl. studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane-gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXps1CnsrY%253D&md5=7931fdb5e977f07902e61454cd89cb20
23
Zhang, Z. Z.; Chang, K. Tuning of Energy Levels and Optical Properties of Graphene Quantum Dots Phys. Rev. B: Condens. Matter Mater. Phys. 2008, 77, 235411 DOI: 10.1103/PhysRevB.77.235411

Google Scholar

23
Tuning of energy levels and optical properties of graphene quantum dots

Zhang, Z. Z.; Chang, Kai; Peeters, F. M.

Physical Review B: Condensed Matter and Materials Physics (2008), 77 (23), 235411/1-235411/5CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)

The authors study theor. the magnetic levels and optical properties of zigzag- and armchair-edged hexagonal graphene quantum dots (GQDs) using the tight-binding method. A bound edge state at zero energy appears for the zigzag GQDs in the absence of a magnetic field. The magnetic levels of GQDs exhibit a Hofstadter-butterfly spectrum and approach the Landau levels of 2-dimensional graphene as the magnetic field increases. The optical properties are tuned by the size, the type of the edge, and the external magnetic field.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXot1ylt78%253D&md5=45958acd26d31feae8079506b7bc3fc9
24
Nakada, K.; Fujita, M.; Dresselhaus, G.; Dresselhaus, M. S. Edge State in Graphene Ribbons: Nanometer Size Effect and Edge Shape Dependence Phys. Rev. B: Condens. Matter Mater. Phys. 1996, 54, 17954– 17961 DOI: 10.1103/PhysRevB.54.17954

Google Scholar

24
Edge state in graphene ribbons: nanometer size effect and edge shape dependence

Nakada, Kyoko; Fujita, Mitsutaka; Dresselhaus, Gene; Dresselhaus, Mildred S.

Physical Review B: Condensed Matter (1996), 54 (24), 17954-17961CODEN: PRBMDO; ISSN:0163-1829. (American Physical Society)

Finite graphite systems having a zigzag edge exhibit a special edge state. The corresponding energy bands are almost flat at the Fermi level and thereby give a sharp peak in the d. of states. The charge d. in the edge state is strongly localized on the zigzag edge sites. No such localized state appears in graphite systems having an armchair edge. By utilizing the graphene ribbon model, we discuss the effect of the system size and edge shape on the special edge state. By varying the width of the graphene ribbons, we find that the nanometer size effect is crucial for detg. the relative importance of the edge state. We also have extended the graphene ribbon to have edges of a general shape, which is defined as a mixt. of zigzag and armchair sites. Examg. the relative importance of the edge state for graphene ribbons with general edges, we find that a non-negligible edge state survives even in graphene ribbons with less developed zigzag edges. We demonstrate that such an edge shape with three or four zigzag sites per sequence is sufficient to show an edge state, when the system size is on a nanometer scale. The special characteristics of the edge state play a large role in detg. the d. of states near the Fermi level for graphite networks on a nanometer scale.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2sXktlentA%253D%253D&md5=d0b337e10c39d36816b22e63d499ea4e
25
Kim, W. Y.; Kim, K. S. Prediction of Very Large Values of Magnetoresistance in a Graphene Nanoribbon Device Nat. Nanotechnol. 2008, 3, 408– 412 DOI: 10.1038/nnano.2008.163

Google Scholar

25
Prediction of very large values of magnetoresistance in a graphene nanoribbon device

Kim, Woo Youn; Kim, Kwang S.

Nature Nanotechnology (2008), 3 (7), 408-412CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)

Graphene has emerged as a versatile material with outstanding electronic properties that could prove useful in many device applications. Recently, the demonstration of spin injection into graphene and the observation of long spin relaxation times and lengths suggested that graphene could play a role in spintronic' devices that manipulate electron spin rather than charge. In particular zigzag graphene nanoribbons have magnetic (or spin) states at their edges, and these states can be either antiparallel or parallel. Here the authors report the results of 1st-principles simulations that predict that spin-valve devices based on graphene nanoribbons will exhibit magnetoresistance values that are thousands of times higher than previously reported exptl. values. These remarkable values can be linked to the unique symmetry of the band structure in the nanoribbons. Also it is possible to manipulate the band structure of the nanoribbons to generate highly spin-polarized currents. From 1st-principles computer simulations, theorists have predicted that zigzag graphene nanoribbons should display magnetoresistance values that are thousands of times higher than previously reported exptl. values, and also should be able to generate highly spin-polarized currents.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXotFehsLk%253D&md5=fd497e2f843acf889694071215685a91
26
Nair, R. R.; Blake, P.; Grigorenko, A. N.; Novoselov, K. S.; Booth, T. J.; Stauber, T.; Peres, N. M. R.; Geim, A. K. Fine Structure Constant Defines Visual Transparency of Graphene Science 2008, 320, 1308 DOI: 10.1126/science.1156965

Google Scholar

26
Fine Structure Constant Defines Visual Transparency of Graphene

Nair, R. R.; Blake, P.; Grigorenko, A. N.; Novoselov, K. S.; Booth, T. J.; Stauber, T.; Peres, N. M. R.; Geim, A. K.

Science (Washington, DC, United States) (2008), 320 (5881), 1308CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

There is a small group of phenomena in condensed matter physics that is defined only by the fundamental consts. and does not depend on material parameters. Examples are the resistivity quantum, h/e2 (h is Planck's const. and e the electron charge), that appears in a variety of transport expts. and the magnetic flux quantum, h/e, playing an important role in the physics of supercond. By and large, sophisticated facilities and special measurement conditions are required to observe any of these phenomena. We show that the opacity of suspended graphene is defined solely by the fine structure const., α = e2/ℏc ≈ 1/137 (where c is the speed of light), the parameter that describes coupling between light and relativistic electrons and that is traditionally assocd. with quantum electrodynamics rather than materials science. Despite being only one atom thick, graphene is found to absorb a significant (πα = 2.3%) fraction of incident white light, a consequence of graphene's unique electronic structure.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXmslWgt7k%253D&md5=e99cdff43e2bef193cf9767c6619b4da
27
Staudenmaier, L. Verfahren zur Darstellung der Graphitsäure Ber. Dtsch. Chem. Ges. 1898, 31, 1481– 1487 DOI: 10.1002/cber.18980310237

Google Scholar

27
Method for the preparation of graphitic acid. [machine translation]

Staudenmaier, L.

Berichte der Deutschen Chemischen Gesellschaft (1898), 31 (), 1481-87CODEN: BDCGAS; ISSN:0365-9496.

[Machine Translation of Descriptors]. The preparation of larger quantities of graphitic acid, C11H4O5 or C11H4O6, was a very lengthy after the known become method by treatment of Ceylon graphite with KClO3 + fuming nitric acid and because of the here frequently occurring explosions of chloric acid incompletely harmless operation; also relatively fastest the method of Moissan (C. r. d. l'Acad. des sciences 119. 976; 121. 538; C. 95. I. 355. II. 1014), leading to the goal, which on the application of anhydrous nitric acid and blown up graphite (C. r. d. l'Acad. des sciences 116. 608; C. 93. I. 852) been based, is not free from these grievances. Author and others represented that the subsequent method, which permits the application of larger quantities graphite, without an explosion of the ClO2 would be to be feared. In a mixture of 1 liter more roughly concentrated sulfuric acid nitric acid of the density 1.4, concentrated cooled down on room temperature, in a flat porcelain dish, with 1/2 l one stirs 25 g blown up graphite and then gradually 450 g KClO3; after repeated churning if the gas evolution left, and colors purely yellow a sample product with KMnO4, then one pours the whole in much water, is served and washed by decanting with water; one heats the green residue brought into a porcelain dish back then on the water bath with a solution of 7 g KMnO4 in 120 ccm with diluted sulfuric acid transferred water up to the disappearance of the red coloration; one gives on that a little H2O2 or hydrochloric acid in addition and leaves untouched still some time; finally those of graphite becomes according to Gottschalk (J. pr. Chem. 95. 321) with nitric acid of the density 1.28, then with alcohol and ether washed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaD28XisFCgtrk%253D&md5=90e7a3cb344a83afe48368a75e8631bb
28
Hummers, W. S.; Offeman, R. E. Preparation of Graphitic Oxide J. Am. Chem. Soc. 1958, 80, 1339 DOI: 10.1021/ja01539a017

Google Scholar

28
Preparation of graphitic oxide

Hummers, Wm. S., Jr.; Offeman, Richard E.

Journal of the American Chemical Society (1958), 80 (), 1339CODEN: JACSAT; ISSN:0002-7863.

See U.S. 2,798,878 (C.A. 51, 15080a).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaG1cXlt1yjuw%253D%253D&md5=04e888842c5cd001e1ac8daba8de2455
29
Marcano, D. C.; Kosynkin, D. V.; Berlin, J. M.; Sinitskii, A.; Sun, Z. Z.; Slesarev, A.; Alemany, L. B.; Lu, W.; Tour, J. M. Improved Synthesis of Graphene Oxide ACS Nano 2010, 4, 4806– 4814 DOI: 10.1021/nn1006368

Google Scholar

29
Improved Synthesis of Graphene Oxide

Marcano, Daniela C.; Kosynkin, Dmitry V.; Berlin, Jacob M.; Sinitskii, Alexander; Sun, Zhengzong; Slesarev, Alexander; Alemany, Lawrence B.; Lu, Wei; Tour, James M.

ACS Nano (2010), 4 (8), 4806-4814CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

An improved method for the prepn. of graphene oxide (GO) is described. Currently, Hummers' method (KMnO4, NaNO3, H2SO4) is the most common method used for prepg. graphene oxide. We have found that excluding the NaNO3, increasing the amt. of KMnO4, and performing the reaction in a 9:1 mixt. of H2SO4/H3PO4 improves the efficiency of the oxidn. process. This improved method provides a greater amt. of hydrophilic oxidized graphene material as compared to Hummers' method or Hummers' method with addnl. KMnO4. Moreover, even though the GO produced by our method is more oxidized than that prepd. by Hummers' method, when both are reduced in the same chamber with hydrazine, chem. converted graphene (CCG) produced from this new method is equiv. in its elec. cond. In contrast to Hummers' method, the new method does not generate toxic gas and the temp. is easily controlled. This improved synthesis of GO may be important for large-scale prodn. of GO as well as the construction of devices composed of the subsequent CCG.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXptFOqtrc%253D&md5=2d5c24d0c1af30a5cefdbcfa733e6240
30
Dryer, D. R.; Park, S.; Bielawski, C. W.; Ruoff, R. S. The Chemistry of Graphene Oxide Chem. Soc. Rev. 2010, 39, 229– 240 DOI: 10.1039/B917103G

Google Scholar

There is no corresponding record for this reference.
31
Hofmann, U.; Konig, E. Untersuchungen über Graphitoxyd Z. Anorg. Allg. Chem. 1937, 234, 311– 336 DOI: 10.1002/zaac.19372340405

Google Scholar

31
Investigations of graphitic oxide

Hofmann, Ulrich; Konig, Ernest

Zeitschrift fuer Anorganische und Allgemeine Chemie (1937), 234 (), 311-36CODEN: ZAACAB; ISSN:0044-2313.

From the agreement in sp. gr. as detd. under xylene and as calcd. from x-ray data, it follows that all the constituents present in appreciable quantity, except ash, are included in the elementary cell. On the edges of the lattice layers are carboxyl groups in which the H is replaceable with other cations, but the old designation of "graphitic acid" is nevertheless considered unsuitable, because active carbons of graphitic structure also possess such genuine acid properties. The name graphitic oxide is justified on the basis that in dry prepns., at least, an overwhelming proportion of the O is linked to the graphite planes. The electrochem. potential of graphitic oxide depends upon the surface oxides found in the external layers. The product obtained by reduction with N2H4.H2O contains up to 50% H2O after drying at 120°. This is because in the reduction a felt of very thin lamellae is produced, in which large quantities of H2O are held. This can be removed gradually by themal decompn. and by pressure. In either case, the thickness of the crystal lamellae grows in the direction of the c-axis. The structural unit of graphitic oxide is believed to be >C.sbd.C< O, which in H2O can be hydrolyzed to >C.sbd.C< OH OH.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaA1cXhsVSitQ%253D%253D&md5=ddf2ae4af1e795567e5d57c0296ac642
32
Fisher, E. Einfluss der Configuration auf die Wirkung der Enzyme Ber. Dtsch. Chem. Ges. 1894, 27, 2985– 2993 DOI: 10.1002/cber.18940270364

Google Scholar

There is no corresponding record for this reference.
33
Lehn, J. M. Supramolecular Chemistry: Concepts and Perspectives; Wiley: New York, 1995.

Google Scholar

There is no corresponding record for this reference.
34
McMurry, J.; Fayl McCarty, R. C. Chemistry; Pearson Education: New York, 2004.
Google Scholar

There is no corresponding record for this reference.
35
Lide, D. R. CRC Handbook of Chemistry and Physics, 85th ed.; Taylor & Francis: New York, 2004.
Google Scholar

There is no corresponding record for this reference.
36
Atkins, P.; de Paula, J. Physical Chemistry, 7th ed.; W. H. Freeman: New York, 2002.
Google Scholar

There is no corresponding record for this reference.
37
Steed, J. W.; Atwood, J. L. Supramolecular Chemistry, 2nd ed; Wiley: New York, 2013.
Google Scholar

There is no corresponding record for this reference.
38
Skinner, H. A.; Connor, J. A. Metal-Ligand Bond-Energies in Organometallic Compounds Pure Appl. Chem. 1985, 57, 79– 88 DOI: 10.1351/pac198557010079

Google Scholar

There is no corresponding record for this reference.
39
Smithrud, D. B.; Sanford, E. M.; Chao, I.; Ferguson, S. B.; Carcanague, D. R.; Evanseck, J. D.; Houk, K. N.; Diederich, F. Solvent Effects in Molecular Recognition Pure Appl. Chem. 1990, 62, 2227– 2236 DOI: 10.1351/pac199062122227

Google Scholar

39
Solvent effects in molecular recognition

Smithrud, D. B.; Sanford, E. M.; Chao, I.; Ferguson, S. B.; Carcanague, D. R.; Evanseck, J. D.; Houk, K. N.; Diederich, F.

Pure and Applied Chemistry (1990), 62 (12), 2227-36CODEN: PACHAS; ISSN:0033-4545.

Synthetic cyclophane hosts form stable and highly structured inclusion complexes with org. mols. in aq. solns. The soln. geometries of these complexes are detd. in a conformational anal. using Monte Carlo methods. Solvation-desolvation processes are a central factor in detg. the stability of apolar inclusion complexes. The tight binding of small arom. solutes in water in entropically unfavorable and is predominantly enthalpy-driven. A large part of the favorable enthalpy term for strong complexation in water results from its specific contributions. Electron donor-acceptor interactions stabilize complexes between electron-rich cyclophane hosts and electron-deficient arom. substrates; however, they may be masked by specific solvation effects. Computer liq. phase simulations are undertaken to evaluate at a microscopic level the origin of such solvation effects. The progress in the modeling studies is described. Apolar complexation also occurs in org. solvents. Solvents like 2,2,2-trifluoroethanol and ethylene glycol come close to water in their ability to promote apolar complexation. Binding strength decreases from water to polar protic to dipolar aprotic and to apolar solvents. Complexation strength in solvents of all polarity including water and in binary aq. solvent mixts. is predictable according to a linear free energy relationship between the complexation free energy and the empirical solvent polarity parameter ET(30).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK3MXhslamsro%253D&md5=a2f97351891f953b6c0ef14bc9bce378
40
Southall, N. T.; Dill, K. A.; Haymet, A. D. J. A View of the Hydrophobic Effect J. Phys. Chem. B 2002, 106, 521– 533 DOI: 10.1021/jp015514e

Google Scholar

40
A View of the Hydrophobic Effect

Southall, Noel T.; Dill, Ken A.; Haymet, A. D. J.

Journal of Physical Chemistry B (2002), 106 (3), 521-533CODEN: JPCBFK; ISSN:1089-5647. (American Chemical Society)

A review. Oil and water do not mix. The disaffinity of oil for water, with its unusual temp. dependence, is called the hydrophobic effect. It is important to understand the factors underlying the hydrophobic effect because they appear to play key roles in membrane and micelle formation, protein folding, ligand-protein and protein-protein binding, chromatog. retention, possibly nucleic acid interactions, and the partitioning of drugs, metabolites, and toxins throughout the environment and living systems. Here, we survey exptl. and theor. studies of nonpolar solute partitioning into water. We note that the hydrophobic effect is not just due to "water ordering" and not merely due to small size effects of water. The properties vary substantially with temp. and solute shape. Also, we discuss the limitations of using oil/water partitioning as the basis for some thermodn. models in chem. and biol.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXptFyjurY%253D&md5=f62d28e17b04a77912342f879de77a4b
41
Hunter, C. A.; Lawson, K. R.; Perkins, C.; Urch, C. J. Aromatic Interactions J. Chem. Soc. Perk. T. 2001, 2, 651– 669 DOI: 10.1039/b008495f

Google Scholar

There is no corresponding record for this reference.
42
Zhang, Z. X.; Huang, H. L.; Yang, X. M.; Zang, L. Tailoring Electronic Properties of Graphene by pi-pi Stacking with Aromatic Molecules J. Phys. Chem. Lett. 2011, 2, 2897– 2905 DOI: 10.1021/jz201273r

Google Scholar

42
Tailoring Electronic Properties of Graphene by π-π Stacking with Aromatic Molecules

Zhang, Zengxing; Huang, Helin; Yang, Xiaomei; Zang, Ling

Journal of Physical Chemistry Letters (2011), 2 (22), 2897-2905CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)

Intrinsic graphene is a semimetal or zero bandgap semiconductor, which hinders its applications for nanoelectronics. To develop high-performance nanodevices with graphene, it is necessary to open the bandgap and precisely control the charge carrier type and d. In this perspective, the authors focus on tailoring the electronic properties of graphene by noncovalent stacking with arom. mols. through π-π interaction. Different types of mols. (functioning as either an electron donor or acceptor when stacked with graphene) as reported in recent literature are presented regarding surface patterning, bandgap engineering, surface doping, as well as applications in nanodevices, particularly the field-effect transistors (FETs). From the current progress along this research line, future issues and challenges are also briefly discussed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtlOks7jP&md5=3c0dc6bb1ab40b465ff8813b41240283
43
Kozlov, S. M.; Vines, F.; Gorling, A. On the Interaction of Polycyclic Aromatic Compounds with Graphene Carbon 2012, 50, 2482– 2492 DOI: 10.1016/j.carbon.2012.01.070

Google Scholar

43
On the interaction of polycyclic aromatic compounds with graphene

Kozlov, Sergey M.; Vines, Francesc; Goerling, Andreas

Carbon (2012), 50 (7), 2482-2492CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

The adsorption and diffusion of benzene, hexafluorinated benzene, perylene, perylene-3,4,9,10-tetracarboxylic-3,4,9,10-diimide (PTCDI) and perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) on graphene was studied by d. functional means on a generalized gradient approxn. level, including a semi-empirical correction to account for dispersive forces. For all considered mols. the adsorption strength is mainly due to the latter, with the electronic interaction being relatively small and repulsive. As a rule-of-thumb, the strength of the adsorption interaction is 11-13 kJ mol-1 per C atom. The adsorption energies are large enough to avoid desorption at room temp. The estd. diffusion and rotation barriers are remarkably small, thus allowing a rapid diffusion and self-arrangement even at cryogenic temps. Finally, the adsorption of benzene or perylene derivs. may act, depending on the mol. and nature of the substituents, as a source for n- or p-doping, achieving up to 0.2 electrons(holes)/mol. The lowest unoccupied MOs of PTCDI and PTCDA are close in energy to the Dirac point of graphene and induce a conduction gap of ≈210-240 meV in the graphene band structure. Thus, they can be used for graphene band gap engineering and doping by the non-aggressive method of mol. adsorption.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XisFyjtbo%253D&md5=f7fc4d2c05285d4a6f75d76766065504
44
De Feyter, S.; De Schryver, F. C. Two-Dimensional Supramolecular Self-Assembly Probed by Scanning Tunneling Microscopy Chem. Soc. Rev. 2003, 32, 139– 150 DOI: 10.1039/b206566p

Google Scholar

44
Two-dimensional supramolecular self-assembly probed by scanning tunneling microscopy

De Feyter, Steven; De Schryver, Frans C.

Chemical Society Reviews (2003), 32 (3), 139-150CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)

A review. Supramol. chem. has a very large impact on chem. of current interest and the use of non-covalent but directional forces is appealing for the construction of supramol. architectures. The invention of scanning probe microscopy techniques has opened new doorways to study these concepts on surfaces. This review deals with recent progress in the study of two-dimensional supramol. self-assembly on surfaces probed by STM, with a special emphasis on structure, dynamics, and reactivity of hydrogen bonded systems.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXjtFGmt7g%253D&md5=4365d6f57f758462ad5685e951e007ff
45
Foster, J. S.; Frommer, J. E. Imaging of Liquid-Crystals Using a Tunnelling Microscope Nature 1988, 333, 542– 545 DOI: 10.1038/333542a0

Google Scholar

There is no corresponding record for this reference.
46
Griessl, S.; Lackinger, M.; Edelwirth, M.; Hietschold, M.; Heckl, W. M. Self-Assembled Two-Dimensional Molecular Host-Guest Architectures from Trimesic Acid Single Mol. 2002, 3, 25– 31 DOI: 10.1002/1438-5171(200204)3:1<25::AID-SIMO25>3.0.CO;2-K

Google Scholar

46
Self-assembled two-dimensional molecular host-guest architectures from trimesic acid

Griessl, Stefan; Lackinger, Markus; Edelwirth, Michael; Hietschold, Michael; Heckl, Wolfgang M.

Single Molecules (2002), 3 (1), 25-31CODEN: SGMCF7; ISSN:1438-5163. (Wiley-VCH Verlag Berlin GmbH)

The adsorption of 1,3,5-benzenetricarboxylic (Trimesic) Acid (TMA) to a single crystal graphite surface has been studied under Ultra High Vacuum conditions. This work focuses on inducing a particular self-assembly structure by OMBE (Org. Mol. Beam Epitaxy), characterized by periodic non-dense-packing of the mols. Two coexisting phases could be imaged with sub-mol. resoln. by STM. Induced by directed hydrogen bonding, the org. mols. built in both cases a two-dimensional grid architecture with mol. caves. This two-dimensional host structure can accept single trimesic acid guest mols. in different positions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XjtlWls7Y%253D&md5=14cb94ea07262b7032528748e96c69b9
47
Lackinger, M.; Griessl, S.; Heckl, W. M.; Hietschold, M. STM and STS of Coronene on HOPG(0001) in UHV – Adsorption of the Smallest Possible Graphite Flakes on Graphite Anal. Bioanal. Chem. 2002, 374, 685– 687 DOI: 10.1007/s00216-002-1458-9

Google Scholar

47
STM and STS of coronene on HOPG(0001) in UHV. Adsorption of the smallest possible graphite flakes on graphite

Lackinger, Markus; Griessl, Stefan; Heckl, Wolfgang M.; Hietschold, Michael

Analytical and Bioanalytical Chemistry (2002), 374 (4), 685-687CODEN: ABCNBP; ISSN:1618-2642. (Springer-Verlag)

The adsorption of the arom. mol. hexabenzobenzene (coronene) on an HOPG(0001) surface was investigated under UHV conditions by means of variable temp. scanning tunneling microscopy (STM) and spectroscopy (STS). Imaging on a mesoscopic scale showed a distribution of coronene islands. These islands are mobile on the surface and can be pinned at step-edges. Zooming in on areas apart from the islands reveals an hexagonal arrangement of coronene mols. in a closed layer. Submol. resolved mols. consist of bright spots with varying intensity. This variation in intensity is explained with the commensurability of the adlayer. STS investigations were performed for various tip-sample distances, adjusted by the tunneling current setpoint. A gap can be seen for every setpoint, but its width is dependent on the setpoint. The gap for the largest tip-sample distance and therefore the smallest tip-sample interaction is compared with the theor. value.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XotV2jt7Y%253D&md5=a8837eb01d5927f3b205265ebb2d2be4
48
Shayeganfar, F.; Rochefort, A. Electronic Properties of Self-Assembled Trimesic Acid Monolayer on Graphene Langmuir 2014, 30, 9707– 9716 DOI: 10.1021/la501619b

Google Scholar

48
Electronic Properties of Self-Assembled Trimesic Acid Monolayer on Graphene

Shayeganfar, F.; Rochefort, A.

Langmuir (2014), 30 (32), 9707-9716CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)

The adsorption of trimesic acid (TMA) on a graphene surface was studied with d. functional theory. By considering the adsorption of a single TMA mol. on different sites on graphene, the authors were able to perform a detailed anal. of the equil. geometry, charge transfer, electronic properties in terms of d. of states and band structure, and finally scanning tunneling microscopy simulations on those simple systems. The results for isolated adsorption were then compared to the behavior of the TMA unit within two different self-assembled monolayers. The authors' results indicate that structural deformations of TMA may significantly contribute to the magnitude of p-doping and band gap opening in graphene. The formation of a hydrogen bonding network within the assembly improves the stability of the adlayer, but its adhesion on graphene is significantly reduced. The magnitude of p-doping in graphene per TMA unit remains nearly const. from the isolated to the assembled systems, but the magnitude of the band gap opening appears to be strongly correlated with the breaking of symmetry of π-states of graphene by the TMA patterning on the surface. The results suggest that polymorphism in self-assembled adlayers could be used to tune and control the electronic properties of graphene.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1eks7jL&md5=5bdafc9ba61c87886a7a018d684fe143
49
Zhou, Q.; Li, Y.; Li, Q.; Wang, Y.; Yang, Y.; Fang, Y.; Wang, C. Switchable Supramolecular Assemblies on Graphene Nanoscale 2014, 6, 8387– 8391 DOI: 10.1039/c4nr01796j

Google Scholar

49
Switchable supramolecular assemblies on graphene

Zhou, Qiaoyu; Li, Yibao; Li, Qiang; Wang, Yibing; Yang, Yanlian; Fang, Ying; Wang, Chen

Nanoscale (2014), 6 (14), 8387-8391CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

Self-assembly of trimesic acid on single- and few-layer graphene supported by SiO2 substrates has been studied. A scanning tunneling microscope operated under ambient conditions was utilized to image supramol. networks of trimesic acid at liq.-graphene interfaces. Trimesic acid self-assembled into large-scale, highly ordered adlayers on graphene surfaces. Phase transition of the trimesic acid adlayer from a close-packed structure to a porous chicken-wire structure was obsd. by changing from single- to few-layer graphene, which was attributed to the modulation of mol.-graphene interactions by the layer no. of graphene. The guest-induced phase transition of trimesic acid by complexation with coronene on single-layer graphene further confirms that supramol. networks on graphene can be rationally tailored with sub-nanometer resoln. by balancing between intermol. vs. mol.-graphene interactions. The effects of trimesic acid adlayers on the electronic transport properties of graphene transistors were investigated. The adsorption of trimesic acid induced p-doping and defects in the adlayers cause scattering of charge carriers in single-layer graphene.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVKjtrrL&md5=3371cfdf0085e975227bf4617988bc7a
50
MacLeod, J. M.; Lipton-Duffin, J. A.; Cui, D.; De Feyter, S.; Rosei, F. Substrate Effects in the Supramolecular Assembly of 1,3,5-Benzene Tricarboxylic Acid on Graphite and Graphene Langmuir 2015, 31, 7016– 7024 DOI: 10.1021/la5048886

Google Scholar

50
Substrate Effects in the Supramolecular Assembly of 1,3,5-Benzene Tricarboxylic Acid on Graphite and Graphene

MacLeod, J. M.; Lipton-Duffin, J. A.; Cui, D.; De Feyter, S.; Rosei, F.

Langmuir (2015), 31 (25), 7016-7024CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)

The behavior of small mols. on a surface depends critically on both mol.-substrate and intermol. interactions. We present here a detailed comparative investigation of 1,3,5-benzene tricarboxylic acid (trimesic acid, TMA) on two different surfaces: highly oriented pyrolytic graphite (HOPG) and single-layer graphene (SLG) grown on a polycryst. Cu foil. On the basis of high-resoln. scanning tunnelling microscopy (STM) images, we show that the epitaxy matrix for the hexagonal TMA chicken wire phase is identical on these two surfaces, and, using d. functional theory (DFT) with a non-local van der Waals correlation contribution, we identify the most energetically favorable adsorption geometries. Simulated STM images based on these calcns. suggest that the TMA lattice can stably adsorb on sites other than those identified to maximize binding interactions with the substrate. This is consistent with our net energy calcns. that suggest that intermol. interactions (TMA-TMA dimer bonding) are dominant over TMA-substrate interactions in stabilizing the system. STM images demonstrate the robustness of the TMA films on SLG, where the mol. network extends across the variable topog. of the SLG substrates and remains intact after rinsing and drying the films. These results help to elucidate mol. behavior on SLG and suggest significant similarities between adsorption on HOPG and SLG.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtVSiur0%253D&md5=f8a04bc8b3824c17a8574a9a9fdffcff
51
Chen, W.; Chen, S.; Qi, D. C.; Gao, X. Y.; Wee, A. T. S. Surface Transfer p-Type Doping of Epitaxial Graphene J. Am. Chem. Soc. 2007, 129, 10418– 10422 DOI: 10.1021/ja071658g

Google Scholar

51
Surface Transfer p-Type Doping of Epitaxial Graphene

Chen, Wei; Chen, Shi; Qi, Dong Chen; Gao, Xing Yu; Wee, Andrew Thye Shen

Journal of the American Chemical Society (2007), 129 (34), 10418-10422CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

Epitaxial graphene thermally grown on 6H-SiC(0001) can be p-type doped via a novel surface transfer doping scheme by modifying the surface with the electron acceptor, tetrafluoro-tetracyanoquinodimethane (F4-TCNQ). Synchrotron-based high-resoln. photoemission spectroscopy reveals that electron transfer from graphene to adsorbed F4-TCNQ is responsible for the p-type doping of graphene. This novel surface transfer doping scheme by surface modification with appropriate mol. acceptors represents a simple and effective method to nondestructively dope epitaxial graphene for future nanoelectronics applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXotlCrur4%253D&md5=a03351dd2efa54aa4e230bde96dbaa4c
52
Coletti, C.; Riedl, C.; Lee, D. S.; Krauss, B.; Patthey, L.; von Klitzing, K.; Smet, J. H.; Starke, U. Charge Neutrality and Band-Gap Tuning of Epitaxial Graphene on SiC by Molecular Doping Phys. Rev. B: Condens. Matter Mater. Phys. 2010, 81, 235401 DOI: 10.1103/PhysRevB.81.235401

Google Scholar

52
Charge neutrality and band-gap tuning of epitaxial graphene on SiC by molecular doping

Coletti, C.; Riedl, C.; Lee, D. S.; Krauss, B.; Patthey, L.; von Klitzing, K.; Smet, J. H.; Starke, U.

Physical Review B: Condensed Matter and Materials Physics (2010), 81 (23), 235401/1-235401/8CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)

Epitaxial graphene on SiC(0001) suffers from strong intrinsic n-type doping. The excess neg. charge can be fully compensated by noncovalently functionalizing graphene with the strong electron-acceptor tetrafluorotetracyanoquinodimethane (F4-TCNQ). Charge neutrality can be reached in monolayer graphene as shown in electron-dispersion spectra from angular-resolved photoemission spectroscopy. In bilayer graphene the band-gap that originates from the SiC/graphene interface dipole increases with increasing F4-TCNQ deposition and, as a consequence of the mol. doping, the Fermi level is shifted into the band-gap. The redn. in the charge-carrier d. upon mol. deposition is quantified using electronic Fermi surfaces and Raman spectroscopy. The structural and electronic characteristics of the graphene/F4-TCNQ charge-transfer complex are investigated by XPS and UPS. The doping effect on graphene is preserved in air and is temp. resistant up to 200°. Furthermore, graphene noncovalent functionalization with F4-TCNQ can be implemented not only via evapn. in ultrahigh vacuum but also by wet chem.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXosVynurw%253D&md5=eb2600b204dfb5f478c14873223df6e5
53
Stradi, D.; Garnica, M.; Diaz, C.; Calleja, F.; Barja, S.; Martin, N.; Alcami, M.; de Parga, A. L. V.; Miranda, R.; Martin, F. Controlling the Spatial Arrangement of Organic Magnetic Anions Adsorbed on Epitaxial Graphene on Ru(0001) Nanoscale 2014, 6, 15271– 15279 DOI: 10.1039/C4NR02917H

Google Scholar

There is no corresponding record for this reference.
54
Huang, H.; Chen, S.; Gao, X.; Chen, W.; Wee, A. T. S. Structural and Electronic Properties of PTCDA Thin Films on Epitaxial Graphene ACS Nano 2009, 3, 3431– 3436 DOI: 10.1021/nn9008615

Google Scholar

54
Structural and electronic properties of PTCDA thin films on epitaxial graphene

Huang, Han; Chen, Shi; Gao, Xingyu; Chen, Wei; Wee, Andrew Thye Shen

ACS Nano (2009), 3 (11), 3431-3436CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

In situ low-temp. scanning tunneling microscopy is used to study the growth of 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) on epitaxial graphene (EG) on 6H-SiC(0001), as well as on HOPG for comparison. PTCDA adopts a layer-by-layer growth mode, with its mol. plane lying flat on both surfaces. The PTCDA films grow continuously over the EG step edges, but not on HOPG. STS performed on single-layer PTCDA on monolayer EG shows a wide band gap larger than 3.3 eV, consistent with pristine PTCDA films. Synchrotron-based high-resoln. photoemission spectroscopy reveals weak charge transfer between PTCDA and EG. This suggests weak electronic coupling between PTCDA and the underlying EG layer.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtlSls7vL&md5=aaecd3399bbb16d4698578d1a0ab6914
55
Lauffer, P.; Emtsev, K. V.; Graupner, R.; Seyller, T.; Ley, L. Molecular and Electronic Structure of PTCDA on Bilayer Graphene on SiC(0001) Studied with Scanning Tunneling Microscopy Phys. Status Solidi B 2008, 245, 2064– 2067 DOI: 10.1002/pssb.200879615

Google Scholar

55
Molecular and electronic structure of PTCDA on bilayer graphene on SiC(0001) studied with scanning tunneling microscopy

Lauffer, Peter; Emtsev, Konstantin V.; Graupner, Ralf; Seyller, Thomas; Ley, Lothar

Physica Status Solidi B: Basic Solid State Physics (2008), 245 (10), 2064-2067CODEN: PSSBBD; ISSN:0370-1972. (Wiley-VCH Verlag GmbH & Co. KGaA)

Epitaxial growth of graphene on SiC surfaces by solid state graphitization is a promising route for future development of graphene based electronics. We study the morphol. and mol. scale structure of monolayer films of 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) on bilayer graphene on SiC(0001) by scanning tunneling microscopy (STM). First we discuss how the PTCDA mols. adsorb on bilayer graphene. We specially regard the d. of PTCDA mols. at monolayer coverage. From the comparison with expts. on HOPG (Au(111) and Ag(110) from literature) we infer a non-planar adsorption geometry of PTCDA mols. on bilayer graphene. The electronic structure of the surrounding bilayer graphene substrate is investigated via scanning tunneling spectroscopy (STS) and reveals n-type doping of bilayer graphene during adsorption of PTCDA.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXht12itr3P&md5=a56ecbab414c366796777478530ca6df
56
Wang, Q. H.; Hersam, M. C. Room-Temperature Molecular-Resolution Characterization of Self-Assembled Organic Monolayers on Epitaxial Graphene Nat. Chem. 2009, 1, 206– 211 DOI: 10.1038/nchem.212

Google Scholar

56
Room-temperature molecular-resolution characterization of self-assembled organic monolayers on epitaxial graphene

Wang, Qing Hua; Hersam, Mark C.

Nature Chemistry (2009), 1 (3), 206-211, s206/1-s206/4CODEN: NCAHBB; ISSN:1755-4330. (Nature Publishing Group)

Graphene, a two-dimensional sheet of carbon atoms, is a promising material for next-generation technol. because of its advantageous electronic properties, such as extremely high carrier mobilities. However, chem. functionalization schemes are needed to integrate graphene with the diverse range of materials required for device applications. The authors report self-assembled monolayers of the mol. semiconductor perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) formed on epitaxial graphene grown on the SiC(0001) surface. The mols. possess long-range order with a herringbone arrangement, as shown by ultra-high vacuum scanning tunneling microscopy at room temp. The mol. ordering is unperturbed by defects in the epitaxial graphene or at. steps in the underlying SiC surface. Scanning tunnelling spectra of the PTCDA monolayer show distinct features that are not obsd. on pristine graphene. The demonstration of robust, uniform org. functionalization of epitaxial graphene presents opportunities for graphene-based mol. electronics and sensors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXmtF2rsL4%253D&md5=1a8685e99fdf539ed2f0a69da9f37a13
57
Emery, J. D.; Wang, Q. H.; Zarrouati, M.; Fenter, P.; Hersam, M. C.; Bedzyk, M. J. Structural Analysis of PTCDA Monolayers on Epitaxial Graphene with Ultra-High Vacuum Scanning Tunneling Microscopy and High-Resolution X-ray Reflectivity Surf. Sci. 2011, 605, 1685– 1693 DOI: 10.1016/j.susc.2010.11.008

Google Scholar

57
Structural analysis of PTCDA monolayers on epitaxial graphene with ultra-high vacuum scanning tunneling microscopy and high-resolution X-ray reflectivity

Emery, Jonathan D.; Wang, Qing Hua; Zarrouati, Marie; Fenter, Paul; Hersam, Mark C.; Bedzyk, Michael J.

Surface Science (2011), 605 (17-18), 1685-1693CODEN: SUSCAS; ISSN:0039-6028. (Elsevier B.V.)

Epitaxial graphene, grown by thermal decompn. of the SiC (0001) surface, is a promising material for future applications due to its unique and superlative electronic properties. However, the innate chem. passivity of graphene presents challenges for integration with other materials for device applications. Here, we present structural characterization of epitaxial graphene functionalized by the org. semiconductor perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). A combination of ultra-high vacuum scanning tunneling microscopy (STM) and high-resoln. X-ray reflectivity (XRR) is used to ext. lateral and vertical structures of 0, 1, and 2 monolayer (ML) PTCDA on epitaxial graphene. Both Fienup-based phase-retrieval algorithms and model-based least-squares analyses of the XRR data are used to ext. an electron d. profile that is interpreted in terms of a stacking sequence of mol. layers with specific interlayer spacings. Features in the STM and XRR anal. indicate long-range mol. ordering and weak π-π* interactions binding PTCDA mols. to the graphene surface. The high degree of both lateral and vertical ordering of the self-assembled film demonstrates PTCDA functionalization as a viable route for templating graphene for the growth and deposition of addnl. materials required for next-generation electronics and sensors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXpt1Cnsbw%253D&md5=1ef62de746ba8276b7ce53bba68b4645
58
Pollard, A. J.; Perkins, E. W.; Smith, N. A.; Saywell, A.; Goretzki, G.; Phillips, A. G.; Argent, S. P.; Sachdev, H.; Mueller, F.; Huefner, S. Supramolecular Assemblies Formed on an Epitaxial Graphene Superstructure Angew. Chem., Int. Ed. 2010, 49, 1794– 1799 DOI: 10.1002/anie.200905503

Google Scholar

58
Supramolecular Assemblies Formed on an Epitaxial Graphene Superstructure

Pollard, Andrew J.; Perkins, Edward W.; Smith, Nicholas A.; Saywell, Alex; Goretzki, Gudrun; Phillips, Anna G.; Argent, Stephen P.; Sachdev, Hermann; Mueller, Frank; Huefner, Stefan; Gsell, Stefan; Fischer, Martin; Schreck, Matthias; Osterwalder, Juerg; Greber, Thomas; Berner, Simon; Champness, Neil R.; Beton, Peter H.

Angewandte Chemie, International Edition (2010), 49 (10), 1794-1799, S1794/1-S1794/10CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

We studied the adsorption of perylene tetracarboxylic diimide and related derivs. on a graphene monolayer. It shows that a near-commensurability between their mol. dimensions and a moire-like superstructures leads to the stabilization of extended 1D assemblies.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXivFamsL4%253D&md5=ba79372f3d0d0ea0c700ad041b9e6d45
59
Karmel, H. J.; Garramone, J. J.; Emery, J. D.; Kewalramani, S.; Bedzyk, M. J.; Hersam, M. C. Self-Assembled Organic Monolayers on Epitaxial Graphene with Enhanced Structural and Thermal Stability Chem. Commun. 2014, 50, 8852– 8855 DOI: 10.1039/C4CC02761B

Google Scholar

There is no corresponding record for this reference.
60
Kozlov, S. M.; Vines, F.; Gorling, A. Bandgap Engineering of Graphene by Physisorbed Adsorbates Adv. Mater. 2011, 23, 2638– 2643 DOI: 10.1002/adma.201100171

Google Scholar

60
Bandgap Engineering of Graphene by Physisorbed Adsorbates

Kozlov, Sergey M.; Vines, Francesc; Goerling, Andreas

Advanced Materials (Weinheim, Germany) (2011), 23 (22-23), 2638-2643CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

We show that a tailor-made bandgap engineering of graphene is possible by physisorbing mols. with a specific electronic structure. By means of calcns. based on d.-functional theory (DFT), we show that suitable adsorbate mols. with the required specific electronic structure exist and that their adsorption has significant and sizeable effects on the graphene band structure. In this work, perylene-3,4,9,10-tetracarboxylic-3,4,9,10-diimide (PTCDI) is used to change the bandgap of graphene. The present findings clearly reveal that the conditions for bandgap opening are well defined, and the size and character of the bandgaps are tunable by varying the adsorbed mol., its coverage, its proximity to the graphene layer and by chem. changing the mol. electronic structure, e.g., by appropriate substituents.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXns1Crsb0%253D&md5=15db7b0e4235082a581f3d05c509906e
61
Zhang, L. M.; Yu, J. W.; Yang, M. M.; Xie, Q.; Peng, H. L.; Liu, Z. F. Janus Graphene from Asymmetric Two-Dimensional Chemistry Nat. Commun. 2013, 4, 1443 DOI: 10.1038/ncomms2464

Google Scholar

61
Janus graphene from asymmetric two-dimensional chemistry

Zhang Liming; Yu Jingwen; Yang Mingmei; Xie Qin; Peng Hailin; Liu Zhongfan

Nature communications (2013), 4 (), 1443 ISSN:.

Janus materials have distinct surfaces on their opposite faces. Graphene, a two-dimensional giant molecule, provides an excellent candidate to fabricate the thinnest Janus discs and study the asymmetric chemistry of atomic-thick nanomembranes using covalent chemical functionalisation. Here we present the first experimental realisation of nonsymmetrically modified single-layer graphene--Janus graphene--which is fabricated by a two-step surface covalent functionalisation assisted by a poly(methyl methacrylate)-mediated transfer approach. Four types of Janus graphene are produced by co-grafting of halogen and aryl/oxygen-functional groups on each side. Chemical decorations on one side are found to be capable of affecting both chemical reactivity and physical wettability of the opposite side, indicative of communication between the two grafted groups. This novel asymmetric structure provides a platform for theoretical and experimental studies of two-dimensional chemistry and graphene devices with multiple functions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3szlvFCjug%253D%253D&md5=6dcae184c47da7ce2084f83547b36ae5
62
Hernandez, Y.; Nicolosi, V.; Lotya, M.; Blighe, F. M.; Sun, Z.; De, S.; McGovern, I. T.; Holland, B.; Byrne, M.; Gun’Ko, Y. K. High-Yield Production of Graphene by Liquid-Phase Exfoliation of Graphite Nat. Nanotechnol. 2008, 3, 563– 568 DOI: 10.1038/nnano.2008.215

Google Scholar

62
High-yield production of graphene by liquid-phase exfoliation of graphite

Hernandez, Yenny; Nicolosi, Valeria; Lotya, Mustafa; Blighe, Fiona M.; Sun, Zhenyu; De, Sukanta; McGovern, I. T.; Holland, Brendan; Byrne, Michele; Gun'Ko, Yurii K.; Boland, John J.; Niraj, Peter; Duesberg, Georg; Krishnamurthy, Satheesh; Goodhue, Robbie; Hutchison, John; Scardaci, Vittorio; Ferrari, Andrea C.; Coleman, Jonathan N.

Nature Nanotechnology (2008), 3 (9), 563-568CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)

Fully exploiting the properties of graphene will require a method for the mass prodn. of this remarkable material. Two main routes are possible: large-scale growth or large-scale exfoliation. Here, we demonstrate graphene dispersions with concns. up to ∼0.01 mg mL-1, produced by dispersion and exfoliation of graphite in org. solvents such as N-methyl-pyrrolidone. This is possible because the energy required to exfoliate graphene is balanced by the solvent-graphene interaction for solvents whose surface energies match that of graphene. We confirm the presence of individual graphene sheets by Raman spectroscopy, transmission electron microscopy and electron diffraction. Our method results in a monolayer yield of ∼1 wt%, which could potentially be improved to 7-12 wt% with further processing. The absence of defects or oxides is confirmed by x-ray photoelectron, IR, and Raman spectroscopies. We are able to produce semi-transparent conducting films and conducting composites. Soln. processing of graphene opens up a range of potential large-area applications, from device and sensor fabrication to liq.-phase chem. Fully exploiting the properties of graphene will require a method for the mass prodn. of this remarkable material. The dispersion and exfoliation of graphite in org. solvents can produce graphene monolayers with a yield of about 1% by wt. Moreover, these samples are free from defects and oxides, and can be used to produce semi-transparent conducting films and conducting composites.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXhtVOqsLvM&md5=b7159800e921433bc1ff1aead8bbbdbe
63
Pykal, M.; Safarova, K.; Siskova, K. M.; Jurecka, P.; Bourlinos, A. B.; Zboril, R.; Otyepka, M. Lipid Enhanced Exfoliation for Production of Graphene Nanosheets J. Phys. Chem. C 2013, 117, 11800– 11803 DOI: 10.1021/jp401277g

Google Scholar

63
Lipid Enhanced Exfoliation for Production of Graphene Nanosheets

Pykal, Martin; Safarova, Klara; Machalova Siskova, Karolina; Jurecka, Petr; Bourlinos, Athanasios B.; Zboril, Radek; Otyepka, Michal

Journal of Physical Chemistry C (2013), 117 (22), 11800-11803CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)

Liq.-phase exfoliation of graphite is a widely used method to obtain graphene nanosheets, and therefore the development of a simple and efficient exfoliation procedure remains challenging. Here, we present a one-step method of graphene exfoliation in lecithin/chloroform soln. The graphene nanosheets produced by the lecithin-assisted exfoliation method were analyzed by microscopy techniques, including statistical anal. of at. force microscopy (AFM) images and Raman spectroscopy, which both indicate the presence of few-layer graphene nanosheets, including substantial content of three-layer sheets. Mol. dynamics simulations on the time scale of 0.5+ μs suggested that stability of the obtained colloid may originate from formation of lecithin reverse hemimicelles and micelles, which prevents the aggregation of exfoliated graphene flakes by entropic repulsion of the lipid hydrophobic chains.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXnsVKrtLc%253D&md5=78c18fd0dd011a928da456031d675933
64
Hernandez, Y.; Lotya, M.; Rickard, D.; Bergin, S. D.; Coleman, J. N. Measurement of Multicomponent Solubility Parameters for Graphene Facilitates Solvent Discovery Langmuir 2010, 26, 3208– 3213 DOI: 10.1021/la903188a

Google Scholar

64
Measurement of Multicomponent Solubility Parameters for Graphene Facilitates Solvent Discovery

Hernandez, Yenny; Lotya, Mustafa; Rickard, David; Bergin, Shane D.; Coleman, Jonathan N.

Langmuir (2010), 26 (5), 3208-3213CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)

We have measured the dispersibility of graphene in 40 solvents, with 28 of them previously unreported. We have shown that good solvents for graphene are characterized by a Hildebrand soly. parameter of δT ∼ 23 MPa1/2 and Hansen soly. parameters of δD ∼ 18 MPa1/2, δP ∼ 9.3 MPa1/2, and δH ∼ 7.7 MPa1/2. The dispersibility is smaller for solvents with Hansen parameters further from these values. We have used transmission electron microscopy (TEM) anal. to show that the graphene is well exfoliated in all cases. Even in relatively poor solvents, >63% of obsd. flakes have <5 layers.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtlCkur3F&md5=6f29d613b6521b3085d1f4d7bfbdaf8b
65
Khan, U.; O’Neill, A.; Lotya, M.; De, S.; Coleman, J. N. High-Concentration Solvent Exfoliation of Graphene Small 2010, 6, 864– 871 DOI: 10.1002/smll.200902066

Google Scholar

65
High-Concentration Solvent Exfoliation of Graphene

Khan, Umar; O'Neill, Arlene; Lotya, Mustafa; De, Sukanta; Coleman, Jonathan N.

Small (2010), 6 (7), 864-871CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)

A method is demonstrated to prep. graphene dispersions at high concns., up to 1.2 mg mL-1, with yields of up to 4 wt% monolayers. This process relies on low-power sonication for long times, up to 460 h. Transmission electron microscopy shows the sonication to reduce the flake size, with flake dimensions scaling as t-1/2. However, the mean flake length remains above 1 μm for all sonication times studied. Raman spectroscopy shows defects are introduced by the sonication process. However, detailed anal. suggests that predominately edge, rather than basal-plane, defects are introduced. These dispersions are used to prep. high-quality free-standing graphene films. The dispersions can be heavily dild. by water without sedimentation or aggregation. This method facilitates graphene processing for a range of applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXktFGmtLk%253D&md5=e4b650ba820678c7cb904f31a0d3f9d6
66
O’Neill, A.; Khan, U.; Nirmalraj, P. N.; Boland, J.; Coleman, J. N. Graphene Dispersion and Exfoliation in Low Boiling Point Solvents J. Phys. Chem. C 2011, 115, 5422– 5428 DOI: 10.1021/jp110942e

Google Scholar

66
Graphene Dispersion and Exfoliation in Low Boiling Point Solvents

O'Neill, Arlene; Khan, Umar; Nirmalraj, Peter N.; Boland, John; Coleman, Jonathan N.

Journal of Physical Chemistry C (2011), 115 (13), 5422-5428CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)

One of the problems with solvent exfoliation of graphene is that the best solvents tend to have high b.ps. and so are difficult to remove and can present problems for flake deposition and composite formation. Here, we demonstrate the exfoliation of graphene at relatively high concn. in low b.p. solvents such as chloroform and isopropanol. It is possible to achieve concns. of up to 0.5 mg/mL, just under half that which can be achieved with high b.p. solvents such as N-methyl-pyrrolidone. These dispersions consist of graphene flakes of ∼1 μm length and with a thickness of less than 10 layers (≤5 layers for isopropanol). For both solvents, >75% of the graphene remains dispersed indefinitely. Raman spectroscopy shows the flakes to be relatively defect-free. A significant advantage of low b.p. solvents is that they allow individual flakes to be spray cast onto substrates. Deposited densities of >10 flakes with length >1 μm per 10 μm × 10 μm square have been controllably achieved. While some on-substrate aggregation is obsd., this is much less prevalent than when spraying from high b.p. solvents.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXjtVKhtLk%253D&md5=f058605f3a536a5bebdff17d238f4fb3
67
Coleman, J. N. Liquid Exfoliation of Defect-Free Graphene Acc. Chem. Res. 2013, 46, 14– 22 DOI: 10.1021/ar300009f

Google Scholar

67
Liquid exfoliation of defect-free graphene

Coleman, Jonathan N.

Accounts of Chemical Research (2013), 46 (1), 14-22CODEN: ACHRE4; ISSN:0001-4842. (American Chemical Society)

A review. Due to its unprecedented phys. properties, graphene has generated huge interest over the last 7 years. Graphene is generally fabricated in one of two ways: as very high quality sheets produced in limited quantities by micromech. cleavage or vapor growth or as a rather defective, graphene-like material, graphene oxide, produced in large quantities. However, a growing no. of applications would profit from the availability of a method to produce high-quality graphene in large quantities. This Account describes recent work to develop such a processing route inspired by previous theor. and exptl. studies on the solvent dispersion of carbon nanotubes. That work had shown that nanotubes could be effectively dispersed in solvents whose surface energy matched that of the nanotubes. We describe the application of the same approach to the exfoliation of graphite to give graphene in a range of solvents. When graphite powder is exposed to ultrasonication in the presence of a suitable solvent, the powder fragments into nanosheets, which are stabilized against aggregation by the solvent. The enthalpy of mixing is minimized for solvents with surface energies close to that of graphene (∼68 mJ/m2). The exfoliated nanosheets are free of defects and oxides and can be produced in large quantities. Once solvent exfoliation is possible, the process can be optimized and the nanosheets can be sepd. by size. The use of surfactants can also stabilize exfoliated graphene in water, where the ζ potential of the surfactant-coated graphene nanosheets controls the dispersed concn. Liq. exfoliated graphene can be used for a range of applications: graphene dispersions as optical limiters, films of graphene flakes as transparent conductors or sensors, and exfoliated graphene as a mech. reinforcement for polymer-based composites. Finally, we have extended this process to exfoliate other layered compds. such as BN and MoS2. Such materials will be important in a range of applications from thermoelecs. to battery electrodes. This liq. exfoliation technique can be applied to a wide range of materials and has the potential to be scaled up into an industrial process. We believe the coming decade will see an explosion in the applications involving liq. exfoliated two-dimensional materials.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XktFemur0%253D&md5=d3d0577f3288276a0b9d829cd2fea736
68
Hughes, J. M.; Ahrene, D.; Coleman, J. N. Generalizing Solubility Parameter Theory to Apply to One- and Two-Dimensional Solutes and to Incorporate Dipolar Interactions J. Appl. Polym. Sci. 2013, 127, 4483– 4491 DOI: 10.1002/app.38051

Google Scholar

68
Generalizing solubility parameter theory to apply to one- and two-dimensional solutes and to incorporate dipolar interactions

Hughes, J. Marguerite; Aherne, Damian; Coleman, Jonathan N.

Journal of Applied Polymer Science (2013), 127 (6), 4483-4491CODEN: JAPNAB; ISSN:0021-8995. (John Wiley & Sons, Inc.)

Hildebrand and Hansen soly. parameters are commonly used to identify suitable solvents for the dispersion or dissoln. of a range of solutes, from small mols. to graphene. This practice is based on a no. of equations, which predict the enthalpy of mixing to be minimized when the soly. parameters of solvent and solute match. However, such equations have only been rigorously derived for mixts. of small mols., which interact only via dispersive forces. Herein, we derive a general expression for the enthalpy of mixing in terms of the dimensionality of the solute, where small mols. are considered zero-dimensional, materials such as polymers or nanotubes are one-dimensional (1D) and platelets such as graphene are two-dimensional (2D). We explicitly include contributions due to dispersive, dipole-dipole, and dipole-induced dipole interactions. We find equations very similar to those of Hildebrand and Hansen so long as the soly. parameters of the solute are defined in a manner which reflects their dimensionality. In addn., the equations for 1D and 2D systems are equiv. to known expressions for the enthalpy of mixing of rods and platelets, resp., as a function of surface energy. This agreement between our expressions and those commonly used shows that the concept of soly. parameters can be rigorously applied to extended solutes such as polymers, nanotubes, and graphene. © 2012 Wiley Periodicals, Inc.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XotFynsLw%253D&md5=65196c5f781e7ea40098c1582863e942
69
Nicolosi, V.; Chhowalla, M.; Kanatzidis, M. G.; Strano, M. S.; Coleman, J. N. Liquid Exfoliation of Layered Materials Science 2013, 340, 1226419 DOI: 10.1126/science.1226419

Google Scholar

There is no corresponding record for this reference.
70
Wang, S.; Zhang, Y.; Abidi, N.; Cabrales, L. Wettability and Surface Free Energy of Graphene Films Langmuir 2009, 25, 11078– 11081 DOI: 10.1021/la901402f

Google Scholar

70
Wettability and Surface Free Energy of Graphene Films

Wang, Shiren; Zhang, Yue; Abidi, Noureddine; Cabrales, Luis

Langmuir (2009), 25 (18), 11078-11081CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)

Graphene sheets were produced through chem. exfoliation of natural graphite flake and hydrazine conversion. Subsequently, graphene sheets were assembled into a thin film, and microscale liq. droplets were placed onto the film surface for measurement of wettability and contact angle. It is found that a graphene oxide sheet is hydrophilic and a graphene sheet is hydrophobic. Isolated graphene layers seem more difficult to wet in comparison to graphite, and low adhesion work was found in the graphene-liq. interface. Approxn. of solid-liq. interfacial energy with the equation of state theory was applied to det. the graphene surface energy. The results indicate that surface energy of graphene and graphene oxide is 46.7 and 62.1 mJ/m2, resp., while natural graphite flake shows a surface free energy of 54.8 mJ/m2 at room temp. These results will provide valuable guidance for the design and manufg. of graphene-based biomaterials, medical instruments, structural composites, electronics, and renewable energy devices.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXotlahs7w%253D&md5=7e1575d870b2b887aabaf49fbee386ab
71
Hansen, C. M. Hansen Solubility Parameters: A User’s Handbook, 2nd ed.; CRC Press: New York, 2007.

Google Scholar

There is no corresponding record for this reference.
72
Hansen, C. M. The Three Dimensional Solubility Parameter and Solvent Diffusion Coefficient: Their Importance in Surface Coating Formulation; Danish Technical Press, 1967.
Google Scholar

There is no corresponding record for this reference.
73
Hildebrand, J. H.; Prausnitz, J. M.; Scott, R. L. Regular and Related Solutions: the Solubility of Gases, Liquids, and Solids; van Nostrand Reinhold Co.: New York, 1970.
Google Scholar

There is no corresponding record for this reference.
74
Zhang, Y. H.; Liu, C. J.; Shi, W. Q.; Wang, Z. Q.; Dai, L. M.; Zhang, X. Direct Measurements of the Interaction between Pyrene and Graphite in Aqueous Media by Single Molecule Force Spectroscopy: Understanding the π-π Interactions Langmuir 2007, 23, 7911– 7915 DOI: 10.1021/la700876d

Google Scholar

74
Direct Measurements of the Interaction between Pyrene and Graphite in Aqueous Media by Single Molecule Force Spectroscopy: Understanding the π-π Interactions

Zhang, Yiheng; Liu, Chuanjun; Shi, Weiqing; Wang, Zhiqiang; Dai, Liming; Zhang, Xi

Langmuir (2007), 23 (15), 7911-7915CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)

Pyrene derivs. can absorb onto the surface of carbon nanotubes and graphite particles through π-π interactions to functionalize these inorg. building blocks with org. surface moieties. Using single mol. force spectroscopy, we have demonstrated the first direct measurement of the interaction between pyrene and a graphite surface. In particular, we have connected a pyrene mol. onto an AFM tip via a flexible poly(ethylene glycol) (PEG) chain to ensure the formation of a mol. bridge. The π-π interaction between pyrene and graphite is thus indicated to be ∼55 pN with no hysteresis between the desorption and adhesion forces.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXmvVOkt7Y%253D&md5=44259aa8612e917e70e5c5d7a1870fdc
75
Manohar, S.; Mantz, A. R.; Bancroft, K. E.; Hui, C. Y.; Jagota, A.; Vezenov, D. V. Peeling Single-Stranded DNA from Graphite Surface to Determine Oligonucleotide Binding Energy by Force Spectroscopy Nano Lett. 2008, 8, 4365– 4372 DOI: 10.1021/nl8022143

Google Scholar

75
Peeling Single-Stranded DNA from Graphite Surface to Determine Oligonucleotide Binding Energy by Force Spectroscopy

Manohar, Suresh; Mantz, Amber R.; Bancroft, Kevin E.; Hui, Chung-Yuen; Jagota, Anand; Vezenov, Dmitri V.

Nano Letters (2008), 8 (12), 4365-4372CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

The authors measured the force required to peel single-stranded DNA mols. from single-crystal graphite using chem. force microscopy. Force traces during retraction of a tip chem. modified with oligonucleotides displayed characteristic plateaus with abrupt force jumps, which the authors interpreted as a steady state peeling process punctuated by complete detachment of one or more mols. The authors were able to differentiate between bases in pyrimidine homopolymers; peeling forces were 85.3±4.7 pN for polythymine and 60.8±5.5 pN for polycytosine, substantially independent of salt concn. and the rate of detachment. The authors developed a model for peeling a freely jointed chain from the graphite surface and estd. the av. binding energy per monomer to be 11.5±0.6 kBT and 8.3±0.7 kBT in the cases of thymine and cytosine nucleotides, resp. The equil. free-energy profile simulated using mol. dynamics had a potential well of 18.9 kBT for thymidine, showing that nonelectrostatic interactions dominate the binding. The discrepancy between the expt. and theory indicates that not all bases are adsorbed on the surface or that there is a population of conformations in which they adsorb. Force spectroscopy using oligonucleotides covalently linked to AFM tips provides a flexible and unambiguous means to quantify the strength of interactions between DNA and a no. of substrates, potentially including nanomaterials such as carbon nanotubes.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXhtlCqur7K&md5=75cda9909f155ed374703d821d85967f
76
Georgakilas, V.; Otyepka, M.; Bourlinos, A. B.; Chandra, V.; Kim, N.; Kemp, K. C.; Hobza, P.; Zboril, R.; Kim, K. S. Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications Chem. Rev. 2012, 112, 6156– 6214 DOI: 10.1021/cr3000412

Google Scholar

76
Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications

Georgakilas, Vasilios; Otyepka, Michal; Bourlinos, Athanasios B.; Chandra, Vimlesh; Kim, Namdong; Kemp, K. Christian; Hobza, Pavel; Zboril, Radek; Kim, Kwang S.

Chemical Reviews (Washington, DC, United States) (2012), 112 (11), 6156-6214CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)

This comprehensive review covers all modes and methods of graphene functionalization including their classification. The complementary discussions of both exptl. and theor. aspects of graphene functionalization and interaction is presented. The functionalization modes related to chem. of graphene derivs. (graphene oxide, graphane, fluorographene) represent a significant part of the review, which thus considerably exceeds the chem. of pristine graphene. Both covalent functionalization based on binding of org. functionalities like free radicals and dienophiles on pristine graphene and attachment through the chem. of oxygen groups of graphene oxide are comprehensively discussed. The covalent attachments of hydrogen and halogens and, generally, the chem. of graphane and fluorographene are described. Noncovalent functionalization and interactions, which do not disrupt the extended p-conjugation on the graphene surface unlike covalent functionalization, are discussed. The theory of graphene-ligand non-covalent interactions is presented, while various interaction modes (p interactions) are analyzed from both theor. and exptl. viewpoints. The methods of deposition of various nanostructures on graphene are discussed, including a great variety of nanoparticles like noble metals, metal oxides, quantum dots, polymers, and others. The superior properties and applicability of these graphene-nanoparticle composites are extensively analyzed. The specific methods of graphene doping to control the type and concn. of charged carriers are summarized. Selected applications of functionalized graphene, including doped graphene electronic devices, magnetic bilayer intercalates, electronic/spintronic devices, and DNA sequencing devices, green chem., and bio-imaging, are discussed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhtl2mu7fL&md5=0069788307b69d0290cf24036a9015c4
77
Lee, E. C.; Kim, D.; Jurečka, P.; Tarakeshwar, P.; Hobza, P.; Kim, K. S. Understanding of Assembly Phenomena by Aromatic-Aromatic Interactions: Benzene Dimer and the Substituted Systems J. Phys. Chem. A 2007, 111, 3446– 3457 DOI: 10.1021/jp068635t

Google Scholar

77
Understanding of Assembly Phenomena by Aromatic-Aromatic Interactions: Benzene Dimer and the Substituted Systems

Lee, Eun Cheol; Kim, Dongwook; Jurecka, Petr; Tarakeshwar, P.; Hobza, Pavel; Kim, Kwang S.

Journal of Physical Chemistry A (2007), 111 (18), 3446-3457CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)

Interactions involving arom. rings are important in mol./biomol. assembly and engineering. As a consequence, there have been a no. of investigations on dimers involving benzene or other substituted π systems. In this Feature Article, we examine the relevance of the magnitudes of their attractive and repulsive interaction energy components in governing the geometries of several π-π systems. The geometries and the assocd. binding energies were evaluated at the complete basis set (CBS) limit of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using a least biased scheme for the given data set. The results for the benzene dimer indicate that the floppy T-shaped structure (center-to-center distance: 4.96 Å, with an axial benzene off-centered above the facial benzene) is isoenergetic in zero-point-energy (ZPE) cor. binding energy (D0) to the displaced-stacked structure (vertical interplanar distance: 3.54 Å). However, the T-shaped structure is likely to be slightly more stable (D0 ≈ 2.4-2.5 kcal/mol) if quadruple excitations are included in the coupled cluster calcns. The presence of substituents on the arom. ring, irresp. of their electron withdrawing or donating nature, leads to an increase in the binding energy, and the displaced-stacked conformations are more stabilized than the T-shaped conformers. This explains the wide prevalence of displaced stacked structures in org. crystals. Despite that the dispersion energy is dominating, the substituent as well as the conformational effects are correlated to the electrostatic interaction. This electrostatic origin implies that the substituent effect would be reduced in polar soln., but important in apolar media, in particular, for assembling processes.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXktFegt78%253D&md5=55e2063e88f9f028c005fc78a57f00c0
78
Su, Q.; Pang, S.; Alijani, V.; Li, C.; Feng, X.; Muellen, K. Composites of Graphene with Large Aromatic Molecules Adv. Mater. 2009, 21, 3191– 3195 DOI: 10.1002/adma.200803808

Google Scholar

78
Composites of Graphene with Large Aromatic Molecules

Su, Qi; Pang, Shuping; Alijani, Vajiheh; Li, Chen; Feng, Xinliang; Muellen, Klaus

Advanced Materials (Weinheim, Germany) (2009), 21 (31), 3191-3195CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

We have demonstrated an unprecedented approach to noncovalently functionalized graphene with large arom. donor and acceptor mols., resulting in a novel combination of graphene and nanographene building blocks. By this means, one can effectively stabilize the aq. dispersion of graphene sheets and hence yield monolayer and double-layer graphene sheets on substrates in large quantities. Our results further disclose that the different electronic characteristics of large arom. donor and acceptor mols. enable a rational modification of both the electronic structure and cond. of graphene sheets. Remarkably, the further thermal redn. of graphene sheets accompanied by addnl. thermal reaction of nanographene units leads to a dramatic increase of the cond. As a consequence, the power efficiency is greatly improved using graphene composite film as electrodes in heterojunction solar cells.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtVCgurvP&md5=00b0f407e5a4f72754607c2816fd3328
79
Zhang, X. F.; Liu, S. P.; Shao, X. N. Noncovalent Binding of Xanthene and Phthalocyanine Dyes with Graphene Sheets: The Effect of the Molecular Structure Revealed by a Photophysical Study Spectrochim. Acta, Part A 2013, 113, 92– 99 DOI: 10.1016/j.saa.2013.04.066

Google Scholar

79
Noncovalent binding of xanthene and phthalocyanine dyes with graphene sheets: The effect of the molecular structure revealed by a photophysical study

Zhang, Xian-Fu; Liu, Su-Ping; Shao, Xiao-Na

Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy (2013), 113 (), 92-99CODEN: SAMCAS; ISSN:1386-1425. (Elsevier B.V.)

The fluorescence and absorption properties of several xanthene and phthalocyanine dyes were measured in the presence and absence of chem. derived graphene (CDG) sheets. The interaction of pyronine Y (PYY) with graphene sheets was compared with that of rhodamine 6G (R6G) to reveal the effect of the mol. structure. Although the presence of the perpendicular benzene moiety in a R6G or phthalocyanine mol. does cause the difficulty for forming dye-CDG complex and make CDG less efficient in quenching the fluorescence intensity and shortening the fluorescence lifetime, it does not affect the band position of charge transfer absorption, suggesting that no mol. shape change occurred in a dye mol. caused by the interaction with CDG sheets. The spectroscopic and thermodn. data indicated that the dye-CDG binding is of charge transfer nature, while the dynamic fluorescence quenching is due to photoinduced energy and electron transfer.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtVKnu7zE&md5=1f615c7d709ce4826ae06d024659b5d4
80
Yang, X.; Li, J.; Wen, T.; Ren, X.; Huang, Y.; Wang, X. Adsorption of Naphthalene and Its Derivatives on Magnetic Graphene Composites and the Mechanism Investigation Colloids Surf., A 2013, 422, 118– 125 DOI: 10.1016/j.colsurfa.2012.11.063

Google Scholar

80
Adsorption of naphthalene and its derivatives on magnetic graphene composites and the mechanism investigation

Yang, Xin; Li, Jiaxing; Wen, Tao; Ren, Xuemei; Huang, Yongshun; Wang, Xiangke

Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2013), 422 (), 118-125CODEN: CPEAEH; ISSN:0927-7757. (Elsevier B.V.)

Reduced graphene oxide/iron oxide (GO/FeOFe2O3) composites were prepd. as super adsorbent to adsorb 1-naphthylamine, 1-naphthol and naphthalene with different polaritiy. The adsorption capacity was found in the order of naphthalene < 1-naphthol < 1-naphthylamine. Electron-donor-acceptor (EDA) interaction was proposed to be the primary mechanism for the adsorption of arom. compds., and the adsorption capacity increased with increasing dipole moment. Compared with multi-walled carbon nanotubes/iron oxide (MWCNTs/FeOFe2O3), we found the morphol. of adsorbents played an important role in the adsorption for these arom. compds. Thermodn. expts. further indicated that the adsorption processes were endothermic and spontaneous.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXktFalsbo%253D&md5=763ad52c0b8b5a4f8cd9da45f1efda38
81
Zhang, X. F.; Shao, X. Binding Ability of Different Carbon Nano-Materials with Aromatic Phthalocyanine Molecules: Comparison between Graphene and Graphene Oxide J. Photochem. Photobiol., A 2014, 278, 69– 74 DOI: 10.1016/j.jphotochem.2014.01.001

Google Scholar

81
π-π binding ability of different carbon nano-materials with aromatic phthalocyanine molecules: Comparison between graphene, graphene oxide and carbon nanotubes

Zhang, Xian-Fu; Shao, Xiaona

Journal of Photochemistry and Photobiology, A: Chemistry (2014), 278 (), 69-74CODEN: JPPCEJ; ISSN:1010-6030. (Elsevier B.V.)

The π-π stacking ability of graphene sheets (GS), graphene oxide (GO), and single walled carbon nanotubes (SWCNT) with phthalocyanine (Pc) mols. was studied by the UV-vis absorption, steady state and time-resolved fluorescence spectra. Absorption spectra revealed that strong π-π binding with the Pc ground state (S0) occurred for GS and GO but not for SWCNT, the binding ability is GS » GO » SWCNT. However, when a Pc mol. is photoexcited, fluorescence study shows that the π-π interaction capability is changed to GS » SWCNT » GO. Although SWCNT exhibits low ability to bind Pc S0 state, it strongly interacts with Pc S1 state. The data anal. shows that the dynamic quenching for the nanoscaled carbon quenchers still obeys linear Stern-Volmer relationship, but the static quenching is not linear. An exponential expression is needed to fit the data for GS and SWCNT, which indicates that an effective quenching sphere model is valid for the nanoscaled fluorescence quenchers.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitlSnu74%253D&md5=4f29aaf89cd222872218a33069a65da5
82
Wang, J.; Chen, Z.; Chen, B. Adsorption of Polycyclic Aromatic Hydrocarbons by Graphene and Graphene Oxide Nanosheets Environ. Sci. Technol. 2014, 48, 4817– 4825 DOI: 10.1021/es405227u

Google Scholar

82
Adsorption of Polycyclic Aromatic Hydrocarbons by Graphene and Graphene Oxide Nanosheets

Wang, Jun; Chen, Zaiming; Chen, Baoliang

Environmental Science & Technology (2014), 48 (9), 4817-4825CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)

The adsorption of naphthalene, phenanthrene, and pyrene onto graphene (GNS) and graphene oxide (GO) nanosheets was investigated to probe the potential adsorptive sites and mol. mechanisms. The microstructure and morphol. of GNS and GO were characterized by elemental anal., XPS, FTIR, Raman, SEM, and TEM. Graphene displayed high affinity to the polycyclic arom. hydrocarbons (PAHs), whereas GO adsorption was significantly reduced after oxygen-contg. groups were attached to GNS surfaces. An unexpected peak was found in the curve of adsorption coeffs. (Kd) with the PAH equil. concns. The hydrophobic properties and mol. sizes of the PAHs affected the adsorption of G and GO. The high affinities of the PAHs to GNS are dominated by π-π interactions to the flat surface and the sieving effect of the powerful groove regions formed by wrinkles on GNS surfaces. In contrast, the adsorptive sites of GO changed to the carboxyl groups attaching to the edges of GO because the groove regions disappeared and the polar nanosheet surfaces limited the π-π interactions. The TEM and SEM images initially revealed that after loading with PAH, the conformation and aggregation of GNS and GO nanosheets dramatically changed, which explained the observations that the potential adsorption sites of GNS and GO were unusually altered during the adsorption process.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXltFGltb0%253D&md5=abd6e1601312a6c861b1799cf4facbcb
83
Chen, I. W. P.; Huang, C. Y.; Jhou, S. H. S.; Zhang, Y. W. Exfoliation and Performance Properties of Non-Oxidized Graphene in Water Sci. Rep. 2014, 4, 3928 DOI: 10.1038/srep03928

Google Scholar

83
Exfoliation and Performance Properties of Non-Oxidized Graphene in Water

Chen, I.-Wen Peter; Huang, Chun-Yuan; Saint Jhou, Sheng-Hong; Zhang, Yu-Wei

Scientific Reports (2014), 4 (), 3928/1-3928/6CODEN: SRCEC3; ISSN:2045-2322. (Nature Publishing Group)

Single-layered graphene has unique electronic, chem., and electromech. properties. Recently, graphite exfoliation in N-methylpyrrolidone and molten salt has been demonstrated to generate monolayer exfoliated graphene sheets (EGS). However, these solvents are either high-priced or require special care and have high b.ps. and viscosities, making it difficult to deposit the dispersed graphene onto substrates. Here we show a universal principle for the exfoliation of graphite in water to single-layered and several-layered graphene sheets via the direct exfoliation of highly oriented pyrolytic graphite (HOPG) using pyridinium tribromide (Py+Br3-). Elec. cond. >5100 S/cm was obsd. for filtered graphene paper, and the EGS exhibited superior performance as a hole transport layer compared to the conventional material N,N-di(naphthalene-1-yl)-N,N-diphenylbenzidine at low voltage. The overall results demonstrate that this method is a scalable process for the prepn. of highly conductive graphene for use in the com. manuf. of high-performance electronic devices.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXlsVCjur0%253D&md5=4590fbd62e9af77391cdc2b2318e24eb
84
Bourlinos, A. B.; Georgakilas, V.; Zboril, R.; Steriotis, T. A.; Stubos, A. K. Liquid-Phase Exfoliation of Graphite towards Solubilized Graphenes Small 2009, 5, 1841– 1845 DOI: 10.1002/smll.200900242

Google Scholar

84
Liquid-Phase Exfoliation of Graphite Towards Solubilized Graphenes

Bourlinos, Athanasios B.; Georgakilas, Vasilios; Zboril, Radek; Steriotis, Theodore A.; Stubos, Athanasios K.

Small (2009), 5 (16), 1841-1845CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)

This paper describes a neoteric set of solvents for the liq.-phase exfoliation of graphite towards solubilized graphenes. The proposed solvents belong to a peculiar class of perfluorinated arom. mols. and include hexafluorobenzene, octafluorotoluene, pentafluorobenzonitrile, and pentafluoropyridine. Complementary to these liqs., blank expts. with the related hydrocarbon analogs unexpectedly led to the notable case of pyridine. Along with these solvents, an assortment of other suitable dispersing media is cited in parallel. The conversion of the as-derived single sheets into metal-graphene hybrids is also presented.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXps1yku74%253D&md5=525ab89601b8b5fedffa1f97f672eee0
85
Kim, J.; Song, S. H.; Im, H. G.; Yoon, G.; Lee, D.; Choi, C.; Kim, J.; Bae, B. S.; Kang, K.; Jeon, S. Moisture Barrier Composites Made of Non-Oxidized Graphene Flakes Small 2015, 11, 3124– 3129 DOI: 10.1002/smll.201403647

Google Scholar

85
Moisture Barrier Composites Made of Non-Oxidized Graphene Flakes

Kim, Jungmo; Song, Sung Ho; Im, Hyeon-Gyun; Yoon, Gabin; Lee, Dongju; Choi, Chanyong; Kim, Jin; Bae, Byeong-Soo; Kang, Kisuk; Jeon, Seokwoo

Small (2015), 11 (26), 3124-3129CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)

We demonstrate improved moisture barrier property of polyethylene (PE) composite, approaching the theor. value, by incorporating low-defect-content non-oxidized graphene flakes (NOGFs). The fabrication of NOGFs in micrometer scale (>1 μm) and their functionalization were simultaneously achieved by introducing solvothermal intercalation of an org. solvent, quinoline. Partial intercalation of quinoline mols. promoted exfoliation efficiency by lowering the interlayer binding energy of graphite by 30 meV, calcd. from d. functional theory (DFT)-based simulations. Compared to NOGFs produced solely from sonication, the produced NOGFs had increased av. size while exhibiting high crystallinity and extremely low oxidn., comparable to that of source graphite. Moreover, the conjugated nature of quinoline resulted in stable non-covalent functionalization of the NOGFs whose zeta potential is -20 mV, large enough for uniform dispersion with increased hydrophobicity in the matrix polymer. The low-defect NOGFs with minimal oxidn. and high hydrophobicity are ideal as nanofillers for moisture barrier composites. The water vapor transmission rate (WVTR) of polyethylene (PE)-NOGF composite film with a 1 wt% loading compared to the pristine PE film and the PE-GO composite film of similar loading showed a redn. of the WVTR of 58% and 37.5%, resp. The measured WVTR value of PE-NOGF was 1.2 x 10-1 g.m-2.day-1, which is an order of magnitude lower than the previously reported value for polymer-graphene composites.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXkvF2ktbo%253D&md5=b42538390e3f76d134c67f3cef47ce4b
86
Lee, D. W.; Kim, T.; Lee, M. An Amphiphilic Pyrene Sheet for Selective Functionalization of Graphene Chem. Commun. 2011, 47, 8259– 8261 DOI: 10.1039/c1cc12868j

Google Scholar

86
An amphiphilic pyrene sheet for selective functionalization of graphene

Lee, Dong-Woo; Kim, Taehoon; Lee, Myongsoo

Chemical Communications (Cambridge, United Kingdom) (2011), 47 (29), 8259-8261CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)

It was demonstrated that the arom. amphiphile consisting of a hydrophilic dendron and an arom. segment with a planar conformation can selectively exfoliate graphite powder into single- and double-layer graphene sheets in aq. soln. through hydrophilic functionalization of graphene surfaces.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXoslajt7Y%253D&md5=5cd156fef0aca70ab39d7b693b9e96cd
87
Yang, H.; Hernandez, Y.; Schlierf, A.; Felten, A.; Eckmann, A.; Johal, S.; Louette, P.; Pireaux, J. J.; Feng, X.; Muellen, K. A Simple Method for Graphene Production Based on Exfoliation of Graphite in Water Using 1-Pyrenesulfonic Acid Sodium Salt Carbon 2013, 53, 357– 365 DOI: 10.1016/j.carbon.2012.11.022

Google Scholar

87
A simple method for graphene production based on exfoliation of graphite in water using 1-pyrenesulfonic acid sodium salt

Yang, H.; Hernandez, Y.; Schlierf, A.; Felten, A.; Eckmann, A.; Johal, S.; Louette, P.; Pireaux, J.-J.; Feng, X.; Mullen, K.; Palermo, V.; Casiraghi, C.

Carbon (2013), 53 (), 357-365CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

A chem. approach was used based on supramol. and non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py-1SO3) to obtain a stable dispersion of graphene by only water as solvent. The material was characterized by a combination of spectroscopic and microscopic techniques. In particular, an extensive Raman anal. shows that ≈70% have few-graphene layers (<7). The exfoliation efficiency strongly depends on the no. of functional groups by comparing suspensions obtained by Py-1SO3 and 1,3,6,8-pyrenetetrasulfonic acid (Py-4SO3). A strong decrease in the exfoliation yield was obsd. by pyrene with 4 sulfonic groups (Py-4SO3), as compared to one sulfonic group (Py-1SO3). Being completely water-based, these suspensions can be used as inks for printable tattoo-based electrochem. sensors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhslOjtbjI&md5=f786c844804953f06f086871bf31b6e2
88
Jang, J. H.; Rangappa, D.; Kwon, Y. U.; Honma, I. Direct Preparation of 1-PSA Modified Graphene Nanosheets by Supercritical Fluidic Exfoliation and Its Electrochemical Properties J. Mater. Chem. 2011, 21, 3462– 3466 DOI: 10.1039/C0JM02472D

Google Scholar

There is no corresponding record for this reference.
89
An, X. H.; Simmons, T. J.; Shah, R.; Wolfe, C.; Lewis, K. M.; Washington, M.; Nayak, S. K.; Talapatra, S.; Kar, S. Stable Aqueous Dispersions of Noncovalently Functionalized Graphene from Graphite and their Multifunctional High-Performance Applications Nano Lett. 2010, 10, 4295– 4301 DOI: 10.1021/nl903557p

Google Scholar

89
Stable Aqueous Dispersions of Noncovalently Functionalized Graphene from Graphite and their Multifunctional High-Performance Applications

An, Xiaohong; Simmons, Trevor; Shah, Rakesh; Wolfe, Christopher; Lewis, Kim M.; Washington, Morris; Nayak, Saroj K.; Talapatra, Saikat; Kar, Swastik

Nano Letters (2010), 10 (11), 4295-4301CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

We present a scalable and facile technique for noncovalent functionalization of graphene with 1-pyrenecarboxylic acid that exfoliates single-, few-, and multilayered graphene flakes into stable aq. dispersions. The exfoliation mechanism is established using stringent control expts. and detailed characterization steps. Using the exfoliated graphene, we demonstrate highly sensitive and selective conductometric sensors (whose resistance rapidly changes >10,000% in satd. ethanol vapor), and ultracapacitors with extremely high specific capacitance (∼120 F/g), power d. (∼105 kW/kg), and energy d. (∼9.2 Wh/kg).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXns1Wru7w%253D&md5=140b93a45ebef632706a8c271c2f65c7
90
Dong, X. C.; Shi, Y. M.; Zhao, Y.; Chen, D. M.; Ye, J.; Yao, Y. G.; Gao, F.; Ni, Z. H.; Yu, T.; Shen, Z. X. Symmetry Breaking of Graphene Monolayers by Molecular Decoration Phys. Rev. Lett. 2009, 102, 135501 DOI: 10.1103/PhysRevLett.102.135501

Google Scholar

90
Symmetry Breaking of Graphene Monolayers by Molecular Decoration

Dong, Xiaochen; Shi, Yumeng; Zhao, Yang; Chen, Dongmeng; Ye, Jun; Yao, Yugui; Gao, Fang; Ni, Zhenhua; Yu, Ting; Shen, Zexiang; Huang, Yinxi; Chen, Peng; Li, Lain-Jong

Physical Review Letters (2009), 102 (13), 135501/1-135501/4CODEN: PRLTAO; ISSN:0031-9007. (American Physical Society)

Arom. mols. can effectively exfoliate graphite into graphene monolayers, and the resulting graphene monolayers sandwiched by the arom. mols. exhibit a pronounced Raman G-band splitting, similar to that obsd. in single-walled carbon nanotubes. Raman measurements and calcns. based on the force-const. model demonstrate that the absorbed arom. mols. are responsible for the G-band splitting by removing the energy degeneracy of in-plane longitudinal and transverse optical phonons at the Γ point.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXktV2qtLg%253D&md5=6c35ec693586296313caa33bb30b4b6d
91
Zhang, M.; Parajuli, R. R.; Mastrogiovanni, D.; Dai, B.; Lo, P.; Cheung, W.; Brukh, R.; Chiu, P. L.; Zhou, T.; Liu, Z. F. Production of Graphene Sheets by Direct Dispersion with Aromatic Healing Agents Small 2010, 6, 1100– 1107 DOI: 10.1002/smll.200901978

Google Scholar

91
Production of Graphene Sheets by Direct Dispersion with Aromatic Healing Agents

Zhang, Ming; Parajuli, Rishi R.; Mastrogiovanni, Daniel; Dai, Boya; Lo, Phil; Cheung, William; Brukh, Roman; Chiu, Pui Lam; Zhou, Tao; Liu, Zhongfan; Garfunkel, Eric; He, Huixin

Small (2010), 6 (10), 1100-1107CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)

A simple and scalable exfoliation approach was developed to produce high-quality single-layer graphene sheets (rather than nonconductive graphene oxide (GO)) in one step, which can be used to fabricate transparent conductive films. Compared to the traditional GO approach to produce conductive graphene sheets, there is no oxidn. and redn. reaction of GO involved. The proposed method decreases the no. of prepn. steps and significantly shortens the prodn. time. In a typical exptl. procedure, graphite powders were exfoliated in a water soln. of pyrene derivs. with the help of sonication. The pyrene derivs. acted as dispersion agents during the exfoliation process and also acted as healing agents and elec. 'glue' during the thermal annealing process. Transparent conductive films fabricated with this approach exhibit a cond. of 181200 S/m (sheet resistance of 778 Ω per square with 90% light transmittance in the 400-800nm wavelength range), the best to date of which we are aware. Transparent conductive graphene films are promising candidates to replace transparent conductive oxides (TCOs) for photovoltaic (PV)/solar cell applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXmsFylurc%253D&md5=543ab8be5a90dc6f9144db794824b734
92
Schlierf, A.; Yang, H.; Gebremedhn, E.; Treossi, E.; Ortolani, L.; Chen, L.; Minoia, A.; Morandi, V.; Samori, P.; Casiraghi, C. Nanoscale Insight into the Exfoliation Mechanism of Graphene with Organic Dyes: Effect of Charge, Dipole and Molecular Structure Nanoscale 2013, 5, 4205– 4216 DOI: 10.1039/c3nr00258f

Google Scholar

92
Nanoscale insight into the exfoliation mechanism of graphene with organic dyes: effect of charge, dipole and molecular structure

Schlierf, Andrea; Yang, Huafeng; Gebremedhn, Elias; Treossi, Emanuele; Ortolani, Luca; Chen, Liping; Minoia, Andrea; Morandi, Vittorio; Samori, Paolo; Casiraghi, Cinzia; Beljonne, David; Palermo, Vincenzo

Nanoscale (2013), 5 (10), 4205-4216CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

We study the mechanism of surface adsorption of org. dyes on graphene, and successive exfoliation in water of these dye-functionalized graphene sheets. A systematic, comparative study is performed on pyrenes functionalized with an increasing no. of sulfonic groups. By combining exptl. and modeling investigations, we find an unambiguous correlation between the graphene-dye interaction energy, the mol. structure and the amt. of graphene flakes solubilized. The results obtained indicate that the mol. dipole is not important per se, but because it facilitates adsorption on graphene by a "sliding" mechanism of the mol. into the solvent layer, facilitating the lateral displacement of the water mols. collocated between the arom. cores of the dye and graphene. While a large dipole and mol. asymmetry promote the adsorption of the mol. on graphene, the stability and pH response of the suspensions obtained depend on colloidal stabilization, with no significant influence of mol. charging and dipole.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXmvFOqsL8%253D&md5=e21a4ce567c3f6f2e3d5b729c8d76bfb
93
Song, S. H.; Park, K. H.; Kim, B. H.; Choi, Y. W.; Jun, G. H.; Lee, D. J.; Kong, B. S.; Paik, K. W.; Jeon, S. Enhanced Thermal Conductivity of Epoxy–Graphene Composites by Using Non-Oxidized Graphene Flakes with Non-Covalent Functionalization Adv. Mater. 2013, 25, 732– 737 DOI: 10.1002/adma.201202736

Google Scholar

93
Enhanced Thermal Conductivity of Epoxy-Graphene Composites by Using Non-Oxidized Graphene Flakes with Non-Covalent Functionalization

Song, Sung Ho; Park, Kwang Hyun; Kim, Bo Hyun; Choi, Yong Won; Jun, Gwang Hoon; Lee, Dong Ju; Kong, Byung-Seon; Paik, Kyung-Wook; Jeon, Seokwoo

Advanced Materials (Weinheim, Germany) (2013), 25 (5), 732-737CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

This work suggests a method for obtaining noncovalently functionalized graphene flakes with 1-pyrenebutyric acid that are high sol. in various solvents and these graphene flakes are used to synthesize an epoxy-graphene composite showing enhanced thermal cond.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1OgtrfK&md5=3423bd3ed4fa2dbdc416cc254983e865
94
Khanra, P.; Uddin, M. E.; Kim, N. H.; Kuila, T.; Lee, S. H.; Lee, J. H. Electrochemical Performance of Reduced Graphene Oxide Surface-Modified with 9-Anthracene Carboxylic Acid RSC Adv. 2015, 5, 6443– 6451 DOI: 10.1039/C4RA12356E

Google Scholar

94
Electrochemical performance of reduced graphene oxide surface-modified with 9-anthracene carboxylic acid

Khanra, Partha; Uddin, Md. Elias; Kim, Nam Hoon; Kuila, Tapas; Lee, Seung Hee; Lee, Joong Hee

RSC Advances (2015), 5 (9), 6443-6451CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

An efficient approach for the prepn. of 9-anthracene carboxylic acid (ACA) modified reduced graphene oxide (rGO) was demonstrated in this study. ACA was used as a surface-modifying agent and underwent a reversible redox reaction. The benzene ring of the ACA anion was attached to the rGO surface via π-π interactions, and the carboxylate anions helped to disperse the hybrid materials in water due to hydrogen bonding. Therefore, water-dispersible, ACA-modified rGO (ACA-rGO) improved the wettability and capacitance performance in aq. electrolyte solns. The morphol. of the ACA-rGO was studied using transmission electron microscopy and at. force microscopy image anal. The dispersion characteristics of the exfoliated materials were investigated using UV-vis spectroscopy anal. The chem. states and natures of the samples were investigated using Fourier-transform IR spectroscopy and XPS. The appearance of a new peak at 288.7 eV in the XPS of ACA-rGO confirmed the successful surface modification of rGO using ACA. Raman spectra were studied to compare the electronic structure and defect concns. in the ACA-rGO with respect to GO. The low intensity and shifted D- and G-bands indicated non-covalent functionalization of rGO with ACA anions. Electrochem. performances of ACA-rGO, rGO, and GO were evaluated in 1 M aq. Na2SO4 electrolyte. The capacitance performance was investigated through galvanometric charge-discharge with ACA-rGO, rGO, and GO in an operating voltage of -1 to 1 V. The range of specific capacitance in the three-electrode system was 610 to 115 F g-1 at a c.d. range of 0.8 to 20 A g-1. In addn., the capacitance performance of ACA-rGO was studied in 1 M Na2SO4 electrolyte using two-electrode systems. The cell capacitance, energy d., and power d. at a c.d. of 0.2 A g-1 of the asym. assembly with multiwall carbon nanotubes were 77 F g-1, 41.3 Wh kg-1, and 200 W kg-1, resp.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFegsL7M&md5=9a8efbfa982e4b237a1418909d127dec
95
Bose, S.; Kuila, T.; Mishra, A. K.; Kim, N. H.; Lee, J. H. Preparation of Non-Covalently Functionalized Graphene Using 9-Anthracene Carboxylic Acid Nanotechnology 2011, 22, 405603 DOI: 10.1088/0957-4484/22/40/405603

Google Scholar

There is no corresponding record for this reference.
96
Das, S.; Irin, F.; Ahmed, H. S. T.; Cortinas, A. B.; Wajid, A. S.; Parviz, D.; Jankowski, A. F.; Kato, M.; Green, M. J. Non-Covalent Functionalization of Pristine Few-Layer Graphene Using Triphenylene Derivatives for Conductive Poly (Vinyl Alcohol) Composites Polymer 2012, 53, 2485– 2494 DOI: 10.1016/j.polymer.2012.03.012

Google Scholar

96
Non-covalent functionalization of pristine few-layer graphene using triphenylene derivatives for conductive poly(vinyl alcohol) composites

Das, Sriya; Irin, Fahmida; Tanvir Ahmed, H. S.; Cortinas, Abel B.; Wajid, Ahmed S.; Parviz, Dorsa; Jankowski, Alan F.; Kato, Masaru; Green, Micah J.

Polymer (2012), 53 (12), 2485-2494CODEN: POLMAG; ISSN:0032-3861. (Elsevier Ltd.)

In this paper, we demonstrate a facile technique to disperse pristine few-layer graphene (FLG) in water utilizing a triphenylene based stabilizer (C10) that non-covalently functionalizes the surface without micelle formation. The yield of FLG in the final dispersion (0.2 mg FLG/mg C10) is much higher than comparable surfactants and polymers stabilizers. This dispersion is reversible in response to pH changes unlike conventional stabilizers. The C10-stabilized FLG dispersion is also stable against heat and lyophilization. This non-covalent functionalization does not disrupt the pristine structure of the graphene sheets; instead, these coatings allow for stable, aggregation-resistant FLG dispersion, as characterized through TEM. To demonstrate the utility of such dispersions, we prepd. pristine FLG-loaded poly (vinyl alc.) (PVA) composites by a simple soln. casting process. This is the first example of PVA composites based on pristine graphene. These composites have enhanced elec. properties at relatively low filler fraction (0.26 vol% FLG). Moreover, these composites exhibit improved mech. properties established by tensile and hardness tests results; these data suggest anisotropic reinforcement caused by graphene alignment.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XmtFertrg%253D&md5=761d553e5214605b161560a9617e446e
97
Ghosh, A.; Rao, K. V.; George, S. J.; Rao, C. N. R. Noncovalent Functionalization, Exfoliation, and Solubilization of Graphene in Water by Employing a Fluorescent Coronene Carboxylate Chem. - Eur. J. 2010, 16, 2700– 2704 DOI: 10.1002/chem.200902828

Google Scholar

97
Noncovalent Functionalization, Exfoliation, and Solubilization of Graphene in Water by Employing a Fluorescent Coronene Carboxylate

Ghosh, Anupama; Rao, K. Venkata; George, Subi J.; Rao, C. N. R.

Chemistry - A European Journal (2010), 16 (9), 2700-2704, S2700/1-S2700/6CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)

We have demonstrated a simple and efficient method to make stable aq. soln. of graphenes. This is by exploiting noncovalent interactions with a coronene carboxylate acceptor mol. Optical and Raman spectroscopy shows the strong mol. charge transfer interaction with the graphene.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXislKnsL8%253D&md5=df14372ad87d9a666d1621040551456a
98
Ma, W. S.; Wu, L.; Yang, F.; Wang, S. F. Non-Covalently Modified Reduced Graphene Oxide/Polyurethane Nanocomposites with Good Mechanical and Thermal Properties J. Mater. Sci. 2014, 49, 562– 571 DOI: 10.1007/s10853-013-7736-4

Google Scholar

98
Non-covalently modified reduced graphene oxide/polyurethane nanocomposites with good mechanical and thermal properties

Ma, Wen-Shi; Wu, Li; Yang, Fang; Wang, Shuang-Feng

Journal of Materials Science (2014), 49 (2), 562-571CODEN: JMTSAS; ISSN:0022-2461. (Springer)

Non-covalently modified graphene nanosheets were prepd. by redn. graphene oxide with hydrazine hydrate and simultaneous non-covalent functionalization via 1-allyl-methylimidazolium chloride (AmimCl) ionic liq. Atomic force microscopy revealed that AmimCl ionic liq. modified graphene (IL-G) was well-dispersed in a single exfoliation with a thickness of around 0.96 nm in DMF. Subsequently, the prepd. IL-G nanosheets were incorporated into polyurethane (PU) to fabricate IL-G/PU nanocomposites by soln. blending. X-ray diffraction disclosed an exfoliated morphol. of IL-G nanosheets dispersed in the PU matrix, while the fractured morphol. of the IL-G/PU nanocomposites showed that IL-G nanosheets presented a wrinkled morphol. when dispersed in the matrix. Both techniques revealed homogeneous dispersion and good compatibility of IL-G nanosheets with PU matrix, indicating the existence of interfacial interactions. At 0.608 wt% loadings of IL-G nanosheets, the tensile strength and storage modulus of the composites were increased by 68.5 and 81.1 %, resp. High thermal properties were also achieved at a low loading of IL-G nanosheets. An approx. 40 °C improvement in temp. of 5 % wt. loss and 34 % increase in thermal cond. were obtained at just 0.608 wt% loading of IL-G nanosheets.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsVymsr3O&md5=49efb2f21f4b6d532f3367f23524f89a
99
Lonkar, S. P.; Bobenrieth, A.; De Winter, J.; Gerbaux, P.; Raquez, J. M.; Dubois, P. A Supramolecular Approach toward Organo-Dispersible Graphene and Its Straightforward Polymer Nanocomposites J. Mater. Chem. 2012, 22, 18124– 18126 DOI: 10.1039/c2jm34234k

Google Scholar

There is no corresponding record for this reference.
100
Yang, Y. K.; He, C. E.; Peng, R. G.; Baji, A.; Du, X. S.; Huang, Y. L.; Xie, X. L.; Mai, Y. W. Non-Covalently Modified Graphene Sheets by Imidazolium Ionic Liquids for Multifunctional Polymer Nanocomposites J. Mater. Chem. 2012, 22, 5666– 5675 DOI: 10.1039/c2jm16006d

Google Scholar

100
Non-covalently modified graphene sheets by imidazolium ionic liquids for multifunctional polymer nanocomposites

Yang, Ying-Kui; He, Cheng-En; Peng, Ren-Gui; Baji, Avinash; Du, Xu-Sheng; Huang, Yuan-Li; Xie, Xiao-Lin; Mai, Yiu-Wing

Journal of Materials Chemistry (2012), 22 (12), 5666-5675CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)

Chem. redn. of graphite oxide (GO) to produce graphene nanosheets often results in irreversible agglomeration and pptn. Herein, stable well-dispersed graphene sheets in solvents were obtained by simultaneous functionalization and redn. of GO under alk. conditions, in the presence of sodium borohydride and imidazolium ionic liqs. (Imi-ILs) contg. two vinyl-benzyl groups. In this case, pos. charged imidazolium groups of Imi-ILs underwent ion-exchange with neg. charged GO sheets and were linked to their edges, while Imi-ILs were non-covalently attached onto the large surfaces of graphene through π-π and/or cation-π stacking interactions. The vinyl-benzyl reactive sites were then copolymd. in situ with Me methacrylate to fabricate graphene/poly(Me methacrylate) (PMMA) composites. Functionalized graphene sheets were uniformly dispersed in the PMMA matrix and contributed to large increases in storage modulus (+58.3%) and glass transition temp. (+19.2 °C) at 2.08 vol.% loading. High elec. cond. was also achieved at graphene loading levels beyond 1 vol.% (ca. 2.55 Sm-1) with a low percolation threshold (0.25 vol.%) for the composites. Hence, a general methodol. which facilitates the development of a multifunctional advanced material has been successfully established. This can be extended to other vinyl polymer-based composites contg. graphene.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XjtVGms7g%253D&md5=109f62d73d0f22818673ebc89ee9d95f
101
Bari, R.; Tamas, G.; Irin, F.; Aquino, A. J. A.; Green, M. J.; Quitevis, E. L. Direct Exfoliation of Graphene in Ionic Liquids with Aromatic Groups Colloids Surf., A 2014, 463, 63– 69 DOI: 10.1016/j.colsurfa.2014.09.024

Google Scholar

101
Direct exfoliation of graphene in ionic liquids with aromatic groups

Bari, Rozana; Tamas, George; Irin, Fahmida; Aquino, Adelia J. A.; Green, Micah J.; Quitevis, Edward L.

Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2014), 463 (), 63-69CODEN: CPEAEH; ISSN:0927-7757. (Elsevier B.V.)

Novel ionic liqs. (ILs) were designed and synthesized to contain arom. groups on the imidazolium cation that non-covalently interact with graphene surfaces. This route enables the dispersion of pristine graphene without covalent functionalization or an additive stabilizer; such dispersions are stable against aggregation and display high concn. values. We find that ILs without these arom. groups are less effective in graphene dispersion, and the dispersed graphene concn. increases with increasing interaction between the cation and graphene surface. D. functional theory (DFT-D3) calcns. support the exptl. observations and provide a foundation for predictive modeling of IL design for optimal graphene dispersions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1ems7rM&md5=3676b4f736299be01f7b850163901dae
102
Zhang, B.; Ning, W.; Zhang, J.; Qiao, X.; Zhang, J.; He, J.; Liu, C. Y. Stable Dispersions of Reduced Graphene Oxide in Ionic Liquids J. Mater. Chem. 2010, 20, 5401– 5403 DOI: 10.1039/c0jm01029d

Google Scholar

102
Stable dispersions of reduced graphene oxide in ionic liquids

Zhang, Baoqing; Ning, Wei; Zhang, Jinming; Qiao, Xin; Zhang, Jun; He, Jiasong; Liu, Chen-Yang

Journal of Materials Chemistry (2010), 20 (26), 5401-5403CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)

Starting with graphene oxide, the authors successfully prepd. stable dispersions of reduced graphene oxide (RGO) in three hydrophilic ionic liqs. (ILs) at relatively high concn. without using any surfactants/stabilizers.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXnslyqurk%253D&md5=d9dd76e378b766fdd8af901c16e07da1
103
Kim, T. Y.; Lee, H. W.; Kim, J. E.; Suh, K. S. Synthesis of Phase Transferable Graphene Sheets Using Ionic Liquid Polymers ACS Nano 2010, 4, 1612– 1618 DOI: 10.1021/nn901525e

Google Scholar

103
Synthesis of phase transferable graphene sheets using ionic liquid polymers

Kim, TaeYoung; Lee, HyunWook; Kim, JongEun; Suh, Kwang S.

ACS Nano (2010), 4 (3), 1612-1618CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

A practical route to the prodn. of soln. phase transferable graphene sheets using ionic liq. polymers (PIL) as a transferring medium is developed. Chem. converted graphene sheets decorated with PIL were found to be stable against the chem. redn. and well dispersed in the aq. phase without any agglomeration. Upon the anion exchange of the PIL on graphene sheets, these PIL-modified graphene sheets in aq. phase are readily transferred into the org. phase by changing their properties from hydrophilic to hydrophobic.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhvF2ks7k%253D&md5=aa1088c64b0f360fb050000cbb466fae
104
Geng, J.; Jung, H. T. Porphyrin Functionalized Graphene Sheets in Aqueous Suspensions: From the Preparation of Graphene Sheets to Highly Conductive Graphene Films J. Phys. Chem. C 2010, 114, 8227– 8234 DOI: 10.1021/jp1008779

Google Scholar

104
Porphyrin Functionalized Graphene Sheets in Aqueous Suspensions: From the Preparation of Graphene Sheets to Highly Conductive Graphene Films

Geng, Jianxin; Jung, Hee-Tae

Journal of Physical Chemistry C (2010), 114 (18), 8227-8234CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)

Graphene has a unique structure and potential applications in nanoelectronics, nanocomposites, conductive and transparent films, etc. Synthesis of graphene is one of the major research efforts to make rapid developments in graphene research. A new method, that makes use of the π-π interactions between porphyrin and graphene to stabilize the chem. converted graphene (CCG), was developed for prepn. of CCG via chem. redn. of exfoliated graphene oxide (GO). Optical absorption spectroscopy measurement shows that π-π interactions take place between GO and porphyrins, 5,10,15,20-tetraphenyl-21H, 23H-porphine-p,p',p'',p'''-tetrasulfonic acid tetrasodium hydrate (TPP-SO3Na) and 5,10,15,20-tetrakis(4-trimethylammoniophenyl) porphyrin tetra(p-toluenesulfonate). TPP-SO3Na functionalized CCG can form a stable aq. suspension due to the electrostatic repulsion between the CCG sheets, which results from the aggregation of TPP-SO3Na mols. on the surfaces of the CCG sheets. Atomic force microscope observation shows that the TPP-SO3Na functionalized CCG sheets are single-layer entities, which are sandwiched by TPP-SO3Na mols. Conductive graphene films with various thicknesses were prepd. by using the TPP-SO3Na functionalized CCG suspension via a vacuum filtration method. The change of the sheet resistance of the CCG films follows the percolation mechanism. A sheet resistance as low as ∼5 KΩ·-1 of the CCG films with 80% transparency at 550 nm was obtained. Such low sheet resistance is contributed to improved sp2 networks of the CCG sheets, low contact resistance between the CCG sheets, and the healing of the defective vacancies on CCG sheets by porphyrin mols., which are achieved by combination of chem. redn. of GO and thermal annealing of the resultant CCG films.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXkslKluro%253D&md5=1ded06b2409be43e61b84a4b8a32ecdb
105
Xu, Y.; Zhao, L.; Bai, H.; Hong, W.; Li, C.; Shi, G. Chemically Converted Graphene Induced Molecular Flattening of 5,10,15,20-Tetrakis(1-methyl-4-pyridinio)porphyrin and Its Application for Optical Detection of Cadmium(II) Ions J. Am. Chem. Soc. 2009, 131, 13490– 13497 DOI: 10.1021/ja905032g

Google Scholar

105
Chemically Converted Graphene Induced Molecular Flattening of 5,10,15,20-Tetrakis(1-methyl-4-pyridinio)porphyrin and Its Application for Optical Detection of Cadmium(II) Ions

Xu, Yuxi; Zhao, Lu; Bai, Hua; Hong, Wenjing; Li, Chun; Shi, Gaoquan

Journal of the American Chemical Society (2009), 131 (37), 13490-13497CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

Complexation of cationic 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin (TMPyP) and neg. charged chem. converted graphene (CCG) sheets was performed by simply mixing the dild. aq. solns. of both components. During this process, a large bathochromic shift of porphyrin Soret band from 421 to 458 nm was obsd., which is attributed to the flattening of TMPyP mols. induced by CCG through electrostatic and π-π stacking cooperative interactions. Also, the coordination reaction between TMPyP and Cd2+ ions was greatly accelerated from 20 h to 8 min under ambient conditions by introducing CCG sheets. From this phenomenon, the authors used the complex of TMPyP and CCG as an optical probe for rapid and selective detection of Cd2+ ions in aq. media.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtVGgu77E&md5=ac3eda034fdeb89671b9a4336de7f041
106
Arramel, A.; Castellanos-Gomez, B.; van Wees, J. Band Gap Opening of Graphene by Noncovalent π-π Interaction with Porphyrins Graphene 2013, 2, 102– 108 DOI: 10.4236/graphene.2013.23015

Google Scholar

There is no corresponding record for this reference.
107
Bozkurt, E.; Acar, M.; Onganer, Y.; Meral, K. Rhodamine 101-Graphene Oxide Composites in Aqueous Solution: the Fluorescence Quenching Process of Rhodamine 101 Phys. Chem. Chem. Phys. 2014, 16, 18276– 18281 DOI: 10.1039/C4CP01492H

Google Scholar

There is no corresponding record for this reference.
108
Jiang, B. P.; Hu, L. F.; Wang, D. J.; Ji, S. C.; Shen, X. C.; Liang, H. Graphene Loading Water-Soluble Phthalocyanine for Dual-Modality Photothermal/Photodynamic Therapy via a One-Step Method J. Mater. Chem. B 2014, 2, 7141– 7148 DOI: 10.1039/C4TB01038H

Google Scholar

108
Graphene loading water-soluble phthalocyanine for dual-modality photothermal/photodynamic therapy via a one-step method

Jiang, Bang-Ping; Hu, Lan-Fang; Wang, Dong-Jin; Ji, Shi-Chen; Shen, Xing-Can; Liang, Hong

Journal of Materials Chemistry B: Materials for Biology and Medicine (2014), 2 (41), 7141-7148CODEN: JMCBDV; ISSN:2050-7518. (Royal Society of Chemistry)

In this paper, we present a new and facile one-step method for the fabrication of a water-sol. graphene-phthalocyanine (GR-Pc) hybrid material by simply sonicating GR with a hydrophilic Pc, tetrasulfonic acid tetrasodium salt copper phthalocyanine (TSCuPc). In the resultant hybrid material, TSCuPc is coated on the skeleton of pristine GR via non-covalently π-π interaction, detailedly characterized by UV-vis/Raman spectra, XPS, etc. The obtained GR-Pc hybrid (GR-TSCuPc) is applied for photothermal therapy (PTT) and photodynamic therapy (PDT). In this PTT/PDT system, both GR and TSCuPc operate as multifunctional agents: GR acts as a photosensitizer carrier and PTT agent, while TSCuPc acts as a hydrophilic PDT agent. Furthermore, the results of cell viability show that the phototherapy effect of GR-TSCuPc is observably higher than that of free TSCuPc, indicating that combined noninvasive PTT/PDT exhibits better anti-cancer efficacy in vitro. Such results highlight that this work provide a facile method to develop efficacious dual-modality carbon nanoplatform for developing cancer therapeutics.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVSiu7nN&md5=72f90125bb643d61ae339a256a2d69a1
109
Chien, C. T.; Li, S. S.; Lai, W. J.; Yeh, Y. C.; Chen, H. A.; Chen, I. S.; Chen, L. C.; Chen, K. H.; Nemoto, T.; Isoda, S. Tunable Photoluminescence from Graphene Oxide Angew. Chem., Int. Ed. 2012, 51, 6662– 6666 DOI: 10.1002/anie.201200474

Google Scholar

109
Tunable Photoluminescence from Graphene Oxide

Chien, Chih-Tao; Li, Shao-Sian; Lai, Wei-Jung; Yeh, Yun-Chieh; Chen, Hsin-An; Chen, I.-Shen; Chen, Li-Chyong; Chen, Kuei-Hsien; Nemoto, Takashi; Isoda, Seiji; Chen, Mingwei; Fujita, Takeshi; Eda, Goki; Yamaguchi, Hisato; Chhowalla, Manish; Chen, Chun-Wei

Angewandte Chemie, International Edition (2012), 51 (27), 6662-6666, S6662/1-S6662/10CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

Graphene oxide (GO) suspensions are prepd. that exhibit virtually all of the PL features obsd. by different groups, through careful and gradual redn. of the GO. The systematic evolution of the electronic structure and comprehensive anal. of steady-state and transient PL along with photoluminescence excitation (PLE) spectroscopy measurements indicate that two different types of electronically excited states are responsible for the obsd. emission characteristics.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XnsVGks7Y%253D&md5=c14a42d2edf4e74ef31c13c531636fa8
110
Zhang, X. F.; Shao, X.; Liu, S. Dual Fluorescence of Graphene Oxide: A Time-Resolved Study J. Phys. Chem. A 2012, 116, 7308– 7313 DOI: 10.1021/jp301755b

Google Scholar

110
Dual Fluorescence of Graphene Oxide: A Time-Resolved Study

Zhang, Xian-Fu; Shao, Xiaona; Liu, Suping

Journal of Physical Chemistry A (2012), 116 (27), 7308-7313CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)

The fluorescence properties of graphene oxide (GO) was studied by recording the fluorescence lifetime, fluorescence emission, and excitation spectra, as well as UV-visible and near-IR absorption spectra. For the first time, we showed that a blue band (ca. 440 nm) and a long wavelength (LW) band (ca. 700 nm) are coexistent, which can be recorded simultaneously by controlling concn., excitation wavelength, and pH values. Two bands are closely related by the protonation or deprotonation of GO. The blue band is favored by low GO concn., short excitation wavelength, and high pH value, while the LW band is favored by low pH and long excitation wavelength. To reveal the nature of the dual emission of GO, the fluorescence lifetimes under various conditions were also measured. The blue band contains three emitting components; one of them has a lifetime as long as 10 ns, and its emitting intensity is fairly sensitive to pH, showing the potential for applications in sensing H+ and fluorescence lifetime imaging. Combining the results under various conditions, we conclude that the electronic transition for this component is very likely due to n-π* transition. The LW band contains two main emitting components (0.2 and 2.1 ns) that also appear in the blue band as minor contributors; the related emission is assigned to π-π* transition. In summary, GO emission is of broadband (300-1250 nm), long-lived, pH sensitive, and excitation wavelength dependent. This makes it easily tailored for versatile applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XosVWitr4%253D&md5=d05cdbbf9dd74c16e0503243766cdcf2
111
Loh, K. P.; Bao, Q. L.; Eda, G.; Chhowalla, M. Graphene Oxide as a Chemically Tunable Platform for Optical Applications Nat. Chem. 2010, 2, 1015– 1024 DOI: 10.1038/nchem.907

Google Scholar

111
Graphene oxide as a chemically tunable platform for optical applications

Loh, Kian Ping; Bao, Qiaoliang; Eda, Goki; Chhowalla, Manish

Nature Chemistry (2010), 2 (12), 1015-1024CODEN: NCAHBB; ISSN:1755-4330. (Nature Publishing Group)

A review. Chem. derived graphene oxide (GO) is an atomically thin sheet of graphite that has traditionally served as a precursor for graphene, but is increasingly attracting chemists for its own characteristics. It is covalently decorated with O-contg. functional groups - either on the basal plane or at the edges - so that it contains a mixt. of sp2- and sp3-hybridized C atoms. Manipulation of the size, shape and relative fraction of the sp2-hybridized domains of GO by redn. chem. provides opportunities for tailoring its optoelectronic properties. For example, as-synthesized GO is insulating but controlled deoxidn. leads to an elec. and optically active material that is transparent and conducting. In contrast to pure graphene, GO is fluorescent over a broad range of wavelengths, owing to its heterogeneous electronic structure. The recent advances in optical properties of chem. derived GO, as well as new phys. and biol. applications are highlighted.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhsVOrsLzK&md5=6292b431a16bb3622b87145aa8db87ab
112
Iliut, M.; Gabudean, A. M.; Leordean, C.; Simon, T.; Teodorescu, C. M.; Astilean, S. Riboflavin Enhanced Fluorescence of Highly Reduced Graphene Oxide Chem. Phys. Lett. 2013, 586, 127– 131 DOI: 10.1016/j.cplett.2013.09.032

Google Scholar

There is no corresponding record for this reference.
113
Fernandez-Merino, M. J.; Paredes, J. I.; Villar-Rodil, S.; Guardia, L.; Solis-Fernandez, P.; Salinas-Torres, D.; Cazorla-Amoros, D.; Morallon, E.; Martinez-Alonso, A.; Tascon, J. M. D. Investigating the Influence of Surfactants on the Stabilization of Aqueous Reduced Graphene Oxide Dispersions and the Characteristics of Their Composite Films Carbon 2012, 50, 3184– 3194 DOI: 10.1016/j.carbon.2011.10.039

Google Scholar

There is no corresponding record for this reference.
114
Bourlinos, A. B.; Georgakilas, V.; Zboril, R.; Steriotis, T. A.; Stubos, A. K.; Trapalis, C. Aqueous-Phase Exfoliation of Graphite in the Presence of Polyvinylpyrrolidone for the Production of Water-Soluble Graphenes Solid State Commun. 2009, 149, 2172– 2176 DOI: 10.1016/j.ssc.2009.09.018

Google Scholar

114
Aqueous-phase exfoliation of graphite in the presence of polyvinylpyrrolidone for the production of water-soluble graphenes

Bourlinos, Athanasios B.; Georgakilas, Vasilios; Zboril, Radek; Steriotis, Theodore A.; Stubos, Athanasios K.; Trapalis, Christos

Solid State Communications (2009), 149 (47-48), 2172-2176CODEN: SSCOA4; ISSN:0038-1098. (Elsevier Ltd.)

Treatment of cryst. graphite fine powder with an aq. soln. of the harmless and versatile substance polyvinylpyrrolidone under sonication results in water-sol., polymer-protected graphene single layers without oxidn. or destruction of the sp2 character of the carbon core. The liq.-phase extn. of graphene monolayers was evidenced by TEM and AFM techniques, while their graphitic character was checked with Raman spectroscopy. Besides PVP, the water-sol. biopolymers albumin and sodic CM-cellulose were also employed successfully in the aq.-phase exfoliation of graphite, thereby supporting the generic character of the present method using a variety of suitable polymeric extractants.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtlagtbrF&md5=00ba4742b628f3496b7d01358722b42d
115
Liang, Y.; Wu, D.; Feng, X.; Mullen, K. Dispersion of Graphene Sheets in Organic Solvent Supported by Ionic Interactions Adv. Mater. 2009, 21, 1– 5 DOI: 10.1002/adma.200803160

Google Scholar

There is no corresponding record for this reference.
116
Carrasco, P. M.; Montes, S.; Garcia, I.; Borghei, M.; Jiang, H.; Odriozola, I.; Cabanero, G.; Ruiz, V. High-Concentration Aqueous Dispersions of Graphene Produced by Exfoliation of Graphite Using Cellulose Nanocrystals Carbon 2014, 70, 157– 163 DOI: 10.1016/j.carbon.2013.12.086

Google Scholar

116
High-concentration aqueous dispersions of graphene produced by exfoliation of graphite using cellulose nanocrystals

Carrasco, Pedro M.; Montes, Sarah; Garcia, Ignacio; Borghei, Maryam; Jiang, Hua; Odriozola, Ibon; Cabanero, German; Ruiz, Virginia

Carbon (2014), 70 (), 157-163CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

Stable high-concn. aq. dispersions (>1 mg ml-1) of single and few-layer graphene flakes were produced by direct exfoliation of graphite using cellulose nanocrystals (CNC). Biodegradable and widely available from renewable sources, CNC have proven to be very efficient graphene stabilizers even at low concns. (0.2 mg ml-1), thus enabling remarkably high graphene/CNC ratios (up to 3.8).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1Glt78%253D&md5=69a5203008d0f87cf8135439c1d27cab
117
Lotya, M.; King, P. J.; Khan, U.; De, S.; Coleman, J. N. High-Concentration, Surfactant-Stabilized Graphene Dispersions ACS Nano 2010, 4, 3155– 3162 DOI: 10.1021/nn1005304

Google Scholar

117
High-Concentration, Surfactant-Stabilized Graphene Dispersions

Lotya, Mustafa; King, Paul J.; Khan, Umar; De, Sukanta; Coleman, Jonathan N.

ACS Nano (2010), 4 (6), 3155-3162CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

A method is presented to produce graphene dispersions, stabilized in water by the surfactant sodium cholate, at concns. up to 0.3 mg/mL. The process uses low power sonication for long times (up to 400 h) followed by centrifugation to yield stable dispersions. The dispersed concn. increases with sonication time while the best quality dispersions are obtained for centrifugation rates between 500 and 2000 rpm. Detailed TEM anal. shows the flakes to consist of 1-10 stacked monolayers with up to 20% of flakes contg. just one layer. The av. flake consists of ∼4 stacked monolayers and has length and width of ∼1 μm and ∼400 nm, resp. These dimensions are surprisingly stable under prolonged sonication. However, the mean flake length falls from ∼1 μm to ∼500 nm as the centrifugation rate is increased from 500 to 5000 rpm. Raman spectroscopy shows the flake bodies to be relatively defect-free for centrifugation rates <2000 rpm. The dispersions can be easily cast into high-quality, free-standing films. The method extends the scope for scalable liq.-phase processing of graphene for a wide range of applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXlslyns7k%253D&md5=2e78a09fd09b3a97d5545653cbf5936b
118
Lotya, M.; Hernandez, Y.; King, P. J.; Smith, R. J.; Nicolosi, V.; Karlsson, L. S.; Blighe, F. M.; De, S.; Wang, Z.; McGovern, I. T. Liquid Phase Production of Graphene by Exfoliation of Graphite in Surfactant/Water Solutions J. Am. Chem. Soc. 2009, 131, 3611– 3620 DOI: 10.1021/ja807449u

Google Scholar

118
Liquid Phase Production of Graphene by Exfoliation of Graphite in Surfactant/Water Solutions

Lotya, Mustafa; Hernandez, Yenny; King, Paul J.; Smith, Ronan J.; Nicolosi, Valeria; Karlsson, Lisa S.; Blighe, Fiona M.; De, Sukanta; Wang, Zhiming; McGovern, I. T.; Duesberg, Georg S.; Coleman, Jonathan N.

Journal of the American Chemical Society (2009), 131 (10), 3611-3620CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

The authors demonstrated a method to disperse and exfoliate graphite to give graphene suspended in water-surfactant solns. Optical characterization of these suspensions allowed the partial optimization of the dispersion process. TEM showed the dispersed phase to consist of small graphitic flakes. More than 40% of these flakes had <5 layers with ∼3% of flakes consisting of monolayers. At. resoln. TEM shows the monolayers to be generally free of defects. The dispersed graphitic flakes are stabilized against reaggregation by Coulomb repulsion due to the adsorbed surfactant. The authors use DLVO and Hamaker theory to describe this stabilization. However, the larger flakes tend to sediment out over ∼6 wk, leaving only small flakes dispersed. It is possible to form thin films by vacuum filtration of these dispersions. Raman and IR spectroscopic anal. of these films suggests the flakes to be largely free of defects and oxides, although XPS shows evidence of a small oxide population. Individual graphene flakes can be deposited onto mica by spray coating, allowing statistical anal. of flake size and thickness. Vacuum filtered films are reasonably conductive and are semitransparent. Further improvements may result in the development of cheap transparent conductors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXit1ersrk%253D&md5=525945f5df60169f74d171b72894d9d3
119
Cai, M.; Thorpe, D.; Adamson, D. H.; Schniepp, H. C. Methods of Graphite Exfoliation J. Mater. Chem. 2012, 22, 24992– 25002 DOI: 10.1039/c2jm34517j

Google Scholar

119
Methods of graphite exfoliation

Cai, Minzhen; Thorpe, Daniel; Adamson, Douglas H.; Schniepp, Hannes C.

Journal of Materials Chemistry (2012), 22 (48), 24992-25002CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)

A review. For applications of two-dimensional graphene, com. viable sources are necessary. Exfoliation from bulk, stacked graphite is the most economical way to achieve large quantities of single layer graphene. A no. of methods have been developed to achieve exfoliation of graphite, each with advantages and disadvantages. In this review, we describe current exfoliation methods and techniques used to produce single layer materials from graphite precursors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs12ls7rK&md5=574d6181655b8628d94387327410a170
120
Yang, Q.; Pan, X.; Huang, F.; Li, K. Fabrication of High-Concentration and Stable Aqueous Suspensions of Graphene Nanosheets by Noncovalent Functionalization with Lignin and Cellulose Derivatives J. Phys. Chem. C 2010, 114, 3811– 3816 DOI: 10.1021/jp910232x

Google Scholar

120
Fabrication of High-Concentration and Stable Aqueous Suspensions of Graphene Nanosheets by Noncovalent Functionalization with Lignin and Cellulose Derivatives

Yang, Qiang; Pan, Xuejun; Huang, Fang; Li, Kecheng

Journal of Physical Chemistry C (2010), 114 (9), 3811-3816CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)

Stable aq. suspensions of graphene (G) nanosheets with high concn. (0.6-2 mg/mL) were prepd. through chem. redn. of exfoliated graphite oxide (EGO) with the aid of sodium lignosulfonate (SLS), sodium CM-cellulose (SCMC), and pyrene-contg. hydroxypropyl cellulose (HPC-Py). The noncovalently functionalized graphene nanosheets with a 3.3 ± 1.4 nm av. thickness were characterized using UV-visible spectroscopy, fluorescence spectroscopy, at. force microscopy, attenuated total reflectance micro-FTIR spectroscopy, and Raman spectroscopy.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhvFWgu70%253D&md5=025c22accd51fe719a9c7a8b1da09fe1
121
Choi, E. Y.; Han, T. H.; Hong, J.; Kim, J. E.; Lee, S. H.; Kim, H. W.; Kim, S. O. Noncovalent Functionalization of Graphene with End-Functional Polymers J. Mater. Chem. 2010, 20, 1907– 1912 DOI: 10.1039/b919074k

Google Scholar

121
Noncovalent functionalization of graphene with end-functional polymers

Choi, Eun-Young; Han, Tae Hee; Hong, Jihyun; Kim, Ji Eun; Lee, Sun Hwa; Kim, Hyun Wook; Kim, Sang Ouk

Journal of Materials Chemistry (2010), 20 (10), 1907-1912CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)

Stable dispersion of reduced graphene in various org. solvents was achieved via noncovalent functionalization with amine-terminated polymers. An aq. dispersion of reduced graphene was prepd. by chem. redn. of graphene oxide in aq. media and was vacuum filtered to generate reduced graphene sheets. Good solvents and nonsolvents for the dried reduced graphene were evaluated using a soly. test. To achieve stable dispersion in the evaluated nonsolvents, amine-terminated polystyrene was noncovalently functionalized to the graphene, while graphene sheets were phase transferred via sonication from aq. phase to the org. nonsolvent phase, including the amine-terminated polymers. Thorough FTIR and Raman spectroscopy study verified that the protonated amine terminal group of polystyrene underwent noncovalent functionalization to the carboxylate groups at the graphene surface, providing the high dispersibility in various org. media.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXitleitrc%253D&md5=4a7ecfe16241f5895c69e628c875e6d5
122
Lian, M.; Fan, J.; Shi, Z.; Li, H.; Yin, J. Kevlar-Functionalized Graphene Nanoribbon for Polymer Reinforcement Polymer 2014, 55, 2578– 2587 DOI: 10.1016/j.polymer.2014.03.059

Google Scholar

122
Kevlar-functionalized graphene nanoribbon for polymer reinforcement

Lian, Min; Fan, Jinchen; Shi, Zixing; Li, Hong; Yin, Jie

Polymer (2014), 55 (10), 2578-2587CODEN: POLMAG; ISSN:0032-3861. (Elsevier Ltd.)

Multiwalled carbon nanotubes (MWCNTs) have been widely used as reinforcement fillers in past decades. However, the reinforcement effect has been greatly hindered by the limited available interface area (AIA) with polymer matrixes for polymer composites. Successively, the method of oxidative unzipping MWCNTs into graphene nanoribbons (GNRs) was demonstrated to be the effective way for addressing the inherent drawback of MWCNTs. However, the GNRs are easy to agglomerate in polymer matrix even at relatively low loading amt. In this paper, we found that the functionalization of GNRs with Kevlar can significantly improve the dispersion state of GNRs in polymer matrix. Consequently, Kevlar-functionalized graphene nanoribbons (KGNRs) were successfully prepd. through non-covalent functionalization of π-π stacking interaction between the arom. area of Kevlar and the graphitic surface of GNRs. As-prepd. KGNRs were characterized by FT-IR, TGA, XRD and TEM measurements. Poly(vinyl chloride) (PVC) and poly(Me methacrylate) (PMMA) were selected as model polymers to investigate the reinforcement effect of KGNRs. The KGNRs could be well dispersed in PVC and PMMA matrixes at relatively high loading level. Meantime, the ultimate tensile strengths and Young's modulus of KGNRs/PVC and KGNRs/PMMA composite films were significantly improved. Based on the observations above, KGNRs hold great promise in many potential applications in the future.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXmsVWgsb4%253D&md5=76f581e8db98af69491a17fd5bf23092
123
Zhang, J.; Xu, Y.; Cui, L.; Fu, A.; Yang, W.; Barrow, C.; Liu, J. Mechanical Properties of Graphene Films Enhanced by Homo-Telechelic Functionalized Polymer Fillers via p–p Stacking Interactions Composites, Part A 2015, 71, 1– 8 DOI: 10.1016/j.compositesa.2014.12.013

Google Scholar

123
Mechanical properties of graphene films enhanced by homo-telechelic functionalized polymer fillers via π-π stacking interactions

Zhang, Jizhen; Xu, Yuanhong; Cui, Liang; Fu, Aiping; Yang, Wenrong; Barrow, Colin; Liu, Jingquan

Composites, Part A: Applied Science and Manufacturing (2015), 71 (), 1-8CODEN: CASMFJ; ISSN:1359-835X. (Elsevier Ltd.)

Most researches on graphene/polymer composites are focusing on improving the mech. and elec. properties of polymers at low graphene content instead of paying attention to constructing graphene's macroscopic structures. In current study, the homo-telechelic functionalized polyethylene glycols (FPEGs) were tailored with π-orbital-rich groups (namely Ph, pyrene and di-pyrene) via esterification reactions, which enhanced the interaction between polyethylene glycol (PEG) mols. and chem. reduced graphene oxide (RGO) sheets. The π-π stacking interactions between graphene sheets and π-orbital-rich groups endowed the composite films with enhanced tensile strength and tunable elec. cond. The formation of graphene network structure mediated by the FPEGs fillers via π-π stacking non-covalent interactions should account for the exptl. results. The exptl. investigations were also complemented with theor. calcn. using a d. functional theory. Atomic force microscope, scanning electron microscope, X-ray diffraction, NMR, thermal gravimetric anal., UV-vis and fluorescence spectroscopy were used to monitor the step-wise prepn. of graphene composite films.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXovFyksA%253D%253D&md5=76663e335e198a689ed018d0cda286bb
124
Chandra, V.; Kim, K. S. Highly Selective Adsorption of Hg²⁺ by Polypyrrole-Reduced Graphene Oxide Composite Chem. Commun. 2011, 47, 3942– 3944 DOI: 10.1039/c1cc00005e

Google Scholar

There is no corresponding record for this reference.
125
Stankovich, S.; Piner, R. D.; Chen, X.; Wu, N.; Nguyen, S. T.; Ruoff, R. S. Stable Aqueous Dispersions of Graphitic Nanoplatelets via the Reduction of Exfoliated Graphite Oxide in the Presence of Poly(sodium 4-styrenesulfonate) J. Mater. Chem. 2006, 16, 155– 158 DOI: 10.1039/B512799H

Google Scholar

125
Stable aqueous dispersions of graphitic nanoplatelets via the reduction of exfoliated graphite oxide in the presence of poly(sodium 4-styrenesulfonate)

Stankovich, Sasha; Piner, Richard D.; Chen, Xinqi; Wu, Nianqiang; Nguyen, SonBinh T.; Ruoff, Rodney S.

Journal of Materials Chemistry (2006), 16 (2), 155-158CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)

For the first time, stable aq. dispersions of polymer-coated graphitic nanoplatelets can be prepd. via an exfoliation/in-situ redn. of graphite oxide in the presence of poly(sodium 4-styrenesulfonate).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtlanurzO&md5=f466af7e066bcec151c0575b69cfeaae
126
Bai, H.; Xu, Y.; Zhao, L.; Li, C.; Shi, G. Non-Covalent Functionalization of Graphene Sheets by Sulfonated Polyaniline Chem. Commun. 2009, 1667– 1669 DOI: 10.1039/b821805f

Google Scholar

126
Non-covalent functionalization of graphene sheets by sulfonated polyaniline

Bai, Hua; Xu, Yuxi; Zhao, Lu; Li, Chun; Shi, Gaoquan

Chemical Communications (Cambridge, United Kingdom) (2009), (13), 1667-1669CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)

A review. Graphene sheets were stably dispersed in water by functionalization with sulfonated polyaniline (SPANI), and the composite film of SPANI-functionalized graphene showed improved electrochem. stability and enhanced electrocatalytic activity.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXjt1ant7g%253D&md5=225d266c0b9370f5a47ab02eeadc93fd
127
Matos, C. F.; Galembeck, F.; Zarbin, A. J. G. Multifunctional and Environmentally Friendly Nanocomposites between Natural Rubber and Graphene or Graphene Oxide Carbon 2014, 78, 469– 479 DOI: 10.1016/j.carbon.2014.07.028

Google Scholar

127
Multifunctional and environmentally friendly nanocomposites between natural rubber and graphene or graphene oxide

Matos, Carolina F.; Galembeck, Fernando; Zarbin, Aldo J. G.

Carbon (2014), 78 (), 469-479CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

This work describes a green route to multifunctional nanocomposite materials composed of natural rubber (NR) latex and graphene (rGO) or graphene oxide (GO). Aq. solns. with different concns. of GO and rGO (prepd. with the surfactant cetyltrimethylammonium bromide - CTAB) were mixed with natural rubber latex under magnetic stirring followed by sonication. The slurries obtained after casting were dried in an oven in air at 70 °C for 24 h. The nanocomposites were characterized by TEM and SEM, AFM and KFM. The thermal, elec. and mech. properties were evaluated using TGA, resistivity measurements (four-point) and DMA. Swelling tests were performed using three solvents with different polarities: xylene, isopropanol and water. The inclusion of filler networks in the polymeric matrixes provided significant improvements in the elec., chem. and mech. properties, in comparison to the unfilled polymer. In addn., the nanocomposites proved to be biodegradable.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1entrzE&md5=3870ef725dbf0e4b97b8d330aec6a2d8
128
Hsiao, S. T.; Ma, C. C. M.; Tien, H. W.; Liao, W. H.; Wang, Y. S.; Li, S. M.; Huang, Y. C. Using a Non-Covalent Modification to Prepare a High Electromagnetic Interference Shielding Performance Graphene Nanosheet/Water-Borne Polyurethane Composite Carbon 2013, 60, 57– 66 DOI: 10.1016/j.carbon.2013.03.056

Google Scholar

128
Using a non-covalent modification to prepare a high electromagnetic interference shielding performance graphene nanosheet/water-borne polyurethane composite

Hsiao, Sheng-Tsung; Ma, Chen-Chi M.; Tien, Hsi-Wen; Liao, Wei-Hao; Wang, Yu-Sheng; Li, Shin-Ming; Huang, Yu-Chin

Carbon (2013), 60 (), 57-66CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

The authors prepd. flexible, lightwt., and high electromagnetic interference (EMI) shielding performance graphene nanosheet (GNS)/water-borne polyurethane (WPU) composites. WPU, with sulfonate functional groups, was used as the polymer matrix. By adsorbing the cationic surfactant (stearyl tri-Me ammonium chloride) on the surface of the GNSs (S-GNSs), restacking and aggregation of the GNSs were efficiently suppressed, which also attracted sulfonate groups from the WPU matrix. Because of the favorable interfacial interactions arising from electrostatic attraction, the S-GNS exhibited good compatibility with the WPU matrix. Such a homogeneous dispersion contributed to the construction of an elec. conductive network. The S-GNS/WPU composite exhibited a low elec. cond. percolation threshold and an outstanding enhanced elec. cond. of ∼5.1 S/m. A high EMI shielding effectiveness of ∼32 dB was obtained by the WPU composites with contents of 5 vol.% (∼7.7%) S-GNSs.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXms1yrtbY%253D&md5=e95ed4ca51031d6e37228551153cc19a
129
Lee, D. Y.; Khatun, Z.; Lee, J. H.; Lee, Y.; In, I. Blood Compatible Graphene/Heparin Conjugate through Noncovalent Chemistry Biomacromolecules 2011, 12, 336– 341 DOI: 10.1021/bm101031a

Google Scholar

129
Blood Compatible Graphene/Heparin Conjugate through Noncovalent Chemistry

Lee, Da Young; Khatun, Zehedina; Lee, Ji-Hoon; Lee, Yong-kyu; In, Insik

Biomacromolecules (2011), 12 (2), 336-341CODEN: BOMAF6; ISSN:1525-7797. (American Chemical Society)

Blood compatible graphene/heparin conjugate is simply formulated through noncovalent interaction between chem. reduced graphene and heparin. Charge repulsion of neg. charged heparin on graphene plates renders hydrophobic graphene to be solubilized in aq. media without any pptn. or aggregation even after 6 mo. Unfractioned heparin (UFH) with higher mol. wt. was effective for graphene solubilization while low mol. wt. heparin (LMWH) was not. Noncovalently interacting heparin chains on graphene plates preserve their anticoagulant activity after conjugation with graphene. Graphene/UFH conjugate shows much enhanced anti-factor Xa (FXa) activity of 29.6 IU/mL compared with pristine graphene oxide (GO; 1.03 IU/mL).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXivFCgsg%253D%253D&md5=ae867232818507bdef95a8d8acd2454f
130
Zhang, Y.; Zhang, J.; Huang, X.; Zhou, X.; Wu, H.; Guo, S. Assembly of Graphene Oxide–Enzyme Conjugates through Hydrophobic Interaction Small 2012, 8, 154– 159 DOI: 10.1002/smll.201101695

Google Scholar

There is no corresponding record for this reference.
131
Zhang, J.; Zhang, F.; Yang, H.; Huang, X.; Liu, H.; Zhang, J.; Guo, S. Graphene Oxide as a Matrix for Enzyme Immobilization Langmuir 2010, 26, 6083– 6085 DOI: 10.1021/la904014z

Google Scholar

131
Graphene Oxide as a Matrix for Enzyme Immobilization

Zhang, Jiali; Zhang, Feng; Yang, Haijun; Huang, Xuelei; Liu, Hui; Zhang, Jingyan; Guo, Shouwu

Langmuir (2010), 26 (9), 6083-6085CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)

Graphene oxide (GO), having a large sp. surface area and abundant functional groups, provides an ideal substrate for study enzyme immobilization. We demonstrated that the enzyme immobilization on the GO sheets could take place readily without using any crosslinking reagents and addnl. surface modification. The atomically flat surface enabled us to observe the immobilized enzyme in the native state directly using at. force microscopy (AFM). Combining the AFM imaging results of the immobilized enzyme mols. and their catalytic activity, we illustrated that the conformation of the immobilized enzyme is mainly detd. by interactions of enzyme mols. with the functional groups of GO.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXjsFOmtLg%253D&md5=f93bfbcbfbed2d52c0b582aba257157c
132
Alwarappan, S.; Boyapalle, S.; Kumar, A.; Li, C. Z.; Mohapatra, S. Comparative Study of Single-, Few-, and Multilayered Graphene toward Enzyme Conjugation and Electrochemical Response J. Phys. Chem. C 2012, 116, 6556– 6559 DOI: 10.1021/jp211201b

Google Scholar

132
Comparative Study of Single-, Few-, and Multilayered Graphene toward Enzyme Conjugation and Electrochemical Response

Alwarappan, Subbiah; Boyapalle, Sandhya; Kumar, Ashok; Li, Chen-Zhong; Mohapatra, Shyam

Journal of Physical Chemistry C (2012), 116 (11), 6556-6559CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)

Graphene, with its exceptional mech., thermal, elec., optical, and electronic properties may exist as single-, few-, or multilayered thin sheets. Though the no. of layers may affect cond., its role toward enzyme immobilization and enzymic biosensing applications is unknown. Herein, the authors report the electrochem. performance of electrodes of graphene comprising varying layers immobilized with the enzyme glucose oxidase for the detection of the model analyte glucose. It is interesting to note that these different-layered graphene exhibit an identical electrochem. performance and sensitivity toward the detection of glucose. In addn., all of these electrodes exhibited a similar percentage of electrode fouling after 60 cycles. Following this, the authors have then calcd. the amt. of enzyme bound to the electrode surface. Results indicated that single-, few-, and multilayered graphene electrodes immobilize a similar amt. of glucose oxidase. Thus, together, these results demonstrate that the no. of layers stacked within the graphene structure have no significant role in the enzyme conjugation and subsequent electrochem. response during the electroanal.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XislSku70%253D&md5=e7daeecd7ead279482ed370499d81d31
133
Heien, M. L. A. V.; Khan, A. S.; Ariansen, J. L.; Cheer, J. F.; Phillips, P. E. M.; Wassum, K. M.; Wightman, R. M. Proc. Natl. Acad. Sci. U. S. A. 2005, 102, 10023– 10028 DOI: 10.1073/pnas.0504657102

Google Scholar

There is no corresponding record for this reference.
134
Wang, Y.; Li, Y.; Tang, L.; Lu, J.; Li, J. Application of Graphene-Modified Electrode for Selective Detection of Dopamine Electrochem. Commun. 2009, 11, 889– 892 DOI: 10.1016/j.elecom.2009.02.013

Google Scholar

134
Application of graphene-modified electrode for selective detection of dopamine

Wang, Ying; Li, Yueming; Tang, Longhua; Lu, Jin; Li, Jinghong

Electrochemistry Communications (2009), 11 (4), 889-892CODEN: ECCMF9; ISSN:1388-2481. (Elsevier B.V.)

Graphene was prepd. chem. by Hummers and Offeman method and the graphene-modified electrode was applied in selective detn. of dopamine with a linear range from 5 μM to 200 μM in a large excess of ascorbic acid. Selective detection was realized in completely eliminating ascorbic acid, different from the methods based on the potential sepns. π-π stacking interaction between dopamine and graphene surface may accelerate the electron transfer whereas weaken the ascorbic acid oxidn. on this graphene-modified electrode. The resulting graphene-modified electrode also showed a better performance than multi-walled carbon nanotubes-modified electrode. The phenomena were considered from the elusive 2D structure and unique electronic properties of graphene.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXjslOjt7w%253D&md5=264faf18d4e83345ac277ca694b34420
135
Kim, Y. R.; Bong, S.; Kang, Y. J.; Yang, Y.; Mahajan, R. K.; Kim, J. S.; Kim, H. Electrochemical Detection of Dopamine in the Presence of Ascorbic Acid Using Graphene Modified Electrodes Biosens. Bioelectron. 2010, 25, 2366– 2369 DOI: 10.1016/j.bios.2010.02.031

Google Scholar

135
Electrochemical detection of dopamine in the presence of ascorbic acid using graphene modified electrodes

Kim, Yang-Rae; Bong, Sungyool; Kang, Yeon-Joo; Yang, Yongtak; Mahajan, Rakesh Kumar; Kim, Jong Seung; Kim, Hasuck

Biosensors & Bioelectronics (2010), 25 (10), 2366-2369CODEN: BBIOE4; ISSN:0956-5663. (Elsevier B.V.)

Dopamine plays a significant role in the function of human metab. It is important to develop sensitive sensor for the detn. of dopamine without the interference by ascorbic acid. This paper reports the synthesis of graphene using a modified Hummer's method and its application for the electrochem. detection of dopamine. Electrochem. measurements were performed at glassy carbon electrode modified with graphene via drop-casting method. Cyclic voltammogram of ferri/ferrocyanide redox couple at graphene modified electrode showed an increased current intensity compared with glassy carbon electrode and graphite modified electrode. The decrease of charge transfer resistance was also analyzed by electrochem. impedance spectroscopy. The capacity of graphene modified electrode for selective detection of dopamine was confirmed in a sufficient amt. of ascorbic acid (1 mM). The obsd. linear range for the detn. of dopamine concn. was from 4 μM to 100 μM. The detection limit was estd. to be 2.64 μM.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXlvVegsLs%253D&md5=8acab5590c9a2aa383c1ed9c81f1078d
136
Lian, Q.; He, Z.; He, Q.; Luo, A.; Yan, K.; Zhang, D.; Lu, X.; Zhou, X. Simultaneous Determination of Ascorbic Acid, Dopamine and Uric Acid Based on Tryptophan Functionalized Graphene Anal. Chim. Acta 2014, 823, 32– 39 DOI: 10.1016/j.aca.2014.03.032

Google Scholar

136
Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene

Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia; Lu, Xiaoquan; Zhou, Xibin

Analytica Chimica Acta (2014), 823 (), 32-39CODEN: ACACAM; ISSN:0003-2670. (Elsevier B.V.)

A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π-π conjugate action between graphene (GR) and tryptophan (Trp) mol. The material as prepd. had well dispersivity in water and better cond. than pure GR. The surface morphol. of Trp-GR was characterized by SEM (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochem. behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The sepn. of the oxidn. peak potentials for AA-DA, DA-UA and UA-AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously detg. AA, DA, and UA. Differential pulse voltammetry (DPV) was used for the detn. of AA, DA, and UA in their mixt. Under optimum conditions, the linear response ranges for the detn. of AA, DA, and UA were 0.2-12.9 mM, 0.5-110 μM, and 10-1000 μM, with the detection limits (S/N = 3) of 10.09 μM, 0.29 μM and 1.24 μM, resp. Furthermore, the modified electrode was investigated for real sample anal.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXls1ajs7g%253D&md5=e85ea000729d4f168858940f94931c78
137
Zhang, W.; Chai, Y.; Yuan, R.; Chen, S.; Han, J.; Yuan, D. Facile Synthesis of Graphene Hybrid Tube-Like Structure for Simultaneous Detection of Ascorbic Acid, Dopamine, Uric Acid and Tryptophan Anal. Chim. Acta 2012, 756, 7– 12 DOI: 10.1016/j.aca.2012.10.044

Google Scholar

There is no corresponding record for this reference.
138
Lv, M.; Mei, T.; Zhang, C.; Wang, X. Selective and Sensitive Electrochemical Detection of Dopamine Based on Water-Soluble Porphyrin Functionalized Graphene Nanocomposites RSC Adv. 2014, 4, 9261– 9270 DOI: 10.1039/c3ra47234e

Google Scholar

138
Selective and sensitive electrochemical detection of dopamine based on water-soluble porphyrin functionalized graphene nanocomposites

Lv, Meijiao; Mei, Tao; Zhang, Chang'an; Wang, Xianbao

RSC Advances (2014), 4 (18), 9261-9270CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

A biosensor, based on a water-sol. porphyrin-reduced graphene oxide (RGO) nanocomposite synthesized by simultaneous covalent and non-covalent strategies through arom. π-π stacking and the formation of chem. bonds, was prepd. for selective and sensitive detection of dopamine (DA). Compared with graphene or porphyrin alone, porphyrin-RGO nanocomposites exhibited unique advantages for the detection of DA in the presence of interfering substances such as uric acid (UA) and ascorbic acid (AA). The cyclic voltammetry (CV) curves indicated that the porphyrin-RGO modified glassy carbon electrode (GCE) had larger active area and better electrochem. catalytic activity which could attribute to the π-π stacking and the electrostatic attraction between pos. charged DA and neg. charged porphyrin-RGO, which can accelerate the electron transfer and weaken the oxidn. of AA/UA on the porphyrin-RGO/GCE. Differential pulse voltammetry (DPV) was used for the quant. detection of DA. The peak currents increased linearly with the increasing concn. of DA in the range of 1 × 10-6 to 7 × 10-5 M, and the limit of detection (LOD) (S/N = 3) was estd. to be 9.45 × 10-9 M. More importantly, the biosensor exhibited good stability and reproducibility, and would provide a superior platform in the biol. anal.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1yjs7s%253D&md5=966b92b539a79a90c23ff365be7bc5b5
139
Zhang, Y.; Xia, Z.; Liu, H.; Yang, M.; Lin, L.; Li, Q. Hemin Graphene Oxide-Pristine Carbon Nanotubes Complexes with Intrinsic Peroxidase-Like Activity for the Detection of H₂O₂ and Simultaneous Determination for Trp, AA, DA, and UA Sens. Actuators, B 2013, 188, 496– 501 DOI: 10.1016/j.snb.2013.07.010

Google Scholar

139
Hemin-graphene oxide-pristine carbon nanotubes complexes with intrinsic peroxidase-like activity for the detection of H2O2 and simultaneous determination for Trp, AA, DA, and UA

Zhang, Yu; Xia, Zhi; Liu, Hong; Yang, Mingjian; Lin, Longli; Li, Qianzhu

Sensors and Actuators, B: Chemical (2013), 188 (), 496-501CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)

This paper demonstrated a simple wet-chem. strategy for synthesizing hemin-graphene oxide-pristine carbon nanotubes complexes (H-GO-CNTs) through the π-π interactions, and it was used to construct a novel dual sensor for the detn. of H2O2 and the simultaneous detn. of ascorbic acid (AA), dopamine (DA), uric acid (UA), and tryptophan (Trp). This sensor possesses the advantages of both hemin and GO-CNTs and exhibits several interesting properties. First, hemin has excellent catalysis and intrinsic peroxidase-like activity that can facilitate the catalytic redn. of H2O2. Second, GO can absorb the CNTs through the π-stacking interaction, thus causing pristine CNTs to stably disperse in aq. media. Third, one-dimensional CNTs (1D) combined with 2D GO to form a 3D nanohybrid. This porous structure on the surface of the electrode can facilitate the discrimination of many species which oxidize or reduce at similar potentials. Cyclic voltammetry (CV), SEM (SEM), transmission electron microscopy (TEM) and different pulse voltammetry (DPV) were employed to characterize the sensor. It exhibits good anal. performance, acceptable stability and good selectivity.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs1Sgt7jL&md5=4b1588ab00e12dbb6f094dac9f32c6eb
140
Pandikumar, A.; Thien Soon How, G.; See, T. P.; Omar, F. S.; Jayabal, S.; Zangeneh Kamali, K.; Yusoff, N.; Jamil, A.; Ramaraj, R.; Abraham John, S. Graphene and Its Nanocomposite Material Based Electrochemical Sensor Platform for Dopamine RSC Adv. 2014, 4, 63296– 63323 DOI: 10.1039/C4RA13777A

Google Scholar

140
Graphene and its nanocomposite material based electrochemical sensor platform for dopamine

Pandikumar, Alagarsamy; Soon How, Gregory Thien; See, Teo Peik; Omar, Fatin Saiha; Jayabal, Subramaniam; Kamali, Khosro Zangeneh; Yusoff, Norazriena; Jamil, Asilah; Ramaraj, Ramasamy; John, Swamidoss Abraham; Lim, Hong Ngee; Huang, Nay Ming

RSC Advances (2014), 4 (108), 63296-63323CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

A review. Dopamine (DA) is an important catecholamine neurotransmitter in the mammalian central nervous system that influences several physiol. functions. The impact of DA levels within the human body significantly affects the body functions. Maintaining DA level is essential and the electrochem. detection methods are often used to detect the DA level to regulate the body function. In this review, graphene (functionalized graphene and N-doped graphene) and its composites (metal, metal oxide, polymer, carbonaceous materials, clay, zeolite, and metal-org. framework based graphene composites) modified electrodes with their improved sensing performance towards DA along with several interfering species are described. Further, recent developments on the fabrication of various graphene based composite modified electrodes are also presented. Some important strategies to improve the selectivity and sensitivity towards DA with graphene based composite modified electrodes are also described.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvV2gtb%252FE&md5=a091dd571052f26a6534e810cf542f51
141
Min, S. K.; Kim, W. Y.; Cho, Y.; Kim, K. S. Fast DNA Sequencing with a Graphene-Based Nanochannel Device Nat. Nanotechnol. 2011, 6, 162– 165 DOI: 10.1038/nnano.2010.283

Google Scholar

141
Fast DNA sequencing with a graphene-based nanochannel device

Min, Seung Kyu; Kim, Woo Youn; Cho, Yeonchoo; Kim, Kwang S.

Nature Nanotechnology (2011), 6 (3), 162-165CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)

Devices in which a single strand of DNA is threaded through a nanopore could be used to efficiently sequence DNA. However, various issues will have to be resolved to make this approach practical, including controlling the DNA translocation rate, suppressing stochastic nucleobase motions, and resolving the signal overlap between different nucleobases. Here, we demonstrate theor. the feasibility of DNA sequencing using a fluidic nanochannel functionalized with a graphene nanoribbon. This approach involves deciphering the changes that occur in the conductance of the nanoribbon as a result of its interactions with the nucleobases via π-π stacking. We show that as a DNA strand passes through the nanochannel, the distinct conductance characteristics of the nanoribbon (calcd. using a method based on d. functional theory coupled to non-equil. Green function theory18-20) allow the different nucleobases to be distinguished using a data-mining technique and a two-dimensional transient autocorrelation anal. This fast and reliable DNA sequencing device should be exptl. feasible in the near future.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXislCjsrw%253D&md5=7db4daac71c95292aa972cd29b6e6c8d
142
Zhu, C.; Du, D.; Lin, Y. Graphene and Graphene-Like 2D Materials for Optical Biosensing and Bioimaging: A Review 2D Mater. 2015, 2, 032004 DOI: 10.1088/2053-1583/2/3/032004

Google Scholar

142
Graphene and graphene-like 2D materials for optical biosensing and bioimaging: a review

Zhu, Chengzhou; Du, Dan; Lin, Yuehe

2D Materials (2015), 2 (3), 032004/1-032004/17CODEN: DMATB7; ISSN:2053-1583. (IOP Publishing Ltd.)

The increasing demands of bioassay and biomedical applications have significantly promoted the rational design and fabrication of a wide range of functional nanomaterials. Coupling these advanced nanomaterials with biomol. recognition events leads to novel sensing and diagnostic platforms. Because of their unique structures and multifunctionalities, two-dimensional nanomaterials, such as graphene and graphene-like materials (e.g., graphitic carbon nitride, transition metal dichalcogenides, boron nitride, and transition metal oxides), have stimulated great interest in the field of optical biosensors and imaging because of their innovative mech., physicochem. and optical properties. Depending on the different applications, the graphene and graphene-like nanomaterials can be tailored to form either fluorescent emitters or efficient fluorescence quenchers, making them powerful platforms for fabricating a series of optical biosensors to sensitively detect various targets including ions, small biomols.,DNA/RNAand proteins. This review highlights the recent progress in optical biosensors based on graphene and graphene-like 2D materials and their imaging applications. Finally, the opportunities and some crit. challenges in this field are also addressed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXkslWkur4%253D&md5=e4fe32a7675e66a20d7ca806be903895
143
Liu, Y.; Dong, X.; Chen, P. Biological and Chemical Sensors Based on Graphene Materials Chem. Soc. Rev. 2012, 41, 2283– 2307 DOI: 10.1039/C1CS15270J

Google Scholar

143
Biological and chemical sensors based on graphene materials

Liu, Yuxin; Dong, Xiaochen; Chen, Peng

Chemical Society Reviews (2012), 41 (6), 2283-2307CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)

A review. Owing to their extraordinary elec., chem., optical, mech. and structural properties, graphene and its derivs. have stimulated exploding interests in their sensor applications ever since the 1st isolation of free-standing graphene sheets in year 2004. This article critically and comprehensively reviews the emerging graphene-based electrochem. sensors, electronic sensors, optical sensors, and nanopore sensors for biol. or chem. detection. The authors emphasize on the underlying detection (or signal transduction) mechanisms, the unique roles and advantages of the used graphene materials. Properties and prepns. of different graphene materials, their functionalizations are also comparatively discussed in view of sensor development. Finally, the perspective and current challenges of graphene sensors are outlined (312 refs.).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XivFWlsLo%253D&md5=5454d4561e7ab73b83c94265bc2b3d70
144
Green, N. S.; Norton, M. L. Interactions of DNA with graphene and sensing applications of graphene field-effect transistor devices: A review Anal. Chim. Acta 2015, 853, 127– 142 DOI: 10.1016/j.aca.2014.10.023

Google Scholar

144
Interactions of DNA with graphene and sensing applications of graphene field-effect transistor devices: A review

Green, Nathaniel S.; Norton, Michael L.

Analytica Chimica Acta (2015), 853 (), 127-142CODEN: ACACAM; ISSN:0003-2670. (Elsevier B.V.)

A review. Graphene field-effect transistors (GFET) have emerged as powerful detection platforms enabled by the advent of chem. vapor deposition (CVD) prodn. of the unique atomically thin 2D material on a large scale. DNA aptamers, short target-specific oligonucleotides, are excellent sensor moieties for GFETs due to their strong affinity to graphene, relatively short chain-length, selectivity, and a high degree of analyte variability. However, the interaction between DNA and graphene is not fully understood, leading to questions about the structure of surface-bound DNA, including the morphol. of DNA nanostructures and the nature of the electronic response seen from analyte binding. This review critically evaluates recent insights into the nature of the DNA graphene interaction and its affect on sensor viability for DNA, small mols., and proteins with respect to previously established sensing methods. We first discuss the sorption of DNA to graphene to introduce the interactions and forces acting in DNA based GFET devices and how these forces can potentially affect the performance of increasingly popular DNA aptamers and even future DNA nanostructures as sensor substrates. Next, we discuss the novel use of GFETs to detect DNA and the underlying electronic phenomena that are typically used as benchmarks for characterizing the analyte response of these devices. Finally, we address the use of DNA aptamers to increase the selectivity of GFET sensors for small mols. and proteins and compare them with other, state of the art, detection methods.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslOrtbbI&md5=a25aa3f596797cc4de596e54f6cc3c3c
145
Lu, C. H.; Yang, H. H.; Zhu, C. L.; Chen, X.; Chen, G. N. A Graphene Platform for Sensing Biomolecules Angew. Chem., Int. Ed. 2009, 48, 4785– 4787 DOI: 10.1002/anie.200901479

Google Scholar

145
A Graphene Platform for Sensing Biomolecules

Lu, Chun-Hua; Yang, Huang-Hao; Zhu, Chun-Ling; Chen, Xi; Chen, Guo-Nan

Angewandte Chemie, International Edition (2009), 48 (26), 4785-4787CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

The use of graphene oxide (GO) as a platform for the sensitive and selective detection of DNA and proteins is presented. The interaction of GO and dye-labeled single-stranded DNA leads to quenching of the dye fluorescence. Conversely, the presence of a target DNA or protein leads to the binding of the dye-labeled DNA and target, releasing the DNA from GO, thereby restoring the dye fluorescence.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXntlOitb4%253D&md5=60952d44796a7b63706a2225a19f4729
146
Bonanni, A.; Pumera, M. Graphene Platform for Hairpin-DNA Based Impedimetric Genosensing ACS Nano 2011, 5, 2356– 2361 DOI: 10.1021/nn200091p

Google Scholar

There is no corresponding record for this reference.
147
Loo, A. H.; Bonanni, A.; Pumera, M. An Insight into the Hybridization Mechanism of Hairpin DNA Physically Immobilized on Chemically Modified Graphenes Analyst 2013, 138, 467– 471 DOI: 10.1039/C2AN36199J

Google Scholar

There is no corresponding record for this reference.
148
Giovanni, M.; Bonanni, A.; Pumera, M. Detection of DNA Hybridization on Chemically Modified Graphene Platforms Analyst 2012, 137, 580– 583 DOI: 10.1039/C1AN15910K

Google Scholar

There is no corresponding record for this reference.
149
Loo, A. H.; Bonanni, A.; Ambrosi, A.; Poh, H. L.; Pumera, M. Impedimetric Immunoglobulin G Immunosensor Based on Chemically Modified Graphenes Nanoscale 2012, 4, 921– 925 DOI: 10.1039/C2NR11492E

Google Scholar

149
Impedimetric immunoglobulin G immunosensor based on chemically modified graphenes

Loo, Adeline Huiling; Bonanni, Alessandra; Ambrosi, Adriano; Poh, Hwee Ling; Pumera, Martin

Nanoscale (2012), 4 (3), 921-925CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

Immunosensors which display high sensitivity and selectivity are of utmost importance to the biomedical field. Graphene is a material which has immense potential for the fabrication of immunosensors. For the first time, we evaluate the immunosensing capabilities of various graphene surfaces in this work. We propose a simple and label-free electrochem. impedimetric immunosensor for IgG (IgG) based on chem. modified graphene (CMG) surfaces such as graphite oxide, graphene oxide, thermally reduced graphene oxide and electrochem. reduced graphene oxide. Disposable electrochem. printed electrodes were first modified with CMG materials before anti-IgG (anti-IgG), which is specific to IgG, was immobilized. The principle of detection lies in the changes in impedance spectra of the redox probe after the attachment of IgG to the immobilized anti-IgG. It was found that thermally reduced graphene oxide has the best performance when compared to the other CMG materials. In addn., the optimal concn. of anti-IgG to be deposited onto the modified electrode surface is 10 μg ml-1 and the linear range of detection of the immunosensor is from 0.3 μg ml-1 to 7 μg ml-1. Finally, the fabricated immunosensor also displays selectivity for IgG.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xps1ekuw%253D%253D&md5=12d9e97699f387a5f943405a5f682946
150
Bonanni, A.; Chua, C. K.; Zhao, G.; Sofer, Z.; Pumera, M. Inherently Electroactive Graphene Oxide Nanoplatelets As Labels for Single Nucleotide Polymorphism Detection ACS Nano 2012, 6, 8546– 8551 DOI: 10.1021/nn301359y

Google Scholar

150
Inherently electroactive graphene oxide nanoplatelets as labels for single nucleotide polymorphism detection

Bonanni, Alessandra; Chua, Chun Kiang; Zhao, Guanjia; Sofer, Zdenek; Pumera, Martin

ACS Nano (2012), 6 (10), 8546-8551CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Graphene materials are being widely used in electrochem. due to their versatility and excellent properties as platforms for biosensing. However, no records show the use of inherent redox properties of graphene oxide as a label for detection. Here for the first time we used graphene oxide nanoplatelets (GONPs) as electroactive labels for DNA anal. The working signal comes from the redn. of the oxygen-contg. groups present on the surface of GONPs. The different ability of the graphene oxide nanoplatelets to conjugate to DNA hybrids obtained with complementary, noncomplementary, and one-mismatch sequences allows the discrimination of single-nucleotide polymorphism correlated with Alzheimer's disease. We believe that our findings are very important to open a new route in the use of graphene oxide in electrochem.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtlOjt7jJ&md5=570ca1bd0a49cfd57af4cda8fe5b4363
151
Goedert, M.; Spillantini, M. G. A Century of Alzheimer’s Disease Science 2006, 314, 777– 781 DOI: 10.1126/science.1132814

Google Scholar

151
A Century of Alzheimer's Disease

Goedert, Michel; Spillantini, Maria Grazia

Science (Washington, DC, United States) (2006), 314 (5800), 777-781CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

A review. One hundred years ago a small group of psychiatrists described the abnormal protein deposits in the brain that define the most common neurodegenerative diseases. Over the past 25 years, it has become clear that the proteins forming the deposits are central to the disease process. Amyloid-β and tau make up the plaques and tangles of Alzheimer's disease, where these normally sol. proteins assemble into amyloid-like filaments. Tau inclusions are also found in a no. of related disorders. Genetic studies have shown that dysfunction of amyloid-β or tau is sufficient to cause dementia. The ongoing mol. dissection of the neurodegenerative pathways is expected to lead to a true understanding of disease pathogenesis.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XhtFKit73K&md5=6e152685c65d4a08e0b23c0807a35149
152
Li, Q.; Liu, L.; Zhang, S.; Xu, M.; Wang, X.; Wang, C.; Besenbacher, F.; Dong, M. Modulating Aβ_33–42 Peptide Assembly by Graphene Oxide Chem. - Eur. J. 2014, 20, 7236– 7240 DOI: 10.1002/chem.201402022

Google Scholar

152
Modulating Aβ33-42 Peptide Assembly by Graphene Oxide

Li, Qiang; Liu, Lei; Zhang, Shuai; Xu, Meng; Wang, Xueqin; Wang, Chen; Besenbacher, Flemming; Dong, Mingdong

Chemistry - A European Journal (2014), 20 (24), 7236-7240CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)

Graphene oxide (GO) is utilized as the modulator to tune the formation and development of amyloid fibrils (Aβ33-42). Atomic force microscopy temporal evolution measurements reveal that the initial binding between the peptide monomer and the large available surface of the GO sheets can redirect the assembly pathway of amyloid beta. The results support the possibility to develop graphene-based materials to inhibit amyloidosis.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXotV2nsbk%253D&md5=8856344493b93747363a3196941aac09
153
Mahmoudi, M.; Akhavan, O.; Ghavami, M.; Rezaee, F.; Ghiasi, S. M. A. Graphene Oxide Strongly Inhibits Amyloid Beta Fibrillation Nanoscale 2012, 4, 7322– 7325 DOI: 10.1039/c2nr31657a

Google Scholar

153
Graphene oxide strongly inhibits amyloid beta fibrillation

Mahmoudi, Morteza; Akhavan, Omid; Ghavami, Mahdi; Rezaee, Farhad; Ghiasi, Seyyed Mohammad Amin

Nanoscale (2012), 4 (23), 7322-7325CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

Since amyloid beta fibrillation (AβF) plays an important role in the development of neurodegenerative diseases, the authors investigated the effect of graphene oxide (GO) and their protein-coated surfaces on the kinetics of Aβ fibrillation in the aq. soln. The authors showed that GO and their protein-covered surfaces delay the AβF process via adsorption of amyloid monomers. Also, the large available surface of GO sheets can delay the AβF process by adsorption of amyloid monomers. The inhibitory effect of the GO sheet was increased when the authors increase the concn. from 10% (in vitro; stimulated media) to 100% (in vivo; stimulated media). The authors' results revealed that GO and their surface proteins inhibit AβF by decreasing the kinetic reaction.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhvVSmsL3K&md5=427a27a8b3cd7fc0c32f33254d2bc49c
154
Wang, J.; Cao, Y.; Li, Q.; Liu, L.; Dong, M. Size Effect of Graphene Oxide on Modulating Amyloid Peptide Assembly Chem. - Eur. J. 2015, 21, 9632– 9637 DOI: 10.1002/chem.201500577

Google Scholar

154
Size effect of graphene oxide on modulating amyloid peptide assembly

Wang, Jie; Cao, Yunpeng; Li, Qiang; Liu, Lei; Dong, Mingdong

Chemistry - A European Journal (2015), 21 (27), 9632-9637CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)

Protein misfolding and abnormal assembly could lead to aggregates such as oligomer, proto-fibril, mature fibril, and senior amyloid plaques, which are assocd. with the pathogenesis of many amyloid diseases. These irreversible amyloid aggregates typically form in vivo and researchers have been endeavoring to find new modulators to invert the aggregation propensity in vitro, which could increase understanding in the mechanism of the aggregation of amyloid protein and pave the way to potential clin. treatment. Graphene oxide (GO) was shown to be a good modulator, which could strongly control the amyloidosis of Aβ(33-42). In particular, quartz crystal microbalance (QCM), CD spectroscopy, and at. force microscopy (AFM) measurements revealed the size-dependent manner of GO on modulating the assembly of amyloid peptides, which could be a possible way to regulate the self-assembled nanostructure of an amyloid peptide in a predictable manner.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXpt1aqurg%253D&md5=ded3d60518f42c3025755bc393cdcfcc
155
Wahid, M. H.; Stroeher, U. H.; Eroglu, E.; Chen, X.; Vimalanathan, K.; Raston, C. L.; Boulos, R. A. Aqueous Based Synthesis of Antimicrobial-Decorated Graphene J. Colloid Interface Sci. 2015, 443, 88– 96 DOI: 10.1016/j.jcis.2014.11.043

Google Scholar

There is no corresponding record for this reference.
156
Zhou, L.; Jiang, H.; Wei, S.; Ge, X.; Zhou, J.; Shen, J. High-Efficiency Loading of Hypocrellin B on Graphene Oxide for Photodynamic Therapy Carbon 2012, 50, 5594– 5604 DOI: 10.1016/j.carbon.2012.08.013

Google Scholar

156
High-efficiency loading of hypocrellin B on graphene oxide for photodynamic therapy

Zhou, Lin; Jiang, Huijun; Wei, Shaohua; Ge, Xuefeng; Zhou, Jiahong; Shen, Jian

Carbon (2012), 50 (15), 5594-5604CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

A novel hybrid of graphene oxide (GO) and hypocrellin B (HB) was prepd. using a simple noncovalent method. An efficient loading of HB on GO as high as 2 mg/mg was obtained. Mechanism anal. indicated that the π-π stacking interaction is the dominant driving force in the noncovalent interaction between HB and GO. Irradn. of HB and GO hybrid (HB-GO) results in efficient generation of singlet oxygen (1O2). In vitro studies have demonstrated the active uptake of HB-GO into the cytosol of tumor cells. Significant damage to such impregnated tumor cells was obsd. upon irradn.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1Onu7vK&md5=ce22940a0d0a18e7cef3edb6d540f49a
157
Chowdhury, S. M.; Surhland, C.; Sanchez, Z.; Chaudhary, P.; Kumar, M. A. S.; Lee, S.; Peña, L. A.; Waring, M.; Sitharaman, B.; Naidu, M. Graphene Nanoribbons as a Drug Delivery Agent for Lucanthone Mediated Therapy of Glioblastoma Multiforme Nanomedicine 2015, 11, 109– 118 DOI: 10.1016/j.nano.2014.08.001

Google Scholar

157
Graphene nanoribbons as a drug delivery agent for lucanthone mediated therapy of glioblastoma multiforme

Chowdhury, Sayan Mullick; Surhland, Cassandra; Sanchez, Zina; Chaudhary, Pankaj; Suresh Kumar, M. A.; Lee, Stephen; Pena, Louis A.; Waring, Michael; Sitharaman, Balaji; Naidu, Mamta

Nanomedicine (New York, NY, United States) (2015), 11 (1), 109-118CODEN: NANOBF; ISSN:1549-9634. (Elsevier)

PEG-DSPE coated oxidized graphene nanoribbons (O-GNR-PEG-DSPE) were used as agent for delivery of anti-tumor drug Lucanthone (Luc) into Glioblastoma Multiformae (GBM) cells targeting base excision repair enzyme APE-1 (Apurinic endonuclease-1). Lucanthone, an endonuclease inhibitor of APE-1, was loaded onto O-GNR-PEG-DSPEs using a simple non-covalent method. We found its uptake by GBM cell line U251 exceeding 67% and 60% in APE-1-overexpressing U251, post 24 h. However, their uptake was ∼ 38% and 29% by MCF-7 and rat glial progenitor cells (CG-4), resp. TEM anal. of U251 showed large aggregates of O-GNR-PEG-DSPE in vesicles. Luc-O-GNR-PEG-DSPE was significantly toxic to U251 but showed little/no toxicity when exposed to MCF-7/CG-4 cells. This differential uptake effect can be exploited to use O-GNR-PEG-DSPEs as a vehicle for Luc delivery to GBM, while reducing nonspecific cytotoxicity to the surrounding healthy tissue. Cell death in U251 was necrotic, probably due to oxidative degrdn. of APE-1.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVGnsrzJ&md5=6ce714ccb1d173932ed487e13cb0285e
158
Rahmanian, N.; Hamishehkar, H.; Dolatabadid, J. E. N.; Arsalani, N. Nano Graphene Oxide: A Novel Carrier for Oral Delivery of Flavonoids Colloids Surf., B 2014, 123, 331– 338 DOI: 10.1016/j.colsurfb.2014.09.036

Google Scholar

There is no corresponding record for this reference.
159
Liu, Z.; Robinson, J. T.; Sun, X.; Dai, H. PEGylated Nanographene Oxide for Delivery of Water-Insoluble Cancer Drugs J. Am. Chem. Soc. 2008, 130, 10876– 10877 DOI: 10.1021/ja803688x

Google Scholar

159
PEGylated nanographene oxide for delivery of water-insoluble cancer drugs

Liu, Zhuang; Robinson, Joshua T.; Sun, Xiaoming; Dai, Hongjie

Journal of the American Chemical Society (2008), 130 (33), 10876-10877CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

It is known that many potent, often arom. drugs are water insol., which has hampered their use for disease treatment. In this work, we functionalized nanographene oxide (NGO), a novel graphitic material, with branched polyethylene glycol (PEG) to obtain a biocompatible NGO-PEG conjugate stable in various biol. solns., and used them for attaching hydrophobic arom. mols. including a camptothecin (CPT) analog, SN38, noncovalently via π-π stacking. The resulting NGO-PEG-SN38 complex exhibited excellent water soly. while maintaining its high cancer cell killing potency similar to that of the free SN38 mols. in org. solvents. The efficacy of NGO-PEG-SN38 was far higher than that of irinotecan (CPT-11), a FDA-approved water sol. SN38 prodrug used for the treatment of colon cancer. Our results showed that graphene is a novel class of material promising for biol. applications including future in vivo cancer treatment with various arom., low-soly. drugs.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXptVCqu78%253D&md5=6e96b6929256966ec9ca88aca0805f8b
160
Georgakilas, V.; Kouloumpis, A.; Gournis, D.; Bourlinos, A.; Trapalis, C.; Zboril, R. Tuning the Dispersibility of Carbon Nanostructures from Organophilic to Hydrophilic: Towards the Preparation of New Multipurpose Carbon-Based Hybrids Chem. - Eur. J. 2013, 19, 12884– 12891 DOI: 10.1002/chem.201301200

Google Scholar

160
Tuning the Dispersibility of Carbon Nanostructures from Organophilic to Hydrophilic: towards the Preparation of New Multipurpose Carbon-Based Hybrids

Georgakilas, Vasilios; Kouloumpis, Antonios; Gournis, Dimitrios; Bourlinos, Athanasios; Trapalis, Christos; Zboril, Radek

Chemistry - A European Journal (2013), 19 (38), 12884-12891CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)

The hydroxyphenyl derivs. of carbon nanostructures (graphene and carbon nanotubes) can be easily transformed into highly organophilic or hydrophilic derivs. by using the ionic interactions between the phenolic groups and oleylamine or tetramethylammonium hydroxide, resp. The products were finely dispersed in homo-polymers or block co-polymers to create homogeneous carbon-based nanocomposites and were used as nanocarriers for the dispersion and protection of strongly hydrophobic compds., such as large arom. chromophores or anticancer drugs in aq. solns.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht1Crt73P&md5=02890bdb4b5b05e5c7dc6fbc5e202b9c
161
Balcioglu, M.; Rana, M.; Yigit, M. V. Doxorubicin Loading on Graphene Oxide, Iron Oxide and Gold Nanoparticle Hybrid J. Mater. Chem. B 2013, 1, 6187– 6193 DOI: 10.1039/c3tb20992j

Google Scholar

161
Doxorubicin loading on graphene oxide, iron oxide and gold nanoparticle hybrid

Balcioglu, Mustafa; Rana, Muhit; Yigit, Mehmet V.

Journal of Materials Chemistry B: Materials for Biology and Medicine (2013), 1 (45), 6187-6193CODEN: JMCBDV; ISSN:2050-7518. (Royal Society of Chemistry)

We report the facile and non-covalent construction of a graphene oxide-based functional hybrid material with gold and fluorescently labeled superparamagnetic iron oxide nanoparticles [GO-MNcy5.5-AuNP]. The obtained [GO-MNcy5.5-AuNP] hybrid exhibits the phys. properties of each component. The relaxivity of the magnetic nanoparticles was improved, cy5.5 fluorescence was completely quenched and the surface plasmon peak of the gold nanoparticles at 520 nm was obsd. in the hybrid complex. The hybrid exhibits an ultra-high doxorubicin loading capacity of 6.05 mg mg-1 at 0.32 mg ml-1 drug concn. This material could serve as a promising platform for theranostics, due to its contrast agent compn. and anticancer drug loading capacity.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslWms7zP&md5=da65d34c822999c0664efe9004ae5ec6
162
Koninti, R. K.; Sengupta, A.; Gavvala, K.; Ballav, N.; Hazra, P. Loading of an Anti-Cancer Drug onto Graphene Oxide and Subsequent Release to DNA/RNA: A Direct Optical Detection Nanoscale 2014, 6, 2937– 2944 DOI: 10.1039/c3nr06081k

Google Scholar

There is no corresponding record for this reference.
163
Chia, J. S. Y.; Tan, M. T. T.; Khiew, P. S.; Chin, J. K.; Siong, C. W. A Bio-Electrochemical Sensing Platform for Glucose Based on Irreversible, Non-Covalent pi–pi Functionalization of Graphene Produced via a Novel, Green Synthesis Method Sens. Actuators, B 2015, 210, 558– 565 DOI: 10.1016/j.snb.2015.01.023

Google Scholar

163
A bio-electrochemical sensing platform for glucose based on irreversible, non-covalent pi-pi functionalization of graphene produced via a novel, green synthesis method

Chia, Joanna Su Yuin; Tan, Michelle T. T.; Khiew, Poi Sim; Chin, Jit Kai; Siong, Chiu Wee

Sensors and Actuators, B: Chemical (2015), 210 (), 558-565CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)

In this work, pristine graphene was produced through a novel single step exfoliation of graphite in mild sonochem. alc.-water treatment. The developed green synthesis approach successfully eradicates issues assocd. with conventional methods which use org. solvents, acids and oxidizers, leaving undesirable functional groups attached to the graphene surface. Results from cyclic voltammetry and amperometric anal. showed a wide linear range up to 5 mM and sensitivity improvements of more than 22 times in comparison to the control sample. Subsequently, an electrochem. glucose biosensor was fabricated by the immobilization of glucose oxidase (GOx) via bi-functional linkers. This reliable surface modification method provides irreversible non-covalent bonding between graphene and the enzymic amide groups, while preserving the sp2 graphene structure, while promoting better electron transfer kinetics between the FAD/FADH2 redox sites of GOx at the modified electrode surface. The fabricated biosensor exhibited satisfactory long-term stability, reproducibility and high selectivity for glucose detection and showed significant improvements when compared to unmodified electrodes.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXht1Ogu7w%253D&md5=465a7b517ebee49162ae027748c75d7f
164
Kong, N.; Liua, J.; Kong, Q.; Wang, R.; Barrow, C. J.; Yang, W. Graphene Modified Gold Electrode via Stacking Interaction for Analysis of Cu²⁺ and Pb²⁺ Sens. Actuators, B 2013, 178, 426– 433 DOI: 10.1016/j.snb.2013.01.009

Google Scholar

164
Graphene modified gold electrode via π-π stacking interaction for analysis of Cu2+ and Pb2+

Kong, Na; Liu, Jingquan; Kong, Qingshan; Wang, Rui; Barrow, Colin J.; Yang, Wenrong

Sensors and Actuators, B: Chemical (2013), 178 (), 426-433CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)

A gold electrode modified with graphene via non-covalent interaction for a chem. sensor is presented. The gold electrode was first modified with carboxylic acid functionalities, followed by the immobilization of pyrene groups via the esterification reaction. The freshly prepd. graphene nanosheets were then attached on the electrode surface via π-π stacking interaction for the anal. of Cu2+ and Pb2+. The graphene modified gold electrode exhibited enhanced anal. sensitivity toward Cu2+ and Pb2+. The linear detection range for Cu2+ anal. is 1.5-20 nM and Pb2+ is 0.4-20 nM. Good reusability and repeatability were also obsd.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXivFCku78%253D&md5=195d0670a25c56c347596b2aab5102f9
165
Shen, X.; Liu, Y.; Pang, Y.; Yao, W. Conjugation of Graphene on Au Surface by π–π Interaction and Click Chemistry Electrochem. Commun. 2013, 30, 13– 16 DOI: 10.1016/j.elecom.2013.01.025

Google Scholar

There is no corresponding record for this reference.
166
Zhang, S.; Tang, S.; Lei, J.; Dong, H.; Ju, H. Functionalization of Graphene Nanoribbons with Porphyrin for Electrocatalysis and Amperometric Biosensing J. Electroanal. Chem. 2011, 656, 285– 288 DOI: 10.1016/j.jelechem.2010.10.005

Google Scholar

166
Functionalization of graphene nanoribbons with porphyrin for electrocatalysis and amperometric biosensing

Zhang, Siyuan; Tang, Sheng; Lei, Jianping; Dong, Haifeng; Ju, Huangxian

Journal of Electroanalytical Chemistry (2011), 656 (1-2), 285-288CODEN: JECHES; ISSN:1873-2569. (Elsevier B.V.)

A direct electrochem. method to reduce graphene oxide nanoribbons is proposed. The reduced graphene nanoribbons (RGNRs) could be functionalized with water-sol. Fe(III) meso-tetrakis(N-methylpyridinum-4-yl)porphyrin (FeTMPyP) via π-π noncovalent interaction on electrode surface. The resulting FeTMPyP/RGNRs film showed excellent electrocatalysis toward the redn. of dissolved O at peak potential of -0.28 V Using glucose oxidase as model enzyme, a biosensor based on the consumption of O2 was developed for amperometric detection of glucose ranging from 0.5 mM to 10 mM. This biosensor could be successfully applied in the detection of glucose in human serum. The FeTMPyP functionalized RGNRs provided a platform for electrocatalysis and biosensing of oxidase substrates.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXmtVWqtbg%253D&md5=3a26255e9636475c800bf0309142db79
167
Srinivasan, S.; Je, S. H.; Back, S.; Barin, G.; Buyukcakir, O.; Guliyev, R.; Jung, Y.; Coskun, A. Ordered Supramolecular Gels Based on Graphene Oxide and Tetracationic Cyclophanes Adv. Mater. 2014, 26, 2725– 2729 DOI: 10.1002/adma.201304334

Google Scholar

There is no corresponding record for this reference.
168
Georgakilas, V.; Perman, J. A.; Tucek, J.; Zboril, R. Broad Family of Carbon Nanoallotropes – Classification, Chemistry and Advanced Architecture of Fullerene, Nanotube, Graphene and their Relatives Chem. Rev. 2015, 115, 4744– 4822 DOI: 10.1021/cr500304f

Google Scholar

There is no corresponding record for this reference.
169
Shao, Q.; Tang, J.; Lin, Y.; Li, J.; Qin, F.; Yuan, J.; Qin, L. C. Carbon Nanotube Spaced Graphene Aerogels with Enhanced Capacitance in Aqueous and Ionic Liquid Electrolytes J. Power Sources 2015, 278, 751– 759 DOI: 10.1016/j.jpowsour.2014.12.052

Google Scholar

169
Carbon nanotube spaced graphene aerogels with enhanced capacitance in aqueous and ionic liquid electrolytes

Shao, Qingguo; Tang, Jie; Lin, Yuexian; Li, Jing; Qin, Faxiang; Yuan, Jinshi; Qin, Lu-Chang

Journal of Power Sources (2015), 278 (), 751-759CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)

Carbon nanotube spaced graphene aerogels have been prepd. by a hydrothermal method and used for supercapacitor applications. The sp. surface area and specific capacitance can be controlled by tuning the amt. of added carbon nanotubes. The as-prepd. composite aerogels retain the advantage of aerogel structure in providing macropores to ensure electrodes fast wetted by the electrolyte ions and also possess addnl. mesopores created by the carbon nanotube spacers for more ion adsorption. Benefited from that, the composite aerogels exhibit significantly enhanced supercapacitor properties in both aq. and ionic liq. electrolyte. Compared with graphene aerogels, the composite aerogels show a 37% larger specific capacitance of 245.5 F g-1 at a c.d. of 2.5 A g-1 and high rate capability of 197.0 F g-1 at a high c.d. of 80 A g-1 in aq. electrolyte. Moreover, the composite aerogels deliver a 33% larger specific capacitance of 183.3 F g-1 at 0.5 A g-1 and a high energy d. of 80 Wh kg-1 when using an ionic liq. (EMIMBF4) as the electrolyte.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFOmsrfK&md5=a7ea347381a67369ad5a759d104ad822
170
Georgakilas, V.; Demeslis, A.; Ntararas, E.; Kouloumpis, A.; Dimos, K.; Gournis, D.; Kocman, M.; Otyepka, M.; Zboril, R. Hydrophilic Nanotube Supported Graphene-Water Dispersible Carbon Superstructure with Excellent Conductivity Adv. Funct. Mater. 2015, 25, 1481– 1487 DOI: 10.1002/adfm.201403801

Google Scholar

170
Hydrophilic Nanotube Supported Graphene-Water Dispersible Carbon Superstructure with Excellent Conductivity

Georgakilas, Vasilios; Demeslis, Athanasios; Ntararas, Evangelos; Kouloumpis, Antonios; Dimos, Konstantinos; Gournis, Dimitrios; Kocman, Mikulas; Otyepka, Michal; Zboril, Radek

Advanced Functional Materials (2015), 25 (10), 1481-1487CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

In this work, it is shown that the hydrophilic functionalized multiwall carbon nanotubes (MWCNs) can stabilize a large amt. of pristine graphene nanosheets in pure water without the assistance of surfactants, ionic liqs., or hydrophilic polymers. Role of stabilizer is conveyed by highly hydrophilic carbon nanotubes, functionalized by dihydroxy Ph groups, affording a stable dispersion at concns. as high as 15 mg mL-1. Such multidimensional (2D/1D) graphene/MWCN hybrid is found to be dispersible also in other polar org. solvents such as ethanol, isopropanol, N,N-dimethylformamide, ethylene glycol, and their mixts. High-resoln. transmission microscopy and at. force microscopy (AFM) including a liq. mode AFM manifest several types of interaction including trapping of multiwalled carbon nanotubes between the graphene sheets or the modification of graphene edges. Mol. dynamic simulations show that formation of an assembly is kinetically controlled. Importantly, the hybrid can be deposited on the paper by drop casting or dispersed in water-sol. polymers resulting in record values of elec. cond. (sheet resistance up to Rs ≈ 25 Ω sq-1 for free hybrid material and Rs ≈ 1300 Ω sq-1 for a polyvinilalc./hybrid composite film). Thus, these novel water dispersible carbon superstructures reveal a high application potential as conductive inks for inkjet printing or as highly conductive polymers.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXosFKktQ%253D%253D&md5=36000c5625e0be1a46c580feaf61e2ed
171
Tang, C.; Long, G.; Hu, X.; Wong, K.; Lau, W. M.; Fan, M.; Mei, J.; Xu, T.; Wang, B.; Huid, D. Conductive Polymer Nanocomposites with Hierarchical Multi-Scale Structures via Self-Assembly of Carbon-Nanotubes on Graphene on Polymer-microspheres Nanoscale 2014, 6, 7877– 7888 DOI: 10.1039/c3nr06056j

Google Scholar

171
Conductive polymer nanocomposites with hierarchical multi-scale structures via self-assembly of carbon-nanotubes on graphene on polymer-microspheres

Tang, Changyu; Long, Gucheng; Hu, Xin; Wong, Ka-wai; Lau, Woon-ming; Fan, Meikun; Mei, Jun; Xu, Tao; Wang, Bin; Hui, David

Nanoscale (2014), 6 (14), 7877-7888CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

A novel and highly conductive 3-dimensional (3D) hierarchical multi-scale structure is formed by a new, simple, facile, and water-based method that enables practical prodn. of conductive carbon nanofiller/polymer composites. More specifically, the π-π interaction between CNTs and graphene oxide (GO) is exploited to disperse conductive but non-polar CNTs with amphiphilic GO sheets to form a stable aq. colloidal soln. Aq.-dispersible latex-polystyrene microspheres are then added to enable the self-assembly processes of anchoring CNTs on GO and wrapping microspheres with GO-stabilized CNTs for the formation of an intriguing 3D hierarchical multi-scale structure. During this process, GO is reduced to conductive reduced-graphene oxide (RGO). The resultant RGO sheets act as 'nano-walls' to prevent CNTs from randomly diffusing into the polymer bulk during thermal pressing of RGO-CNT/microspheres, which results in the formation of a 3D foam-like network of RGO-CNTs with high quality. The resultant composite with such a structure gives an ultra-low percolation threshold (0.03 vol% RGO-CNTs) and a reasonably high cond. (153 S m-1 at 4 vol% RGO-CNTs), which could satisfy various applications requiring both transparency and elec. conduction characteristics (e.g. transparent antistatic coatings, capacitive touch-screens, and transparent electronic devices).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVKjtr%252FO&md5=9acb5c6399f254e22d3ffd591dfbca6c
172
Li, G.; Shrotriya, V.; Huang, J. S.; Yao, Y.; Moriarty, T.; Emery, K.; Yang, Y. High-Efficiency Solution Processable Polymer Photovoltaic Cells by Self-Organization of Polymer Blends Nat. Mater. 2005, 4, 864– 868 DOI: 10.1038/nmat1500

Google Scholar

172
High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends

Li, Gang; Shrotriya, Vishal; Huang, Jinsong; Yao, Yan; Moriarty, Tom; Emery, Keith; Yang, Yang

Nature Materials (2005), 4 (11), 864-868CODEN: NMAACR; ISSN:1476-1122. (Nature Publishing Group)

Converting solar energy into electricity provides a much-needed soln. to the energy crisis the world is facing today. Polymer solar cells showed potential to harness solar energy in a cost-effective way. Significant efforts are underway to improve their efficiency to the level of practical applications. Here, the authors report highly efficient polymer solar cells based on a bulk heterojunction of polymer poly(3-hexylthiophene) and methanofullerene. Controlling the active layer growth rate results in an increased hole mobility and balanced charge transport. Together with increased absorption in the active layer, this results in much-improved device performance, particularly in external quantum efficiency. The power-conversion efficiency of 4.4% achieved here is the highest published so far for polymer-based solar cells. The soln. process involved ensures that the fabrication cost remains low and the processing is simple. The high efficiency achieved in this work brings these devices one step closer to commercialization.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXht1ShsbnO&md5=8bf7c1bf188a6b0b96a895552a90fe22
173
Kim, J. Y.; Lee, K.; Coates, N. E.; Moses, D.; Nguyen, T. Q.; Dante, M.; Heeger, A. J. Efficient Tandem Polymer Solar Cells Fabricated by All-Solution Processing Science 2007, 317, 222– 225 DOI: 10.1126/science.1141711

Google Scholar

173
Efficient Tandem Polymer Solar Cells Fabricated by All-Solution Processing

Kim, Jin Young; Lee, Kwanghee; Coates, Nelson E.; Moses, Daniel; Nguyen, Thuc-Quyen; Dante, Mark; Heeger, Alan J.

Science (Washington, DC, United States) (2007), 317 (5835), 222-225CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

Tandem solar cells, in which two solar cells with different absorption characteristics are linked to use a wider range of the solar spectrum, were fabricated with each layer processed from soln. using bulk heterojunction materials comprising semiconducting polymers and fullerene derivs. A transparent titanium oxide (TiOx) layer separates and connects the front cell and the back cell. The TiOx layer serves as an electron transport and collecting layer for the 1st cell and as a stable foundation that enables the fabrication of the 2nd cell to complete the tandem cell architecture. The authors use an inverted structure with the low band-gap polymer-fullerene composite as the charge-sepg. layer in the front cell and the high band-gap polymer composite as that in the back cell. Power-conversion efficiencies of >6% were achieved at illuminations of 200 mW per square centimeter.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXnsFaqtr4%253D&md5=ca755156c911cdd36928e67976822375
174
Guenes, S.; Neugebauer, H.; Sariciftci, N. S. Conjugated Polymer-Based Organic Solar Cells Chem. Rev. 2007, 107, 1324– 1338 DOI: 10.1021/cr050149z

Google Scholar

There is no corresponding record for this reference.
175
Kim, Y.; Cook, S.; Tuladhar, S. M.; Choulis, S. A.; Nelson, J.; Durrant, R. J.; Bradley, D. D. C.; Giles, M.; Mcculloch, I.; Ha, C. S. A Strong Regioregularity Effect in Self-Organizing Conjugated Polymer Films and High-Efficiency Polythiophene: Fullerene Solar Cells Nat. Mater. 2006, 5, 197– 203 DOI: 10.1038/nmat1574

Google Scholar

175
A strong regioregularity effect in self-organizing conjugated polymer films and high-efficiency polythiophene:fullerene solar cells

Kim, Youngkyoo; Cook, Steffan; Tuladhar, Sachetan M.; Choulis, Stelios A.; Nelson, Jenny; Durrant, James R.; Bradley, Donal D. C.; Giles, Mark; McCulloch, Iain; Ha, Chang-Sik; Ree, Moonhor

Nature Materials (2006), 5 (3), 197-203CODEN: NMAACR; ISSN:1476-1122. (Nature Publishing Group)

Low-cost photovoltaic energy conversion using conjugated mol. materials has become increasingly feasible through the development of org. Bulk heterojunction (BHJ) structures, where efficient light-induced charge sepn. is enabled by a large-area donor-acceptor interface. The highest efficiencies were achieved using blends of poly(3-hexylthiophene) (P3HT) and a fullerene deriv., but performance depends critically on the material properties and processing conditions. This variability is believed to be influenced by the self-organizing properties of P3HT, which means that both optical and electronic properties are sensitive to the mol. packing. However, the relation between mol. nanostructure, optoelectronic properties of the blend material and device performance has not yet been demonstrated. Here the authors focus on the influence of polymer regioregularity (RR) on the mol. nanostructure, and hence on the resulting material properties and device performance. The authors find a strong influence of RR on solar-cell performance, which can be attributed to enhanced optical absorption and transport resulting from the organization of P3HT chains and domains. Further optimization of devices using the highest RR material resulted in a power conversion efficiency of 4.4%, even without optimization of electrodes.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XhvV2ju7k%253D&md5=403a8eec83802fddd8ebd93a935b61b9
176
Qu, S.; Li, M.; Xie, L.; Huang, X.; Yang, J.; Wang, N.; Yang, S. Noncovalent Functionalization of Graphene Attaching [6,6]-Phenyl-C₆₁-butyric Acid Methyl Ester (PCBM) and Application as Electron Extraction Layer of Polymer Solar Cells ACS Nano 2013, 7, 4070– 4081 DOI: 10.1021/nn4001963

Google Scholar

176
Noncovalent functionalization of graphene attaching [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and application as electron extraction layer of polymer solar cells

Qu, Shuxuan; Li, Minghua; Xie, Lixin; Huang, Xiao; Yang, Jinguo; Wang, Nan; Yang, Shangfeng

ACS Nano (2013), 7 (5), 4070-4081CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

A new graphene-fullerene composite (rGO-pyrene-PCBM), in which [6,6]-phenyl-C61-butyric acid Me ester (PCBM) was attached onto reduced graphene oxide (rGO) via the noncovalent functionalization approach, was reported. The pyrene-PCBM moiety was synthesized via a facile esterification reaction, and pyrene was used as an anchoring bridge to link rGO and PCBM components. FTIR, UV-vis, and XPS spectroscopic characterizations were carried out to confirm the hybrid structure of rGO-pyrene-PCBM, and the composite formation is found to improve greatly the dispersity of rGO in DMF. The geometric configuration of rGO-pyrene-PCBM was studied by Raman, SEM, and AFM analyses, suggesting that the C60 moiety is far from the graphene sheet and is bridged with the graphene sheet via the pyrene anchor. Finally rGO-pyrene-PCBM was successfully applied as electron extn. layer for P3HT:PCBM bulk heterojunction polymer solar cell (BHJ-PSC) devices, affording a PCE of 3.89%, which is enhanced by ca. 15% compared to that of the ref. device without electron extn. layer (3.39%). Contrarily, the comparative devices incorporating the rGO or pyrene-PCBM component as electron extn. layer showed dramatically decreased PCE, indicating the importance of composite formation between rGO and pyrene-PCBM components for its electron extn. property.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXmtVymtLw%253D&md5=1fda5dc3f9a13228b984a46a000f4d01
177
Gan, T.; Hu, C.; Sun, Z.; Hu, S. Facile Synthesis of Water-Soluble Fullerene–Graphene Oxide Composites for Electrodeposition of Phosphotungstic Acid-Based Electrocatalysts Electrochim. Acta 2013, 111, 738– 745 DOI: 10.1016/j.electacta.2013.08.059

Google Scholar

177
Facile synthesis of water-soluble fullerene-graphene oxide composites for electrodeposition of phosphotungstic acid-based electrocatalysts

Gan, Tian; Hu, Chengguo; Sun, Zhe; Hu, Shengshui

Electrochimica Acta (2013), 111 (), 738-745CODEN: ELCAAV; ISSN:0013-4686. (Elsevier Ltd.)

A versatile approach to the dispersion of C60/C70 in water with high concn. and stability by graphene oxide (GO) was reported here. By simply grinding with GO, C60/C70 can be readily dissolved in water with soly. up to 5 mg mL-1 and stability for more than three months. TEM indicated that C60/C70 formed a uniform and high-d. layer on the surface of GO, which may be achieved through the strong π-π interaction between fullerenes and GO, as supported by Fourier transform IR spectroscopy, Raman and UV-visible spectroscopy spectra. Through a simple electrodeposition method, two novel phosphotungstic acid-graphene oxide-fullerene hybrids (i.e., PTA-GO-C60 and PTA-GO-C70) were formed on glassy carbon electrodes. The resulting hybrid modified electrodes exhibited enhanced electrocatalytic activity for the oxidn. of a variety of small biomols., including dopamine, ascorbic acid, uric acid, L-tryptophan, tyrosine, indole-3-acetic acid, salicylic acid and 6-benzylaminopurine, reflected by the remarkably enlarged peak currents and apparently reduced oxidn. overpotentials as compared with those on either PTA or PTA-GO modified electrodes.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslCqs7vL&md5=9b6854ebe9e6c620fad9be9e25b5000f
178
Ba, H.; Podila, S.; Liu, Y.; Mua, X.; Nhuta, J. M.; Papaefthimiou, V.; Zafeiratos, S.; Granger, P.; Huu, C. P. Nanodiamond Decorated Few-Layer Graphene Composite as Anefficient Metal-Free Dehydrogenation Catalyst for Styrene Production Catal. Today 2015, 249, 167– 175 DOI: 10.1016/j.cattod.2014.10.029

Google Scholar

178
Nanodiamond decorated few-layer graphene composite as an efficient metal-free dehydrogenation catalyst for styrene production

Ba, Housseinou; Podila, Seetharamulu; Liu, Yuefeng; Mu, Xiaoke; Nhut, Jean-Mario; Papaefthimiou, Vasiliki; Zafeiratos, Spyridon; Granger, Pascal; Pham-Huu, Cuong

Catalysis Today (2015), 249 (), 167-175CODEN: CATTEA; ISSN:0920-5861. (Elsevier B.V.)

Hybrid materials consisting of graphene and nanodiamonds (NDs) can potentially display not only the individual properties of ND and graphene, but also those resulting from synergism when they closely interact. Herein, synergistic effects between ND and few-layer-graphene (FLG) contg. between 5 and 20 layers of graphene are examd. The ND/FLG composite was prepd. by mixing a suspension of FLG in ethanol with NDs. In this case, FLG plays the role of 2D support for dispersing ND clusters while NDs acting as a nano-spacer for partly preventing the re-stacking of the FLG sheets. The as-synthesized hybrid material was further used as metal-free catalyst for the steam-free direct dehydrogenation (DH) of ethylbenzene (EB) to styrene (ST). The DH activity obtained on the ND/FLG catalyst was benchmarked with other catalysts, i.e. com. K-promoted Fe-based catalysts and carbon-based catalysts. The ND/FLG catalyst exhibits the highest DH activity among the tested catalysts, esp. with a dehydrogenation specific rate as high as 19 mmolST g-1ND h-1 along with a selectivity toward styrene up to 95% at reaction temp. at 600°C. The catalyst displays a relatively high stability as a function of time on stream while the deactivated catalyst can be easily regenerated by an oxidative treatment in mild temp. conditions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFWisrrM&md5=a5919f272e2bad21f67497aa0d8aab1a
179
Pastor, I. R.; Fernandez, G. R.; Rizo, H. V.; Terrones, M.; Gullon, I. M. Towards the Understanding of the Graphene Oxide Structure: How to Control the Formation of Humic- and Fulvic-Like Oxidized Debris Carbon 2015, 84, 299– 309 DOI: 10.1016/j.carbon.2014.12.027

Google Scholar

There is no corresponding record for this reference.
180
Rourke, J. P.; Pandey, P. A.; Moore, J. J.; Bates, M.; Kinloch, I. A.; Young, R. J.; Wilson, N. R. The Real Graphene Oxide Revealed: Stripping the Oxidative Debris from the Graphene Like Sheets Angew. Chem., Int. Ed. 2011, 50, 3173– 3177 DOI: 10.1002/anie.201007520

Google Scholar

There is no corresponding record for this reference.
181
Thomas, H. R.; Valles, C.; Young, R. J.; Kinloch, I. A.; Wilson, N. R.; Rourke, J. P. Identifying the Fluorescence of Graphene Oxide J. Mater. Chem. C 2013, 1, 338– 342 DOI: 10.1039/C2TC00234E

Google Scholar

181
Identifying the fluorescence of graphene oxide

Thomas, Helen R.; Valles, Cristina; Young, Robert J.; Kinloch, Ian A.; Wilson, Neil R.; Rourke, Jonathan P.

Journal of Materials Chemistry C: Materials for Optical and Electronic Devices (2013), 1 (2), 338-342CODEN: JMCCCX; ISSN:2050-7534. (Royal Society of Chemistry)

Treatment of graphene oxide (GO) with NaOH separates the material into 2 components: a colorless, but highly fluorescent, oxidative debris and a darker nonfluorescent material contg. the graphene-like sheets. The as-produced GO shows a weak, broad luminescence while the oxidative debris fluoresces more intensely, blue-shifted relative to the as-produced GO, with a dispersive emission profile shifting to lower wavelength as the excitation wavelength is decreased. Such excitation wavelength dependent luminescence is characteristic of ensembles of nm-sized C-based fluorophores. Anal. of the fluorescence as a function of excitation wavelength for as-produced graphene oxide shows a single nondispersive peak, consistent with broadening of the emission from a single species rather than an ensemble of quantum dots within the graphene sheet.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhvVWgsrrE&md5=be9946164f459b455b22cfea3d46fbd0
182
Bonanni, A.; Ambrosi, A.; Chua, C. K.; Pumera, M. Oxidation Debris in Graphene Oxide Is Responsible for Its Inherent Electroactivity ACS Nano 2014, 8, 4197– 4204 DOI: 10.1021/nn404255q

Google Scholar

182
Oxidation Debris in Graphene Oxide Is Responsible for Its Inherent Electroactivity

Bonanni, Alessandra; Ambrosi, Adriano; Chua, Chun Kiang; Pumera, Martin

ACS Nano (2014), 8 (5), 4197-4204CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Graphene oxide is known to exhibit many interesting properties, ranging from inherent fluorescence to inherent electrochem., just to name a few. Recent research found that graphene oxide is a composite material consisting of the so-called oxidn. debris and unoxidized graphene fragments. Surprisingly, the oxidn. debris, which contains small and highly oxidized arom. fragments adsorbed on graphene surfaces, is responsible for the excellent soly. and inherent fluorescence of graphene oxide. Here, the authors examine the origin of the inherent electroactivity of graphene oxide and demonstrate that such phenomenon is attributed to the presence of oxidn. debris. The authors sep. oxidn. debris from the less oxidized graphene backbone in as-prepd. graphene oxide nanoplatelets using ultrasonication. The extension of ultrasonication time corresponded to a larger amt. of oxidn. debris released from the graphene oxide nanoplatelets' surfaces and subsequently caused detrimental effects to the inherent electroactivity of the graphene material. Since graphene oxide is often the material of choice for energy storage devices, such as batteries and supercapacitors, a thorough understanding on the origin of such inherent electrochem. properties of graphene oxide is of very high importance.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXntFOmtbw%253D&md5=b8a85a4c2411adc4ae6065b29bde8f54
183
Coluci, V. R.; Martinez, D. S. T.; Honório, J. G.; de Faria, A. F.; Morales, D. A.; Skaf, M. S.; Alves, O. L.; Umbuzeiro, G. A. Noncovalent Interaction with Graphene Oxide: The Crucial Role of Oxidative Debris J. Phys. Chem. C 2014, 118, 2187– 2193 DOI: 10.1021/jp409501g

Google Scholar

183
Noncovalent Interaction with Graphene Oxide: The Crucial Role of Oxidative Debris

Coluci, Vitor R.; Martinez, Diego Stefani T.; Honorio, Jaqueline G.; de Faria, Andreia F.; Morales, Daniel A.; Skaf, Munir S.; Alves, Oswaldo L.; Umbuzeiro, Gisela A.

Journal of Physical Chemistry C (2014), 118 (4), 2187-2193CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)

Graphene oxide (GO) is a very promising material because it is easy to process, water-sol., and chem. versatile due to the presence of oxygenated groups on its surface. GO has been used in different areas such as electronics, biosensing, and environmental remediation. To design efficient materials, esp. for biosensing and for remediating pollutants, the knowledge of surface noncovalent interaction and functionalization is crucial. Recently, it has been suggested revisions on the structural models of GO because the presence of highly oxidized polyarom. carboxylated fragments (oxidative debris) on the GO surfaces. These debris are produced during acid treatments commonly employed in GO synthesis and purifn. Here we applied chem. anal., bioassays, and atomistic simulations to study the influence of oxidative debris on the noncovalent interaction of GO sheets with an important org. pollutant (e.g., 1-nitropyrene). GO samples without oxidative debris were found to be 75% more effective to adsorb 1-nitropyrene than samples with debris. Our results suggest that small (∼1 nm) oxidative debris are responsible for preventing adsorption sites on GO surfaces from being reached by potentially adsorbate mols.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXlslCrtQ%253D%253D&md5=9f5c64a2ec930459611aec874a64ed18
184
Gupta, A.; Sakthivel, T.; Seal, S. Recent Development in 2D Materials beyond Graphene Prog. Mater. Sci. 2015, 73, 44– 126 DOI: 10.1016/j.pmatsci.2015.02.002

Google Scholar

184
Recent development in 2D materials beyond graphene

Gupta, Ankur; Sakthivel, Tamilselvan; Seal, Sudipta

Progress in Materials Science (2015), 73 (), 44-126CODEN: PRMSAQ; ISSN:0079-6425. (Elsevier Ltd.)

Discovery of graphene and its astonishing properties have given birth to a new class of materials known as "2D materials". Motivated by the success of graphene, alternative layered and non-layered 2D materials have become the focus of intense research due to their unique phys. and chem. properties. Origin of these properties ascribed to the dimensionality effect and modulation in their band structure. This review highlights the recent progress of the state-of-the-art research on synthesis, characterization and isolation of single and few layer nanosheets and their assembly. Electronic, magnetic, optical and mech. properties of 2D materials have also been reviewed for their emerging applications in the area of catalysis, electronic, optoelectronic and spintronic devices; sensors, high performance electrodes and nanocomposites. Finally this review concludes with a future prospective to guide this fast evolving class of 2D materials in next generation materials science.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlt1equ7k%253D&md5=c9b5cf4e5e46142d86afc19276ea8048
185
Wang, Q. H.; Kalantar-Zadeh, K.; Kis, A.; Coleman, J. N.; Strano, M. S. Electronics and Optoelectronics of Two Dimensional Transition Metal Dichalcogenides Nat. Nanotechnol. 2012, 7, 699– 712 DOI: 10.1038/nnano.2012.193

Google Scholar

185
Electronics and optoelectronics of two-dimensional transition metal dichalcogenides

Wang, Qing Hua; Kalantar-Zadeh, Kourosh; Kis, Andras; Coleman, Jonathan N.; Strano, Michael S.

Nature Nanotechnology (2012), 7 (11), 699-712CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)

A review. The remarkable properties of graphene have renewed interest in inorg., two-dimensional materials with unique electronic and optical attributes. Transition metal dichalcogenides (TMDCs) are layered materials with strong in-plane bonding and weak out-of-plane interactions enabling exfoliation into two-dimensional layers of single unit cell thickness. Although TMDCs were studied for decades, recent advances in nanoscale materials characterization and device fabrication have opened up new opportunities for two-dimensional layers of thin TMDCs in nanoelectronics and optoelectronics. TMDCs such as MoS2, MoSe2, WS2 and WSe2 have sizable bandgaps that change from indirect to direct in single layers, allowing applications such as transistors, photodetectors and electroluminescent devices. The authors review the historical development of TMDCs, methods for prepg. atomically thin layers, their electronic and optical properties, and prospects for future advances in electronics and optoelectronics.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1ajtr7P&md5=4e45d586c6ac7b0676a461f61a53db68
186
Splendiani, A.; Sun, L.; Zhang, Y.; Li, T.; Kim, J.; Chim, C. Y.; Galli, G.; Wang, F. Emerging Photoluminescence in Monolayer MoS₂ Nano Lett. 2010, 10, 1271– 1275 DOI: 10.1021/nl903868w

Google Scholar

186
Emerging Photoluminescence in Monolayer MoS2

Splendiani, Andrea; Sun, Liang; Zhang, Yuanbo; Li, Tianshu; Kim, Jonghwan; Chim, Chi-Yung; Galli, Giulia; Wang, Feng

Nano Letters (2010), 10 (4), 1271-1275CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Novel phys. phenomena can emerge in low-dimensional nanomaterials. Bulk MoS2, a prototypical metal dichalcogenide, is an indirect bandgap semiconductor with negligible photoluminescence. When the MoS2 crystal is thinned to monolayer, however, a strong photoluminescence emerges, indicating an indirect to direct bandgap transition in this d-electron system. Quantum confinement in layered d-electron materials like MoS2 provides new opportunities for engineering the electronic structure of matter at the nanoscale.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXjt1Sqsbs%253D&md5=7df269b35ce26d97dd8fbec1d8b6117d
187
Thripuranthaka, M.; Late, D. J. Temperature Dependent Phonon Shifts in Single-Layer WS₂ ACS Appl. Mater. Interfaces 2014, 6, 1158– 1163 DOI: 10.1021/am404847d

Google Scholar

There is no corresponding record for this reference.
188
Miremadi, B. K.; Morrison, S. R. High Activity Catalyst from Exfoliated MoS₂ J. Catal. 1987, 103, 334– 345 DOI: 10.1016/0021-9517(87)90125-4

Google Scholar

188
High activity catalyst from exfoliated molybdenum disulfide

Miremadi, Bijan K.; Morrison, S. Roy

Journal of Catalysis (1987), 103 (2), 334-45CODEN: JCTLA5; ISSN:0021-9517.

Unusually high activity catalysts were prepd. by using exfoliated MoS2 suspended as single layers in soln. The hydrogenation of CO was used as the model reaction. The process depends on 3 features in the prepn.: the prepn. of the single mol. layer MoS2, the deposition of these as single layers onto high-surface-area Al2O3 or deposition of Al2O3 onto single layers of MoS2 and the deposition of monolayers of Ni onto the single layers of MoS2. With this structure, suitably calcined and reduced to improve the interaction between Mo, Ni, and Al2O3, a very high d. of active sites per unit area was obtained. The most active sites are a form of oxysulfide. The active sites behave differently from Ni supported on Al2O3. The Ni/Mo/Al2O3 compn. yields CO2 as the byproduct of methanation, instead of the H2O obsd. with the Ni/Al2O3 compn., and has a different activation energy. A specific formulation designed to give the max. d. of accessible Ni/Mo/Al2O3 sites shows an activity substantially higher than Ni/Al2O3. The activity of catalysts prepd. by exfoliation is substantially higher than that of those prepd. by pptn. from ammonium heptamolybdate.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL2sXhsVCksrk%253D&md5=b22856197973beda281bfdf798695533
189
Novoselov, K. S.; Jiang, D.; Schedin, F.; Booth, T. J.; Khotkevich, V. V.; Morozov, S. V.; Geim, A. K. Two-Dimensional Atomic Crystals Proc. Natl. Acad. Sci. U. S. A. 2005, 102, 10451– 10453 DOI: 10.1073/pnas.0502848102

Google Scholar

189
Two-dimensional atomic crystals

Novoselov, K. S.; Jiang, D.; Schedin, F.; Booth, T. J.; Khotkevich, V. V.; Morozov, S. V.; Geim, A. K.

Proceedings of the National Academy of Sciences of the United States of America (2005), 102 (30), 10451-10453CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)

The authors report free-standing at. crystals that are strictly 2-dimensional and can be viewed as individual at. planes pulled out of bulk crystals or as unrolled single-wall nanotubes. By using micromech. cleavage, the authors prepd. and studied a variety of 2-dimensional crystals including single layers of boron nitride, graphite, several dichalcogenides, and complex oxides. These atomically thin sheets (essentially gigantic 2-dimensional mols. unprotected from the immediate environment) are stable under ambient conditions, exhibit high crystal quality, and are continuous on a macroscopic scale.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXntVSit7g%253D&md5=1ce9e5f5eb0f7b9abb033d4a690d49c3
190
Coleman, J. N.; Lotya, M.; O’Neill, A.; Bergin, S. D.; King, P. J.; Khan, U.; Young, K.; Gaucher, A.; De, S.; Smith, R. J. Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials Science 2011, 331, 568– 571 DOI: 10.1126/science.1194975

Google Scholar

190
Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials

Coleman, Jonathan N.; Lotya, Mustafa; O'Neill, Arlene; Bergin, Shane D.; King, Paul J.; Khan, Umar; Young, Karen; Gaucher, Alexandre; De, Sukanta; Smith, Ronan J.; Shvets, Igor V.; Arora, Sunil K.; Stanton, George; Kim, Hye-Young; Lee, Kangho; Kim, Gyu Tae; Duesberg, Georg S.; Hallam, Toby; Boland, John J.; Wang, Jing Jing; Donegan, John F.; Grunlan, Jaime C.; Moriarty, Gregory; Shmeliov, Aleksey; Nicholls, Rebecca J.; Perkins, James M.; Grieveson, Eleanor M.; Theuwissen, Koenraad; McComb, David W.; Nellist, Peter D.; Nicolosi, Valeria

Science (Washington, DC, United States) (2011), 331 (6017), 568-571CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy storage. Layered compds. such as MoS2, WS2, MoSe2, MoTe2, TaSe2, NbSe2, NiTe2, BN, and Bi2Te3 can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solns., the authors can prep. hybrid dispersions or composites, which can be cast into films. WS2 and MoS2 effectively reinforce polymers, whereas WS2/carbon nanotube hybrid films have high cond., leading to promising thermoelec. properties.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtlWisLY%253D&md5=7bd4a9da1b4f81f2caa3d1159dd8a5c7
191
Song, S. H.; Kim, B. H.; Choe, D. H.; Kim, J.; Kim, D. C.; Lee, D. J.; Kim, J. M.; Chang, K. J.; Jeon, S. Bandgap Widening of Phase Quilted, 2D MoS2 by Oxidative Intercalation Adv. Mater. 2015, 27, 3152– 3158 DOI: 10.1002/adma.201500649

Google Scholar

191
Bandgap Widening of Phase Quilted, 2D MoS2 by Oxidative Intercalation

Song, Sung Ho; Kim, Bo Hyun; Choe, Duk-Hyun; Kim, Jin; Kim, Dae Chul; Lee, Dong Ju; Kim, Jung Mo; Chang, Kee Joo; Jeon, Seokwoo

Advanced Materials (Weinheim, Germany) (2015), 27 (20), 3152-3158CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

The authors have demonstrated an advance in the bandgap tuning of 2D MoS2 through the control of oxidn. during exfoliation. In the process of making an intercalation compd. of 2D transition metal dichalcogenides (TMDs), it was possible to perform in situ exfoliation and oxidn. of 2D materials with large and thin flake sizes up to 10 000 μm2. The bandgaps of oxidized h-MoSxOy extended into the visible range, suggesting that fine control of oxidn. can be exploited for the bandgap engineering of the 2D TMDs. The underlying mechanism for the bandgap widening of 2D TMDs in this study is the structural phase transition which induces a complex structure composed of quilted phases of h-MoSxOy. The selective oxidn. technique can modulate the bandgap of 2D TMDs in the visible range, providing a new route to bandgap engineering.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmtlKmt78%253D&md5=d40d170af35806e44c5fab5857f0ac3a
192
Zhan, Y.; Liu, Z.; Najmaei, S.; Ajayan, P. M.; Lou, J. Large-Area Vapor-Phase Growth and Characterization of MoS₂ Atomic Layers on a SiO₂ Substrate Small 2012, 8, 966– 971 DOI: 10.1002/smll.201102654

Google Scholar

192
Large-Area Vapor-Phase Growth and Characterization of MoS2 Atomic Layers on a SiO2 Substrate

Zhan, Yongjie; Liu, Zheng; Najmaei, Sina; Ajayan, Pulickel M.; Lou, Jun

Small (2012), 8 (7), 966-971CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)

Monolayer Mo disulfide (MoS2), a two-dimensional crystal with a direct bandgap, is a promising candidate for 2-dimensional nanoelectronic devices complementing graphene. There were recent attempts to produce MoS2 layers via chem. and mech. exfoliation of bulk material. Here the authors demonstrate the large area growth of MoS2 at. layers on SiO2 substrates by a scalable CVD method. The as-prepd. samples can either be readily used for further device fabrication or be easily released from SiO2 and transferred to arbitrary substrates. High resoln. TEM and Raman spectroscopy on the as grown films of MoS2 indicate that the no. of layers range from single layer to a few layers. The authors' results on the direct growth of MoS2 layers on dielec. leading to facile device fabrication possibilities show the expanding set of useful 2-dimensional at. layers, on the heels of graphene, which can be controllably synthesized and manipulated for many applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xitlyht70%253D&md5=a39ddda9639d32ad598a487b777d1968
193
Lee, Y. H.; Zhang, X. Q.; Zhang, W. J.; Chang, M. T.; Lin, C. T.; Chang, K. D.; Yu, Y. C.; Wang, J. T. W.; Chang, C. S.; Li, L. J. Synthesis of Large-Area MoS₂ Atomic Layers with Chemical Vapor Deposition Adv. Mater. 2012, 24, 2320– 2325 DOI: 10.1002/adma.201104798

Google Scholar

193
Synthesis of Large-Area MoS2 Atomic Layers with Chemical Vapor Deposition

Lee, Yi-Hsien; Zhang, Xin-Quan; Zhang, Wenjing; Chang, Mu-Tung; Lin, Cheng-Te; Chang, Kai-Di; Yu, Ya-Chu; Wang, Jacob Tse-Wei; Chang, Chia-Seng; Li, Lain-Jong; Lin, Tsung-Wu

Advanced Materials (Weinheim, Germany) (2012), 24 (17), 2320-2325CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

Large-area MoS2 at. layers are synthesized on SiO2 substrates by chem. vapor deposition using MoO3 and S powders as the reactants. Optical, microscopic and elec. measurements suggest that the synthetic process leads to the growth of MoS2 monolayer. The TEM images verify that the synthesized MoS2 sheets are highly cryst. To check for elec. performance bottom-gated transistors on silica/silicon using photolithog. was fabricated directly on top of the MoS2 sheets. The transfer curve (drain current vs. gate voltage) was computed and field effect mobility was detd. from anal. of the curve.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XkvVKiur8%253D&md5=7b5ca7016ced6baa546a93be5bbe8589
194
Zhang, Y.; Chang, T. R.; Zhou, B.; Cui, Y. T.; Yan, H.; Liu, Z.; Schmitt, F.; Lee, J.; Moore, R.; Chen, Y. Direct Observation of the Transition from Indirect to Direct Bandgap in Atomically Thin Epitaxial MoSe₂ Nat. Nanotechnol. 2013, 9, 111– 115 DOI: 10.1038/nnano.2013.277

Google Scholar

There is no corresponding record for this reference.
195
Liu, Z.; Song, L.; Zhao, S.; Huang, J.; Ma, L.; Zhang, J.; Lou, J.; Ajayan, P. M. Direct Growth of Graphene/Hexagonal Boron Nitride Stacked Layers Nano Lett. 2011, 11, 2032– 2037 DOI: 10.1021/nl200464j

Google Scholar

195
Direct Growth of Graphene/Hexagonal Boron Nitride Stacked Layers

Liu, Zheng; Song, Li; Zhao, Shizhen; Huang, Jiaqi; Ma, Lulu; Zhang, Jiangnan; Lou, Jun; Ajayan, Pulickel M.

Nano Letters (2011), 11 (5), 2032-2037CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Graphene (G) and at. layers of hexagonal boron nitride (h-BN) are complementary 2-dimensional materials, structurally very similar but with vastly different electronic properties. Recent studies indicate that h-BN at. layers would be excellent dielec. layers to complement graphene electronics. Graphene on h-BN has been realized via peeling of layers from bulk material to create G/h-BN stacks. Considering that both these layers can be independently grown via chem. vapor deposition (CVD) of their precursors on metal substrates, it is feasible that these can be sequentially grown on substrates to create the G/h-BN stacked layers useful for applications. Here we demonstrate the direct CVD growth of h-BN on highly oriented pyrolytic graphite and on mech. exfoliated graphene, as well as the large area growth of G/h-BN stacks, consisting of few layers of graphene and h-BN, via a two-step CVD process. The G/h-BN film is uniform and continuous and could be transferred onto different substrates for further characterization and device fabrication.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXks1Glurs%253D&md5=0e9795dd84ec8b8076c8aa4500884437
196
Yu, L.; Lee, Y. H.; Ling, X.; Santos, E. J. G.; Shin, Y. C.; Lin, Y.; Dubey, M.; Kaxiras, E.; Kong, J.; Wang, H. Graphene/MoS₂ Hybrid Technology for Large-Scale Two-Dimensional Electronics Nano Lett. 2014, 14, 3055– 3063 DOI: 10.1021/nl404795z

Google Scholar

196
Graphene/MoS2 Hybrid Technology for Large-Scale Two-Dimensional Electronics

Yu, Lili; Lee, Yi-Hsien; Ling, Xi; Santos, Elton J. G.; Shin, Yong Cheol; Lin, Yuxuan; Dubey, Madan; Kaxiras, Efthimios; Kong, Jing; Wang, Han; Palacios, Tomas

Nano Letters (2014), 14 (6), 3055-3063CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Two-dimensional (2D) materials have generated great interest in the past few years as a new toolbox for electronics. This family of materials includes, among others, metallic graphene, semiconducting transition metal dichalcogenides (such as MoS2), and insulating boron nitride. These materials and their heterostructures offer excellent mech. flexibility, optical transparency, and favorable transport properties for realizing electronic, sensing, and optical systems on arbitrary surfaces. In this paper, we demonstrate a novel technol. for constructing large-scale electronic systems based on graphene/molybdenum disulfide (MoS2) heterostructures grown by chem. vapor deposition. We have fabricated high-performance devices and circuits based on this heterostructure, where MoS2 is used as the transistor channel and graphene as contact electrodes and circuit interconnects. We provide a systematic comparison of the graphene/MoS2 heterojunction contact to more traditional MoS2-metal junctions, as well as a theor. investigation, using d. functional theory, of the origin of the Schottky barrier height. The tunability of the graphene work function with electrostatic doping significantly improves the ohmic contact to MoS2. These high-performance large-scale devices and circuits based on this 2D heterostructure pave the way for practical flexible transparent electronics.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXns1CnsLc%253D&md5=0a11e6ee31fb451ac89156554d5831eb
197
Li, Y.; Wang, H.; Xie, L.; Liang, Y.; Hong, G.; Dai, H. MoS₂ Nanoparticles Grown on Graphene: An Advanced Catalyst for the Hydrogen Evolution Reaction J. Am. Chem. Soc. 2011, 133, 7296– 7299 DOI: 10.1021/ja201269b

Google Scholar

197
MoS2 Nanoparticles Grown on Graphene: An Advanced Catalyst for the Hydrogen Evolution Reaction

Li, Yanguang; Wang, Hailiang; Xie, Liming; Liang, Yongye; Hong, Guosong; Dai, Hongjie

Journal of the American Chemical Society (2011), 133 (19), 7296-7299CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

Advanced materials for electrocatalytic and photoelectrochem. H2O splitting are central to the area of renewable energy. The authors developed a selective solvothermal synthesis of MoS2 nanoparticles on reduced graphene oxide (RGO) sheets suspended in soln. The resulting MoS2/RGO hybrid material possessed nanoscopic few-layer MoS2 structures with an abundance of exposed edges stacked onto graphene, in strong contrast to large aggregated MoS2 particles grown freely in soln. without GO. The MoS2/RGO hybrid exhibited superior electrocatalytic activity in the H evolution reaction (HER) relative to other MoS2 catalysts. A Tafel slope of ∼41 mV/decade was measured for MoS2 catalysts in the HER for the 1st time; this exceeds by far the activity of previous MoS2 catalysts and results from the abundance of catalytic edge sites on the MoS2 nanoparticles and the excellent elec. coupling to the underlying graphene network. The ∼41 mV/decade Tafel slope suggested the Volmer-Heyrovsky mechanism for the MoS2-catalyzed HER, with electrochem. desorption of H as the rate-limiting step.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXltVGgtLo%253D&md5=24655c600b394dc7cea91e459dd70ae7
198
Roy, K.; Padmanabhan, M.; Goswami, S.; Sai, T. P.; Kaushal, S.; Ghosh, A. Optically Active Heterostructures of Graphene and Ultrathin MoS₂ Solid State Commun. 2013, 175, 35– 42 DOI: 10.1016/j.ssc.2013.09.021

Google Scholar

There is no corresponding record for this reference.
199
Roy, K.; Padmanabhan, M.; Goswami, S.; Sai, T. P.; Ramalingam, G.; Raghavan, S.; Ghosh, A. Graphene–MoS₂ Hybrid Structures for Multifunctional Photoresponsive Memory Devices Nat. Nanotechnol. 2013, 8, 826– 830 DOI: 10.1038/nnano.2013.206

Google Scholar

199
Graphene-MoS2 hybrid structures for multifunctional photoresponsive memory devices

Roy, Kallol; Padmanabhan, Medini; Goswami, Srijit; Sai, T. Phanindra; Ramalingam, Gopalakrishnan; Raghavan, Srinivasan; Ghosh, Arindam

Nature Nanotechnology (2013), 8 (11), 826-830CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)

Combining the electronic properties of graphene and MoS2 in hybrid heterostructures offers the possibility to create devices with various functionalities. Electronic logic and memory devices have already been constructed from graphene-MoS2 hybrids, but they do not make use of the photosensitivity of MoS2, which arises from its optical-range bandgap. Graphene-on-MoS2 binary heterostructures display remarkable dual optoelectronic functionality, including highly sensitive photodetection and gate-tunable persistent photocond. The responsivity of the hybrids was found to be nearly 1 × 1010 A W-1 at 130 K and 5 × 108 A W-1 at room temp., making them the most sensitive graphene-based photodetectors. When subjected to time-dependent photoillumination, the hybrids could also function as a rewritable optoelectronic switch or memory, where the persistent state shows almost no relaxation or decay within exptl. timescales, indicating near-perfect charge retention. These effects can be quant. explained by gate-tunable charge exchange between the graphene and MoS2 layers, and may lead to new graphene-based optoelectronic devices that are naturally scalable for large-area applications at room temp.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs1Chsr%252FP&md5=f156654fde1c0af91b6ab3e60b477508
200
Loan, P. T. K.; Zhang, W.; Lin, C. T.; Wei, K. H.; Li, L. J.; Chen, C. H. Graphene/MoS₂ Heterostructures for Ultrasensitive Detection of DNA Hybridisation Adv. Mater. 2014, 26, 4838– 4844 DOI: 10.1002/adma.201401084

Google Scholar

200
Graphene/MoS2 heterostructures for ultrasensitive detection of DNA hybridization

Loan, Phan Thi Kim; Zhang, Wenjing; Lin, Cheng-Te; Wei, Kung-Hwa; Li, Lain-Jong; Chen, Chang-Hsiao

Advanced Materials (Weinheim, Germany) (2014), 26 (28), 4838-4844CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

Hwere we reportthat a hetero-structural stacking film graphene on MoS2 provides an excellent and unltrasensitive platform for the detection of DNA hybridization.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXot1Sit7k%253D&md5=ceb0957b706cabc307dad1d9a2bfa62b
201
Zeng, S.; Hu, S.; Xia, J.; Anderson, T.; Dinh, X. Q.; Meng, X. M.; Coquet, P.; Yong, K. T. Graphene–MoS₂ Hybrid Nanostructures Enhanced Surface Plasmon Resonance Biosensors Sens. Actuators, B 2015, 207, 801– 810 DOI: 10.1016/j.snb.2014.10.124

Google Scholar

201
Graphene-MoS2 hybrid nanostructures enhanced surface plasmon resonance biosensors

Zeng, Shuwen; Hu, Siyi; Xia, Jing; Anderson, Tommy; Dinh, Xuan-Quyen; Meng, Xiang-Min; Coquet, Philippe; Yong, Ken-Tye

Sensors and Actuators, B: Chemical (2015), 207 (Part_A), 801-810CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)

The authors propose a new configuration of surface plasmon resonance (SPR) sensor that is based on graphene-MoS2 hybrid structures for ultrasensitive detection of mols. The proposed system displays a phase-sensitivity enhancement factor of >500-fold when compared to the SPR sensing scheme without the graphene-MoS2 coating or with only graphene coating. The authors' hypothesis is that the monolayer MoS2 has a much higher optical absorption efficiency (∼5%) than that of the graphene layer (∼2.3%). Based on the authors' findings, the electron energy loss of MoS2 layer is comparable to that of graphene and this will allow a successful (∼100%) of light energy transfer to the graphene-MoS2 coated sensing substrate. Such process will lead to a significant enhancement of SPR signals. The authors' simulation shows that a quasi-dark point of the reflected light can be achieved under this condition and this resulted in a steep phase jump at the resonance angle of the authors' newly proposed SPR system. More importantly, phase interrogation detection approach of the graphene-MoS2 hybrid structures-based sensing system is more sensitive than that of using the regularly angular interrogation method and the authors' theor. anal. indicates that 45 nm of Au film thickness and 3 coating layers of MoS2 nanosheet are the optimized parameters needed for the proposed SPR system to achieve the highest detection sensitivity range.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFShtrfP&md5=d2cf09ba6d69b4b5b34f95affb1b604a
202
Meng, J.; Song, H. D.; Li, C. Z.; Jin, Y.; Tang, L.; Liu, D.; Liao, Z. M.; Xiu, F.; Yu, D. P. Lateral Graphene p-n Junctions Formed by Graphene/MoS₂ Hybrid Interface Nanoscale 2015, 7, 11611– 11619 DOI: 10.1039/C5NR02552D

Google Scholar

There is no corresponding record for this reference.
203
Shiva, K.; Matte, H. S. S. R.; Rajendra, H. B.; Bhattacharyya, A. J.; Rao, C. N. R. Employing Synergistic Interactions Between Few-Layer WS₂ and Reduced Graphene Oxide to Improve Lithium Storage, Cyclability and Rate Capability of Li-Ion Batteries Nano Energy 2013, 2, 787– 793 DOI: 10.1016/j.nanoen.2013.02.001

Google Scholar

203
Employing synergistic interactions between few-layer WS2 and reduced graphene oxide to improve lithium storage, cyclability and rate capability of Li-ion batteries

Shiva, Konda; Ramakrishna Matte, H. S. S.; Rajendra, H. B.; Bhattacharyya, Aninda J.; Rao, C. N. R.

Nano Energy (2013), 2 (5), 787-793CODEN: NEANCA; ISSN:2211-2855. (Elsevier Ltd.)

The aim of the contribution is to introduce a high performance anode alternative to graphite for lithium-ion batteries (LiBs). A simple process was employed to synthesize uniform graphene-like few-layer tungsten sulfide (WS2) supported on reduced graphene oxide (RGO) through a hydrothermal synthesis route. The WS2-RGO (80:20 and 70:30) composites exhibited good enhanced electrochem. performance and excellent rate capability performance when used as anode materials for lithium-ion batteries. The specific capacity of the WS2-RGO composite delivered a capacity of 400-450 mAh g-1 after 50 cycles when cycled at a c.d. of 100 mA g-1. At 4000 mA g-1, the composites showed a stable capacity of approx. 180-240 mAh g-1, resp. The noteworthy electrochem. performance of the composite is not additive, rather it is synergistic in the sense that the electrochem. performance is much superior compared to both WS2 and RGO. As the obsd. lithiation/delithiation for WS2-RGO is at a voltage≈1.0 V (≈0.1 V for graphite, Li+/Li), the lithium-ion battery with WS2-RGO is expected to possess high interface stability, safety and management of elec. energy is expected to be more efficient and economic.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXksFarsrk%253D&md5=e84d464952a2bb7859872f0582b00272
204
Roy, T.; Tosun, M.; Kang, J. S.; Sachid, A. B.; Desai, S. B.; Hettick, M.; Hu, C. C.; Javey, A. Field-Effect Transistors Built from All Two-Dimensional Material Components ACS Nano 2014, 8, 6259– 6264 DOI: 10.1021/nn501723y

Google Scholar

204
Field-Effect Transistors Built from All Two-Dimensional Material Components

Roy, Tania; Tosun, Mahmut; Kang, Jeong Seuk; Sachid, Angada B.; Desai, Sujay B.; Hettick, Mark; Hu, Chenming C.; Javey, Ali

ACS Nano (2014), 8 (6), 6259-6264CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

We demonstrate field-effect transistors using heterogeneously stacked two-dimensional materials for all of the components, including the semiconductor, insulator, and metal layers. Specifically, MoS2 is used as the active channel material, hexagonal-BN as the top-gate dielec., and graphene as the source/drain and the top-gate contacts. This transistor exhibits n-type behavior with an ON/OFF current ratio of >106, and an electron mobility of ∼33 cm2/V·s. Uniquely, the mobility does not degrade at high gate voltages, presenting an important advantage over conventional Si transistors where enhanced surface roughness scattering severely reduces carrier mobilities at high gate-fields. A WSe2-MoS2 diode with graphene contacts is also demonstrated. The diode exhibits excellent rectification behavior and a low reverse bias current, suggesting high quality interfaces between the stacked layers. In this work, all interfaces are based on van der Waals bonding, presenting a unique device architecture where cryst., layered materials with atomically uniform thicknesses are stacked on demand, without the lattice parameter constraints. The results demonstrate the promise of using an all-layered material system for future electronic applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXntFOgtL8%253D&md5=259674628a1815dcd889fe8df02527b9
205
Zhang, S.; Zhang, X.; Jiang, G.; Zhu, H.; Guo, S.; Su, D.; Lu, G.; Sun, S. Tuning Nanoparticle Structure and Surface Strain for Catalysis Optimization J. Am. Chem. Soc. 2014, 136, 7734– 7739 DOI: 10.1021/ja5030172

Google Scholar

205
Tuning Nanoparticle Structure and Surface Strain for Catalysis Optimization

Zhang, Sen; Zhang, Xu; Jiang, Guangming; Zhu, Huiyuan; Guo, Shaojun; Su, Dong; Lu, Gang; Sun, Shouheng

Journal of the American Chemical Society (2014), 136 (21), 7734-7739CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

Controlling nanoparticle (NP) surface strain, i.e. compression (or stretch) of surface atoms, is an important approach to tune NP surface chem. and to optimize NP catalysis for chem. reactions. Surface Pt strain in the core/shell FePt/Pt NPs with Pt in 3 at layers can be rationally tuned via core structural transition from cubic solid soln. [denoted as fcc.] structure to tetragonal intermetallic [denoted as face centered tetragonal (fct)] structure. The high activity obsd. from the fct-FePt/Pt NPs for O redn. reaction (ORR) is due to the release of the over-compressed Pt strain by the fct-FePt as suggested by quantum mechanics-mol. mechanics (QM-MM) simulations. The Pt strain effect on ORR can be further optimized when Fe in FePt is partially replaced by Cu. As a result, the fct-FeCuPt/Pt NPs become the most efficient catalyst for ORR and are nearly 10 times more active in specific activity than the com. Pt catalyst. This structure-induced surface strain control opens up a new path to tune and optimize NP catalysis for ORR and many other chem. reactions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXns1Ciu7s%253D&md5=62b0f6656accee9218e9f74971a01fda
206
Liu, X.; Sui, Y. H.; Meng, C. G.; Han, Y. Tuning the Reactivity of Ru Nanoparticles by Defect Engineering of the Reduced Graphene Oxide Support RSC Adv. 2014, 4, 22230– 22240 DOI: 10.1039/C4RA02900C

Google Scholar

206
Tuning the reactivity of Ru nanoparticles by defect engineering of the reduced graphene oxide support

Liu, Xin; Sui, Yanhui; Meng, Changgong; Han, Yu

RSC Advances (2014), 4 (42), 22230-22240CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

We systematically investigated the electronic structure of Ru nanoparticles supported on various local structures on reduced graphene oxide (rGO) by first-principles-based calcns. We showed that Ru nanoparticles prefer to nucleate at these localized defect structures on rGO, which act as strong trapping sites for Ru nanoparticles and inhibit their aggregation. The binding of Ru nanoparticles to rGO, which is dependent on these local defect structures and correlates with the interfacial charge transfer, dets. the electronic structure of the composites. Further study reveals that the performance of these composites against oxygen adsorption changes proportionally with the shift of the d-band center of the nanoparticles. The correlation between the defect structures on rGO and the reactivity of the composites suggests that controlled modification of the graphenic support by defect engineering would be an efficient way to fabricate new transition metal/rGO composites with high stability and desired reactivity.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXovVegtb4%253D&md5=d80baf8c39f834debb4afb4e404f537d
207
Duan, J.; Chen, S.; Dai, S.; Qiao, S. Z. Shape Control of Mn₃O₄ Nanoparticles on Nitrogen-Doped Graphene for Enhanced Oxygen Reduction Activity Adv. Funct. Mater. 2014, 24, 2072– 2078 DOI: 10.1002/adfm.201302940

Google Scholar

207
Shape Control of Mn3O4 Nanoparticles on Nitrogen-Doped Graphene for Enhanced Oxygen Reduction Activity

Duan, Jingjing; Chen, Sheng; Dai, Sheng; Qiao, Shi Zhang

Advanced Functional Materials (2014), 24 (14), 2072-2078CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

Three kinds of Mn3O4 nanoparticles with different shapes (spheres, cubes, and ellipsoids) are selectively grown on N-doped graphene sheets through a 2-step liq.-phase procedure. These nonprecious hybrid materials display an excellent ORR activity and good durability. The mesoporous microstructure, N doping, and strong bonding between metal species and doped graphene facilitate the ORR catalytic process. Among these 3 kinds of Mn3O4 particles, the ellipsoidal particles on N-doped graphene exhibit the highest ORR activity with a more pos. onset-potential of -0.13 V (close to that of Pt/C, -0.09 V) and a higher kinetic limiting c.d. (JK) of 11.69 mA cm-2 at -0.60 V. The ORR performance of hybrid materials can be correlated to the shape of Mn3O4 nanocrystals, and specifically to the exposed cryst. facets assocd. with a given shape. The shape dependence of Mn3O4 nanoparticles integrated with N-doped graphene on the ORR performance, reported here for the 1st time, may advance the development of fuel cells and metal-air batteries.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvVOhtrvN&md5=a61bcd6ff8df5b81b0dd912d78dee0ab
208
Li, W.; Wang, F.; Feng, S.; Wang, J.; Sun, Z.; Li, B.; Li, Y.; Yang, J.; Elzatahry, A. A.; Xia, Y. Sol-Gel Design Strategy for Ultradispersed TiO₂ Nanoparticles on Graphene for High-Performance Lithium Ion Batteries J. Am. Chem. Soc. 2013, 135, 18300– 18303 DOI: 10.1021/ja4100723

Google Scholar

208
Sol-gel design strategy for ultradispersed TiO2 nanoparticles on graphene for high-performance lithium ion batteries

Li, Wei; Wang, Fei; Feng, Shanshan; Wang, Jinxiu; Sun, Zhenkun; Li, Bin; Li, Yuhui; Yang, Jianping; Elzatahry, Ahmed A.; Xia, Yongyao; Zhao, Dongyuan

Journal of the American Chemical Society (2013), 135 (49), 18300-18303CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

The rational design and controllable synthesis of strongly coupled inorg./graphene hybrids represents a long-standing challenge for developing advanced catalysts and energy-storage materials. Here, we report a simple sol-gel method toward creating ultradispersed TiO2 nanoparticles on graphene with an unprecedented degree of control based on the precise sepn. and manipulation of nanoparticles nucleated, grown, anchored, and crystd. and the redn. of graphene oxide (GO). The hybrid materials show ultradispersed anatase nanoparticles (∼5 nm), ultrathin thickness (≤3 layers), and a high surface area of ∼229 m2/g and exhibit a high specific capacity of ∼94 mA h g-1 at ∼59 C, which is twice as that of mech. mixed composites (∼41 mA h g-1), demonstrating the potential of strongly synergistic coupling effects for advanced functional systems.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvVShsLzK&md5=e30dd74a1700a53aea1ce1153fceec9b
209
Guo, S.; Zhang, S.; Wu, L.; Sun, S. Co/CoO Nanoparticles Assembled on Graphene for Electrochemical Reduction of Oxygen Angew. Chem., Int. Ed. 2012, 51, 11770– 11773 DOI: 10.1002/anie.201206152

Google Scholar

209
Co/CoO Nanoparticles Assembled on Graphene for Electrochemical Reduction of Oxygen

Guo, Shaojun; Zhang, Sen; Wu, Liheng; Sun, Shouheng

Angewandte Chemie, International Edition (2012), 51 (47), 11770-11773CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

Authors reported that monodisperse Co/CoO nanoparticles could be presynthesized and deposited on a G surface by the soln.-phase self-assembly method. The formed structure is a high-performance electrocatalyst for the ORR in potassium hydroxide soln. The particle size and interfacial interactions affect the electrocatalytic properties.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsFans7vP&md5=3ed756b9eea505ff4ee0dcf4b62dade9
210
Duy-Thach, P.; Chung, G. S. A Novel Pd Nanocube-Graphene Hybrid for Hydrogen Detection Sens. Actuators, B 2014, 199, 354– 360 DOI: 10.1016/j.snb.2014.04.013

Google Scholar

There is no corresponding record for this reference.
211
Jabeen, H.; Kemp, K. C.; Chandra, V. Synthesis of Nano Zerovalent Iron Nanoparticles - Graphene Composite for the Treatment of Lead Contaminated Water J. Environ. Manage. 2013, 130, 429– 435 DOI: 10.1016/j.jenvman.2013.08.022

Google Scholar

211
Synthesis of nano zerovalent iron nanoparticles - Graphene composite for the treatment of lead contaminated water

Jabeen, Humera; Kemp, K. Christian; Chandra, Vimlesh

Journal of Environmental Management (2013), 130 (), 429-435CODEN: JEVMAW; ISSN:0301-4797. (Elsevier Ltd.)

A Nano zerovalent iron nanoparticles graphene composite (G-nZVI) was prepd. via a sodium borohydride redn. of graphene oxide and iron chloride under an argon atm. Powder X-ray diffraction patterns showed the formation of the magnetic graphene/nanoscale-zerovalent-iron (G-nZVI) composites and bare nanoscale-zerovalent-iron (nZVI) particles. TEM anal. shows the formation of ∼10 nm particles. Adsorption expts. show a max. Pb(II) adsorption capacity for the G-nZVI composite with 6 wt% graphene oxide loading. Addnl. the effects of pH, temp., contact time, ionic strength and initial metal ion concn. on Pb(II) ion removal were studied. XPS anal. after adsorption results confirmed the composite's ability to adsorb and immobilize lead more efficiently in its zerovalent and bivalent forms, as compared to bare iron nanoparticles. The adsorption of Pb(II) ions fit a pseudo-second-order kinetic model, and adsorption isotherms can be described using the Freundlich equations. G-nZVI shows great potential as an efficient adsorbent for lead immobilization from water, as it exhibits stability, reducing power, a large surface area, and magnetic sepn.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsl2jsLnO&md5=789330e77a7e59880b0fe647427d1d63
212
Seema, H.; Kemp, K. C.; Chandra, V.; Kim, K. S. Graphene-SnO₂ Composites for Highly Efficient Photocatalytic Degradation of Methylene Blue under Sunlight Nanotechnology 2012, 23, 355705 DOI: 10.1088/0957-4484/23/35/355705

Google Scholar

There is no corresponding record for this reference.
213
Jin, S.; Chen, M.; Dong, H.; He, B.; Lu, H.; Su, L.; Dai, W.; Zhang, Q.; Zhang, X. Stable Silver Nanoclusters Electrochemically Deposited on Nitrogen-Doped Graphene as Efficient Electrocatalyst for Oxygen Reduction Reaction J. Power Sources 2015, 274, 1173– 1179 DOI: 10.1016/j.jpowsour.2014.10.098

Google Scholar

213
Stable silver nanoclusters electrochemically deposited on nitrogen-doped graphene as efficient electrocatalyst for oxygen reduction reaction

Jin, Shi; Chen, Man; Dong, Haifeng; He, Bingyu; Lu, Huiting; Su, Lei; Dai, Wenhao; Zhang, Qiaochu; Zhang, Xueji

Journal of Power Sources (2015), 274 (), 1173-1179CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)

Metal nanoclusters exhibit unusually high catalytic activity toward oxygen redn. reaction (ORR) due to their small size and unique electronic structures. However, controllable synthesis of stable metal nanoclusters is a challenge, and the durability of metal clusters suffers from the deficiency of dissoln., aggregation, and sintering during catalysis reactions. Herein, silver nanoclusters (AgNCs) (diam. < 2 nm) were controllably electrochem. reduced on nitrogen-doped graphene (NG) using effective single-stranded oligonucleotide sequences (ssDNA) as the performed template in absence of any other reluctant. The ssDNA is significant for providing AgNCs with growth template and anchoring the cluster on graphene surface. The strong interaction between the AgNCs, ssDNA and NG renders the as-synthesized AgNCs/NG composite with high-performance onset potential, half-wave potential and mass activity for ORR approaching to com. Pt/C catalyst, and remarkably superior ORR performance than NG and Ag nanoparticle/NG. Importantly, the AgNCs/NG composite shows excellent methanol tolerance and accelerated electrochem. stability (8000 cycles), which is vital in high performance fuel cells, batteries, and nanodevices.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVGhsLfP&md5=2fee5cacd5faca8fb85b0f1139ab407c
214
Hui, K. S.; Hui, K. N.; Dinh, D. A.; Tsang, C. H.; Cho, Y. R.; Zhou, W.; Hong, X.; Chun, H. H. Green Synthesis of Dimension-Controlled Silver Nanoparticle-Graphene Oxide with in Situ Ultrasonication Acta Mater. 2014, 64, 326– 332 DOI: 10.1016/j.actamat.2013.10.045

Google Scholar

214
Green synthesis of dimension-controlled silver nanoparticle-graphene oxide with in situ ultrasonication

Hui, K. S.; Hui, K. N.; Dinh, D. A.; Tsang, C. H.; Cho, Y. R.; Zhou, Wei; Hong, Xiaoting; Chun, Ho-Hwan

Acta Materialia (2014), 64 (), 326-332CODEN: ACMAFD; ISSN:1359-6454. (Elsevier Ltd.)

A green chem. approach to control the dimensions of Ag nanoparticle-decorated graphene oxide (AgNP-GO) composites was proposed by in situ ultrasonication of a mixt. of AgNO3 and GO soln. with the assistance of vitamin C acting as an environmentally friendly reducing agent at room temp. The AgNP-GO composites were characterized by x-ray diffraction, TEM, energy-dispersive spectroscopy, FTIR, Raman spectra, and UV-visible absorption spectra. Ag nanoparticles with an av. diam. of ≈15 nm were uniformly dispersed on the surface of GO nanosheets by in situ ultrasonication of 1 min with vitamin C. Increasing the ultrasonication times resulted in Ag nanoparticles with tunable dimensions ranging from 15 to 55 nm being formed on the surface of GO nanosheets. The amt. of AgNO3 and the ultrasonication time play a key role in the control of the dimension of Ag nanoparticles on GO, and a formation mechanism of the as-prepd. AgNP-GO composites is proposed. This study provides a guide to controlling the dimensions of AgNP-GO composites, which may hold promise as advanced materials for various anal. applications such as catalysis, sensors, and microchips.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvVWgu7nI&md5=c4d0039fdc9a7d2082134d702e5e338c
215
Moussa, S.; Siamaki, A. R.; Gupton, B. F.; El-Shall, M. S. Pd-Partially Reduced Graphene Oxide Catalysts (Pd/PRGO): Laser Synthesis of Pd Nanoparticles Supported on PRGO Nanosheets for Carbon-Carbon Cross Coupling Reactions ACS Catal. 2012, 2, 145– 154 DOI: 10.1021/cs200497e

Google Scholar

215
Pd-Partially Reduced Graphene Oxide Catalysts (Pd/PRGO): Laser Synthesis of Pd Nanoparticles Supported on PRGO Nanosheets for Carbon-Carbon Cross Coupling Reactions

Moussa, Sherif; Siamaki, Ali R.; Gupton, B. Frank; El-Shall, M. Samy

ACS Catalysis (2012), 2 (1), 145-154CODEN: ACCACS; ISSN:2155-5435. (American Chemical Society)

This paper reports the development of a new family of highly active Pd nanoparticle catalysts supported on partially reduced graphene oxide nanosheets for carbon-carbon cross-coupling reactions. We report, for the first time, the synthesis of Pd nanoparticle catalysts supported on partially reduced graphene nanosheets (Pd/PRGO) by pulsed laser irradn. of aq. solns. of graphene oxide and palladium ions without the use of chem. reducing or capping agents. The redox reactions initiated by the photoexcitation of GO using two 532 nm photons in different reducing environments of appropriate protic solvents (water, methanol, and ethanol) result in the formation of Pd nanoparticles with different sizes supported on the PRGO nanosheets. The laser irradn. process leads to the formation of multiple defect sites on the surface of the PRGO nanosheets which provide an excellent environment for anchoring the Pd nanoparticles, thus impeding the particles' migration and increasing the catalyst-support interaction. This consequently contributes to the enhanced catalytic performance and recyclability of the catalyst. The Pd/PRGO catalyst generated in water demonstrates excellent catalytic activity for Suzuki, Heck, and Sonogashira cross coupling reactions, with good recyclability for Suzuki coupling with a turn over no. (TON) of 7800 and a remarkable turnover frequency (TOF) of 230,000 h-1 at 120 °C under microwave heating. The results indicate that the defect sites generated on the PRGO nanosheets by the laser photochem. process play a major role in imparting the exceptional catalytic properties to these catalysts.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhsFKkt7zI&md5=9bbf0f80c7958628d06e2f46b0ed9a73
216
Liu, G.; Wang, Y.; Pu, X.; Jiang, Y.; Cheng, L.; Jiao, Z. One-Step Synthesis of High Conductivity Silver Nanoparticle-Reduced Graphene Oxide Composite Films by Electron Beam Irradiation Appl. Surf. Sci. 2015, 349, 570– 575 DOI: 10.1016/j.apsusc.2015.05.044

Google Scholar

There is no corresponding record for this reference.
217
Haider, M. S.; Badejo, A. C.; Shao, G. N.; Imran, S. M.; Abbas, N.; Chai, Y. G.; Hussain, M.; Kim, H. T. Sequential Repetitive Chemical Reduction Technique to Study Size-Property Relationships of Graphene Attached Ag Nanoparticle Solid State Sci. 2015, 44, 1– 9 DOI: 10.1016/j.solidstatesciences.2015.03.024

Google Scholar

217
Sequential repetitive chemical reduction technique to study size-property relationships of graphene attached Ag nanoparticle

Haider, M. Salman; Badejo, Abimbola Comfort; Shao, Godlisten N.; Imran, S. M.; Abbas, Nadir; Chai, Young Gyu; Hussain, Manwar; Kim, Hee Taik

Solid State Sciences (2015), 44 (), 1-9CODEN: SSSCFJ; ISSN:1293-2558. (Elsevier Masson SAS)

The present study demonstrates a novel, systematic and application route synthesis approach to develop size-property relationship and control the growth of silver nanoparticles (AgNPs) embedded on reduced graphene oxide (rGO). A sequential repetitive chem. redn. technique to observe the growth of silver nanoparticles (AgNPs) attached to rGO, was performed on a single soln. of graphene oxide (GO) and silver nitrate soln. (7 runs, R1-R7) in order to manipulate the growth and size of the AgNPs. The phys.-chem. properties of the samples were examd. by RAMAN, XPS, XRD, SEM-EDAX, and HRTEM analyses. It was confirmed that AgNPs with diam. varying from 4 nm in first run (R1) to 50 nm in seventh run (R7) can be obtained using this technique. A major correlation between particle size and activities was also obsd. Antibacterial activities of the samples were carried out to investigate the disinfection performance of the samples on the Gram neg. bacteria (Escherichia coli). It was suggested that the sample obtained in the third run (R3) exhibited the highest antibacterial activity as compared to other samples, toward disinfection of bacteria due to its superior properties. This study provides a unique and novel application route to synthesize and control size of AgNPs embedded on graphene for various applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXls1Gmurc%253D&md5=96a288ae685d5da229b92688e75c569f
218
Shi, J.; Zhou, X.; Liu, Y.; Su, Q.; Zhang, J.; Du, G. Sonochemical Synthesis of CuS/Reduced Graphene Oxide Nanocomposites with Enhanced Absorption and Photocatalytic Performance Mater. Lett. 2014, 126, 220– 223 DOI: 10.1016/j.matlet.2014.04.051

Google Scholar

218
Sonochemical synthesis of CuS/reduced graphene oxide nanocomposites with enhanced absorption and photocatalytic performance

Shi, Jingjing; Zhou, Xiaoyan; Liu, Ya; Su, Qingmei; Zhang, Jun; Du, Gaohui

Materials Letters (2014), 126 (), 220-223CODEN: MLETDJ; ISSN:0167-577X. (Elsevier B.V.)

The CuS nanoparticle-decorated reduced graphene oxide (CuS/rGO) composites have been successfully prepd. via a sonochem. method. X-ray diffraction and electron microscopy observations confirm that CuS nanoparticles of 10-25 nm are well distributed on the rGO nanosheets. UV-visible spectroscopy reveals the CuS/rGO nanocomposites show a strong and broad light absorption. Photocatalytic performance of the CuS/rGO nanocomposites is evaluated by measuring the decompn. of methylene blue soln. under natural light. The exptl. results reveal that the as-prepd. nanocomposites show remarkably enhanced photocatalytic activity compared with pure CuS. This can be attributed to the enhanced light adsorption, strong dyestuff absorption, and efficient charge transport after the introduction of rGO.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXotFGlur8%253D&md5=0f87d203145966ae01561618165c3d68
219
Thangaraju, D.; Karthikeyan, R.; Prakash, N.; Babuc, S. M.; Hayakawa, Y. Growth and Optical Properties of Cu₂ZnSnS₄ Decorated Reduced Graphene Oxide Nanocomposites Dalton Trans. 2015, 44, 15031– 15041 DOI: 10.1039/C5DT01542A

Google Scholar

There is no corresponding record for this reference.
220
Bera, R.; Kundu, S.; Patra, A. 2D Hybrid Nanostructure of Reduced Graphene Oxide-CdS Nanosheet for Enhanced Photocatalysis ACS Appl. Mater. Interfaces 2015, 7, 13251– 13259 DOI: 10.1021/acsami.5b03800

Google Scholar

220
2D Hybrid Nanostructure of Reduced Graphene Oxide-CdS Nanosheet for Enhanced Photocatalysis

Bera, Rajesh; Kundu, Simanta; Patra, Amitava

ACS Applied Materials & Interfaces (2015), 7 (24), 13251-13259CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

Graphene-based hybrid nanostructures have recently emerged as a new class of functional materials for light-energy conversion and storage. Here, we have synthesized reduced graphene oxide (RGO)-semiconductor composites to improve the efficiency of photocatalysis. Zero-dimensional CdS nanoparticles (0D), one-dimensional CdS nanorods (1D), and two-dimensional CdS nanosheets (2D) are grafted on the RGO sheet (2D) by a surface modification method using 4-aminothiophenol (4-ATP). Structural anal. confirms the attachment of CdS nanocrystals with RGO, and the strong electronic interaction is found in the case of a CdS nanosheet and RGO, which has an influence on photocatalytic properties. The degrdn. of dye under visible light varies with changing the dimension of nanocrystals, and the catalytic activity of the CdS NS/RGO composite is ∼4 times higher than that of CdS nanoparticle/RGO and 3.4 times higher than that of CdS nanorod/RGO composite samples. The catalytic activity of the CdS nanosheet/RGO composite is also found to be ∼2.5 times than that of pure CdS nanosheet samples. The unique 2D-2D nanoarchitecture would be effective to harvest photons from solar light and transport electrons to reaction sites with respect to other 0D-2D and 1D-2D hybrid systems. This observation can be extended to other graphene-based inorg. semiconductor composites, which can provide a valuable opportunity to explore novel hybrid materials with superior visible-light-induced catalytic activity.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXpsFarsrY%253D&md5=9dc6dbd82ffae9d7621e63fa4c374bcc
221
Wang, Z.; Shi, G.; Zhang, F.; Xia, J.; Gui, R.; Yang, M.; Bi, S.; Xia, L.; Li, Y.; Xia, L. Amphoteric Surfactant Promoted Three-Dimensional Assembly of Graphene Micro/Nanoclusters to Accomodate Pt Nanoparticles for Methanol Oxidation Electrochim. Acta 2015, 160, 288– 295 DOI: 10.1016/j.electacta.2015.02.009

Google Scholar

221
Amphoteric surfactant promoted three-dimensional assembly of graphene micro/nanoclusters to accommodate Pt nanoparticles for methanol oxidation

Wang, Zonghua; Shi, Guoyu; Zhang, Feifei; Xia, Jianfei; Gui, Rijun; Yang, Min; Bi, Sai; Xia, Lin; Li, Yanhui; Xia, Linhua; Xia, Yanzhi

Electrochimica Acta (2015), 160 (), 288-295CODEN: ELCAAV; ISSN:0013-4686. (Elsevier Ltd.)

An intelligent amphoteric surfactant (Na lauryl aminopropionate) was introduced to the construction of 3-dimensional graphene micro/nanoclusters, which was used to the synthesis of Pt nanoparticles to obtain the Pt/3D graphene micro/nanocomposite. Owing to the unique pH induced charge transition and micellar arranging property of the amphoteric surfactant, a higher-order assembly of 3-dimensional porous graphene-based architectures from stacked graphene oxide layers can be readily achieved. More importantly, the as-made catalyst Pt/3D graphene exhibits unprecedented activity, excellent CO tolerance and good stability towards MeOH oxidn. which can be attributed to the large surface area, efficient mass transport within the composite and the uniform distribution of small Pt NPs. These outstanding electrochem. properties make Pt/3D graphene a promising catalyst applied in direct MeOH fuel cells.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitVGiur4%253D&md5=d2efcae6613f02e557a90656b19d7fcf
222
Atar, N.; Eren, T.; Yola, M. L.; Gerengi, H.; Wang, S. Fe@Ag Nanoparticles Decorated Reduced Graphene Oxide as Ultrahigh Capacity Anode Material for Lithium-Ion Battery Ionics 2015, 21, 3185– 3192 DOI: 10.1007/s11581-015-1520-1

Google Scholar

222
Fe@Ag nanoparticles decorated reduced graphene oxide as ultrahigh capacity anode material for lithium-ion battery

Atar, Necip; Eren, Tanju; Yola, Mehmet Lutfi; Gerengi, Husnu; Wang, Shaobin

Ionics (2015), 21 (12), 3185-3192CODEN: IONIFA; ISSN:0947-7047. (Springer)

In the present study, we report the synthesis of Fe@Ag nanoparticles/2-aminoethanethiol functionalized reduced graphene oxide (rGO) composite (Fe@AuNPs-AETrGO) and its application as an improved anode material for lithium-ion batteries (LIBs). The structure of the Fe@AgNPs-AETrGO composite was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), SEM (SEM), and XPS. The electrochem. performance was investigated at different charge/discharge current rates by using CR2032 coin-type cells and cyclic voltammetry (CV). It was found that the spherical Fe@AuNPs were highly dispersed on the rGO sheets. Moreover, the Fe@AuNPs-AETrGO composite showed high specific gravimetric capacity of about 1500 mAh g-1 and long-term cycle stability.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXht1Grtb3L&md5=8caea25359166585cbdb2d6864526523
223
Fonsaca, J. E. S.; Elias, A. L.; Domingues, S. H.; Oliveira, M. M.; Endo, M.; Orth, E. S.; Terrones, M.; Zarbin, A. J. G. Graphene Nanoribbons Inducing Cube-Shaped Ag Nanoparticle Assemblies Carbon 2015, 93, 800– 811 DOI: 10.1016/j.carbon.2015.05.098

Google Scholar

There is no corresponding record for this reference.
224
Toth, P. S.; Velický, M.; Ramasse, Q. M.; Kepaptsoglou, D. M.; Dryfe, R. A. W. Symmetric and Asymmetric Decoration of Graphene: Bimetal-Graphene Sandwiches Adv. Funct. Mater. 2015, 25, 2899– 2909 DOI: 10.1002/adfm.201500277

Google Scholar

224
Symmetric and Asymmetric Decoration of Graphene: Bimetal-Graphene Sandwiches

Toth, Peter S.; Velicky, Matej; Ramasse, Quentin M.; Kepaptsoglou, Desponia M.; Dryfe, Robert A. W.

Advanced Functional Materials (2015), 25 (19), 2899-2909CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

Low-cost, soln. chem.-based, two-step functionalization of an individual, free-standing, chem. vapor-deposited graphene monolayer is reported, with noble metal (Au, Pt, Pd) nanoparticles to build up two-side decorated graphene-based metal nanoclusters. Either the same metal (sym. decoration) or different metals (asym. decoration) are used for the prepn. of bimetal graphene sandwiches, which are adsorbed at the liq./liq. (org./water) interface. The successful fabrication of such dual-decorated graphene-based metal nanocomposites is confirmed using various microscopic techniques (scanning electron and at. force microscopies) and several spectroscopic methods (x-ray photoelectron, energy dispersive x-ray, mapping mode Raman spectra, and electron energy loss spectra). Taken together, it is inferred from these techniques that the location of deposited metal nanoparticles is on opposite sides of the graphene.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsVOit7c%253D&md5=3a9f3175969545019f83e127797785b0
225
Xiao, F.-X.; Miao, J.; Liu, B. Layer-by-Layer Self-Assembly of CdS Quantum Dots/Graphene Nanosheets Hybrid Films for Photoelectrochemical and Photocatalytic Applications J. Am. Chem. Soc. 2014, 136, 1559– 1569 DOI: 10.1021/ja411651e

Google Scholar

225
Layer-by-Layer Self-Assembly of CdS Quantum Dots/Graphene Nanosheets Hybrid Films for Photoelectrochemical and Photocatalytic Applications

Xiao, Fang-Xing; Miao, Jianwei; Liu, Bin

Journal of the American Chemical Society (2014), 136 (4), 1559-1569CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

In recent years, increasing interest has been devoted to synthesizing graphene-semiconductor nanocomposites as efficient photocatalysts for extensive applications. Unfortunately, it is still challenging to make uniform graphene-semiconductor composite films with controllable film thickness and architecture, which are of paramount importance to meet the application requirements. In this work, stable aq. dispersion of polymer-modified graphene nanosheets (GNs) was prepd. via in situ redn. of exfoliated graphite oxide in the presence of cationic poly-(allylamine hydrochloride) (PAH). The resultant water-sol. PAH-modified GNs (GNs-PAH) in conjunction with tailor-made neg. charged CdS quantum dots (QDs) were utilized as nanobuilding blocks for sequential layer-by-layer (LbL) self-assembly of well-defined GNs-CdS QDs hybrid films, in which CdS QDs overspread evenly on the two-dimensional (2D) GNs. It was found that the alternating GNs-CdS QDs multilayered films showed significantly enhanced photoelectrochem. and photocatalytic activities under visible light irradn. as compared to pure CdS QDs and GNs films. The enhancement was attributed to the judicious integration of CdS QDs with GNs in an alternating manner, which maximizes the 2D structural advantage of GNs in GNs-CdS QDs composite films. In addn., photocatalytic and photoelectrochem. mechanisms of the GNs-CdS QDs multilayered films were also discussed. It is anticipated that our work may open new directions for the fabrication of uniform semiconductor/GNs hybrid films for a wide range of applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjtFagtA%253D%253D&md5=a348c2afb6f8240fd26a58f7721183a4
226
Zhou, R.; Qiao, S. Z. Silver/Nitrogen-Doped Graphene Interaction and Its Effect on Electrocatalytic Oxygen Reduction Chem. Mater. 2014, 26, 5868– 5873 DOI: 10.1021/cm502260m

Google Scholar

226
Silver/Nitrogen-Doped Graphene Interaction and Its Effect on Electrocatalytic Oxygen Reduction

Zhou, Ruifeng; Qiao, Shi Zhang

Chemistry of Materials (2014), 26 (20), 5868-5873CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)

Three types of silver/reduced graphene oxide (Ag/rGO) nanocomposites (one doped with nitrogen and another two without) are synthesized to investigate their at. structures and the oxygen redn. reaction (ORR) performance with them as the electrocatalysts. For the first time, the bonding interaction between Ag and N in N doped rGO (N-rGO) is confirmed by both high resoln. XPS and surface enhanced Raman spectroscopy (SERS). The Ag/N-rGO shows excellent ORR performance, including very high onset potential and c.d., which outperforms those Ag/rGOs without N doping. Detailed electrochem. anal. shows that the ORR mechanism on Ag/N-rGO is different from both Ag and N-rGO, and its excellent performance is caused by the Ag-N bonding which alters the electronic structure of N-rGO.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1Cit7fI&md5=accdbce9511d7215eabc1498527f5847
227
Kemp, K. C.; Vimlesh, C.; Muhammad, S.; Kim, K. S. Reversible CO₂ Adsorption by an Activated Nitrogen Doped Graphene/Polyaniline Material Nanotechnology 2013, 24, 235703 DOI: 10.1088/0957-4484/24/23/235703

Google Scholar

227
Reversible CO2 adsorption by an activated nitrogen doped graphene/polyaniline material

Kemp, K. Christian; Chandra, Vimlesh; Saleh, Muhammad; Kim, Kwang S.

Nanotechnology (2013), 24 (23), 235703, 8 pp.CODEN: NNOTER; ISSN:1361-6528. (IOP Publishing Ltd.)

For effective adsorption of carbon dioxide (CO2), we investigate a porous N functionalized graphene adsorbent produced by the chem. activation of a reduced graphene oxide/polyaniline composite. The N-doped graphene composite is microporous with a max. BET surface area of 1336 m2 g-1. It shows a highly reversible max. CO2 storage capacity of 2.7 mmol g-1 at 298 K and 1 atm (5.8 mmol g-1 at 273 K and 1 atm). The N-doped graphene shows good stability during recycling with only an initial decrease of 10% (3-2.7 mmol g-1) in adsorption capacity before attaining a cycling equil. The adsorbance capacity is correlated with N content × pore vol. or N content × surface area. Given that there is no proper correlation parameter, these factors can be used to increase the CO2 adsorption capacity of N-doped graphene materials for practical utility. The as synthesized material also displays selectivity towards CO2 adsorption compared to H2, N2 Ar or CH4. The as formed material shows that graphene can be uniformly N-doped using the presented synthetic method.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht1Gisr%252FL&md5=f1761150aeb45731c638bdc7b755bf03
228
Park, S.; Hu, Y.; Hwang, J. O.; Lee, E.-S.; Casabianca, L. B.; Cai, W.; Potts, J. R.; Ha, H.-W.; Chen, S.; Oh, J. Chemical Structures of Hydrazine-Treated Graphene Oxide and Generation of Aromatic Nitrogen Doping Nat. Commun. 2012, 3, 638 DOI: 10.1038/ncomms1643

Google Scholar

228
Chemical structures of hydrazine-treated graphene oxide and generation of aromatic nitrogen doping

Park Sungjin; Hu Yichen; Hwang Jin Ok; Lee Eui-Sup; Casabianca Leah B; Cai Weiwei; Potts Jeffrey R; Ha Hyung-Wook; Chen Shanshan; Oh Junghoon; Kim Sang Ouk; Kim Yong-Hyun; Ishii Yoshitaka; Ruoff Rodney S

Nature communications (2012), 3 (), 638 ISSN:.

Chemically modified graphene platelets, produced via graphene oxide, show great promise in a variety of applications due to their electrical, thermal, barrier and mechanical properties. Understanding the chemical structures of chemically modified graphene platelets will aid in the understanding of their physical properties and facilitate development of chemically modified graphene platelet chemistry. Here we use (13)C and (15)N solid-state nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy to study the chemical structure of (15)N-labelled hydrazine-treated (13)C-labelled graphite oxide and unlabelled hydrazine-treated graphene oxide, respectively. These experiments suggest that hydrazine treatment of graphene oxide causes insertion of an aromatic N(2) moiety in a five-membered ring at the platelet edges and also restores graphitic networks on the basal planes. Furthermore, density-functional theory calculations support the formation of such N(2) structures at the edges and help to elucidate the influence of the aromatic N(2) moieties on the electronic structure of chemically modified graphene platelets.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC387otVemug%253D%253D&md5=0538cb797f9e8fcea2034952458aab4f
229
Marquardt, D.; Beckert, F.; Pennetreau, F.; Tölle, F.; Mülhaupt, R.; Riant, O.; Hermans, S.; Barthel, J.; Janiak, C. Hybrid Materials of Platinum Nanoparticles and Thiol-Functionalized Graphene Derivatives Carbon 2014, 66, 285– 294 DOI: 10.1016/j.carbon.2013.09.002

Google Scholar

There is no corresponding record for this reference.
230
Cui, L.; Wu, J.; Ju, H. Synthesis of Bismuth-Nanoparticle-Enriched Nanoporous Carbon on Graphene for Efficient Electrochemical Analysis of Heavy-Metal Ions Chem. - Eur. J. 2015, 21, 11525– 11530 DOI: 10.1002/chem.201500512

Google Scholar

230
Synthesis of Bismuth-Nanoparticle-Enriched Nanoporous Carbon on Graphene for Efficient Electrochemical Analysis of Heavy-Metal Ions

Cui, Lin; Wu, Jie; Ju, Huangxian

Chemistry - A European Journal (2015), 21 (32), 11525-11530CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)

A BiNPs@NPCGS nanocomposite was designed for highly efficient detection of multiple heavy-metal ions by in situ synthesis of bismuth-nanoparticle (BiNP)-enriched nanoporous carbon (NPS) on graphene sheet (GS). The NPCGS was prepd. by pyrolysis of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals deposited on graphene oxide and displayed a high surface area of 1251 m2 g-1 and a pore size of 3.4 nm. BiNPs were deposited on NPCGS in situ by chem. redn. of Bi3+ with NaBH4. Due to the restrictive effect of the pore/surface structure of NPCGS, the BiNPs were uniform and well dispersed on the NPCGS. The BiNPs@NPCGS showed good cond. and high effective area, and the presence of BiNPs allowed it to act as an efficient material for anodic-stripping voltammetric detection of heavy-metal ions. Under optimized conditions, the BiNPs@NPCGS-based sensor could simultaneously det. Pb2+ and Cd2+ with detection limits of 3.2 and 4.1 nM, resp. Also, the proposed sensor could also differentiate Tl+ from Pb2+ and Cd2+. Owing to its advantages of simple prepn., environmental friendliness, high surface area, and fast electron-transfer ability, BiNPs@NPCGS showed promise for practical application in sensing heavy-metal ions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtFWgtLfF&md5=d280543df8d640bf5d9e7badc8189129
231
Wei, W.; Wang, G.; Yang, S.; Feng, X. L.; Mullen, K. Efficient Coupling of Nanoparticles to Electrochemically Exfoliated Graphene J. Am. Chem. Soc. 2015, 137, 5576– 5581 DOI: 10.1021/jacs.5b02284

Google Scholar

There is no corresponding record for this reference.
232
Lee, W. C.; Kim, K.; Park, J.; Koo, J.; Jeong, H. Y.; Lee, H.; Weitz, D. A.; Zettl, A.; Takeuchi, S. Graphene-Templated Directional Growth of an Inorganic Nanowire Nat. Nanotechnol. 2015, 10, 423– 428 DOI: 10.1038/nnano.2015.36

Google Scholar

232
Graphene-templated directional growth of an inorganic nanowire

Lee, Won Chul; Kim, Kwanpyo; Park, Jungwon; Koo, Jahyun; Jeong, Hu Young; Lee, Hoonkyung; Weitz, David A.; Zettl, Alex; Takeuchi, Shoji

Nature Nanotechnology (2015), 10 (5), 423-428CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)

Assembling inorg. nanomaterials on graphene is of interest in the development of nanodevices and nanocomposite materials, and the ability to align such inorg. nanomaterials on the graphene surface is expected to lead to improved functionalities, as has previously been demonstrated with org. nanomaterials epitaxially aligned on graphitic surfaces. However, because graphene is chem. inert, it is difficult to precisely assemble inorg. nanomaterials on pristine graphene. Previous techniques based on dangling bonds of damaged graphene, intermediate seed materials, and vapor-phase deposition at high temp. have only formed randomly oriented or poorly aligned inorg. nanostructures. The authors show that inorg. nanowires of gold(I) cyanide can grow directly on pristine graphene, aligning themselves with the zigzag lattice directions of the graphene. The nanowires are synthesized through a self-organized growth process in aq. soln. at room temp., which indicates that the inorg. material spontaneously binds to the pristine graphene surface. First-principles calcns. suggest that this assembly originates from lattice matching and π interaction to gold atoms. Using the synthesized nanowires as templates, the authors also fabricate nanostructures with controlled crystal orientations such as graphene nanoribbons with zigzag-edged directions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlt1aju7c%253D&md5=092c9f786423016721eae622e3116444
233
Yu, S. U.; Park, B.; Cho, Y.; Hyun, S.; Kim, J. K.; Kim, K. S. Simultaneous Visualization of Graphene Grain Boundaries and Wrinkles with Structural Information by Gold Deposition ACS Nano 2014, 8, 8662– 8668 DOI: 10.1021/nn503550d

Google Scholar

233
Simultaneous visualization of graphene grain boundaries and wrinkles with structural information by gold deposition

Yu, Seong Uk; Park, Beomjin; Cho, Yeonchoo; Hyun, Seung; Kim, Jin Kon; Kim, Kwang S.

ACS Nano (2014), 8 (8), 8662-8668CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Although line defects such as grain boundaries (GBs) and wrinkles are unavoidable in graphene, difficulties in identification preclude studying their impact on electronic and mech. properties. As previous methods focus on a single type of line defect, simultaneous measurements of both GBs and wrinkles with detailed structural information have not been reported. Here, we introduce effective visualization of both line defects by controlled gold deposition. Upon depositing gold on graphene, single lines and double lines of gold nanoparticles (NPs) are formed along GBs and wrinkles, resp. Moreover, it is possible to analyze whether a GB is stitched or overlapped, whether a wrinkle is standing or folded, and the width of the standing collapsed wrinkle. Theor. calcns. show that the characteristic morphol. of gold NPs is due to distinct binding energies of line defects, which are correlated to disrupting diffusion of NPs. Our approach could be further exploited to investigate the defect structures of other two-dimensional materials.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtlequr%252FI&md5=f32ef4b1094a30ff9d1a1aa441c9f6fe
234
Duong, D. L.; Han, G. H.; Lee, S. M.; Gunes, F.; Kim, E. S.; Kim, S. T.; Kim, H.; Ta, Q. H.; So, K. P.; Yoon, S. J. Probing Graphene Grain Boundaries with Optical Microscopy Nature 2012, 490, 235– 240 DOI: 10.1038/nature11562

Google Scholar

234
Probing graphene grain boundaries with optical microscopy

Duong, Dinh Loc; Han, Gang Hee; Lee, Seung Mi; Gunes, Fethullah; Kim, Eun Sung; Kim, Sung Tae; Kim, Heetae; Ta, Quang Huy; So, Kang Pyo; Yoon, Seok Jun; Chae, Seung Jin; Jo, Young Woo; Park, Min Ho; Chae, Sang Hoon; Lim, Seong Chu; Choi, Jae Young; Lee, Young Hee

Nature (London, United Kingdom) (2012), 490 (7419), 235-239CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)

Grain boundaries in graphene are formed by the joining of islands during the initial growth stage, and these boundaries govern transport properties and related device performance. Although information on the at. rearrangement at graphene grain boundaries can be obtained using transmission electron microscopy and scanning tunneling microscopy, large-scale information regarding the distribution of graphene grain boundaries is not easily accessible. Here we use optical microscopy to observe the grain boundaries of large-area graphene (grown on copper foil) directly, without transfer of the graphene. This imaging technique was realized by selectively oxidizing the underlying copper foil through graphene grain boundaries functionalized with O and OH radicals generated by UV irradn. under moisture-rich ambient conditions: selective diffusion of oxygen radicals through OH-functionalized defect sites was demonstrated by d. functional calcns. The sheet resistance of large-area graphene decreased as the graphene grain sizes increased, but no strong correlation with the grain size of the copper was revealed, in contrast to a previous report. Furthermore, the influence of graphene grain boundaries on crack propagation (initialized by bending) and termination was clearly visualized using our technique. Our approach can be used as a simple protocol for evaluating the grain boundaries of other two-dimensional layered structures, such as boron nitride and exfoliated clays.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsVGjs7%252FO&md5=19116777b7a8451c66f8f06f85eb17e2
235
Yu, S. U.; Cho, Y.; Park, B.; Kim, N.; Youn, I. S.; Son, M.; Kim, J. K.; Choi, H. C.; Kim, K. S. Fast benchtop visualization of graphene grain boundaries using adhesive properties of defects Chem. Commun. 2013, 49, 5474– 5476 DOI: 10.1039/c3cc42464b

Google Scholar

There is no corresponding record for this reference.
236
Kim, D. W.; Kim, Y. H.; Jeong, H. S.; Jung, H. T. Direct Visualization of Large-Area Graphene Domains and Boundaries by Optical Birefringency Nat. Nanotechnol. 2011, 7, 29– 34 DOI: 10.1038/nnano.2011.198

Google Scholar

236
Direct visualization of large-area graphene domains and boundaries by optical birefringency

Kim Dae Woo; Kim Yun Ho; Jeong Hyeon Su; Jung Hee-Tae

Nature nanotechnology (2011), 7 (1), 29-34 ISSN:.

The boundaries between domains in single-layer graphene strongly influence its electronic properties. However, existing approaches for domain visualization, which are based on microscopy and spectroscopy, are only effective for domains that are less than a few micrometres in size. Here, we report a simple method for the visualization of arbitrarily large graphene domains by imaging the birefringence of a graphene surface covered with nematic liquid crystals. The method relies on a correspondence between the orientation of the liquid crystals and that of the underlying graphene, which we use to determine the boundaries of macroscopic domains.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC387gtlarsg%253D%253D&md5=7120e673a201a9319ad72be86b5bd889
237
Zhang, H. M.; Yu, X. Z.; Guo, D.; Qu, B. H.; Zhang, M.; Li, Q. H.; Wang, T. H. Synthesis of Bacteria Promoted Reduced Graphene Oxide-Nickel Sulfide Networks for Advanced Supercapacitors ACS Appl. Mater. Interfaces 2013, 5, 7335– 7340 DOI: 10.1021/am401680m

Google Scholar

237
Synthesis of Bacteria Promoted Reduced Graphene Oxide-Nickel Sulfide Networks for Advanced Supercapacitors

Zhang, Haiming; Yu, Xinzhi; Guo, Di; Qu, Baihua; Zhang, Ming; Li, Qiuhong; Wang, Taihong

ACS Applied Materials & Interfaces (2013), 5 (15), 7335-7340CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

Supercapacitors with potential high power are useful and have attracted much attention recently. Graphene-based composites have been demonstrated to be promising electrode materials for supercapacitors with enhanced properties. To improve the performance of graphene-based composites further and realize their synthesis on a large scale, we report a green approach to synthesize bacteria-reduced graphene oxide-nickel sulfide (BGNS) networks. By using Bacillus subtilis as spacers, we deposited reduced graphene oxide/Ni3S2 nanoparticle composites with submillimeter pores directly onto substrate by a binder-free electrostatic spray approach to form BGNS networks. Their electrochem. capacitor performance was evaluated. Compared with stacked reduced graphene oxide-nickel sulfide (GNS) prepd. without the aid of bacteria, BGNS with unique nm-μm structure exhibited a higher specific capacitance of about 1424 F g-1 at a c.d. of 0.75 A g-1. About 67.5% of the capacitance was retained as the c.d. increased from 0.75 to 15 A g-1. At a c.d. of 75 A g-1, a specific capacitance of 406 F g-1 could still remain. The results indicate that the reduced graphene oxide-nickel sulfide network promoted by bacteria is a promising electrode material for supercapacitors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXptFehsLo%253D&md5=b8cd956646d5b1d6a8e6ea4addcca32d
238
Shi, Y.; Wang, J. Z.; Chou, S. L.; Wexler, D.; Li, H. J.; Ozawa, K.; Liu, H. K.; Wu, Y. P. Hollow Structured Li₃VO₄ Wrapped with Graphene Nanosheets in Situ Prepared by a One-Pot Template-Free Method as an Anode for Lithium-Ion Batteries Nano Lett. 2013, 13, 4715– 4720 DOI: 10.1021/nl402237u

Google Scholar

238
Hollow Structured Li3VO4 Wrapped with Graphene Nanosheets in Situ Prepared by a One-Pot Template-Free Method as an Anode for Lithium-Ion Batteries

Shi, Yi; Wang, Jia-Zhao; Chou, Shu-Lei; Wexler, David; Li, Hui-Jun; Ozawa, Kiyoshi; Liu, Hua-Kun; Wu, Yu-Ping

Nano Letters (2013), 13 (10), 4715-4720CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

To explore good anode materials of high safety, high reversible capacity, good cycling, and excellent rate capability, a Li3VO4 microbox with wall thickness of 40 nm was prepd. by a one-pot and template-free in situ hydrothermal method. In addn., its composite with graphene nanosheets of about six layers of graphene was achieved. Both of them, esp. the Li3VO4/graphene nanosheets composite, show superior electrochem. performance to the formerly reported vanadium-based anode materials. The composite shows a reversible capacity of 223 mA-h/g even at 20C (1C = 400 mA-h/g). After 500 cycles at 10C there is no evident capacity fading.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsVehsrbJ&md5=35229008a631b2539159934b12684aba
239
Hu, J. T.; Zheng, J. X.; Tian, L. L.; Duan, Y. D.; Lin, L. P.; Cui, S. H.; Peng, H.; Liu, T. C.; Guo, H.; Wang, X. W. A Core-Shell Nanohollow-γ-Fe₂O₃@Graphene Hybrid Prepared through the Kirkendall Process as a High Performance Anode Material for Lithium Ion Batteries Chem. Commun. 2015, 51, 7855– 7858 DOI: 10.1039/C5CC01195G

Google Scholar

There is no corresponding record for this reference.
240
Sengar, S. K.; Mehta, B. R.; Kumar, R.; Singh, V. In-Flight Gas Phase Growth of Metal/Multilayer Graphene Core Shell Nanoparticles with Controllable Sizes Sci. Rep. 2013, 3, 2814 DOI: 10.1038/srep02814

Google Scholar

240
In-flight gas phase growth of metal/multi layer graphene core shell nanoparticles with controllable sizes

Sengar Saurabh K; Mehta B R; Kumar Rakesh; Singh Vinod

Scientific reports (2013), 3 (), 2814 ISSN:.

In this report, we present a general method for a continuous gas-phase synthesis of size-selected metal/multi layer graphene (MLG) core shell nanoparticles having a narrow size distribution of metal core and MLG shell for direct deposition onto any desired substrate kept under clean vacuum conditions. Evolution of MLG signature is clearly observed as the metal-carbon agglomerates get transformed to well defined metal/MLG core shell nanoparticles during their flight through the sintering zone. The growth takes place via an intermediate state of alloy nanoparticle (Pd-carbon) or composite nanoparticle (Cu-carbon), depending upon the carbon solubility in the metal and relative surface energy values. It has been also shown that metal/MLG nanoparticles can be converted to graphene shells. This study will have a large impact on how graphene or graphene based composite nanostructures can be grown and deposited in applications requiring controllable dimensions, varied substrate choice, large area and large scale depositions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2c%252FnsVeksA%253D%253D&md5=9a7cbde5b986c9cb11586ea06b70a9a2
241
Moon, H.; Kumar, D.; Kim, H.; Sim, C.; Chang, J. H.; Kim, J. M.; Kim, H.; Lim, D. K. Amplified Photoacoustic Performance and Enhanced Photothermal Stability of Reduced Graphene Oxide Coated Gold Nanorods for Sensitive Photo acoustic Imaging ACS Nano 2015, 9, 2711– 2719 DOI: 10.1021/nn506516p

Google Scholar

There is no corresponding record for this reference.
242
Si, Y.; Samulski, E. T. Exfoliated Graphene Separated by Platinum Nanoparticles Chem. Mater. 2008, 20, 6792– 6797 DOI: 10.1021/cm801356a

Google Scholar

242
Exfoliated graphene separated by platinum nanoparticles

Si, Yongchao; Samulski, Edward T.

Chemistry of Materials (2008), 20 (21), 6792-6797CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)

Aggregation of isolated graphene sheets during drying graphene dispersions leads to a loss of its ultrahigh surface area advantage as a 2D nanomaterial. We report a metal nanoparticle-graphene composite with a partially exfoliated graphene morphol. derived from drying aq. dispersions of platinum nanoparticles adhered to graphene. Pt nanoparticles with diams. spanning several nanometers are adhered to graphene by a chem. route involving the redn. of metal precursors in a graphene dispersion. Face-to-face aggregation of graphene sheets is arrested by 3-4 nm fcc Pt crystallites on the graphene surfaces, and in the resulting jammed Pt-graphene composite, the Pt acts as spacers resulting in mech. exfoliated, high-surface-area material of potential interest for supercapacitors and fuel cells.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXht1CgtrvE&md5=cdb49927d288cbe16d95dd0c2b4a80e7
243
Buglione, L.; Bonanni, A.; Ambrosi, A.; Pumera, M. Gold Nanospacers Greatly Enhance the Capacitance of Electrochemically Reduced Graphene ChemPlusChem 2012, 77, 71– 73 DOI: 10.1002/cplu.201100016

Google Scholar

There is no corresponding record for this reference.
244
Wu, Z.-S.; Ren, W.; Wen, L.; Gao, L.; Zhao, J.; Chen, Z.; Zhou, G.; Li, F.; Cheng, H.-M. Graphene Anchored with Co₃O₄ Nanoparticles as Anode of Lithium IonBatteries with Enhanced Reversible Capacity and Cyclic Performance ACS Nano 2010, 4, 3187– 3194 DOI: 10.1021/nn100740x

Google Scholar

There is no corresponding record for this reference.
245
Liu, Y.; Wang, R.; Yan, X. Synergistic Effect between Ultra-Small Nickel Hydroxide Nanoparticles and Reduced Graphene Oxide Sheets for the Application in High-Performance Asymmetric Supercapacitor Sci. Rep. 2015, 5, 11095 DOI: 10.1038/srep11095

Google Scholar

245
Synergistic Effect between Ultra-Small Nickel Hydroxide Nanoparticles and Reduced Graphene Oxide sheets for the Application in High-Performance Asymmetric Supercapacitor

Liu Yonghuan; Wang Rutao; Yan Xingbin

Scientific reports (2015), 5 (), 11095 ISSN:.

Nanoscale electrode materials including metal oxide nanoparticles and two-dimensional graphene have been employed for designing supercapacitors. However, inevitable agglomeration of nanoparticles and layers stacking of graphene largely hamper their practical applications. Here we demonstrate an efficient co-ordination and synergistic effect between ultra-small Ni(OH)2 nanoparticles and reduced graphene oxide (RGO) sheets for synthesizing ideal electrode materials. On one hand, to make the ultra-small Ni(OH)2 nanoparticles work at full capacity as an ideal pseudocapacitive material, RGO sheets are employed as an suitable substrate to anchor these nanoparticles against agglomeration. As a consequence, an ultrahigh specific capacitance of 1717 F g(-1) at 0.5 A g(-1) is achieved. On the other hand, to further facilitate ion transfer within RGO sheets as an ideal electrical double layer capacitor material, the ultra-small Ni(OH)2 nanoparticles are introduced among RGO sheets as the recyclable sacrificial spacer to prevent the stacking. The resulting RGO sheets exhibit superior rate capability with a high capacitance of 182 F g(-1) at 100 A g(-1). On this basis, an asymmetric supercapacitor is assembled using the two materials, delivering a superior energy density of 75 Wh kg(-1) and an ultrahigh power density of 40 000 W kg(-1).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2Mbhslymuw%253D%253D&md5=dd8fee7c83b21267ca15a7ca6a3b3785
246
Tiwari, J. N.; Kemp, K. C.; Nath, K.; Tiwari, R. N.; Nam, H.-G.; Kim, K. S. Interconnected Pt-Nanodendrite/DNA/Reduced-Graphene-Oxide Hybrid Showing Remarkable Oxygen Reduction Activity and Stability ACS Nano 2013, 7, 9223– 9231 DOI: 10.1021/nn4038404

Google Scholar

246
Interconnected Pt-Nanodendrite/DNA/Reduced-Graphene-Oxide Hybrid Showing Remarkable Oxygen Reduction Activity and Stability

Tiwari, Jitendra N.; Kemp, Kingsley Christian; Nath, Krishna; Tiwari, Rajanish N.; Nam, Hong-Gil; Kim, Kwang S.

ACS Nano (2013), 7 (10), 9223-9231CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Controlling the morphol. and size of platinum nanodendrites (PtDs) is a key factor in improving their catalytic activity and stability. Here, we report the synthesis is reported of PtDs on genomic-double-stranded-DNA/reduced-graphene-oxide (gdsDNA/rGO) by the NaBH4 redn. of H2PtCl6 in the presence of plant gdsDNA. Compared to industrially adopted catalysts (i.e., state-of-the-art Pt/C catalyst, Pt/rGO, Pt3Co, etc.), the as-synthesized PtDs/gdsDNA/rGO hybrid displays very high oxygen redn. reaction (ORR) catalytic activities (much higher than the 2015 U.S. Department of Energy (DOE) target values), which are the rate-detg. steps in electrochem. energy devices, in terms of onset-potential, half-wave potential, specific-activity, mass-activity, stability, and durability. Moreover, the hybrid exhibits a highly stable mass activity for the ORR over a wide pH range of 1-13. These exceptional properties would make the hybrid applicable in next-generation electrochem. energy devices.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtlKktL7O&md5=cc0d3506d0f584de37fa2ef84aa3eaa7
247
Tiwari, J. N.; Nath, K.; Kumar, S.; Tiwari, R. N.; Kemp, K. C.; Le, N. H.; Youn, D. H.; Lee, J. S.; Kim, K. S. Stable Platinum Nanoclusters on Genomic DNA-Graphene Oxide with a High Oxygen Reduction Reaction Activity Nat. Commun. 2013, 4, 2221 DOI: 10.1038/ncomms3221

Google Scholar

247
Stable platinum nanoclusters on genomic DNA-graphene oxide with a high oxygen reduction reaction activity

Tiwari Jitendra N; Nath Krishna; Kumar Susheel; Tiwari Rajanish N; Kemp K Christian; Le Nhien H; Youn Duck Hyun; Lee Jae Sung; Kim Kwang S

Nature communications (2013), 4 (), 2221 ISSN:.

Nanosize platinum clusters with small diameters of 2-4 nm are known to be excellent catalysts for the oxygen reduction reaction. The inherent catalytic activity of smaller platinum clusters has not yet been reported due to a lack of preparation methods to control their size (<2 nm). Here we report the synthesis of platinum clusters (diameter ≤1.4 nm) deposited on genomic double-stranded DNA-graphene oxide composites, and their high-performance electrocatalysis of the oxygen reduction reaction. The electrochemical behaviour, characterized by oxygen reduction reaction onset potential, half-wave potential, specific activity, mass activity, accelerated durability test (10,000 cycles) and cyclic voltammetry stability (10,000 cycles) is attributed to the strong interaction between the nanosize platinum clusters and the DNA-graphene oxide composite, which induces modulation in the electronic structure of the platinum clusters. Furthermore, we show that the platinum cluster/DNA-graphene oxide composite possesses notable environmental durability and stability, vital for high-performance fuel cells and batteries.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3sflsVWktw%253D%253D&md5=c1958b96d9871407595cfb085dfbc9fc
248
Huang, Y. X.; Xie, J. F.; Zhang, X.; Xiong, L.; Yu, H. Q. Reduced Graphene Oxide Supported Palladium Nanoparticles via Photoassisted Citrate Reduction for Enhanced Electrocatalytic Activities ACS Appl. Mater. Interfaces 2014, 6, 15795– 15801 DOI: 10.1021/am504664r

Google Scholar

248
Reduced Graphene Oxide Supported Palladium Nanoparticles via Photoassisted Citrate Reduction for Enhanced Electrocatalytic Activities

Huang, Yu-Xi; Xie, Jia-Fang; Zhang, Xing; Xiong, Lu; Yu, Han-Qing

ACS Applied Materials & Interfaces (2014), 6 (18), 15795-15801CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

Reduced graphene oxide (rGO) supported Pd nanoparticles (Pd NPs) with a size of ∼3 nm were synthesized using 1-pot photoassisted citrate redn. This synthetic approach allows for the formation and assembly of Pd NPs onto the rGO surface with a desired size and can be readily used for other metal NP prepn. The prepd. rGO-Pd exhibited 5.2 times higher mass activity for EtOH oxidn. reaction than the com. Pt/C (Pt/C). In the O redn. reaction tests, rGO-Pd exhibited comparable activity compared with Pt/C and maintained its high performance after 4000 cycles of potential sweep. The authors' synthetic approach is effective for prepg. graphene-supported metal NPs with excellent activity and stability in EtOH oxidn. and O redn. reactions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVWltb7F&md5=29153d13d6d1223a0b7745eea9612efd
249
Yin, H. J.; Tang, H. J.; Wang, D.; Gao, Y.; Tang, Z. Y. Facile Synthesis of Surfactant-Free Au Cluster/Graphene Hybrids for High-Performance Oxygen Reduction Reaction ACS Nano 2012, 6, 8288– 8297 DOI: 10.1021/nn302984x

Google Scholar

249
Facile Synthesis of Surfactant-Free Au Cluster/Graphene Hybrids for High-Performance Oxygen Reduction Reaction

Yin, Huajie; Tang, Hongjie; Wang, Dan; Gao, Yan; Tang, Zhiyong

ACS Nano (2012), 6 (9), 8288-8297CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Non-Pt noble metal clusters like Au clusters are believed to be promising high performance catalysts for the oxygen redn. reaction (ORR) at the cathode of fuel cells, but they still suffer big problems during the catalysis reactions, such as a large amt. of the capping agents being on the surface and easy occurrence of dissoln. and aggregation. To overcome these obstacles, here, we present a novel and general strategy to grow ultrafine Au clusters and other metal (Pt, Pd) clusters on the reduced graphene oxide (rGO) sheets without any addnl. protecting mol. or reductant. Compared with the currently generally adopted nanocatalysts, including com. Pt/C, rGO sheets, Au nanoparticle/rGO hybrids, and thiol-capped Au clusters of the same sizes, the as-synthesized Au cluster/rGO hybrids display an impressive eletrocatalytic performance toward ORR, for instance, high onset potential, superior methanol tolerance, and excellent stability.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1OktLzO&md5=3f492ab4335e1623f45eb7e53cdfd414
250
Li, Y.; Yu, Y.; Wang, J.-G.; Song, J.; Li, Q.; Dong, M.; Liu, C.-J. CO Oxidation over Graphene Supported Palladium Catalyst Appl. Catal., B 2012, 125, 189– 196 DOI: 10.1016/j.apcatb.2012.05.023

Google Scholar

250
CO oxidation over graphene supported palladium catalyst

Li, Yingzhi; Yu, Yue; Wang, Jian-Guo; Song, Jie; Li, Qiang; Dong, Mingdong; Liu, Chang-Jun

Applied Catalysis, B: Environmental (2012), 125 (), 189-196CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)

Graphene-supported Pd catalyst was prepd. using the conventional impregnation and hydrogen redn. method. Highly dispersed nanoparticles are formed on the support graphene. The DFT study and the catalyst characterization using Raman and XPS confirm that the oxygen contg. groups play an important role in stabilizing Pd clusters on graphene. The first layer of the metal particle mainly presents as PdOx. The graphene supported Pd catalyst shows superior catalytic activity and high stability for CO oxidn. The kinetic studies indicate that CO oxidn. over the graphene supported Pd catalyst follows the Langmuir-Hinshelwood (L-H) mechanism.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtFCmtrjL&md5=d30209aa9bed4c618602757816521c84
251
Grayfer, E. D.; Kibis, L. S.; Stadnichenko, A. I.; Vilkov, O. Y.; Boronin, A. I.; Slavinskaya, E. M.; Stonkus, O. A.; Fedorov, V. E. Ultradisperse Pt Nanoparticles Anchored on Defect Sites in Oxygen-Free Few-Layer Graphene and Their Catalytic Properties in CO Oxidation Carbon 2015, 89, 290– 299 DOI: 10.1016/j.carbon.2015.03.050

Google Scholar

251
Ultradisperse Pt nanoparticles anchored on defect sites in oxygen-free few-layer graphene and their catalytic properties in CO oxidation

Grayfer, Ekaterina D.; Kibis, Lidiya S.; Stadnichenko, Andrey I.; Vilkov, Oleg Yu.; Boronin, Andrei I.; Slavinskaya, Elena M.; Stonkus, Olga A.; Fedorov, Vladimir E.

Carbon (2015), 89 (), 290-299CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

Highly uniform and cryst. ultradisperse Pt nanoparticles with av. sizes of 2.4 nm were deposited on oxygen-free few-layer graphene (FLG) by polyol redn. method without any addnl. protective agents. The samples were analyzed by Raman spectroscopy, photoelectron spectroscopy using synchrotron radiation and high-resoln. transmission electron microscopy. The expts. showed that metal nanoparticles were mostly stabilized at defect sites of the FLG support in the absence of oxygen functionalities. Catalytic properties of the samples were tested in CO oxidn. reaction. For Pt nanoparticles forming agglomerates an oscillatory behavior under catalytic reaction conditions was obsd. for the first time for metal-graphene catalysts.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsFGlur4%253D&md5=93f6442f1f0bf85dfd143bc4aa6c8b25
252
Zhang, C.; Lv, W.; Yang, Q.; Liu, Y. Graphene Supported Nanoparticles of Pt–Ni for CO Oxidation Appl. Surf. Sci. 2012, 258, 7795– 7800 DOI: 10.1016/j.apsusc.2012.03.131

Google Scholar

There is no corresponding record for this reference.
253
Qu, L. T.; Liu, Y.; Baek, J. B.; Dai, L. M. Nitrogen-Doped Graphene as Efficient Metal-Free Electrocatalyst for Oxygen Reduction in Fuel Cells ACS Nano 2010, 4, 1321– 1326 DOI: 10.1021/nn901850u

Google Scholar

253
Nitrogen-Doped Graphene as Efficient Metal-Free Electrocatalyst for Oxygen Reduction in Fuel Cells

Qu, Liangti; Liu, Yong; Baek, Jong-Beom; Dai, Liming

ACS Nano (2010), 4 (3), 1321-1326CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Nitrogen-doped graphene (N-graphene) was synthesized by CVD of methane in the presence of ammonia. The resultant N-graphene was demonstrated to act as a metal-free electrode with a much better electrocatalytic activity, long-term operation stability, and tolerance to crossover effect than platinum for oxygen redn. via a four-electron pathway in alk. fuel cells. This is the 1st report on the use of graphene and its derivs. as metal-free catalysts for oxygen redn. The important role of N-doping to oxygen redn. reaction (ORR) can be applied to various carbon materials for the development of other metal-free efficient ORR catalysts for fuel cell applications, even new catalytic materials for applications beyond fuel cells.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhvFOru7s%253D&md5=f174f231c286b64b62a34ac8d8463732
254
Yang, Z.; Yao, Z.; Li, G. F.; Fang, G. Y.; Nie, H. G.; Liu, Z.; Zhou, X. M.; Chen, X.; Huang, S. M. Sulfur-Doped Graphene as an Efficient Metal-free Cathode Catalyst for Oxygen Reduction ACS Nano 2012, 6, 205– 211 DOI: 10.1021/nn203393d

Google Scholar

254
Sulfur-Doped Graphene as an Efficient Metal-free Cathode Catalyst for Oxygen Reduction

Yang, Zhi; Yao, Zhen; Li, Guifa; Fang, Guoyong; Nie, Huagui; Liu, Zheng; Zhou, Xuemei; Chen, Xi'an; Huang, Shaoming

ACS Nano (2012), 6 (1), 205-211CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Tailoring the electronic arrangement of graphene by doping is a practical strategy for producing significantly improved materials for the O-redn. reaction (ORR) in fuel cells (FCs). Recent studies proved that the C materials doped with the elements, which have the larger (N) or smaller (P, B) electroneg. atoms than C such as N-doped C nanotubes (CNTs), P-doped graphite layers and B-doped CNTs, also showed pronounced catalytic activity. Herein, the graphenes doped with the elements, which have the similar electronegativity with C such as S and Se, can also exhibit better catalytic activity than the com. Pt/C in alk. media, indicating that these doped graphenes hold great potential for a substitute for Pt-based catalysts in FCs. The exptl. results are believed to be significant because they not only give further insight into the ORR mechanism of these metal-free doped C materials, but also open a way to fabricate other new low-cost NPMCs with high electrocatalytic activity by a simple, economical, and scalable approach for real FC applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhs1OjtbrN&md5=e5861429d3b9a9dbb423b3c96fd22c05
255
Zhang, C. Z.; Mahmood, N.; Yin, H.; Liu, F.; Hou, Y. L. Synthesis of Phosphorus-Doped Graphene and its Multifunctional Applications for Oxygen Reduction Reaction and Lithium Ion Batteries Adv. Mater. 2013, 25, 4932– 4937 DOI: 10.1002/adma.201301870

Google Scholar

255
Synthesis of Phosphorus-Doped Graphene and its Multifunctional Applications for Oxygen Reduction Reaction and Lithium Ion Batteries

Zhang, Chenzhen; Mahmood, Nasir; Yin, Han; Liu, Fei; Hou, Yanglong

Advanced Materials (Weinheim, Germany) (2013), 25 (35), 4932-4937CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

Synthesis of phosphorus-doped graphene and its multifunctional applications for oxygen redn. reaction and lithium ion batteries are discussed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtFelsLvF&md5=efeb096dddd9f1dd78a85d91a3c1495c
256
Wang, L.; Ambrosi, A.; Pumera, M. ″Metal-Free″ Catalytic Oxygen Reduction Reaction on Heteroatom-Doped Graphene is Caused by Trace Metal Impurities Angew. Chem., Int. Ed. 2013, 52, 13818– 13821 DOI: 10.1002/anie.201309171

Google Scholar

There is no corresponding record for this reference.
257
Wang, L.; Ambrosi, A.; Pumera, M. Could Carbonaceous Impurities in Reduced Graphenes be Responsible for Some of Their Extraordinary Electrocatalytic Activities? Chem. - Asian J. 2013, 8, 1200– 1204 DOI: 10.1002/asia.201300122

Google Scholar

257
Could Carbonaceous Impurities in Reduced Graphenes be Responsible for Some of Their Extraordinary Electrocatalytic Activities?

Wang, Lu; Ambrosi, Adriano; Pumera, Martin

Chemistry - An Asian Journal (2013), 8 (6), 1200-1204CODEN: CAAJBI; ISSN:1861-4728. (Wiley-VCH Verlag GmbH & Co. KGaA)

Thermally and chem. reduced graphene materials contain significant amts. of carbonaceous impurities that are similar in structure to amorphous carbon. Herein, we show that the claimed electrocatalytic activities of these materials for the oxidn. of NADH, acetaminophen, and hydroquinone are mainly due to the presence of carbonaceous impurities.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXksVKqs74%253D&md5=97a779d8de0502a8f308df0cda641fd5
258
Yang, J.; Voiry, D.; Ahn, S. J.; Kang, D.; Kim, A. Y.; Chhowalla, M.; Shin, H. S. Two-Dimensional Hybrid Nanosheets of Tungsten Disulfide and Reduced Graphene Oxide as Catalysts for Enhanced Hydrogen Evolution Angew. Chem., Int. Ed. 2013, 52, 13751– 13754 DOI: 10.1002/anie.201307475

Google Scholar

258
Two-Dimensional Hybrid Nanosheets of Tungsten Disulfide and Reduced Graphene Oxide as Catalysts for Enhanced Hydrogen Evolution

Yang, Jieun; Voiry, Damien; Ahn, Seong Joon; Kang, Dongwoo; Kim, Ah Young; Chhowalla, Manish; Shin, Hyeon Suk

Angewandte Chemie, International Edition (2013), 52 (51), 13751-13754CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

The authors develop a hydrothermal method for synthesis of WS2 nanosheets and then integrate rGO nanosheets into the reactor to fabricate novel WS2/rGO hybrids. The authors report detailed structural analyses of the synthesized products and investigate their potential catalysts for the hydrogen evolution reaction (HER). The primary uniqueness of the author's work is the synthesis of WS2 and rGO/WS2 nanosheets using a scalable hydrothermal method and their implementation as efficient catalysts for HER.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslCqsrvJ&md5=eccd15f2fa1a4ede1d674f2c13623cfa
259
Peng, S. J.; Li, L. L.; Han, X. P.; Sun, W. P.; Srinivasan, M.; Mhaisalkar, S. G.; Cheng, F. Y.; Yan, Q. Y.; Chen, J.; Ramakrishna, S. Cobalt Sulfide Nanosheet/Graphene/Carbon Nanotube Nanocomposites as Flexible Electrodes for Hydrogen Evolution Angew. Chem., Int. Ed. 2014, 53, 12594– 12599 DOI: 10.1002/anie.201408876

Google Scholar

259
Cobalt Sulfide Nanosheet/Graphene/Carbon Nanotube Nanocomposites as Flexible Electrodes for Hydrogen Evolution

Peng, Shengjie; Li, Linlin; Han, Xiaopeng; Sun, Wenping; Srinivasan, Madhavi; Mhaisalkar, Subodh G.; Cheng, Fangyi; Yan, Qingyu; Chen, Jun; Ramakrishna, Seeram

Angewandte Chemie, International Edition (2014), 53 (46), 12594-12599CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

Flexible three-dimensional (3D) nanoarchitectures have received tremendous interest recently because of their potential applications in wearable electronics, roll-up displays, and other devices. The design and fabrication of a flexible and robust electrode based on Co sulfide/reduced graphene oxide/C nanotube (CoS2/RGO-CNT) nanocomposites are reported. An efficient hydrothermal process combined with vacuum filtration was used to synthesize such composite architecture, which was then embedded in a porous CNT network. This conductive and robust film is evaluated as electrocatalyst for the H evolution reaction. The synergistic effect of CoS2, graphene, and CNTs leads to unique CoS2/RGO-CNT nanoarchitectures, the HER activity of which is among the highest for nonnoble metal electrocatalysts, showing 10 mA cm-2 c.d. at ∼142 mV overpotentials and a high electrochem. stability.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVGksL3I&md5=87d21c61b035f47a0ae920bfa4f3c53a
260
He, C. Y.; Tao, J. Z. Synthesis of Nanostructured Clean Surface Molybdenum Carbides on Graphene Sheets as Efficient and Stable Hydrogen Evolution Reaction Catalysts Chem. Commun. 2015, 51, 8323– 8325 DOI: 10.1039/C5CC01240F

Google Scholar

260
Synthesis of nanostructured clean surface molybdenum carbides on graphene sheets as efficient and stable hydrogen evolution reaction catalysts

He, Chunyong; Tao, Juzhou

Chemical Communications (Cambridge, United Kingdom) (2015), 51 (39), 8323-8325CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)

Small size molybdenum carbides (2.5 nm for MoC and 5.0 nm for Mo2C) with clean surface on graphene were prepd. for efficient and stable hydrogen evolution reaction catalysts.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmt1Wrtbs%253D&md5=77e4a8dd5bc8ba3c57d1722d310431de
261
Youn, D. H.; Han, S.; Kim, J. Y.; Kim, J. Y.; Park, H.; Choi, S. H.; Lee, J. S. Highly Active and Stable Hydrogen Evolution Electrocatalysts Based on Molybdenum Compounds on Carbon Nanotube-Graphene Hybrid Support ACS Nano 2014, 8, 5164– 5173 DOI: 10.1021/nn5012144

Google Scholar

261
Highly Active and Stable Hydrogen Evolution Electrocatalysts Based on Molybdenum Compounds on Carbon Nanotube-Graphene Hybrid Support

Youn, Duck Hyun; Han, Suenghoon; Kim, Jae Young; Kim, Jae Yul; Park, Hunmin; Choi, Sun Hee; Lee, Jae Sung

ACS Nano (2014), 8 (5), 5164-5173CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Highly active and stable electrocatalysts for H evolution were developed from Mo compds. (Mo2C, Mo2N, and MoS2) on C nanotube (CNT)-graphene hybrid support via a modified urea-glass route. By a simple modification of synthetic variables, the final phases are easily controlled from carbide, nitride to sulfide with homogeneous dispersion of nanocrystals on the CNT-graphene support. Among the prepd. catalysts, Mo2C/CNT-graphene shows the highest activity for H evolution reaction with a small onset overpotential of 62 mV and Tafel slope of 58 mV/dec as well as an excellent stability in acid media. Such enhanced catalytic activity may originate from its low H binding energy and high cond. Also, the CNT-graphene hybrid support plays crucial roles to enhance the activity of Mo compds. by alleviating aggregation of the nanocrystals, providing a large area to contact with electrolyte, and facilitating the electron transfer.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXntFOmsbc%253D&md5=7feb6394caf9da2b6dd8ddd3468f7667
262
Bai, S.; Wang, C. M.; Deng, M. S.; Gong, M.; Bai, Y.; Jiang, J.; Xiong, Y. J. Surface Polarization Matters: Enhancing the Hydrogen-Evolution Reaction by Shrinking Pt Shells in Pt-Pd-Graphene Stack Structures Angew. Chem., Int. Ed. 2014, 53, 12120– 12124 DOI: 10.1002/anie.201406468

Google Scholar

262
Surface Polarization Matters: Enhancing the Hydrogen-Evolution Reaction by Shrinking Pt Shells in Pt-Pd-Graphene Stack Structures

Bai, Song; Wang, Chengming; Deng, Mingsen; Gong, Ming; Bai, Yu; Jiang, Jun; Xiong, Yujie

Angewandte Chemie, International Edition (2014), 53 (45), 12120-12124CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

Surface charge state plays an important role in tuning the catalytic performance of nanocrystals in various reactions. Herein, we report a synthetic approach to unique Pt-Pd-graphene stack structures with controllable Pt shell thickness. These unique hybrid structures allow us to correlate the Pt thickness with performance in the hydrogen-evolution reaction (HER). The HER activity increases with a decrease in the Pt thickness, which is well explained by surface polarization mechanism as suggested by first-principles simulations. In this hybrid system, the difference in work functions of Pt and Pd results in surface polarization on the Pt surface, tuning its charge state for hydrogen redn. Meanwhile, the supporting graphene provides two-dimensional channels for efficient charge transport, improving the HER activities. This work opens up possibilities of reducing Pt usage while achieving high HER performance.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVWqtrzK&md5=8e95fea009b267349957bd038b98d296
263
Yan, H. J.; Tian, C. G.; Wang, L.; Wu, A. P.; Meng, M. C.; Zhao, L.; Fu, H. G. Phosphorus-Modified Tungsten Nitride/Reduced Graphene Oxide as a High-Performance, Non-Noble-Metal Electrocatalyst for the Hydrogen Evolution Reaction Angew. Chem., Int. Ed. 2015, 54, 6325– 6329 DOI: 10.1002/anie.201501419

Google Scholar

263
Phosphorus-Modified Tungsten Nitride/Reduced Graphene Oxide as a High-Performance, Non-Noble-Metal Electrocatalyst for the Hydrogen Evolution Reaction

Yan, Haijing; Tian, Chungui; Wang, Lei; Wu, Aiping; Meng, Meichen; Zhao, Lu; Fu, Honggang

Angewandte Chemie, International Edition (2015), 54 (21), 6325-6329CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

Phosphorus-modified tungsten nitride/reduced graphene oxide (P-WN/rGO) is designed as a highly-efficient, low-cost electrocatalyst for the hydrogen evolution reaction (HER). WN (ca. 3 nm in size) on rGO is first synthesized by using the H3[PO4(W3O9)4] cluster as a W source. Followed by phosphorization, the particle size increase slightly to about 4 nm with a P content of 2.52 at.%. The interaction of P with rGO and WN results in an obvious increase of work function, being close to Pt metal. The P-WN/rGO exhibits low onset overpotential of 46 mV, Tafel slope of 54 mV dec-1, and a large exchange c.d. of 0.35 mA cm-2 in acid media. It requires overpotential of only 85 mV at c.d. of 10 mA cm-2, while remaining with good stability in accelerated durability testing. This work shows that the modification with a second anion is powerful way to design new catalysts for HER.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsVOgs78%253D&md5=15991192dc2f01287254838efe1cf19d
264
Chen, Y.; Zhu, Q. L.; Tsumori, N.; Xu, Q. Immobilizing Highly Catalytically Active Noble Metal Nanoparticles on Reduced Graphene Oxide: A Non-Noble Metal Sacrificial Approach J. Am. Chem. Soc. 2015, 137, 106– 109 DOI: 10.1021/ja511511q

Google Scholar

264
Immobilizing Highly Catalytically Active Noble Metal Nanoparticles on Reduced Graphene Oxide: A Non-Noble Metal Sacrificial Approach

Chen, Yao; Zhu, Qi-Long; Tsumori, Nobuko; Xu, Qiang

Journal of the American Chemical Society (2015), 137 (1), 106-109CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

In this work, we have developed a non-noble metal sacrificial approach for the first time to successfully immobilize highly dispersed AgPd nanoparticles on reduced graphene oxide (RGO). The Co3(BO3)2 co-pptd. with AgPd nanoparticles and subsequently sacrificed by acid etching effectively prevents the primary AgPd particles from aggregation. The resulted ultrafine AgPd nanoparticles exhibit the highest activity (turnover frequency, 2739 h-1 at 323 K) among all the heterogeneous catalysts for the dehydrogenation of formic acid to generate hydrogen without CO impurity. The sacrificial approach opens up a new avenue for the development of high-performance metal nanocatalysts.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFyhtLrK&md5=b9c1dbe93d61d70cd9a0c5ebe2f1f118
265
Yang, J. M.; Wang, S. A.; Sun, C. L.; Ger, M. D. Synthesis of size-selected Pt Nanoparticles Supported on Sulfonated Graphene with Polyvinyl Alcohol for Methanol Oxidation in Alkaline Solutions J. Power Sources 2014, 254, 298– 305 DOI: 10.1016/j.jpowsour.2013.12.120

Google Scholar

265
Synthesis of size-selected Pt nanoparticles supported on sulfonated graphene with polyvinyl alcohol for methanol oxidation in alkaline solutions

Yang, Jen-Ming; Wang, Sheng-An; Sun, Chia-Liang; Ger, Ming-Der

Journal of Power Sources (2014), 254 (), 298-305CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)

The size-selected platinum (Pt) nanoparticles are loaded on sulfonated graphene with polyvinyl alc. (PVA) as the conductive polymer for fuel-cell applications. Methanol oxidn. reactions and reliability of various catalysts based on carbon black, graphene, and sulfonated graphene catalyst supports are compared under alk. conditions. When PVA is used as the conductive polymer in place of Nafion, both the electrochem. active surface area (ECSA) and the methanol oxidn. property were superior, irresp. of the catalyst and support. However, the catalyst with Pt on sulfonated graphene (Pt/sG) outperforms those on other supports. For methanol oxidn., the catalyst decay occurs with a decay of only 9.06% for Pt/sG. Probably the sulfonate functional group on graphene not only improves catalytic activity but can also enhance catalyst reliability.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFOku7w%253D&md5=5d87d12390a7ef6c097ef84d9a2fa3c3
266
Chen, Y.; Yang, J.; Yang, Y.; Peng, Z.; Li, J.; Mei, T.; Wang, J.; Hao, M.; Chen, Y.; Xiong, W. A Facile Strategy to Synthesize Three-Dimensional Pd@Pt Core-Shell Nanoflowers Supported on Graphene Nanosheets as Enhanced Nanoelectrocatalysts for Methanol Oxidation Chem. Commun. 2015, 51, 10490– 10493 DOI: 10.1039/C5CC01803J

Google Scholar

266
A facile strategy to synthesize three-dimensional Pd@Pt core-shell nanoflowers supported on graphene nanosheets as enhanced nanoelectrocatalysts for methanol oxidation

Chen, Yi; Yang, Jia; Yang, Ying; Peng, Zhiyao; Li, Jinhua; Mei, Tao; Wang, Jianying; Hao, Ming; Chen, Yalin; Xiong, Weilai; Zhang, Liu; Wang, Xianbao

Chemical Communications (Cambridge, United Kingdom) (2015), 51 (52), 10490-10493CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)

Here the authors demonstrate for the 1st time a H2O-based surfactant-free synthesis of 3-dimensional porous Pd@Pt core-shell nanoflowers on graphene. The obtained Pd@Pt-graphene hybrids exhibited substantially enhanced electrocatalytic activity and stability relative to the com. Pt/C catalyst originating from this exquisite nanoarchitecture for 3-dimensional mol. accessibility and graphene-metal interaction.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnsVehsr4%253D&md5=983e2b6ceef3e13282424acacf4f5bcc
267
Metin, O.; Ho, S. F.; Alp, C.; Can, H.; Mankin, M. N.; Gultekin, M. S.; Chi, M. F.; Sun, S. H. Ni/Pd Core/Shell Nanoparticles Supported on Graphene as a Highly Active and Reusable Catalyst for Suzuki-Miyaura Cross-Coupling Reaction Nano Res. 2013, 6, 10– 18 DOI: 10.1007/s12274-012-0276-4

Google Scholar

267
Ni/Pd core/shell nanoparticles supported on graphene as a highly active and reusable catalyst for Suzuki-Miyaura cross-coupling reaction

Metin, Oender; Ho, Sally Fae; Alp, Cemalettin; Can, Hasan; Mankin, Max N.; Gueltekin, Mehmet Serdar; Chi, Miaofang; Sun, Shouheng

Nano Research (2013), 6 (1), 10-18CODEN: NRAEB5; ISSN:1998-0000. (Springer GmbH)

Monodisperse Ni/Pd core/shell nanoparticles (NPs) have been synthesized by sequential redn. of nickel(II) acetate and palladium(II) bromide in oleylamine (OAm) and trioctylphosphine (TOP). The Ni/Pd NPs have a narrow size distribution with a mean particle size of 10 nm and a std. deviation of 5% with respect to the particle diam. Mechanistic studies showed that the presence of TOP was essential to control the reductive decompn. of Ni-TOP and Pd-TOP, and the formation of Ni/Pd core/shell NPs. Using the current synthetic protocol, the compn. of the Ni/Pd within the core/shell structure can be readily tuned by simply controlling the initial molar ratio of the Ni and Pd salts. The as-synthesized Ni/Pd core/shell NPs were supported on graphene (G) and used as catalyst in Suzuki-Miyaura cross-coupling reactions. Among three different kinds of Ni/Pd NPs tested, the Ni/Pd (Ni/Pd = 3/2) NPs were found to be the most active catalyst for the Suzuki-Miyaura cross-coupling of arylboronic acids with aryl iodides, bromides and even chlorides in a dimethylformamide/water mixt. by using K2CO3 as a base at 110 °C. The G-Ni/Pd was also stable and reusable, providing 98% conversion after the 5th catalytic run without showing any noticeable Ni/Pd compn. change. The G-Ni/Pd structure reported in this paper combines both the efficiency of a homogeneous catalyst and the durability of a heterogeneous catalyst, and is promising catalyst candidate for various Pd-based catalytic applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtFWrtrc%253D&md5=ea6aa6b18fce78babd184c461e4062bc
268
Putta, C.; Sharavath, V.; Sarkar, S.; Ghosh, S. Palladium Nanoparticles on Beta-Cyclodextrin Functionalised Graphene Nanosheets: A Supramolecular Based Heterogeneous Catalyst for C-C Coupling Reactions under Green Reaction Conditions RSC Adv. 2015, 5, 6652– 6660 DOI: 10.1039/C4RA14323J

Google Scholar

268
Palladium nanoparticles on β-cyclodextrin functionalised graphene nanosheets: a supramolecular based heterogeneous catalyst for C-C coupling reactions under green reaction conditions

Putta, Chandrababu; Sharavath, Vittal; Sarkar, Suprabhat; Ghosh, Sutapa

RSC Advances (2015), 5 (9), 6652-6660CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

The use of functional properties of native cyclodextrins in palladium nanoparticle-β-cyclodextrin-graphene nanosheet (Pd@CD-GNS) catalyzed carbon-carbon (C-C) coupling reactions have been investigated under green reaction conditions. The supramol. catalyst was prepd. by deposition of Pd nanoparticles (Pd NPs) on CD-GNS using ethanol as the greener solvent and in situ reducing agent. The catalytic activity of these catalysts is investigated in C-C coupling reactions such as Suzuki-Miyaura and Heck-Mizoroki reactions of aryl bromides 4-RC6H4Br (R = OH, t-Bu, NO2, etc.) and aryl chlorides R1Cl (R1 = C6H5, 4-HOC6H4, 2-pyridyl, etc.) with boronic acids R2B(OH)2 (R2 = C6H5, 4-O2NC6H4) and alkenes R3HC=CH2 [R3 = C(O)2H, C(O)2Me, C(O)2t-Bu, Ph] resp., under green reaction conditions i.e. in water, under phosphine free and aerobic conditions. This catalyst afforded excellent selectivities for the products in good to excellent yields under low Pd loadings (0.2-0.05 mol%), while ensuring the recovery and reusability of the catalysts. The CD supramol. mediators loaded on GNS act as stabilizing agents for the Pd NPs. The excellent catalytic activity of this system was attributed to the presence of CDs, excellent dispersibility in water, hydrophobic nature of the GNS support for the accumulation of org. substrates in water, "Breslow effect", the presence of PTC to overcome the mass transfer limitation onto the surface of GNS and formation of ternary CD/substrate/additive complexes on the Pd-GNS surface.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFehu7rI&md5=cbfee2b0031cf10cab50bbb4937b86a1
269
Ren, L.; Yang, F.; Wang, C. X.; Li, Y. F.; Liu, H. L.; Tu, Z. Q.; Zhang, L. Q.; Liu, Z. C.; Gao, J. S.; Xu, C. M. Plasma Synthesis of Oxidized Graphene Foam Supporting Pd Nanoparticles as a New Catalyst for One-Pot Synthesis of Dibenzyls RSC Adv. 2014, 4, 63048– 63054 DOI: 10.1039/C4RA11060A

Google Scholar

269
Plasma synthesis of oxidized graphene foam supporting Pd nanoparticles as a new catalyst for one-pot synthesis of dibenzyls

Ren, Liang; Yang, Fan; Wang, Chunxia; Li, Yongfeng; Liu, Hailing; Tu, Zhiqiang; Zhang, Liqiang; Liu, Zhichang; Gao, Jinsen; Xu, Chunming

RSC Advances (2014), 4 (108), 63048-63054CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

An environmentally-friendly method for the synthesis of Pd nanoparticle (Pd NPs) decorated different graphene supports has been developed, and the morphol. and structure of the hybrids are characterized by transmission electron microscopy, X-ray diffraction, XPS and elemental mappings. Four hybrid materials based on graphene foam (GF), oxidized graphene foam (OGF), graphene oxide (GO) and reduced graphene oxide (RGO) have been used to catalyze Heck coupling reactions, and the effect of support on the activity of the hybrid material has been studied. It was revealed that Pd NP decorated OGF (Pd/OGF) is the most active catalyst, showing better performance than the com. Pd/C catalyst. More importantly, the Pd/OGF catalyst has been successfully used for one-pot synthesis of dibenzyls RC6H4CH2CH2R1 [R = H, CH3, C(O)CH3, OCH3, Cl; R1 = C6H5, CO2CH2CH3] with different aryl bromides RC6H4Br and olefins CH2=CHR1, which has simplified the sepn. and purifn. process and realized a green org. synthesis process.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvF2lurrF&md5=e037183eeddefe0526e327f5d74ec87e
270
Fang, Y. X.; Wang, E. K. Electrochemical Biosensors on Platforms of Graphene Chem. Commun. 2013, 49, 9526– 9539 DOI: 10.1039/c3cc44735a

Google Scholar

270
Electrochemical biosensors on platforms of graphene

Fang, Youxing; Wang, Erkang

Chemical Communications (Cambridge, United Kingdom) (2013), 49 (83), 9526-9539CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)

A review. In recent years, graphene, the two-dimensional closely packed honeycomb carbon lattice, has been attracting much attention in the field of electrochem. due to its intrinsic properties and merits. Efforts to create novel graphene based electrochem. biosensors have led to the establishment of effective strategies for diverse bioassays, from simple mols. to complex biotargets. In this Feature Article, we provide an overview of electrochem. biosensing with graphene related materials, and discuss the role of graphene in different sensing protocols.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFWksLnL&md5=b92ceb429ffd2784bb296c943f4820dd
271
Wu, W.; Liu, Z. H.; Jauregui, L. A.; Yu, Q. K.; Pillai, R.; Cao, H. L.; Bao, J. M.; Chen, Y. P.; Pei, S. S. Wafer-Scale Synthesis of Graphene by Chemical Vapor Deposition and Its Application in Hydrogen Sensing Sens. Actuators, B 2010, 150, 296– 300 DOI: 10.1016/j.snb.2010.06.070

Google Scholar

271
Wafer-scale synthesis of graphene by chemical vapor deposition and its application in hydrogen sensing

Wu, Wei; Liu, Zhihong; Jauregui, Luis A.; Yu, Qingkai; Pillai, Rajeev; Cao, Helin; Bao, Jiming; Chen, Yong P.; Pei, Shin-Shem

Sensors and Actuators, B: Chemical (2010), 150 (1), 296-300CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)

Graphene with a large area was prepd. on Cu foils by chem. vapor deposition under ambient pressure. A 4'' × 4'' graphene film was transferred onto a 6'' Si wafer with a thermally grown oxide film. Raman mapping indicates monolayer graphene dominates the transferred graphene film. Gas sensors were fabricated on a 4 mm × 3 mm size graphene film with a 1 nm Pd film deposited for hydrogen detection. H2 in air with concns. in 0.0025-1% (25-10,000 ppm) was used to test graphene-based gas sensors. The gas sensors based on Pd-decorated graphene films show high sensitivity, fast response and recovery, and can be used with multiple cycles. The mechanism of hydrogen detection is also discussed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtFChsb%252FF&md5=a105f9dbbaeb01397d3d32344b9dc8ad
272
Li, M.; Bo, X. J.; Zhang, Y. F.; Han, C.; Guo, L. P. One-Pot Ionic Liquid-Assisted Synthesis of Highly Dispersed PtPd Nanoparticles/Reduced Graphene Oxide Composites for Nonenzymatic Glucose Detection Biosens. Bioelectron. 2014, 56, 223– 230 DOI: 10.1016/j.bios.2014.01.030

Google Scholar

272
One-pot ionic liquid-assisted synthesis of highly dispersed PtPd nanoparticles/reduced graphene oxide composites for nonenzymatic glucose detection

Li, Mian; Bo, Xiangjie; Zhang, Yufan; Han, Ce; Guo, Liping

Biosensors & Bioelectronics (2014), 56 (), 223-230CODEN: BBIOE4; ISSN:0956-5663. (Elsevier B.V.)

A series of highly dispersed bimetallic PtPd alloy nanoparticles (NPs) anchored on reduced graphene oxide (RGO) have been synthesized with the assistance of ionic liq. (IL: [VEIM]BF4). Different ratios of (PtCl6)2- and (PdCl4)2- ions were firstly attached to IL functionalized graphene oxide (GO) sheets in ethylene glycol (EG), and then the encased metal ions and graphene oxide sheets were reduced simultaneously by EG with the assistance of microwave. The characterization results of SEM (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), XPS, Raman spectroscopy, and X-ray diffraction (XRD) demonstrate that PtPd alloy NPs with small particle sizes are uniformly dispersed on RGO. Electrochem. measurements reveal that PtPd-IL-RGO modified electrode can directly catalyze glucose oxidn. and display enhanced current response compared with PtPd-RGO (such as: a response time within 3 s, a linear range from 0.1 to 22 mM at 0 V, good reproducibility, considerable stability, and excellent anti-interference to electroactive mols. and Cl-). The superior catalytic activity and selectivity make PtPd-IL-RGO nanomaterials very promising for applications in direct detection of glucose.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjsVajsLo%253D&md5=9f05ded8ade2b47585848222dc183fea
273
Mukherji, A.; Seger, B.; Lu, G. Q.; Wang, L. Z. Nitrogen Doped Sr₂Ta₂O₇ Coupled with Graphene Sheets as Photocatalysts for Increased Photocatalytic Hydrogen Production ACS Nano 2011, 5, 3483– 3492 DOI: 10.1021/nn102469e

Google Scholar

273
Nitrogen Doped Sr2Ta2O7 Coupled with Graphene Sheets as Photocatalysts for Increased Photocatalytic Hydrogen Production

Mukherji, Aniruddh; Seger, Brian; Lu, Gao Qing; Wang, Lianzhou

ACS Nano (2011), 5 (5), 3483-3492CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

In this work we present the synthesis of a new type of N-doped tantalate, Sr2Ta2O7-xNx, which exhibited significantly increased visible light absorption and improved photocatalytic H prodn. by 87% under solar irradn., compared with its undoped counterpart Sr2Ta2O7. The photocatalyst also exhibited a strong capability in photoinduced redn. of exfoliated graphene oxide (GO) to graphene sheets. By using graphene as a support for a Pt cocatalyst, a new type of composite contg. graphene-Pt and Sr2Ta2O7-xNx was designed, which demonstrated an addnl. ∼80% increase in H prodn. and an quantum efficiency of 6.45% (∼177% increase from pristine undoped Sr2Ta2O7) due to the efficient charge carrier sepn. on the photocatalyst. Probably graphene can play an important role as an electron transfer highway, which facilitates the charge carrier collection onto Pt co-catalysts. The method can thus be considered as an excellent strategy to increase photocatalytic H prodn. in addn. to a commonly applied doping method.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXkvVOqtb8%253D&md5=f405bbb5e72bc6a14135299a8951f934
274
Li, Q.; Guo, B. D.; Yu, J. G.; Ran, J. R.; Zhang, B. H.; Yan, H. J.; Gong, J. R. Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Production of CdS-Cluster-Decorated Graphene Nanosheets J. Am. Chem. Soc. 2011, 133, 10878– 10884 DOI: 10.1021/ja2025454

Google Scholar

274
Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Production of CdS-Cluster-Decorated Graphene Nanosheets

Li, Qin; Guo, Beidou; Yu, Jiaguo; Ran, Jingrun; Zhang, Baohong; Yan, Huijuan; Gong, Jian Ru

Journal of the American Chemical Society (2011), 133 (28), 10878-10884CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

The prodn. of clean and renewable H through H2O splitting using photocatalysts has received much attention due to the increasing global energy crises. A high efficiency of the photocatalytic H2 prodn. was achieved using graphene nanosheets decorated with CdS clusters as visible-light-driven photocatalysts. The materials were prepd. by a solvothermal method in which graphene oxide (GO) served as the support and Cd acetate (Cd(Ac)2) as the CdS precursor. These nanosized composites reach a high H2-prodn. rate of 1.12 mmol h-1 (∼4.87 times higher than that of pure CdS nanoparticles) at graphene content of 1.0% and Pt 0.5% under visible-light irradn. and an apparent quantum efficiency (QE) of 22.5% at wavelength of 420 nm. This high photocatalytic H2-prodn. activity is attributed predominantly to the presence of graphene, which serves as an electron collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carriers from CdS nanoparticles. This work highlights the potential application of graphene-based materials in the field of energy conversion.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXnvFahu78%253D&md5=56a74c1ff602be77bf55bd04f961eb71
275
Meng, F. K.; Li, J. T.; Cushing, S. K.; Zhi, M. J.; Wu, N. Q. Solar Hydrogen Generation by Nanoscale p-n Junction of p-type Molybdenum Disulfide/n-type Nitrogen-Doped Reduced Graphene Oxide J. Am. Chem. Soc. 2013, 135, 10286– 10289 DOI: 10.1021/ja404851s

Google Scholar

275
Solar Hydrogen Generation by Nanoscale p-n Junction of p-type Molybdenum Disulfide/n-type Nitrogen-Doped Reduced Graphene Oxide

Meng, Fanke; Li, Jiangtian; Cushing, Scott K.; Zhi, Mingjia; Wu, Nianqiang

Journal of the American Chemical Society (2013), 135 (28), 10286-10289CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

Molybdenum disulfide (MoS2) is a promising candidate for solar hydrogen generation but it alone has negligible photocatalytic activity. 5-20 Nm sized p-type MoS2 nanoplatelets are deposited on the n-type nitrogen-doped reduced graphene oxide (n-rGO) nanosheets to form multiple nanoscale p-n junctions in each rGO nanosheet. The p-MoS2/n-rGO heterostructure shows significant photocatalytic activity toward the hydrogen evolution reaction (HER) in the wavelength range from the UV light through the near-IR light. The photoelectrochem. measurement shows that the p-MoS2/n-rGO junction greatly enhances the charge generation and suppresses the charge recombination, which is responsible for enhancement of solar hydrogen generation. The p-MoS2/n-rGO is an earth-abundant and environmentally benign photocatalyst for solar hydrogen generation.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtValsbbM&md5=f897a91942a5538557e2b1c28d3a9211
276
Wang, Y.; Yu, J. G.; Xiao, W.; Li, Q. Microwave-Assisted Hydrothermal Synthesis of Graphene Based Au-TiO₂ Photocatalysts for Efficient Visible-Light Hydrogen Production J. Mater. Chem. A 2014, 2, 3847– 3855 DOI: 10.1039/c3ta14908k

Google Scholar

276
Microwave-assisted hydrothermal synthesis of graphene based Au-TiO2 photocatalysts for efficient visible-light hydrogen production

Wang, Ying; Yu, Jiaguo; Xiao, Wei; Li, Qin

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (11), 3847-3855CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

The construction and application of visible-light-driven photocatalysts falls in the central focus for the efficient utilization of renewable solar energy, which provides unprecedented opportunities for addressing the increasing concerns on energy and environmental sustainability. Herein, graphene based Au-TiO2 photocatalysts were fabricated by a simple, one-step microwave-assisted hydrothermal method, using Degussa P25 TiO2 powder (P25), graphene oxide and HAuCl4 aq. soln. as the raw materials. The effects of graphene introduction and gold loading on the photocatalytic hydrogen prodn. rates of the as-prepd. samples in a methanolic aq. soln. were investigated. The results indicated that Au-TiO2-graphene composite had a significantly increased visible light absorption and enhanced photocatalytic H2-prodn. activity compared to the Au-TiO2 composite. In comparison, the pure TiO2, graphene-TiO2 and graphene-Au had no appreciable visible-light-driven H2 prodn. The enhanced photocatalytic H2-prodn. activity of the Au-TiO2-graphene composite is ascribed to (1) the load of the Au nanoparticles which broadens the visible light response of TiO2 due to the surface plasmon resonance (SPR) effect, and (2) the introduction of graphene, which functions as rapid electron transfer units, facilitating the space sepn. of photoelectron and hole pairs. The proposed H2-prodn. activity enhancement mechanism was further confirmed by the transient photocurrent response and electrochem. impedance spectroscopy (EIS) expts.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXislGktbg%253D&md5=b911623920e65817522c05bdb00155b9
277
Martin, S. T.; Lee, A. T.; Hoffmann, M. R. Chemical Mechanism of Inorganic Oxidants in the Process – Increased Rates of Degradation of Chlorinated Hydrocarbons Environ. Sci. Technol. 1995, 29, 2567– 2573 DOI: 10.1021/es00010a017

Google Scholar

There is no corresponding record for this reference.
278
Vinayan, B. P.; Nagar, R.; Ramaprabhu, S. Solar Light Assisted Green Synthesis of Palladium Nanoparticle Decorated Nitrogen Doped Graphene for Hydrogen Storage Application J. Mater. Chem. A 2013, 1, 11192– 11199 DOI: 10.1039/c3ta12016c

Google Scholar

278
Solar light assisted green synthesis of palladium nanoparticle decorated nitrogen doped graphene for hydrogen storage application

Vinayan, B. P.; Nagar, Rupali; Ramaprabhu, S.

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2013), 1 (37), 11192-11199CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Recent research developments reveal that nanomaterials, esp. C nanomaterials, can play a significant role in the performance enhancement of energy conversion and storage devices. The synthesis procedure of nanomaterials, however, remains one of the governing factors for their wide scale implementation. An in situ synthesis method to prep. Pd nanoparticle decorated N doped graphene sheets (Pd/N-SG) using focused solar radiation is developed. The present synthesis technique combines 3 processes simultaneously, (a) graphene sheet formation, (b) N doping of graphene sheets and (c) metal precursor redn. to metal nanoparticles, in one step through a green approach. The H storage properties of the Pd/N-SG sample are studied using high pressure Sievert's app. and the sample exhibits an excellent H storage capacity of 4.3% at room temp. (25° and 4 MPa H pressure). The method developed for the synthesis is environmentally benign, easy to adopt and economical. Also, the proposed 1-step synthesis method can be easily scaled up to large quantities and this opens a new pathway for the synthesis of nanomaterials for use in the renewable energy field.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtlClsb7E&md5=3649f8f7f1292bb0cd47cbb2bbda4b47
279
Tuček, J.; Kemp, K. C.; Kim, K. S.; Zbořil, R. Iron-Oxide-Supported Nanocarbon in Lithium-Ion Batteries, Medical, Catalytic, and Environmental Applications ACS Nano 2014, 8, 7571– 7612 DOI: 10.1021/nn501836x

Google Scholar

279
Iron-Oxide-Supported Nanocarbon in Lithium-Ion Batteries, Medical, Catalytic, and Environmental Applications

Tucek, Jiri; Kemp, Kingsley Christian; Kim, Kwang Soo; Zboril, Radek

ACS Nano (2014), 8 (8), 7571-7612CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

A review. Owing to the three different orbital hybridizations carbon can adopt, the existence of various carbon nanoallotropes differing also in dimensionality has been already affirmed with other structures predicted and expected to emerge in the future. Despite numerous unique features and applications of 2D graphene, 1D carbon nanotubes, or 0D fullerenes, nanodiamonds, and carbon quantum dots, which have been already heavily explored, any of the existing carbon allotropes do not offer competitive magnetic properties. For challenging applications, carbon nanoallotropes are functionalized with magnetic species, esp. of iron oxide nature, due to their interesting magnetic properties (superparamagnetism and strong magnetic response under external magnetic fields), easy availability, biocompatibility, and low cost. In addn., combination of iron oxides (magnetite, maghemite, hematite) and carbon nanostructures brings enhanced electrochem. performance and (photo)catalytic capability due to synergetic and cooperative effects. This work aims at reviewing these advanced applications of iron-oxide-supported nanocarbon composites where iron oxides play a diverse role. Various architectures of carbon/iron oxide nanocomposites, their synthetic procedures, physicochem. properties, and applications are discussed in details. A special attention is devoted to hybrids of carbon nanotubes and rare forms (mesoporous carbon, nanofoam) with magnetic iron oxide carriers for advanced environmental technologies. The review also covers the huge application potential of graphene/iron oxide nanocomposites in the field of energy storage, biomedicine, and remediation of environment. Among various discussed medical applications, magnetic composites of zero-dimensional fullerenes and carbon dots are emphasized as promising candidates for complex theranostics and dual magneto-fluorescence imaging.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFSrt7rJ&md5=b89bf42e7f5be8af877cdcc36bc5450c
280
Kucinskis, G.; Bajars, G.; Kleperis, J. Graphene in Lithium Ion Battery Cathode Materials: A Review J. Power Sources 2013, 240, 66– 79 DOI: 10.1016/j.jpowsour.2013.03.160

Google Scholar

280
Graphene in lithium ion battery cathode materials: A review

Kucinskis, Gints; Bajars, Gunars; Kleperis, Janis

Journal of Power Sources (2013), 240 (), 66-79CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)

A review. Graphene is a relatively new and promising material, displaying a unique array of phys. and chem. properties. Although considered to be esp. promising for the use in energy storage applications, graphene has only recently been implemented as an electron conducting additive for lithium ion battery cathode materials. In current studies graphene is found to significantly improve cathode electrochem. performance. As the charge capacity, rate capability and cyclability of lithium ion batteries are still in ever-remaining need of improvement, this article examines the prospects of graphene implementation into lithium ion battery cathodes to meet such demands. The existing literature and recent advances on the topic have been reviewed, covering the prepn. of graphene and graphene composite lithium ion battery cathodes, their structure and electrochem. properties along with underlying principles for electrochem. performance enhancement of such materials.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtFKntLnO&md5=d1f4c2f6d6c131dbd50a9fb4a5d8e835
281
Sun, W. W.; Wang, Y. Graphene-Based Nanocomposite Anodes for Lithium-Ion Batteries Nanoscale 2014, 6, 11528– 11552 DOI: 10.1039/C4NR02999B

Google Scholar

There is no corresponding record for this reference.
282
Yang, Q.; Liang, Q.; Liu, J.; Liang, S. Q.; Tang, S. S.; Lu, P. J.; Lu, Y. K. Ultrafine MoO₂ Nanoparticles Grown on Graphene Sheets as Anode Materials for Lithium-Ion Batteries Mater. Lett. 2014, 127, 32– 35 DOI: 10.1016/j.matlet.2014.03.055

Google Scholar

282
Ultrafine MoO2 nanoparticles grown on graphene sheets as anode materials for lithium-ion batteries

Yang, Qian; Liang, Qiang; Liu, Jun; Liang, Shuquan; Tang, Shasha; Lu, Peijie; Lu, Yakun

Materials Letters (2014), 127 (), 32-35CODEN: MLETDJ; ISSN:0167-577X. (Elsevier B.V.)

We have successfully synthesized ultrafine MoO2 nanoparticles with the diam. of ∼5 nm grown on graphene sheets through a facile hydrothermal process which only involves com. MoO3, ethylene glycol and GO as starting materials. More importantly, the ultrafine MoO2 nanoparticle/graphene hybrids exhibit great electrochem. performances with reversible lithium storage capacity as high as 765.3 mA h g-1 after 40 cycles, as anode materials for lithium ion batteries.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXosVajsbg%253D&md5=bc4b489036f1993428c9b54c721ffcf9
283
Pan, L.; Zhu, X.-D.; Xie, X.-M.; Liu, Y.-T. Smart Hybridization of TiO₂ Nanorods and Fe₃O₄ Nanoparticles with Pristine Graphene Nanosheets: Hierarchically Nanoengineered Ternary Heterostructures for High-Rate Lithium Storage Adv. Funct. Mater. 2015, 25, 3341– 3350 DOI: 10.1002/adfm.201404348

Google Scholar

283
Smart Hybridization of TiO2 Nanorods and Fe3O4 Nanoparticles with Pristine Graphene Nanosheets: Hierarchically Nanoengineered Ternary Heterostructures for High-Rate Lithium Storage

Pan, Long; Zhu, Xiao-Dong; Xie, Xu-Ming; Liu, Yi-Tao

Advanced Functional Materials (2015), 25 (22), 3341-3350CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

Today, the ever-increasing demand for large-size power tools has provoked worldwide competition in developing lithium-ion batteries having higher energy and power densities. In this context, advanced anode materials are being extensively pursued, among which TiO2 is particularly promising owing to its high safety, excellent cost and environmental performances, and high cycle stability. However, TiO2 is faced with two detrimental deficiencies, i.e., extremely low theor. capacity and cond. Herein, a smart hybridization strategy is proposed for the hierarchical co-assembly of TiO2 nanorods and Fe3O4 nanoparticles on pristine graphene nanosheets, aiming to simultaneously address the capacity and cond. deficiencies of TiO2 by coupling it with high-capacity (Fe3O4) and high-cond. (pristine graphene) components. The resulting novel, multifunctional ternary heterostructures effectively integrate the intriguing functionalities of the three building blocks: TiO2 as the major active material can adequately retain such merits as high safety and cycle stability, Fe3O4 as the auxiliary active material can contribute extraordinarily high capacities, and pristine graphene as the conductive dopant can guarantee sufficient percolation pathways. Benefiting from a remarkable synergy, the ternary heterostructures deliver superior reversible capacities and rate capabilities, thus casting new light on developing next-generation, high-performance anode materials.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmslensrc%253D&md5=a6721b934319412a72c479a98e1fdbd8
284
Kasavajjula, U.; Wang, C. S.; Appleby, A. J. Nano- and Bulk-Silicon-Based Insertion Anodes for Lithium-Ion Secondary Cells J. Power Sources 2007, 163, 1003– 1039 DOI: 10.1016/j.jpowsour.2006.09.084

Google Scholar

284
Nano- and bulk-silicon-based insertion anodes for lithium-ion secondary cells

Kasavajjula, Uday; Wang, Chunsheng; Appleby, A. John

Journal of Power Sources (2007), 163 (2), 1003-1039CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)

A review. The increase in energy d. and power d. requirements for lithium-ion batteries for com. applications has led to a search for higher capacity electrode materials than those available today. Silicon would seem to be a possible alternative for the graphite or carbon anode because its intercalation capacity is the highest known. However, the large capacity fade obsd. during initial cycling has prevented the silicon anode from being commercialized. Methodologies adopted for reducing the capacity fade obsd. in silicon-based anodes are summarized. The challenges that remain in using silicon and silicon-based anodes are discussed and possible approaches for overcoming them are proposed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XhtlCmtLfP&md5=faa41b0a05b78cd9312c5386e4952a39
285
Zhu, S. M.; Zhu, C. L.; Ma, J.; Meng, Q.; Guo, Z. P.; Yu, Z. Y.; Lu, T.; Li, Y.; Zhang, D.; Lau, W. M. Controlled Fabrication of Si Nanoparticles on Graphene Sheets for Li-Ion Batteries RSC Adv. 2013, 3, 6141– 6146 DOI: 10.1039/c3ra22989k

Google Scholar

285
Controlled fabrication of Si nanoparticles on graphene sheets for Li-ion batteries

Zhu, Shenmin; Zhu, Chengling; Ma, Jun; Meng, Qing; Guo, Zaiping; Yu, Ziyong; Lu, Tao; Li, Yao; Zhang, Di; Lau, Woon Ming

RSC Advances (2013), 3 (17), 6141-6146CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

A new route is presented for the synthesis of Si nanoparticle/Graphene (Si-Gr) composite by a sonochem. method and then magnesiothermic redn. process. During the process, silica particles were firstly synthesized and deposited on the surface of graphene oxide (SiO2-GO) by ultrasonic waves, subsequent low-temp. magnesiothermic redn. transformed SiO2 to Si nanoparticles in situ on graphene sheets. The phase of the obtained materials was influenced by the wt. ratio of Mg to SiO2-GO. With the optimized ratio of 1 : 1, we can get Si nanoparticles on Gr sheets, with the av. particle size of Si around 30 nm. Accordingly, the resultant Si-Gr with 78 wt% Si inside delivered a reversible capacity of 1100 mA h g-1, with very little fading when the charge rates change from 100 mA g-1 to 2000 mA g-1 and then back to 100 mA g-1. Thus, this strategy offers an efficient method for the controlled synthesis of Si nanoparticles on Gr sheets with a high rate performance, attributing to combination of the nanosized Si particles and the graphene.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXltVyju7w%253D&md5=ff3973ef4ba94bcc9493fe7af4195737
286
Hassan, F. M.; Elsayed, A. R.; Chabot, V.; Batmaz, R.; Xiao, X. C.; Chen, Z. W. Subeutectic Growth of Single-Crystal Silicon Nanowires Grown on and Wrapped with Graphene Nanosheets: High-Performance Anode Material for Lithium-Ion Battery ACS Appl. Mater. Interfaces 2014, 6, 13757– 13764 DOI: 10.1021/am5032067

Google Scholar

286
Subeutectic Growth of Single-Crystal Silicon Nanowires Grown on, and Wrapped with, Graphene Nanosheets: High-Performance Anode Material for Lithium-Ion Battery

Hassan, Fathy M.; Elsayed, Abdel Rahman; Chabot, Victor; Batmaz, Rasim; Xiao, Xingcheng; Chen, Zhongwei

ACS Applied Materials & Interfaces (2014), 6 (16), 13757-13764CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

A novel one-pot synthesis for the subeutectic growth of (111) oriented Si nanowires on an in situ formed nickel nanoparticle catalyst prepd. from an inexpensive nickel nitrate precursor is developed. Addnl., anchoring the nickel nanoparticles to a simultaneously reduced graphene oxide support created synergy between the individual components of the c-SiNW-G composite, which greatly improved the reversible charge capacity and it is retention at high c.d. when applied as an anode for a lithium-ion battery. The c-SiNW-G electrodes for Li-ion battery achieved excellent high-rate performance, producing a stable reversible capacity of 550 mAh g-1 after 100 cycles at 6.8 A g-1 (78% of that at 0.1 A g-1). Thus, with further development this process creates an important building block for a new wave of low-cost silicon nanowire materials and a promising avenue for high rate Li-ion batteries.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1GlurvE&md5=9130d0da641345be874f6b7a6389124b
287
Zhou, M.; Li, X.; Wang, B.; Zhang, Y.; Ning, J.; Xiao, Z.; Zhang, X.; Chang, Y.; Zhi, L. High-Performance Silicon Battery Anodes Enabled by Engineering Graphene Assemblies Nano Lett. 2015, 15, 6222– 6228 DOI: 10.1021/acs.nanolett.5b02697

Google Scholar

287
High-Performance Silicon Battery Anodes Enabled by Engineering Graphene Assemblies

Zhou, Min; Li, Xianglong; Wang, Bin; Zhang, Yunbo; Ning, Jing; Xiao, Zhichang; Zhang, Xinghao; Chang, Yanhong; Zhi, Linjie

Nano Letters (2015), 15 (9), 6222-6228CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

A novel material/electrode design formula is proposed and an engineered self-supporting electrode configuration, namely, silicon nanoparticle impregnated assemblies of templated carbon-bridged oriented graphene is developed. Their use is demonstrated as binder-free lithium-ion battery anodes with exceptional lithium storage performances, simultaneously attaining high gravimetric capacity (1390 mAh g-1 at 2 A g-1 with respect to the total electrode wt.), high volumetric capacity (1807 mAh cm-3 that is more than three times that of graphite anodes), remarkable rate capability (900 mAh g-1 at 8 A g-1), excellent cyclic stability (0.025% decay per cycle over 200 cycles), and competing areal capacity (as high as 4 and 6 mAh cm-2 at 15 and 3 mA cm-2, resp.). Such combined level of performance is attributed to the templated carbon bridged oriented graphene assemblies involved. This engineered graphene bulk assemblies not only create a robust bicontinuous network for rapid transport of both electrons and lithium ions throughout the electrode even at high material mass loading but also allow achieving a substantially high material tap d. (1.3 g cm-3). Coupled with a simple and flexible fabrication protocol as well as practically scalable raw materials (e.g., silicon nanoparticles and graphene oxide), the material/electrode design developed would propagate new and viable battery material/electrode design principles and opportunities for energy storage systems with high-energy and high-power characteristics.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtlymsLzN&md5=f4d16ca1876519270ab2abe403f513b9
288
Yuan, F. W.; Tuan, H. Y. Scalable Solution-Grown High-Germanium-Nanoparticle-Loading Graphene Nanocomposites as High-Performance Lithium-Ion Battery Electrodes: An Example of a Graphene-Based Platform toward Practical Full-Cell Applications Chem. Mater. 2014, 26, 2172– 2179 DOI: 10.1021/cm5002016

Google Scholar

288
Scalable solution-grown high-germanium-nanoparticle-loading graphene nanocomposites as high-performance lithium-ion battery electrodes: an example of a graphene-based platform toward practical full-cell applications

Yuan, Fang-Wei; Tuan, Hsing-Yu

Chemistry of Materials (2014), 26 (6), 2172-2179CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)

Graphene in the form of graphene/nanocrystal nanocomposites can improve the electrochem. performance of nanocrystals for lithium-ion (Li-ion) battery anodes, which is esp. important for high-capacity Li-alloy materials such as Si and Ge. For practical full-cell applications, graphene composite electrodes consisting of a large portion of active materials (i.e., a surface of graphene sheets evenly distributed with dense nanoparticles) are required. We have developed a facile soln.-based method to synthesize subgram quantities of nanocomposites composed of reduced graphene oxide (RGO) sheets covered with a high concn. (∼80 wt %) of single-crystal 4.90(±0.80) nm diam. Ge nanoparticles. Subsequently, carbon-coated Ge nanoparticles/RGO (Ge/RGO/C) sandwich structures were formed via a carbonization process. The high-nanoparticle-loading nanocomposites exhibited superior Li-ion battery anode performance when examd. with a series of comprehensive tests, such as receiving a practical capacity of Ge (1332 mAh/g) close (96.2%) to its theor. value (1384 mAh/g) when cycled at a 0.2 C rate and having a high-rate capability over hundreds of cycles. Furthermore, the performance of the full cells assembled using a Ge/RGO/C anode and an LiCoO2 cathode were evaluated. The cells were able to power a wide range of electronic devices, including an light-emitting-diode (LED) array consisting of over 150 bulbs, blue LED arrays, a scrolling LED marquee, and an elec. fan. Thus, this study demonstrates a proof of concept of the use of graphene-based nanocomposites toward practical Li-ion battery applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXisFahu74%253D&md5=1ccd04d62b1441d8e276c0e1cf44253a
289
Zhang, H. W.; Zhou, L.; Noonan, O.; Martin, D. J.; Whittaker, A. K.; Yu, C. Z. Tailoring the Void Size of Iron Oxide@Carbon Yolk-Shell Structure for Optimized Lithium Storage Adv. Funct. Mater. 2014, 24, 4337– 4342 DOI: 10.1002/adfm.201400178

Google Scholar

289
Tailoring the Void Size of Iron Oxide@Carbon Yolk-Shell Structure for Optimized Lithium Storage

Zhang, Hongwei; Zhou, Liang; Noonan, Owen; Martin, Darren J.; Whittaker, Andrew K.; Yu, Chengzhong

Advanced Functional Materials (2014), 24 (27), 4337-4342CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

High-capacity lithium-ion battery anode materials, such as transition metal oxides, Sn and Si, suffer from large vol. expansion during lithiation, which causes capacity decay. Introducing sufficient void space to accommodate the vol. change is essential to achieve prolonged cycling stability. However, excessive void space may significantly compromise the volumetric energy d. Herein, a method to control the void size in iron oxide@carbon (FeOx@C) yolk-shell structures is developed and the relationship between the void space and electrochem. performance is demonstrated. With an optimized void size, the FeOx@C yolk-shell structure exhibits the best cycling performance. A high reversible capacity of ≈810 mA-h/g is obtained at 0.2C, maintaining 790 mA-h/g after 100 cycles. This contrasts with FeOx@C materials having either smaller or larger void sizes, in which significant capacity fading is obsd. during cycling. This contribution provides an effective approach to alleviate the vol. expansion problem, which can be generally applied to other anode materials to improve their performance in lithium-ion batteries.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXlsFyjsbc%253D&md5=1972345626f474d2b3ebb573a4a81d85
290
Li, Y.; Zhu, C. L.; Lu, T.; Guo, Z. P.; Zhang, D.; Ma, J.; Zhu, S. M. Simple Fabrication of a Fe₂O₃/Carbon Composite for Use in a High-Performance Lithium Ion Battery Carbon 2013, 52, 565– 573 DOI: 10.1016/j.carbon.2012.10.015

Google Scholar

290
Simple fabrication of a Fe2O3/carbon composite for use in a high-performance lithium ion battery

Li, Yao; Zhu, Chengling; Lu, Tao; Guo, Zaiping; Zhang, Di; Ma, Jun; Zhu, Shenmin

Carbon (2013), 52 (), 565-573CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

A simple approach was developed for the fabrication of a Fe2O3/carbon composite by impregnating activated carbon with a ferric nitrate soln. and calcining it. The composite contains graphitic layers and 10 wt.% Fe2O3 particles of 20-50 nm in diam. The composite has a high sp. surface area of ∼828 m2 g-1 and when used as the anode in a lithium ion battery (LIB), it showed a reversible capacity of 623 mAh g-1 for the first 100 cycles at 50 mA g-1. A discharge capacity higher than 450 mAh g-1 at 1000 mA g-1 was recorded in rate performance testing. This highly improved reversible capacity and rate performance is attributed to the combination of (i) the formation of graphitic layers in the composite, which possibly improves the matrix elec. cond., (ii) the interconnected porous channels whose diams. ranges from the macro- to meso- pore, which increases lithium-ion mobility, and (iii) the Fe2O3 nanoparticles that facilitate the transport of electrons and shorten the distance for Li+ diffusion. This study provides a cost-effective, highly efficient means to fabricate materials which combine conducting carbon with nanoparticles of metal or metal oxide for the development of a high-performance LIB.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1elsbrL&md5=50e8a827c5d6028805d1bdd4ad859533
291
Slater, M. D.; Kim, D.; Lee, E.; Johnson, C. S. Sodium-Ion Batteries Adv. Funct. Mater. 2013, 23, 947– 958 DOI: 10.1002/adfm.201200691

Google Scholar

291
Sodium-Ion Batteries

Slater, Michael D.; Kim, Donghan; Lee, Eungje; Doeff, Marca; Johnson, Christopher S.

Advanced Functional Materials (2013), 23 (8), 947-958CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

A review. The status of ambient temp. sodium ion batteries is reviewed in light of recent developments in anode, electrolyte and cathode materials. These devices, although early in their stage of development, are promising for large-scale grid storage applications due to the abundance and very low cost of sodium-contg. precursors used to make the components. The engineering knowledge developed recently for highly successful Li ion batteries can be leveraged to ensure rapid progress in this area, although different electrode materials and electrolytes will be required for dual intercalation systems based on sodium. In particular, new anode materials need to be identified, since the graphite anode, commonly used in lithium systems, does not intercalate sodium to any appreciable extent. A wider array of choices is available for cathodes, including high performance layered transition metal oxides and polyanionic compds. Recent developments in electrodes are encouraging, but a great deal of research is necessary, particularly in new electrolytes, and the understanding of the SEI films. The engineering modeling calcns. of Na-ion battery energy d. indicate that 210 Wh kg-1 in gravimetric energy is possible for Na-ion batteries compared to existing Li-ion technol. if a cathode capacity of 200 mAh g-1 and a 500 mAh g-1 anode can be discovered with an av. cell potential of 3.3 V.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XntlSnurc%253D&md5=fa5d7d089d261a40896cb6b03e88bfbe
292
Yu, D. Y. W.; Prikhodchenko, P. V.; Mason, C. W.; Batabyal, S. K.; Gun, J.; Sladkevich, S.; Medvedev, A. G.; Lev, O. High-Capacity Antimony Sulphide Nanoparticle-Decorated Graphene Composite as Anode for Sodium-Ion Batteries Nat. Commun. 2013, 4, 2922 DOI: 10.1038/ncomms3922

Google Scholar

292
High-capacity antimony sulphide nanoparticle-decorated graphene composite as anode for sodium-ion batteries

Yu Denis Y W; Prikhodchenko Petr V; Mason Chad W; Batabyal Sudip K; Gun Jenny; Sladkevich Sergey; Medvedev Alexander G; Lev Ovadia

Nature communications (2013), 4 (), 2922 ISSN:.

Sodium-ion batteries are an alternative to lithium-ion batteries for large-scale applications. However, low capacity and poor rate capability of existing anodes are the main bottlenecks to future developments. Here we report a uniform coating of antimony sulphide (stibnite) on graphene, fabricated by a solution-based synthesis technique, as the anode material for sodium-ion batteries. It gives a high capacity of 730 mAh g(-1) at 50 mA g(-1), an excellent rate capability up to 6C and a good cycle performance. The promising performance is attributed to fast sodium ion diffusion from the small nanoparticles, and good electrical transport from the intimate contact between the active material and graphene, which also provides a template for anchoring the nanoparticles. We also demonstrate a battery with the stibnite-graphene composite that is free from sodium metal, having energy density up to 80 Wh kg(-1). The energy density could exceed that of some lithium-ion batteries with further optimization.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2c3ltFajuw%253D%253D&md5=00d6ac79468675541d9951b7cfb704e0
293
Xiao, Z. B.; Yang, Z.; Wang, L.; Nie, H. G.; Zhong, M. E.; Lai, Q. Q.; Xu, X. J.; Zhang, L. J.; Huang, S. M. A Lightweight TiO₂/Graphene Interlayer, Applied as a Highly Effective Polysulfide Absorbent for Fast, Long-Life Lithium-Sulfur Batteries Adv. Mater. 2015, 27, 2891– 2898 DOI: 10.1002/adma.201405637

Google Scholar

293
A Lightweight TiO2/Graphene Interlayer, Applied as a Highly Effective Polysulfide Absorbent for Fast, Long-Life Lithium-Sulfur Batteries

Xiao, Zhubing; Yang, Zhi; Wang, Lu; Nie, Huagui; Zhong, Mei-e; Lai, Qianqian; Xu, Xiangju; Zhang, Lijie; Huang, Shaoming

Advanced Materials (Weinheim, Germany) (2015), 27 (18), 2891-2898CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

An integrated selective interlayer was obtained by coating the surface of a C-S battery cathode with a com. graphene-TiO2 film, which accounted for 7.8 wt.% of the entire cathode. The porous graphene afforded an addnl. elec. conductive network and phys. trapped sulfide and polysulfides. The TiO2 in the barrier film further chem. suppressed the dissoln. of polysulfides and alleviated the undesirable shuttle effect. The porous CNT-S cathode coated with the graphene-TiO2 film delivered a reversible specific capacity of 1040 mA-h/g over 300 cycles at 0.5 C, with ultralow capacity degrdn. rates of 0.01% and 0.018% per cycle at 2 and 3 C, resp., over 1000 cycles.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsVKnu7g%253D&md5=1189dc748af9ad475339df2976b10a41
294
Ryu, W. H.; Yoon, T. H.; Song, S. H.; Jeon, S.; Park, Y. J.; Kim, I. D. Bifunctional Composite Catalysts Using Co₃O₄ Nanofibers Immobilized on Nonoxidized Graphene Nanoflakes for High-Capacity and Long-Cycle Li-O₂ Batteries Nano Lett. 2013, 13, 4190– 4197 DOI: 10.1021/nl401868q

Google Scholar

294
Bifunctional Composite Catalysts Using Co3O4 Nanofibers Immobilized on Non-oxidized Graphene Nanoflakes for High-Capacity and Long-Cycle Li-O2 Batteries

Ryu, Won-Hee; Yoon, Taek-Han; Song, Sung Ho; Jeon, Seokwoo; Park, Yong-Joon; Kim, Il-Doo

Nano Letters (2013), 13 (9), 4190-4197CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Designing a highly efficient catalyst is essential to improve the electrochem. performance of Li-O2 batteries for long-term cycling. Also, these batteries often show significant capacity fading due to the irreversible reaction characteristics of the Li2O2 product. To overcome these limitations, the authors propose a bifunctional composite catalyst composed of electrospun 1-dimensional (1D) Co3O4 nanofibers (NFs) immobilized on both sides of the 2-dimensional nonoxidized graphene nanoflakes (GNFs) for an O electrode in Li-O2 batteries. Highly conductive GNFs with non-covalent functionalization can facilitate a homogeneous dispersion in soln., thereby enabling simple and uniform attachment of 1-dimensional Co3O4 NFs on GNFs without re-stacking. High 1st discharge capacity of 10,500 mA-h/g and superior cyclability for 80 cycles with a limited capacity of 1000 mA-h/g were achieved by (i) improved catalytic activity of 1-dimensional Co3O4 NFs with large surface area, (ii) facile electron transport via interconnected GNFs functionalized by Co3O4 NFs, and (iii) fast O2 diffusion through the ultrathin GNF layer and porous Co3O4 NF networks.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht1arsrvI&md5=2b9cbe928ddead4fddfe284ff568d6e5
295
Chandra, V.; Park, J.; Chun, Y.; Lee, J. W.; Hwang, I.-C.; Kim, K. S. Water Dispersible Magnetite-Reduced Graphene Oxide Composites for Arsenic Removal ACS Nano 2010, 4, 3979– 3986 DOI: 10.1021/nn1008897

Google Scholar

There is no corresponding record for this reference.
296
Hu, Y.; Jensen, J. O.; Zhang, W.; Huang, Y. J.; Cleemann, L. N.; Xing, W.; Bjerrum, N. J.; Li, Q. F. Direct Synthesis of Fe₃C-Functionalized Graphene by High Temperature Autoclave Pyrolysis for Oxygen Reduction ChemSusChem 2014, 7, 2099– 2103 DOI: 10.1002/cssc.201402183

Google Scholar

296
Direct Synthesis of Fe3C-Functionalized Graphene by High Temperature Autoclave Pyrolysis for Oxygen Reduction

Hu, Yang; Jensen, Jens Oluf; Zhang, Wei; Huang, Yunjie; Cleemann, Lars N.; Xing, Wei; Bjerrum, Niels J.; Li, Qingfeng

ChemSusChem (2014), 7 (8), 2099-2103CODEN: CHEMIZ; ISSN:1864-5631. (Wiley-VCH Verlag GmbH & Co. KGaA)

A novel approach is presented to direct fabrication of few-layer graphene sheets with encapsulated Fe3C nanoparticles from pyrolysis of volatile non-graphitic precursors without any substrate. This one-step autoclave approach is facile and potentially scalable for prodn. Tested as an electrocatalyst, the graphene-based composite exhibited excellent catalytic activity towards the oxygen redn. reaction in alk. soln. with an onset potential of ca. 1.05 V (vs. the reversible hydrogen electrode) and a half-wave potential of 0.83 V, which is comparable to the com. Pt/C catalyst.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXps1ymur0%253D&md5=10187be0b83250e2bb4d4161b996deb3
297
Moussa, S. O.; Panchakarla, L. S.; Ho, M. Q.; El-Shall, M. S. Graphene-Supported, Iron-Based Nanoparticles for Catalytic Production of Liquid Hydrocarbons from Synthesis Gas: The Role of the Graphene Support in Comparison with Carbon Nanotubes ACS Catal. 2014, 4, 535– 545 DOI: 10.1021/cs4010198

Google Scholar

297
Graphene-Supported, Iron-Based Nanoparticles for Catalytic Production of Liquid Hydrocarbons from Synthesis Gas: The Role of the Graphene Support in Comparison with Carbon Nanotubes

Moussa, Sherif O.; Panchakarla, Leela S.; Ho, Minh Q.; El-Shall, M. Samy

ACS Catalysis (2014), 4 (2), 535-545CODEN: ACCACS; ISSN:2155-5435. (American Chemical Society)

Fischer-Tropsch synthesis (FTS) is a potentially attractive technol. for the prodn. of clean liq. fuels from synthesis gas. The efficiency and selectivity of FTS can be enhanced by the design of new active catalyst systems with improved selectivity for long-chain hydrocarbons and low methane prodn. In this paper, we introduce a new class of FT catalysts supported on the high surface area graphene nanosheets and report on their high activity and selectivity for the prodn. of long-chain hydrocarbons. The chem. redn. of graphene oxide in water in the presence of the metal salts under microwave irradn. allows the deposition of well-dispersed surface-oxidized metal nanoparticles on the defect sites of the graphene nanosheets. The Fe-K-nanoparticle catalyst supported on graphene exhibits high activity and selectivity toward C8 and higher hydrocarbons with excellent stability and recyclability. In comparison with other carbon supports, such as carbon nanotubes, the graphene support shows a unique tendency for minor formation of the low-value and undesirable products methane and carbon dioxide, resp. The water-gas shift activity is reduced on the graphene support as compared with CNTs, and as a result, the formation of CO2 is significantly reduced. Evidence is presented for the formation of the active Fe5C2 iron carbide phase during the FTS on the graphene-supported Fe catalysts. The high activity and selectivity of the catalysts supported on graphene are correlated with the presence of defects within the graphene lattice that act as favorable nucleation sites to anchor the metal nanoparticles, thus providing tunable metal-support interactions. Given the activity, selectivity, and stability of the new graphene-supported, Fe-based nanoparticle catalysts, their industrial application appears to be promising. Controlling the nature and d. of the defect sites in graphene could lead to improved understanding of the catalyst-graphene interactions and to further enhancement of the performance of these catalysts for the prodn. of liq. fuels.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvFymsLjP&md5=40c9922c18773e14ff917fa336f4b10f
298
Xu, X.; Li, H.; Zhang, Q.; Hu, H.; Zhao, Z.; Li, J.; Li, J.; Qiao, Y.; Gogotsi, Y. Self-Sensing, Ultra light, and Conductive 3D Graphene/Iron Oxide Aerogel Elastomer Deformable in a Magnetic Field ACS Nano 2015, 9, 3969– 3977 DOI: 10.1021/nn507426u

Google Scholar

There is no corresponding record for this reference.
299
Chen, Y.; Wang, Y. L.; Zhang, H. B.; Li, X. F.; Gui, C. X.; Yu, Z. Z. Enhanced Electromagnetic Interference Shielding Efficiency of Polystyrene/Graphene Composites with Magnetic Fe₃O₄ Nanoparticles Carbon 2015, 82, 67– 76 DOI: 10.1016/j.carbon.2014.10.031

Google Scholar

299
Enhanced electromagnetic interference shielding efficiency of polystyrene/graphene composites with magnetic Fe3O4 nanoparticles

Chen, Yu; Wang, Yongli; Zhang, Hao-Bin; Li, Xiaofeng; Gui, Chen-Xi; Yu, Zhong-Zhen

Carbon (2015), 82 (), 67-76CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

Polystyrene (PS) composites with satisfactory electromagnetic interference (EMI) shielding performance were prepd. by soln. blending of PS with thermally exfoliated and reduced graphene oxide (TGO) and modified Fe3O4 nanoparticles. For comparison, Fe3O4@reduced graphene oxide (RGO) hybrid and its PS composites were also prepd. The morphologies of Fe3O4@RGO hybrid and Fe3O4 nanoparticles were studied in terms of microstructure and magnetic properties. Surface modification of Fe3O4 nanoparticles enhances their compatibility with PS and thus their uniform dispersion in the PS matrix. Much higher elec. cond. and EMI shielding effectiveness are achieved for PS/TGO/Fe3O4 composites in comparison to those of PS/Fe3O4@RGO composites. Interestingly, PS/TGO/Fe3O4 composites exhibit obviously improved EMI shielding effectiveness in relative to that of PS/TGO composite although their elec. conductivities are similar. The EMI shielding effectiveness of PS/TGO/Fe3O4 composite is more than 30 dB in the frequency range of 9.8-12 GHz with only 2.24% of graphene. The effect of Fe3O4 size on the composite properties is investigated and the EMI shielding mechanism is discussed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsl2lt7nN&md5=c06486c88867f3c402ba781c664cf867
300
Yao, K.; Gong, J.; Tian, N. N.; Lin, Y. C.; Wen, X.; Jiang, Z. W.; Na, H.; Tang, T. Flammability Properties and Electromagnetic Interference Shielding of PVC/Graphene Composites Containing Fe₃O₄ nanoparticles RSC Adv. 2015, 5, 31910– 31919 DOI: 10.1039/C5RA01046B

Google Scholar

300
Flammability properties and electromagnetic interference shielding of PVC/graphene composites containing Fe3O4 nanoparticles

Yao, Kun; Gong, Jiang; Tian, Nana; Lin, Yichao; Wen, Xin; Jiang, Zhiwei; Na, Hui; Tang, Tao

RSC Advances (2015), 5 (40), 31910-31919CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

The effects of combined graphene/Fe3O4 nanoparticles on the flame retardancy and smoke suppression of PVC were studied. The dispersion state of graphene in the PVC matrix was improved with the help of Fe3O4 nanoparticles. As a result, the peak values of heat release rate and smoke prodn. rate measured by cone calorimetry were obviously decreased in the PVC/graphene/Fe3O4 composites. According to the results from TGA tests and structural characterization of residual char, the improved flame retardancy was partially attributed to the formation of a network-like structure due to the good dispersion state of graphene in the PVC matrix, and partially to the carbonization of degrdn. products of PVC catalyzed by Fe3O4 nanoparticles. In addn., ternary PVC composites showed higher mech. properties than pure PVC. More importantly, the resulting material possessed both elec. and magnetic properties. As a result, the ternary composites showed favorable electromagnetic shielding efficiency in the X-band frequency region (8-12 GHz), due to the formation of conducting interconnected graphene-based networks in the insulating PVC matrix and the magnetic properties.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsVOqtLo%253D&md5=bab4a4f7bcbcdbc4e01b8cb75090f6ad
301
Singh, A. P.; Mishra, M.; Hashim, D. P.; Narayanan, T. N.; Hahm, M. G.; Kumar, P.; Dwfuedi, J.; Kedawat, G.; Gupta, A.; Singh, B. P. Probing the Engineered Sandwich Network of Vertically Aligned Carbon Nanotube-Reduced Graphene Oxide Composites for High Performance Electromagnetic Interference Shielding Applications Carbon 2015, 85, 79– 88 DOI: 10.1016/j.carbon.2014.12.065

Google Scholar

301
Probing the engineered sandwich network of vertically aligned carbon nanotube-reduced graphene oxide composites for high performance electromagnetic interference shielding applications

Singh, Avanish Pratap; Mishra, Monika; Hashim, Daniel P.; Narayanan, T. N.; Hahm, Myung Gwan; Kumar, Pawan; Dwivedi, Jaya; Kedawat, Garima; Gupta, Ankit; Singh, Bhanu Pratap; Chandra, Amita; Vajtai, Robert; Dhawan, S. K.; Ajayan, Pulickel M.; Gupta, Bipin Kumar

Carbon (2015), 85 (), 79-88CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

Herein, the authors developed a strategy for fabrication of iron oxide infiltrated vertically aligned multiwalled carbon nanotubes (MWCNT forest) sandwiched with reduced graphene oxide (rGO) sheets network for high performance electromagnetic interference (EMI) shielding application which offers a new avenue in this area. Such engineered sandwiched network exhibits enhanced shielding effectiveness compared to conventional EMI shielding materials. This network of exotic carbons demonstrates the shielding effectiveness value >37 dB (>99.98% attenuation) in Ku-band (12.4-18 GHz), which is greater than the recommended limit (∼30 dB) for techno-com. applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitVagtw%253D%253D&md5=d60bf22e3c7e886c75a9de8258e21e64
302
Kumar, S.; Singh, A. K.; Dasmahapatra, A. K.; Mandal, T. K.; Bandyopadhyay, D. Graphene Based Multifunctional Superbots Carbon 2015, 89, 31– 40 DOI: 10.1016/j.carbon.2015.03.012

Google Scholar

302
Graphene based multifunctional superbots

Kumar, Sunny; Singh, Amit Kumar; Dasmahapatra, Ashok Kumar; Mandal, Tapas Kumar; Bandyopadhyay, Dipankar

Carbon (2015), 89 (), 31-40CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

A versatile graphene coated glass microswimmer displayed directed motions under the influence of applied elec. field, chem. potential gradient and external magnetic field. The directed chem. locomotion took place from the region of lower to higher pH with speed ∼13 body lengths per s due to asym. catalytic decompn. of dil. hydrogen peroxide across the motor surface. The neg. surface potential of graphene coated motor developed an elec. double layer in an alk. medium which in turn engendered electrophoretic mobility towards anode when the external electrostatic field was applied. Inclusion of sparsely populated ferromagnetic iron nanoparticles on the surface of the motor offered the magnetic remote control on the motion. The coupled in situ and external controls enabled the motor to develop complex motions in diverse open and confined environments. For example, the motor could approach, pick-up, tow, and release a heavy cargo inside microchannel. Remarkably, the motor (∼67 μg) could successfully drive out a ∼1000 times heavier payload (∼0.67 mg) displaying the ability to overcome the drag force of ∼2619 pN with the help of coupled in situ and remote guidance.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXktlOrurw%253D&md5=3f1c308257a43de382fb8ad544036906
303
Jiang, Z.; Li, J.; Aslan, H.; Li, Q.; Li, Y.; Chen, M.; Huang, Y.; Froning, J. P.; Otyepka, M.; Zboril, R. A High Efficiency H₂S Gas Sensor Material: Paper Like Fe₂O₃/graphene Nanosheets and Structural Alignment Dependency of Device Efficiency J. Mater. Chem. A 2014, 2, 6714– 6717 DOI: 10.1039/c3ta15180h

Google Scholar

303
A high efficiency H2S gas sensor material: paper like Fe2O3/graphene nanosheets and structural alignment dependency of device efficiency

Jiang, Zaixing; Li, Jun; Aslan, Huesnue; Li, Qiang; Li, Yue; Chen, Menglin; Huang, Yudong; Froning, Jens Peter; Otyepka, Michal; Zboril, Radek; Besenbacher, Flemming; Dong, Mingdong

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (19), 6714-6717CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Fe2O3/graphene was synthesized successfully by a super crit. CO2-assisted thermal method and further made into paper-like nanosheets by directed-flow, vertical assembly of individual Fe2O3/graphene nanosheets under a controlled magnetic field. Characterization of the samples was carried out by both electron microscopy and XPS. The sensor materials outperform many other paper-like materials for H2S gas detection. In addn., vertically and horizontally aligned nanosheets were used as sensing materials to detect H2S gas along with chemiluminescence measurements. Importantly, the nanoscale Fe2O3/graphene sheets with the vertical arrangement are more beneficial than the nanosheets with the horizontal arrangement in terms of sensitivity.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXmtlGgtbc%253D&md5=f87a6600d13e606dc5e1b77c9c2df303
304
Wang, K.; Wan, S.; Liu, Q.; Yang, N.; Zhai, J. CdS Quantum Dot-Decorated Titania/Graphene Nanosheets Stacking Structures for Enhanced Photoelectrochemical Solar Cells RSC Adv. 2013, 3, 23755– 23761 DOI: 10.1039/c3ra43770a

Google Scholar

304
CdS quantum dot-decorated titania/graphene nanosheets stacking structures for enhanced photoelectrochemical solar cells

Wang, Kefeng; Wan, Sijie; Liu, Qingqing; Yang, Nailiang; Zhai, Jin

RSC Advances (2013), 3 (45), 23755-23761CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

Quantum dot (QD)-decorated stacking structures of graphene (G) and titania nanosheets (TNS) have been fabricated through a layer-by-layer technique assocd. with a successive ionic layer adsorption and reaction method. The photoanodes with such stacking structures exhibit enhanced photocurrent responses under simulated solar light irradn. Compared with the photoanodes without graphene, the photoanodes integrated with graphene could greatly enhance the photocurrent generation. Though the thickness of the multilayer films in our expt. is on the nanometer scale, a considerable photoelec. conversion efficiency has been obtained by employing such a stacking structure for the photoelectrochem. solar cell. The stacking structure synchronously taking advantage of the conductive property of graphene and the visible light-harvesting ability of quantum dots will enlighten the fabrication of novel energy conversion devices.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs1yltrfE&md5=f6de3127f542bd2418509a7e6c8a382b
305
Bi, E.; Su, Y.; Chen, H.; Yang, X.; Yin, M.; Ye, F.; Li, Z.; Han, L. A Hybrid Catalyst Composed of Reduced Graphene Oxide/Cu₂S Quantum Dots as a Transparent Counter Electrode for Dye Sensitized Solar Cells RSC Adv. 2015, 5, 9075– 9078 DOI: 10.1039/C4RA14029J

Google Scholar

305
A hybrid catalyst composed of reduced graphene oxide/Cu2S quantum dots as a transparent counter electrode for dye sensitized solar cells

Bi, Enbing; Su, Yanjie; Chen, Han; Yang, Xudong; Yin, Maoshu; Ye, Fei; Li, Zhongli; Han, Liyuan

RSC Advances (2015), 5 (12), 9075-9078CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

We synthesized a hybrid catalyst of reduced graphene oxide/Cu2S quantum dots (RGO/Cu2S QDs) via a facile wet chem. approach. The synergistic effect between ultrathin-RGO and ultrasmall-QDs endowed the hybrid catalyst with a high transparent performance, excellent cond. and catalytic activity. A dye-sensitized solar cell fabricated with the hybrid catalyst showed the overall power conversion efficiency was 7.12%, which was comparable to that of a Pt-based device.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFOgtbzP&md5=47b02367136bfc4c382894b203aee0b8
306
Fu, M.; Jiao, Q.; Zhao, Y. One-Step Vapor Diffusion Synthesis of Uniform CdS Quantum Dots/Reduced Graphene Oxide Composites as Efficient Visible-Light Photocatalysts RSC Adv. 2014, 4, 23242– 23250 DOI: 10.1039/c4ra02000f

Google Scholar

306
One-step vapor diffusion synthesis of uniform CdS quantum dots/reduced graphene oxide composites as efficient visible-light photocatalysts

Fu, Min; Jiao, Qingze; Zhao, Yun

RSC Advances (2014), 4 (44), 23242-23250CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

CdS quantum dots (QDs)/reduced graphene oxide (RGO) composites were synthesized through a one-step vapor diffusion process in the presence of ethylene glycol. The in situ growth of CdS QDs and the redn. of graphene oxide (GO) were completed simultaneously. Fourier transform IR spectra, X-ray diffraction patterns, XPS and Raman spectroscopy confirmed the redn. of GO. Electron microscopy indicated uniform CdS QDs with size around 4-7 nm were well distributed on the RGO sheets. The transient photocurrent response, electrochem. impedance spectroscopy and diffuse reflectance UV-visible spectra of CdS QDs/RGO composites and CdS were tested to explain the role of RGO for the photocatalytic reaction. As-obtained composites exhibited better photocatalytic properties than pure CdS under visible light irradn. The influence of different contents of GO on photocatalytic performance was also investigated. A possible photocatalytic mechanism of CdS QDs/RGO composites was proposed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXpsVSisbo%253D&md5=94fc43061a648e2281dcf56b52dd8617
307
Mo, R.; Lei, Z.; Sun, K.; Rooney, D. Facile Synthesis of Anatase TiO₂ Quantum- Dot/Graphene Nanosheet Composites with Enhanced Electrochemical Performance for Lithium-Ion Batteries Adv. Mater. 2014, 26, 2084– 2088 DOI: 10.1002/adma.201304338

Google Scholar

There is no corresponding record for this reference.
308
Zeng, X.; Tu, W.; Li, J.; Bao, J.; Dai, Z. Photoelectrochemical Biosensor Using Enzyme-Catalyzed in Situ Propagation of CdS Quantum Dots on Graphene Oxide ACS Appl. Mater. Interfaces 2014, 6, 16197– 16203 DOI: 10.1021/am5043164

Google Scholar

308
Photoelectrochemical Biosensor Using Enzyme-Catalyzed in Situ Propagation of CdS Quantum Dots on Graphene Oxide

Zeng, Xianxiang; Tu, Wenwen; Li, Jing; Bao, Jianchun; Dai, Zhihui

ACS Applied Materials & Interfaces (2014), 6 (18), 16197-16203CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

An innovative photoelectrochem. (PEC) biosensor platform was designed based on the in situ generation of CdS quantum dots (QDs) on graphene oxide (GO) using an enzymic reaction. Horseradish peroxidase catalyzed the redn. of sodium thiosulfate with hydrogen peroxide to generate H2S, which reacted with Cd2+ to form CdS QDs. CdS QDs could be photoexcited to generate an elevated photocurrent as a readout signal. This strategy offered a "green" alternative to inconvenient presynthesis procedures for the fabrication of semiconducting nanoparticles. The nanomaterials and assembly procedures were characterized by microscopy and spectroscopy techniques. Combined with immune recognition and on the basis of the PEC activity of CdS QDs on GO, the strategy was successfully applied to a PEC assay to detect carcinoembryonic antigen and displayed a wide linear range from 2.5 ng mL-1 to 50 μg mL-1 and a detection limit of 0.72 ng mL-1 at a signal-to-noise ratio of 3. The PEC biosensor showed satisfactory performance for clin. sample detection and was convenient for detg. high concns. of solute without diln. This effort offers a new opportunity for the development of numerous rapid and convenient anal. techniques using the PEC method that may be applied in the design and prepn. of various solar-energy-driven applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVSrtb%252FE&md5=61df8a3c6fae059e342ce29b5b106dbd
309
Jiang, S.-D.; Tang, G.; Ma, Y.-F.; Hu, Y.; Song, L. Synthesis of Nitrogen-Doped Graphene-ZnS Quantum Dots Composites with Highly Efficient Visible Light Photodegradation Mater. Chem. Phys. 2015, 151, 34– 42 DOI: 10.1016/j.matchemphys.2014.11.019

Google Scholar

309
Synthesis of nitrogen-doped graphene-ZnS quantum dots composites with highly efficient visible light photodegradation

Jiang, Shu-Dong; Tang, Gang; Ma, Yi-Fei; Hu, Yuan; Song, Lei

Materials Chemistry and Physics (2015), 151 (), 34-42CODEN: MCHPDR; ISSN:0254-0584. (Elsevier B.V.)

Nitrogen-doped graphene-ZnS quantum dots (NG-ZnS QDs) were synthesized by a one-pot hydrothermal process using graphene oxide and [(Zn2S2) (pa)] nanosheets as precursors. The results demonstrated that ZnS QDs deposited on the surface of the nitrogen-doped graphene (NG). Combined with series of our anal. and characterization, we found that [(Zn2S2) (pa)] nanosheets were used not only as the sources of ZnS QDs but also as the sources of nitrogen. Moreover, photocatalytic expt. of NG-ZnS QDs for org. dyes was conducted under visible light irradn., and the results exhibited that the photocatalytic activities of resultant composites could be remarkably enhanced. This simple and catalyst-free approach for depositing ZnS QDs onto NG may provide an alternative way for prepn. of other composites based on NG under mild conditions, which showed their potential applications in wastewater treatment.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvV2nu77M&md5=a9483fae9131241f3eb8217c6f42223c
310
Xia, H.; Hong, C.; Li, B.; Zhao, B.; Lin, Z.; Zheng, M.; Savilov, S. V.; Aldoshin, S. M. Facile Synthesis of Hematite Quantum-Dot/Functionalized Graphene-Sheet Composites as Advanced Anode Materials for Asymmetric Supercapacitors Adv. Funct. Mater. 2015, 25, 627– 635 DOI: 10.1002/adfm.201403554

Google Scholar

310
Facile Synthesis of Hematite Quantum-Dot/Functionalized Graphene-Sheet Composites as Advanced Anode Materials for Asymmetric Supercapacitors

Xia, Hui; Hong, Caiyun; Li, Bo; Zhao, Bin; Lin, Zixia; Zheng, Mingbo; Savilov, Serguei V.; Aldoshin, Serguei M.

Advanced Functional Materials (2015), 25 (4), 627-635CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

For building high-energy d. asym. supercapacitors, developing anode materials with large specific capacitance remains a great challenge. Although Fe2O3 has been considered as a promising anode material for asym. supercapacitors, the specific capacitance of the Fe2O3-based anodes is still low and cannot match that of cathodes in the full cells. In this work, a composite material with well dispersed Fe2O3 quantum dots (QDs, ≈2 nm) decorated on functionalized graphene sheets (FGS) is prepd. by a facile and scalable method. The Fe2O3 QDs/FGS composites exhibit a large specific capacitance up to 347 F/g in 1M Na2SO4 between -1 and 0 V vs. Ag/AgCl. An asym. supercapacitor operating at 2 V is fabricated using Fe2O3/FGS as anode and MnO2/FGS as cathode in 1M Na2SO4 aq. electrolyte. The Fe2O3/FGS//MnO2/FGS asym. supercapacitor has a high energy d. of 50.7 W-h/kg at a power d. of 100 W/kg as well as excellent cycling stability and power capability. The facile synthesis method and superior supercapacitive performance of the Fe2O3 QDs/FGS composites make them promising as anode materials for high-performance asym. supercapacitors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVyhtbrL&md5=b144310053facad6d09a069a62846b31
311
Chao, D.; Zhu, C.; Xia, X.; Liu, J.; Zhang, X.; Wang, J.; Liang, P.; Lin, J.; Zhang, H.; Shen, Z. X. Graphene Quantum Dots Coated VO₂ Arrays for Highly Durable Electrodes for Li and Na Ion Batteries Nano Lett. 2015, 15, 565– 573 DOI: 10.1021/nl504038s

Google Scholar

311
Graphene Quantum Dots Coated VO2 Arrays for Highly Durable Electrodes for Li and Na Ion Batteries

Chao, Dongliang; Zhu, Changrong; Xia, Xinhui; Liu, Jilei; Zhang, Xiao; Wang, Jin; Liang, Pei; Lin, Jianyi; Zhang, Hua; Shen, Ze Xiang; Fan, Hong Jin

Nano Letters (2015), 15 (1), 565-573CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Nanoscale surface engineering is playing important role in enhancing the performance of battery electrode. VO2 is one of high-capacity but less-stable materials and has been used mostly in the form of powders for Li-ion battery cathode with mediocre performance. In this work, we design a new type of binder-free cathode by bottom-up growth of bifacial VO2 arrays directly on a graphene network for both high-performance Li-ion and Na-ion battery cathodes. More importantly, graphene quantum dots are coated onto the VO2 surfaces as a highly efficient surface sensitizer and protection to further boost the electrochem. properties. The integrated electrodes deliver a Na storage capacity of 306 mA-h/g at 100 mA/g, and a capacity of more than 110 mA-h/g after 1500 cycles at 18 A/g. Our result on Na-ion battery may pave the way to next generation post-lithium batteries.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFehsL7L&md5=64c5ad4c1680e984a714a38620297d09
312
Yeh, T. F.; Teng, C. Y.; Chen, S. J.; Teng, H. Nitrogen-Doped Graphene Oxide Quantum Dots as Photocatalysts for Overall Water-Splitting under Visible Light Illumination Adv. Mater. 2014, 26, 3297– 3303 DOI: 10.1002/adma.201305299

Google Scholar

312
Nitrogen-Doped Graphene Oxide Quantum Dots as Photocatalysts for Overall Water-Splitting under Visible Light Illumination

Yeh, Te-Fu; Teng, Chiao-Yi; Chen, Shean-Jen; Teng, Hsisheng

Advanced Materials (Weinheim, Germany) (2014), 26 (20), 3297-3303CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

Based on the structural characteristics required for photocatalytic water-splitting, we synthesized nitrogen-doped graphene oxide-quantum dots (NGO-QDs) as the catalyst. The NGO-QDs exhibited both p- and n-type conductivities, based on the results of the electrochem. Mott-Schottky anal. The prominent photo-luminescence emission indicated that photochem. p-n diodes constituted the NGO-QDs. The diode configuration resulted in an internal Z-scheme charge transfer for effective reaction at the QD interface. Visible light (>420 nm) irradn. on the NGO-QDs resulted in simultaneous H2 and O2 evolution from pure water at an H2:O2 molar ratio of 2:1. This paper demonstrated that graphene species are promising materials for synthesizing metal-free, cost-effective, and environmentally-friendly catalysts for overall water-splitting under solar illumination.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjtVKitLo%253D&md5=f4fd608871457493615d9bc17a724210
313
Chao, D.; Zhu, C.; Xia, X.; Liu, J.; Zhang, X.; Wang, J.; Liang, P.; Lin, J.; Zhang, H.; Shen, Z. X. Graphene Quantum Dots Coated VO₂ Arrays for Highly Durable Electrodes for Li and Na Ion Batteries Nano Lett. 2015, 15, 565– 573 DOI: 10.1021/nl504038s

Google Scholar

313
Graphene Quantum Dots Coated VO2 Arrays for Highly Durable Electrodes for Li and Na Ion Batteries

Chao, Dongliang; Zhu, Changrong; Xia, Xinhui; Liu, Jilei; Zhang, Xiao; Wang, Jin; Liang, Pei; Lin, Jianyi; Zhang, Hua; Shen, Ze Xiang; Fan, Hong Jin

Nano Letters (2015), 15 (1), 565-573CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Nanoscale surface engineering is playing important role in enhancing the performance of battery electrode. VO2 is one of high-capacity but less-stable materials and has been used mostly in the form of powders for Li-ion battery cathode with mediocre performance. In this work, we design a new type of binder-free cathode by bottom-up growth of bifacial VO2 arrays directly on a graphene network for both high-performance Li-ion and Na-ion battery cathodes. More importantly, graphene quantum dots are coated onto the VO2 surfaces as a highly efficient surface sensitizer and protection to further boost the electrochem. properties. The integrated electrodes deliver a Na storage capacity of 306 mA-h/g at 100 mA/g, and a capacity of more than 110 mA-h/g after 1500 cycles at 18 A/g. Our result on Na-ion battery may pave the way to next generation post-lithium batteries.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFehsL7L&md5=64c5ad4c1680e984a714a38620297d09
314
He, P.; Sun, J.; Tian, S.; Yang, S.; Ding, S.; Ding, G.; Xie, X.; Jiang, M. Processable Aqueous Dispersions of Graphene Stabilized by Graphene Quantum Dots Chem. Mater. 2015, 27, 218– 226 DOI: 10.1021/cm503782p

Google Scholar

314
Processable Aqueous Dispersions of Graphene Stabilized by Graphene Quantum Dots

He, Peng; Sun, Jing; Tian, Suyun; Yang, Siwei; Ding, Shengju; Ding, Guqiao; Xie, Xiaoming; Jiang, Mianheng

Chemistry of Materials (2015), 27 (1), 218-226CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)

Dispersing graphene in various solvents is one of the key technologies toward the practical applications of graphene. Herein, using graphene quantum dots (GQDs) as stabilizer, aq. dispersions of graphene with good stability were demonstrated by directly dispersing commercialized graphene powder into water. Amazingly, 100 mg of graphene powder could be stabilized by an av. of merely 7.8 mg GQDs to form aq. dispersions with a max. concn. of up to 0.4 mg/mL and stability at least 3 mo. The introduction of a small amt. of GQDs also allowed for the fabrication of water-redispersible graphene slurry and powder, which would largely facilitate the transportation and applications of graphene. The mechanism of the GQDs stabilized graphene in water was proposed and exptl. verified through UV-visible spectroscopy and zeta potential measurements. Moreover, flexible graphene papers directly assembled from the water-dispersible graphene exhibited controllable thickness, good cond., and acceptable strength. With properties not compromised by GQDs, water-dispersible graphene is expected to be widely applicable in elec. and electrochem. device fields.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVams7rF&md5=2551ba47c097dd467ef3202d5500dafe
315
Lin, Y.; Chapman, R.; Stevens, M. M. Integrative Self-Assembly of Graphene Quantum Dots and Biopolymers into a Versatile Biosensing Toolkit Adv. Funct. Mater. 2015, 25, 3183– 3192 DOI: 10.1002/adfm.201500624

Google Scholar

315
Integrative Self-Assembly of Graphene Quantum Dots and Biopolymers into a Versatile Biosensing Toolkit

Lin, Yiyang; Chapman, Robert; Stevens, Molly M.

Advanced Functional Materials (2015), 25 (21), 3183-3192CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

Hybrid self-assembly has become a reliable approach to synthesize soft materials with multiple levels of structural complexity and synergistic functionality. Photoluminescent graphene quantum dots (GQDs, 2-5 nm) were used for the first time as mol.-like building blocks to construct self-assembled hybrid materials for label-free biosensors. Ionic self-assembly of disk-shaped GQDs and charged biopolymers generates a series of hierarchical structures that exhibit aggregation-induced fluorescence quenching of the GQDs and change the protein/polypeptide secondary structure. The integration of GQDs and biopolymers via self-assembly offers a flexible toolkit for the design of label-free biosensors in which the GQDs serve as a fluorescent probe and the biopolymers provide biol. function. The versatility of this approach is demonstrated in the detection of glycosaminoglycans (GAGs), pH, and proteases using three strategies: (1) competitive binding of GAGs to biopolymers, (2) pH-responsive structural changes of polypeptides, and (3) enzymic hydrolysis of the protein backbone, resp. It is anticipated that the integrative self-assembly of biomols. and GQDs will open up new avenues for the design of multifunctional biomaterials with combined optoelectronic properties and biol. applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmsFyqs78%253D&md5=2bc64240a580ba1d416fe26e1a845811
316
Zhang, Q.; Jie, J.; Diao, S.; Shao, Z.; Zhang, Q.; Wang, L.; Deng, W.; Hu, W.; Xia, H.; Yuan, X. Solution-Processed Graphene Quantum Dot Deep-UV Photodetectors ACS Nano 2015, 9, 1561– 1570 DOI: 10.1021/acsnano.5b00437

Google Scholar

316
Solution-Processed Graphene Quantum Dot Deep-UV Photodetectors

Zhang, Qing; Jie, Jiansheng; Diao, Senlin; Shao, Zhibin; Zhang, Qiao; Wang, Liu; Deng, Wei; Hu, Weida; Xia, Hui; Yuan, Xiaodong; Lee, Shuit-Tong

ACS Nano (2015), 9 (2), 1561-1570CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Fast-response and high-sensitivity deep-UV (DUV) photodetectors with detection wavelength shorter than 320 nm are in high demand due to their potential applications in diverse fields. However, the fabrication processes of DUV detectors based on traditional semiconductor thin films are complicated and costly. Here we report a high-performance DUV photodetector based on graphene quantum dots (GQDs) fabricated via a facile soln. process. The devices are capable of detecting DUV light with wavelength as short as 254 nm. With the aid of an asym. electrode structure, the device performance could be significantly improved. An on/off ratio of ∼6000 under 254 nm illumination at a relatively weak light intensity of 42 μW cm-2 is achieved. The devices also exhibit excellent stability and reproducibility with a fast response speed. Given the soln.-processing capability of the devices and extraordinary properties of GQDs, the use of GQDs will open up unique opportunities for future high-performance, low-cost DUV photodetectors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhsF2itbo%253D&md5=71979acc7c275e07a0f809a8560ec60e
317
Song, S. H.; Jang, M. H.; Chung, J.; Jin, S. H.; Kim, B. H.; Hur, S. H.; Yoo, S. H.; Cho, Y. H.; Jeon, S. W. Highly Efficient Light-Emitting Diode of Graphene Quantum Dots Fabricated from Graphite Intercalation Compounds Adv. Opt. Mater. 2014, 2, 1016– 1023 DOI: 10.1002/adom.201400184

Google Scholar

317
Highly Efficient Light-Emitting Diode of Graphene Quantum Dots Fabricated from Graphite Intercalation Compounds

Song, Sung Ho; Jang, Min-Ho; Chung, Jin; Jin, Sung Hawn; Kim, Bo Hyun; Hur, Seung-Hyun; Yoo, Seunghyup; Cho, Yong-Hoon; Jeon, Seokwoo

Advanced Optical Materials (2014), 2 (11), 1016-1023CODEN: AOMDAX; ISSN:2195-1071. (Wiley-VCH Verlag GmbH & Co. KGaA)

This article describes highly efficient light-emitting diode of graphene quantum dots fabricated from graphite intercalation compds.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFagt7jO&md5=fcb4ae3463eafdbdea180d011f0d5e44
318
Kumar, P. N.; Mandal, S.; Deepa, M.; Srivastava, A. K.; Joshi, A. G. Functionalized Graphite Platelets and Lead Sulfide Quantum Dots Enhance Solar Conversion Capability of a Titanium Dioxide/Cadmium Sulfide Assembly J. Phys. Chem. C 2014, 118, 18924– 18937 DOI: 10.1021/jp5052408

Google Scholar

There is no corresponding record for this reference.
319
Jung, M. H.; Chu, M. J. Comparative Experiments of Graphene Covalently and Physically Binding CdSe Quantum Dots to Enhance the Electron Transport in Flexible Photovoltaic Devices Nanoscale 2014, 6, 9241– 9249 DOI: 10.1039/C4NR02254H

Google Scholar

319
Comparative experiments of graphene covalently and physically binding CdSe quantum dots to enhance the electron transport in flexible photovoltaic devices

Jung, Mi-Hee; Chu, Moo-Jung

Nanoscale (2014), 6 (15), 9241-9249CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

In this research, we prepd. composite films via covalent coupling of CdSe quantum dots (QDs) to graphene through the direct binding of aryl radicals to the graphene surface. To compare the carrier transport with the CdSe aryl binding graphene film, we prepd. CdSe pyridine capping graphene films through the pi-pi interactions of noncovalent bonds between the graphene and pyridine mols. The photovoltaic devices were fabricated from the two hybrid films using the electrophoretic deposition method on flexible substrates. Even though the two hybrid films have the same amt. of QDs and graphene, time-resolved fluorescence emission decay results show that the emission lifetime of the CdSe aryl group binding graphene film is significantly shorter than that of the pyridine capping CdSe-graphene. The quantum efficiency and photocurrent d. of the device fabricated from CdSe aryl binding graphene were also higher than those of the device fabricated from pyridine capping CdSe-graphene. These results indicated that the carrier transport of the QD-graphene system is not related to the additive effect from the CdSe and graphene components but rather is a result of the unique interactions between the graphene and QDs. We could expect that these results can be useful in designing QD-graphene composite materials, which are applied in photovoltaic devices.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVOitbvP&md5=3fe052de871b00626fee1afb0dc8107c
320
Guo, S.; Bao, D.; Upadhyayula, S.; Wang, W.; Guvenc, A. B.; Kyle, J. R.; Hosseinibay, H.; Bozhilov, K. N.; Vullev, V. I.; Ozkan, C. S. Photoinduced Electron Transfer Between Pyridine Coated Cadmium Selenide Quantum Dots and Single Sheet Graphene Adv. Funct. Mater. 2013, 23, 5199– 5211 DOI: 10.1002/adfm.201203652

Google Scholar

320
Photoinduced electron transfer between pyridine coated cadmium selenide quantum dots and single sheet graphene

Guo, Shirui; Bao, Duoduo; Upadhyayula, Srigokul; Wang, Wei; Guvenc, Ali B.; Kyle, Jennifer R.; Hosseinibay, Hamed; Bozhilov, Krassimir N.; Vullev, Valentine I.; Ozkan, Cengiz S.; Ozkan, Mihrimah

Advanced Functional Materials (2013), 23 (41), 5199-5211CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

Interest in graphene as a two-dimensional quantum-well material for energy applications and nanoelectronics has increased exponentially in the last few years. The recent advances in large-area single-sheet fabrication of pristine graphene have opened unexplored avenues for expanding from nano- to meso-scale applications. The relatively low level of absorptivity and the short lifetimes of excitons of single-sheet graphene suggest that it needs to be coupled with light sensitizers in order to explore its feasibility for photonic applications, such as solar-energy conversion. Red-emitting CdSe quantum dots are employed for photosensitizing single-sheet graphene with areas of several square centimeters. Pyridine coating of the quantum dots not only enhances their adhesion to the graphene surface, but also provides good electronic coupling between the CdSe and the two-dimensional carbon allotrope. Illumination of the quantum dots led to injection of n-carrier in the graphene phase. Time-resolved spectroscopy reveals three modes of photoinduced electron transfer between the quantum dots and the graphene occurring in the femtosecond and picosecond time-domains. Transient absorption spectra provide evidence for photoinduced hole-shift from the CdSe to the pyridine ligands, thereby polarizing the surface of the quantum dots. That is, photoinduced elec. polarization, which favors the simultaneous electron transfer from the CdSe to the graphene phase. These mechanistic insights into the photoinduced interfacial charge transfer have a promising potential to serve as guidelines for the design and development of composites of graphene and inorg. nanomaterials for solar-energy conversion applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXnt1SjsL0%253D&md5=fc0da7cbaaeb65e2809fa6c5edb592d0
321
Hirose, T.; Kutsuma, Y.; Kurita, A.; Kaneko, T.; Tamai, N. Blinking Suppression of CdTe Quantum Dots on Epitaxial Graphene and the Analysis with Marcus Electron Transfer Appl. Phys. Lett. 2014, 105, 083102 DOI: 10.1063/1.4893667

Google Scholar

There is no corresponding record for this reference.
322
Liu, J.; Kumar, P.; Hu, Y.; Cheng, G. J.; Irudayaraj, J. Enhanced Multiphoton Emission from CdTe/ZnS Quantum Dots Decorated on Single-Layer Graphene J. Phys. Chem. C 2015, 119, 6331– 6336 DOI: 10.1021/jp5123147

Google Scholar

There is no corresponding record for this reference.
323
Qin, J.; Wang, X.; Cao, M.; Hu, C. Germanium Quantum Dots Embedded in N-Doping Graphene Matrix with Sponge-Like Architecture for Enhanced Performance in Lithium-Ion Batteries Chem. - Eur. J. 2014, 20, 9675– 9682 DOI: 10.1002/chem.201402151

Google Scholar

323
Germanium Quantum Dots Embedded in N-Doping Graphene Matrix with Sponge-Like Architecture for Enhanced Performance in Lithium Ion Batteries

Qin, Jinwen; Wang, Xia; Cao, Minhua; Hu, Changwen

Chemistry - A European Journal (2014), 20 (31), 9675-9682CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)

Germanium quantum dots embedded in a nitrogen-doped graphene matrix with a sponge-like architecture (Ge/GN sponge) are prepd. through a simple and scalable synthetic method, involving freeze drying to obtain the Ge(OH)4/graphene oxide (GO) precursor and subsequent heat redn. treatment. Upon application as an anode for the lithium-ion battery (LIB), the Ge/GN sponge exhibits a high discharge capacity compared with previously reported N-doped graphene. The electrode with the as-synthesized Ge/GN sponge can deliver a capacity of 1258 mAh g-1 even after 50 charge/discharge cycles. This improved electrochem. performance can be attributed to the pore memory effect and highly conductive N-doping GN matrix from the unique sponge-like structure.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFWns77L&md5=490e504f4cf85d6c062e11bbd25fd6d7
324
Sun, X.; Zhou, C.; Xie, M.; Sun, H.; Hu, T.; Lu, F.; Scott, S. M.; George, S. M.; Lian, J. Synthesis of ZnO Quantum Dot/Graphene Nanocomposites by Atomic Layer Deposition with High Lithium Storage Capacity J. Mater. Chem. A 2014, 2, 7319– 7326 DOI: 10.1039/C4TA00589A

Google Scholar

324
Synthesis of ZnO quantum dot/graphene nanocomposites by atomic layer deposition with high lithium storage capacity

Sun, Xiang; Zhou, Changgong; Xie, Ming; Sun, Hongtao; Hu, Tao; Lu, Fengyuan; Scott, Spencer M.; George, Steven M.; Lian, Jie

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (20), 7319-7326CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Zinc oxide, as an inexpensive anode material, has attracted less attention than other metal oxides due to its poor cycling stability. A rational design of ZnO nanostructures with well-controlled particle sizes and microstructures is essential to improve their stability and performance as electrodes for lithium ion batteries (LIBs). Here, we demonstrate a simple approach via at. layer deposition (ALD) to synthesize ZnO quantum dots (QDs) on graphene layers, in which the size of the ZnO QDs can be controlled from 2 to 7 nm by ALD cycles. A strong relationship between size and electrochem. performance is obsd., in which smaller sized QDs on graphene display enhanced electrochem. performance. A high reversible specific capacity of 960 mA.h.g-1 is achieved at a c.d. of 100 mA.g-1 for 2 nm ZnO QDs, approaching to the theor. value of ZnO as the LIB anode. The greatly enhanced cycling stability and rate performance of the ALD ZnO QD/graphene composite electrode can be attributed to the well-maintained structural integrity without pulverization upon electrochem. charge/discharge for ZnO QDs with the grain size below a crit. value.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXmslGrt78%253D&md5=03d17e20e7f98cee0ab380876013ebae
325
Zhou, X.; Shi, J.; Liu, Y.; Su, Q.; Zhang, J.; Du, G. Microwave Irradiation Synthesis of Co₃O₄ Quantum Dots/Graphene Composite as Anode Materials for Li-Ion Battery Electrochim. Acta 2014, 143, 175– 179 DOI: 10.1016/j.electacta.2014.08.023

Google Scholar

325
Microwave irradiation synthesis of Co3O4 quantum dots/graphene composite as anode materials for Li-ion battery

Zhou, Xiaoyan; Shi, Jingjing; Liu, Ya; Su, Qingmei; Zhang, Jun; Du, Gaohui

Electrochimica Acta (2014), 143 (), 175-179CODEN: ELCAAV; ISSN:0013-4686. (Elsevier Ltd.)

Co3O4 quantum dots/graphene composites were synthesized by a facile and efficient microwave irradn. method, and they were analyzed using XRD, TEM, HRTEM, and TG. Uniform Co3O4 nanocrystals of ∼3-8 nm with a high d. are homogeneously dispersed on graphene nanosheets. When used as anode materials for Li-ion batteries, the Co3O4 quantum dots/graphene composites show a significantly enhanced cycling performance (1785 mAh g-1 at 0.1 C after 90 cycles) as well as high rate capability (485 mAh g-1 at 5 C). The reversible capacity is much higher than the theor. value. The superior performance could be attributed to the interfacial Li-storage and the quantum and size effects of quantum dots that lead to high activity during the lithiation/delithiation process. The flexible and conductive graphene nanosheets and well dispersed Co3O4 nanodots as well as the synergetic effect between them also benefit the electrochem. performance by endowing a superior high surface area and shortening the diffusion pathway of Li ions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVakur7I&md5=27278aea1b6efbc2f50916ee72a460a2
326
Zhao, S.; Xie, D.; Yu, X.; Su, Q.; Zhang, J.; Du, G. Facile Synthesis of Fe₃O₄@C Quantum Dots/Graphene Nanocomposite with Enhanced Lithium-Storage Performance Mater. Lett. 2015, 142, 287– 290 DOI: 10.1016/j.matlet.2014.12.051

Google Scholar

326
Facile synthesis of Fe3O4@C quantum dots/graphene nanocomposite with enhanced lithium-storage performance

Zhao, Saihua; Xie, Dong; Yu, Xudong; Su, Qingmei; Zhang, Jun; Du, Gaohui

Materials Letters (2015), 142 (), 287-290CODEN: MLETDJ; ISSN:0167-577X. (Elsevier B.V.)

Carbon-coated Fe3O4 quantum dots/graphene composite was prepd. by a hydrothermal and calcining process. X-ray diffraction and TEM anal. revealed that carbon-coated Fe3O4 quantum dots with a size around 7-10 nm were distributed uniformly on graphene nanosheets. The carbon shell can preserve structural stabilization of Fe3O4 nanoparticles by preventing the aggregation and buffering the vol. expansion during charge/discharge processes. In addn., the graphene nanosheets formed a three-dimensional network for the transportation of Li+ ions and electrons. When evaluated as anode material for lithium-ion batteries, the nanocomposite showed an improved lithium-storage performance with high cycling stability and good rate capacity. Furthermore, it exhibited an initial discharge capacity of 1300 mA-h/g and retained a reversible capacity of about 940 mA-h/g after 100 cycles at a c.d. of 150 mA/g.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFygt7%252FP&md5=6341530236522502ac2c442c0b9c7c90
327
Wei, W.; Yang, S.; Zhou, H.; Lieberwirth, I.; Feng, X.; Müllen, K. 3D Graphene Foams Cross-linked with Pre-encapsulated Fe₃O₄ Nanospheres for Enhanced Lithium Storage Adv. Mater. 2013, 25, 2909– 2914 DOI: 10.1002/adma.201300445

Google Scholar

327
3D Graphene Foams Cross-linked with Pre-encapsulated Fe3O4 Nanospheres for Enhanced Lithium Storage

Wei, Wei; Yang, Shubin; Zhou, Haixin; Lieberwirth, Ingo; Feng, Xinliang; Muellen, Klaus

Advanced Materials (Weinheim, Germany) (2013), 25 (21), 2909-2914CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

The three-dimensional graphene/Fe3O4 foams consisting of interior graphene-encapsulated Fe3O4 NSs and exterior porous graphene networks were fabricated. Such a unique architecture established by graphene sheets provides double protection against the aggregation and vol. changes of Fe3O4 active materials, and ensures favorable transport kinetics for both electrons and lithium ions. As a consequence, superior cycling performance (1059 mAh g-1 over 150 cycles) and excellent rate capability (363 mAhg-1 at 4800 mA g-1) were achieved when Fe3O4@GS/GF was used as anode material for lithium storage. Such a protocol to construct 3D hierarchical graphene frameworks can be further extended to other metals or metal oxides for electrochem. energy storage and conversion applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXmtleisrc%253D&md5=931270e7e70a42c0ee14a39cfe9e7af9
328
Tayyebi, A.; Tavakoli, M. M.; Outokesh, M.; Shafiekhani, A.; Simchi, A. Supercritical Synthesis and Characterization of Graphene-PbS Quantum Dots Composite with Enhanced Photovoltaic Properties Ind. Eng. Chem. Res. 2015, 54, 7382– 7392 DOI: 10.1021/acs.iecr.5b00008

Google Scholar

328
Supercritical Synthesis and Characterization of Graphene-PbS Quantum Dots Composite with Enhanced Photovoltaic Properties

Tayyebi, Ahmad; Tavakoli, Mohammad Mahdi; Outokesh, Mohammad; Shafiekhani, Azizollah; Simchi, Abdolreza

Industrial & Engineering Chemistry Research (2015), 54 (30), 7382-7392CODEN: IECRED; ISSN:0888-5885. (American Chemical Society)

Lead sulfide quantum dots (PbS QDs) were decorated onto a graphene surface in a semi-core-shell structure using supercrit. EtOH. The temp. of EtOH played significant role in controlling size and agglomeration of QDs as well as the extent of redn. of graphene. Av. size of the QDs was estd. by TEM to be around 3.96 nm and by quantum models to be ∼4.34 nm. PbS QDs prepd. at 330° were of high purity, and the yield was 99%. Instrumental and chem. analyses demonstrated formation of a strong bond between PbS QDs and graphene, through a Pb-O-C bridge. UV and photoluminescence measurements along with theor. considerations revealed that integration of PbS QDs with graphene results in efficient sepn. of the electron-hole, thus enhancing photo → elec. energy conversion. This outcome was further evidenced by comparison of performance of PbS/G in a solar cell, with the performance of pristine PbS QDs.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtFSrtLbF&md5=e3ea4ee05700a1dd3f008d13cbbc2bcd
329
Gao, H.; Shangguan, W.; Hu, G.; Zhu, K. Preparation and Photocatalytic Performance of Transparent Titania Film from Monolayer Titania Quantum Dots Appl. Catal., B 2016, 180, 416– 423 DOI: 10.1016/j.apcatb.2015.06.049

Google Scholar

329
Preparation and photocatalytic performance of transparent titania film from monolayer titania quantum dots

Gao, Hanyang; Shangguan, Wenfeng; Hu, Guoxin; Zhu, Kunxu

Applied Catalysis, B: Environmental (2016), 180 (), 416-423CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)

By using monolayer titania quantum dots (MTQDs) colloid, a continuous and transparent ultrathin titania film was prepd. simply by drop-cast metals or spray coating process method at room temp. The formation of this even and ultrathin film was not only because of the very thin thickness of two-dimensional MTQDs, but also because of the suppression of coffee-ring effect. The self-assembly behaviors of MTQDs were examd. by AFM and the reason for the suppression of coffee-ring effect was discussed in detail. Furthermore, the photocatalytic performance of this MTQDs film was evaluated and an improvement was achieved by loading graphene. Comparison between MTQDs/graphene composite and sphere-shaped nanoTiO2/graphene composite indicated that, the face-to-face contact mode between MTQDs and graphene may contribute to the high activity of MTQDs/graphene composite.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtFGksLrP&md5=c946cb15c0d94a99490860cacd137c8d
330
Cao, S.; Chen, C.; Zhang, J.; Zhang, C.; Yu, W.; Liang, B.; Tsang, Y. MnO_x Quantum Dots Decorated Reduced Graphene Oxide/TiO₂ Nanohybrids for Enhanced Activity by a UV Pre-Catalytic Microwave Method Appl. Catal., B 2015, 176–177, 500– 512 DOI: 10.1016/j.apcatb.2015.04.041

Google Scholar

330
MnOx quantum dots decorated reduced graphene oxide/TiO2 nanohybrids for enhanced activity by a UV pre-catalytic microwave method

Cao, Shiyi; Chen, Chuansheng; Zhang, Juyan; Zhang, Cui; Yu, Weiwei; Liang, Bo; Tsang, Yuenhong

Applied Catalysis, B: Environmental (2015), 176-177 (), 500-512CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)

Graphene/TiO2-based catalysts have attracted much attention as promising photocatalysts because of their low cost and excellent performance. In this report, we integrated the energy storage with high photocatalytic activity into a new simulation, physicochem. for wider applications in the field of energy utilization and environmental treatment. The MnOx quantum dots were decorated on reduced graphene oxide/TiO2 hybrids (GTM) by combining UV excitation with microwave method for the first time. Exptl. results show that GTM nanohybrids have excellent photocatalytic activity for org. dyes under UV-vis light and good antibacterial activity. Besides, UV preexcitation can improve the adsorbability and photocatalytic durability of GTM nanohybrids for high-concn. dyes. These enhancements are attributed to the rapid sepn. of photogenerated carriers from reduced graphene oxide and surface defects induced by UV excitation, and the broad light absorption aroused by the narrow band gap and MnOx quantum dots simultaneously.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmvFamu7g%253D&md5=9f32f3a2d078fb9503f8ea5fc46cbab2
331
Kaur, P.; Shin, M. S.; Sharma, N.; Kaur, N.; Joshi, A.; Chae, S. R.; Park, J. S.; Kang, M. S.; Sekhon, S. S. Non-Covalent Functionalization of Graphene with Poly(diallyl dimethylammonium) Chloride: Effect of a Non-Ionic Surfactant Int. J. Hydrogen Energy 2015, 40, 1541– 1547 DOI: 10.1016/j.ijhydene.2014.11.068

Google Scholar

331
Non-covalent functionalization of graphene with poly(diallyl dimethylammonium) chloride: Effect of a non-ionic surfactant

Kaur, Prabhsharan; Shin, Mun-Sik; Sharma, Neha; Kaur, Namarta; Joshi, Anjali; Chae, So-Ryong; Park, Jin-Soo; Kang, Moon-Sung; Sekhon, Satpal Singh

International Journal of Hydrogen Energy (2015), 40 (3), 1541-1547CODEN: IJHEDX; ISSN:0360-3199. (Elsevier Ltd.)

Carbon based nanomaterials (carbon nanotubes, graphene etc) contg. various hetero atoms are promising metal free catalysts for oxygen redn. reaction in fuel cells. We report the non-covalent functionalization of graphene with poly(diallyl dimethylammonium) chloride (PDDA), a polyelectrolyte contg. nitrogen, using a very simple method. The addn. of a non-ionic surfactant (Triton X-100) during functionalization has been obsd. to improve the interactions between graphene and PDDA. An up-shift in the position of G-peak in the Raman spectra, down-shift in the binding energy (B.E.) of N1s peak and an up-shift in the B.E. of C1s peak in XPS spectra have been obsd. due to an inter-mol. charge-transfer from carbon in graphene to nitrogen in PDDA, which get enhanced in the presence of Triton X-100. Graphene functionalized with PDDA also show good thermal stability. The addn. of a non-ionic surfactant enhances the non-covalent functionalization of graphene with PDDA, which is desirable from applications point of view.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVWrs7vN&md5=bec41842f02b35476f517bee331304f0
332
Tiwari, J. N.; Tiwari, R. N.; Kim, K. S. Zero-Dimensional, One-Dimensional, Two-Dimensional and Three-Dimensional Nanostructured Materials for Advanced Electrochemical Energy Devices Prog. Mater. Sci. 2012, 57, 724– 803 DOI: 10.1016/j.pmatsci.2011.08.003

Google Scholar

332
Zero-dimensional, one-dimensional, two-dimensional and three-dimensional nanostructured materials for advanced electrochemical energy devices

Tiwari, Jitendra N.; Tiwari, Rajanish N.; Kim, Kwang S.

Progress in Materials Science (2012), 57 (4), 724-803CODEN: PRMSAQ; ISSN:0079-6425. (Elsevier Ltd.)

A review. One of the biggest challenges of 21st century is to develop powerful electrochem. energy devices (EEDs). The EEDs such as fuel cells, supercapacitors, and Li-ion batteries are among the most promising candidates in terms of power-densities and energy-densities. The nanostructured materials (NSMs) have drawn intense attention to develop highly efficient EEDs because of their high surface area, novel size effects, significantly enhanced kinetics, and so on. In this review article, we briefly introduce general synthesis, fabrication and their classification as zero-dimensional (0D), one dimensional (1D), two-dimensional (2D) and three-dimensional (3D) NSMs. Subsequently, we focus an attention on recent progress in advanced NSMs as building blocks for EEDs (such as fuel cells, supercapacitors, and Li-ion batteries) based on investigations at the 0D, 1D, 2D and 3D NSMs.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XitFCrsr4%253D&md5=8c3a4c5282cef7f9b87005af5769bba5
333
Tiwari, J. N.; Tiwari, R. N.; Singh, G.; Kim, K. S. Recent Progress in the Development of Anode and Cathode Catalysts for Direct Methanol Fuel Cells Nano Energy 2013, 2, 553– 578 DOI: 10.1016/j.nanoen.2013.06.009

Google Scholar

333
Recent progress in the development of anode and cathode catalysts for direct methanol fuel cells

Tiwari, Jitendra N.; Tiwari, Rajanish N.; Singh, Gyan; Kim, Kwang S.

Nano Energy (2013), 2 (5), 553-578CODEN: NEANCA; ISSN:2211-2855. (Elsevier Ltd.)

A review. Continuous growth in global energy demand has sparked concerns about energy security and environmental sustainability. In the past two decades, attempts have been made in the development of innovative energy technologies. The direct methanol fuel cell (DMFC) is among the most promising alternative energy sources for the near future. Simple construction, compact design, high energy d. and relatively high energy-conversion efficiency give the DMFC an advantage over other promising power sources in terms of portability. However, the translation of DMFCs into com. successful products is precluded due to poor performance. In addn., low activity, poor durability and reliability and an expensive anode and cathode further discourage the application of DMFCs. In this regard, the present review article focuses on recent progress in the development of anode and cathode catalysts for DMFCs. The first part of the review discusses the recent developments in the synthesis of single-, double-, and multiple-component catalysts and new catalyst supports for anode electrodes. The section is followed by the chem. approaches employed to make alloys and composite catalysts, aiming to enhance their activity, reliability and durability for the methanol oxidn. reaction. Finally, exciting new research that pushes the development of single-, double-, and multiple-component catalysts and new catalyst supports for cathode electrodes is introduced. In addn., size-, shape- and compn.-dependent electrocatalysts that are advocated for methanol oxidn. at the anode and oxygen redn. at the cathode are highlighted to illustrate the potential of the newly developed electrocatalysts for DMFC applications. Moreover, this article provides a comprehensive review of the exptl. work that is devoted to understanding the fundamental problems and recent progress in the development of anode and cathode catalysts for DMFCs.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs1WhsbvJ&md5=af8df026389549837b50e7fb4e296806
334
Tiwari, J. N.; Tiwari, R. N.; Chang, Y.-M.; Lin, K.-L. A Promising Approach to the Synthesis of 3D Nanoporous Graphitic Carbon as a Unique Electrocatalyst Support for Methanol Oxidation ChemSusChem 2010, 3, 460– 466 DOI: 10.1002/cssc.200900223

Google Scholar

There is no corresponding record for this reference.
335
Tiwari, J. N.; Tiwari, R. N.; Singh, G.; Lin, K.-L. Direct Synthesis of Vertically Interconnected 3-D Graphitic Nanosheets on Hemispherical Carbon Particles by Microwave Plasma CVD Plasmonics 2011, 6, 67– 73 DOI: 10.1007/s11468-010-9170-7

Google Scholar

335
Direct synthesis of vertically interconnected 3-D graphitic nanosheets on hemispherical carbon particles by microwave plasma CVD

Tiwari, Jitendra N.; Tiwari, Rajanish N.; Singh, Gyan; Lin, Kun-Lin

Plasmonics (2011), 6 (1), 67-73CODEN: PLASCS; ISSN:1557-1955. (Springer)

High-quality, free-standing, and vertically interconnected three-dimensional (3-D) graphitic nanosheets (GNSs) were synthesized over the surface of hemispherical carbon particles/GaN at 700 °C by microwave plasma chem. vapor deposition (CVD) in presence of methane gas, whereas the hemispherical carbon particles have been directly deposited on GaN/sapphire template. The GNSs are ∼1-5 nm in thickness and have a graphitic flake structure on hemispherical carbon particles. The vertically interconnected 3-D GNSs on hemispherical carbon particles have been characterized by SEM, transmission electron microscopy, selective area electron diffraction pattern, X-ray diffraction, at. force microscopy, Raman spectroscopy, XPS, and nitrogen gas adsorption-Brunauer-Emmet-Teller. The present CVD approach is capable of producing large quantities of GNSs with high purity. Moreover, a high-purity free-standing and vertically interconnected 3-D GNSs on hemispherical carbon particles have an enormous potential for applications in electronic devices, biol. sensors, gas uptake and storage, fuel cells, lithium ion batteries, and more.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXjs1Ckur0%253D&md5=dcb05e4c7667069f9b259383a1b59b3b
336
Dubey, P.; Kumar, A.; Prakash, R. Non-Covalent Functionalization of Graphene Oxide by Polyindole and Subsequent Incorporation of Ag Nanoparticles for Electrochemical Applications Appl. Surf. Sci. 2015, 355, 262– 267 DOI: 10.1016/j.apsusc.2015.07.079

Google Scholar

There is no corresponding record for this reference.
337
Campbell, P. G.; Merrill, M. D.; Wood, B. C.; Montalvo, E.; Worsley, M. A.; Baumann, T. F.; Biener, J. Battery/Supercapacitor Hybrid via Non-Covalent Functionalization of Graphene Macro-Assemblies J. Mater. Chem. A 2014, 2, 17764– 17770 DOI: 10.1039/C4TA03605K

Google Scholar

337
Battery/supercapacitor hybrid via non-covalent functionalization of graphene macro-assemblies

Campbell, P. G.; Merrill, M. D.; Wood, B. C.; Montalvo, E.; Worsley, M. A.; Baumann, T. F.; Biener, J.

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (42), 17764-17770CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Binder-free, monolithic, high surface area graphene macro-assemblies (GMAs) are promising materials for supercapacitor electrodes, but, like all graphitic carbon based supercapacitor electrodes, still lack sufficient energy d. for demanding practical applications. Here, we demonstrate that the energy storage capacity of GMAs can be increased nearly 3-fold (up to 23 W h kg-1) by facile, non-covalent surface modification with anthraquinone (AQ). AQ provides battery-like redox charge storage (927 C g-1) without affecting the cond. and capacitance of the GMA support. The resulting AQ-GMA battery/supercapacitor hybrid electrodes demonstrate excellent power performance, show remarkable long-term cycling stability and, by virtue of their excellent mech. properties, allow for further increases in volumetric energy d. by mech. compression of the treated electrode. Our measured capacity is very close to the theor. max. obtained using detailed d. functional theory calcns., suggesting nearly all incorporated AQ is made available for charge storage.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1Squ7bM&md5=90e347066809e50539b2e2de56020f51
338
Kong, D.; He, H.; Song, Q.; Wang, B.; Lv, W.; Yang, Q.-H.; Zhi, L. Rational Design of MoS₂@Graphene Nanocables: Towards High Performance Electrode Materials for Lithium Ion Batteries Energy Environ. Sci. 2014, 7, 3320– 3325 DOI: 10.1039/C4EE02211D

Google Scholar

338
Rational design of MoS2@graphene nanocables: towards high performance electrode materials for lithium ion batteries

Kong, Debin; He, Haiyong; Song, Qi; Wang, Bin; Lv, Wei; Yang, Quan-Hong; Zhi, Linjie

Energy & Environmental Science (2014), 7 (10), 3320-3325CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)

Here, we have successfully developed a novel contact mode between MoS2 and graphene, where graphene rolls up into a hollow nanotube and thin MoS2 nanosheets are uniformly standing on the inner surface of graphitic nanotubes, thus forming mech. robust, free-standing, interwoven MoS2@graphene nanocable webs (MoS2@G). Such a hybrid structure can maximize the MoS2 loading in the electrode in which over 90% of MoS2 nanosheets with stacked layer no. of less than 5 can be installed. Remarkably, when calcd. on the basis of the whole electrode, this binder free electrode not only shows high specific capacity (ca. 1150 mA h g-1) and excellent cycling performance (almost 100% capacity retention even after 160 cycles at a c.d. of 0.5 A g-1) but exhibits a surprisingly high-rate capability of 700 mA h g-1 at the rate of 10 A g-1 despite such a high MoS2 loading content, which is one of the best results of MoS2-based electrode materials ever reported thus far.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtlWrt77J&md5=9a459b5666a7d3606a7dde98134859af
339
Yang, S.; Cao, C.; Huang, P.; Peng, L.; Sun, Y.; Wei, F.; Song, W. Sandwich-Like Porous TiO₂/Reduced Graphene Oxide (rGO) for High-Performance Lithium-Ion Batteries J. Mater. Chem. A 2015, 3, 8701– 8705 DOI: 10.1039/C5TA01744K

Google Scholar

339
Sandwich-like porous TiO2/reduced graphene oxide (rGO) for high-performance lithium-ion batteries

Yang, Shuliang; Cao, Changyan; Huang, Peipei; Peng, Li; Sun, Yongbin; Wei, Fang; Song, Weiguo

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (16), 8701-8705CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Sandwich-like porous TiO2/reduced graphene oxide (rGO) composites were prepd. through a facile solvothermal method. These composites with porous structures and high elec. cond. showed high capacity, rate capability and cycling stability when used as an anode electrode material for lithium ion batteries. A reversible capacity of 206 mA h g-1 can be retained at a current rate of 0.1 A g-1 after 200 charge-discharge cycles. Remarkably, a high reversible capacity of ∼128 mA h g-1 at a c.d. of 5 A g-1 can be obtained.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXks1aht70%253D&md5=f9d3ba32270954655275205fe1fac202
340
Ali, G.; Oh, S. H.; Kim, S. Y.; Kim, J. Y.; Cho, B. W.; Chung, K. Y. An Open-Framework Iron Fluoride and Reduced Graphene Oxide Nanocomposite as a High-Capacity Cathode Material for Na-Ion Batteries J. Mater. Chem. A 2015, 3, 10258– 10266 DOI: 10.1039/C5TA00643K

Google Scholar

340
An open-framework iron fluoride and reduced graphene oxide nanocomposite as a high-capacity cathode material for Na-ion batteries

Ali, Ghulam; Oh, Si Hyoung; Kim, Se Young; Kim, Ji Young; Cho, Byung Won; Chung, Kyung Yoon

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (19), 10258-10266CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Cathode materials with high capacity and good stability for rechargeable Na-ion batteries (NIBs) are few in no. Here, a composite is reported of electrochem. active iron fluoride hydrate and reduced graphene oxide (rGO) as a promising cathode material for NIBs. Phase-pure FeF3·0.5H2O is synthesized by a non-aq. pptn. method and a composite with rGO is prepd. to enhance the elec. cond. The encapsulation of FeF3·0.5H2O nanoparticles between the rGO layers results in a lightwt. and stable electrode with a three-dimensional network. The composite material delivers a substantially enhanced discharge capacity of 266 mA h g-1 compared to 158 mA h g-1 of the bare FeF3·0.5H2O at a c.d. of 0.05 C. This composite also shows a stable cycle performance with a high capacity retention of > 86% after 100 cycles, demonstrating its potential as a cathode material for NIBs.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjtFSisbw%253D&md5=22ea89a10b65e3facd89e95f1b2e037b
341
David, L.; Bhandavat, R.; Singh, G. MoS₂/Graphene Composite Paper for Sodium-Ion Battery Electrodes ACS Nano 2014, 8, 1759– 1770 DOI: 10.1021/nn406156b

Google Scholar

341
MoS2/Graphene Composite Paper for Sodium-Ion Battery Electrodes

David, Lamuel; Bhandavat, Romil; Singh, Gurpreet

ACS Nano (2014), 8 (2), 1759-1770CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

We study the synthesis and electrochem. and mech. performance of layered free-standing papers composed of acid-exfoliated few-layer molybdenum disulfide (MoS2) and reduced graphene oxide (rGO) flakes for use as a self-standing flexible electrode in sodium-ion batteries. Synthesis was achieved through vacuum filtration of homogeneous dispersions consisting of varying wt. percent of acid-treated MoS2 flakes in GO in DI water, followed by thermal redn. at elevated temps. The electrochem. performance of the crumpled composite paper (at 4 mg.cm-2) was evaluated as counter electrode against pure Na foil in a half-cell configuration. The electrode showed good Na cycling ability with a stable charge capacity of ∼230 mAh.g-1 with respect to total wt. of the electrode with Coulombic efficiency reaching ∼99%. In addn., static uniaxial tensile tests performed on crumpled composite papers showed high av. strain to failure reaching ∼2%.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXpslejsw%253D%253D&md5=d45da3902a48ed0a91ed1278d69862fb
342
Hu, C.; Zheng, G.; Zhao, F.; Shao, H.; Zhang, Z.; Chen, N.; Jiang, L.; Qu, L. A Powerful Approach to Functional Graphene Hybrids for High Performance Energy-Related Applications Energy Environ. Sci. 2014, 7, 3699– 3708 DOI: 10.1039/C4EE01876A

Google Scholar

342
A powerful approach to functional graphene hybrids for high performance energy-related applications

Hu, Chuangang; Zheng, Guanpei; Zhao, Fei; Shao, Huibo; Zhang, Zhipan; Chen, Nan; Jiang, Lan; Qu, Liangti

Energy & Environmental Science (2014), 7 (11), 3699-3708CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)

Pore-rich graphene networks hold great promise as advanced supporting materials of metals and metal oxides for high electrochem. performance. In this work, a dual substrate-assisted redn. and assembly (DSARA) process has been devised and demonstrated as a general approach for the spontaneous redn. of graphene oxide, well-organized assembly of reduced graphene oxide into three-dimensional porous networks, and simultaneous functionalization of graphenes with metal-based nanocomponents on demand, including metals, metal oxides, metal/metal oxide hybrids or alloys. The newly designed process avoids the use of toxic reducing agents, multiple steps, and long reaction times, and offers a facile but powerful pathway to greatly enhance the merits of using pristine graphenes in energy-related applications such as lithium ion batteries, fuel cells, photoelec. conversion devices, and so on. Specifically, as an anode material in a lithium ion battery (LIB), the DSARA-produced RGO decorated with NiO/Ni nanohybrids presents a record capacity with a high charge-discharge rate compared to those reported so far for Ni based materials. PdPt alloy nanoparticles on 3D RGO generated by DSARA exhibits a highly efficient catalytic performance for the oxygen redn. reaction (ORR) in fuel cells.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtlOjsLbJ&md5=fdd357d50ca23d3d62e66231005ddf95
343
Ren, X.; Hu, Z.; Hu, H.; Qiang, R.; Li, L.; Li, Z.; Yang, Y.; Zhang, Z.; Wu, H. Noncovalently-Functionalized Reduced Graphene Oxide Sheets by Water-Soluble Methyl Green for Supercapacitor Application Mater. Res. Bull. 2015, 70, 215– 221 DOI: 10.1016/j.materresbull.2015.04.045

Google Scholar

343
Noncovalently-functionalized reduced graphene oxide sheets by water-soluble methyl green for supercapacitor application

Ren, Xiaoying; Hu, Zhongai; Hu, Haixiong; Qiang, Ruibin; Li, Li; Li, Zhimin; Yang, Yuying; Zhang, Ziyu; Wu, Hongying

Materials Research Bulletin (2015), 70 (), 215-221CODEN: MRBUAC; ISSN:0025-5408. (Elsevier Ltd.)

In the present work, water-sol. electroactive methyl green (MG) has been used to non-covalently functionalize reduced graphene oxide (RGO) for enhancing supercapacitive performance. The microstructure, compn. and morphol. of MG-RGO composites are systematically characterized by UV-vis absorption, field emission SEM (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochem. performances are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochem. impedance spectroscopy (EIS). The fast redox reactions from MG could generate addnl. pseudocapacitance, which endows RGO higher capacitances. As a result, the MG-RGO composite (with the 5:4 mass ratio of MG:RGO) achieve a max. value of 341 F g-1 at 1 A g-1 within the potential range from -0.25 to 0.75 V and provide a 180% enhancement in specific capacitance in comparison with pure RGO. Furthermore, excellent rate capability (72% capacitance retention from 1 A g-1 to 20 A g-1) and long life cycle (12% capacitance decay after 5000 cycles) are achieved for the MG-RGO composite electrode.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXntFGrsb8%253D&md5=7b9ed34edeb221e7019e3bca5efb24ef
344
Jung, S. M.; Mafra, D. L.; Lin, C.-T.; Jung, H. Y.; Kong, J. Controlled Porous Structures of Graphene Aerogels and Their Effect on Supercapacitor Performance Nanoscale 2015, 7, 4386– 4393 DOI: 10.1039/C4NR07564A

Google Scholar

344
Controlled porous structures of graphene aerogels and their effect on supercapacitor performance

Jung, Sung Mi; Mafra, Daniela Lopes; Lin, Cheng-Te; Jung, Hyun Young; Kong, Jing

Nanoscale (2015), 7 (10), 4386-4393CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

The design and optimization of 3D graphene nanostructures are critically important since the properties of electrochem. energy storages such as supercapacitors can be dramatically enhanced by tunable porous channels. In this work, we have developed porous graphene aerogels from graphene suspensions obtained via electrochem. exfoliation and explored their application as supercapacitor electrodes. By adjusting the content of the electrolyte in the exfoliation process, the aspect ratio of graphene sheets and the porosity of the graphene network can be optimized. Furthermore, the freezing temp. in the freeze drying step is also found to play a crit. role in the resulting pore size distributions of the porous networks. The optimized conditions lead to meso- and macroporous graphene aerogels with a high sp. surface area, extremely low densities and superior elec. properties. As a result, the graphene aerogel supercapacitors exhibit a specific capacitance of 325 F g-1 at 1 A g-1 and an energy d. of 45 Wh kg-1 in a 0.5 M H2SO4 aq. electrolyte with high electrochem. stability and electrode uniformity required for practical usage. This research provides a practical method for lightwt., high-performance and low-cost materials in the effective use of energy storage systems.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXislCjtrk%253D&md5=b777202fe404a63c52d9a6b0c3b0a30c
345
Jana, M.; Saha, S.; Khanra, P.; Samanta, P.; Koo, H.; Murmu, N. C.; Kuila, T. Non-Covalent Functionalization of Reduced Graphene Oxide Using Sulfanilic Acid Azocromotrop and Its Application as a Supercapacitor Electrode Material J. Mater. Chem. A 2015, 3, 7323– 7331 DOI: 10.1039/C4TA07009G

Google Scholar

345
Non-covalent functionalization of reduced graphene oxide using sulfanilic acid azocromotrop and its application as a supercapacitor electrode material

Jana, Milan; Saha, Sanjit; Khanra, Partha; Samanta, Pranab; Koo, Hyeyoung; Chandra Murmu, Naresh; Kuila, Tapas

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (14), 7323-7331CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Sulfanilic acid azocromotrop (SAC) modified reduced graphene oxide (SAC-RGO) was prepd. by simple noncovalent functionalization of graphene oxide (GO) followed by post redn. using hydrazine monohydrate. Spectral anal. (FTIR, Raman and XPS) revealed that successful modification had occurred of GO with SAC through π-π interaction. The elec. cond. of SAC-RGO is ∼551 S m-1. The capacitive performance of SAC-RGO was recorded using a three electrode set up with 1 (M) aq. H2SO4 as the electrolyte. The -SO3H functionalities of SAC contributed pseudocapacitance as evidenced from the redox peaks (at ∼0.43 and 0.27 V) present in the cyclic voltammetric (CV) curves measured for SAC-RGO. The contribution of elec. double layer capacitance was evidenced from the near rectangular shaped CV curves and resulted in a high specific capacitance of 366 F g-1 at a c.d. of 1.2 A g-1 for SAC-RGO electrode. An asym. device (SAC-RGO//RGO) was designed with SAC-RGO as the pos. electrode and RGO as the neg. electrode. The device showed an energy d. of ∼25.8 W h kg-1 at a power d. of ∼980 W kg-1. The asym. device showed retention in specific capacitance of ∼72% after 5000 charge-discharge cycles. The Nyquist data of the device was fitted with Z-view and different components (soln. resistance, charge-transfer resistance and Warburg elements) were calcd. from the fitted curves.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjt1SksLg%253D&md5=1b356ff31927777e6f79f31d2921d7e4
346
Hsu, W.-T.; Tsai, Z.-S.; Chen, L.-C.; Chen, G.-Y.; Lin, C.-C.; Chen, M.-H.; Song, J.-M.; Lin, C.-H. Passivation Ability of Graphene Oxide Demonstrated by Two-Different-Metal Solar Cells Nanoscale Res. Lett. 2014, 9, 696 DOI: 10.1186/1556-276X-9-696

Google Scholar

There is no corresponding record for this reference.
347
Kim, K. S.; Zhao, Y.; Jang, H.; Lee, S. Y.; Kim, J. M.; Kim, K. S.; Ahn, J.-H.; Kim, P.; Choi, J.-Y.; Hong, B. H. Large-Scale Pattern Growth of Graphene Films for Stretchable Transparent Electrodes Nature 2009, 457, 706– 710 DOI: 10.1038/nature07719

Google Scholar

347
Large-scale pattern growth of graphene films for stretchable transparent electrodes

Kim, Keun Soo; Zhao, Yue; Jang, Houk; Lee, Sang Yoon; Kim, Jong Min; Kim, Kwang S.; Ahn, Jong-Hyun; Kim, Philip; Choi, Jae-Young; Hong, Byung Hee

Nature (London, United Kingdom) (2009), 457 (7230), 706-710CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)

Problems assocd. with large-scale pattern growth of graphene constitute one of the main obstacles to using this material in device applications. Recently, macroscopic-scale graphene films were prepd. by two-dimensional assembly of graphene sheets chem. derived from graphite crystals and graphene oxides. However, the sheet resistance of these films was found to be much larger than theor. expected values. Here we report the direct synthesis of large-scale graphene films using chem. vapor deposition on thin nickel layers, and present two different methods of patterning the films and transferring them to arbitrary substrates. The transferred graphene films show very low sheet resistance of ∼280 Ω per square, with ∼80% optical transparency. At low temps., the monolayers transferred to silicon dioxide substrates show electron mobility greater than 3,700 cm2 V-1 s-1 and exhibit the half-integer quantum Hall effect, implying that the quality of graphene grown by chem. vapor deposition is as high as mech. cleaved graphene. Employing the outstanding mech. properties of graphene, we also demonstrate the macroscopic use of these highly conducting and transparent electrodes in flexible, stretchable, foldable electronics.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXht1ehtL4%253D&md5=0eef5b83d20b2e74add31eb1aa19337e
348
Yin, Z.; Zhu, J.; He, Q.; Cao, X.; Tan, C.; Chen, H.; Yan, Q.; Zhang, H. Graphene-Based Materials for Solar Cell Applications Adv. Energy Mater. 2014, 4, 1300574 DOI: 10.1002/aenm.201300574

Google Scholar

348
Graphene-Based Materials for Solar Cell Applications

Yin, Zongyou; Zhu, Jixin; He, Qiyuan; Cao, Xiehong; Tan, Chaoliang; Chen, Hongyu; Yan, Qingyu; Zhang, Hua

Advanced Energy Materials (2014), 4 (1), 1300574/1-1300574/19CODEN: ADEMBC; ISSN:1614-6840. (Wiley-Blackwell)

A review. Graphene has attracted increasing attention due to its unique elec., optical, optoelectronic, and mech. properties, which have opened up huge nos. of opportunities for applications. An overview of the recent research on graphene and its derivs. is presented, with a particular focus on synthesis, properties, and applications in solar cells.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjt1ahug%253D%253D&md5=d8690f67136e7320b8dec889321ceb96
349
Liu, J.; Xue, Y.; Dai, L. Sulfated Graphene Oxide as a Hole-Extraction Layer in High-Performance Polymer Solar Cells J. Phys. Chem. Lett. 2012, 3, 1928– 1933 DOI: 10.1021/jz300723h

Google Scholar

349
Sulfated Graphene Oxide as a Hole-Extraction Layer in High-Performance Polymer Solar Cells

Liu, Jun; Xue, Yuhua; Dai, Liming

Journal of Physical Chemistry Letters (2012), 3 (14), 1928-1933CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)

In this study, we have rationally designed and successfully developed sulfated graphene oxide (GO-OSO3H) with -OSO3H groups attached to the carbon basal plane of reduced GO surrounded with edge-functionalized -COOH groups. The resultant GO-OSO3H is demonstrated to be an excellent hole extn. layer for polymer solar cells because of its proper work function for ohmic contact with the donor polymer, its reduced basal plane for improving cond., and its -OSO3H/-COOH groups for enhancing soly. for soln. processing. Compared with that of GO, the much improved cond. of GO-OSO3H (1.3 S/m vs. 0.004 S/m) leads to greatly improved fill factor (0.71 vs. 0.58) and power conversion efficiency (4.37% vs. 3.34%) of the resulting polymer solar cell devices. Moreover, the device performance of GO-OSO3H is among the best reported for intensively studied poly(3-hexylthiophene):[6,6]-phenyl-C61 butyric acid Me ester (P3HT:PCBM) devices. Our results imply that judiciously functionalized graphene materials can be used to replace existing hole extn. layer materials for specific device applications with outstanding performance.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XpsVGktb8%253D&md5=b2d93521cbf46d9556445c22f01b3910
350
Shi, E.; Li, H.; Yang, L.; Zhang, L.; Li, Z.; Li, P.; Shang, Y.; Wu, S.; Li, X.; Wei, J. Colloidal Antireflection Coating Improves Graphene-Silicon Solar Cells Nano Lett. 2013, 13, 1776– 1781

Google Scholar

350
Colloidal antireflection coating improves graphene-silicon solar cells

Shi, Enzheng; Li, Hongbian; Yang, Long; Zhang, Luhui; Li, Zhen; Li, Peixu; Shang, Yuanyuan; Wu, Shiting; Li, Xinming; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai; Fang, Ying; Cao, Anyuan

Nano Letters (2013), 13 (4), 1776-1781CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Carbon nanotube-Si and graphene-Si solar cells have attracted much interest recently owing to their potential in simplifying manufg. process and lowering cost compared to Si cells. Until now, the power conversion efficiency of graphene-Si cells remains under 10% and well below that of the nanotube-Si counterpart. Here, we involved a colloidal antireflection coating onto a monolayer graphene-Si solar cell and enhanced the cell efficiency to 14.5% under std. illumination (air mass 1.5, 100 mW/cm2) with a stable antireflection effect over long time. The antireflection treatment was realized by a simple spin-coating process, which significantly increased the short-circuit c.d. and the incident photon-to-electron conversion efficiency to about 90% across the visible range. Our results demonstrate a great promise in developing high-efficiency graphene-Si solar cells in parallel to the more extensively studied carbon nanotube-Si structures.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXksVyjtro%253D&md5=205bcc03a483f0311f97e4ca17b2543c
351
Wang, J. T.-W.; Ball, J. M.; Barea, E. M.; Abate, A.; Alexander-Webber, J. A.; Huang, J.; Saliba, M.; Mora-Sero, I.; Bisquert, J.; Snaith, H. J. Low-Temperature Processed Electron Collection Layers of Graphene/TiO₂ Nanocomposites in Thin Film Perovskite Solar Cells Nano Lett. 2014, 14, 724– 730 DOI: 10.1021/nl403997a

Google Scholar

351
Low-Temperature Processed Electron Collection Layers of Graphene/TiO2 Nanocomposites in Thin Film Perovskite Solar Cells

Wang, Jacob Tse-Wei; Ball, James M.; Barea, Eva M.; Abate, Antonio; Alexander-Webber, Jack A.; Huang, Jian; Saliba, Michael; Mora-Sero, Ivan; Bisquert, Juan; Snaith, Henry J.; Nicholas, Robin J.

Nano Letters (2014), 14 (2), 724-730CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

The highest efficiencies in soln.-processable perovskite-based solar cells were achieved using an electron collection layer that requires sintering at 500°. This is unfavorable for low-cost prodn., applications on plastic substrates, and multijunction device architectures. Here we report a low-cost, soln.-based deposition procedure utilizing nanocomposites of graphene and TiO2 nanoparticles as the electron collection layers in meso-superstructured perovskite solar cells. The graphene nanoflakes provide superior charge-collection in the nanocomposites, enabling the entire device to be fabricated at temps. no higher than 150°. These solar cells show remarkable photovoltaic performance with a power conversion efficiency up to 15.6%. This work demonstrates that graphene/metal oxide nanocomposites have the potential to contribute significantly toward the development of low-cost solar cells.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvFejtLzO&md5=9ffbefc7f6b685213e328c6e0bc03930
352
Kim, H.; Mattevi, C.; Kim, H. J.; Mittal, A.; Mkhoyan, K. A.; Riman, R. E.; Chhowalla, M. Optoelectronic Properties of Graphene Thin Films Deposited by a Langmuir-Blodgett Assembly Nanoscale 2013, 5, 12365– 12374 DOI: 10.1039/c3nr02907g

Google Scholar

352
Optoelectronic properties of graphene thin films deposited by a Langmuir-Blodgett assembly

Kim, HoKwon; Mattevi, Cecilia; Kim, Hyun Jun; Mittal, Anudha; Mkhoyan, K. Andre; Riman, Richard E.; Chhowalla, Manish

Nanoscale (2013), 5 (24), 12365-12374CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

Large area thin films of few-layered unfunctionalized graphene platelets are developed with fine control over the thickness. The thin films are obtained by a Langmuir-Blodgett assembly at the interface of graphene soln. in N-methyl-2-pyrrolidone (NMP) and water, and their optoelectronic properties and conduction mechanism are investigated in relation to lateral flake size and thin film thickness. The elec. cond. and carrier mobility are affected by the flake size (200 nm to 1 μm) and by the packing of the nanostructure platelet network. General effective medium theory is used to explain the thickness dependent cond. and to det. the percolation threshold film thickness which was found to be about 10 nm (at a vol. fraction of ∼39%) for a Langmuir-Blodgett film of an av. platelet lateral size of 170 ± 40 nm. The electronic behavior of the material shows more similarities with polycryst. turbostratic graphite than thin films of reduced graphene oxide, carbon nanotubes, or disordered conducting polymers. While in these systems the conduction mechanism is often dominated by the presence of an energy barrier between conductive and non-conductive regions in the network, in the exfoliated graphene networks the conduction mechanism can be explained by the simple two-band model which is characteristic of polycryst. graphite.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvVejurbI&md5=9775bedf8d82d1c5424deda2f8402183
353
Supur, M.; Ohkubo, K.; Fukuzumi, S. Photoinduced Charge Separation in Ordered Self-Assemblies of Perylenediimide-Graphene Oxide Hybrid Layers Chem. Commun. 2014, 50, 13359– 13361 DOI: 10.1039/C4CC05694A

Google Scholar

There is no corresponding record for this reference.
354
Dehsari, H. S.; Shalamzari, E. K.; Gavgani, J. N.; Taromi, F. A.; Ghanbary, S. Efficient Preparation of Ultralarge Graphene Oxide Using a PEDOT:PSS/GO Composite Layer as Hole Transport Layer in Polymer-Based Optoelectronic Devices RSC Adv. 2014, 4, 55067– 55076 DOI: 10.1039/C4RA09474C

Google Scholar

354
Efficient preparation of ultralarge graphene oxide using a PEDOT:PSS/GO composite layer as hole transport layer in polymer-based optoelectronic devices

Dehsari, Hamed Sharifi; Shalamzari, Elham Khodabakhshi; Gavgani, Jaber Nasrollah; Taromi, Faramarz Afshar; Ghanbary, Shima

RSC Advances (2014), 4 (98), 55067-55076CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)

We herein report an investigation of ultralarge graphene oxide (UL-GO) sheet/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin composite layers fabricated by spin coating on an indium-tin-oxide (ITO) anode as hole transport layer (HTL) in polymer light-emitting diodes (PLEDs), as well as polymer solar cells (PSCs). Monolayer UL-GOs were first synthesized based on a novel soln.-phase method involving pre-exfoliation of graphite flakes which were then mixed into the PEDOT:PSS soln. in various specific amts. The PEDOT:PSS composite film mixed with 0.04 wt% UL-GO by wt. exhibits a cond. of 749.4 S cm-1 and a transmittance of 88.6% at 550 nm. The PEDOT:PSS/GO HTL shows enhanced charge carrier transport because of improved cond. by the weakening of the coulombic attraction between PEDOT and PSS by the functional groups on GO nanosheets, and the formation of an extended conductive network. Moreover, it can effectively block electrons and reduce resistance in the HTL, leading to better injection and transport of holes and lower turn-on voltage and resulting in a higher overall efficiency in PLEDs. Similarly, it remarkably increases the short circuit current (Jsc), and PSC efficiency because of a remarkable redn. of exciton quenching that results in higher charge extn. in PSCs. The optimized PLEDs and PSCs with a PEDOT:PSS/GO composite HTL layer show a max. luminosity of 725.6 cd m-2 (at 10.6 V) for PLEDs, as well as a power conversion efficiency of 3.388% for PSCs, which were improved by ∼11% and 12%, resp., compared to ref. PLEDs and PSCs with a PEDOT:PSS layer.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVWmu7fM&md5=a1dc1d1b44a0e052fa9dd958a6012aa6
355
Kymakis, E.; Savva, K.; Stylianakis, M. M.; Fotakis, C.; Stratakis, E. Flexible Organic Photovoltaic Cells with In Situ Nonthermal Photoreduction of Spin-Coated Graphene Oxide Electrodes Adv. Funct. Mater. 2013, 23, 2742– 2749 DOI: 10.1002/adfm.201202713

Google Scholar

355
Flexible Organic Photovoltaic Cells with In Situ Nonthermal Photoreduction of Spin-Coated Graphene Oxide Electrodes

Kymakis, Emmanuel; Savva, Kyriaki; Stylianakis, Minas M.; Fotakis, Costas; Stratakis, Emmanuel

Advanced Functional Materials (2013), 23 (21), 2742-2749CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

The first redn. methodol., compatible with flexible, temp.-sensitive substrates, for the prodn. of reduced spin-coated graphene oxide (GO) electrodes is reported. It is based on the use of a laser beam for the in situ, non-thermal, redn. of spin-coated GO films on flexible substrates over a large area. The photoredn. process is one-step, facile, and is rapidly carried out at room temp. in air without affecting the integrity of the graphene lattice or the flexibility of the underlying substrate. Conductive graphene films with a sheet resistance of as low as 700 Ω sq-1 and transmittance of 44% can be obtained, much higher than can be achieved for flexible layers reduced by chem. means. As a proof of concept of the technique, laser-reduced GO (LrGO) films are utilized as transparent electrodes in flexible, bulk heterojunction, org. photovoltaic (OPV) devices, replacing the traditional ITO. The devices displayed a power-conversion efficiency of 1.1%, which is the highest reported so far for OPV device incorporating reduced GO as the transparent electrode. The in situ non-thermal photoredn. of spin-coated GO films creates a new way to produce flexible functional graphene electrodes for a variety of electronic applications in a process that carries substantial promise for industrial implementation.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXkvFCktw%253D%253D&md5=460633f56a0bb5b9f117153340e8820f
356
Oregan, B.; Gratzel, M. A Low-Cost, High-Efficiency Solar Cell Based on Dye-Sensitized Colloidal TiO₂ Films Nature 1991, 353, 737– 740 DOI: 10.1038/353737a0

Google Scholar

356
A low-cost, high-efficiency solar cell based on dye-sensitized colloidal titanium dioxide films

O'Regan, Brian; Graetzel, Michael

Nature (London, United Kingdom) (1991), 353 (6346), 737-40CODEN: NATUAS; ISSN:0028-0836.

A photoelectrochem. cell was fabricated from low- to medium-purity materials through low-cost processes, which exhibits a com. realistic energy-conversion efficiency. The device is based on a 10-μm-thick, optically transparent film of TiO2 particles, coated with a monolayer of a charge-transfer dye to sensitize the film for light harvesting. The device harvests a high proportion of the incident solar energy flux (46%) and shows exceptionally high efficiencies for the conversion of incident photons to elec. current (>80%). The overall light-to-elec. energy conversion yield is 7.1-8.9% in simulated solar light and 12% in diffuse daylight. The c.d. >12 mA/cm2 and exceptional stability (sustaining ≥5 million turnover without decompn.), and low cost, make practical applications feasible.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38XoslOn&md5=02ea66126c0eea94a36e942139157b0f
357
Hagfeldt, A.; Boschloo, G.; Sun, L.; Kloo, L.; Pettersson, H. Dye-Sensitized Solar Cells Chem. Rev. 2010, 110, 6595– 6663 DOI: 10.1021/cr900356p

Google Scholar

357
Dye-Sensitized Solar Cells

Hagfeldt, Anders; Boschloo, Gerrit; Sun, Licheng; Kloo, Lars; Pettersson, Henrik

Chemical Reviews (Washington, DC, United States) (2010), 110 (11), 6595-6663CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)

A review on dye-sensitized solar cells (DSCs). Some brief notes on solar energy in general and DSC in particular are given, followed by a discussion of the operational principles of DSC (energetics and kinetics). Then, the development of material components and some specific exptl. techniques to characterize DSC are described. The current status of module development is also discussed, and finally a brief future outlook is given.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtFChs77M&md5=e6727377e1d3eec4c6c6d78276ff77a1
358
Cheng, G.; Akhtar, M. S.; Yang, O. B.; Stadler, F. J. Novel Preparation of Anatase TiO₂@Reduced Graphene Oxide Hybrids for High-Performance Dye-Sensitized Solar Cells ACS Appl. Mater. Interfaces 2013, 5, 6635– 6642 DOI: 10.1021/am4013374

Google Scholar

358
Novel Preparation of Anatase TiO2@Reduced Graphene Oxide Hybrids for High-Performance Dye-Sensitized Solar Cells

Cheng, Gang; Akhtar, M. Shaheer; Yang, O-Bong; Stadler, Florian J.

ACS Applied Materials & Interfaces (2013), 5 (14), 6635-6642CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

An effective method was developed to prep. hybrid materials of TiO2 nanoparticles on reduced graphene oxide (RGO) sheets for application in solar cells. The morphol., size, and crystal phase of the TiO2 nanoparticles and TiO2@reduced graphene oxide (TiO2@RGO) hybrids were investigated in detail by X-ray diffraction (XRD), SEM, transmission electron microscopy (TEM), selected area electron diffraction (SAED), XPS, Raman, and UV-vis diffuse reflectance spectroscopy. A possible growth mechanism of TiO2@RGO hybrids is proposed based on observations of the TiO2 nanoparticles obtained from the hydrolysis process under different conditions. The effects of different reduced graphene oxide contents on the energy conversion efficiency of the dye-sensitized solar cells (DSSCs) based on J-V and incident photon-to-current conversion efficiency (IPCE) spectra are also discussed. DSSCs based on TiO2@RGO hybrid photoanodes with a graphene content of 1.6 wt % showed an overall light-to-electricity conversion efficiency of 7.68%, which is much higher than that of pure anatase nanoparticles (4.78%) accompanied by a short-circuit c.d. of 18.39 mA cm2, an open-circuit voltage of 0.682 V, and a fill factor of 61.2%.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXpsFGktbw%253D&md5=856f37f5b06005fe85bb5e283a63a5e2
359
Bi, E.; Chen, H.; Yang, X.; Peng, W.; Graetzel, M.; Han, L. A Quasi Core-Shell Nitrogen-Doped Graphene/Cobalt Sulfide Conductive Catalyst for Highly Efficient Dye-Sensitized Solar Cells Energy Environ. Sci. 2014, 7, 2637– 2641 DOI: 10.1039/C4EE01339E

Google Scholar

There is no corresponding record for this reference.
360
Yang, W. S.; Noh, J. H.; Jeon, N. J.; Kim, Y. C.; Ryu, S.; Seo, J.; Seok, S. I. High-Performance Photovoltaic Perovskite Layers Fabricated through Intramolecular Exchange Science 2015, 348, 1234– 1237 DOI: 10.1126/science.aaa9272

Google Scholar

360
High-performance photovoltaic perovskite layers fabricated through intramolecular exchange

Yang, Woon Seok; Noh, Jun Hong; Jeon, Nam Joong; Kim, Young Chan; Ryu, Seungchan; Seo, Jangwon; Seok, Sang Il

Science (Washington, DC, United States) (2015), 348 (6240), 1234-1237CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

The band gap of formamidinium lead iodide (FAPbI3) perovskites allows broader absorption of the solar spectrum relative to conventional methylammonium lead iodide (MAPbI3). Because the optoelectronic properties of perovskite films are closely related to film quality, deposition of dense and uniform films is crucial for fabricating high-performance perovskite solar cells (PSCs). An approach is reported for depositing high-quality FAPbI3 films, involving FAPbI3 crystn. by the direct intramol. exchange of dimethylsulfoxide (DMSO) mols. intercalated in PbI2 with formamidinium iodide. This process produces FAPbI3 films with (111)-preferred crystallog. orientation, large-grained dense microstructures, and flat surfaces without residual PbI2. Using films prepd. by this technique, the FAPbI3-based PSCs are fabricated with max. power conversion efficiency greater than 20%.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXps1OltL0%253D&md5=f3f3e002b2ff01a20b09eb6cab4cc0c5
361
Jeon, N. J.; Noh, J. H.; Yang, W. S.; Kim, Y. C.; Ryu, S.; Seo, J.; Seok, S. I. Compositional Engineering of Perovskite Materials for High-Performance Solar Cells Nature 2015, 517, 476– 480 DOI: 10.1038/nature14133

Google Scholar

361
Compositional engineering of perovskite materials for high-performance solar cells

Jeon, Nam Joong; Noh, Jun Hong; Yang, Woon Seok; Kim, Young Chan; Ryu, Seungchan; Seo, Jangwon; Seok, Sang Il

Nature (London, United Kingdom) (2015), 517 (7535), 476-480CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)

Here we combine the promising, owing to its comparatively narrow bandgap, but relatively unstable formamidinium lead iodide (FAPbI3) with methylammonium lead bromide (MAPbBr3) as the light-harvesting unit in a bilayer solar cell architecture. We investigated phase stability, morphol. of the perovskite layer, hysteresis in current-voltage characteristics, and overall performance as a function of chem. compn. Our results show that incorporation of MAPbBr3 into FAPbI3 stabilizes the perovskite phase of FAPbI3 and improves the power conversion efficiency of the solar cell to >18% under a std. illumination of 100 mW/cm2. These findings further emphasize the versatility and performance potential of inorg.-org. lead halide perovskite materials for photovoltaic applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXivF2msg%253D%253D&md5=6b63487cbd6ca18ba27638ae8887c711
362
Kong, D.; Wang, H.; Cha, J. J.; Pasta, M.; Koski, K. J.; Yao, J.; Cui, Y. Synthesis of MoS₂ and MoSe₂ Films with Vertically Aligned Layers Nano Lett. 2013, 13, 1341– 1347 DOI: 10.1021/nl400258t

Google Scholar

362
Synthesis of MoS2 and MoSe2 Films with Vertically Aligned Layers

Kong, Desheng; Wang, Haotian; Cha, Judy J.; Pasta, Mauro; Koski, Kristie J.; Yao, Jie; Cui, Yi

Nano Letters (2013), 13 (3), 1341-1347CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Layered materials consist of mol. layers stacked together by weak interlayer interactions. They often crystallize to form atomically smooth thin films, nanotubes, and platelet or fullerene-like nanoparticles due to the anisotropic bonding. Structures that predominately expose edges of the layers exhibit high surface energy and are often considered unstable. The authors present a synthesis process to grow MoS2 and MoSe2 thin films with vertically aligned layers, thereby maximally exposing the edges on the film surface. Such edge-terminated films are metastable structures of MoS2 and MoSe2, which may find applications in diverse catalytic reactions. The authors confirmed their catalytic activity in a hydrogen evolution reaction (HER), in which the exchange c.d. correlates directly with the d. of the exposed edge sites.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXitFajsLY%253D&md5=12750e01fd7cb5c14b79f2c6168d02b0
363
Wang, H.; Kong, D.; Johanes, P.; Cha, J. J.; Zheng, G.; Yan, K.; Liu, N.; Cui, Y. MoSe₂ and WSe₂ Nanofilms with Vertically Aligned Molecular Layers on Curved and Rough Surfaces Nano Lett. 2013, 13, 3426– 3433 DOI: 10.1021/nl401944f

Google Scholar

363
MoSe2 and WSe2 Nanofilms with Vertically Aligned Molecular Layers on Curved and Rough Surfaces

Wang, Haotian; Kong, Desheng; Johanes, Petr; Cha, Judy J.; Zheng, Guangyuan; Yan, Kai; Liu, Nian; Cui, Yi

Nano Letters (2013), 13 (7), 3426-3433CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

Two-dimensional (2D) layered materials exhibit high anisotropy in material properties due to the large difference of intra- and interlayer bonding. This presents opportunities to engineer materials whose properties strongly depend on the orientation of the layers relative to the substrate. Using a similar growth process reported in their previous study of MoS2 and MoSe2 films whose layers were oriented vertically on flat substrates, the authors demonstrate that the vertical layer orientation can be realized on curved and rough surfaces such as nanowires (NWs) and microfibers. Such structures can increase the surface area while maintaining the perpendicular orientation of the layers, which may be useful in enhancing various catalytic activities. Vertically aligned MoSe2 and WSe2 nanofilms on Si NWs and carbon fiber paper are presented. The MoSe2 and WSe2 nanofilms on carbon fiber paper are highly efficient electrocatalysts for hydrogen evolution reaction (HER) compared with flat substrates. Both materials exhibit extremely high stability in acidic soln. as the HER catalytic activity shows no degrdn. after 15,000 continuous potential cycles. The HER activity of MoSe2 is further improved by Ni doping.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtVWhurfE&md5=25f2bdf006d4556ce0f93f0df121cf8c
364
Chen, W. F.; Wang, C. H.; Sasaki, K.; Marinkovic, N.; Xu, W.; Muckerman, J. T.; Zhu, Y.; Adzic, R. R. Highly Active and Durable Nanostructured Molybdenum Carbide Electrocatalysts for Hydrogen Production Energy Environ. Sci. 2013, 6, 943– 951 DOI: 10.1039/c2ee23891h

Google Scholar

364
Highly active and durable nanostructured molybdenum carbide electrocatalysts for hydrogen production

Chen, W.-F.; Wang, C.-H.; Sasaki, K.; Marinkovic, N.; Xu, W.; Muckerman, J. T.; Zhu, Y.; Adzic, R. R.

Energy & Environmental Science (2013), 6 (3), 943-951CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)

In an attempt to tailor low-cost, precious-metal-free electrocatalysts for water electrolysis in acid, molybdenum carbide (β-Mo2C) nanoparticles are prepd. by in situ carburization of ammonium molybdate on carbon nanotubes and XC-72R carbon black without using any gaseous carbon source. The formation of Mo2C is investigated by thermogravimetry and in situ X-ray diffraction. X-ray absorption anal. reveals that Mo2C nanoparticles are inlaid or anchored into the carbon supports, and the electronic modification makes the surface exhibit a relatively moderate Mo-H bond strength. It is found that carbon nanotube-supported Mo2C showed superior electrocatalytic activity and stability in the hydrogen evolution reaction (HER) compared to the bulk Mo2C. An overpotential of 63 mV for driving 1 mA cm-2 of c.d. was measured for the nanotube-supported Mo2C catalysts; this exceeds the activity of analogous Mo2C catalysts. The enhanced electrochem. activity is facilitated by unique effects of the anchored structure coupled with the electronic modification.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXivVGktro%253D&md5=99a1c039221fb31d192a4a35a70eeff3
365
Vrubel, H.; Hu, X. Molybdenum Boride and Carbide Catalyze Hydrogen Evolution in both Acidic and Basic Solutions Angew. Chem., Int. Ed. 2012, 51, 12703– 12706 DOI: 10.1002/anie.201207111

Google Scholar

365
Molybdenum Boride and Carbide Catalyze Hydrogen Evolution in both Acidic and Basic Solutions

Vrubel, Heron; Hu, Xile

Angewandte Chemie, International Edition (2012), 51 (51), 12703-12706CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

MoB and Mo2C particles are excellent catalysts for hydrogen evolution in acidic and basic solns. The catalysts are stable during an electrolysis with exemption of MoB at pH 14. The activity in alk. solns. is surprising high and is comparable to that in acidic solns. The molybdenum boride and carbide were pressed onto a soft carbon paste electrodes with reasonably high loading. The possible reaction mechanism of hydrogen formation is briefly discussed.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1GgsrbN&md5=e7481bc3202e36d6c6eaf7a06daeab2f
366
Karunadasa, H. I.; Montalvo, E.; Sun, Y.; Majda, M.; Long, J. R.; Chang, C. J. A Molecular MoS₂ Edge Site Mimic for Catalytic Hydrogen Generation Science 2012, 335, 698– 702 DOI: 10.1126/science.1215868

Google Scholar

366
A Molecular MoS2 Edge Site Mimic for Catalytic Hydrogen Generation

Karunadasa, Hemamala I.; Montalvo, Elizabeth; Sun, Yujie; Majda, Marcin; Long, Jeffrey R.; Chang, Christopher J.

Science (Washington, DC, United States) (2012), 335 (6069), 698-702CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

Inorg. solids are an important class of catalysts that often derive their activity from sparse active sites that are structurally distinct from the inactive bulk. Rationally optimizing activity is therefore beholden to the challenges in studying these active sites in mol. detail. Here, we report a mol. that mimics the structure of the proposed triangular active edge site fragments of molybdenum disulfide (MoS2), a widely used industrial catalyst that has shown promise as a low-cost alternative to platinum for electrocatalytic hydrogen prodn. By leveraging the robust coordination environment of a pentapyridyl ligand, we synthesized and structurally characterized a well-defined MoIV-disulfide complex that, upon electrochem. redn., can catalytically generate hydrogen from acidic org. media as well as from acidic water.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhvVCjsr8%253D&md5=66849a25acaecaf60e1922de5397b061
367
Chen, W.-F.; Sasaki, K.; Ma, C.; Frenkel, A. I.; Marinkovic, N.; Muckerman, J. T.; Zhu, Y.; Adzic, R. R. Hydrogen-Evolution Catalysts Based on Non-Noble Metal Nickel-Molybdenum Nitride Nanosheets Angew. Chem., Int. Ed. 2012, 51, 6131– 6135 DOI: 10.1002/anie.201200699

Google Scholar

367
Hydrogen-Evolution Catalysts Based on Non-Nobel Metal Nickel-Molybdenum Nitride Nanosheets

Chen, Wei-Fu; Sasaki, Kotaro; Ma, Chao; Frenkel, Anatoly I.; Marinkovic, Nebojsa; Muckerman, James T.; Zhu, Yimei; Adzic, Radoslav R.

Angewandte Chemie, International Edition (2012), 51 (25), 6131-6135, S6131/1-S6131/12CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

The heterogeneous electrocatalytic hydrogen-evolving system was created from earth-abundant and inexpensive components. The NiMoNx/C catalyst exhibited an excellent activity for the HER with a small overpotential of 78 mV, a high exchange current and a Tafel slope as small as 35 mVdec-1. In acidic solns. the catalyst can be used without noticeable corrosion. The XANES results provided an approach to understand electronic properties and the stabilizing effect on nitrogen on metallic states of nickel and molybdenum.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xms1ekt7Y%253D&md5=fc19864cc8d06336216a1d8acfb15008
368
Cao, B.; Veith, G. M.; Neuefeind, J. C.; Adzic, R. R.; Khalifah, P. G. Mixed Close-Packed Cobalt Molybdenum Nitrides as Non-noble Metal Electrocatalysts for the Hydrogen Evolution Reaction J. Am. Chem. Soc. 2013, 135, 19186– 19192 DOI: 10.1021/ja4081056

Google Scholar

368
Mixed Close-Packed Cobalt Molybdenum Nitrides as Non-noble Metal Electrocatalysts for the Hydrogen Evolution Reaction

Cao, Bingfei; Veith, Gabriel M.; Neuefeind, Joerg C.; Adzic, Radoslav R.; Khalifah, Peter G.

Journal of the American Chemical Society (2013), 135 (51), 19186-19192CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

A two-step solid-state reaction for prepg. cobalt molybdenum nitride with a nanoscale morphol. was used to produce a highly active and stable electrocatalyst for the hydrogen evolution reaction (HER) under acidic conditions that achieves an iR-cor. c.d. of 10 mA cm-2 at -0.20 V vs RHE at low catalyst loadings of 0.24 mg/cm2 in rotating disk expts. under a H2 atmosphere. Neutron powder diffraction and pair distribution function (PDF) studies were used to overcome the insensitivity of x-ray diffraction data to different transition-metal nitride structural polytypes and show that this cobalt molybdenum nitride crystallizes in space group P63/mmc with lattice parameters of a = 2.85176(2) Å and c = 10.9862(3) Å and a formula of Co0.6Mo1.4N2. This space group results from the four-layered stacking sequence of a mixed close-packed structure with alternating layers of transition metals in octahedral and trigonal prismatic coordination and is a structure type for which HER activity has not previously been reported. Based on the accurate bond distances obtained from time-of-flight neutron diffraction data, the octahedral sites contain a mixt. of divalent Co and trivalent Mo, while the trigonal prismatic sites contain Mo in a higher oxidn. state. XPS studies confirm that at the sample surface nitrogen is present and N-H moieties are abundant.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslSqtLnO&md5=b65e53cfc94b1ff7a0d01e92312332b6
369
Chen, W.-F.; Iyer, S.; Iyer, S.; Sasaki, K.; Wang, C.-H.; Zhu, Y.; Muckerman, J. T.; Fujita, E. Biomass-Derived Electrocatalytic Composites for Hydrogen Evolution Energy Environ. Sci. 2013, 6, 1818– 1826 DOI: 10.1039/c3ee40596f

Google Scholar

369
Biomass-derived electrocatalytic composites for hydrogen evolution

Chen, Wei-Fu; Iyer, Shilpa; Iyer, Shweta; Sasaki, Kotaro; Wang, Chiu-Hui; Zhu, Yimei; Muckerman, James T.; Fujita, Etsuko

Energy & Environmental Science (2013), 6 (6), 1818-1826CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)

The prodn. of hydrogen from water electrolysis calls for an efficient non-precious-metal catalyst to make the process economically viable because of the high cost and the limited supply of the currently used platinum catalysts. Here we present such a catalyst made from earth-abundant molybdenum and common, humble soybeans (MoSoy). This catalyst, composed of a catalytic β-Mo2C phase and an acid-proof γ-Mo2N phase, drives the hydrogen evolution reaction (HER) with low overpotentials, and is highly durable in a corrosive acidic soln. over a period exceeding 500 h. When supported on graphene sheets, the MoSoy catalyst exhibits very fast charge transfer kinetics, and its performance rivals that of noble-metal catalysts such as Pt for hydrogen prodn. These findings prove that the soybean (as well as other high-protein biomass) is a useful material for the generation of catalysts incorporating an abundant transition metal, thereby challenging the exclusivity of platinum catalysts in the hydrogen economy.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXnvFyrs70%253D&md5=763844fc6718752f126e4d00875d3965
370
Xie, X.; Lin, L.; Liu, R.-Y.; Jiang, Y.-F.; Zhu, Q.; Xu, A.-W. The Synergistic Effect of Metallic Molybdenum Dioxide Nanoparticle Decorated Graphene as an Active Electrocatalyst for an Enhanced Hydrogen Evolution Reaction J. Mater. Chem. A 2015, 3, 8055– 8061 DOI: 10.1039/C5TA00622H

Google Scholar

370
The synergistic effect of metallic molybdenum dioxide nanoparticle decorated graphene as an active electrocatalyst for an enhanced hydrogen evolution reaction

Xie, Xiao; Lin, Ling; Liu, Rui-Yang; Jiang, Yi-Fan; Zhu, Qing; Xu, An-Wu

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (15), 8055-8061CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

As a durable and renewable fuel, H has attracted a huge amt. of global interest in its prodn. via different routes. Among these methods, the electrocatalytic H evolution reaction (HER) is one of the most promising ways for low-cost H prodn. in the future. A simple redox hydrothermal method was developed to fabricate a noble-metal-free MoO2/rGO composite for a highly efficient HER. GO nanosheets provide O-contg. functional groups for precursor attachment, and restrict growth of MoO2 nanoparticles (NPs) with a small size due to the space confinement effect among GO layers as well. Benefitting from a synergistic effect between metallic MoO2 NPs and graphene, the obtained MoO2/rGO composite exhibits excellent HER activity with a small onset overpotential of 190 mV, a large cathodic c.d., and a small Tafel slope of 49 mV per decade, while MoO2 NPs or rGO itself is not a very efficient HER catalyst. Addnl., the MoO2/rGO composite displays good stability after 1000 potential cycles under both acidic and alk. conditions. Dramatically improved HER activity and excellent stability are attributed to small size, more active sites, high cond. and a synergistic effect of MoO2 NPs and graphene. The development of the MoO2/rGO composite as an enhanced active HER catalyst broadens the members of Mo-based HER catalysts and provides an insight into the design and synthesis of other noble-metal-free materials for the cost-effective and environmentally friendly catalyst in electrochem. H prodn.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXks1aqt7k%253D&md5=94ee1d6c590571fb84bdfc19b94d5fe6
371
Chang, Y.-H.; Lin, C.-T.; Chen, T.-Y.; Hsu, C.-L.; Lee, Y.-H.; Zhang, W.; Wei, K.-H.; Li, L.-J. Highly Efficient Electrocatalytic Hydrogen Production by MoS_x Grown on Graphene-Protected 3D Ni Foams Adv. Mater. 2013, 25, 756– 760 DOI: 10.1002/adma.201202920

Google Scholar

371
Highly Efficient Electrocatalytic Hydrogen Production by MoSx Grown on Graphene-Protected 3D Ni Foams

Chang, Yung-Huang; Lin, Cheng-Te; Chen, Tzu-Yin; Hsu, Chang-Lung; Lee, Yi-Hsien; Zhang, Wenjing; Wei, Kung-Hwa; Li, Lain-Jong

Advanced Materials (Weinheim, Germany) (2013), 25 (5), 756-760CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

Hydrogen energy is clean and serves as one of the most promising candidates for replacing petroleum fuels in the future. Although the rare metals, such as platinum, have high efficiency in the hydrogen evolution reaction (HER), their scarcity and high cost inhibit large scale applications. To improve the electrocatalytic HER efficiency, it is crucial to effectively increase the surface area for catalyst loading. Hence, the research into three-dimensional (3D) electrode structures is emergent. A three-dimensional graphene foam synthesized on the Ni foam skeleton by chem. vapor deposition (CVD) has been reported. The graphene foam without the support of an Ni skeleton is brittle and is not able to serve as a 3D electrode for hosting catalysts. The 3D Ni foam is a low cost and conductive metal with a high surface area, which is ideal for use as a template to host catalysts for increasing the no. of reaction sites. However, it suffers from instability in acidic solns., and thus is not suitable for the electrocatalytic HER.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsFSntL%252FM&md5=1d3a218d9edc0aaec47ee611e22556bc
372
Levy, R. B.; Boudart, M. Platinum-Like Behavior of Tungsten Carbide in Surface Catalysis Science 1973, 181, 547– 549 DOI: 10.1126/science.181.4099.547

Google Scholar

372
Platinum-like behavior of tungsten carbide in surface catalysis

Levy, R. B.; Boudart, M.

Science (Washington, DC, United States) (1973), 181 (4099), 547-9CODEN: SCIEAS; ISSN:0036-8075.

WC catalyzes the formation of H2O from H and O at room temp., the redn. of WO3 by H in the presence of H2O, and the isomerization of Me4C to isopentane. This catalytic behavior, which is typical of Pt, is not exhibited at all by W. The surface electronic properties of the latter are therefore modified by C in such a way that they resemble those of Pt.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaE3sXkvVerurs%253D&md5=261e2de904e1c708715cbe8916279310
373
Pan, L. F.; Li, Y. H.; Yang, S.; Liu, P. F.; Yu, M. Q.; Yang, H. G. Molybdenum Carbide Stabilized on Graphene with High Electrocatalytic Activity for Hydrogen Evolution Reaction Chem. Commun. 2014, 50, 13135– 13137 DOI: 10.1039/C4CC05698A

Google Scholar

373
Molybdenum carbide stabilized on graphene with high electrocatalytic activity for hydrogen evolution reaction

Pan, Lin Feng; Li, Yu Hang; Yang, Shuang; Liu, Peng Fei; Yu, Ming Quan; Yang, Hua Gui

Chemical Communications (Cambridge, United Kingdom) (2014), 50 (86), 13135-13137CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)

The authors developed a general two-step method to prep. Mo carbide (Mo2C) nanoparticles stabilized by a C layer on reduced graphene oxide (RGO) sheets. The Mo2C-RGO hybrid showed excellent performance, which is attributed to the intimate interactions between Mo2C and graphene as well as the outer protection of the C layer.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVyhtr%252FF&md5=e2b598c990cf4f7812171b9fb96414dc
374
Zhang, X.; Meng, F.; Mao, S.; Ding, Q.; Shearer, M. J.; Faber, M. S.; Chen, J.; Hamers, R. J.; Jin, S. Amorphous MoS_xCl_y Electrocatalyst Supported by Vertical Graphene for Efficient Electrochemical and Photoelectrochemical Hydrogen Generation Energy Environ. Sci. 2015, 8, 862– 868 DOI: 10.1039/C4EE03240C

Google Scholar

374
Amorphous MoSxCly electrocatalyst supported by vertical graphene for efficient electrochemical and photoelectrochemical hydrogen generation

Zhang, Xingwang; Meng, Fei; Mao, Shun; Ding, Qi; Shearer, Melinda J.; Faber, Matthew S.; Chen, Junhong; Hamers, Robert J.; Jin, Song

Energy & Environmental Science (2015), 8 (3), 862-868CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)

We report amorphous MoSxCly as a high-performance electrocatalyst for both electrochem. and photoelectrochem. hydrogen generation. This novel ternary electrocatalyst is synthesized via chem. vapor deposition at temps. lower than those typically used to grow cryst. MoS2 nanostructures and structurally characterized. The MoSxCly electrocatalysts exhibit stable and high catalytic activity toward the hydrogen evolution reaction, as evidenced by large cathodic current densities at low overpotentials and low Tafel slopes (ca. 50 mV decade-1). The electrocatalytic performance can be further enhanced through depositing MoSxCly on conducting vertical graphenes. Furthermore, MoSxCly can be directly deposited on p-type silicon photocathodes to enable efficient photoelectrochem. hydrogen evolution.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXkslCquw%253D%253D&md5=3232dc40b1fdf8ad89b8df054f77e380
375
Zhou, W.; Zhou, J.; Zhou, Y.; Lu, J.; Zhou, K.; Yang, L.; Tang, Z.; Li, L.; Chen, S. N-Doped Carbon-Wrapped Cobalt Nanoparticles on N-Doped Graphene Nanosheets for High-Efficiency Hydrogen Production Chem. Mater. 2015, 27, 2026– 2032 DOI: 10.1021/acs.chemmater.5b00331

Google Scholar

375
N-Doped Carbon-Wrapped Cobalt Nanoparticles on N-Doped Graphene Nanosheets for High-Efficiency Hydrogen Production

Zhou, Weijia; Zhou, Jian; Zhou, Yucheng; Lu, Jia; Zhou, Kai; Yang, Linjing; Tang, Zhenghua; Li, Ligui; Chen, Shaowei

Chemistry of Materials (2015), 27 (6), 2026-2032CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)

Development of non-noble metal catalysts for H evolution reaction (HER) with both excellent activity and robust stability has remained a key challenge in the past decades. Herein, for the 1st time, N-doped C-wrapped Co nanoparticles supported on N-doped graphene nanosheets were prepd. by a facile solvothermal procedure and subsequent calcination at controlled temps. The electrocatalytic activity for HER was examd. in 0.5M H2SO4. Electrochem. measurements showed a small overpotential of only -49 mV with a Tafel slope of 79.3 mV/dec. Theor. calcns. based on d. functional theory showed that the catalytically active sites were due to C atoms promoted by the entrapped Co nanoparticles. The results may offer a new methodol. for the prepn. of effective catalysts for H2O splitting technol.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjvVOhtL0%253D&md5=55f338f1b102d48542cef352aacb8e78
376
Chowdhury, I.; Duch, M. C.; Mansukhani, N. D.; Hersam, M. C.; Bouchard, D. Colloidal Properties and Stability of Graphene Oxide Nanomaterials in the Aquatic Environment Environ. Sci. Technol. 2013, 47, 6288– 6296 DOI: 10.1021/es400483k

Google Scholar

376
Colloidal Properties and Stability of Graphene Oxide Nanomaterials in the Aquatic Environment

Chowdhury, Indranil; Duch, Matthew C.; Mansukhani, Nikhita D.; Hersam, Mark C.; Bouchard, Dermont

Environmental Science & Technology (2013), 47 (12), 6288-6296CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)

While graphene oxide (GO) has been found the most toxic graphene-based nanomaterial, its environmental fate is still unexplored. The aggregation kinetics and stability of GO were studied using time-resolved dynamic light scattering over a wide range of aquatic chemistries (pH, salt types (NaCl, MgCl2, CaCl2), ionic strength) relevant to natural and engineered systems. Although pH did not have a notable effect on GO stability from pH 4 to 10, salt type and ionic strength had significant effects on GO stability due to elec. double layer compression, similar to other colloidal particles. The crit. coagulation concn. (CCC) values of GO were detd. to be 44mM NaCl, 0.9mM CaCl2, and 1.3mM MgCl2. Aggregation and stability of GO in the aquatic environment followed colloidal theory (DLVO and Schulze-Hardy rule), even though GO's shape is not spherical. CCC values of GO were lower than reported fullerene CCC values and higher than reported C nanotube CCC values. CaCl2 destabilized GO more aggressively than MgCl2 and NaCl due to the binding capacity of Ca2+ with hydroxyl and carbonyl functional groups of GO. Natural org. matter significantly improved the stability of GO in water primarily due to steric repulsion. Long-term stability studies demonstrated that GO was highly stable in both natural and synthetic surface waters, although it settled quickly in synthetic groundwater. While GO remained stable in synthetic influent wastewater, effluent wastewater collected from a treatment plant rapidly destabilized GO, indicating GO will settle out during the wastewater treatment process and likely accumulate in biosolids and sludge. Overall, our findings indicate that GO nanomaterials will be stable in the natural aquatic environment and that significant aq. transport of GO is possible.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXnsFSiurs%253D&md5=74130013e227ff8e136217141f99f6fc
377
Achari, A.; Datta, K. K. R.; De, M.; Dravid, V. P.; Eswaramoorthy, M. Amphiphilic Aminoclay-RGO Hybrids: ASimple Strategy to Disperse a High Concentration of RGO in Water Nanoscale 2013, 5, 5316– 5320 DOI: 10.1039/c3nr01108a

Google Scholar

There is no corresponding record for this reference.
378
McCoy, T. M.; Brown, P.; Eastoe, J.; Tabor, R. F. Noncovalent Magnetic Control and Reversible Recovery of Graphene Oxide Using Iron Oxide and Magnetic Surfactants ACS Appl. Mater. Interfaces 2015, 7, 2124– 2133 DOI: 10.1021/am508565d

Google Scholar

378
Noncovalent Magnetic Control and Reversible Recovery of Graphene Oxide Using Iron Oxide and Magnetic Surfactants

McCoy, Thomas M.; Brown, Paul; Eastoe, Julian; Tabor, Rico F.

ACS Applied Materials & Interfaces (2015), 7 (3), 2124-2133CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

The unique charging properties of graphene oxide (GO) are exploited in the prepn. of a range of noncovalent magnetic GO materials, using microparticles, nanoparticles, and magnetic surfactants. Adsorption and desorption were controlled by modification of pH within a narrow window of <2 pH units. The benefit conferred by using charge-based adsorption is that the process is reversible, and the GO can be captured and sepd. from the magnetic nanomaterial, such that both components can be recycled. Iron oxide (Fe2O3) microparticles form a loosely flocculated gel network with GO, which is demonstrated to undergo magnetic compressional dewatering in the presence of an external magnetic field. For composites formed from GO and Fe2O3 nanoparticles, it is found that low Fe2O3:GO mass ratios ( < 5:1) favor flocculation of GO, whereas higher ratios ( > 5:1) cause overcharging of the surfaces resulting in restabilization. The effectiveness of the GO adsorption and magnetic capture process is demonstrated by sepg. traditionally difficult-to-recover gold nanoparticles (d ≈ 10 nm) from water. The fully recyclable nature of the assembly and capture process, combined with the vast adsorption capacity of GO, presents obvious and appealing advantages for applications in decontamination and water treatment.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhslCmtQ%253D%253D&md5=741eb062a94cc3ed2ee3bd5c9c32dbab
379
Le, N. H.; Seema, H.; Kemp, K. C.; Ahmed, N.; Tiwari, J. N.; Park, S.; Kim, K. S. Solution-Processable Conductive Micro-Hydrogels of Nanoparticle/Graphene Platelets Produced by Reversible Self-Assembly and Aqueous Exfoliation J. Mater. Chem. A 2013, 1, 12900– 12908 DOI: 10.1039/c3ta12735d

Google Scholar

379
Solution-processable conductive micro-hydrogels of nanoparticle/graphene platelets produced by reversible self-assembly and aqueous exfoliation

Le, Nhien H.; Seema, Humaira; Kemp, K. Christian; Ahmed, Nisar; Tiwari, Jitendra N.; Park, Sungjin; Kim, Kwang S.

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2013), 1 (41), 12900-12908CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Preventing the π-π restacking of graphene-based platelets is essential to advance their fundamental attributes in a wide range of scalable chem. processes. Using macroscopic hydrogels of H2O-intercalated metal-oxide/graphene platelets is a novel approach to produce microscopic hydrogels with extraordinary surface accessibility and electronic properties. Nanoparticle decoration and surface hydration prevent irreversible π-π stacking, paving the way for reversible self-assembly and aq.-phase exfoliation. The hydrophilic nanoparticle coating facilitates the colloidal stability of hybrid microgels in aq. and org. media without the assistance of surfactants. This allows these materials to versatilely function as basic building blocks as well as applied nanomaterials in wet-chem. applications. The preservation of unique properties of SnO2-decorated graphene platelets leads to significantly enhanced adsorptive and photocatalytic activities. By exploiting the fluorescence quenching effect, a dye-hydrogel complex can be used as a supramol. sensor for sensitive DNA detection. This study also initiates an innovative synthetic strategy to synthesize high-quality graphene-based nanomaterials.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFGgtL7P&md5=fd10db86672bd8f6ffb3ce0c4ce87763
380
Zubir, N. A.; Yacou, C.; Motuzas, J.; Zhang, X.; da Costa, J. C. D. Structural and Functional Investigation of Graphene Oxide-Fe₃O₄ Nanocomposites for the Heterogeneous Fenton-Like Reaction Sci. Rep. 2014, 4, 4594 DOI: 10.1038/srep04594

Google Scholar

380
Structural and functional investigation of graphene oxide-Fe3O4 nanocomposites for the heterogeneous Fenton-like reaction

Zubir, Nor Aida; Yacou, Christelle; Motuzas, Julius; Zhang, Xiwang; Diniz da Costa, Joao C.

Scientific Reports (2014), 4 (), article 4594CODEN: SRCEC3; ISSN:2045-2322. (Nature Publishing Group)

Graphene oxide-iron oxide (GO-Fe3O4) nanocomposites were synthesized by co-pptg. iron salts onto GO sheets in basic soln. The results showed that formation of two distinct structures was dependent upon the GO loading. The first structure corresponds to a low GO loading up to 10 wt%, assocd. with the beneficial intercalation of GO within (Fe3O4) nanoparticles and resulting in higher surface area up to 409 m[sup: null] g[sup: null]. High GO loading beyond 10 wt% led to the aggregation of Fe[sub: null]O[sub: null] nanoparticles and the undesirable stacking of GO sheets. The presence of strong interfacial interactions (Fe-O-C bonds) between both components at low GO loading lead to 20% higher degrdn. of Acid Orange 7 than the Fe3O4 nanoparticles in heterogeneous Fenton-like reaction. This behavior was attributed to synergistic structural and functional effect of the combined GO and Fe3O4 nanoparticles.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXptVyju7c%253D&md5=d3cb4a30101eb814cc39063fc4d09248
381
Liu, Y.; Jiang, X.; Li, B.; Zhang, X.; Liu, T.; Yan, X.; Ding, J.; Cai, Q.; Zhang, J. Halloysite Nanotubes@Reduced Graphene Oxide Composite for Removal of Dyes from Water and as Supercapacitors J. Mater. Chem. A 2014, 2, 4264– 4269 DOI: 10.1039/c3ta14594h

Google Scholar

381
Halloysite nanotubes@reduced graphene oxide composite for removal of dyes from water and as supercapacitors

Liu, Yushan; Jiang, Xiaoqing; Li, Baojun; Zhang, Xudong; Liu, Tiezhu; Yan, Xiaoshe; Ding, Jie; Cai, Qiang; Zhang, Jianmin

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (12), 4264-4269CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Halloysite nanotubes (HNTs) were dispersed and loaded homogeneously onto the surface of reduced graphene oxide (rGO) sheets via an electrostatic self-assembly process. The selective modification of the outmost surface with γ-aminopropyl triethoxysilane (APTES) was performed. The outmost surface of the APTES-HNTs (APHNTs) was converted into a pos. charged surface under acidic conditions due to the existence of amine-tailed short org. chains. A combination then occurred driven by the electrostatic force between the neg. GO sheets and pos. APHNTs. A HNTs@rGO composite (HGC) was fabricated after redn. of GO and investigated as an adsorbent and electrode material. The superior behavior of HGC for rhodamine B (RhB) removal and high performance as a supercapacitor highlight the potential applications of HGC in waste water treatment and energy storage issues.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjt12ru7w%253D&md5=b0a281727b1b69d2a4ce92abd143e757
382
Dong, Z.; Wang, D.; Liu, X.; Pei, X.; Chen, L.; Jin, J. Bio-Inspired Surface-Functionalization of Graphene Oxide for the Adsorption of Organic Dyes and Heavy Metal Ions with a Superhigh Capacity J. Mater. Chem. A 2014, 2, 5034– 5040 DOI: 10.1039/c3ta14751g

Google Scholar

382
Bio-inspired surface-functionalization of graphene oxide for the adsorption of organic dyes and heavy metal ions with a superhigh capacity

Dong, Zhihui; Wang, Dong; Liu, Xia; Pei, Xianfeng; Chen, Liwei; Jin, Jian

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (14), 5034-5040CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

By utilizing the synergistic effect of poly-dopamine (PD) with functional groups and graphene oxide (GO) with a high surface area, a series of sub-nano thick PD layer coated GO (PD/GO) composites were fabricated by a well-controlled self-polymn. of dopamine via catechol chem. and used for effectively decontaminating wastewater. The obtained PD/GO could selectively adsorb the dyes contg. an Eschenmoser structure and showed an extremely high adsorption capacity up to 2.1 g/g, which represents the highest value among dye adsorptions reported so far. The adsorption mechanism was investigated by FTIR anal., soln. pH effect, and some control expts. It was concluded that the adsorption process was based on the Eschenmoser salt assisted 1,4-Michael addn. reaction between the ortho position of the catechol phenolic hydroxyl group of PD and Eschenmoser groups in the dyes. The adsorption isotherms were explored according to the Langmuir and Freundlich models resp., and matched well with the Langmuir model. The thermodn. parameters (ΔH, ΔG, ΔS, and E) were also calcd., which suggested an exothermic and spontaneous adsorption process. In addn., PD/GO exhibited an improved adsorption capacity for removal of heavy metal ions (Pb2+ 53.6, Cu2+ 24.4, Cd2+ 33.3, and Hg2+ 15.2 mg/g, resp.) than pure PD and GO. Our results indicate the effectiveness of the synergistic effect of individual components on designing new functional composites with high performance.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXkt1yrsLc%253D&md5=0a6bd1147723422377afbd2cf3d3cb26
383
Mondal, T.; Bhowmick, A. K.; Krishnamoorti, R. Synthesis and Characterization of Bi-Functionalized Graphene and Expanded Graphite Using n-butyl Lithium and Their Use for Efficient Water Soluble Dye Adsorption J. Mater. Chem. A 2013, 1, 8144– 8153 DOI: 10.1039/c3ta11212h

Google Scholar

383
Synthesis and characterization of bi-functionalized graphene and expanded graphite using n-butyl lithium and their use for efficient water soluble dye adsorption

Mondal, Titash; Bhowmick, Anil K.; Krishnamoorti, Ramanan

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2013), 1 (28), 8144-8153CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Two effects of an organolithium reagent (n-Bu lithium) on graphene and expanded graphite are reported. Its ability to simultaneously scavenge protons and act as a nucleophile leads to a bi-functionalized graphitic system. Subsequent treatment with CO2 gas generates carboxylic functionality at the proton abstraction sites. This technique promises a greener method for single pot carboxylation for graphitic materials. The nucleophilicity of Bu lithium leads to efficient grafting of Bu groups. FTIR spectroscopy, XPS and thermogravimetric anal. are used to prove the success of the reaction. Raman spectroscopy reveals more defect sites for expanded graphite compared to graphene, which leads to a higher degree of functionalization. Atomic force microscopy shows that the functional groups generated are nano-spike-shaped pendant structures attached to the graphene. These functionalized materials are used as adsorbers for efficient and fast removal of water-sol. dyes by non-covalent interaction between the dye and the carboxylic groups of the graphitic system. Spectrometric as well as kinetic studies are reported for Crystal Violet Lactone dye adsorption. Both the modified materials show twice the adsorption capacity of the pristine materials. Superior dye adsorption properties were obsd. for the modified materials compared to graphene oxide.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtVWmtLvJ&md5=7c2d85a5bfc1adbe6d2b266927ffeb52
384
Liang, R.; Shen, L.; Jing, F.; Qin, N.; Wu, L. Preparation of MIL-53(Fe)-Reduced Graphene Oxide Nanocomposites by a Simple Self-Assembly Strategy for Increasing Interfacial Contact: Efficient Visible-Light Photocatalysts ACS Appl. Mater. Interfaces 2015, 7, 9507– 9515 DOI: 10.1021/acsami.5b00682

Google Scholar

384
Preparation of MIL-53(Fe)-Reduced Graphene Oxide Nanocomposites by a Simple Self-Assembly Strategy for Increasing Interfacial Contact: Efficient Visible-Light Photocatalysts

Liang, Ruowen; Shen, Lijuan; Jing, Fenfen; Qin, Na; Wu, Ling

ACS Applied Materials & Interfaces (2015), 7 (18), 9507-9515CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

In this work, MIL-53(Fe)-reduced graphene oxide (M53-RGO) nanocomposites have been successfully fabricated by a facile and efficient electrostatic self-assembly strategy for improving the interfacial contact between RGO and the MIL-53(Fe). Compared with D-M53-RGO (direct synthesis of MIL-53(Fe)-reduced graphene oxide nanocomposites via one-pot Solvo-thermal approach), M53-RGO nanocomposites exhibit improved photocatalytic activity compared with the D-M53-RGO under identical exptl. conditions. After 80 min of visible light illumination (λ ≥ 420 nm), the redn. ratio of Cr(VI) is rapidly increased to 100%, which is also higher than that of ref. sample (N-doped TiO2). More significantly, the M53-RGO nanocomposites are proven to perform as bifunctional photocatalysts with considerable activity in the mixed systems (Cr(VI)/dyes) under visible light, which made it a potential candidate for industrial wastewater treatment. Combining with photoelectrochem. analyses, it could be revealed that the introduction of RGO would minimize the recombination of photogenerated electron-hole pairs. Addnl., the effective interfacial contact between MIL-53(Fe) and RGO surface would further accelerate the transfer of photogenerated electrons, leading to the enhancement of photocatalytic activity of M53-RGO toward photocatalytic reactions. Finally, a possible photocatalytic reaction mechanism is also investigated in detail.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmvVygtLk%253D&md5=1853feefd30b837880b29e97a0a23e66
385
Qi, X.; Tan, C.; Wei, J.; Zhang, H. Synthesis of Graphene-Conjugated Polymer Nanocomposites for Electronic Device Applications Nanoscale 2013, 5, 1440– 1451 DOI: 10.1039/c2nr33145d

Google Scholar

385
Synthesis of graphene-conjugated polymer nanocomposites for electronic device applications

Qi, Xiaoying; Tan, Chaoliang; Wei, Jun; Zhang, Hua

Nanoscale (2013), 5 (4), 1440-1451CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

A review. Graphene-based polymer nanocomposites have attracted increasing interest because of their superior physicochem. properties over polymers. Semiconductor conjugated polymers (CPs) with excellent dispersibility and stability, and efficient electronic and optical properties have been recently integrated with graphene to form a new class of functional nanomaterials. In this minireview, we will summarize the recent advances in the development of graphene-CP nanocomposites for electronic device applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvFGlt7k%253D&md5=a27bde3371eb8d1873ce1d4d2c63eee9
386
Lu, H.; Yao, Y.; Huang, W. M.; Hui, D. Noncovalently Functionalized Carbon Fiber by Grafted Self-Assembled Graphene Oxide and the Synergistic Effect on Polymeric Shape Memory Nanocomposites Composites, Part B 2014, 67, 290– 295 DOI: 10.1016/j.compositesb.2014.07.022

Google Scholar

386
Noncovalently functionalized carbon fiber by grafted self-assembled graphene oxide and the synergistic effect on polymeric shape memory nanocomposites

Lu, Haibao; Yao, Yongtao; Huang, Wei Min; Hui, David

Composites, Part B: Engineering (2014), 67 (), 290-295CODEN: CPBEFF; ISSN:1359-8368. (Elsevier Ltd.)

This paper presents an effective approach to significantly improve the elec. properties and recovery performance of shape memory polymer (SMP) nanocomposites that are able for Joule heating triggered shape recovery. Reduced graphene oxide (GO) is self-assembled and grafted onto the carbon fibers to enhance the interfacial bonding with the SMP matrix via Van der Waals and covalent crosslink, resp. Exptl. results verify that the elec. properties of SMP nanocomposites are significantly improved via a synergistic effect of GO and carbon fiber. The morphol. and porous structure of GO on the carbon fiber are characterized by electron microscope and optical microscopes, resp. Furthermore, the behavior of electro-activated recovery and the resultant temp. distribution within SMP nanocomposite are monitored and characterized. We demonstrate that this simple way is able to produce electro-activated SMP nanocomposites which are applicable for Joule heating at a lower elec. voltage.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtlahtL7M&md5=1804f5c15771ff7f13221c9a85e629e5
387
Lu, H.; Liang, F.; Gou, J.; Leng, J.; Du, S. Synergistic Effect of Ag Nanoparticle-Decorated Graphene Oxide and Carbon Fiber on Electrical Actuation of Polymeric Shape Memory Nanocomposites Smart Mater. Struct. 2014, 23, 085034 DOI: 10.1088/0964-1726/23/8/085034

Google Scholar

387
Synergistic effect of Ag nanoparticledecorated graphene oxide and carbon fiber on electrical actuation of polymeric shape memory nanocomposites

Lu, Haibao; Liang, Fei; Gou, Jihua; Leng, Jinsong; Du, Shanyi

Smart Materials and Structures (2014), 23 (8), 085034CODEN: SMSTER; ISSN:1361-665X. (IOP Publishing Ltd.)

This study reports an effective approach of significantly improving elec. properties and recovery performance of shape memory polymer (SMP) nanocomposite, of which its shape recovery was triggered by elec. resistive Joule heating. Reduced graphene oxide (GOs) self-assembled and grafted onto carbon fiber, were used to enhance the interfacial bonding with the SMP matrix via van der Waals force and covalent bond, resp. A layer of Ag nanoparticles was synthesized from Ag+ soln. and chem. deposited onto GO assemblies. These Ag nanoparticles were expected to bridge the gap between GO and improve the elec. cond. The exptl. results reveal that the elec. cond. of the SMP nanocomposite was significantly improved via the synergistic effect between Ag nanoparticle-decorated GO and carbon fiber. Finally, the elec. induced shape memory effect of the SMP nanocomposite was achieved, and the temp. distribution in the SMP nanocomposites was recorded and monitored. An effective approach was demonstrated to produce the electroactivated SMP nanocomposites and the resistive Joule heating was viable at a low elec. voltage below 10 V.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslCnt7fM&md5=7222c93b783e19a5dfe5332ff6421b8c
388
Love, J. C.; Estroff, L. A.; Kriebel, J. K.; Nuzzo, R. G.; Whitesides, G. M. Self-Assembled Monolayers of Thiolates on Metals as a Form of Nanotechnology Chem. Rev. 2005, 105, 1103– 1169 DOI: 10.1021/cr0300789

Google Scholar

388
Self-Assembled Monolayers of Thiolates on Metals as a Form of Nanotechnology

Love, J. Christopher; Estroff, Lara A.; Kriebel, Jennah K.; Nuzzo, Ralph G.; Whitesides, George M.

Chemical Reviews (Washington, DC, United States) (2005), 105 (4), 1103-1169CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)

A review. This article presents the complete review on the formation, structure, property, and potential application of self-assembled monolayer of thiolate on metal surface.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXis1ahsrc%253D&md5=f734cb3bf2643ececb8acc01b3adafb6
389
Schedin, F.; Geim, A. K.; Morozov, S. V.; Hill, E. W.; Blake, P.; Katsnelson, M. I.; Novoselov, K. S. Detection of Individual Gas Molecules Adsorbed on Graphene Nat. Mater. 2007, 6, 652– 655 DOI: 10.1038/nmat1967

Google Scholar

389
Detection of individual gas molecules adsorbed on graphene

Schedin, F.; Geim, A. K.; Morozov, S. V.; Hill, E. W.; Blake, P.; Katsnelson, M. I.; Novoselov, K. S.

Nature Materials (2007), 6 (9), 652-655CODEN: NMAACR; ISSN:1476-1122. (Nature Publishing Group)

Authors show that micrometre-size sensors made from graphene are capable of detecting individual events when a gas mol. attaches to or detaches from graphene's surface. The adsorbed mols. change the local carrier concn. in graphene one by one electron, which leads to step-like changes in resistance. The achieved sensitivity is due to the fact that graphene is an exceptionally low-noise material electronically, which makes it a promising candidate not only for chem. detectors but also for other applications where local probes sensitive to external charge, magnetic field or mech. strain are required.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXpvFKjsrs%253D&md5=dedbfc7b95a13316bcbb8ebc5956c1d3
390
Wang, X.; Li, X.; Zhang, L.; Yoon, Y.; Weber, P. K.; Wang, H.; Guo, J.; Dai, H. N-Doping of Graphene Through Electrothermal Reactions with Ammonia Science 2009, 324, 768– 771 DOI: 10.1126/science.1170335

Google Scholar

390
N-doping of graphene through electrothermal reactions with ammonia

Wang, Xinran; Li, Xiaolin; Zhang, Li; Yoon, Youngki; Weber, Peter K.; Wang, Hailiang; Guo, Jing; Dai, Hongjie

Science (Washington, DC, United States) (2009), 324 (5928), 768-771CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)

Graphene is readily p-doped by adsorbates, but for device applications, it would be useful to access the n-doped material. Individual graphene nanoribbons were covalently functionalized by N species through high-power elec. Joule heating in NH3 gas, leading to n-type electronic doping consistent with theory. The formation of the C-N bond should occur mostly at the edges of graphene where chem. reactivity is high. XPS and nanometer-scale secondary ion mass spectroscopy confirm the C-N species in graphene thermally annealed in NH3. We fabricated an n-type graphene field-effect transistor that operates at room temp.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXlsVelu7Y%253D&md5=6a7e6044aa6012fb08f599dcee2ae2d4
391
Joo, P.; Kim, B. J.; Jeon, E. K.; Cho, J. H.; Kim, B.-S. Optical Switching of the Dirac Point in Graphene Multilayer Field-Effect Transistors Functionalized with Spiropyran Chem. Commun. 2012, 48, 10978– 10980 DOI: 10.1039/c2cc35933b

Google Scholar

391
Optical switching of the Dirac point in graphene multilayer field-effect transistors functionalized with spiropyran

Joo, Piljae; Kim, Beom Joon; Jeon, Eun Kyung; Cho, Jeong Ho; Kim, Byeong-Su

Chemical Communications (Cambridge, United Kingdom) (2012), 48 (89), 10978-10980CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)

A facile method for achieving optical switching of the Dirac point and conductance in reduced graphene oxide multilayer FETs that are non-covalently functionalized with a photo-responsive spiropyran deriv. is presented. The photoresponsive transition from spiropyran to merocyanine induces the reversible optical switching in graphene based FETs.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsFSrtLbF&md5=959ffe3bb6d0312b59ee9a2de7adbac1
392
Li, B.; Klekachev, A. V.; Cantoro, M.; Huyghebaert, C.; Stesmans, A.; Asselberghs, I.; De Gendt, S.; De Feyter, S. Toward Tunable Doping in Graphene FETs by Molecular Self-Assembled Monolayers Nanoscale 2013, 5, 9640– 9644 DOI: 10.1039/c3nr01255g

Google Scholar

392
Toward tunable doping in graphene FETs by molecular self-assembled monolayers

Li, Bing; Klekachev, Alexander V.; Cantoro, Mirco; Huyghebaert, Cedric; Stesmans, Andre; Asselberghs, Inge; De Gendt, Stefan; De Feyter, Steven

Nanoscale (2013), 5 (20), 9640-9644CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

In this paper, we report the formation of self-assembled monolayers (SAMs) of oleylamine (OA) on highly oriented pyrolytic graphite (HOPG) and graphene surfaces and demonstrate the potential of using such org. SAMs to tailor the electronic properties of graphene. Mol. resoln. Atomic Force Microscopy (AFM) and Scanning Tunneling Microscopy (STM) images reveal the detailed mol. ordering. The elec. measurements show that OA strongly interacts with graphene leading to n-doping effects in graphene devices. The doping levels are tunable by varying the OA deposition conditions. Importantly, neither hole nor electron mobilities are decreased by the OA modification. As a benefit from this noncovalent modification strategy, the pristine characteristics of the device are recoverable upon OA removal. From this study, one can envision the possibility to correlate the graphene-based device performance with the mol. structure and supramol. ordering of the org. dopant.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFalt7zO&md5=8957414b90fdba82427f195fa9a59910
393
Long, B.; Manning, M.; Burke, M.; Szafranek, B. N.; Visimberga, G.; Thompson, D.; Greer, J. C.; Povey, I. M.; MacHale, J.; Lejosne, G. Non-Covalent Functionalization of Graphene Using Self-Assembly of Alkane-Amines Adv. Funct. Mater. 2012, 22, 717– 725 DOI: 10.1002/adfm.201101956

Google Scholar

393
Non-Covalent Functionalization of Graphene Using Self-Assembly of Alkane-Amines

Long, Brenda; Manning, Mary; Burke, Micheal; Szafranek, Bartholomaeus N.; Visimberga, Giuseppe; Thompson, Damien; Greer, James C.; Povey, Ian M.; MacHale, John; Lejosne, Guaylord; Neumaier, Daniel; Quinn, Aidan J.

Advanced Functional Materials (2012), 22 (4), 717-725CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)

A simple, versatile method for noncovalent functionalization of graphene based on soln.-phase assembly of alkane-amine layers is presented. Second-order Moller-Plesset (MP2) perturbation theory on a cluster model (methylamine on pyrene) yields a binding energy of ≈220 meV for the amine-graphene interaction, which is strong enough to enable formation of a stable aminodecane layer at room temp. Atomistic mol. dynamics simulations on an assembly of 1-aminodecane mols. indicate that a self-assembled monolayer can form, with the alkane chains oriented perpendicular to the graphene basal plane. The calcd. monolayer height (≈1.7 nm) is in good agreement with at. force microscopy data acquired for graphene functionalized with 1-aminodecane, which yield a continuous layer with mean thickness ≈1.7 nm, albeit with some island defects. Raman data also confirm that self-assembly of alkane-amines is a noncovalent process, i.e., it does not perturb the sp2 hybridization of the graphene. Passivation and adsorbate n-doping of graphene field-effect devices using 1-aminodecane, as well as high-d. binding of plasmonic metal nanoparticles and seeded at. layer deposition of inorg. dielecs. using 1,10-diaminodecane are also reported.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhs1ert7fI&md5=964d2252186b0008a0aa148bd8cfde32
394
Wang, H.; Bi, S.-G.; Ye, Y.-S.; Xue, Y.; Xie, X.-L.; Mai, Y.-W. An Effective Non-Covalent Grafting Approach to Functionalize Individually Dispersed Reduced Graphene Oxide Sheets with High Grafting Density, Solubility and Electrical Conductivity Nanoscale 2015, 7, 3548– 3557 DOI: 10.1039/C4NR06710J

Google Scholar

394
An effective non-covalent grafting approach to functionalize individually dispersed reduced graphene oxide sheets with high grafting density, solubility and electrical conductivity

Wang, Hao; Bi, Shu-Guang; Ye, Yun-Sheng; Xue, Yang; Xie, Xiao-Lin; Mai, Yiu-Wing

Nanoscale (2015), 7 (8), 3548-3557CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

Polymer-functionalized reduced graphene oxide (polymer-FG), produced as individually dispersed graphene sheets, offers new possibilities for the prodn. of nanomaterials that are useful for a broad range of potential applications. Although non-covalent functionalization has produced graphene with good dispersibility and a relatively complete conjugated network, there are few reports related to the effective functionalization of reduced graphene oxide (RGO) using a simple, general method. Herein, we report a facile and effective approach for the prepn. of polymer-FG from a non-covalently functionalized pyrene-terminal polymer in benzoyl alc. (BnOH). This arom. alc. (BnOH) was used as the liq. medium for the dispersion of graphene oxide (GO) with a pyrene-terminal polymer, and as an effective reductant; this makes the synthesis procedure convenient and the prodn. of polymer-FG easily scalable because the conversion of GO to RGO and the non-covalent functionalization proceed simultaneously. The resulting polymer-FG sheets show organo-dispersibility, high elec. cond. and good processability, and have a similar grafting d. comparable to covalently made materials, thus making them promising candidates for applications such as electrochem. devices, nanomaterials and polymer nanocomposites. Hence, this work provides a general methodol. for prepg. individually dispersed graphene sheets with desirable properties.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmtlCgsg%253D%253D&md5=50f620fcac686ab36857190416c9abf0
395
Kozhemyakina, N. V.; Englert, J. M.; Yang, G.; Spiecker, E.; Schmidt, C. D.; Hauke, F.; Hirsch, A. Non-Covalent Chemistry of Graphene: Electronic Communication with Dendronized Perylene Bisimides Adv. Mater. 2010, 22, 5483– 5487 DOI: 10.1002/adma.201003206

Google Scholar

395
Non-Covalent Chemistry of Graphene: Electronic Communication with Dendronized Perylene Bisimides

Kozhemyakina, Nina V.; Englert, Jan M.; Yang, Guang; Spiecker, Erdmann; Schmidt, Cordula D.; Hauke, Frank; Hirsch, Andreas

Advanced Materials (Weinheim, Germany) (2010), 22 (48), 5483-5487CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

We have demonstrated the binding and electronic interactions of graphene with dendronized perylene bisimides in homogeneous soln. Previously, this had been obsd. only in the solid state. This result opens the door for the non-covalent functionalization of graphene in org. solvents.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhsFGlt7%252FM&md5=f1d91b6718897f7905592832861b8ea0
396
Parvez, K.; Li, R.; Puniredd, S. R.; Hernandez, Y.; Hinkel, F.; Wang, S.; Feng, X.; Muellen, K. Electrochemically Exfoliated Graphene as Solution-Processable, Highly Conductive Electrodes for Organic Electronics ACS Nano 2013, 7, 3598– 3606 DOI: 10.1021/nn400576v

Google Scholar

396
Electrochemically Exfoliated Graphene as Solution-Processable, Highly Conductive Electrodes for Organic Electronics

Parvez, Khaled; Li, Rongjin; Puniredd, Sreenivasa Reddy; Hernandez, Yenny; Hinkel, Felix; Wang, Suhao; Feng, Xinliang; Mullen, Klaus

ACS Nano (2013), 7 (4), 3598-3606CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Soln.-processable thin layer graphene is an intriguing nanomaterial with tremendous potential for electronic applications. Electrochem. exfoliation of graphite furnishes graphene sheets of high quality. The electrochem. exfoliated graphene (EG) contains a high yield (>80%) of 1- to three-layer graphene flakes with high C/O ratio of 12.3 and low sheet resistance (4.8 kΩ/<<rar for a single EG sheet). Due to the soln. processability of EG, a vacuum filtration method in assocn. with dry transfer is introduced to produce large-area and highly conductive graphene films on various substrates. Also, the patterned EG can serve as high-performance source/drain electrodes for org. field-effect transistors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXkslWgt7k%253D&md5=8de9ed84d44ffcd61690e2f330d71dae
397
Woszczyna, M.; Winter, A.; Grothe, M.; Willunat, A.; Wundrack, S.; Stosch, R.; Weimann, T.; Ahlers, F.; Turchanin, A. All-Carbon Vertical van der Waals Heterostructures: Non-destructive Functionalization of Graphene for Electronic Applications Adv. Mater. 2014, 26, 4831– 4837 DOI: 10.1002/adma.201400948

Google Scholar

397
All-Carbon Vertical van der Waals Heterostructures: Non-Destructive Functionalization of Graphene for Electronic Applications

Woszczyna, Miroslaw; Winter, Andreas; Grothe, Miriam; Willunat, Annika; Wundrack, Stefan; Stosch, Rainer; Weimann, Thomas; Ahlers, Franz; Turchanin, Andrey

Advanced Materials (Weinheim, Germany) (2014), 26 (28), 4831-4837CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

Here we present a route to functionalization via engineering of all-carbon vertical heterostructures by mech. stacking of amino-terminated carbon nanomembrane (NH2-CNM) and single-layer graphene (SLG) sheets. CNMs are a novel two-dimensional (2D) carbon-based electronic material with dielec. properties made via electron-/photon-induced crosslinking of polycyclic arom. self-assembled monolayers.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXosV2mtrY%253D&md5=a23573988430effbfaaef1abeace0345
398
Nottbohm, C. T.; Turchanin, A.; Beyer, A.; Stosch, R.; Goelzhaeuser, A. Mechanically Stacked 1-nm-Thick Carbon Nanosheets: Ultrathin Layered Materials with Tunable Optical, Chemical, and Electrical Properties Small 2011, 7, 874– 883 DOI: 10.1002/smll.201001993

Google Scholar

398
Mechanically stacked 1-nm-thick carbon nanosheets. Ultrathin layered materials with tunable optical, chemical, and electrical properties

Nottbohm, Christoph T.; Turchanin, Andrey; Beyer, Andre; Stosch, Rainer; Goelzhaeuser, Armin

Small (2011), 7 (7), 874-883CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)

C nanosheets are mech. stable, free-standing 2-dimensional materials with a thickness of ≈1 nm and well defined phys. and chem. properties. They are made by radiation-induced crosslinking of arom. self-assembled monolayers. Herein, a route is presented to the scalable fabrication of multilayer nanosheets with tunable elec., optical, and chem. properties on insulating substrates. Stacks of ≤5 nanosheets with sizes of ≈1 cm2 on oxidized Si are studied. Their optical characteristics are investigated by visual inspection, optical microscopy, UV-vis reflection spectroscopy, and model calcns. Their chem. compn. is studied by XPS. The multilayer samples are then annealed in an ultrahigh vacuum at various temps. ≤1100 K. A subsequent investigation by Raman, x-ray photoelectron, and UV-vis reflection spectroscopy, as well as by elec. 4-point probe measurements, demonstrates that the layered nanosheets transform into nanocryst. graphene. This structural and chem. transformation is accompanied by changes in the optical properties and elec. cond. and opens up a new path for the fabrication of ultrathin functional conductive coatings.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXktFKnurc%253D&md5=8c59238736b632a05bfc5170a0e765e8
399
Wang, Z. X.; Eigler, S.; Ishii, Y.; Hu, Y. C.; Papp, C.; Lytken, O.; Steinruck, H. P.; Halik, M. A Facile Approach to Synthesize an Oxo-Functionalized Graphene/Polymer Composite for Low-Voltage Operating Memory Devices J. Mater. Chem. C 2015, 3, 8595– 8604 DOI: 10.1039/C5TC01861G

Google Scholar

399
A facile approach to synthesize an oxo-functionalized graphene/polymer composite for low-voltage operating memory devices

Wang, Zhenxing; Eigler, Siegfried; Ishii, Yoshitaka; Hu, Yichen; Papp, Christian; Lytken, Ole; Steinrueck, Hans-Peter; Halik, Marcus

Journal of Materials Chemistry C: Materials for Optical and Electronic Devices (2015), 3 (33), 8595-8604CODEN: JMCCCX; ISSN:2050-7534. (Royal Society of Chemistry)

Memory devices are a key technol. of the authors' era and one of the const. challenges is the redn. of their power consumption. Herein, graphene oxide with very few defects, i.e., ∼1 nm thin oxo-functionalized graphene deriv., can be used in memory devices operating at 3 V. A memory device stores charges in the material of the active channel. Thereby, writing and erasing information can be performed at low voltage, facilitating low power consumption. To enable operation at low voltage, a novel synthetic approach is necessary. The selective noncovalent electrostatic functionalization of mainly organosulfate ions is possible with dodecylammonium. This functionalization allows the noncovalent coating of flakes with a polystyrene-deriv. as nm-thin dielec. medium. The resulting polymer-wrapped composite has a height of ∼5 nm. The thin coating of a few nm is mandatory to make the memory device work at low voltage. Also, a self-assembled monolayer of an imidazolium deriv. further enhances the function of the memory device. The prepd. composite materials were characterized by state-of-the-art anal. including solid state NMR spectroscopy and TGA coupled with gas chromatog., mass spectroscopy or IR spectroscopy. Ref. expts. prove the importance of the controlled synthesis to enable the function of the memory device.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtFyqtrvL&md5=b08aa4044d842c0e693c08345d747de0
400
Roth, A.; Ragoussi, M.-E.; Wibmer, L.; Katsukis, G.; de la Torre, G.; Torres, T.; Guldi, D. M. Electron-Accepting Phthalocyanine Pyrene Conjugates: Towards Liquid Phase Exfoliation of Graphite and Photoactive Nanohybrid Formation with Graphene Chem. Sci. 2014, 5, 3432– 3438 DOI: 10.1039/C4SC00709C

Google Scholar

400
Electron-accepting phthalocyanine-pyrene conjugates: towards liquid phase exfoliation of graphite and photoactive nanohybrid formation with graphene

Roth, Alexandra; Ragoussi, Maria-Eleni; Wibmer, Leonie; Katsukis, Georgios; de la Torre, Gema; Torres, Tomas; Guldi, Dirk M.

Chemical Science (2014), 5 (9), 3432-3438CODEN: CSHCCN; ISSN:2041-6520. (Royal Society of Chemistry)

Herein, we describe the synthesis of a zinc(II) alkylsulfonylphthalocyanine-pyrene conjugate, its assembly with highly exfoliated graphite, and the investigation of the photophys. properties of the resulting nanohybrid. The presence of the pyrene unit in the conjugate is decisive in terms of non-covalently immobilizing the electron accepting phthalocyanines onto the basal plane of highly exfoliated graphite. As a matter of fact, strong interactions dominate the electronic properties of the nanohybrid in both the ground and excited states. For example, femtosecond pump probe expts. assist in corroborating an ultrafast charge sepn., i.e., the generation of the one-electron reduced radical anion of the phthalocyanine and one-electron oxidized graphene after irradn. at 387 nm, followed by slow charge recombination.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtValsrnO&md5=12ad240dfaffb6eca3fe405c9ccc9c10
401
Wang, Z.; Hu, G.; Liu, J.; Liu, W.; Zhang, H.; Wang, B. Coordinated Assembly of a New 3D Mesoporous Fe₃O₄@Cu₂O-Graphene Oxide Framework as a Highly Efficient and Reusable Catalyst for the Synthesis of Quinoxalines Chem. Commun. 2015, 51, 5069– 5072 DOI: 10.1039/C5CC00250H

Google Scholar

There is no corresponding record for this reference.
402
Ren, R.; Li, S.; Li, J.; Ma, J.; Liu, H.; Ma, J. Enhanced Catalytic Activity of Au Nanoparticles Self-Assembled on Thiophenol Functionalized Graphene Catal. Sci. Technol. 2015, 5, 2149– 2156 DOI: 10.1039/C4CY01620C

Google Scholar

402
Enhanced catalytic activity of Au nanoparticles self-assembled on thiophenol functionalized graphene

Ren, Ren; Li, Shuwen; Li, Jing; Ma, Jianxin; Liu, Hengzhi; Ma, Jiantai

Catalysis Science & Technology (2015), 5 (4), 2149-2156CODEN: CSTAGD; ISSN:2044-4753. (Royal Society of Chemistry)

A new catalyst contg. 1-2 nm Au nanoparticles anchored to thiophenol covalently functionalized graphene sheets (Au/TP-GS) was fabricated using a facile, synthetic approach. The details of the morphologies, size and dispersion of the Au nanoparticles (NPs) and the chem. compn. of the novel catalyst were verified by systematic characterization techniques, including transmission electron microscopy (TEM), high-resoln. transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray diffraction (XRD) and XPS. The resulting Au/TP-GS exhibited excellent catalytic activity for both the redn. of 4-nitrophenol and the photodegrdn. of Rhodamine B due to the synergistic effects between the TP-GS and Au NPs and the high utilization of the metal. The practical, efficient and facile in situ redn. approach to synthesize the nanocatalyst provides a more environmentally benign synthesis route to effectively produce low cost Au-based catalysts.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnvVamtA%253D%253D&md5=7319564121dac7892fbfd1bbbffd4b7f
403
Pathak, P.; Gupta, S.; Grosulak, K.; Imahori, H.; Subramanian, V. Nature-Inspired Tree-Like TiO₂ Architecture: A 3D Platform for the Assembly of CdS and Reduced Graphene Oxide for Photoelectrochemical Processes J. Phys. Chem. C 2015, 119, 7543– 7553 DOI: 10.1021/jp512160h

Google Scholar

403
Nature-Inspired Tree-Like TiO2 Architecture: A 3D Platform for the Assembly of CdS and Reduced Graphene Oxide for Photoelectrochemical Processes

Pathak, Pawan; Gupta, Satyajit; Grosulak, Kehley; Imahori, Hiroshi; Subramanian, Vaidyanathan

Journal of Physical Chemistry C (2015), 119 (14), 7543-7553CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)

A nature-inspired tree-like 3-dimensional hierarchical TiO2/TiO2 architecture was prepd. as a facade to strategically assemble reduced graphene oxide/RGO (a facile charge transporter) and Cd sulfide/CdS (a visible light harvester) is presented for the 1st time. The core 3-dimensional TiO2 heterostructure was prepd. using a TiCl3 mediated surface treatment of TiO2 nanorods on F-doped Sn oxide (FTO) coated glass-slides. The performance of the 3-dimensional TiO2, which varies as a function of the treatment time, was 1st examd. to achieve optimal photoelectrochem. response. Subsequently, the architecture was tested for its (i) theor. H2O-splitting potential and (ii) ability to immobilize chalcogenide nonocrystals (CdS) with and without RGO. The best applied bias to photoconversion efficiency (% ABPE) is 0.36% (-0.15 V vs. Ag/AgCl) for the TiO2 architecture. A 140% increase with CdS deposition on the branched TiO2 indicated the structures' ability to effectively immobilize the chalcogenide. The effect of RGO on the photoelectrochem. response was explored and an optimum loading (1 mg mL-1) of RGO was noted to boost the photoresponse by an addnl. 150% compared to CdS-only photoanodes. Further, stability anal. performed over 3 h showed that the presence of RGO significantly delays CdS corrosion-driven deactivation. Finally, the fundamental insights on the impact of RGO in the 3-dimensional TiO2/RGO/CdS photoanode and its effect on the charge transportation mechanism were examd. using electrochem. impedance spectroscopy.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXislSnt7w%253D&md5=980d8fdd9fc7b9b7f2cc99856da1bdfd
404
Padhi, D. K.; Parida, K.; Singh, S. K. Facile Fabrication Of RGO/N-GZ Mixed Oxide Nanocomposite For Efficient Hydrogen Production Under Visible Light J. Phys. Chem. C 2015, 119, 6634– 6646 DOI: 10.1021/acs.jpcc.5b00311

Google Scholar

There is no corresponding record for this reference.
405
Ullah, K.; Ye, S.; Lei, Z.; Cho, K.-Y.; Oh, W.-C. Synergistic Effect of PtSe₂ and Graphene Sheets Supported by TiO₂ as Cocatalysts Synthesized via Microwave Techniques for Improved Photocatalytic Activity Catal. Sci. Technol. 2015, 5, 184– 198 DOI: 10.1039/C4CY00886C

Google Scholar

405
Synergistic effect of PtSe2 and graphene sheets supported by TiO2 as cocatalysts synthesized via microwave techniques for improved photocatalytic activity

Ullah, Kefayat; Ye, Shu; Lei, Zhu; Cho, Kwang-Yeon; Oh, Won-Chun

Catalysis Science & Technology (2015), 5 (1), 184-198CODEN: CSTAGD; ISSN:2044-4753. (Royal Society of Chemistry)

Here we report a new composite material consisting of TiO2 nanoparticles grown in the presence of a layered PtSe2/graphene hybrid as a high-performance photocatalytic material. The heterogeneous PtSe2-graphene/TiO2 nanocomposites were successfully synthesized through a facile and fast microwave-assisted method. The prepd. composites were characterized through x-ray diffraction (XRD), SEM (SEM) with energy dispersive x-ray (EDX) spectroscopy, transmission electron microscopy (TEM), Raman spectroscopic anal., XPS, and UV-vis absorbance spectra and UV-vis diffuse reflectance spectra (DRS) analyses were obtained. The catalytic behavior was investigated through the decompn. of Rhodamine B (Rh. B) as a std. dye and Texbrite MST-L as an industrial dye. This extraordinary photocatalytic activity arises from the pos. synergetic effect between the PtSe2 and graphene components in this heterogeneous photocatalyst. In this study the graphene behaves as an electron transfer agent, collector, contributor and a source of active adsorption sites. The optical properties were also obsd. to be affected by the different wt.% of graphene in the composites by observing their resp. band gaps from DRS spectra.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVGjur7L&md5=f69ecc2874d132b5b2e34339e8c1368e
406
Jiang, D.; Du, X.; Liu, Q.; Hao, N.; Qian, J.; Dai, L.; Mao, H.; Wang, K. Anchoring AgBr Nanoparticles on Nitrogen-Doped Graphene for Enhancement of Electrochemiluminescence and Radical Stability Chem. Commun. 2015, 51, 4451– 4454 DOI: 10.1039/C4CC09926E

Google Scholar

There is no corresponding record for this reference.
407
Joseph, K. L. V.; Lim, J.; Anthonysamy, A.; Kim, H.-I.; Choi, W.; Kim, J. K. Squaraine-Sensitized Composite of a Reduced Graphene Oxide/TiO₂Photocatalyst: pi-pi Stacking as a New Method of Dye Anchoring J. Mater. Chem. A 2015, 3, 232– 239 DOI: 10.1039/C4TA04313H

Google Scholar

407
Squaraine-sensitized composite of a reduced graphene oxide/TiO2 photocatalyst: π-π stacking as a new method of dye anchoring

Joseph, K. L. Vincent; Lim, Jonghun; Anthonysamy, A.; Kim, Hyoung-il; Choi, Wonyong; Kim, Jin Kon

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (1), 232-239CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

The authors synthesized a near IR (NIR)-absorbing squaraine dye (VJ-S) showing strong absorption and emission maxima at 684 and 704 nm, resp., with a high molar absorptivity (ε) of 1.277 × 105 M-1 cm-1 and a band gap of 1.77 eV. Its oxidn. and redn. potentials are 0.889 and -0.795 V, resp., with HOMO and LUMO levels of -5.21 and -3.53 eV, resp. The authors also prepd. the self-assembled core/shell nanocomposite r-NGOT, where TiO2 is the core and reduced nano-sized graphene oxide (r-NGO) is the shell. When VJ-S was anchored on r-NGOT, it showed π-π stacking with r-NGO, which is confirmed by Fourier-transformed IR spectroscopy, XPS, high-resoln. TEM and EELS. The optical absorption spectrum of the VJ-S/r-NGOT nanocomposite measured with diffuse reflectance UV/visible absorption spectroscopy covers the whole range of visible light wavelengths up to 800 nm. The photocatalytic activity of VJ-S/r-NGOT at visible light wavelengths (λ > 420 nm) is much higher than that of r-NGOT alone.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVemsLjL&md5=a66cb055f3a5a34ab2d15e364c154b25
408
Ma, H.; Tian, J.; Cui, L.; Liu, Y.; Bai, S.; Chen, H.; Shan, Z. Porous Activated Graphene Nanoplatelets Incorporated in TiO₂ Photoanodes for High-Efficiency Dye-Sensitized Solar Cells J. Mater. Chem. A 2015, 3, 8890– 8895 DOI: 10.1039/C5TA00527B

Google Scholar

408
Porous activated graphene nanoplatelets incorporated in TiO2 photoanodes for high-efficiency dye-sensitized solar cells

Ma, Huanmei; Tian, Jianhua; Cui, Lan; Liu, Yuanyuan; Bai, Shuming; Chen, Hang; Shan, Zhongqiang

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (16), 8890-8895CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Activated graphene nanoplatelets (a-GNPs) were first prepd. by a hydrothermal method with KOH as the activating agent. The effects of the prepn. conditions on the morphol. and structure of the a-GNPs were studied in detail. Morphol. observations and N2 adsorption-desorption isotherms indicate that the a-GNPs exhibit a uniform pore size distribution and have a larger sp. surface area (113.5 m2 g-1) compared to graphene nanoplatelets (GNPs). The incorporation of a-GNPs (0.02 wt%) into a TiO2 film photoanode in a dye-sensitized solar cell (DSSC) enhances the short circuit current and energy conversion of the cell by 35.8% and 26.8%, resp. The TiO2/a-GNP composite photoanodes were characterized by UV-vis spectroscopy and electrochem. impedance spectroscopy. The results reveal that the three-dimensional porous structure of a-GNPs serves as an efficient pathway for electrolyte ions and electrons, which accelerates the electron transfer and charge sepn., and suppresses the electron recombination and back transport reaction in DSSCs. However, excessive a-GNP incorporation leads to a decrease in the dye adsorption and thus a low energy conversion efficiency of DSSCs.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXkvFGjsrk%253D&md5=85293eecfdcf482b1bd0cb75d5e274c0
409
Xu, L.; Huang, W.-Q.; Wang, L.-L.; Tian, Z.-A.; Hu, W.; Ma, Y.; Wang, X.; Pan, A.; Huang, G.-F. Insights into Enhanced Visible-Light Photocatalytic Hydrogen Evolution of g-C₃N₄ and Highly Reduced Graphene Oxide Composite: The Role of Oxygen Chem. Mater. 2015, 27, 1612– 1621 DOI: 10.1021/cm504265w

Google Scholar

409
Insights into Enhanced Visible-Light Photocatalytic Hydrogen Evolution of g-C3N4 and Highly Reduced Graphene Oxide Composite: The Role of Oxygen

Xu, Liang; Huang, Wei-Qing; Wang, Ling-Ling; Tian, Ze-An; Hu, Wangyu; Ma, Yanming; Wang, Xin; Pan, Anlian; Huang, Gui-Fang

Chemistry of Materials (2015), 27 (5), 1612-1621CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)

The reduced graphene oxide (RGO)-based composites have attracted intensive attention in research due to its superior performance as photocatalysts, but still lacking is the theor. understanding on the interactions between constituents, as well as the connection between such interaction and the enhanced photoactivity. Herein, the interaction between the g-C3N4 and RGO sheets is systematically explored by using state-of-the-art hybrid d. functional theory. It is demonstrated that the O atom plays a crucial role in the RGO-based composites. Compared to the isolated g-C3N4 monolayer, the band gap of composites obviously decreases, and at higher O concn., the levels in the vicinity of Fermi level are much more dispersive, indicating the smaller effective mass of the carrier. These changes are nonlinear on the O concn. Interestingly, appropriate O concn. alters the direct-gap composite to indirect-gap one. Most importantly, at a higher O concn., a type-II, staggered band alignment can be obtained in the g-C3N4-RGO interface, and neg. charged O atoms in the RGO are active sites, leading to the high hydrogen-evolution activity. Furthermore, the calcd. absorption spectra which vary with the O concn. shed light on different exptl. results. The findings pave the way for developing RGO-based composites for photocatalytic applications.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitVerur4%253D&md5=987aae3bb083bdec4a5f7f37d0daeac8
410
Meng, F.; Cushing, S. K.; Li, J.; Hao, S.; Wu, N. Enhancement of Solar Hydrogen Generation by Synergistic Interaction of La₂Ti₂O₇ Photocatalyst with Plasmonic Gold Nanoparticles and Reduced Graphene Oxide Nanosheets ACS Catal. 2015, 5, 1949– 1955 DOI: 10.1021/cs5016194

Google Scholar

410
Enhancement of Solar Hydrogen Generation by Synergistic Interaction of La2Ti2O7 Photocatalyst with Plasmonic Gold Nanoparticles and Reduced Graphene Oxide Nanosheets

Meng, Fanke; Cushing, Scott K.; Li, Jiangtian; Hao, Shimeng; Wu, Nianqiang

ACS Catalysis (2015), 5 (3), 1949-1955CODEN: ACCACS; ISSN:2155-5435. (American Chemical Society)

This report shows that incorporating nitrogen-doped La2Ti2O7 (NLTO) photocatalyst with gold nanoparticles and reduced graphene oxide (rGO) nanosheets improves the photocatalytic hydrogen generation rate significantly. The underlying mechanism of the photocatalysis enhancement by the presence of both the Au nanoparticles and the rGO nanosheets is revealed. Nitrogen doping alone can extend the light absorption range of photocatalyst to 550 nm. In addn., nitrogen doping has enabled plasmon-induced resonance energy transfer (PIRET) from the plasmonic Au nanoparticle to NLTO, inducing charge sepn. in NLTO under solar radiation up to 600 nm. The Au nanoparticles not only serve as the photosensitizers but also lead to a shift in the flat band potential, suppressing the charge recombination and improving the charge extn. The rGO does not affect the charge sepn. process but significantly increases the lifetime of photogenerated charge carriers.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXis1Kgurs%253D&md5=e0fd6a26ea07e8c6801bbed93d35b705
411
Feifel, S. C.; Stieger, K. R.; Lokstein, H.; Lux, H.; Lisdat, F. High Photocurrent Generation by Photosystem I on Artificial Interfaces Composed of pi-System-Modified Graphene J. Mater. Chem. A 2015, 3, 12188– 12196 DOI: 10.1039/C5TA00656B

Google Scholar

411
High photocurrent generation by photosystem I on artificial interfaces composed of π-system-modified graphene

Feifel, S. C.; Stieger, K. R.; Lokstein, H.; Lux, H.; Lisdat, F.

Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (23), 12188-12196CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)

Photosystem I (PSI) is a key component of the oxygenic photosynthetic electron transport chain because of its light-induced charge sepn. and electron transfer (ET) capabilities. We report the fabrication of an efficient graphene-biohybrid light-harvesting electrode consisting of cyanobacterial trimeric PSI complexes immobilized onto π-system-modified graphene electrodes. Based on the strong interaction between conjugated arom. compds. and the graphene material via π-π-stacking, we have designed a simple but smart platform to fabricate light-driven photoelectrochem. devices. Due to the possibility of surface property adaptation and the excellent cond. of graphene, the modified biohybrid electrodes exhibit a well-defined photoelectrochem. response. In particular, the PSI-graphene electrode applying pyrene butyric acid NHS ester displays a very high photocurrent output of 23 μA cm-2 already at the open circuit potential which can be further increased by an overpotential and the use of an electron acceptor (Me viologen) under air satn. up to 135 μA cm-2. Comparing the graphene-PSI biohybrid systems based on different π-system-modifiers reveals that the pyrene derivs. result in higher current outputs compared to the anthracene derivs. and that the covalent fixation during immobilization appears more efficient compared to simple adsorption. Interestingly, the pyrene-based PSI electrodes also display a nearly unidirectional photocurrent generation, establishing the feasibility of conjoining these nanomaterials as potential constructs in next-generation photovoltaic devices.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXntVWksbk%253D&md5=6e72273eafb6370f50014ea1a13a5172
412
Moon, G.-H.; Kim, W.; Bokare, A. D.; Sung, N.-E.; Choi, W. Solar Production of H₂O₂ on Reduced Graphene Oxide-TiO₂ Hybrid Photocatalysts Consisting of Earth-Abundant Elements Only Energy Environ. Sci. 2014, 7, 4023– 4028 DOI: 10.1039/C4EE02757D

Google Scholar

412
Solar production of H2O2 on reduced graphene oxide-TiO2 hybrid photocatalysts consisting of earth-abundant elements only

Moon, Gun-hee; Kim, Wooyul; Bokare, Alok D.; Sung, Nark-eon; Choi, Wonyong

Energy & Environmental Science (2014), 7 (12), 4023-4028CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)

A superior cocatalytic behavior of reduced graphene oxide (rGO) was obsd. for the photocatalytic prodn. of H2O2 in the TiO2-based system. The adsorption of phosphate on TiO2 enhanced the prodn. of H2O2 up to a millimolar level. The in situ formation of cobalt phosphate on rGO/TiO2 enabled the photocatalytic prodn. of H2O2 even in the absence of org. electron donors.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslOisLjN&md5=8185af3bfbe59c0170734852f5a76b38
413
Lee, D. H.; Song, D.; Kang, Y. S.; Park, W. I. Three-Dimensional Monolayer Graphene and TiO₂ Hybrid Architectures for High-Efficiency Electrochemical Photovoltaic Cells J. Phys. Chem. C 2015, 119, 6880– 6885 DOI: 10.1021/acs.jpcc.5b00178

Google Scholar

413
Three-Dimensional Monolayer Graphene and TiO2 Hybrid Architectures for High-Efficiency Electrochemical Photovoltaic Cells

Lee, Dong Hyun; Song, Donghoon; Kang, Yong Soo; Park, Won Il

Journal of Physical Chemistry C (2015), 119 (12), 6880-6885CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)

Three-dimensional (3D), tubular-structured monolayer graphene networks were hybridized with TiO2 nanoparticular layer for futuristic and robust electrode applications. A continuous form of 3-dimensional graphene with good carrier mobility provides a direct pathway for electrons to the current collector for a photoanode in dye-sensitized solar cells. This characteristic feature, coupled with its energy level, ensures an enhanced charge collection efficiency. Particular attention was paid to the graphene surface functionalization and the effective loading of TiO2 nanoparticles to improve the light harvesting and minimize electron recombination for a photoanode. The optimal hybrid structure resulted in a 10% enhanced energy conversion efficiency, compared to the TiO2-based analog without graphene. The impedance spectra confirmed that the increase in photovoltaic performance was mainly driven by the efficient charge collection through the 3-dimensional, tubular-structured monolayer graphene. This new electrode prototype can serve as a good complement to conventional TiO2 nanostructures.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjvFygsL8%253D&md5=092abc48cd199ab3c7de3bed5417c745
414
Shah, S.; Yin, P. T.; Uehara, T. M.; Chueng, S. D.; Yang, L.; Lee, K. B. Guiding Stem Cell Differentiation into Oligodendrocytes Using Graphene-Nanofiber Hybrid Scaffolds Adv. Mater. 2014, 26, 3673– 3680 DOI: 10.1002/adma.201400523

Google Scholar

414
Guiding stem cell differentiation into oligodendrocytes using graphene-nanofiber hybrid scaffolds

Shah, Shreyas; Yin, Perry T.; Uehara, Thiers M.; Chueng, Sy-Tsong Dean; Yang, Letao; Lee, Ki-Bum

Advanced Materials (Weinheim, Germany) (2014), 26 (22), 3673-3680CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

Herein, we report the use of a graphene-based nanomaterial for the design of hybrid nanofibrous scaffolds to guide NSC differentiation into oligodendrocytes (Figure I). Graphene-based nanomaterials, such as graphene oxide (GO), have recently gained considerable interest for tissue engineering applications due to their favorable chem., elec. and mech. propνerties. Besides serving as a highly elastic and flexible structural reinforcement, substrates coated with GO have been demonstrated to promote the growth and differentiation of various stem cell lines, including induced PSCs, MSCs and NSCs. Based on these considerations, we demonstrate the use of GO as an effective coating material in combination with electrospun nanofibers for the selective differentiation of NSCs into oligodendrocytes. By varying the amt. of GO coating on the nanofibers, we obsd. a GO concn.-dependent change in the expression of key neural markers, wherein coating with a higher concn. of GO was seen to promote differentiation into mature oligodendrocytes. Further investigation into the role of GO-coating on the nanofibrous scaffolds showed the overexpression of a no. of key integrin-related intracellular signaling mols. that are known to promote oligodendrocyte differentiation in normal development.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXkslCqtLk%253D&md5=ea562dbd74ce5b054fed11daa6e54fe1
415
Kim, T. H.; Shah, S.; Yang, L.; Yin, P. T.; Hossain, M. K.; Conley, B.; Choi, J. W.; Lee, K. B. Controlling Differentiation of Adipose-Derived Stem Cells Using Combinatorial Graphene Hybrid-Pattern Arrays ACS Nano 2015, 9, 3780– 3790 DOI: 10.1021/nn5066028

Google Scholar

415
Controlling Differentiation of Adipose-Derived Stem Cells Using Combinatorial Graphene Hybrid-Pattern Arrays

Kim, Tae-Hyung; Shah, Shreyas; Yang, Letao; Yin, Perry T.; Hossain, Md. Khaled; Conley, Brian; Choi, Jeong-Woo; Lee, Ki-Bum

ACS Nano (2015), 9 (4), 3780-3790CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Control of stem cell fate by modulating biophys. cues (e.g., micropatterns, nanopatterns, elasticity and porosity of the substrates) has emerged as an attractive approach in stem cell-based research. Here, we report a method for fabricating combinatorial patterns of graphene oxide (GO) to effectively control the differentiation of human adipose-derived mesenchymal stem cells (hADMSCs). In particular, GO line patterns were highly effective for modulating the morphol. of hADMSCs, resulting in enhanced differentiation of hADMSCs into osteoblasts. Moreover, by generating GO grid patterns, we demonstrate the highly efficient conversion of mesodermal stem cells to ectodermal neuronal cells (conversion efficiency = 30%), due to the ability of the grid patterns to mimic interconnected/elongated neuronal networks. This work provides an early demonstration of developing combinatorial graphene hybrid-pattern arrays for the control of stem cell differentiation, which can potentially lead to more effective stem cell-based treatment of incurable diseases/disorders.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlvV2jsL8%253D&md5=225ca53d82f4f051a820334868a10a6a
416
Park, J.; Kim, B.; Han, J.; Oh, J.; Park, S.; Ryu, S.; Jung, S.; Shin, J.; Lee, B. S.; Hong, B. H. Graphene Oxide Flakes as a Cellular Adhesive: Prevention of Reactive Oxygen Species Mediated Death of Implanted Cells for Cardiac Repair ACS Nano 2015, 9, 4987– 4999 DOI: 10.1021/nn507149w

Google Scholar

416
Graphene Oxide Flakes as a Cellular Adhesive: Prevention of Reactive Oxygen Species Mediated Death of Implanted Cells for Cardiac Repair

Park, Jooyeon; Kim, Bokyoung; Han, Jin; Oh, Jaewon; Park, Subeom; Ryu, Seungmi; Jung, Subin; Shin, Jung-Youn; Lee, Beom Seob; Hong, Byung Hee; Choi, Donghoon; Kim, Byung-Soo

ACS Nano (2015), 9 (5), 4987-4999CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Mesenchymal stem cell (MSC) implantation has emerged as a potential therapy for myocardial infarction (MI). However, the poor survival of MSCs implanted to treat MI has significantly limited the therapeutic efficacy of this approach. This poor survival is primarily due to reactive oxygen species (ROS) generated in the ischemic myocardium after the restoration of blood flow. ROS primarily causes the death of implanted MSCs by inhibiting the adhesion of the MSCs to extracellular matrixes at the lesion site (i.e., anoikis). In this study, we proposed the use of graphene oxide (GO) flakes to protect the implanted MSCs from ROS-mediated death and thereby improve the therapeutic efficacy of the MSCs. GO can adsorb extracellular matrix (ECM) proteins. The survival of MSCs, which had adhered to ECM protein-adsorbed GO flakes and were subsequently exposed to ROS in vitro or implanted into the ischemia-damaged and reperfused myocardium, significantly exceeded that of unmodified MSCs. Furthermore, the MSC engraftment improved by the adhesion of MSCs to GO flakes prior to implantation enhanced the paracrine secretion from the MSCs following MSC implantation, which in turn promoted cardiac tissue repair and cardiac function restoration. This study demonstrates that GO can effectively improve the engraftment and therapeutic efficacy of MSCs used to repair the injury of ROS-abundant ischemia and reperfusion by protecting implanted cells from anoikis.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXntlCms70%253D&md5=fb3ef2493f46de33e8483c7deae935af
417
Kang, S.; Park, J. B.; Lee, T. J.; Ryu, S.; Bhang, S. H.; La, W. G.; Noh, M. K.; Hong, B. H.; Kim, B. S. Covalent Conjugation of Mechanically Stiff Graphene Oxide Flakes to Three-Dimensional Collagen Scaffolds for Osteogenic Differentiation of Human Mesenchymal Stem Cells Carbon 2015, 83, 162– 172 DOI: 10.1016/j.carbon.2014.11.029

Google Scholar

417
Covalent conjugation of mechanically stiff graphene oxide flakes to three-dimensional collagen scaffolds for osteogenic differentiation of human mesenchymal stem cells

Kang, Seokyung; Park, Jong Bo; Lee, Tae-Jin; Ryu, Seungmi; Bhang, Suk Ho; La, Wan-Geun; Noh, Myung-Kyung; Hong, Byung Hee; Kim, Byung-Soo

Carbon (2015), 83 (), 162-172CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)

Mesenchymal stem cells (MSCs) preferentially differentiate to osteogenic lineage when cultured on mech. stiff substrates. However, collagen sponges, clin. approved scaffolds for bone regeneration, provide soft microenvironment to MSCs. Here, the authors demonstrate that the covalent conjugation of mech. stiff graphene oxide (GO) flakes to 3-dimensional (3D) collagen scaffolds improves the mech. properties of the scaffolds and promotes the osteogenic differentiation of human MSCs (hMSCs) cultured on the scaffolds. The covalent conjugation of GO flakes to collagen scaffolds increased the scaffold stiffness by 3-fold and did not cause cytotoxicity. HMSCs cultured on the GO-collagen scaffolds demonstrated significantly enhanced osteogenic differentiation compared to cells cultured on non-modified collagen scaffolds. The enhanced osteogenic differentiation obsd. on the stiffer scaffolds was likely mediated by MSC mechanosensing because mols. that are involved in cell adhesion to stiff substrates were either up-regulated or activated. The 3D GO-collagen scaffolds could offer a powerful platform for stem cell research and orthopedic regenerative medicine.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvF2htb7E&md5=827b29634c947bdba18708fb70cf7070
418
Tiwari, J. N.; Vij, V.; Kemp, K. C.; Kim, K. S. Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules ACS Nano 2016, 10, 46– 80 DOI: 10.1021/acsnano.5b05690

Google Scholar

418
Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules

Tiwari, Jitendra N.; Vij, Varun; Kemp, K. Christian; Kim, Kwang S.

ACS Nano (2016), 10 (1), 46-80CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

A review. The study of electrochem. behavior of bioactive mols. has become one of the most rapidly developing scientific fields. Biotechnol. and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, the authors give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomols. including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here the authors draw an important distinction between enzymeless and enzyme-contg. carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhvVGiu7jI&md5=2a364e06b18b0f612fcd9bf343c26b4f
419
Gu, W.; Deng, X.; Gu, X.; Jia, X.; Lou, B.; Zhang, X.; Li, J.; Wang, E. Stabilized, Superparamagnetic Functionalized Graphene/Fe₃O₄@Au Nanocomposites for a Magnetically-Controlled Solid-State Electrochemiluminescence Biosensing Application Anal. Chem. 2015, 87, 1876– 1881 DOI: 10.1021/ac503966u

Google Scholar

419
Stabilized, Superparamagnetic Functionalized Graphene/Fe3O4@Au Nanocomposites for a Magnetically-Controlled Solid-State Electrochemiluminescence Biosensing Application

Gu, Wenling; Deng, Xi; Gu, Xiaoxiao; Jia, Xiaofang; Lou, Baohua; Zhang, Xiaowei; Li, Jing; Wang, Erkang

Analytical Chemistry (Washington, DC, United States) (2015), 87 (3), 1876-1881CODEN: ANCHAM; ISSN:0003-2700. (American Chemical Society)

Herein, a multifunctional nanoarchitecture has been developed by integrating the branched poly(ethylenimine) functionalized graphene/iron oxide hybrids (BGNs/Fe3O4) and luminol capped gold nanoparticles (luminol-AuNPs). The luminescent luminol-AuNPs as an electrochemiluminescence marker can be assembled on the nanocarrier of BGNs/Fe3O4 hybrids efficiently via the Au-N chem. bonds and electrostatic adsorption. Meanwhile, the multifunctional nanoarchitecture has been proved with excellent electron transfer, good stability, high emission intensity, etc. Furthermore, the authors successfully developed an ultrasensitive magnetically-controlled solid-state electrochemiluminescence (ECL) platform for label-free detn. of HeLa cells using this multifunctional nanocomposite. Excellent performance of the magnetically-controlled ECL biosensing platform has been achieved including a high sensitivity for HeLa cells with a linear range from 20 to 1 × 104 cells/mL, good stability, and reproducibility.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFGrsrrP&md5=7020efde7c1b2b0e22b0f63b18db99e9
420
Bagheri, H.; Arab, S. M.; Khoshsafar, H.; Afkhami, A. A Novel Sensor for Sensitive Determination of Atropine Based on a Co₃O₄-Reduced Graphene Oxide Modified Carbon Paste Electrode New J. Chem. 2015, 39, 3875– 3881 DOI: 10.1039/C5NJ00133A

Google Scholar

420
A novel sensor for sensitive determination of atropine based on a Co3O4-reduced graphene oxide modified carbon paste electrode

Bagheri, Hasan; Arab, Seyedeh Maryam; Khoshsafar, Hosein; Afkhami, Abbas

New Journal of Chemistry (2015), 39 (5), 3875-3881CODEN: NJCHE5; ISSN:1144-0546. (Royal Society of Chemistry)

This paper has presented a novel strategy to carry out direct and sensitive detn. of atropine in complex matrixes based on the Co3O4-graphene modified carbon paste electrode. This novel nanostructure was characterized by different spectroscopic and electrochem. techniques including SEM, X-ray diffraction, Fourier transform IR spectroscopy and electrochem. impedance spectroscopy. The fabricated electrochem. sensor showed good electrochem. response towards atropine. Under the optimized conditions, the calibration curve for atropine concn. was linear in the range from 0.1 to 3.2 μmol L-1 with the detection limit of 0.03 μmol L-1. In addn., the practical anal. performance of the sensor was examd. by evaluating the selective detection of atropine in biol. fluids and pharmaceutical samples with satisfied recovery. Therefore, the prepd. sensor may hold great promise for fast, simple and sensitive detection and biomedical anal. of atropine in various real samples.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjvF2lsLc%253D&md5=60c93c7d4718cac4eaad4f999f463b8b
421
Yoon, H. J.; Kim, T. H.; Zhang, Z.; Azizi, E.; Pham, T. M.; Paoletti, C.; Lin, J.; Ramnath, N.; Wicha, M. S.; Hayes, D. F. Sensitive Capture of Circulating Tumour Cells by Functionalized Graphene Oxide Nanosheets Nat. Nanotechnol. 2013, 8, 735– 741 DOI: 10.1038/nnano.2013.194

Google Scholar

421
Sensitive capture of circulating tumor cells by functionalized graphene oxide nanosheets

Yoon, Hyeun Joong; Kim, Tae Hyun; Zhang, Zhuo; Azizi, Ebrahim; Pham, Trinh M.; Paoletti, Costanza; Lin, Jules; Ramnath, Nithya; Wicha, Max S.; Hayes, Daniel F.; Simeone, Diane M.; Nagrath, Sunitha

Nature Nanotechnology (2013), 8 (10), 735-741CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)

The spread of cancer throughout the body is driven by circulating tumor cells (CTCs). These cells detach from the primary tumor and move from the bloodstream to a new site of subsequent tumor growth. They also carry information about the primary tumor and have the potential to be valuable biomarkers for disease diagnosis and progression, and for the mol. characterization of certain biol. properties of the tumor. However, the limited sensitivity and specificity of current methods for measuring and studying these cells in patient blood samples prevents the realization of their full clin. potential. The use of microfluidic devices is a promising method for isolating CTCs. However, the devices are reliant on three-dimensional structures, which limits further characterization and expansion of cells on the chip. Here we demonstrate an effective approach to isolating CTCs from blood samples of pancreatic, breast and lung cancer patients, by using functionalized graphene oxide nanosheets on a patterned gold surface. CTCs were captured with high sensitivity at a low concn. of target cells (73 ± 32.4% at 3-5 cells per mL blood).

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFaksbzL&md5=a6ac26c2fdf8b2e6c93bd63f6634a934
422
Lerner, M. B.; Matsunaga, F.; Han, G. H.; Hong, S. J.; Xi, J.; Crook, A.; Perez-Aguilar, J. M.; Park, Y. W.; Saven, J. G.; Liu, R. Scalable Production of Highly Sensitive Nanosensors Based on Graphene Functionalized with a Designed G Protein-Coupled Receptor Nano Lett. 2014, 14, 2709– 2714 DOI: 10.1021/nl5006349

Google Scholar

422
Scalable Production of Highly Sensitive Nanosensors Based on Graphene Functionalized with a Designed G Protein-Coupled Receptor

Lerner, Mitchell B.; Matsunaga, Felipe; Han, Gang Hee; Hong, Sung Ju; Xi, Jin; Crook, Alexander; Perez-Aguilar, Jose Manuel; Park, Yung Woo; Saven, Jeffery G.; Liu, Renyu; Johnson, A. T. Charlie

Nano Letters (2014), 14 (5), 2709-2714CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)

We have developed a novel, all-electronic biosensor for opioids that consists of an engineered μ-opioid receptor protein, with high binding affinity for opioids, chem. bonded to a graphene field-effect transistor to read out ligand binding. A variant of the receptor protein that provided chem. recognition was computationally redesigned to enhance its soly. and stability in an aq. environment. A shadow mask process was developed to fabricate arrays of hundreds of graphene transistors with av. mobility of ∼1500 cm2 V-1 s-1 and yield exceeding 98%. The biosensor exhibits high sensitivity and selectivity for the target naltrexone, an opioid receptor antagonist, with a detection limit of 10 pg/mL.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXmsVGksb0%253D&md5=aff37c7564398e2c3d1e476ce5840df0
423
Singh, M.; Holzinger, M.; Tabrizian, M.; Winters, S.; Berner, N. C.; Cosnier, S.; Duesberg, G. S. Noncovalently Functionalized Monolayer Graphene for Sensitivity Enhancement of Surface Plasmon Resonance Immunosensors J. Am. Chem. Soc. 2015, 137, 2800– 2803 DOI: 10.1021/ja511512m

Google Scholar

423
Noncovalently functionalized monolayer graphene for sensitivity enhancement of surface plasmon resonance immunosensors

Singh, Meenakshi; Holzinger, Michael; Tabrizian, Maryam; Winters, Sinead; Berner, Nina C.; Cosnier, Serge; Duesberg, Georg S.

Journal of the American Chemical Society (2015), 137 (8), 2800-2803CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

A highly efficient surface plasmon resonance (SPR) immunosensor is described using a functionalized single graphene layer on a thin gold film. The aim of this approach was two-fold: first, to amplify the SPR signal by growing graphene through chem. vapor deposition and, second, to control the immobilization of biotinylated cholera toxin antigen on copper coordinated nitrilotriacetic acid (NTA) using graphene as an ultrathin layer. The NTA groups were attached to graphene via pyrene derivs. implying π-π interactions. With this setup, an immunosensor for the specific antibody anticholera toxin with a detection limit of 4 pg mL-1 was obtained. In parallel, NTA polypyrrole films of different thicknesses were electrogenerated on the gold sensing platform where the optimal electropolymn. conditions were detd. For this optimized polypyrrole-NTA setup, the simple presence of a graphene layer between the gold and polymer film led to a significant increase of the SPR signal.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXislGjt7o%253D&md5=1e33859e918c99abd4882f6cc4cf06ac
424
Hu, W.; He, G.; Zhang, H.; Wu, X.; Li, J.; Zhao, Z.; Qiao, Y.; Lu, Z.; Liu, Y.; Li, C. M. Polydopamine-Functionalization of Graphene Oxide to Enable Dual Signal Amplification for Sensitive Surface Plasmon Resonance Imaging Detection of Biomarker Anal. Chem. 2014, 86, 4488– 4493 DOI: 10.1021/ac5003905

Google Scholar

424
Polydopamine-Functionalization of Graphene Oxide to Enable Dual Signal Amplification for Sensitive Surface Plasmon Resonance Imaging Detection of Biomarker

Hu, Weihua; He, Guangli; Zhang, Huanhuan; Wu, Xiaoshuai; Li, Jialin; Zhao, Zhiliang; Qiao, Yan; Lu, Zhisong; Liu, Yang; Li, Chang Ming

Analytical Chemistry (Washington, DC, United States) (2014), 86 (9), 4488-4493CODEN: ANCHAM; ISSN:0003-2700. (American Chemical Society)

Surface plasmon resonance imaging (SPRi) is one of the powerful tools for immunoassays with advantages of label-free, real-time, and high-throughput; however, it often suffers from limited sensitivity. Herein we report a dual signal amplification strategy utilizing polydopamine (PDA) functionalization of reduced graphene oxide (PDA-rGO) nanosheets for sensitive SPRi immunoassay in serum. The PDA-rGO nanosheet is synthesized by oxidative polymn. of dopamine in a gentle alk. soln. in the presence of graphene oxide (GO) sheets and then is antibody-conjugated via a spontaneous reaction between the protein and the PDA component. In the dual amplification mode, the first signal comes from capture of the antibody-conjugated PDA-rGO to form sandwiched immunocomplexes on the SPRi chip, followed by a PDA-induced spontaneous gold reductive deposition on PDA-rGO to further enhance the SPRi signal. The detection limit as low as 500 pg mL-1 is achieved on a nonfouling SPRi chip with high specificity and a wide dynamic range for a model biomarker, carcinoembryonic antigen (CEA) in 10% human serum.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXlsl2qur4%253D&md5=a0a38076d41b5264352de66f7aae3087
425
Yi, M.; Yang, S.; Peng, Z.; Liu, C.; Li, J.; Zhong, W.; Yang, R.; Tan, W. Two-Photon Graphene Oxide/Aptamer Nanosensing Conjugate for In Vitro or In Vivo Molecular Probing Anal. Chem. 2014, 86, 3548– 3554 DOI: 10.1021/ac5000015

Google Scholar

425
Two-Photon Graphene Oxide/Aptamer Nanosensing Conjugate for In Vitro or In Vivo Molecular Probing

Yi, Mei; Yang, Sheng; Peng, Zanying; Liu, Changhui; Li, Jishan; Zhong, Wenwan; Yang, Ronghua; Tan, Weihong

Analytical Chemistry (Washington, DC, United States) (2014), 86 (7), 3548-3554CODEN: ANCHAM; ISSN:0003-2700. (American Chemical Society)

Two-photon excitation (TPE) with near-IR (NIR) photons as the excitation source have the unique properties of lower tissue autofluorescence and self-absorption, reduced photodamage and photobleaching, higher spatial resoln., and deeper penetration depth (>500 μm). Carbon nanomaterials, for example, graphene oxide (GO), have the advantages of good biocompatibility, efficient transporters into cells, protecting the carried DNA or peptides from enzymic cleavage, and super fluorescence quenching efficiency. By combination of the nanostructured carbon materials with the TPE technique, herein the authors have designed an aptamer-two-photon dye (TPdye)/GO TPE fluorescent nanosensing conjugate for mol. probing in biol. fluids, living cells, and zebrafish. This approach takes advantage of the exceptional quenching capability of GO for the proximate TP dyes and the higher affinity of single-stranded DNA on GO than the aptamer-target complex. Successful in vitro and in vivo detection of ATP was demonstrated with this sensing strategy. The authors' results reveal that the GO/Aptamer-TPdye system not only is a robust, sensitive, and selective sensor for quant. detection of ATP in the complex biol. environment but also can be efficiently delivered into live cells or tissues and act as a "signal-on" in vivo sensor for specific, high-contrast imaging of target biomols. The authors' design provides a methodol. model scheme for development of future carbon nanomaterial-based two-photon fluorescent probes for in vitro or in vivo detn. of biol. or biol. relevant species.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjsFOltrc%253D&md5=db1133dc5148b04986eab7614b2dad31
426
Castrignano, S.; Gilardi, G.; Sadeghi, S. J. Human Flavin-Containing Monooxygenase 3 on Graphene Oxide for Drug Metabolism Screening Anal. Chem. 2015, 87, 2974– 2980 DOI: 10.1021/ac504535y

Google Scholar

There is no corresponding record for this reference.
427
Xu, S.; Man, B.; Jiang, S.; Wang, J.; Wei, J.; Xu, S.; Liu, H.; Gao, S.; Liu, H.; Li, Z. Graphene/Cu Nanoparticle Hybrids Fabricated by Chemical Vapor Deposition As Surface-Enhanced Raman Scattering Substrate for Label-Free Detection of Adenosine ACS Appl. Mater. Interfaces 2015, 7, 10977– 10987 DOI: 10.1021/acsami.5b02303

Google Scholar

427
Graphene/Cu Nanoparticle Hybrids Fabricated by Chemical Vapor Deposition As Surface-Enhanced Raman Scattering Substrate for Label-Free Detection of Adenosine

Xu, Shicai; Man, Baoyuan; Jiang, Shouzhen; Wang, Jihua; Wei, Jie; Xu, Shida; Liu, Hanping; Gao, Shoubao; Liu, Huilan; Li, Zhenhua; Li, Hongsheng; Qiu, Hengwei

ACS Applied Materials & Interfaces (2015), 7 (20), 10977-10987CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

We present a graphene/Cu nanoparticle hybrids (G/CuNPs) system as a surface-enhanced Raman scattering (SERS) substrate for adenosine detection. The Cu nanoparticles wrapped by a monolayer graphene shell were directly synthesized on flat quartz by chem. vapor deposition in a mixt. of methane and hydrogen. The G/CuNPs showed an excellent SERS enhancement activity for adenosine. The min. detected concn. of the adenosine in serum was demonstrated as low as 5 nM, and the calibration curve showed a good linear response from 5 to 500 nM. The capability of SERS detection of adenosine in real normal human urine samples based on G/CuNPs was also investigated and the characteristic peaks of adenosine were still recognizable. The reproducible and the ultrasensitive enhanced Raman signals could be due to the presence of an ultrathin graphene layer. The graphene shell was able to enrich and fix the adenosine mols., which could also efficiently maintain chem. and optical stability of G/CuNPs. Based on the G/CuNPs system, the ultrasensitive SERS detection of adenosine in varied matrixes was expected for the practical applications in medicine and biotechnol.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnvFCmsrk%253D&md5=31dcdf4707d8758e8f9c039c8371dd3f
428
Datta, K. K. R.; Kozak, O.; Ranc, V.; Havrdova, M.; Bourlinos, A. B.; Safarova, K.; Hola, K.; Tomankova, K.; Zoppellaro, G.; Otyepka, M. Quaternized Carbon Dot-Modified Graphene Oxide for Selective Cell Labelling – Controlled Nucleus and Cytoplasm Imaging Chem. Commun. 2014, 50, 10782– 10785 DOI: 10.1039/C4CC02637C

Google Scholar

428
Quaternized carbon dot-modified graphene oxide for selective cell labelling - controlled nucleus and cytoplasm imaging

Datta, K. K. R.; Kozak, O.; Ranc, V.; Havrdova, M.; Bourlinos, A. B.; Safarova, K.; Hola, K.; Tomankova, K.; Zoppellaro, G.; Otyepka, M.; Zboril, R.

Chemical Communications (Cambridge, United Kingdom) (2014), 50 (74), 10782-10785CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)

Cationic quaternized carbon dots (QCDs) and anionic graphene oxide sheets (GO) are combined via non-covalent interactions following a self-assembly pathway to form highly biocompatible and fluorescent hybrid materials. These hybrids act as selective probes with controlled labeling of the cell nucleus or cytoplasm depending on the QCD loading.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVOnurnE&md5=9d543eb037ba17e0810b2458e49f3695
429
Yin, P. T.; Shah, S.; Chhowalla, M.; Lee, K.-B. Design, Synthesis, and Characterization of Graphene-Nanoparticle Hybrid Materials for Bioapplications Chem. Rev. 2015, 115, 2483– 2531 DOI: 10.1021/cr500537t

Google Scholar

429
Design, Synthesis, and Characterization of Graphene-Nanoparticle Hybrid Materials for Bioapplications

Yin, Perry T.; Shah, Shreyas; Chhowalla, Manish; Lee, Ki-Bum

Chemical Reviews (Washington, DC, United States) (2015), 115 (7), 2483-2531CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)

A review.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjtVSjs7s%253D&md5=043909061e1bb64f0c5d595077cb25f5
430
Dikin, D. A.; Stankovich, S.; Zimney, E. J.; Piner, R. D.; Dommett, G. H. B.; Evmenenko, G.; Nguyen, S. T.; Ruoff, R. S. Preparation and Characterization of Graphene Oxide Paper Nature 2007, 448, 457– 460 DOI: 10.1038/nature06016

Google Scholar

430
Preparation and characterization of graphene oxide paper

Dikin, Dmitriy A.; Stankovich, Sasha; Zimney, Eric J.; Piner, Richard D.; Dommett, Geoffrey H. B.; Evmenenko, Guennadi; Nguyen, SonBinh T.; Ruoff, Rodney S.

Nature (London, United Kingdom) (2007), 448 (7152), 457-460CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)

The prepn. and characterization of graphite (graphene) oxide paper, a free-standing carbon-based membrane material made by flow-directed assembly of individual graphite oxide sheets, was reported. This new material outperforms many other paper-like materials in stiffness and strength. Its combination of macroscopic flexibility and stiffness is a result of a unique interlocking-tile arrangement of the nanoscale graphene oxide sheets.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXotFajurc%253D&md5=a777fe03851c7da3d3331b87e53e9e2f
431
Markovic, Z. M.; Harhaji-Trajkovic, L. M.; Todorovic-Markovic, B. M.; Kepic, D. P.; Arsikin, K. M.; Jovanovic, S. P.; Pantovic, A. C.; Dramicanin, M. D.; Trajkovic, V. S. In Vitro Comparison of the Photothermal Anticancer Activity of Graphene Nanoparticles and Carbon Nanotubes Biomaterials 2011, 32, 1121– 1129 DOI: 10.1016/j.biomaterials.2010.10.030

Google Scholar

431
In vitro comparison of the photothermal anticancer activity of graphene nanoparticles and carbon nanotubes

Markovic Zoran M; Harhaji-Trajkovic Ljubica M; Todorovic-Markovic Biljana M; Kepic Dejan P; Arsikin Katarina M; Jovanovic Svetlana P; Pantovic Aleksandar C; Dramicanin Miroslav D; Trajkovic Vladimir S

Biomaterials (2011), 32 (4), 1121-9 ISSN:.

The present study compared the photothermal anticancer activity of near-infrared (NIR)-excited graphene nanoparticles and carbon nanotubes (CNT). Despite lower NIR-absorbing capacity, suspension of polyvinylpyrrolidone-coated graphene sheets exposed to NIR radiation (808 nm, 2 W/cm(2)) generated more heat than DNA or sodium dodecylbenzenesulfonate-solubilized single-wall CNT under the same conditions. Accordingly, graphene nanoparticles performed significantly better than CNT in inducing photothermal death of U251 human glioma cells in vitro. The superior photothermal sensitivity of graphene sheets could be largely explained by their better dispersivity, which has been supported by a simple calculation taking into account thermodynamic, optical and geometrical properties of the two type of carbon nanoparticles. The mechanisms of graphene-mediated photothermal killing of cancer cells apparently involved oxidative stress and mitochondrial membrane depolarization resulting in mixed apoptotic and necrotic cell death characterized by caspase activation/DNA fragmentation and cell membrane damage, respectively.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3cbps1Khtg%253D%253D&md5=580788bb0a8c3d1789eb91988c3ddb0d
432
Bitounis, D.; Ali-Boucetta, H.; Hong, B. H.; Min, D.-H.; Kostarelos, K. Prospects and Challenges of Graphene in Biomedical Applications Adv. Mater. 2013, 25, 2258– 2268 DOI: 10.1002/adma.201203700

Google Scholar

432
Prospects and Challenges of Graphene in Biomedical Applications

Bitounis, Dimitrios; Ali-Boucetta, Hanene; Hong, Byung Hee; Min, Dal-Hee; Kostarelos, Kostas

Advanced Materials (Weinheim, Germany) (2013), 25 (16), 2258-2268CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

A review. Graphene materials have entered a phase of maturity in their development that is characterized by their explorative utilization in various types of applications and fields from electronics to biomedicine. Herein, we describe the recent advances made with graphene-related materials in the biomedical field and the challenges facing these exciting new tools both in terms of biol. activity and toxicol. profiling in vitro and in vivo. Graphene materials today have mainly been explored as components of biosensors and for construction of matrixes in tissue engineering. Their antimicrobial activity and their capacity to act as drug delivery platforms have also been reported, however, not as coherently. This report will attempt to offer some perspective as to which areas of biomedical applications can expect graphene-related materials to constitute a tool offering improved functionality and previously unavailable options.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXktFWmtL4%253D&md5=ba4c3e140c5b2d9ed9f2aec4fef327f2
433
Feng, L.; Wu, L.; Qu, X. New Horizons for Diagnostics and Therapeutic Applications of Graphene and Graphene Oxide Adv. Mater. 2013, 25, 168– 186 DOI: 10.1002/adma.201203229

Google Scholar

433
New Horizons for Diagnostics and Therapeutic Applications of Graphene and Graphene Oxide

Feng, Lingyan; Wu, Li; Qu, Xiaogang

Advanced Materials (Weinheim, Germany) (2013), 25 (2), 168-186CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)

A review. Graphene, a one-atom-thick two-dimensional (2D) layer of sp2-bonded carbon, has received worldwide attention owing to its extraordinary phys. and chem. properties. Recently, great efforts have been devoted to explore potential applications of graphene and its oxide in life science, esp. in disease-related diagnostics, near-IR (NIR) phototherapy and imaging. Here we will introduce recent advances and new horizons in this area, and focus on the rising progress on NIR photothermal therapy for cancer and Alzheimer's disease (AD), human telomerase detection, stem cell proliferation and differentiation on graphene substrate, diagnosis of cancer cell and related biomarkers, drug/nucleotide/peptide delivery and cell imaging, which have not been comprehensively reviewed. We hope to provide an outlook to the applications of graphene and its oxide, esp. on the new horizons in this field, and inspire broader interests across various disciplines.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhslSku7rI&md5=748900b5a2700207a8c74c9e4ada990f
434
Robinson, J. T.; Tabakman, S. M.; Liang, Y.; Wang, H.; Casalongue, H. S.; Daniel, V.; Dai, H. Ultrasmall Reduced Graphene Oxide with High Near-Infrared Absorbance for Photothermal Therapy J. Am. Chem. Soc. 2011, 133, 6825– 6831 DOI: 10.1021/ja2010175

Google Scholar

434
Ultrasmall Reduced Graphene Oxide with High Near-Infrared Absorbance for Photothermal Therapy

Robinson, Joshua T.; Tabakman, Scott M.; Liang, Yongye; Wang, Hailiang; Sanchez Casalongue, Hernan; Vinh, Daniel; Dai, Hongjie

Journal of the American Chemical Society (2011), 133 (17), 6825-6831CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

We developed nanosized, reduced graphene oxide (nano-rGO) sheets with high near-IR (NIR) light absorbance and biocompatibility for potential photothermal therapy. The single-layered nano-rGO sheets were ∼20 nm in av. lateral dimension, functionalized noncovalently by amphiphilic PEGylated polymer chains to render stability in biol. solns. and exhibited 6-fold higher NIR absorption than nonreduced, covalently PEGylated nano-GO. Attaching a targeting peptide bearing the Arg-Gly-Asp (RGD) motif to nano-rGO afforded selective cellular uptake in U87MG cancer cells and highly effective photoablation of cells in vitro. In the absence of any NIR irradn., nano-rGO exhibited little toxicity in vitro at concns. well above the doses needed for photothermal heating. This work established nano-rGO as a novel photothermal agent due to its small size, high photothermal efficiency, and low cost as compared to other NIR photothermal agents including gold nanomaterials and carbon nanotubes.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXksVeitb4%253D&md5=17a058f16c7b12f35d999923fcd7ff59
435
Jung, H. S.; Kong, W. H.; Sung, D. K.; Lee, M.-Y.; Beack, S. E.; Keum, D. H.; Kim, K. S.; Yun, S. H.; Hahn, S. K. Nanographene Oxide-Hyaluronic Acid Conjugate for Photothermal Ablation Therapy of Skin Cancer ACS Nano 2014, 8, 260– 268 DOI: 10.1021/nn405383a

Google Scholar

435
Nanographene Oxide-Hyaluronic Acid Conjugate for Photothermal Ablation Therapy of Skin Cancer

Jung, Ho Sang; Kong, Won Ho; Sung, Dong Kyung; Lee, Min-Young; Beack, Song Eun; Keum, Do Hee; Kim, Ki Su; Yun, Seok Hyun; Hahn, Sei Kwang

ACS Nano (2014), 8 (1), 260-268CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Melanoma skin cancer is one of the most dangerous skin cancers and the main cause of skin-cancer-related mortality. Hyaluronic acid (HA) has been used as an effective transdermal delivery carrier of chem. drugs and biopharmaceuticals. In this work, a nanographene oxide-HA conjugate (NGO-HA) was synthesized for photothermal ablation therapy of melanoma skin cancer using a near-IR (NIR) laser. Confocal microscopy and ex vivo bioimaging clearly visualized the remarkable transdermal delivery of NGO-HA to tumor tissues in the skin of mice, which might be ascribed to highly expressed HA receptors and relatively leaky structures around tumor tissues, enabling the enhanced permeation and retention of nanoparticles. The NIR irradn. resulted in complete ablation of tumor tissues with no recurrence of tumorigenesis. The antitumor effect was confirmed by ELISA for caspase-3 activity and histol. and immuno-histochem. analyses with TUNEL assay for tumor apoptosis. Taken together, we could confirm the feasibility of transdermal NGO-HA for photothermal ablation therapy of melanoma skin cancers.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVWqtQ%253D%253D&md5=9512decbc7cef1787fc5228aa637325d
436
Liu, J.; Jiang, X.; Xu, L.; Wang, X.; Hennink, W. E.; Zhuo, R. Novel Reduction-Responsive Cross-Linked Polyethylenimine Derivatives by Click Chemistry for Nonviral Gene Delivery Bioconjugate Chem. 2010, 21, 1827– 1835 DOI: 10.1021/bc100191r

Google Scholar

436
Novel Reduction-Responsive Cross-Linked Polyethylenimine Derivatives by Click Chemistry for Nonviral Gene Delivery

Liu, Jia; Jiang, Xulin; Xu, Li; Wang, Xianmiao; Hennink, Wim E.; Zhuo, Renxi

Bioconjugate Chemistry (2010), 21 (10), 1827-1835CODEN: BCCHES; ISSN:1043-1802. (American Chemical Society)

Novel reducible disulfide-contg. crosslinked polyethylenimines (PEI-SS-CLs) were synthesized via click chem. and evaluated as nonviral gene delivery vectors. First, about four azide pendant groups were introduced into a low-mol.-wt. (LMW) PEI (1.8 kDa) to get an azide-terminated PEI. Then, click reaction between a disulfide-contg. dialkyne crosslinker and the azide functionalized LMW PEI resulted in a high-mol.-wt. disulfide-contg. crosslinked PEI composed of LMW constitute via a reducible crosslinker. The synthesized polymers were characterized by 1H NMR, FTIR, and size-exclusion chromatog. (SEC). It was shown that the obtained disulfide-contg. crosslinked PEIs were able to condense plasmid DNA into pos. charged nanoparticles. The degrdn. of the disulfide crosslinked polymers PEI-SS-CLs induced by DTT was confirmed by a gel retardation assay and SEC anal. In vitro expts. revealed that the reducible PEI-SS-CLs were less cytotoxic and more effective in gene transfection (in both the presence and absence of serum) than the control nondegradable 25-kDa PEI. This study demonstrates that a reducibly degradable cationic polymer composed of LMW PEI crosslinked via a disulfide-contg. linker possesses both higher gene transfection efficiency and lower cytotoxicity than PEI (25 kDa). These polymers are therefore attractive candidates for further in vivo evaluations.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtFehurzE&md5=c920ada0d4aba1a2ab694624bc3d1d7c
437
Ma, N.; Li, Y.; Xu, H.; Wang, Z.; Zhang, X. Dual Redox Responsive Assemblies Formed from Diselenide Block Copolymers J. Am. Chem. Soc. 2010, 132, 442– 443 DOI: 10.1021/ja908124g

Google Scholar

437
Dual Redox Responsive Assemblies Formed from Diselenide Block Copolymers

Ma, Ning; Li, Ying; Xu, Huaping; Wang, Zhiqiang; Zhang, Xi

Journal of the American Chemical Society (2010), 132 (2), 442-443CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)

A block copolymer with diselenide bonds in the polymer backbone was reported. This block copolymer was capable of forming micellar aggregates that were responsive to redox stimuli. Compared with other redox responsive aggregates, this type of diselenide-contg. block copolymer aggregates could be responsive to both oxidants and reductants even in a soln. with a very low concn. under mild conditions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhsFOrtrnJ&md5=fd796a6ece09a94910768265ae07cf8e
438
Yang, X.; Zhao, N.; Xu, F.-J. Biocleavable Graphene Oxide Based-Nanohybrids Synthesized via ATRP for Gene/Drug Delivery Nanoscale 2014, 6, 6141– 6150 DOI: 10.1039/c4nr00907j

Google Scholar

438
Biocleavable graphene oxide based-nanohybrids synthesized via ATRP for gene/drug delivery

Yang, Xinchao; Zhao, Nana; Xu, Fu-Jian

Nanoscale (2014), 6 (11), 6141-6150CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)

Graphene oxide (GO) was proven to be promising in many biomedical fields due to its biocompatibility, unique conjugated structure, easily tunable surface functionalization and facile synthesis. In this work, a flexible 2-step method was first developed to introduce the atom transfer radical polymn. (ATRP) initiation sites contg. disulfide bonds onto GO surfaces. Surface-initiated ATRP of (2-dimethyl amino)ethyl methacrylate (DMAEMA) was then employed to tailor the GO surfaces in a well-controlled manner, producing a series of org.-inorg. hybrids (termed as SS-GPDs) for highly efficient gene delivery. Under reducible conditions, the PDMAEMA side chains can be readily cleavable from the GO backbones, benefiting the resultant gene delivery process. Moreover, due to the conjugated structure of the graphene basal plane, SS-GPD can attach and absorb arom., water insol. drugs, such as 10-hydroxycamptothecin (CPT), producing SS-GPD-CPT. The MTT assay and the simultaneous double-staining procedure revealed that SS-GPD-CPT possessed a high potency of killing cancer cells in vitro. With a high aq. soly. and coulombic interaction with cell membrane, SS-GPDs may have great potential in gene/drug delivery fields.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXotFCiurY%253D&md5=d51196882c66daecde3165318af315d6
439
Sherlock, S. P.; Tabakman, S. M.; Xie, L.; Dai, H. Photothermally Enhanced Drug Delivery by Ultrasmall Multifunctional FeCo/Graphitic Shell Nanocrystals ACS Nano 2011, 5, 1505– 1512 DOI: 10.1021/nn103415x

Google Scholar

439
Photothermally Enhanced Drug Delivery by Ultrasmall Multifunctional FeCo/Graphitic Shell Nanocrystals

Sherlock, Sarah P.; Tabakman, Scott M.; Xie, Liming; Dai, Hongjie

ACS Nano (2011), 5 (2), 1505-1512CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

FeCo/graphitic carbon shell (FeCo/GC) nanocrystals (∼4-5 nm in diam.) with ultrahigh magnetization are synthesized, functionalized, and developed into multifunctional biocompatible materials. We demonstrate the ability of this material to serve as an integrated system for combined drug delivery, near-IR (NIR) photothermal therapy, and magnetic resonance imaging (MRI) in vitro. We show highly efficient loading of doxorubicin (DOX) by π-stacking on the graphitic shell to afford FeCo/GC-DOX complexes and pH sensitive DOX release from the particles. We observe enhanced intracellular drug delivery by FeCo/GC-DOX under 20 min of NIR laser (808 nm) induced hyperthermia to 43 °C, resulting in a significant increase of FeCo/GC-DOX toxicity toward breast cancer cells. The synergistic cancer cell killing by FeCo/GC-DOX drug delivery under photothermal heating is due to a ∼two-fold enhancement of cancer cell uptake of FeCo/GC-DOX complex and the increased DOX toxicity under the 43 °C hyperthermic condition. The combination of synergistic NIR photothermally enhanced drug delivery and MRI with the FeCo/GC nanocrystals could lead to a powerful multimodal system for biomedical detection and therapy.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtlCktr0%253D&md5=ca973caede159ffd6c51b34de6c5ba51
440
Dembereldorj, U.; Kim, M.; Kim, S.; Ganbold, E.-O.; Lee, S. Y.; Joe, S.-W. A Spatiotemporal Anticancer Drug Release Platform of PEGylated Graphene Oxide Triggered by Glutathione InVitro and In Vivo J. Mater. Chem. 2012, 22, 23845– 23851 DOI: 10.1039/c2jm34853e

Google Scholar

There is no corresponding record for this reference.
441
Kiyomiya, K.; Matsuo, S.; Kurebe, M. Mechanism of Specific Nuclear Transport of Adriamycin: The Mode of Nuclear Translocation of Adriamycin-Proteasome Complex Cancer Res. 2001, 61, 2467– 2471
Google Scholar

441
Mechanism of specific nuclear transport of adriamycin: the mode of nuclear translocation of adriamycin-proteasome complex

Kiyomiya, Ken-Ichi; Matsuo, Saburou; Kurebe, Masaru

Cancer Research (2001), 61 (6), 2467-2471CODEN: CNREA8; ISSN:0008-5472. (American Association for Cancer Research)

Adriamycin (ADM), an anthracycline anticancer agent, is selectively stored in the nuclei of a variety of proliferating cells, but the precise mechanism of specific nuclear transport of ADM is not well known. Recently, the authors demonstrated that ADM shows high binding affinity to the cytoplasmic proteasomes of L1210 mouse leukemia cells and that taken up ADM by the cells selectively binds to proteasomes. Nuclear targeting of proteasome in proliferating cells may be mediated by the nuclear localization signals that are found in several of the α-type subunits of the 20S proteasome. To confirm nuclear transport of the ADM-proteasome complex, the authors synthesized a photoactive ADM analog, N-(p-azidobenzoyl)-ADM, and generated a photoaffinity-labeled proteasome complex. The 26S proteasome purified from the cytosol of L1210 cells had a high affinity to N-(p-azidobenzoyl)-ADM. SDS-PAGE anal. of the photoaffinity-labeled proteasome showed that low mol. wt. bands (∼21-31 kDa) of 20S proteasome had the highest photoaffinity. The photoaffinity-labeled proteasome was distributed in the cytoplasm and nuclei of digitonin-permeabilized L1210 and B-16 mouse melanoma cells in the presence of the cytosolic fraction and ATP. The rate of nuclear translocation of the proteasome was low in the absence of ATP. These results suggest that the proteasome is a specific translocator of ADM from the cytoplasm to the nucleus and that 20S proteasome components are the dominant ADM-binding sites. The nuclear transport of ADM-proteasome complex is regulated by an ATP-dependent nuclear pore-mediated mechanism.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXisVSlu7s%253D&md5=1be75211fa74f5bc633f4bc81ece2b43
442
Ochs, M.; Carregal-Romero, S.; Rejman, J.; Braeckmans, K.; De Smedt, S. C.; Parak, W. J. Light-Addressable Capsules as Caged Compound Matrix for Controlled Triggering of Cytosolic Reactions Angew. Chem., Int. Ed. 2013, 52, 695– 699 DOI: 10.1002/anie.201206696

Google Scholar

442
Light-Addressable Capsules as Caged Compound Matrix for Controlled Triggering of Cytosolic Reactions

Ochs, Markus; Carregal-Romero, Susana; Rejman, Joanna; Braeckmans, Kevin; De Smedt, Stefaan C.; Parak, Wolfgang J.

Angewandte Chemie, International Edition (2013), 52 (2), 695-699CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

Multifunctional capsules are well-suited for in vitro delivery of cargo inside cells; technol. has advanced to a point at which these capsules could be a helpful tool for controlled multifunctional in vitro delivery. A large no. of capsules can be taken up by cells in vitro without causing acute cytotoxicity, even for capsules with large sizes of around 5 μm. The loading of cells can be specifically directed by incorporating magnetic NPs in the wall of the capsules. This is possible since magnetic field gradients, which are created by positioning a magnet in a flow channel system, trap the capsules close to the magnet. Capsules with different cargo can be directed by magnetic field gradients to specific regions of a cell culture. Our approach allows light-controlled release of a much larger class of mols. and also subsequent release of different mols. Moreover, the technique to open the capsules is applied on individual capsules, thereby permitting sequential opening of different capsules within one cell. Local disruption of the capsule walls also leads to (transient) permeability of the membrane of the lysosomes in which the illuminated capsules are located. Here, we demonstrate that this approach can be employed to orchestrate intracellular reactions.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1Ogs77M&md5=00e794eb5e9863fe331da6c45238e110
443
Kim, H.; Lee, D.; Kim, J.; Kim, T.-I.; Kim, W. J. Photothermally Triggered Cytosolic Drug Delivery via Endosome Disruption Using a Functionalized Reduced Graphene Oxide ACS Nano 2013, 7, 6735– 6746 DOI: 10.1021/nn403096s

Google Scholar

443
Photothermally Triggered Cytosolic Drug Delivery via Endosome Disruption Using a Functionalized Reduced Graphene Oxide

Kim, Hyunwoo; Lee, Duhwan; Kim, Jinhwan; Kim, Tae-il; Kim, Won Jong

ACS Nano (2013), 7 (8), 6735-6746CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)

Graphene oxide has unique physiochem. properties, showing great potential in biomedical applications. In the present work, functionalized reduced graphene oxide (PEG-BPEI-rGO) has been developed as a nanotemplate for photothermally triggered cytosolic drug delivery by inducing endosomal disruption and subsequent drug release. PEG-BPEI-rGO has the ability to load a greater amt. of doxorubicin (DOX) than unreduced PEG-BPEI-GO via π-π and hydrophobic interactions, showing high water stability. Loaded DOX could be efficiently released by glutathione (GSH) and the photothermal effect of irradiated near IR (NIR) in test tubes as well as in cells. Importantly, PEG-BPEI-rGO/DOX complex was found to escape from endosomes after cellular uptake by photothermally induced endosomal disruption and the proton sponge effect, followed by GSH-induced DOX release into the cytosol. Finally, it was concluded that a greater cancer cell death efficacy was obsd. in PEG-BPEI-rGO/DOX complex-treated cells with NIR irradn. than those with no irradn. This study demonstrated the development of the potential of a PEG-BPEI-rGO nanocarrier by photothermally triggered cytosolic drug delivery via endosomal disruption.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtVGqsLjJ&md5=192f3a742f31a723c22a34e7fbe4ba5e
444
Yan, L.; Chang, Y.-N.; Yin, W.; Tian, G.; Zhou, G. L.; Liu, X.; Xing, G.; Zhao, L.; Gu, Z.; Zhao, Y. On-Demand Generation of Singlet Oxygen from a Smart Graphene Complex for the Photodynamic Treatment of Cancer Cells Biomater. Sci. 2014, 2, 1412– 1418 DOI: 10.1039/C4BM00143E

Google Scholar

444
On-demand generation of singlet oxygen from a smart graphene complex for the photodynamic treatment of cancer cells

Yan, Liang; Chang, Ya-Nan; Yin, Wenyan; Tian, Gan; Zhou, Liangjun; Liu, Xiaodong; Xing, Gengmei; Zhao, Lina; Gu, Zhanjun; Zhao, Yuliang

Biomaterials Science (2014), 2 (10), 1412-1418CODEN: BSICCH; ISSN:2047-4849. (Royal Society of Chemistry)

Graphene oxide (GO) has been proven to be a highly efficient long-range quencher for various fluorescence processes, which intrinsically work through a photophys. mechanism similar to that of singlet oxygen generation (SOG). Under our hypothesis that GO may be capable of quenching the SOG process, here we design and synthesize a novel nanocomplex consisting of GO, a photosensitizer and an aptamer. We demonstrate that GO is an ideal SOG controller, which can reversibly quench and recover SOG depending on the interaction intensity between GO and a photosensitizer. Addnl., it can simultaneously act as a carrier for the efficient loading and delivery of the photosensitizers to cancer cells. Thus, during the delivery process, SOG of the nanocomplex can be completely inhibited by the quenching capacity of the GO even though there is light present; however, when the nanocomplex enters into cancer cells where target mols. are present, SOG is triggered by a target binding event and singlet oxygen is reversibly released from the nanocomplex, ultimately inducing significant cell death in the presence of light. This proof-of-concept study provides a new chem. strategy for creating a highly selective photodynamic therapy with low toxicity, using hydrophilic GO-based systems.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtV2qurzF&md5=9df13d8c868ee8dac046d0842a5531af
445
Dong, H.; Dai, W.; Ju, H.; Lu, H.; Wang, S.; Xu, L.; Zhou, S.-F.; Zhang, Y.; Zhang, X. Multifunctional Poly(L-lactide)-Polyethylene Glycol-Grafted Graphene Quantum Dots for Intracellular MicroRNA Imaging and Combined Specific-Gene-Targeting Agents Delivery for Improved Therapeutics ACS Appl. Mater. Interfaces 2015, 7, 11015– 11023 DOI: 10.1021/acsami.5b02803

Google Scholar

445
Multifunctional Poly(L-lactide)-Polyethylene Glycol-Grafted Graphene Quantum Dots for Intracellular MicroRNA Imaging and Combined Specific-Gene-Targeting Agents Delivery for Improved Therapeutics

Dong, Haifeng; Dai, Wenhao; Ju, Huangxian; Lu, Huiting; Wang, Shiyan; Xu, Liping; Zhou, Shu-Feng; Zhang, Yue; Zhang, Xueji

ACS Applied Materials & Interfaces (2015), 7 (20), 11015-11023CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)

Photoluminescent (PL) graphene quantum dots (GQDs) with large surface area and superior mech. flexibility exhibit fascinating optical and electronic properties and possess great promising applications in biomedical engineering. Here, a multifunctional nanocomposite of poly(L-lactide) (PLA) and polyethylene glycol (PEG)-grafted GQDs (f-GQDs) was proposed for simultaneous intracellular microRNAs (miRNAs) imaging anal. and combined gene delivery for enhanced therapeutic efficiency. The functionalization of GQDs with PEG and PLA imparts the nanocomposite with super physiol. stability and stable photoluminescence over a broad pH range, which is vital for cell imaging. Cell expts. demonstrate the f-GQDs excellent biocompatibility, lower cytotoxicity, and protective properties. Using the HeLa cell as a model, we found the f-GQDs effectively delivered a miRNA probe for intracellular miRNA imaging anal. and regulation. Notably, the large surface of GQDs was capable of simultaneous adsorption of agents targeting miRNA-21 and survivin, resp. The combined conjugation of miRNA-21-targeting and survivin-targeting agents induced better inhibition of cancer cell growth and more apoptosis of cancer cells, compared with conjugation of agents targeting miRNA-21 or survivin alone. These findings highlight the promise of the highly versatile multifunctional nanocomposite in biomedical application of intracellular mols. anal. and clin. gene therapeutics.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnslGitLs%253D&md5=463d7abeeef5b70efa9d4d78c6139ecb
446
Bianco, A. Graphene: Safe or Toxic? The Two Faces of the Medal Angew. Chem., Int. Ed. 2013, 52, 4986– 4997 DOI: 10.1002/anie.201209099

Google Scholar

446
Graphene: Safe or Toxic? The Two Faces of the Medal

Bianco, Alberto

Angewandte Chemie, International Edition (2013), 52 (19), 4986-4997CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)

A review. Graphene is considered the future revolutionary material. For its development, it is of fundamental importance to evaluate the safety profile and the impact on health. Graphene is part of a bigger family which has been identified as the graphene family nanomaterials (GFNs). Clarifying the existence of multiple graphene forms allows better understanding the differences between the components and eventually correlating their biol. effects to the physicochem. characteristics of each structure. Some in vitro and in vivo studies clearly showed no particular risks, while others have indicated that GFNs might become health hazards. This Minireview critically discusses the recent studies on the toxicity of GFNs to provide some perspective on the possible risks to their future development in materials and biomedical sciences.

>> More from SciFinder ^®
https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXlsl2jtrk%253D&md5=4f293b4b7482a9468c792ae44746e9ee

Cited By

ARTICLE SECTIONS

Jump To

This article is cited by 1901 publications.

Neda Khedri, Ali Reza Mahjoub, Amir Hossein Cheshme Khavar, Rubén Rizo, Juan M. Feliu. Selectivity-Enhanced Electroreduction of CO2 to CO at Novel Ru-Linked-GO Nanohybrids: the Role of Nanoarchitecture. Inorganic Chemistry 2024, 63 (17) , 7571-7588. https://doi.org/10.1021/acs.inorgchem.3c03733
Carlos Martín-Fernández, M. Merced Montero-Campillo, Ibon Alkorta. Hydrogen Bonds Are Never of an “Anti-electrostatic” Nature: A Brief Tour of a Misleading Nomenclature. The Journal of Physical Chemistry Letters 2024, 15 (15) , 4105-4110. https://doi.org/10.1021/acs.jpclett.4c00779
Jianjiang He, Xiaodong Li, Ze Yang, Deyi Zhang, Tiantian Lu, Wenjing Liu, Qin Liu, Kun Wang, Changshui Huang. HsGDY 3D Framework-Encapsulated Cu2O Quantum Dots for High-Efficiency Energy Storage. ACS Applied Materials & Interfaces 2024, 16 (14) , 18008-18018. https://doi.org/10.1021/acsami.3c16588
Andrew T. Krasley, Eugene Li, Jesus M. Galeana, Chandima Bulumulla, Abraham G. Beyene, Gozde S. Demirer. Carbon Nanomaterial Fluorescent Probes and Their Biological Applications. Chemical Reviews 2024, 124 (6) , 3085-3185. https://doi.org/10.1021/acs.chemrev.3c00581
Yohei Ishida. Atomic-Scale Imaging of Clay Mineral Nanosheets and Their Supramolecular Complexes through Electron Microscopy: A Supramolecular Chemist’s Perspective. Langmuir 2024, 40 (12) , 6065-6076. https://doi.org/10.1021/acs.langmuir.3c03779
Recep Isci, Koray Bahadir Donmez, Nilgun Karatepe, Turan Ozturk. High-Performance Thienothiophene and Single Wall Carbon Nanotube-Based Supercapacitor as a Free-Standing and Flexible Hybrid Energy Storage Material. ACS Applied Energy Materials 2024, 7 (4) , 1488-1494. https://doi.org/10.1021/acsaem.3c02737
Nyssa S. S. Capman, V. R. Saran Kumar Chaganti, Laura E. Simms, Christopher J. Hogan, Jr., Steven J. Koester. Using Machine Learning to Overcome Interfering Oxygen Effects in a Graphene Volatile Organic Compound Sensor. ACS Applied Materials & Interfaces 2024, 16 (6) , 7554-7564. https://doi.org/10.1021/acsami.3c16157
Tom Kasputis, Yawen He, Qiaoqiao Ci, Juhong Chen. On-Site Fluorescent Detection of Sepsis-Inducing Bacteria using a Graphene-Oxide CRISPR-Cas12a (GO-CRISPR) System. Analytical Chemistry 2024, 96 (6) , 2676-2683. https://doi.org/10.1021/acs.analchem.3c05459
Yong Li, Jianyun Cao, Guoliang Chen, Lijun He, Xincheng Du, Jiyang Xie, Yaming Wang, Wanbiao Hu. Scalable Production of Highly Conductive 2D NbSe2 Monolayers with Superior Electromagnetic Interference Shielding Performance. ACS Applied Materials & Interfaces 2024, 16 (5) , 6250-6260. https://doi.org/10.1021/acsami.3c15817
Zheng Li, Zhen Xu, Chao Gao. Selective Proximate Antarafacial Distribution of Oxidized Functional Groups on Graphene Oxide. The Journal of Physical Chemistry C 2024, 128 (3) , 1323-1331. https://doi.org/10.1021/acs.jpcc.3c06315
K.A. Shiral Fernando, Rajendr Thakuri, Amanda L. Barry Schroeder, Oscar N. Ruiz. Chemical Method for Recovery and Regeneration of Graphene Oxide. ACS Applied Bio Materials 2024, 7 (1) , 315-324. https://doi.org/10.1021/acsabm.3c00911
Syrine Affès, Akrivi-Maria Stamatelou, Xavier Fontrodona, Ahlem Kabadou, Clara Viñas, Francesc Teixidor, Isabel Romero. Enhancing Photoredox Catalysis in Aqueous Environments: Ruthenium Aqua Complex Derivatization of Graphene Oxide and Graphite Rods for Efficient Visible-Light-Driven Hybrid Catalysts. ACS Applied Materials & Interfaces 2024, 16 (1) , 507-519. https://doi.org/10.1021/acsami.3c13156
Priya Mandal, Sajal K. Ghosh. Graphene-Based Nanomaterials and Their Interactions with Lipid Membranes. Langmuir 2023, 39 (51) , 18713-18729. https://doi.org/10.1021/acs.langmuir.3c02805
Bei Ran, Lei Ran, Zuokai Wang, Jinfeng Liao, Dandan Li, Keda Chen, Wenlin Cai, Jungang Hou, Xiaojun Peng. Photocatalytic Antimicrobials: Principles, Design Strategies, and Applications. Chemical Reviews 2023, 123 (22) , 12371-12430. https://doi.org/10.1021/acs.chemrev.3c00326
Shi-Jie Yuan, Jing-Jing Wang, Bin Dong, Xiao-Hu Dai. Biomass-Derived Carbonaceous Materials with Graphene/Graphene-Like Structures: Definition, Classification, and Environmental Applications. Environmental Science & Technology 2023, 57 (45) , 17169-17177. https://doi.org/10.1021/acs.est.3c04203
Wenyuan Hu, Hongbo Li, Guoqing Zhong, Dingming Yang, Qiying Jiang, Huan Zhang, Qiulin Deng. Sensitive Detection of Trace Vitamin C via Enzyme-like Catalysis of S Defect-Rich Ultrathin 2D MoS2: Comprehensive Innovative Experiments on Two-Dimensional Materials for Undergraduates. Journal of Chemical Education 2023, 100 (10) , 4025-4030. https://doi.org/10.1021/acs.jchemed.3c00465
Osama R. M. Metawea, Miyuki Nara, Takeharu Murakami, Hirotaka Okabe, Naoki Matsuda, Satoshi Wada, Katsushi Fujii, Yoshihiro Ito, Masuki Kawamoto. Aqueous Suspensions of Carbon Nanomaterials with Platinum Nanoparticles for Solution-Processed Hydrogen-Producing Electrocatalysts. ACS Applied Nano Materials 2023, 6 (17) , 15521-15529. https://doi.org/10.1021/acsanm.3c02190
Cheng Xu, Xiang Yu, Yang Liu, Xiongzhi Zhang, Simin Liu. Versatile Graphene Oxide Hybrid Supramolecular Hydrogel Driven by Host–Guest Interaction Showing Excellent Mechanical and Sensing Properties and Photothermal Responsiveness. ACS Applied Polymer Materials 2023, 5 (9) , 7375-7389. https://doi.org/10.1021/acsapm.3c01281
Duwage C. Perera, Jayendran C. Rasaiah. Computational Study of H2O Adsorption, Hydrolysis, and Water Splitting on (ZnO)3 Nanoclusters Deposited on Graphene and Graphene Oxides. ACS Omega 2023, 8 (35) , 32185-32203. https://doi.org/10.1021/acsomega.3c04882
Guojun Zhang, Yipin Lv, Xinru Wei, Yuan Yuan, Fangfang Wang, Jin Yong Lee, Baotao Kang. Band-Gap Behaviors of Graphyne-/Graphdiyne-Derived Chiral Nanotubes. The Journal of Physical Chemistry C 2023, 127 (30) , 14982-14990. https://doi.org/10.1021/acs.jpcc.3c03182
Neeraj Sohal, Sonali Singla, Shweta J. Malode, Soumen Basu, Banibrata Maity, Nagaraj P. Shetti. Bioresource-Based Graphene Quantum Dots and Their Applications: A Review. ACS Applied Nano Materials 2023, 6 (13) , 10925-10943. https://doi.org/10.1021/acsanm.3c02185
Dayong Li, Yuling Shao, Haibo Ke, Shengquan Chang, Yong Kou, Lei Xiao, Gazi Hao. Synthesis of Covalently Modified Energetic Graphene Oxide/CuO Composites with Enhanced Catalytic Performance for Thermal Decomposition of Ammonium Perchlorate. ACS Omega 2023, 8 (25) , 22876-22886. https://doi.org/10.1021/acsomega.3c01865
Priyadarshi Roy Chowdhury Himani Medhi Krishna G. Bhattacharyya Chaudhery Mustansar Hussain . Future of Carbon Materials in Environmental Analysis. , 195-231. https://doi.org/10.1021/bk-2023-1441.ch009
Yujie Zhu, Quguang Li, Chunjie Wang, Yu Hao, Nailin Yang, Minjiang Chen, Jiansong Ji, Liangzhu Feng, Zhuang Liu. Rational Design of Biomaterials to Potentiate Cancer Thermal Therapy. Chemical Reviews 2023, 123 (11) , 7326-7378. https://doi.org/10.1021/acs.chemrev.2c00822
Shubhalaxmi Choudhury, Samarjit Pattnayak, Ugrabadi Sahoo, Pragnyashree Aparajita, Garudadhwaj Hota. S-Doped rGO-Enwrapped Magnetically Porous NiFe2O4/CuS Heterojunction: An Efficient Z-Scheme Nano-Photocatalyst for Visible-Light-Driven Tetracycline Degradation and 4-Nitrophenol Reduction. Industrial & Engineering Chemistry Research 2023, 62 (21) , 8191-8209. https://doi.org/10.1021/acs.iecr.3c00213
Jianqi Ye, Jinhua Lu, Tuotuo Ma, Dan Wen. Untangling the Effects of Doping Carbon with Diverse Heteroatoms on the Bioelectrochemistry of Glucose Oxidase. Analytical Chemistry 2023, 95 (19) , 7685-7692. https://doi.org/10.1021/acs.analchem.3c00758
Alok Tripathi, José Bonilla-Cruz. Review on Healthcare Biosensing Nanomaterials. ACS Applied Nano Materials 2023, 6 (7) , 5042-5074. https://doi.org/10.1021/acsanm.3c00941
Lopamudra Bishwal, Subhajit Kar, Santanu Bhattacharyya. Role of Noncovalent Interactions in N,P-Functionalized Luminescent Carbon Dots for Ultrasensitive Detection of Moisture in D2O: Boosting Visible-NIR Light Sensitivity. ACS Applied Materials & Interfaces 2023, 15 (12) , 15907-15916. https://doi.org/10.1021/acsami.3c01620
Natalia Alzate-Carvajal, Jaewoo Park, Ilhem Bargaoui, Ranjana Rautela, Zachary J. Comeau, Lukas Scarfe, Jean-Michel Ménard, Seth B. Darling, Benoît H. Lessard, Adina Luican-Mayer. Arrays of Functionalized Graphene Chemiresistors for Selective Sensing of Volatile Organic Compounds. ACS Applied Electronic Materials 2023, 5 (3) , 1514-1520. https://doi.org/10.1021/acsaelm.2c01544
Lei Zhao, Giulio Rosati, Andrew Piper, Cecilia de Carvalho Castro e Silva, Liming Hu, Qiuyue Yang, Flavio Della Pelle, Ruslán R. Alvarez-Diduk, Arben Merkoçi. Laser Reduced Graphene Oxide Electrode for Pathogenic Escherichia coli Detection. ACS Applied Materials & Interfaces 2023, 15 (7) , 9024-9033. https://doi.org/10.1021/acsami.2c20859
Ziyi Meng, Yuxi Zou, Ningning Li, Bei Wang, Xudong Fu, Rong Zhang, Shengfei Hu, Xujin Bao, Xiao Li, Feng Zhao, Qingting Liu. Graphene Oxide-Intercalated Microbial Montmorillonite to Moderate the Dependence of Nafion-Based PEMFCs in High-Humidity Environments. ACS Applied Energy Materials 2023, 6 (3) , 1771-1780. https://doi.org/10.1021/acsaem.2c03666
Amir Khajavinia, Anas El-Aneed. Carbon-Based Nanoparticles and Their Surface-Modified Counterparts as MALDI Matrices. Analytical Chemistry 2023, 95 (1) , 100-114. https://doi.org/10.1021/acs.analchem.2c04537
Liangzhikun Xiao, Zhongai Hu, Yuanyuan He, Long Jiao, Liwen Lv, Qing Yin, Qiaoqiao Wei, Zhimin Li, Yuying Yang. Aqueous Electrolyte Asymmetric Supercapacitors Based on the 5-Hydroxyindole Molecule Electrode and MXene with Efficient Energy Storage. ACS Applied Energy Materials 2023, 6 (1) , 68-78. https://doi.org/10.1021/acsaem.2c02098
Kolleboyina Jayaramulu, Soumya Mukherjee, Dulce M. Morales, Deepak P. Dubal, Ashok Kumar Nanjundan, Andreas Schneemann, Justus Masa, Stepan Kment, Wolfgang Schuhmann, Michal Otyepka, Radek Zbořil, Roland A. Fischer. Graphene-Based Metal–Organic Framework Hybrids for Applications in Catalysis, Environmental, and Energy Technologies. Chemical Reviews 2022, 122 (24) , 17241-17338. https://doi.org/10.1021/acs.chemrev.2c00270
Juan Casanova-Chafer, Rocio Garcia-Aboal, Pedro Atienzar, Marta Feliz, Eduard Llobet. Octahedral Molybdenum Iodide Clusters Supported on Graphene for Resistive and Optical Gas Sensing. ACS Applied Materials & Interfaces 2022, 14 (51) , 57122-57132. https://doi.org/10.1021/acsami.2c15716
Yucong Wang, Huabo Huang, Jian Luo, Liang Li, Juan Huang, Peng Yu, Chuanxi Xiong. Achieving Enhanced Interfacial Interaction and High Dielectric Properties in PVDF Composite Film Containing Polyaniline-Derived N-Doped Carbon. ACS Applied Electronic Materials 2022, 4 (12) , 5825-5837. https://doi.org/10.1021/acsaelm.2c01011
Nyssa S. S. Capman, Xue V. Zhen, Justin T. Nelson, V. R. Saran Kumar Chaganti, Raia C. Finc, Michael J. Lyden, Thomas L. Williams, Mike Freking, Gregory J. Sherwood, Philippe Bühlmann, Christopher J. Hogan, Steven J. Koester. Machine Learning-Based Rapid Detection of Volatile Organic Compounds in a Graphene Electronic Nose. ACS Nano 2022, 16 (11) , 19567-19583. https://doi.org/10.1021/acsnano.2c10240
. Nanostructured Materials for Sustainable Energy: Design, Evaluation, and Applications. https://doi.org/10.1021/bk-2022-1421
Jeanne N’Diaye Raunaq Bagchi Jingbo Liu Keryn Lian . Organic-Carbon Composites for Next Generation Capacitive Electrodes. , 83-115. https://doi.org/10.1021/bk-2022-1421.ch003
Pooja Ratre, Bulbul Jain, Roshani Kumari, Suresh Thareja, Rajnarayan Tiwari, Rupesh Kumar Srivastava, Irina Yu Goryacheva, Pradyumna Kumar Mishra. Bioanalytical Applications of Graphene Quantum Dots for Circulating Cell-Free Nucleic Acids: A Review. ACS Omega 2022, 7 (44) , 39586-39602. https://doi.org/10.1021/acsomega.2c05414
Krushnamurty Killi, Yuval Madmon, Ronen Verker, Roie Yerushalmi. Combined Atomic and Molecular Layer Deposition Surface Modification of Carbon Nanotubes for CNT–Epoxy Polymer Composites. ACS Applied Nano Materials 2022, 5 (10) , 15429-15440. https://doi.org/10.1021/acsanm.2c03471
Long Zhao, Farid Ahmed, Yating Zeng, Weiqing Xu, Hai Xiong. Recent Developments in G-Quadruplex Binding Ligands and Specific Beacons on Smart Fluorescent Sensor for Targeting Metal Ions and Biological Analytes. ACS Sensors 2022, 7 (10) , 2833-2856. https://doi.org/10.1021/acssensors.2c00992
Apostolos Koutsioukis, Georgios Florakis, Elias Sakellis, Vasilios Georgakilas. Stable Dispersion of Graphene in Water, Promoted by High-Yield, Scalable Exfoliation of Graphite in Natural Aqueous Extracts: The Role of Hydrophobic Organic Molecules. ACS Sustainable Chemistry & Engineering 2022, 10 (38) , 12552-12558. https://doi.org/10.1021/acssuschemeng.2c02326
Yitayal Admassu Workie, Cheng-Yu Kuo, Juwita Herlina Riskawati, Nattinee Krathumkhet, Toyoko Imae, Masaki Ujihara, Marie Pierre Krafft. Hierarchical Composite Nanoarchitectonics with a Graphitic Core, Dendrimer and Fluorocarbon Domains, and a Poly(ethylene glycol) Shell as O2 Reservoirs for Reactive Oxygen Species Production. ACS Applied Materials & Interfaces 2022, 14 (30) , 35027-35039. https://doi.org/10.1021/acsami.2c09812
Lulin Hu, Yi Yang, Jingcheng Hao, Lu Xu. Dual-Driven Mechanically and Tribologically Adaptive Hydrogels Solely Constituted of Graphene Oxide and Water. Nano Letters 2022, 22 (14) , 6004-6009. https://doi.org/10.1021/acs.nanolett.2c01489
Chaochao Gao, Wen Yu, Minghao Du, Bingxuan Zhu, Wanbao Wu, Yihong Liang, Dong Wu, Baoyu Wang, Mi Wang, Jiaheng Zhang. Facile Synthesis of Ag/Carbon Quantum Dots/Graphene Composites for Highly Conductive Water-Based Inks. ACS Applied Materials & Interfaces 2022, 14 (29) , 33694-33702. https://doi.org/10.1021/acsami.2c06298
Qixuan Xiang, Boan Zhong, Huijun Tan, Rahul Navik, Zhiyuan Liu, Yaping Zhao. Improved Dispersibility of Graphene in an Aqueous Solution by Reduced Graphene Oxide Surfactant: Experimental Verification and Density Functional Theory Calculation. Langmuir 2022, 38 (27) , 8222-8231. https://doi.org/10.1021/acs.langmuir.2c00552
Jinwu Hu, Caihong Fang, Xiaomin Jiang, Deliang Zhang, Zhiqing Cui. Ultrathin and Porous 2D PtPdCu Nanoalloys as High-Performance Multifunctional Electrocatalysts for Various Alcohol Oxidation Reactions. Inorganic Chemistry 2022, 61 (24) , 9352-9363. https://doi.org/10.1021/acs.inorgchem.2c01257
Marziya Rizvi Husnu Gerengi Preeti Gupta . Functionalization of Nanomaterials: Synthesis and Characterization. , 1-26. https://doi.org/10.1021/bk-2022-1418.ch001
Sarita Rai Mridula Guin Anindita De N. B. Singh . Functionalized Nanomaterials: Basics, Properties and Applications. , 27-66. https://doi.org/10.1021/bk-2022-1418.ch002
Ja-Jung Koo, Zee Hwan Kim. Radical-Mediated C–C Coupling of Alcohols Induced by Plasmonic Hot Carriers. The Journal of Physical Chemistry Letters 2022, 13 (16) , 3740-3747. https://doi.org/10.1021/acs.jpclett.2c00798
Yungen Wu, Daizong Ji, Changhao Dai, Derong Kong, Yiheng Chen, Liqian Wang, Mingquan Guo, Yunqi Liu, Dacheng Wei. Triple-Probe DNA Framework-Based Transistor for SARS-CoV-2 10-in-1 Pooled Testing. Nano Letters 2022, 22 (8) , 3307-3316. https://doi.org/10.1021/acs.nanolett.2c00415
Ilhem Bargaoui, Nabila Bitri, Jean-Michel Ménard. A Comparative Investigation of Chemically Reduced Graphene Oxide Thin Films Deposited via Spray Pyrolysis. ACS Omega 2022, 7 (14) , 11973-11979. https://doi.org/10.1021/acsomega.2c00108
Fa-Yuan Ge, Qi Yan, Shuai Liang, Xin-De Duan, He-Gen Zheng. From Hydrogen Bond to van der Waals Force: Molecular Scalpel Strategy to Exfoliate a Two-Dimensional Metal–Organic Nanosheet. Inorganic Chemistry 2022, 61 (14) , 5465-5468. https://doi.org/10.1021/acs.inorgchem.1c03755
Xifeng Liu, Linli Li, Bipin Gaihre, Sungjo Park, Yong Li, Andre Terzic, Benjamin D. Elder, Lichun Lu. Scaffold-Free Spheroids with Two-Dimensional Heteronano-Layers (2DHNL) Enabling Stem Cell and Osteogenic Factor Codelivery for Bone Repair. ACS Nano 2022, 16 (2) , 2741-2755. https://doi.org/10.1021/acsnano.1c09688
Hao Wang, Mingqi Chen, Yimin Sun, Lian Xu, Fei Li, Jinsong Han. Machine Learning-Assisted Pattern Recognition of Amyloid Beta Aggregates with Fluorescent Conjugated Polymers and Graphite Oxide Electrostatic Complexes. Analytical Chemistry 2022, 94 (6) , 2757-2763. https://doi.org/10.1021/acs.analchem.1c03623
Lili Xu, Renmin Liu, Zhaofang Li, Moju Li, Min Zhao, Yingjie Li, Guiyue Hou, Aifeng Li, Hongbo Suo. Ionic Liquid Modification Optimizes the Interface between Lipase and Magnetic GO for Enhancing Biocatalysis. Industrial & Engineering Chemistry Research 2022, 61 (3) , 1277-1284. https://doi.org/10.1021/acs.iecr.1c04396
Francisco Hidalgo, Alberto Rubio-Ponce, Cecilia Noguez. Cysteine Adsorption on Twisted-Bilayer Graphene. The Journal of Physical Chemistry C 2021, 125 (49) , 27314-27322. https://doi.org/10.1021/acs.jpcc.1c08649
Qingfang Han, Jinbo Pang, Yufen Li, Baojun Sun, Bergoi Ibarlucea, Xiaoyan Liu, Thomas Gemming, Qilin Cheng, Shu Zhang, Hong Liu, Jingang Wang, Weijia Zhou, Gianaurelio Cuniberti, Mark H. Rümmeli. Graphene Biodevices for Early Disease Diagnosis Based on Biomarker Detection. ACS Sensors 2021, 6 (11) , 3841-3881. https://doi.org/10.1021/acssensors.1c01172
Zhuquan Huang, Jiaqi Wang, Suwei Lu, Hun Xue, Qinghua Chen, Min-Quan Yang, Qingrong Qian. Insight into the Real Efficacy of Graphene for Enhancing Photocatalytic Efficiency: A Case Study on CVD Graphene-TiO2 Composites. ACS Applied Energy Materials 2021, 4 (9) , 8755-8764. https://doi.org/10.1021/acsaem.1c00731
Daniela K. Jacquelín, Federico A. Soria, Patricia A. Paredes-Olivera, Eduardo M. Patrito. Reactive Force Field-Based Molecular Dynamics Simulations on the Thermal Stability of Trimesic Acid on Graphene: Implications for the Design of Supramolecular Networks. ACS Applied Nano Materials 2021, 4 (9) , 9241-9253. https://doi.org/10.1021/acsanm.1c01759
Shamim Ahmed Hira, Mohammad Yusuf, Dicky Annas, Saravanan Nagappan, Sehwan Song, Sungkyun Park, Kang Hyun Park. Recent Advances on Conducting Polymer-Supported Nanocomposites for Nonenzymatic Electrochemical Sensing. Industrial & Engineering Chemistry Research 2021, 60 (37) , 13425-13437. https://doi.org/10.1021/acs.iecr.1c02043
Kang-Qiang Lu, Yue-Hua Li, Zi-Rong Tang, Yi-Jun Xu. Roles of Graphene Oxide in Heterogeneous Photocatalysis. ACS Materials Au 2021, 1 (1) , 37-54. https://doi.org/10.1021/acsmaterialsau.1c00022
Long Jiao, Fuquan Ma, Xiaotong Wang, Zhimin Li, Zhongai Hu, Qing Yin. Quinolinediol Molecule Electrode and MXene for Asymmetric Supercapacitors with Efficient Energy Storage. ACS Applied Energy Materials 2021, 4 (8) , 7811-7820. https://doi.org/10.1021/acsaem.1c01169
Yang Gang, Erik Sarnello, John Pellessier, Siyuan Fang, Manuel Suarez, Fuping Pan, Zichen Du, Peng Zhang, Lingzhe Fang, Yuzi Liu, Tao Li, Hong-Cai Zhou, Yun Hang Hu, Ying Li. One-Step Chemical Vapor Deposition Synthesis of Hierarchical Ni and N Co-Doped Carbon Nanosheet/Nanotube Hybrids for Efficient Electrochemical CO2 Reduction at Commercially Viable Current Densities. ACS Catalysis 2021, 11 (16) , 10333-10344. https://doi.org/10.1021/acscatal.1c01864
Muserref A Ocsoy, Sadi Yusufbeyoglu, Nilay Ildiz, Ahmet Ulgen, Ismail Ocsoy. DNA Aptamer-Conjugated Magnetic Graphene Oxide for Pathogenic Bacteria Aggregation: Selective and Enhanced Photothermal Therapy for Effective and Rapid Killing. ACS Omega 2021, 6 (31) , 20637-20643. https://doi.org/10.1021/acsomega.1c02832
Duan-Chao Wang, Hou-Yong Yu, Dongming Qi, Yuhang Wu, Lumin Chen, Ziheng Li. Confined Chemical Transitions for Direct Extraction of Conductive Cellulose Nanofibers with Graphitized Carbon Shell at Low Temperature and Pressure. Journal of the American Chemical Society 2021, 143 (30) , 11620-11630. https://doi.org/10.1021/jacs.1c04710
Mawin J. Martinez Jimenez, Alba Avila, Anerise de Barros, Elvis Oswaldo Lopez, Fernando Alvarez, Antonio Riul, Jr, Jaime Andres Perez-Taborda. Polyethyleneimine-Functionalized Carbon Nanotube/Graphene Oxide Composite: A Novel Sensing Platform for Pb(II) Acetate in Aqueous Solution. ACS Omega 2021, 6 (28) , 18190-18199. https://doi.org/10.1021/acsomega.1c02085
Adam R. Brill, Alonit Kafri, Pranab K. Mohapatra, Ariel Ismach, Graham de Ruiter, Elad Koren. Modulating the Optoelectronic Properties of MoS2 by Highly Oriented Dipole-Generating Monolayers. ACS Applied Materials & Interfaces 2021, 13 (27) , 32590-32597. https://doi.org/10.1021/acsami.1c09035
Shao-Xiong Lennon Luo, Richard Y. Liu, Sungsik Lee, Timothy M. Swager. Electrocatalytic Isoxazoline–Nanocarbon Metal Complexes. Journal of the American Chemical Society 2021, 143 (27) , 10441-10453. https://doi.org/10.1021/jacs.1c05439
Takahiro Tsukamoto, Nobumitsu Hirose, Akifumi Kasamatsu, Toshiaki Matsui, Yoshiyuki Suda. Direct Growth of Patterned Ge on Insulators Using Graphene. The Journal of Physical Chemistry C 2021, 125 (25) , 14117-14121. https://doi.org/10.1021/acs.jpcc.1c03567
Tomokazu Umeyama, Han Xu, Tomoya Ohara, Yusuke Tsutsui, Shu Seki, Hiroshi Imahori. Photodynamic and Photoelectrochemical Properties of Few-Layered Bismuthene Film on SnO2 Electrode and Its Hybridization with C60. The Journal of Physical Chemistry C 2021, 125 (25) , 13954-13962. https://doi.org/10.1021/acs.jpcc.1c03574
Fuquan Ma, Zhongai Hu, Long Jiao, Xiaotong Wang, Yuanyuan He, Yuying Yang, Zhimin Li. Organic Molecule-Functionalized Reduced Graphene Oxide for All-Carbon Asymmetric Supercapacitor Applications. ACS Applied Energy Materials 2021, 4 (6) , 5493-5503. https://doi.org/10.1021/acsaem.1c00150
Tutku Beduk, Duygu Beduk, José Ilton de Oliveira Filho, Figen Zihnioglu, Candan Cicek, Ruchan Sertoz, Bilgin Arda, Tuncay Goksel, Kutsal Turhan, Khaled N. Salama, Suna Timur. Rapid Point-of-Care COVID-19 Diagnosis with a Gold-Nanoarchitecture-Assisted Laser-Scribed Graphene Biosensor. Analytical Chemistry 2021, 93 (24) , 8585-8594. https://doi.org/10.1021/acs.analchem.1c01444
Cho Rok Jin, Jee Young Kim, Da Hee Kim, Min Seo Jeon, Yoon-E Choi. In Vivo Monitoring of Intracellular Metabolite in a Microalgal Cell Using an Aptamer/Graphene Oxide Nanosheet Complex. ACS Applied Bio Materials 2021, 4 (6) , 5080-5089. https://doi.org/10.1021/acsabm.1c00322
Yuxin Chen, Po Hu, Zhiyun Huang, Jinyu Wang, Haiyang Song, Xi Chen, Xiao Lin, Tianmin Wu, Xiaodi Tan. Significant Enhancement of the Polarization Holographic Performance of Photopolymeric Materials by Introducing Graphene Oxide. ACS Applied Materials & Interfaces 2021, 13 (23) , 27500-27512. https://doi.org/10.1021/acsami.1c07390
Syed Farooq Adil, Mohammed Rafi Shaik, Fahd A. Nasr, Ali S. Alqahtani, Mohammad Z. Ahmed, Wajhul Qamar, Mufsir Kuniyil, Adibah Almutairi, Abdulrahman Alwarthan, Mohammed Rafiq H. Siddiqui, Mohammad Rafe Hatshan, Mujeeb Khan. Enhanced Apoptosis by Functionalized Highly Reduced Graphene Oxide and Gold Nanocomposites in MCF-7 Breast Cancer Cells. ACS Omega 2021, 6 (23) , 15147-15155. https://doi.org/10.1021/acsomega.1c01377
Lin Mei, Yanmei Shi, Fengyi Cao, Xuan Liu, Xiu-Min Li, Zhenlong Xu, Zhiqiang Miao. PEGylated Phthalocyanine-Functionalized Graphene Oxide with Ultrahigh-Efficient Photothermal Performance for Triple-Mode Antibacterial Therapy. ACS Biomaterials Science & Engineering 2021, 7 (6) , 2638-2648. https://doi.org/10.1021/acsbiomaterials.1c00178
Daniel González-Muñoz, Ana Martín-Somer, Klara Strobl, Silvia Cabrera, Pedro J. De Pablo, Sergio Díaz-Tendero, Matías Blanco, José Alemán. Enhancing Visible-Light Photocatalysis via Endohedral Functionalization of Single-Walled Carbon Nanotubes with Organic Dyes. ACS Applied Materials & Interfaces 2021, 13 (21) , 24877-24886. https://doi.org/10.1021/acsami.1c04679
Yaqi Cao, Junshi Zhang, Lan Wang, Mingjun Cen, Wenchao Peng, Yang Li, Fengbao Zhang, Juan Tan, Xiaobin Fan. Dual-Functionalized Covalent Triazine Framework Nanosheets as Hierarchical Nonviral Vectors for Intracellular Gene Delivery. ACS Applied Nano Materials 2021, 4 (5) , 4948-4955. https://doi.org/10.1021/acsanm.1c00477
Gunwoo Kim, Jeongjae Lee, Tao Liu, Clare P. Grey. Characterizing Nitrogen Sites in Nitrogen-Doped Reduced Graphene Oxide: A Combined Solid-State 15N NMR, XPS, and DFT Approach. The Journal of Physical Chemistry C 2021, 125 (19) , 10558-10564. https://doi.org/10.1021/acs.jpcc.1c02669
Aloke Bapli, Aninda Chatterjee, Rajesh Kumar Gautam, Rabindranath Jana, Debabrata Seth. Modulation of the Protein–Ligand Interaction in the Presence of Graphene Oxide: a Detailed Spectroscopic Study. Langmuir 2021, 37 (16) , 5034-5048. https://doi.org/10.1021/acs.langmuir.1c00534
Ruicong Wang, Kun Lan, Runfeng Lin, Xinxin Jing, Chin-Te Hung, Xingmiao Zhang, Liangliang Liu, Yi Yang, Gang Chen, Xiaoguo Liu, Chunhai Fan, Ahmed Mohamed El-Toni, Aslam Khan, Yun Tang, Dongyuan Zhao. Precisely Controlled Vertical Alignment in Mesostructured Carbon Thin Films for Efficient Electrochemical Sensing. ACS Nano 2021, 15 (4) , 7713-7721. https://doi.org/10.1021/acsnano.1c01367
Andreas Tsiamis, Francisco Diaz Sanchez, Niklas Hartikainen, Michael Chung, Srinjoy Mitra, Ying Chin Lim, Huey Ling Tan, Norbert Radacsi. Graphene Wrapping of Electrospun Nanofibers for Enhanced Electrochemical Sensing. ACS Omega 2021, 6 (16) , 10568-10577. https://doi.org/10.1021/acsomega.0c05823
Ali Motaee, Soheila Javadian, Mahnaz Khosravian. Influence of Adsorption Energy in Graphene Production via Surfactant-Assisted Exfoliation of Graphite: A Graphene-Dispersant Design. ACS Applied Nano Materials 2021, 4 (4) , 3545-3556. https://doi.org/10.1021/acsanm.1c00043
Bowen Zheng, Grace X. Gu. Prediction of Graphene Oxide Functionalization Using Gradient Boosting: Implications for Material Chemical Composition Identification. ACS Applied Nano Materials 2021, 4 (3) , 3167-3174. https://doi.org/10.1021/acsanm.1c00384
Yanxiao Li, Zhekun Peng, Natalie J. Holl, Md. Rifat Hassan, John M. Pappas, Congjie Wei, Omid Hoseini Izadi, Yang Wang, Xiangyang Dong, Cheng Wang, Yue-Wern Huang, DongHyun Kim, Chenglin Wu. MXene–Graphene Field-Effect Transistor Sensing of Influenza Virus and SARS-CoV-2. ACS Omega 2021, 6 (10) , 6643-6653. https://doi.org/10.1021/acsomega.0c05421
Hyungjun Park, Dong Jun Shin, Junhua Yu. Categorization of Quantum Dots, Clusters, Nanoclusters, and Nanodots. Journal of Chemical Education 2021, 98 (3) , 703-709. https://doi.org/10.1021/acs.jchemed.0c01403
Ikumi Akita, Yohei Ishida, Tetsu Yonezawa. Direct Imaging of Individual Organic Molecules in Supramolecular Assembly Strongly Fixed via Multivalent Electrostatic Interactions. The Journal of Physical Chemistry C 2021, 125 (8) , 4917-4923. https://doi.org/10.1021/acs.jpcc.1c00738
Margarita Vázquez-González, Itamar Willner. Aptamer-Functionalized Micro- and Nanocarriers for Controlled Release. ACS Applied Materials & Interfaces 2021, 13 (8) , 9520-9541. https://doi.org/10.1021/acsami.0c17121
Adam R. Brill, Santu Biswas, Maytal Caspary Toroker, Graham de Ruiter, Elad Koren. Dipole-Induced Raman Enhancement Using Noncovalent Azobenzene-Functionalized Self-Assembled Monolayers on Graphene Terraces. ACS Applied Materials & Interfaces 2021, 13 (8) , 10271-10278. https://doi.org/10.1021/acsami.0c20454
Mohit Saraf, Mohammad Tavakkoli Yaraki, Prateek, Yen Nee Tan, Raju Kumar Gupta. Insights and Perspectives Regarding Nanostructured Fluorescent Materials toward Tackling COVID-19 and Future Pandemics. ACS Applied Nano Materials 2021, 4 (2) , 911-948. https://doi.org/10.1021/acsanm.0c02945
Kishan Thodkar, Pierre-Andre Cazade, Frank Bergmann, Eloisa Lopez-Calle, Damien Thompson, Dieter Heindl. Self-Assembled Pyrene Stacks and Peptide Monolayers Tune the Electronic Properties of Functionalized Electrolyte-Gated Graphene Field-Effect Transistors. ACS Applied Materials & Interfaces 2021, 13 (7) , 9134-9142. https://doi.org/10.1021/acsami.0c18485
Andrew D. Pendergast, Christophe Renault, Jeffrey E. Dick. Correlated Optical–Electrochemical Measurements Reveal Bidirectional Current Steps for Graphene Nanoplatelet Collisions at Ultramicroelectrodes. Analytical Chemistry 2021, 93 (5) , 2898-2906. https://doi.org/10.1021/acs.analchem.0c04409
Yawen Miao, Kai Chen, Xu Zhang, Zhijun Xu, Xiaoning Yang. Water-Mediated Attractive Interaction between Negatively Charged GO Nanosheets at the Air–Water Interface. The Journal of Physical Chemistry C 2021, 125 (1) , 845-853. https://doi.org/10.1021/acs.jpcc.0c07429
Qun Su, Xue V. Zhen, Justin T. Nelson, Ruixue Li, Philippe Bühlmann, Gregory Sherwood, Steven J. Koester. Ultraclean Graphene Transfer Using a Sacrificial Fluoropolymer Nanolayer: Implications for Sensor and Electronic Applications. ACS Applied Nano Materials 2020, 3 (12) , 11998-12007. https://doi.org/10.1021/acsanm.0c02482
Yong Li, Jialin Lu, Jing Zhang, Xiaohui Zhu, Jinliang Liu, Yong Zhang. Phase-Change Nanotherapeutic Agents Based on Mesoporous Carbon for Multimodal Imaging and Tumor Therapy. ACS Applied Bio Materials 2020, 3 (12) , 8705-8713. https://doi.org/10.1021/acsabm.0c01102
Won Chang Lee, Seok Min Kang, Byung Chul Lee, Sang Eun Kim, Dong Wook Kim. Multifunctional Crown-5-calix[4]arene-based Phase-Transfer Catalysts for Aromatic 18F-Fluorination. Organic Letters 2020, 22 (24) , 9551-9555. https://doi.org/10.1021/acs.orglett.0c03604
Piramon Hampitak, Thomas A. Jowitt, Daniel Melendrez, Maryline Fresquet, Patrick Hamilton, Maria Iliut, Kaiwen Nie, Ben Spencer, Rachel Lennon, Aravind Vijayaraghavan. A Point-of-Care Immunosensor Based on a Quartz Crystal Microbalance with Graphene Biointerface for Antibody Assay. ACS Sensors 2020, 5 (11) , 3520-3532. https://doi.org/10.1021/acssensors.0c01641
Kuang Liang, Ewa M. Spiesz, Dominik T. Schmieden, An-Wu Xu, Anne S. Meyer, Marie-Eve Aubin-Tam. Bioproduced Polymers Self-Assemble with Graphene Oxide into Nanocomposite Films with Enhanced Mechanical Performance. ACS Nano 2020, 14 (11) , 14731-14739. https://doi.org/10.1021/acsnano.0c00913

Load more citations

Download PDF

Abstract

High Resolution Image

Download MS PowerPoint Slide

Figure 1

Figure 1. A layer of graphene peeled away from the graphite found in a common pencil.

High Resolution Image

Download MS PowerPoint Slide

Figure 2

Figure 2. Model of the SiC structure in which three carbon layers of SiC are collapsed under evaporation of Si to form one graphite layer: (− – −) unit mesh of SiC (0001); (- - -) unit mesh of the graphite layer; (○) C atoms from the collapse of three carbon layers of SiC; and (●) C atoms of the monocrystalline graphite top layer. Reprinted with permission from ref 10. Copyright 1975 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 3

Figure 3. Oxidation of graphene sheet to form graphene oxide.

High Resolution Image

Download MS PowerPoint Slide

Figure 4

Figure 4. Schematic representation of noncovalent interactions of G/GO with selected application-important species involving MoS₂, aromatic polymers, proteins, core–shell nanoparticle, nanotube, quantum dot, ellipticine (drug/photoluminescence probe), DNA segment, and fullerenes (clockwise from top).

High Resolution Image

Download MS PowerPoint Slide

Figure 5

Figure 5. π–π stacking face-to-face (left), slipped (middle), and C–H···π (right) type from benzyl molecules where the gray atoms represent carbon and orange represents hydrogen for benzene or other atoms for different derivatives.

High Resolution Image

Download MS PowerPoint Slide

Figure 6

Figure 6. Idealized π–π or C–H···π interactions from benzene, naphthalene, or pyrene molecules above and below the basal plane of graphene.

High Resolution Image

Download MS PowerPoint Slide

Figure 7

Figure 7. Schematic representation of both hydrogen bonds and/or π–π stacking with GO.

High Resolution Image

Download MS PowerPoint Slide

Figure 8

Figure 8. Molecules of 4-n-octyl-4′-cyanobiphenyl aligned on the surface of HOPG. Reprinted with permission from ref 45. Copyright 1988 Nature Publishing Group.

High Resolution Image

Download MS PowerPoint Slide

Figure 9

Figure 9. Scanning tunneling microscopy (STM) images of trimesic acid on the surface of HOPG in (a) honeycomb, (b) flower, and (c) close packing motifs. Panels (a) and (b) reprinted with permission from ref 46. Copyright 2002 Wiley-VCH. Panel (c) reprinted with permission from ref 49. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 10

Figure 10. (a) Upright arrangement of F4-TCNA on EG/SiC and (b) parallel with the EG/Ru surface. Panel (a) reprinted with permission from ref 52. Copyright 2010 American Physical Society. Panel (b) reprinted with permission from ref 53. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 11

Figure 11. Monolayer of PTCDA adsorbed on EG/SiC(0001). Reprinted with permission from ref 54. Copyright 2009 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 12

Figure 12. (a) Supramolecular chains of PTCDI and (b) an alkyl PTCDI derivative absorbed on EG/SiC. Reprinted with permission from ref 58. Copyright 2010 Wiley-VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 13

Figure 13. (a) Schematic setup used for measuring the π–π interactions between pyrene and graphite in aqueous medium by single molecule force microscopy. (b) Force curves of pyrene-modified tips desorbed from graphite substrate in aqueous medium under a retraction velocity of 500 nm/s and at room temperature. Reprinted with permission from ref 74. Copyright 2007 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 14

Figure 14. Aqueous dispersion of (a) rGO, (b) rGO-PDI, and (c) rGO-PyS after centrifugation. (d) G-bands of the Raman spectra of the rGO, rGO-PDI, and rGO-PyS hybrids. Reprinted with permission from ref 78. Copyright 2009 Wiley VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 15

Figure 15. AFM images and cross-section analysis of (a) rGO/PyS and (b) rGO/PDI on mica. Reprinted with permission from ref 78. Copyright 2009 Wiley VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 16

Figure 16. UV–vis absorption change of AlPcS₄ (15 μm for rGO and 3 μm for GO) by the interaction with increased amount of (a) rGO and (b) GO. Reprinted with permission from ref 81. Copyright 2014 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 17

Figure 17. (a) PL of AlPcS₄ (15 μM) in the presence of rGO with excitation at 610 nm. (b) The plot of the intensity of quenching with the concentration of rGO, GO, and SWNTs. Reprinted with permission from ref 81. Copyright 2014 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 18

Figure 18. (a) Structure of the tetrapyrene derivative. (b) The resulting hybrid is highly dispersible in water (1.5 mg mL^–1). (c) Schematic representation of exfoliation process. (d) Absorption and (e) emission spectra of 1 and 1-G in 0.2 wt % (MeOH/H₂O); λ_ex = 340 nm. Reprinted with permission from ref 86. Copyright 2011 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 19

Figure 19. Four pyrene derivatives with increasing number of sulfonic groups used for the study of graphite exfoliation and G stabilization. Reprinted with permission from ref 92. Copyright 2013 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 20

Figure 20. Porphyrin derivatives with sulfonate and ammonium groups. Reprinted with permission from ref 104. Copyright 2010 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 21

Figure 21. Schematic representation of pyridinium-functionalized porphyrin interacting with G by π stacking. Reprinted with permission from ref 105. Copyright 2009 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 22

Figure 22. π–π interaction of phthalocyanine TSCuPc with G (GR in the image). Reprinted with permission from ref 108. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 23

Figure 23. UV–vis spectra of TSCuPc and the hybrid G/TSCuPc. Reprinted with permission from ref 108. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 24

Figure 24. Time-dependent photothermal curves of G/TSCuPc and TSCuPc solutions. Reprinted with permission from ref 108. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 25

Figure 25. PL spectra of the rGO/Rb hybrid and rGO. Reprinted with permission from ref 112. Copyright 2013 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 26

Figure 26. Transformation of the hydrophilic rGO to an organophilic rGO/polymer composite using an amine terminated polystyrene. Reprinted with permission from ref 121. Copyright 2010 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 27

Figure 27. Interaction of Kevlar with graphene nanoribbons. Reprinted with permission from ref 122. Copyright 2014 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 28

Figure 28. (a) Synthetic procedure of adding aromatic end groups to polyethylene glycol and (b) schematic presentation of the f-PEG/rGO composite formation. Reprinted with permission from ref 123. Copyright 2015 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 29

Figure 29. Electrical conductivity of the PEG/rGO composites with different polymer loadings. Reprinted with permission from ref 123. Copyright 2015 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 30

Figure 30. Preparation of a composite material with waterborn polyurethane and surfactant covered rGO. Reprinted with permission from ref 128. Copyright 2013 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 31

Figure 31. Tapping mode AFM images of horseradish peroxidase (HRP) immobilized on GO at (a) small and (b) large enzyme loadings. (c) Schematic model of the GO-bound HRP. (d) Initial reaction rates of GO-bound HRP versus HRP concentration. Reprinted with permission from ref 131. Copyright 2010 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 32

Figure 32. Deposition of tryptophane/G on a glassy carbon electrode (GCE) for the determination of dopamine. Reprinted with permission from ref 136. Copyright 2014 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 33

Figure 33. Schematic representation of the target-induced fluorescence change of a dye labeled ssDNA/GO hybrid. FAM is the fluorescein-based fluorescent dye. Reprinted with permission from ref 145. Copyright 2009 Wiley-VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 34

Figure 34. Electrochemical behavior of GO nanoplatelets after the interaction with ssDNA modified electrodes exposed to (a) complementary, (b) one-mismatch, and (c) noncomplementary targets. Reprinted with permission from ref 150. Copyright 2012 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 35

Figure 35. AFM images showing (a) the formation of fibrils after aggregation in a solution of Aβ_33–44 peptide and (b) the absence of fibrils when in the peptide solution with GO nanoplatelets. Reprinted with permission from ref 154. Copyright 2015 Wiley VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 36

Figure 36. (a) Molecular structure of Ramisol and the hybrid with a G layer. (b) Dispersion of the hybrid in water with different ratios. Reprinted with permission from ref 155. Copyright 2015 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 37

Figure 37. (a) Molecular structure of hypocrellin A and B. (b) Schematic representation of the GO/HB hybrid. Reprinted with permission from ref 156. Copyright 2012 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 38

Figure 38. (a) Neutral and protonated forms of ellipticine. (b) Photoluminescence of E free and after its π–π interaction with GO and changes in the presence of HSA, DNA, RNA, or HSA and DNA. Reprinted with permission from ref 162. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 39

Figure 39. Pyrene links graphene and glucose oxidase through π–π stacking. Reprinted with permission from ref 163. Copyright 2015 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 40

Figure 40. Pyrene interconnection between G and gold electrode. Reprinted with permission from ref 164. Copyright 2013 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 41

Figure 41. (a) Structure of a cyclophane with diazapyrenium units (CBDAP⁴⁺), (b) photo of CBDAP⁴⁺/GO gel, and (c) representation of the possible position of cyclophane/CBDAP between GO layers. Reprinted with permission from ref 167. Copyright 2014 Wiley-VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 42

Figure 42. Schematic representation of aerogel formation toward the rGO/SWNT hybrid. Reprinted with permission from ref 169. Copyright 2015 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 43

Figure 43. (a) Formation of G/MWNTs-f-OH hybrid and (b) its dispersion in water. (c) Graphene precipitate without MWNTs-f-OH following the same procedure and (d) the hybrid in ethylene glycol at high concentration. Reprinted with permission from ref 170. Copyright 2015 Wiley-VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 44

Figure 44. Schematic representation of the two possible conformations of the pyrene-PCBM/rGO hybrid: (a) C₆₀ is attached on the graphenic surface simultaneously with the pyrene stacking, and (b) C₆₀ is kept far from G and pyrene. Reprinted with permission from ref 176. Copyright 2013 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 45

Figure 45. SEM and TEM micrographs of (a,d) bulk nanodiamonds, (b,e) few-layer graphene (FLG), and (c,f) the FLG/NDs hybrid. Reprinted with permission from ref 178. Copyright 2015 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 46

Figure 46. Schematic representation that shows how the removal of oxidative debris is correlated with the reduced electroactivity of GO in cyclic voltametry. Reprinted with permission from ref 182. Copyright 2014 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 47

Figure 47. (a–c) Low-resolution TEM images of BN, MoS₂, and WS₂ layered flakes. (d–f) High-resolution TEM images of BN, MoS₂, and WS₂ monolayers. The insets show fast Fourier transforms of the images. (g–i) Butterworth-filtered images of sections of the images in panels (d), (e), and (f), respectively. Reprinted with permission from ref 190. Copyright 2011 American Association for the Advancement of Science.

High Resolution Image

Download MS PowerPoint Slide

Figure 48

Figure 48. Schematic representation of three similar liquid exfoliation processes based on (a) intercalation, (b) ion exchange, and (c) ultrasonic exfoliation. Reprinted with permission from ref 69. Copyright 2013 American Association for the Advancement of Science.

High Resolution Image

Download MS PowerPoint Slide

Figure 49

Figure 49. Schematic representation of the device with G and MoS₂. Reprinted with permission from ref 198. Copyright 2013 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 50

Figure 50. (a) X-ray diffraction patterns and (b) Raman spectra of bare WS₂ and the hybrids WS₂/rGO in two different ratios. Reprinted with permission from ref 203. Copyright 2013 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 51

Figure 51. Schematic representation of a field-effect transistor constructed by graphene, MoS₂, and h-BN layers. Reprinted with permission from ref 204. Copyright 2014 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 52

Figure 52. Schematic of the synthesis method used to prepare symmetrically deposited CVD graphene sheets with different metals on either side. Reprinted with permission from ref 224. Copyright 2015 Wiley-VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 53

Figure 53. Schematic showing the synthesis of the Ni₃S₂/rGO 3D framework. Reprinted with permission from ref 237. Copyright 2013 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 54

Figure 54. Synthesis of (a) Pt nanodendrites and (b) Pt nanoclusters deposited onto GO using DNA as a template. Panel (a) reprinted with permission from ref 246. Copyright 2013 American Chemical Society. Panel (b) reprinted with permission from ref 247. Copyright 2013 Nature Publishing Group.

High Resolution Image

Download MS PowerPoint Slide

Figure 55

Figure 55. Polarization curves obtained for the Pt–Pd–rGO EHER catalysts, with different Pt thickness and equal Pd loading amounts. Pt–Pd–rGO I, Pt–Pd–rGO II, and Pt–Pd–rGO III show Pt layer thicknesses of 0.8, 1.8, and 3.2 nm, respectively. Reprinted with permission from ref 262. Copyright 2014 Wiley-VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 56

Figure 56. Charge carrier density in a graphene sensor versus hydrogen concentration. Reprinted with permission from ref 271. Copyright 2010 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 57

Figure 57. Synthesis of rGO/Pt–Pd supported catalysts. Reprinted with permission from ref 272. Copyright 2014 Elsevier B.V.

High Resolution Image

Download MS PowerPoint Slide

Figure 58

Figure 58. Capacity of the Si/rGO material at various current densities upon cycling. Reprinted with permission from ref 285. Copyright 2013 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 59

Figure 59. Cycling performance of Co₃O₄ NPs (nanoparticles), Co₃O₄ NFs (nanofibers), Co₃O₄ NF/rGO composite, and Co₃O₄ NFs/GNF (graphene) materials under a specific capacity limit of 1000 mA h g^–1 in a voltage window between 4.35 and 2.0 V at a current density of 200 mA g^–1. Reprinted with permission from ref 294. Copyright 2013 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 60

Figure 60. (a) Magnetic deformation of the magnetic Fe₃O₄/rGO aerogel, (b) I–V curve and thermal conductivity stability of the aerogel, and (c) change in the electrical resistance of the aerogel as a function of the magnetic field-induced deformation. Reprinted with permission from ref 298. Copyright 2015 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 61

Figure 61. (a) Charge–discharge voltage profiles of the T-200 hybrid cycled at 1.0–3.0 V at a current density of 0.1 A g^–1, (b) rate performances of T-200, C1, and C2 at various current densities, and (c) cycling performance of T-150, T-200, T-240, C1, and C2 at a current density of 0.1 A g^–1. Reprinted with permission from ref 339. Copyright 2015 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 62

Figure 62. Synthetic methods used to produce SAC–rGO (right bottom) and rGO (left bottom). A schematic of the electrochemical device used to measure the supercapacitance of the material is also shown. Reprinted with permission from ref 345. Copyright 2015 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 63

Figure 63. G–TiO₂ hybrid-based solar cell performance under simulated AM 1.5, 106.5 mW/cm² solar irradiation (red line), and that in the dark (black line). Reprinted with permission from ref 351. Copyright 2014 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 64

Figure 64. DSSCs performance with NDG/CoS, G/CoS, NDG, and Pt as CEs. Reprinted with permission from ref 359. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 65

Figure 65. (a) HER polarization curves for catalysts, (b) Tafel plots, (c) stability test of Mo₂C–rGO hybrid, and (d) time dependence of current density of Mo₂C–rGO hybrid at an applied potential of 140 mV. Reprinted with permission from ref 373. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 66

Figure 66. Synthesis of AC–GO and AC–rGO hybrids. The blue platelets represent aminoclay, while the brown and gray sheets show GO and rGO, respectively. Reprinted with permission from ref 377. Copyright 2013 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 67

Figure 67. (a) Schematic diagram of the basic concept of the experiment: proper pH is used to affect charge attraction/repulsion between the GO sheets and Fe₂O₃ nanoparticles. Fe₂O₃ nanoparticles separated from solution or dispersion by applied magnetic field. (b) Zeta potentials of GO and Fe₂O₃ nanoparticles. Reprinted with permission from ref 378. Copyright 2015 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 68

Figure 68. Conductivity of various hybrid materials of G/rGO. Reprinted with permission from ref 394. Copyright 2015 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 69

Figure 69. Electric transport calibrations of G and heterostructure (H) electric field devices. (a) Optical microscope image of the H-device. (b) Raman mapping of 2D, G, and D peaks. (c) G resistivity at various position contacts (P1–P4) versus back-gate voltage (U_BG) at room temperature.(d) Electric charge mobility of G in H- and G-devices versus carrier concentration (n) at room temperature.(e) The electric charge mobility in H- and G-devices at n = −2 × 10¹² cm^–2. (f) Conductivity of G in H3 and G1 in the vicinity of their charge neutrality points at room temperature. (g) Electrons and holes coexistence represented by Hall coefficient calibrations for devices H3 and G1 at a magnetic field of 1 T and a temperature of 250 mK. Dashed lines showed the single-particle model for holes and electrons. Reprinted with permission from ref 397. Copyright 2014 Wiley-VCH.

High Resolution Image

Download MS PowerPoint Slide

Figure 70

Figure 70. Photovoltaic and impedance performances of the DSSCs with different G/TiO₂ photoanodes. Reprinted with permission from ref 408. Copyright 2015 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 71

Figure 71. General mechanism for H₂ evolution from photocatalytic water splitting by the g-C₃N₄/rGO-3 hybrid, in which g-C₃N₄ acts as an electron sink providing the separation of electron–hole pairs and collects the electrons injected from the photoexcited rGO-3 for subsequent H₂ production from reduction of H₂O. Reprinted with permission from ref 409. Copyright 2015 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 72

Figure 72. Capture of circulating tumor cells (CTCs) from breast cancer: (a) patient no. 6 (Br6); (b) patient no. 2 (Br2); and (c) quantification of CTCs. Capture of CTC from pancreatic cancer: (d) patient no. 2 (Pan2); (e) patient no. 9 (Pan9); and (f) quantification of CTCs. Capture of CTC from lung cancer: (g) patient no. 3 (L3); (h) quantification of CTCs; and (i) gene expression of captured CTCs via qRT-PCR. Reprinted with permission from ref 421. Copyright 2013 Nature Publishing Group.

High Resolution Image

Download MS PowerPoint Slide

Figure 73

Figure 73. SPRi sensing profiles, differential images, and line profiles for detection in human serum: (a,b) Direct detection, (c,d) antibody-conjugated PDA–rGO for signal amplification, and (e,f) sequential Au coated. The red color line in panels (a), (c), and (e) displayed the results on the sensing point, and the black lines are collected from the control point. The blue boundaries in (b), (d), and (f) showed the four sensing points on the SPRi chip. Reprinted with permission from ref 424. Copyright 2014 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 74

Figure 74. Fluorescence images of mouse fibroblast NIH/3T3 cells containing (a) CDs and (b,c) GO/CDs hybrids, demonstrating selective labeling of nuclei and cytoplasm. For pure carbon dots, a fast endocytosis occurred, and carbon dots readily entered cell nuclei (panel (a)). However, if GO/CDs hybrids were employed, penetration into cells was gradually inhibited upon increasing GO concentration (panels (b) and (c)). Reprinted with permission from ref 428. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide

Figure 75

Figure 75. Schematic diagram for the transdermal delivery of nano GO–hyaluronic acid conjugates into melanoma skin cancer cells under a NIR laser. Reprinted with permission from ref 435. Copyright 2014 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 76

Figure 76. Pictures showing the effect of photothermal ablation therapy using NIR irradiation on the tumor growth in mice inoculated with B16F1 cells on both dorsal flanks after topical administration of (a) PBS, (b) NGO, and (c) NGO–HA. (d) Day-dependent relative tumor volume. (e) Time-dependent caspase-3 activity in tumor tissues to evaluate the heat-induced apoptosis (***P < 0.0001). Reprinted with permission from ref 435. Copyright 2014 American Chemical Society.

High Resolution Image

Download MS PowerPoint Slide

Figure 77

Figure 77. Schematic diagram for fabrication of biocleavable PDMAEMA–GO sheets by ATRP for gene/drug delivery. Reprinted with permission from ref 438. Copyright 2014 Royal Society of Chemistry.

High Resolution Image

Download MS PowerPoint Slide
References

ARTICLE SECTIONS
Jump To

This article references 446 other publications.
1. 1
  Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A. Electric Field Effect in Atomically Thin Carbon Films Science 2004, 306, 666– 669 DOI: 10.1126/science.1102896
  
  1
  Electric Field Effect in Atomically Thin Carbon Films
  
  Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A.
  
  Science (Washington, DC, United States) (2004), 306 (5696), 666-669CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  The authors describe monocryst. graphitic films, which are a few atoms thick but are nonetheless stable under ambient conditions, metallic, and of remarkably high quality. The films are a two-dimensional semimetal with a tiny overlap between valence and conductance bands, and they exhibit a strong ambipolar elec. field effect such that electrons and holes in concns. up to 1013 per square centimeter and with room-temp. mobilities of ∼10,000 square centimeters per V-second can be induced by applying gate voltage.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2cXos1Kqt70%253D&md5=488da13500bf24e8fc419052dc1a9e84
2. 2
  Balandin, A. A.; Ghosh, S.; Bao, W.; Calizo, I.; Teweldebrhan, D.; Miao, F.; Lau, C. N. Superior Thermal Conductivity of Single-Layer Graphene Nano Lett. 2008, 8, 902– 907 DOI: 10.1021/nl0731872
  
  2
  Superior Thermal Conductivity of Single-Layer Graphene
  
  Balandin, Alexander A.; Ghosh, Suchismita; Bao, Wenzhong; Calizo, Irene; Teweldebrhan, Desalegne; Miao, Feng; Lau, Chun Ning
  
  Nano Letters (2008), 8 (3), 902-907CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  The authors report the measurement of the thermal cond. of a suspended single-layer graphene. The room temp. values of the thermal cond. in the range ∼(4.84 ± 0.44) × 103 to (5.30 ± 0.48) × 103 W/mK were extd. for a single-layer graphene from the dependence of the Raman G peak frequency on the excitation laser power and independently measured G peak temp. coeff. The extremely high value of the thermal cond. suggests that graphene can outperform carbon nanotubes in heat conduction. The superb thermal conduction property of graphene is beneficial for the proposed electronic applications and establishes graphene as an excellent material for thermal management.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXitFegsL4%253D&md5=27fd78ea971fa75db071450655dd7f68
3. 3
  Lee, C.; Wei, X.; Kysar, J. W.; Hone, J. Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene Science 2008, 321, 385– 388 DOI: 10.1126/science.1157996
  
  3
  Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene
  
  Lee, Changgu; Wei, Xiaoding; Kysar, Jeffrey W.; Hone, James
  
  Science (Washington, DC, United States) (2008), 321 (5887), 385-388CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  We measured the elastic properties and intrinsic breaking strength of free-standing monolayer graphene membranes by nanoindentation in an at. force microscope. The force-displacement behavior is interpreted within a framework of nonlinear elastic stress-strain response, and yields second- and third-order elastic stiffnesses of 340 newtons per m (N m-1) and -690 N m-1, resp. The breaking strength is 42 N m-1 and represents the intrinsic strength of a defect-free sheet. These quantities correspond to a Young's modulus of E = 1.0 terapascals, third-order elastic stiffness of D = -2.0 terapascals, and intrinsic strength of σint = 130 gigapascals for bulk graphite. These expts. establish graphene as the strongest material ever measured, and show that atomically perfect nanoscale materials can be mech. tested to deformations well beyond the linear regime.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXosVOrs7k%253D&md5=c85babfb5827a1ce93f7e9673a4c8b86
4. 4
  Schafhaeutl, C. Ueber die Verbindungen des Kohlenstoffes mit Silicium, Eisen und anderen Metallen, welche die verschiedenen Gallungen von Roheisen, Stahl und Schmiedeeisen bilden J. Prakt. Chem. 1840, 21, 129– 157 DOI: 10.1002/prac.18400210117
  
  There is no corresponding record for this reference.
5. 5
  Bernal, J. D. The Structure of Graphite Proc. R. Soc. London, Ser. A 1924, 106, 749– 773 DOI: 10.1098/rspa.1924.0101
  
  There is no corresponding record for this reference.
6. 6
  Wallace, P. R. The Band Theory of Graphite Phys. Rev. 1947, 71, 622– 634 DOI: 10.1103/PhysRev.71.622
  
  6
  The band theory of graphite
  
  Wallace, P. R.
  
  Physical Review (1947), 71 (), 622-34CODEN: PHRVAO; ISSN:0031-899X.
  
  The structure of the electronic energy bands and Brillouin zones for graphite is developed using the tight-binding approximation.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaH2sXitlGlug%253D%253D&md5=c251838b74651969457f8e68a86bf822
7. 7
  Boehm, H. P.; Clauss, A.; Fisher, G. O.; Hofmann, U. Das Adsorptionsverhalten Sehr Dunner Kohlenstoff-Folien Z. Anorg. Allg. Chem. 1962, 316, 119– 127 DOI: 10.1002/zaac.19623160303
  
  7
  The adsorption behavior of very thin carbon films
  
  Boehm, H. P.; Clauss, A.; Fischer, G. O.; Hofmann, U.
  
  Zeitschrift fuer Anorganische und Allgemeine Chemie (1962), 316 (), 119-27CODEN: ZAACAB; ISSN:0044-2313.
  
  Very thin C films were formed by reducing dil. alk. suspensions of graphite oxide or by quickly heating graphite oxide to 300°. The adsorption of PhOH and methylene blue from soln. and of N from the vapor state, and the catalytic efficiency of these firms for the synthesis of HBr were detd. The values of sp. surface of reduced prepns. were greater when detd. by adsorption from soln. than by adsorption from the vapor state or by catalytic efficiency. These differences were attributed to differences in agglomeration during isolation of the films. Films prepd. thermally were porous and less agglomerated, and gave similar surface areas by all the methods of detn. The HBr synthesis is catalyzed chiefly on the basal surfaces of the graphite lattice.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaF38XksF2kuro%253D&md5=ee9c8052a142a00f7e28e0d5f77c95c7
8. 8
  Boehm, H. P.; Clauss, A.; Hofmann, U.; Fisher, G. O. Dunnste Kohlenstoff-Folien Z. Naturforsch., B: J. Chem. Sci. 1962, 17, 150 DOI: 10.1515/znb-1962-0302
  
  There is no corresponding record for this reference.
9. 9
  Hofmann, U.; Frenzel, A. Die Reduktion von Graphitoxyd mit Schwefelwasserstoff Colloid Polym. Sci. 1934, 68, 149– 151 DOI: 10.1007/BF01451376
  
  There is no corresponding record for this reference.
10. 10
  Van Bommel, A. J.; Crombeen, J. E.; Vantooren, A. LEED and Auger-Electron Observation of SiC (0001) Surface Surf. Sci. 1975, 48, 463– 472 DOI: 10.1016/0039-6028(75)90419-7
  
  There is no corresponding record for this reference.
11. 11
  Foster, L. M.; Long, G.; Stumpf, H. C. Production of Graphite Single Crystals by the Thermal Decomposition of Aluminium Carbide Am. Mineral. 1958, 43, 285– 296
  
  There is no corresponding record for this reference.
12. 12
  Land, T. A.; Michely, T.; Behm, R. J.; Hemminger, J. C.; Comsa, G. STM Investigation of Single Layer Graphite Structures Produced on Pt(111) by Hydrocarbon Decomposition Surf. Sci. 1992, 264, 261– 270 DOI: 10.1016/0039-6028(92)90183-7
  
  12
  STM investigation of single layer graphite structures produced on platinum(111) by hydrocarbon decomposition
  
  Land, T. A.; Michely, T.; Behm, R. J.; Hemminger, J. C.; Comsa, G.
  
  Surface Science (1992), 264 (3), 261-70CODEN: SUSCAS; ISSN:0039-6028.
  
  Scanning tunneling microscopy(STM) provides new insight into the nucleation, growth and nature of the graphite layer formed on Pt(111) by hydrocarbon decompn. Annealing an ethylene-covered surface to 800 K results in the formation of small (∼ 20-30 Å in diam.) graphite islands which initially are distributed uniformly over the surface. With further annealing >1000 K, the graphite is obsd. to accumulate, forming a layer at the lower step edges and also forming large, regularly shaped islands on the terraces. It was detd. that hydrocarbon decompn. at elevated temps. results in formation of a single layer of graphite on the Pt surface. It is interesting to note that in the STM images of this single layer of graphite only 3 of the 6 carbon atoms in the graphite lattice are visible. This result cannot be accounted for by the usual explanation given in terms of inequivalent carbons atoms for the bulk graphite surface. Superstructures with periodicities varying up to 22 Å are evident on the graphite areas and are due to a higher order commensurability of the graphite and Pt lattices at different relative rotations.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38XitVWksrs%253D&md5=cf480123184325cb5120209ce648fdab
13. 13
  Forbeaux, I.; Themlin, J. M.; Debever, J. M. Heteroepitaxial Graphite on 6H-SiC(0001): Interface Formation Through Conduction-Band Electronic Structure Phys. Rev. B: Condens. Matter Mater. Phys. 1998, 58, 16396– 16406 DOI: 10.1103/PhysRevB.58.16396
  
  There is no corresponding record for this reference.
14. 14
  Grima, J. N.; Winczewski, S.; Mizzi, L.; Grech, M. C.; Cauchi, R.; Gatt, R.; Attard, D.; Wojciechowski, K. W.; Rybicki, J. Tailoring Graphene to Achieve Negative Poisson’s Ratio Properties Adv. Mater. 2015, 27, 1455– 1459 DOI: 10.1002/adma.201404106
  
  14
  Tailoring Graphene to Achieve Negative Poisson's Ratio Properties
  
  Grima, Joseph N.; Winczewski, Szymon; Mizzi, Luke; Grech, Michael C.; Cauchi, Reuben; Gatt, Ruben; Attard, Daphne; Wojciechowski, Krzysztof W.; Rybicki, Jaroslaw
  
  Advanced Materials (Weinheim, Germany) (2015), 27 (8), 1455-1459CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Mol. dynamics simulations are used to show how the conformation of graphene can be modified through the introduction of defects so as to make it amenable to exhibit a neg. Poisson's ratio (auxeticity). We find that graphene can be turned to an auxetic form simply through the introduction of double vacancy defects of the 5-8-5 type. Results suggest a clear route for turning regular conventional graphene to an auxetic form through the introduction of defects so as to produce one of the thinnest auxetic materials known so far which may be made to achieve tailored anomalous neg. Poisson's ratio properties unattainable in pristine graphene under ambient conditions. The work presented here shows, for the first time, how graphene can be modified to mimic the behavior of a highly and densely wrinkled paper model to the extent that it can exhibit auxetic behavior under ambient conditions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVygsbrM&md5=154924fbf14d7de7e36527e37fd5a77b
15. 15
  Kroto, H. W.; Heath, J. R.; O’Brien, S. C.; Curl, R. F.; Smalley, R. E. C₆₀ – Buckminsterfullerene Nature 1985, 318, 162– 163 DOI: 10.1038/318162a0
  
  15
  C60: buckminsterfullerene
  
  Kroto, H. W.; Heath, J. R.; O'Brien, S. C.; Curl, R. F.; Smalley, R. E.
  
  Nature (London, United Kingdom) (1985), 318 (6042), 162-3CODEN: NATUAS; ISSN:0028-0836.
  
  Laser-induced vaporization of graphite produced a remarkably stable cluster, consisting of 60 C atoms. A truncated icosahedron is suggested, a polygon with 60 vertexes and 32 faces, 12 of which are pentagonal and 20 hexagonal. The C60 mol., which results when a C atom is placed at each vertex of this structure has all the valences satisfied by 2 single bonds and 1 double bond, has many resonance structures and appears to be arom.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL28XotVOktQ%253D%253D&md5=0ca5453a66ee1366682f56b357b40a10
16. 16
  Iijima, S.; Yudasaka, M.; Yamada, R.; Bandow, S.; Suenaga, K.; Kokai, F.; Takahashi, K. Nano-Aggregates of Single-Walled Graphitic Carbon Nano-Horns Chem. Phys. Lett. 1999, 309, 165– 170 DOI: 10.1016/S0009-2614(99)00642-9
  
  16
  Nano-aggregates of single-walled graphitic carbon nano-horns
  
  Iijima, S.; Yudasaka, M.; Yamada, R.; Bandow, S.; Suenaga, K.; Kokai, F.; Takahashi, K.
  
  Chemical Physics Letters (1999), 309 (3,4), 165-170CODEN: CHPLBC; ISSN:0009-2614. (Elsevier Science B.V.)
  
  We have found a new type of carbon particle produced by the CO2 laser ablation of carbon at room temp. without a metal catalyst. The product has a powder form of graphitic particles with a uniform size of about 80 nm. An individual particle is composed of an aggregate of many horn-shaped sheaths of single-walled graphene sheets, which we named carbon nano-horns. The nano-horns can be produced at about 10 g/h.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1MXlt1Wlu7Y%253D&md5=06ca65b6dcc43a47164144b8cb6677ba
17. 17
  Iijima, S. Helical Microtubules of Graphitic Carbon Nature 1991, 354, 56– 58 DOI: 10.1038/354056a0
  
  17
  Helical microtubules of graphitic carbon
  
  Iijima, Sumio
  
  Nature (London, United Kingdom) (1991), 354 (6348), 56-8CODEN: NATUAS; ISSN:0028-0836.
  
  The prepn. of a novel type of finite C structure consisting of needle-like tubes is reported. Produced using an arc-discharge evapn. method similar to that used for fullerenes synthesis, the needles grow at the neg. end of the electrode used for the arc discharge. Electron microscopy reveals that each needle comprises coaxial tubes of graphitic sheets, ranging from 2 to ∼50. On each tube, the C-atom hexagons are arranged in a helical fashion about the needle axis. The helical pitch varies from needle to needle and from tube to tube within a single needle. This helical structure may aid growth. The formation of these needles, ranging from a few to a few tens of nanometers in diam., suggests that engineering of C structures should be possible on scales considerably greater than those relevant to the fullerenes.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38Xmt1Ojtg%253D%253D&md5=ab9fd03bc14a16606749af946bac86bf
18. 18
  Iijima, S.; Ichihashi, T. Single-Shell Carbon Nanotubes of 1-nm Diameter Nature 1993, 363, 603– 605 DOI: 10.1038/363603a0
  
  18
  Single-shell carbon nanotubes of 1-nm diameter
  
  Iijima, Sumio; Ichihashi, Toshinari
  
  Nature (London, United Kingdom) (1993), 363 (6430), 603-5CODEN: NATUAS; ISSN:0028-0836.
  
  The synthesis of abundant single-shell tubes with diams. of ∼1 1 nm is reported. Whereas multi-shell nanotubes are formed on the C cathode, single-shell tubes grow in the gas phase. Electron diffraction from a single tube allows confirmation of the helical arrangement of C hexagons deduced previously for multi-shell tubes.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK3sXltVOrs7o%253D&md5=e6ac48c5bdb705820cb7b6484c0f26c0
19. 19
  Bethune, D. S.; Kiang, C. H.; de Vries, M. S.; Gorman, G.; Savoy, R.; Vazquez, J.; Beyers, R. Cobalt-Catalyzed Growth of Carbon Nanotubes with Single-Atomic-Layerwalls Nature 1993, 363, 605– 607 DOI: 10.1038/363605a0
  
  There is no corresponding record for this reference.
20. 20
  Geim, A. K.; Novoselov, K. S. The Rise of Graphene Nat. Mater. 2007, 6, 183– 191 DOI: 10.1038/nmat1849
  
  20
  The rise of graphene
  
  Geim, A. K.; Novoselov, K. S.
  
  Nature Materials (2007), 6 (3), 183-191CODEN: NMAACR; ISSN:1476-1122. (Nature Publishing Group)
  
  A review. Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here. Whereas one can be certain of the realness of applications only when com. products appear, graphene no longer requires any further proof of its importance in terms of fundamental physics. Owing to its unusual electronic spectrum, graphene has led to the emergence of a new paradigm of 'relativistic' condensed-matter physics, where quantum relativistic phenomena, some of which are unobservable in high-energy physics, can now be mimicked and tested in table-top expts. More generally, graphene represents a conceptually new class of materials that are only one atom thick, and, on this basis, offers new inroads into low-dimensional physics that has never ceased to surprise and continues to provide a fertile ground for applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXit1Khtrg%253D&md5=c2c02ce70a1725e6c559c173156568c5
21. 21
  Bolotin, K. I.; Sikes, K. J.; Jiang, Z.; Klima, M.; Fudenberg, G.; Hone, J.; Kim, P.; Stormer, H. L. Ultrahigh Electron Mobility in Suspended Graphene Solid State Commun. 2008, 146, 351– 355 DOI: 10.1016/j.ssc.2008.02.024
  
  21
  Ultrahigh electron mobility in suspended graphene
  
  Bolotin, K. I.; Sikes, K. J.; Jiang, Z.; Klima, M.; Fudenberg, G.; Hone, J.; Kim, P.; Stormer, H. L.
  
  Solid State Communications (2008), 146 (9-10), 351-355CODEN: SSCOA4; ISSN:0038-1098. (Elsevier Ltd.)
  
  We have achieved mobilities in excess of 200,000 cm2 V -1 s-1 at electron densities of ∼2 × 1011 cm-2 by suspending single layer graphene. Suspension ∼150 nm above a Si/SiO2 gate electrode and elec. contacts to the graphene was achieved by a combination of electron beam lithog. and etching. The specimens were cleaned in situ by employing current-induced heating, directly resulting in a significant improvement of elec. transport. Concomitant with large mobility enhancement, the widths of the characteristic Dirac peaks are reduced by a factor of 10 compared to traditional, nonsuspended devices. This advance should allow for accessing the intrinsic transport properties of graphene.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXls12qu7s%253D&md5=eb2106037936ae4e92f258596283c0c0
22. 22
  Abergel, D. S. L.; Apalkov, V.; Berashevich, J.; Ziegler, K.; Chakraborty, T. Properties of Graphene: a Theoretical Perspective Adv. Phys. 2010, 59, 261– 482 DOI: 10.1080/00018732.2010.487978
  
  22
  Properties of graphene: a theoretical perspective
  
  Abergel, D. S. L.; Apalkov, V.; Berashevich, J.; Ziegler, K.; Chakraborty, Tapash
  
  Advances in Physics (2010), 59 (4), 261-482CODEN: ADPHAH; ISSN:0001-8732. (Taylor & Francis Ltd.)
  
  A review. The electronic properties of graphene, a two-dimensional crystal of carbon atoms, are exceptionally novel. For instance, the low-energy quasiparticles in graphene behave as massless chiral Dirac fermions which has led to the exptl. observation of many interesting effects similar to those predicted in the relativistic regime. Graphene also has immense potential to be a key ingredient of new devices, such as single mol. gas sensors, ballistic transistors and spintronic devices. Bilayer graphene, which consists of two stacked monolayers and where the quasiparticles are massive chiral fermions, has a quadratic low-energy band structure which generates very different scattering properties from those of the monolayer. It also presents the unique property that a tunable band gap can be opened and controlled easily by a top gate. These properties have made bilayer graphene a subject of intense interest. In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the phys. properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theor. models. Recent experminental observations of a metal-insulator transition in hydrogenated graphene is discussed in terms of a self-consistent theory and compared with related numerical simulations. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodn. properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect and optical properties. Confinement of electrons in graphene is non-trivial due to Klein tunnelling. We review various theor. and exptl. studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane-gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXps1CnsrY%253D&md5=7931fdb5e977f07902e61454cd89cb20
23. 23
  Zhang, Z. Z.; Chang, K. Tuning of Energy Levels and Optical Properties of Graphene Quantum Dots Phys. Rev. B: Condens. Matter Mater. Phys. 2008, 77, 235411 DOI: 10.1103/PhysRevB.77.235411
  
  23
  Tuning of energy levels and optical properties of graphene quantum dots
  
  Zhang, Z. Z.; Chang, Kai; Peeters, F. M.
  
  Physical Review B: Condensed Matter and Materials Physics (2008), 77 (23), 235411/1-235411/5CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)
  
  The authors study theor. the magnetic levels and optical properties of zigzag- and armchair-edged hexagonal graphene quantum dots (GQDs) using the tight-binding method. A bound edge state at zero energy appears for the zigzag GQDs in the absence of a magnetic field. The magnetic levels of GQDs exhibit a Hofstadter-butterfly spectrum and approach the Landau levels of 2-dimensional graphene as the magnetic field increases. The optical properties are tuned by the size, the type of the edge, and the external magnetic field.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXot1ylt78%253D&md5=45958acd26d31feae8079506b7bc3fc9
24. 24
  Nakada, K.; Fujita, M.; Dresselhaus, G.; Dresselhaus, M. S. Edge State in Graphene Ribbons: Nanometer Size Effect and Edge Shape Dependence Phys. Rev. B: Condens. Matter Mater. Phys. 1996, 54, 17954– 17961 DOI: 10.1103/PhysRevB.54.17954
  
  24
  Edge state in graphene ribbons: nanometer size effect and edge shape dependence
  
  Nakada, Kyoko; Fujita, Mitsutaka; Dresselhaus, Gene; Dresselhaus, Mildred S.
  
  Physical Review B: Condensed Matter (1996), 54 (24), 17954-17961CODEN: PRBMDO; ISSN:0163-1829. (American Physical Society)
  
  Finite graphite systems having a zigzag edge exhibit a special edge state. The corresponding energy bands are almost flat at the Fermi level and thereby give a sharp peak in the d. of states. The charge d. in the edge state is strongly localized on the zigzag edge sites. No such localized state appears in graphite systems having an armchair edge. By utilizing the graphene ribbon model, we discuss the effect of the system size and edge shape on the special edge state. By varying the width of the graphene ribbons, we find that the nanometer size effect is crucial for detg. the relative importance of the edge state. We also have extended the graphene ribbon to have edges of a general shape, which is defined as a mixt. of zigzag and armchair sites. Examg. the relative importance of the edge state for graphene ribbons with general edges, we find that a non-negligible edge state survives even in graphene ribbons with less developed zigzag edges. We demonstrate that such an edge shape with three or four zigzag sites per sequence is sufficient to show an edge state, when the system size is on a nanometer scale. The special characteristics of the edge state play a large role in detg. the d. of states near the Fermi level for graphite networks on a nanometer scale.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK2sXktlentA%253D%253D&md5=d0b337e10c39d36816b22e63d499ea4e
25. 25
  Kim, W. Y.; Kim, K. S. Prediction of Very Large Values of Magnetoresistance in a Graphene Nanoribbon Device Nat. Nanotechnol. 2008, 3, 408– 412 DOI: 10.1038/nnano.2008.163
  
  25
  Prediction of very large values of magnetoresistance in a graphene nanoribbon device
  
  Kim, Woo Youn; Kim, Kwang S.
  
  Nature Nanotechnology (2008), 3 (7), 408-412CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
  
  Graphene has emerged as a versatile material with outstanding electronic properties that could prove useful in many device applications. Recently, the demonstration of spin injection into graphene and the observation of long spin relaxation times and lengths suggested that graphene could play a role in spintronic' devices that manipulate electron spin rather than charge. In particular zigzag graphene nanoribbons have magnetic (or spin) states at their edges, and these states can be either antiparallel or parallel. Here the authors report the results of 1st-principles simulations that predict that spin-valve devices based on graphene nanoribbons will exhibit magnetoresistance values that are thousands of times higher than previously reported exptl. values. These remarkable values can be linked to the unique symmetry of the band structure in the nanoribbons. Also it is possible to manipulate the band structure of the nanoribbons to generate highly spin-polarized currents. From 1st-principles computer simulations, theorists have predicted that zigzag graphene nanoribbons should display magnetoresistance values that are thousands of times higher than previously reported exptl. values, and also should be able to generate highly spin-polarized currents.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXotFehsLk%253D&md5=fd497e2f843acf889694071215685a91
26. 26
  Nair, R. R.; Blake, P.; Grigorenko, A. N.; Novoselov, K. S.; Booth, T. J.; Stauber, T.; Peres, N. M. R.; Geim, A. K. Fine Structure Constant Defines Visual Transparency of Graphene Science 2008, 320, 1308 DOI: 10.1126/science.1156965
  
  26
  Fine Structure Constant Defines Visual Transparency of Graphene
  
  Nair, R. R.; Blake, P.; Grigorenko, A. N.; Novoselov, K. S.; Booth, T. J.; Stauber, T.; Peres, N. M. R.; Geim, A. K.
  
  Science (Washington, DC, United States) (2008), 320 (5881), 1308CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  There is a small group of phenomena in condensed matter physics that is defined only by the fundamental consts. and does not depend on material parameters. Examples are the resistivity quantum, h/e2 (h is Planck's const. and e the electron charge), that appears in a variety of transport expts. and the magnetic flux quantum, h/e, playing an important role in the physics of supercond. By and large, sophisticated facilities and special measurement conditions are required to observe any of these phenomena. We show that the opacity of suspended graphene is defined solely by the fine structure const., α = e2/ℏc ≈ 1/137 (where c is the speed of light), the parameter that describes coupling between light and relativistic electrons and that is traditionally assocd. with quantum electrodynamics rather than materials science. Despite being only one atom thick, graphene is found to absorb a significant (πα = 2.3%) fraction of incident white light, a consequence of graphene's unique electronic structure.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXmslWgt7k%253D&md5=e99cdff43e2bef193cf9767c6619b4da
27. 27
  Staudenmaier, L. Verfahren zur Darstellung der Graphitsäure Ber. Dtsch. Chem. Ges. 1898, 31, 1481– 1487 DOI: 10.1002/cber.18980310237
  
  27
  Method for the preparation of graphitic acid. [machine translation]
  
  Staudenmaier, L.
  
  Berichte der Deutschen Chemischen Gesellschaft (1898), 31 (), 1481-87CODEN: BDCGAS; ISSN:0365-9496.
  
  [Machine Translation of Descriptors]. The preparation of larger quantities of graphitic acid, C11H4O5 or C11H4O6, was a very lengthy after the known become method by treatment of Ceylon graphite with KClO3 + fuming nitric acid and because of the here frequently occurring explosions of chloric acid incompletely harmless operation; also relatively fastest the method of Moissan (C. r. d. l'Acad. des sciences 119. 976; 121. 538; C. 95. I. 355. II. 1014), leading to the goal, which on the application of anhydrous nitric acid and blown up graphite (C. r. d. l'Acad. des sciences 116. 608; C. 93. I. 852) been based, is not free from these grievances. Author and others represented that the subsequent method, which permits the application of larger quantities graphite, without an explosion of the ClO2 would be to be feared. In a mixture of 1 liter more roughly concentrated sulfuric acid nitric acid of the density 1.4, concentrated cooled down on room temperature, in a flat porcelain dish, with 1/2 l one stirs 25 g blown up graphite and then gradually 450 g KClO3; after repeated churning if the gas evolution left, and colors purely yellow a sample product with KMnO4, then one pours the whole in much water, is served and washed by decanting with water; one heats the green residue brought into a porcelain dish back then on the water bath with a solution of 7 g KMnO4 in 120 ccm with diluted sulfuric acid transferred water up to the disappearance of the red coloration; one gives on that a little H2O2 or hydrochloric acid in addition and leaves untouched still some time; finally those of graphite becomes according to Gottschalk (J. pr. Chem. 95. 321) with nitric acid of the density 1.28, then with alcohol and ether washed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaD28XisFCgtrk%253D&md5=90e7a3cb344a83afe48368a75e8631bb
28. 28
  Hummers, W. S.; Offeman, R. E. Preparation of Graphitic Oxide J. Am. Chem. Soc. 1958, 80, 1339 DOI: 10.1021/ja01539a017
  
  28
  Preparation of graphitic oxide
  
  Hummers, Wm. S., Jr.; Offeman, Richard E.
  
  Journal of the American Chemical Society (1958), 80 (), 1339CODEN: JACSAT; ISSN:0002-7863.
  
  See U.S. 2,798,878 (C.A. 51, 15080a).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaG1cXlt1yjuw%253D%253D&md5=04e888842c5cd001e1ac8daba8de2455
29. 29
  Marcano, D. C.; Kosynkin, D. V.; Berlin, J. M.; Sinitskii, A.; Sun, Z. Z.; Slesarev, A.; Alemany, L. B.; Lu, W.; Tour, J. M. Improved Synthesis of Graphene Oxide ACS Nano 2010, 4, 4806– 4814 DOI: 10.1021/nn1006368
  
  29
  Improved Synthesis of Graphene Oxide
  
  Marcano, Daniela C.; Kosynkin, Dmitry V.; Berlin, Jacob M.; Sinitskii, Alexander; Sun, Zhengzong; Slesarev, Alexander; Alemany, Lawrence B.; Lu, Wei; Tour, James M.
  
  ACS Nano (2010), 4 (8), 4806-4814CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  An improved method for the prepn. of graphene oxide (GO) is described. Currently, Hummers' method (KMnO4, NaNO3, H2SO4) is the most common method used for prepg. graphene oxide. We have found that excluding the NaNO3, increasing the amt. of KMnO4, and performing the reaction in a 9:1 mixt. of H2SO4/H3PO4 improves the efficiency of the oxidn. process. This improved method provides a greater amt. of hydrophilic oxidized graphene material as compared to Hummers' method or Hummers' method with addnl. KMnO4. Moreover, even though the GO produced by our method is more oxidized than that prepd. by Hummers' method, when both are reduced in the same chamber with hydrazine, chem. converted graphene (CCG) produced from this new method is equiv. in its elec. cond. In contrast to Hummers' method, the new method does not generate toxic gas and the temp. is easily controlled. This improved synthesis of GO may be important for large-scale prodn. of GO as well as the construction of devices composed of the subsequent CCG.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXptFOqtrc%253D&md5=2d5c24d0c1af30a5cefdbcfa733e6240
30. 30
  Dryer, D. R.; Park, S.; Bielawski, C. W.; Ruoff, R. S. The Chemistry of Graphene Oxide Chem. Soc. Rev. 2010, 39, 229– 240 DOI: 10.1039/B917103G
  
  There is no corresponding record for this reference.
31. 31
  Hofmann, U.; Konig, E. Untersuchungen über Graphitoxyd Z. Anorg. Allg. Chem. 1937, 234, 311– 336 DOI: 10.1002/zaac.19372340405
  
  31
  Investigations of graphitic oxide
  
  Hofmann, Ulrich; Konig, Ernest
  
  Zeitschrift fuer Anorganische und Allgemeine Chemie (1937), 234 (), 311-36CODEN: ZAACAB; ISSN:0044-2313.
  
  From the agreement in sp. gr. as detd. under xylene and as calcd. from x-ray data, it follows that all the constituents present in appreciable quantity, except ash, are included in the elementary cell. On the edges of the lattice layers are carboxyl groups in which the H is replaceable with other cations, but the old designation of "graphitic acid" is nevertheless considered unsuitable, because active carbons of graphitic structure also possess such genuine acid properties. The name graphitic oxide is justified on the basis that in dry prepns., at least, an overwhelming proportion of the O is linked to the graphite planes. The electrochem. potential of graphitic oxide depends upon the surface oxides found in the external layers. The product obtained by reduction with N2H4.H2O contains up to 50% H2O after drying at 120°. This is because in the reduction a felt of very thin lamellae is produced, in which large quantities of H2O are held. This can be removed gradually by themal decompn. and by pressure. In either case, the thickness of the crystal lamellae grows in the direction of the c-axis. The structural unit of graphitic oxide is believed to be >C.sbd.C< O, which in H2O can be hydrolyzed to >C.sbd.C< OH OH.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaA1cXhsVSitQ%253D%253D&md5=ddf2ae4af1e795567e5d57c0296ac642
32. 32
  Fisher, E. Einfluss der Configuration auf die Wirkung der Enzyme Ber. Dtsch. Chem. Ges. 1894, 27, 2985– 2993 DOI: 10.1002/cber.18940270364
  
  There is no corresponding record for this reference.
33. 33
  Lehn, J. M. Supramolecular Chemistry: Concepts and Perspectives; Wiley: New York, 1995.
  
  There is no corresponding record for this reference.
34. 34
  McMurry, J.; Fayl McCarty, R. C. Chemistry; Pearson Education: New York, 2004.
  
  There is no corresponding record for this reference.
35. 35
  Lide, D. R. CRC Handbook of Chemistry and Physics, 85th ed.; Taylor & Francis: New York, 2004.
  
  There is no corresponding record for this reference.
36. 36
  Atkins, P.; de Paula, J. Physical Chemistry, 7th ed.; W. H. Freeman: New York, 2002.
  
  There is no corresponding record for this reference.
37. 37
  Steed, J. W.; Atwood, J. L. Supramolecular Chemistry, 2nd ed; Wiley: New York, 2013.
  
  There is no corresponding record for this reference.
38. 38
  Skinner, H. A.; Connor, J. A. Metal-Ligand Bond-Energies in Organometallic Compounds Pure Appl. Chem. 1985, 57, 79– 88 DOI: 10.1351/pac198557010079
  
  There is no corresponding record for this reference.
39. 39
  Smithrud, D. B.; Sanford, E. M.; Chao, I.; Ferguson, S. B.; Carcanague, D. R.; Evanseck, J. D.; Houk, K. N.; Diederich, F. Solvent Effects in Molecular Recognition Pure Appl. Chem. 1990, 62, 2227– 2236 DOI: 10.1351/pac199062122227
  
  39
  Solvent effects in molecular recognition
  
  Smithrud, D. B.; Sanford, E. M.; Chao, I.; Ferguson, S. B.; Carcanague, D. R.; Evanseck, J. D.; Houk, K. N.; Diederich, F.
  
  Pure and Applied Chemistry (1990), 62 (12), 2227-36CODEN: PACHAS; ISSN:0033-4545.
  
  Synthetic cyclophane hosts form stable and highly structured inclusion complexes with org. mols. in aq. solns. The soln. geometries of these complexes are detd. in a conformational anal. using Monte Carlo methods. Solvation-desolvation processes are a central factor in detg. the stability of apolar inclusion complexes. The tight binding of small arom. solutes in water in entropically unfavorable and is predominantly enthalpy-driven. A large part of the favorable enthalpy term for strong complexation in water results from its specific contributions. Electron donor-acceptor interactions stabilize complexes between electron-rich cyclophane hosts and electron-deficient arom. substrates; however, they may be masked by specific solvation effects. Computer liq. phase simulations are undertaken to evaluate at a microscopic level the origin of such solvation effects. The progress in the modeling studies is described. Apolar complexation also occurs in org. solvents. Solvents like 2,2,2-trifluoroethanol and ethylene glycol come close to water in their ability to promote apolar complexation. Binding strength decreases from water to polar protic to dipolar aprotic and to apolar solvents. Complexation strength in solvents of all polarity including water and in binary aq. solvent mixts. is predictable according to a linear free energy relationship between the complexation free energy and the empirical solvent polarity parameter ET(30).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK3MXhslamsro%253D&md5=a2f97351891f953b6c0ef14bc9bce378
40. 40
  Southall, N. T.; Dill, K. A.; Haymet, A. D. J. A View of the Hydrophobic Effect J. Phys. Chem. B 2002, 106, 521– 533 DOI: 10.1021/jp015514e
  
  40
  A View of the Hydrophobic Effect
  
  Southall, Noel T.; Dill, Ken A.; Haymet, A. D. J.
  
  Journal of Physical Chemistry B (2002), 106 (3), 521-533CODEN: JPCBFK; ISSN:1089-5647. (American Chemical Society)
  
  A review. Oil and water do not mix. The disaffinity of oil for water, with its unusual temp. dependence, is called the hydrophobic effect. It is important to understand the factors underlying the hydrophobic effect because they appear to play key roles in membrane and micelle formation, protein folding, ligand-protein and protein-protein binding, chromatog. retention, possibly nucleic acid interactions, and the partitioning of drugs, metabolites, and toxins throughout the environment and living systems. Here, we survey exptl. and theor. studies of nonpolar solute partitioning into water. We note that the hydrophobic effect is not just due to "water ordering" and not merely due to small size effects of water. The properties vary substantially with temp. and solute shape. Also, we discuss the limitations of using oil/water partitioning as the basis for some thermodn. models in chem. and biol.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXptFyjurY%253D&md5=f62d28e17b04a77912342f879de77a4b
41. 41
  Hunter, C. A.; Lawson, K. R.; Perkins, C.; Urch, C. J. Aromatic Interactions J. Chem. Soc. Perk. T. 2001, 2, 651– 669 DOI: 10.1039/b008495f
  
  There is no corresponding record for this reference.
42. 42
  Zhang, Z. X.; Huang, H. L.; Yang, X. M.; Zang, L. Tailoring Electronic Properties of Graphene by pi-pi Stacking with Aromatic Molecules J. Phys. Chem. Lett. 2011, 2, 2897– 2905 DOI: 10.1021/jz201273r
  
  42
  Tailoring Electronic Properties of Graphene by π-π Stacking with Aromatic Molecules
  
  Zhang, Zengxing; Huang, Helin; Yang, Xiaomei; Zang, Ling
  
  Journal of Physical Chemistry Letters (2011), 2 (22), 2897-2905CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)
  
  Intrinsic graphene is a semimetal or zero bandgap semiconductor, which hinders its applications for nanoelectronics. To develop high-performance nanodevices with graphene, it is necessary to open the bandgap and precisely control the charge carrier type and d. In this perspective, the authors focus on tailoring the electronic properties of graphene by noncovalent stacking with arom. mols. through π-π interaction. Different types of mols. (functioning as either an electron donor or acceptor when stacked with graphene) as reported in recent literature are presented regarding surface patterning, bandgap engineering, surface doping, as well as applications in nanodevices, particularly the field-effect transistors (FETs). From the current progress along this research line, future issues and challenges are also briefly discussed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtlOks7jP&md5=3c0dc6bb1ab40b465ff8813b41240283
43. 43
  Kozlov, S. M.; Vines, F.; Gorling, A. On the Interaction of Polycyclic Aromatic Compounds with Graphene Carbon 2012, 50, 2482– 2492 DOI: 10.1016/j.carbon.2012.01.070
  
  43
  On the interaction of polycyclic aromatic compounds with graphene
  
  Kozlov, Sergey M.; Vines, Francesc; Goerling, Andreas
  
  Carbon (2012), 50 (7), 2482-2492CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  The adsorption and diffusion of benzene, hexafluorinated benzene, perylene, perylene-3,4,9,10-tetracarboxylic-3,4,9,10-diimide (PTCDI) and perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) on graphene was studied by d. functional means on a generalized gradient approxn. level, including a semi-empirical correction to account for dispersive forces. For all considered mols. the adsorption strength is mainly due to the latter, with the electronic interaction being relatively small and repulsive. As a rule-of-thumb, the strength of the adsorption interaction is 11-13 kJ mol-1 per C atom. The adsorption energies are large enough to avoid desorption at room temp. The estd. diffusion and rotation barriers are remarkably small, thus allowing a rapid diffusion and self-arrangement even at cryogenic temps. Finally, the adsorption of benzene or perylene derivs. may act, depending on the mol. and nature of the substituents, as a source for n- or p-doping, achieving up to 0.2 electrons(holes)/mol. The lowest unoccupied MOs of PTCDI and PTCDA are close in energy to the Dirac point of graphene and induce a conduction gap of ≈210-240 meV in the graphene band structure. Thus, they can be used for graphene band gap engineering and doping by the non-aggressive method of mol. adsorption.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XisFyjtbo%253D&md5=f7fc4d2c05285d4a6f75d76766065504
44. 44
  De Feyter, S.; De Schryver, F. C. Two-Dimensional Supramolecular Self-Assembly Probed by Scanning Tunneling Microscopy Chem. Soc. Rev. 2003, 32, 139– 150 DOI: 10.1039/b206566p
  
  44
  Two-dimensional supramolecular self-assembly probed by scanning tunneling microscopy
  
  De Feyter, Steven; De Schryver, Frans C.
  
  Chemical Society Reviews (2003), 32 (3), 139-150CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)
  
  A review. Supramol. chem. has a very large impact on chem. of current interest and the use of non-covalent but directional forces is appealing for the construction of supramol. architectures. The invention of scanning probe microscopy techniques has opened new doorways to study these concepts on surfaces. This review deals with recent progress in the study of two-dimensional supramol. self-assembly on surfaces probed by STM, with a special emphasis on structure, dynamics, and reactivity of hydrogen bonded systems.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3sXjtFGmt7g%253D&md5=4365d6f57f758462ad5685e951e007ff
45. 45
  Foster, J. S.; Frommer, J. E. Imaging of Liquid-Crystals Using a Tunnelling Microscope Nature 1988, 333, 542– 545 DOI: 10.1038/333542a0
  
  There is no corresponding record for this reference.
46. 46
  Griessl, S.; Lackinger, M.; Edelwirth, M.; Hietschold, M.; Heckl, W. M. Self-Assembled Two-Dimensional Molecular Host-Guest Architectures from Trimesic Acid Single Mol. 2002, 3, 25– 31 DOI: 10.1002/1438-5171(200204)3:1<25::AID-SIMO25>3.0.CO;2-K
  
  46
  Self-assembled two-dimensional molecular host-guest architectures from trimesic acid
  
  Griessl, Stefan; Lackinger, Markus; Edelwirth, Michael; Hietschold, Michael; Heckl, Wolfgang M.
  
  Single Molecules (2002), 3 (1), 25-31CODEN: SGMCF7; ISSN:1438-5163. (Wiley-VCH Verlag Berlin GmbH)
  
  The adsorption of 1,3,5-benzenetricarboxylic (Trimesic) Acid (TMA) to a single crystal graphite surface has been studied under Ultra High Vacuum conditions. This work focuses on inducing a particular self-assembly structure by OMBE (Org. Mol. Beam Epitaxy), characterized by periodic non-dense-packing of the mols. Two coexisting phases could be imaged with sub-mol. resoln. by STM. Induced by directed hydrogen bonding, the org. mols. built in both cases a two-dimensional grid architecture with mol. caves. This two-dimensional host structure can accept single trimesic acid guest mols. in different positions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XjtlWls7Y%253D&md5=14cb94ea07262b7032528748e96c69b9
47. 47
  Lackinger, M.; Griessl, S.; Heckl, W. M.; Hietschold, M. STM and STS of Coronene on HOPG(0001) in UHV – Adsorption of the Smallest Possible Graphite Flakes on Graphite Anal. Bioanal. Chem. 2002, 374, 685– 687 DOI: 10.1007/s00216-002-1458-9
  
  47
  STM and STS of coronene on HOPG(0001) in UHV. Adsorption of the smallest possible graphite flakes on graphite
  
  Lackinger, Markus; Griessl, Stefan; Heckl, Wolfgang M.; Hietschold, Michael
  
  Analytical and Bioanalytical Chemistry (2002), 374 (4), 685-687CODEN: ABCNBP; ISSN:1618-2642. (Springer-Verlag)
  
  The adsorption of the arom. mol. hexabenzobenzene (coronene) on an HOPG(0001) surface was investigated under UHV conditions by means of variable temp. scanning tunneling microscopy (STM) and spectroscopy (STS). Imaging on a mesoscopic scale showed a distribution of coronene islands. These islands are mobile on the surface and can be pinned at step-edges. Zooming in on areas apart from the islands reveals an hexagonal arrangement of coronene mols. in a closed layer. Submol. resolved mols. consist of bright spots with varying intensity. This variation in intensity is explained with the commensurability of the adlayer. STS investigations were performed for various tip-sample distances, adjusted by the tunneling current setpoint. A gap can be seen for every setpoint, but its width is dependent on the setpoint. The gap for the largest tip-sample distance and therefore the smallest tip-sample interaction is compared with the theor. value.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD38XotV2jt7Y%253D&md5=a8837eb01d5927f3b205265ebb2d2be4
48. 48
  Shayeganfar, F.; Rochefort, A. Electronic Properties of Self-Assembled Trimesic Acid Monolayer on Graphene Langmuir 2014, 30, 9707– 9716 DOI: 10.1021/la501619b
  
  48
  Electronic Properties of Self-Assembled Trimesic Acid Monolayer on Graphene
  
  Shayeganfar, F.; Rochefort, A.
  
  Langmuir (2014), 30 (32), 9707-9716CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)
  
  The adsorption of trimesic acid (TMA) on a graphene surface was studied with d. functional theory. By considering the adsorption of a single TMA mol. on different sites on graphene, the authors were able to perform a detailed anal. of the equil. geometry, charge transfer, electronic properties in terms of d. of states and band structure, and finally scanning tunneling microscopy simulations on those simple systems. The results for isolated adsorption were then compared to the behavior of the TMA unit within two different self-assembled monolayers. The authors' results indicate that structural deformations of TMA may significantly contribute to the magnitude of p-doping and band gap opening in graphene. The formation of a hydrogen bonding network within the assembly improves the stability of the adlayer, but its adhesion on graphene is significantly reduced. The magnitude of p-doping in graphene per TMA unit remains nearly const. from the isolated to the assembled systems, but the magnitude of the band gap opening appears to be strongly correlated with the breaking of symmetry of π-states of graphene by the TMA patterning on the surface. The results suggest that polymorphism in self-assembled adlayers could be used to tune and control the electronic properties of graphene.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1eks7jL&md5=5bdafc9ba61c87886a7a018d684fe143
49. 49
  Zhou, Q.; Li, Y.; Li, Q.; Wang, Y.; Yang, Y.; Fang, Y.; Wang, C. Switchable Supramolecular Assemblies on Graphene Nanoscale 2014, 6, 8387– 8391 DOI: 10.1039/c4nr01796j
  
  49
  Switchable supramolecular assemblies on graphene
  
  Zhou, Qiaoyu; Li, Yibao; Li, Qiang; Wang, Yibing; Yang, Yanlian; Fang, Ying; Wang, Chen
  
  Nanoscale (2014), 6 (14), 8387-8391CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  Self-assembly of trimesic acid on single- and few-layer graphene supported by SiO2 substrates has been studied. A scanning tunneling microscope operated under ambient conditions was utilized to image supramol. networks of trimesic acid at liq.-graphene interfaces. Trimesic acid self-assembled into large-scale, highly ordered adlayers on graphene surfaces. Phase transition of the trimesic acid adlayer from a close-packed structure to a porous chicken-wire structure was obsd. by changing from single- to few-layer graphene, which was attributed to the modulation of mol.-graphene interactions by the layer no. of graphene. The guest-induced phase transition of trimesic acid by complexation with coronene on single-layer graphene further confirms that supramol. networks on graphene can be rationally tailored with sub-nanometer resoln. by balancing between intermol. vs. mol.-graphene interactions. The effects of trimesic acid adlayers on the electronic transport properties of graphene transistors were investigated. The adsorption of trimesic acid induced p-doping and defects in the adlayers cause scattering of charge carriers in single-layer graphene.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVKjtrrL&md5=3371cfdf0085e975227bf4617988bc7a
50. 50
  MacLeod, J. M.; Lipton-Duffin, J. A.; Cui, D.; De Feyter, S.; Rosei, F. Substrate Effects in the Supramolecular Assembly of 1,3,5-Benzene Tricarboxylic Acid on Graphite and Graphene Langmuir 2015, 31, 7016– 7024 DOI: 10.1021/la5048886
  
  50
  Substrate Effects in the Supramolecular Assembly of 1,3,5-Benzene Tricarboxylic Acid on Graphite and Graphene
  
  MacLeod, J. M.; Lipton-Duffin, J. A.; Cui, D.; De Feyter, S.; Rosei, F.
  
  Langmuir (2015), 31 (25), 7016-7024CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)
  
  The behavior of small mols. on a surface depends critically on both mol.-substrate and intermol. interactions. We present here a detailed comparative investigation of 1,3,5-benzene tricarboxylic acid (trimesic acid, TMA) on two different surfaces: highly oriented pyrolytic graphite (HOPG) and single-layer graphene (SLG) grown on a polycryst. Cu foil. On the basis of high-resoln. scanning tunnelling microscopy (STM) images, we show that the epitaxy matrix for the hexagonal TMA chicken wire phase is identical on these two surfaces, and, using d. functional theory (DFT) with a non-local van der Waals correlation contribution, we identify the most energetically favorable adsorption geometries. Simulated STM images based on these calcns. suggest that the TMA lattice can stably adsorb on sites other than those identified to maximize binding interactions with the substrate. This is consistent with our net energy calcns. that suggest that intermol. interactions (TMA-TMA dimer bonding) are dominant over TMA-substrate interactions in stabilizing the system. STM images demonstrate the robustness of the TMA films on SLG, where the mol. network extends across the variable topog. of the SLG substrates and remains intact after rinsing and drying the films. These results help to elucidate mol. behavior on SLG and suggest significant similarities between adsorption on HOPG and SLG.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtVSiur0%253D&md5=f8a04bc8b3824c17a8574a9a9fdffcff
51. 51
  Chen, W.; Chen, S.; Qi, D. C.; Gao, X. Y.; Wee, A. T. S. Surface Transfer p-Type Doping of Epitaxial Graphene J. Am. Chem. Soc. 2007, 129, 10418– 10422 DOI: 10.1021/ja071658g
  
  51
  Surface Transfer p-Type Doping of Epitaxial Graphene
  
  Chen, Wei; Chen, Shi; Qi, Dong Chen; Gao, Xing Yu; Wee, Andrew Thye Shen
  
  Journal of the American Chemical Society (2007), 129 (34), 10418-10422CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  Epitaxial graphene thermally grown on 6H-SiC(0001) can be p-type doped via a novel surface transfer doping scheme by modifying the surface with the electron acceptor, tetrafluoro-tetracyanoquinodimethane (F4-TCNQ). Synchrotron-based high-resoln. photoemission spectroscopy reveals that electron transfer from graphene to adsorbed F4-TCNQ is responsible for the p-type doping of graphene. This novel surface transfer doping scheme by surface modification with appropriate mol. acceptors represents a simple and effective method to nondestructively dope epitaxial graphene for future nanoelectronics applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXotlCrur4%253D&md5=a03351dd2efa54aa4e230bde96dbaa4c
52. 52
  Coletti, C.; Riedl, C.; Lee, D. S.; Krauss, B.; Patthey, L.; von Klitzing, K.; Smet, J. H.; Starke, U. Charge Neutrality and Band-Gap Tuning of Epitaxial Graphene on SiC by Molecular Doping Phys. Rev. B: Condens. Matter Mater. Phys. 2010, 81, 235401 DOI: 10.1103/PhysRevB.81.235401
  
  52
  Charge neutrality and band-gap tuning of epitaxial graphene on SiC by molecular doping
  
  Coletti, C.; Riedl, C.; Lee, D. S.; Krauss, B.; Patthey, L.; von Klitzing, K.; Smet, J. H.; Starke, U.
  
  Physical Review B: Condensed Matter and Materials Physics (2010), 81 (23), 235401/1-235401/8CODEN: PRBMDO; ISSN:1098-0121. (American Physical Society)
  
  Epitaxial graphene on SiC(0001) suffers from strong intrinsic n-type doping. The excess neg. charge can be fully compensated by noncovalently functionalizing graphene with the strong electron-acceptor tetrafluorotetracyanoquinodimethane (F4-TCNQ). Charge neutrality can be reached in monolayer graphene as shown in electron-dispersion spectra from angular-resolved photoemission spectroscopy. In bilayer graphene the band-gap that originates from the SiC/graphene interface dipole increases with increasing F4-TCNQ deposition and, as a consequence of the mol. doping, the Fermi level is shifted into the band-gap. The redn. in the charge-carrier d. upon mol. deposition is quantified using electronic Fermi surfaces and Raman spectroscopy. The structural and electronic characteristics of the graphene/F4-TCNQ charge-transfer complex are investigated by XPS and UPS. The doping effect on graphene is preserved in air and is temp. resistant up to 200°. Furthermore, graphene noncovalent functionalization with F4-TCNQ can be implemented not only via evapn. in ultrahigh vacuum but also by wet chem.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXosVynurw%253D&md5=eb2600b204dfb5f478c14873223df6e5
53. 53
  Stradi, D.; Garnica, M.; Diaz, C.; Calleja, F.; Barja, S.; Martin, N.; Alcami, M.; de Parga, A. L. V.; Miranda, R.; Martin, F. Controlling the Spatial Arrangement of Organic Magnetic Anions Adsorbed on Epitaxial Graphene on Ru(0001) Nanoscale 2014, 6, 15271– 15279 DOI: 10.1039/C4NR02917H
  
  There is no corresponding record for this reference.
54. 54
  Huang, H.; Chen, S.; Gao, X.; Chen, W.; Wee, A. T. S. Structural and Electronic Properties of PTCDA Thin Films on Epitaxial Graphene ACS Nano 2009, 3, 3431– 3436 DOI: 10.1021/nn9008615
  
  54
  Structural and electronic properties of PTCDA thin films on epitaxial graphene
  
  Huang, Han; Chen, Shi; Gao, Xingyu; Chen, Wei; Wee, Andrew Thye Shen
  
  ACS Nano (2009), 3 (11), 3431-3436CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  In situ low-temp. scanning tunneling microscopy is used to study the growth of 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) on epitaxial graphene (EG) on 6H-SiC(0001), as well as on HOPG for comparison. PTCDA adopts a layer-by-layer growth mode, with its mol. plane lying flat on both surfaces. The PTCDA films grow continuously over the EG step edges, but not on HOPG. STS performed on single-layer PTCDA on monolayer EG shows a wide band gap larger than 3.3 eV, consistent with pristine PTCDA films. Synchrotron-based high-resoln. photoemission spectroscopy reveals weak charge transfer between PTCDA and EG. This suggests weak electronic coupling between PTCDA and the underlying EG layer.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtlSls7vL&md5=aaecd3399bbb16d4698578d1a0ab6914
55. 55
  Lauffer, P.; Emtsev, K. V.; Graupner, R.; Seyller, T.; Ley, L. Molecular and Electronic Structure of PTCDA on Bilayer Graphene on SiC(0001) Studied with Scanning Tunneling Microscopy Phys. Status Solidi B 2008, 245, 2064– 2067 DOI: 10.1002/pssb.200879615
  
  55
  Molecular and electronic structure of PTCDA on bilayer graphene on SiC(0001) studied with scanning tunneling microscopy
  
  Lauffer, Peter; Emtsev, Konstantin V.; Graupner, Ralf; Seyller, Thomas; Ley, Lothar
  
  Physica Status Solidi B: Basic Solid State Physics (2008), 245 (10), 2064-2067CODEN: PSSBBD; ISSN:0370-1972. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Epitaxial growth of graphene on SiC surfaces by solid state graphitization is a promising route for future development of graphene based electronics. We study the morphol. and mol. scale structure of monolayer films of 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) on bilayer graphene on SiC(0001) by scanning tunneling microscopy (STM). First we discuss how the PTCDA mols. adsorb on bilayer graphene. We specially regard the d. of PTCDA mols. at monolayer coverage. From the comparison with expts. on HOPG (Au(111) and Ag(110) from literature) we infer a non-planar adsorption geometry of PTCDA mols. on bilayer graphene. The electronic structure of the surrounding bilayer graphene substrate is investigated via scanning tunneling spectroscopy (STS) and reveals n-type doping of bilayer graphene during adsorption of PTCDA.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXht12itr3P&md5=a56ecbab414c366796777478530ca6df
56. 56
  Wang, Q. H.; Hersam, M. C. Room-Temperature Molecular-Resolution Characterization of Self-Assembled Organic Monolayers on Epitaxial Graphene Nat. Chem. 2009, 1, 206– 211 DOI: 10.1038/nchem.212
  
  56
  Room-temperature molecular-resolution characterization of self-assembled organic monolayers on epitaxial graphene
  
  Wang, Qing Hua; Hersam, Mark C.
  
  Nature Chemistry (2009), 1 (3), 206-211, s206/1-s206/4CODEN: NCAHBB; ISSN:1755-4330. (Nature Publishing Group)
  
  Graphene, a two-dimensional sheet of carbon atoms, is a promising material for next-generation technol. because of its advantageous electronic properties, such as extremely high carrier mobilities. However, chem. functionalization schemes are needed to integrate graphene with the diverse range of materials required for device applications. The authors report self-assembled monolayers of the mol. semiconductor perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) formed on epitaxial graphene grown on the SiC(0001) surface. The mols. possess long-range order with a herringbone arrangement, as shown by ultra-high vacuum scanning tunneling microscopy at room temp. The mol. ordering is unperturbed by defects in the epitaxial graphene or at. steps in the underlying SiC surface. Scanning tunnelling spectra of the PTCDA monolayer show distinct features that are not obsd. on pristine graphene. The demonstration of robust, uniform org. functionalization of epitaxial graphene presents opportunities for graphene-based mol. electronics and sensors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXmtF2rsL4%253D&md5=1a8685e99fdf539ed2f0a69da9f37a13
57. 57
  Emery, J. D.; Wang, Q. H.; Zarrouati, M.; Fenter, P.; Hersam, M. C.; Bedzyk, M. J. Structural Analysis of PTCDA Monolayers on Epitaxial Graphene with Ultra-High Vacuum Scanning Tunneling Microscopy and High-Resolution X-ray Reflectivity Surf. Sci. 2011, 605, 1685– 1693 DOI: 10.1016/j.susc.2010.11.008
  
  57
  Structural analysis of PTCDA monolayers on epitaxial graphene with ultra-high vacuum scanning tunneling microscopy and high-resolution X-ray reflectivity
  
  Emery, Jonathan D.; Wang, Qing Hua; Zarrouati, Marie; Fenter, Paul; Hersam, Mark C.; Bedzyk, Michael J.
  
  Surface Science (2011), 605 (17-18), 1685-1693CODEN: SUSCAS; ISSN:0039-6028. (Elsevier B.V.)
  
  Epitaxial graphene, grown by thermal decompn. of the SiC (0001) surface, is a promising material for future applications due to its unique and superlative electronic properties. However, the innate chem. passivity of graphene presents challenges for integration with other materials for device applications. Here, we present structural characterization of epitaxial graphene functionalized by the org. semiconductor perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). A combination of ultra-high vacuum scanning tunneling microscopy (STM) and high-resoln. X-ray reflectivity (XRR) is used to ext. lateral and vertical structures of 0, 1, and 2 monolayer (ML) PTCDA on epitaxial graphene. Both Fienup-based phase-retrieval algorithms and model-based least-squares analyses of the XRR data are used to ext. an electron d. profile that is interpreted in terms of a stacking sequence of mol. layers with specific interlayer spacings. Features in the STM and XRR anal. indicate long-range mol. ordering and weak π-π* interactions binding PTCDA mols. to the graphene surface. The high degree of both lateral and vertical ordering of the self-assembled film demonstrates PTCDA functionalization as a viable route for templating graphene for the growth and deposition of addnl. materials required for next-generation electronics and sensors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXpt1Cnsbw%253D&md5=1ef62de746ba8276b7ce53bba68b4645
58. 58
  Pollard, A. J.; Perkins, E. W.; Smith, N. A.; Saywell, A.; Goretzki, G.; Phillips, A. G.; Argent, S. P.; Sachdev, H.; Mueller, F.; Huefner, S. Supramolecular Assemblies Formed on an Epitaxial Graphene Superstructure Angew. Chem., Int. Ed. 2010, 49, 1794– 1799 DOI: 10.1002/anie.200905503
  
  58
  Supramolecular Assemblies Formed on an Epitaxial Graphene Superstructure
  
  Pollard, Andrew J.; Perkins, Edward W.; Smith, Nicholas A.; Saywell, Alex; Goretzki, Gudrun; Phillips, Anna G.; Argent, Stephen P.; Sachdev, Hermann; Mueller, Frank; Huefner, Stefan; Gsell, Stefan; Fischer, Martin; Schreck, Matthias; Osterwalder, Juerg; Greber, Thomas; Berner, Simon; Champness, Neil R.; Beton, Peter H.
  
  Angewandte Chemie, International Edition (2010), 49 (10), 1794-1799, S1794/1-S1794/10CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  We studied the adsorption of perylene tetracarboxylic diimide and related derivs. on a graphene monolayer. It shows that a near-commensurability between their mol. dimensions and a moire-like superstructures leads to the stabilization of extended 1D assemblies.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXivFamsL4%253D&md5=ba79372f3d0d0ea0c700ad041b9e6d45
59. 59
  Karmel, H. J.; Garramone, J. J.; Emery, J. D.; Kewalramani, S.; Bedzyk, M. J.; Hersam, M. C. Self-Assembled Organic Monolayers on Epitaxial Graphene with Enhanced Structural and Thermal Stability Chem. Commun. 2014, 50, 8852– 8855 DOI: 10.1039/C4CC02761B
  
  There is no corresponding record for this reference.
60. 60
  Kozlov, S. M.; Vines, F.; Gorling, A. Bandgap Engineering of Graphene by Physisorbed Adsorbates Adv. Mater. 2011, 23, 2638– 2643 DOI: 10.1002/adma.201100171
  
  60
  Bandgap Engineering of Graphene by Physisorbed Adsorbates
  
  Kozlov, Sergey M.; Vines, Francesc; Goerling, Andreas
  
  Advanced Materials (Weinheim, Germany) (2011), 23 (22-23), 2638-2643CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  We show that a tailor-made bandgap engineering of graphene is possible by physisorbing mols. with a specific electronic structure. By means of calcns. based on d.-functional theory (DFT), we show that suitable adsorbate mols. with the required specific electronic structure exist and that their adsorption has significant and sizeable effects on the graphene band structure. In this work, perylene-3,4,9,10-tetracarboxylic-3,4,9,10-diimide (PTCDI) is used to change the bandgap of graphene. The present findings clearly reveal that the conditions for bandgap opening are well defined, and the size and character of the bandgaps are tunable by varying the adsorbed mol., its coverage, its proximity to the graphene layer and by chem. changing the mol. electronic structure, e.g., by appropriate substituents.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXns1Crsb0%253D&md5=15db7b0e4235082a581f3d05c509906e
61. 61
  Zhang, L. M.; Yu, J. W.; Yang, M. M.; Xie, Q.; Peng, H. L.; Liu, Z. F. Janus Graphene from Asymmetric Two-Dimensional Chemistry Nat. Commun. 2013, 4, 1443 DOI: 10.1038/ncomms2464
  
  61
  Janus graphene from asymmetric two-dimensional chemistry
  
  Zhang Liming; Yu Jingwen; Yang Mingmei; Xie Qin; Peng Hailin; Liu Zhongfan
  
  Nature communications (2013), 4 (), 1443 ISSN:.
  
  Janus materials have distinct surfaces on their opposite faces. Graphene, a two-dimensional giant molecule, provides an excellent candidate to fabricate the thinnest Janus discs and study the asymmetric chemistry of atomic-thick nanomembranes using covalent chemical functionalisation. Here we present the first experimental realisation of nonsymmetrically modified single-layer graphene--Janus graphene--which is fabricated by a two-step surface covalent functionalisation assisted by a poly(methyl methacrylate)-mediated transfer approach. Four types of Janus graphene are produced by co-grafting of halogen and aryl/oxygen-functional groups on each side. Chemical decorations on one side are found to be capable of affecting both chemical reactivity and physical wettability of the opposite side, indicative of communication between the two grafted groups. This novel asymmetric structure provides a platform for theoretical and experimental studies of two-dimensional chemistry and graphene devices with multiple functions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3szlvFCjug%253D%253D&md5=6dcae184c47da7ce2084f83547b36ae5
62. 62
  Hernandez, Y.; Nicolosi, V.; Lotya, M.; Blighe, F. M.; Sun, Z.; De, S.; McGovern, I. T.; Holland, B.; Byrne, M.; Gun’Ko, Y. K. High-Yield Production of Graphene by Liquid-Phase Exfoliation of Graphite Nat. Nanotechnol. 2008, 3, 563– 568 DOI: 10.1038/nnano.2008.215
  
  62
  High-yield production of graphene by liquid-phase exfoliation of graphite
  
  Hernandez, Yenny; Nicolosi, Valeria; Lotya, Mustafa; Blighe, Fiona M.; Sun, Zhenyu; De, Sukanta; McGovern, I. T.; Holland, Brendan; Byrne, Michele; Gun'Ko, Yurii K.; Boland, John J.; Niraj, Peter; Duesberg, Georg; Krishnamurthy, Satheesh; Goodhue, Robbie; Hutchison, John; Scardaci, Vittorio; Ferrari, Andrea C.; Coleman, Jonathan N.
  
  Nature Nanotechnology (2008), 3 (9), 563-568CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
  
  Fully exploiting the properties of graphene will require a method for the mass prodn. of this remarkable material. Two main routes are possible: large-scale growth or large-scale exfoliation. Here, we demonstrate graphene dispersions with concns. up to ∼0.01 mg mL-1, produced by dispersion and exfoliation of graphite in org. solvents such as N-methyl-pyrrolidone. This is possible because the energy required to exfoliate graphene is balanced by the solvent-graphene interaction for solvents whose surface energies match that of graphene. We confirm the presence of individual graphene sheets by Raman spectroscopy, transmission electron microscopy and electron diffraction. Our method results in a monolayer yield of ∼1 wt%, which could potentially be improved to 7-12 wt% with further processing. The absence of defects or oxides is confirmed by x-ray photoelectron, IR, and Raman spectroscopies. We are able to produce semi-transparent conducting films and conducting composites. Soln. processing of graphene opens up a range of potential large-area applications, from device and sensor fabrication to liq.-phase chem. Fully exploiting the properties of graphene will require a method for the mass prodn. of this remarkable material. The dispersion and exfoliation of graphite in org. solvents can produce graphene monolayers with a yield of about 1% by wt. Moreover, these samples are free from defects and oxides, and can be used to produce semi-transparent conducting films and conducting composites.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXhtVOqsLvM&md5=b7159800e921433bc1ff1aead8bbbdbe
63. 63
  Pykal, M.; Safarova, K.; Siskova, K. M.; Jurecka, P.; Bourlinos, A. B.; Zboril, R.; Otyepka, M. Lipid Enhanced Exfoliation for Production of Graphene Nanosheets J. Phys. Chem. C 2013, 117, 11800– 11803 DOI: 10.1021/jp401277g
  
  63
  Lipid Enhanced Exfoliation for Production of Graphene Nanosheets
  
  Pykal, Martin; Safarova, Klara; Machalova Siskova, Karolina; Jurecka, Petr; Bourlinos, Athanasios B.; Zboril, Radek; Otyepka, Michal
  
  Journal of Physical Chemistry C (2013), 117 (22), 11800-11803CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
  
  Liq.-phase exfoliation of graphite is a widely used method to obtain graphene nanosheets, and therefore the development of a simple and efficient exfoliation procedure remains challenging. Here, we present a one-step method of graphene exfoliation in lecithin/chloroform soln. The graphene nanosheets produced by the lecithin-assisted exfoliation method were analyzed by microscopy techniques, including statistical anal. of at. force microscopy (AFM) images and Raman spectroscopy, which both indicate the presence of few-layer graphene nanosheets, including substantial content of three-layer sheets. Mol. dynamics simulations on the time scale of 0.5+ μs suggested that stability of the obtained colloid may originate from formation of lecithin reverse hemimicelles and micelles, which prevents the aggregation of exfoliated graphene flakes by entropic repulsion of the lipid hydrophobic chains.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXnsVKrtLc%253D&md5=78c18fd0dd011a928da456031d675933
64. 64
  Hernandez, Y.; Lotya, M.; Rickard, D.; Bergin, S. D.; Coleman, J. N. Measurement of Multicomponent Solubility Parameters for Graphene Facilitates Solvent Discovery Langmuir 2010, 26, 3208– 3213 DOI: 10.1021/la903188a
  
  64
  Measurement of Multicomponent Solubility Parameters for Graphene Facilitates Solvent Discovery
  
  Hernandez, Yenny; Lotya, Mustafa; Rickard, David; Bergin, Shane D.; Coleman, Jonathan N.
  
  Langmuir (2010), 26 (5), 3208-3213CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)
  
  We have measured the dispersibility of graphene in 40 solvents, with 28 of them previously unreported. We have shown that good solvents for graphene are characterized by a Hildebrand soly. parameter of δT ∼ 23 MPa1/2 and Hansen soly. parameters of δD ∼ 18 MPa1/2, δP ∼ 9.3 MPa1/2, and δH ∼ 7.7 MPa1/2. The dispersibility is smaller for solvents with Hansen parameters further from these values. We have used transmission electron microscopy (TEM) anal. to show that the graphene is well exfoliated in all cases. Even in relatively poor solvents, >63% of obsd. flakes have <5 layers.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtlCkur3F&md5=6f29d613b6521b3085d1f4d7bfbdaf8b
65. 65
  Khan, U.; O’Neill, A.; Lotya, M.; De, S.; Coleman, J. N. High-Concentration Solvent Exfoliation of Graphene Small 2010, 6, 864– 871 DOI: 10.1002/smll.200902066
  
  65
  High-Concentration Solvent Exfoliation of Graphene
  
  Khan, Umar; O'Neill, Arlene; Lotya, Mustafa; De, Sukanta; Coleman, Jonathan N.
  
  Small (2010), 6 (7), 864-871CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A method is demonstrated to prep. graphene dispersions at high concns., up to 1.2 mg mL-1, with yields of up to 4 wt% monolayers. This process relies on low-power sonication for long times, up to 460 h. Transmission electron microscopy shows the sonication to reduce the flake size, with flake dimensions scaling as t-1/2. However, the mean flake length remains above 1 μm for all sonication times studied. Raman spectroscopy shows defects are introduced by the sonication process. However, detailed anal. suggests that predominately edge, rather than basal-plane, defects are introduced. These dispersions are used to prep. high-quality free-standing graphene films. The dispersions can be heavily dild. by water without sedimentation or aggregation. This method facilitates graphene processing for a range of applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXktFGmtLk%253D&md5=e4b650ba820678c7cb904f31a0d3f9d6
66. 66
  O’Neill, A.; Khan, U.; Nirmalraj, P. N.; Boland, J.; Coleman, J. N. Graphene Dispersion and Exfoliation in Low Boiling Point Solvents J. Phys. Chem. C 2011, 115, 5422– 5428 DOI: 10.1021/jp110942e
  
  66
  Graphene Dispersion and Exfoliation in Low Boiling Point Solvents
  
  O'Neill, Arlene; Khan, Umar; Nirmalraj, Peter N.; Boland, John; Coleman, Jonathan N.
  
  Journal of Physical Chemistry C (2011), 115 (13), 5422-5428CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
  
  One of the problems with solvent exfoliation of graphene is that the best solvents tend to have high b.ps. and so are difficult to remove and can present problems for flake deposition and composite formation. Here, we demonstrate the exfoliation of graphene at relatively high concn. in low b.p. solvents such as chloroform and isopropanol. It is possible to achieve concns. of up to 0.5 mg/mL, just under half that which can be achieved with high b.p. solvents such as N-methyl-pyrrolidone. These dispersions consist of graphene flakes of ∼1 μm length and with a thickness of less than 10 layers (≤5 layers for isopropanol). For both solvents, >75% of the graphene remains dispersed indefinitely. Raman spectroscopy shows the flakes to be relatively defect-free. A significant advantage of low b.p. solvents is that they allow individual flakes to be spray cast onto substrates. Deposited densities of >10 flakes with length >1 μm per 10 μm × 10 μm square have been controllably achieved. While some on-substrate aggregation is obsd., this is much less prevalent than when spraying from high b.p. solvents.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXjtVKhtLk%253D&md5=f058605f3a536a5bebdff17d238f4fb3
67. 67
  Coleman, J. N. Liquid Exfoliation of Defect-Free Graphene Acc. Chem. Res. 2013, 46, 14– 22 DOI: 10.1021/ar300009f
  
  67
  Liquid exfoliation of defect-free graphene
  
  Coleman, Jonathan N.
  
  Accounts of Chemical Research (2013), 46 (1), 14-22CODEN: ACHRE4; ISSN:0001-4842. (American Chemical Society)
  
  A review. Due to its unprecedented phys. properties, graphene has generated huge interest over the last 7 years. Graphene is generally fabricated in one of two ways: as very high quality sheets produced in limited quantities by micromech. cleavage or vapor growth or as a rather defective, graphene-like material, graphene oxide, produced in large quantities. However, a growing no. of applications would profit from the availability of a method to produce high-quality graphene in large quantities. This Account describes recent work to develop such a processing route inspired by previous theor. and exptl. studies on the solvent dispersion of carbon nanotubes. That work had shown that nanotubes could be effectively dispersed in solvents whose surface energy matched that of the nanotubes. We describe the application of the same approach to the exfoliation of graphite to give graphene in a range of solvents. When graphite powder is exposed to ultrasonication in the presence of a suitable solvent, the powder fragments into nanosheets, which are stabilized against aggregation by the solvent. The enthalpy of mixing is minimized for solvents with surface energies close to that of graphene (∼68 mJ/m2). The exfoliated nanosheets are free of defects and oxides and can be produced in large quantities. Once solvent exfoliation is possible, the process can be optimized and the nanosheets can be sepd. by size. The use of surfactants can also stabilize exfoliated graphene in water, where the ζ potential of the surfactant-coated graphene nanosheets controls the dispersed concn. Liq. exfoliated graphene can be used for a range of applications: graphene dispersions as optical limiters, films of graphene flakes as transparent conductors or sensors, and exfoliated graphene as a mech. reinforcement for polymer-based composites. Finally, we have extended this process to exfoliate other layered compds. such as BN and MoS2. Such materials will be important in a range of applications from thermoelecs. to battery electrodes. This liq. exfoliation technique can be applied to a wide range of materials and has the potential to be scaled up into an industrial process. We believe the coming decade will see an explosion in the applications involving liq. exfoliated two-dimensional materials.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XktFemur0%253D&md5=d3d0577f3288276a0b9d829cd2fea736
68. 68
  Hughes, J. M.; Ahrene, D.; Coleman, J. N. Generalizing Solubility Parameter Theory to Apply to One- and Two-Dimensional Solutes and to Incorporate Dipolar Interactions J. Appl. Polym. Sci. 2013, 127, 4483– 4491 DOI: 10.1002/app.38051
  
  68
  Generalizing solubility parameter theory to apply to one- and two-dimensional solutes and to incorporate dipolar interactions
  
  Hughes, J. Marguerite; Aherne, Damian; Coleman, Jonathan N.
  
  Journal of Applied Polymer Science (2013), 127 (6), 4483-4491CODEN: JAPNAB; ISSN:0021-8995. (John Wiley & Sons, Inc.)
  
  Hildebrand and Hansen soly. parameters are commonly used to identify suitable solvents for the dispersion or dissoln. of a range of solutes, from small mols. to graphene. This practice is based on a no. of equations, which predict the enthalpy of mixing to be minimized when the soly. parameters of solvent and solute match. However, such equations have only been rigorously derived for mixts. of small mols., which interact only via dispersive forces. Herein, we derive a general expression for the enthalpy of mixing in terms of the dimensionality of the solute, where small mols. are considered zero-dimensional, materials such as polymers or nanotubes are one-dimensional (1D) and platelets such as graphene are two-dimensional (2D). We explicitly include contributions due to dispersive, dipole-dipole, and dipole-induced dipole interactions. We find equations very similar to those of Hildebrand and Hansen so long as the soly. parameters of the solute are defined in a manner which reflects their dimensionality. In addn., the equations for 1D and 2D systems are equiv. to known expressions for the enthalpy of mixing of rods and platelets, resp., as a function of surface energy. This agreement between our expressions and those commonly used shows that the concept of soly. parameters can be rigorously applied to extended solutes such as polymers, nanotubes, and graphene. © 2012 Wiley Periodicals, Inc.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XotFynsLw%253D&md5=65196c5f781e7ea40098c1582863e942
69. 69
  Nicolosi, V.; Chhowalla, M.; Kanatzidis, M. G.; Strano, M. S.; Coleman, J. N. Liquid Exfoliation of Layered Materials Science 2013, 340, 1226419 DOI: 10.1126/science.1226419
  
  There is no corresponding record for this reference.
70. 70
  Wang, S.; Zhang, Y.; Abidi, N.; Cabrales, L. Wettability and Surface Free Energy of Graphene Films Langmuir 2009, 25, 11078– 11081 DOI: 10.1021/la901402f
  
  70
  Wettability and Surface Free Energy of Graphene Films
  
  Wang, Shiren; Zhang, Yue; Abidi, Noureddine; Cabrales, Luis
  
  Langmuir (2009), 25 (18), 11078-11081CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)
  
  Graphene sheets were produced through chem. exfoliation of natural graphite flake and hydrazine conversion. Subsequently, graphene sheets were assembled into a thin film, and microscale liq. droplets were placed onto the film surface for measurement of wettability and contact angle. It is found that a graphene oxide sheet is hydrophilic and a graphene sheet is hydrophobic. Isolated graphene layers seem more difficult to wet in comparison to graphite, and low adhesion work was found in the graphene-liq. interface. Approxn. of solid-liq. interfacial energy with the equation of state theory was applied to det. the graphene surface energy. The results indicate that surface energy of graphene and graphene oxide is 46.7 and 62.1 mJ/m2, resp., while natural graphite flake shows a surface free energy of 54.8 mJ/m2 at room temp. These results will provide valuable guidance for the design and manufg. of graphene-based biomaterials, medical instruments, structural composites, electronics, and renewable energy devices.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXotlahs7w%253D&md5=7e1575d870b2b887aabaf49fbee386ab
71. 71
  Hansen, C. M. Hansen Solubility Parameters: A User’s Handbook, 2nd ed.; CRC Press: New York, 2007.
  
  There is no corresponding record for this reference.
72. 72
  Hansen, C. M. The Three Dimensional Solubility Parameter and Solvent Diffusion Coefficient: Their Importance in Surface Coating Formulation; Danish Technical Press, 1967.
  
  There is no corresponding record for this reference.
73. 73
  Hildebrand, J. H.; Prausnitz, J. M.; Scott, R. L. Regular and Related Solutions: the Solubility of Gases, Liquids, and Solids; van Nostrand Reinhold Co.: New York, 1970.
  
  There is no corresponding record for this reference.
74. 74
  Zhang, Y. H.; Liu, C. J.; Shi, W. Q.; Wang, Z. Q.; Dai, L. M.; Zhang, X. Direct Measurements of the Interaction between Pyrene and Graphite in Aqueous Media by Single Molecule Force Spectroscopy: Understanding the π-π Interactions Langmuir 2007, 23, 7911– 7915 DOI: 10.1021/la700876d
  
  74
  Direct Measurements of the Interaction between Pyrene and Graphite in Aqueous Media by Single Molecule Force Spectroscopy: Understanding the π-π Interactions
  
  Zhang, Yiheng; Liu, Chuanjun; Shi, Weiqing; Wang, Zhiqiang; Dai, Liming; Zhang, Xi
  
  Langmuir (2007), 23 (15), 7911-7915CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)
  
  Pyrene derivs. can absorb onto the surface of carbon nanotubes and graphite particles through π-π interactions to functionalize these inorg. building blocks with org. surface moieties. Using single mol. force spectroscopy, we have demonstrated the first direct measurement of the interaction between pyrene and a graphite surface. In particular, we have connected a pyrene mol. onto an AFM tip via a flexible poly(ethylene glycol) (PEG) chain to ensure the formation of a mol. bridge. The π-π interaction between pyrene and graphite is thus indicated to be ∼55 pN with no hysteresis between the desorption and adhesion forces.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXmvVOkt7Y%253D&md5=44259aa8612e917e70e5c5d7a1870fdc
75. 75
  Manohar, S.; Mantz, A. R.; Bancroft, K. E.; Hui, C. Y.; Jagota, A.; Vezenov, D. V. Peeling Single-Stranded DNA from Graphite Surface to Determine Oligonucleotide Binding Energy by Force Spectroscopy Nano Lett. 2008, 8, 4365– 4372 DOI: 10.1021/nl8022143
  
  75
  Peeling Single-Stranded DNA from Graphite Surface to Determine Oligonucleotide Binding Energy by Force Spectroscopy
  
  Manohar, Suresh; Mantz, Amber R.; Bancroft, Kevin E.; Hui, Chung-Yuen; Jagota, Anand; Vezenov, Dmitri V.
  
  Nano Letters (2008), 8 (12), 4365-4372CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  The authors measured the force required to peel single-stranded DNA mols. from single-crystal graphite using chem. force microscopy. Force traces during retraction of a tip chem. modified with oligonucleotides displayed characteristic plateaus with abrupt force jumps, which the authors interpreted as a steady state peeling process punctuated by complete detachment of one or more mols. The authors were able to differentiate between bases in pyrimidine homopolymers; peeling forces were 85.3±4.7 pN for polythymine and 60.8±5.5 pN for polycytosine, substantially independent of salt concn. and the rate of detachment. The authors developed a model for peeling a freely jointed chain from the graphite surface and estd. the av. binding energy per monomer to be 11.5±0.6 kBT and 8.3±0.7 kBT in the cases of thymine and cytosine nucleotides, resp. The equil. free-energy profile simulated using mol. dynamics had a potential well of 18.9 kBT for thymidine, showing that nonelectrostatic interactions dominate the binding. The discrepancy between the expt. and theory indicates that not all bases are adsorbed on the surface or that there is a population of conformations in which they adsorb. Force spectroscopy using oligonucleotides covalently linked to AFM tips provides a flexible and unambiguous means to quantify the strength of interactions between DNA and a no. of substrates, potentially including nanomaterials such as carbon nanotubes.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXhtlCqur7K&md5=75cda9909f155ed374703d821d85967f
76. 76
  Georgakilas, V.; Otyepka, M.; Bourlinos, A. B.; Chandra, V.; Kim, N.; Kemp, K. C.; Hobza, P.; Zboril, R.; Kim, K. S. Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications Chem. Rev. 2012, 112, 6156– 6214 DOI: 10.1021/cr3000412
  
  76
  Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications
  
  Georgakilas, Vasilios; Otyepka, Michal; Bourlinos, Athanasios B.; Chandra, Vimlesh; Kim, Namdong; Kemp, K. Christian; Hobza, Pavel; Zboril, Radek; Kim, Kwang S.
  
  Chemical Reviews (Washington, DC, United States) (2012), 112 (11), 6156-6214CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)
  
  This comprehensive review covers all modes and methods of graphene functionalization including their classification. The complementary discussions of both exptl. and theor. aspects of graphene functionalization and interaction is presented. The functionalization modes related to chem. of graphene derivs. (graphene oxide, graphane, fluorographene) represent a significant part of the review, which thus considerably exceeds the chem. of pristine graphene. Both covalent functionalization based on binding of org. functionalities like free radicals and dienophiles on pristine graphene and attachment through the chem. of oxygen groups of graphene oxide are comprehensively discussed. The covalent attachments of hydrogen and halogens and, generally, the chem. of graphane and fluorographene are described. Noncovalent functionalization and interactions, which do not disrupt the extended p-conjugation on the graphene surface unlike covalent functionalization, are discussed. The theory of graphene-ligand non-covalent interactions is presented, while various interaction modes (p interactions) are analyzed from both theor. and exptl. viewpoints. The methods of deposition of various nanostructures on graphene are discussed, including a great variety of nanoparticles like noble metals, metal oxides, quantum dots, polymers, and others. The superior properties and applicability of these graphene-nanoparticle composites are extensively analyzed. The specific methods of graphene doping to control the type and concn. of charged carriers are summarized. Selected applications of functionalized graphene, including doped graphene electronic devices, magnetic bilayer intercalates, electronic/spintronic devices, and DNA sequencing devices, green chem., and bio-imaging, are discussed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhtl2mu7fL&md5=0069788307b69d0290cf24036a9015c4
77. 77
  Lee, E. C.; Kim, D.; Jurečka, P.; Tarakeshwar, P.; Hobza, P.; Kim, K. S. Understanding of Assembly Phenomena by Aromatic-Aromatic Interactions: Benzene Dimer and the Substituted Systems J. Phys. Chem. A 2007, 111, 3446– 3457 DOI: 10.1021/jp068635t
  
  77
  Understanding of Assembly Phenomena by Aromatic-Aromatic Interactions: Benzene Dimer and the Substituted Systems
  
  Lee, Eun Cheol; Kim, Dongwook; Jurecka, Petr; Tarakeshwar, P.; Hobza, Pavel; Kim, Kwang S.
  
  Journal of Physical Chemistry A (2007), 111 (18), 3446-3457CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)
  
  Interactions involving arom. rings are important in mol./biomol. assembly and engineering. As a consequence, there have been a no. of investigations on dimers involving benzene or other substituted π systems. In this Feature Article, we examine the relevance of the magnitudes of their attractive and repulsive interaction energy components in governing the geometries of several π-π systems. The geometries and the assocd. binding energies were evaluated at the complete basis set (CBS) limit of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using a least biased scheme for the given data set. The results for the benzene dimer indicate that the floppy T-shaped structure (center-to-center distance: 4.96 Å, with an axial benzene off-centered above the facial benzene) is isoenergetic in zero-point-energy (ZPE) cor. binding energy (D0) to the displaced-stacked structure (vertical interplanar distance: 3.54 Å). However, the T-shaped structure is likely to be slightly more stable (D0 ≈ 2.4-2.5 kcal/mol) if quadruple excitations are included in the coupled cluster calcns. The presence of substituents on the arom. ring, irresp. of their electron withdrawing or donating nature, leads to an increase in the binding energy, and the displaced-stacked conformations are more stabilized than the T-shaped conformers. This explains the wide prevalence of displaced stacked structures in org. crystals. Despite that the dispersion energy is dominating, the substituent as well as the conformational effects are correlated to the electrostatic interaction. This electrostatic origin implies that the substituent effect would be reduced in polar soln., but important in apolar media, in particular, for assembling processes.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXktFegt78%253D&md5=55e2063e88f9f028c005fc78a57f00c0
78. 78
  Su, Q.; Pang, S.; Alijani, V.; Li, C.; Feng, X.; Muellen, K. Composites of Graphene with Large Aromatic Molecules Adv. Mater. 2009, 21, 3191– 3195 DOI: 10.1002/adma.200803808
  
  78
  Composites of Graphene with Large Aromatic Molecules
  
  Su, Qi; Pang, Shuping; Alijani, Vajiheh; Li, Chen; Feng, Xinliang; Muellen, Klaus
  
  Advanced Materials (Weinheim, Germany) (2009), 21 (31), 3191-3195CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  We have demonstrated an unprecedented approach to noncovalently functionalized graphene with large arom. donor and acceptor mols., resulting in a novel combination of graphene and nanographene building blocks. By this means, one can effectively stabilize the aq. dispersion of graphene sheets and hence yield monolayer and double-layer graphene sheets on substrates in large quantities. Our results further disclose that the different electronic characteristics of large arom. donor and acceptor mols. enable a rational modification of both the electronic structure and cond. of graphene sheets. Remarkably, the further thermal redn. of graphene sheets accompanied by addnl. thermal reaction of nanographene units leads to a dramatic increase of the cond. As a consequence, the power efficiency is greatly improved using graphene composite film as electrodes in heterojunction solar cells.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtVCgurvP&md5=00b0f407e5a4f72754607c2816fd3328
79. 79
  Zhang, X. F.; Liu, S. P.; Shao, X. N. Noncovalent Binding of Xanthene and Phthalocyanine Dyes with Graphene Sheets: The Effect of the Molecular Structure Revealed by a Photophysical Study Spectrochim. Acta, Part A 2013, 113, 92– 99 DOI: 10.1016/j.saa.2013.04.066
  
  79
  Noncovalent binding of xanthene and phthalocyanine dyes with graphene sheets: The effect of the molecular structure revealed by a photophysical study
  
  Zhang, Xian-Fu; Liu, Su-Ping; Shao, Xiao-Na
  
  Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy (2013), 113 (), 92-99CODEN: SAMCAS; ISSN:1386-1425. (Elsevier B.V.)
  
  The fluorescence and absorption properties of several xanthene and phthalocyanine dyes were measured in the presence and absence of chem. derived graphene (CDG) sheets. The interaction of pyronine Y (PYY) with graphene sheets was compared with that of rhodamine 6G (R6G) to reveal the effect of the mol. structure. Although the presence of the perpendicular benzene moiety in a R6G or phthalocyanine mol. does cause the difficulty for forming dye-CDG complex and make CDG less efficient in quenching the fluorescence intensity and shortening the fluorescence lifetime, it does not affect the band position of charge transfer absorption, suggesting that no mol. shape change occurred in a dye mol. caused by the interaction with CDG sheets. The spectroscopic and thermodn. data indicated that the dye-CDG binding is of charge transfer nature, while the dynamic fluorescence quenching is due to photoinduced energy and electron transfer.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtVKnu7zE&md5=1f615c7d709ce4826ae06d024659b5d4
80. 80
  Yang, X.; Li, J.; Wen, T.; Ren, X.; Huang, Y.; Wang, X. Adsorption of Naphthalene and Its Derivatives on Magnetic Graphene Composites and the Mechanism Investigation Colloids Surf., A 2013, 422, 118– 125 DOI: 10.1016/j.colsurfa.2012.11.063
  
  80
  Adsorption of naphthalene and its derivatives on magnetic graphene composites and the mechanism investigation
  
  Yang, Xin; Li, Jiaxing; Wen, Tao; Ren, Xuemei; Huang, Yongshun; Wang, Xiangke
  
  Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2013), 422 (), 118-125CODEN: CPEAEH; ISSN:0927-7757. (Elsevier B.V.)
  
  Reduced graphene oxide/iron oxide (GO/FeOFe2O3) composites were prepd. as super adsorbent to adsorb 1-naphthylamine, 1-naphthol and naphthalene with different polaritiy. The adsorption capacity was found in the order of naphthalene < 1-naphthol < 1-naphthylamine. Electron-donor-acceptor (EDA) interaction was proposed to be the primary mechanism for the adsorption of arom. compds., and the adsorption capacity increased with increasing dipole moment. Compared with multi-walled carbon nanotubes/iron oxide (MWCNTs/FeOFe2O3), we found the morphol. of adsorbents played an important role in the adsorption for these arom. compds. Thermodn. expts. further indicated that the adsorption processes were endothermic and spontaneous.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXktFalsbo%253D&md5=763ad52c0b8b5a4f8cd9da45f1efda38
81. 81
  Zhang, X. F.; Shao, X. Binding Ability of Different Carbon Nano-Materials with Aromatic Phthalocyanine Molecules: Comparison between Graphene and Graphene Oxide J. Photochem. Photobiol., A 2014, 278, 69– 74 DOI: 10.1016/j.jphotochem.2014.01.001
  
  81
  π-π binding ability of different carbon nano-materials with aromatic phthalocyanine molecules: Comparison between graphene, graphene oxide and carbon nanotubes
  
  Zhang, Xian-Fu; Shao, Xiaona
  
  Journal of Photochemistry and Photobiology, A: Chemistry (2014), 278 (), 69-74CODEN: JPPCEJ; ISSN:1010-6030. (Elsevier B.V.)
  
  The π-π stacking ability of graphene sheets (GS), graphene oxide (GO), and single walled carbon nanotubes (SWCNT) with phthalocyanine (Pc) mols. was studied by the UV-vis absorption, steady state and time-resolved fluorescence spectra. Absorption spectra revealed that strong π-π binding with the Pc ground state (S0) occurred for GS and GO but not for SWCNT, the binding ability is GS » GO » SWCNT. However, when a Pc mol. is photoexcited, fluorescence study shows that the π-π interaction capability is changed to GS » SWCNT » GO. Although SWCNT exhibits low ability to bind Pc S0 state, it strongly interacts with Pc S1 state. The data anal. shows that the dynamic quenching for the nanoscaled carbon quenchers still obeys linear Stern-Volmer relationship, but the static quenching is not linear. An exponential expression is needed to fit the data for GS and SWCNT, which indicates that an effective quenching sphere model is valid for the nanoscaled fluorescence quenchers.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitlSnu74%253D&md5=4f29aaf89cd222872218a33069a65da5
82. 82
  Wang, J.; Chen, Z.; Chen, B. Adsorption of Polycyclic Aromatic Hydrocarbons by Graphene and Graphene Oxide Nanosheets Environ. Sci. Technol. 2014, 48, 4817– 4825 DOI: 10.1021/es405227u
  
  82
  Adsorption of Polycyclic Aromatic Hydrocarbons by Graphene and Graphene Oxide Nanosheets
  
  Wang, Jun; Chen, Zaiming; Chen, Baoliang
  
  Environmental Science & Technology (2014), 48 (9), 4817-4825CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
  
  The adsorption of naphthalene, phenanthrene, and pyrene onto graphene (GNS) and graphene oxide (GO) nanosheets was investigated to probe the potential adsorptive sites and mol. mechanisms. The microstructure and morphol. of GNS and GO were characterized by elemental anal., XPS, FTIR, Raman, SEM, and TEM. Graphene displayed high affinity to the polycyclic arom. hydrocarbons (PAHs), whereas GO adsorption was significantly reduced after oxygen-contg. groups were attached to GNS surfaces. An unexpected peak was found in the curve of adsorption coeffs. (Kd) with the PAH equil. concns. The hydrophobic properties and mol. sizes of the PAHs affected the adsorption of G and GO. The high affinities of the PAHs to GNS are dominated by π-π interactions to the flat surface and the sieving effect of the powerful groove regions formed by wrinkles on GNS surfaces. In contrast, the adsorptive sites of GO changed to the carboxyl groups attaching to the edges of GO because the groove regions disappeared and the polar nanosheet surfaces limited the π-π interactions. The TEM and SEM images initially revealed that after loading with PAH, the conformation and aggregation of GNS and GO nanosheets dramatically changed, which explained the observations that the potential adsorption sites of GNS and GO were unusually altered during the adsorption process.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXltFGltb0%253D&md5=abd6e1601312a6c861b1799cf4facbcb
83. 83
  Chen, I. W. P.; Huang, C. Y.; Jhou, S. H. S.; Zhang, Y. W. Exfoliation and Performance Properties of Non-Oxidized Graphene in Water Sci. Rep. 2014, 4, 3928 DOI: 10.1038/srep03928
  
  83
  Exfoliation and Performance Properties of Non-Oxidized Graphene in Water
  
  Chen, I.-Wen Peter; Huang, Chun-Yuan; Saint Jhou, Sheng-Hong; Zhang, Yu-Wei
  
  Scientific Reports (2014), 4 (), 3928/1-3928/6CODEN: SRCEC3; ISSN:2045-2322. (Nature Publishing Group)
  
  Single-layered graphene has unique electronic, chem., and electromech. properties. Recently, graphite exfoliation in N-methylpyrrolidone and molten salt has been demonstrated to generate monolayer exfoliated graphene sheets (EGS). However, these solvents are either high-priced or require special care and have high b.ps. and viscosities, making it difficult to deposit the dispersed graphene onto substrates. Here we show a universal principle for the exfoliation of graphite in water to single-layered and several-layered graphene sheets via the direct exfoliation of highly oriented pyrolytic graphite (HOPG) using pyridinium tribromide (Py+Br3-). Elec. cond. >5100 S/cm was obsd. for filtered graphene paper, and the EGS exhibited superior performance as a hole transport layer compared to the conventional material N,N-di(naphthalene-1-yl)-N,N-diphenylbenzidine at low voltage. The overall results demonstrate that this method is a scalable process for the prepn. of highly conductive graphene for use in the com. manuf. of high-performance electronic devices.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXlsVCjur0%253D&md5=4590fbd62e9af77391cdc2b2318e24eb
84. 84
  Bourlinos, A. B.; Georgakilas, V.; Zboril, R.; Steriotis, T. A.; Stubos, A. K. Liquid-Phase Exfoliation of Graphite towards Solubilized Graphenes Small 2009, 5, 1841– 1845 DOI: 10.1002/smll.200900242
  
  84
  Liquid-Phase Exfoliation of Graphite Towards Solubilized Graphenes
  
  Bourlinos, Athanasios B.; Georgakilas, Vasilios; Zboril, Radek; Steriotis, Theodore A.; Stubos, Athanasios K.
  
  Small (2009), 5 (16), 1841-1845CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  This paper describes a neoteric set of solvents for the liq.-phase exfoliation of graphite towards solubilized graphenes. The proposed solvents belong to a peculiar class of perfluorinated arom. mols. and include hexafluorobenzene, octafluorotoluene, pentafluorobenzonitrile, and pentafluoropyridine. Complementary to these liqs., blank expts. with the related hydrocarbon analogs unexpectedly led to the notable case of pyridine. Along with these solvents, an assortment of other suitable dispersing media is cited in parallel. The conversion of the as-derived single sheets into metal-graphene hybrids is also presented.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXps1yku74%253D&md5=525ab89601b8b5fedffa1f97f672eee0
85. 85
  Kim, J.; Song, S. H.; Im, H. G.; Yoon, G.; Lee, D.; Choi, C.; Kim, J.; Bae, B. S.; Kang, K.; Jeon, S. Moisture Barrier Composites Made of Non-Oxidized Graphene Flakes Small 2015, 11, 3124– 3129 DOI: 10.1002/smll.201403647
  
  85
  Moisture Barrier Composites Made of Non-Oxidized Graphene Flakes
  
  Kim, Jungmo; Song, Sung Ho; Im, Hyeon-Gyun; Yoon, Gabin; Lee, Dongju; Choi, Chanyong; Kim, Jin; Bae, Byeong-Soo; Kang, Kisuk; Jeon, Seokwoo
  
  Small (2015), 11 (26), 3124-3129CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  We demonstrate improved moisture barrier property of polyethylene (PE) composite, approaching the theor. value, by incorporating low-defect-content non-oxidized graphene flakes (NOGFs). The fabrication of NOGFs in micrometer scale (>1 μm) and their functionalization were simultaneously achieved by introducing solvothermal intercalation of an org. solvent, quinoline. Partial intercalation of quinoline mols. promoted exfoliation efficiency by lowering the interlayer binding energy of graphite by 30 meV, calcd. from d. functional theory (DFT)-based simulations. Compared to NOGFs produced solely from sonication, the produced NOGFs had increased av. size while exhibiting high crystallinity and extremely low oxidn., comparable to that of source graphite. Moreover, the conjugated nature of quinoline resulted in stable non-covalent functionalization of the NOGFs whose zeta potential is -20 mV, large enough for uniform dispersion with increased hydrophobicity in the matrix polymer. The low-defect NOGFs with minimal oxidn. and high hydrophobicity are ideal as nanofillers for moisture barrier composites. The water vapor transmission rate (WVTR) of polyethylene (PE)-NOGF composite film with a 1 wt% loading compared to the pristine PE film and the PE-GO composite film of similar loading showed a redn. of the WVTR of 58% and 37.5%, resp. The measured WVTR value of PE-NOGF was 1.2 x 10-1 g.m-2.day-1, which is an order of magnitude lower than the previously reported value for polymer-graphene composites.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXkvF2ktbo%253D&md5=b42538390e3f76d134c67f3cef47ce4b
86. 86
  Lee, D. W.; Kim, T.; Lee, M. An Amphiphilic Pyrene Sheet for Selective Functionalization of Graphene Chem. Commun. 2011, 47, 8259– 8261 DOI: 10.1039/c1cc12868j
  
  86
  An amphiphilic pyrene sheet for selective functionalization of graphene
  
  Lee, Dong-Woo; Kim, Taehoon; Lee, Myongsoo
  
  Chemical Communications (Cambridge, United Kingdom) (2011), 47 (29), 8259-8261CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)
  
  It was demonstrated that the arom. amphiphile consisting of a hydrophilic dendron and an arom. segment with a planar conformation can selectively exfoliate graphite powder into single- and double-layer graphene sheets in aq. soln. through hydrophilic functionalization of graphene surfaces.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXoslajt7Y%253D&md5=5cd156fef0aca70ab39d7b693b9e96cd
87. 87
  Yang, H.; Hernandez, Y.; Schlierf, A.; Felten, A.; Eckmann, A.; Johal, S.; Louette, P.; Pireaux, J. J.; Feng, X.; Muellen, K. A Simple Method for Graphene Production Based on Exfoliation of Graphite in Water Using 1-Pyrenesulfonic Acid Sodium Salt Carbon 2013, 53, 357– 365 DOI: 10.1016/j.carbon.2012.11.022
  
  87
  A simple method for graphene production based on exfoliation of graphite in water using 1-pyrenesulfonic acid sodium salt
  
  Yang, H.; Hernandez, Y.; Schlierf, A.; Felten, A.; Eckmann, A.; Johal, S.; Louette, P.; Pireaux, J.-J.; Feng, X.; Mullen, K.; Palermo, V.; Casiraghi, C.
  
  Carbon (2013), 53 (), 357-365CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  A chem. approach was used based on supramol. and non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py-1SO3) to obtain a stable dispersion of graphene by only water as solvent. The material was characterized by a combination of spectroscopic and microscopic techniques. In particular, an extensive Raman anal. shows that ≈70% have few-graphene layers (<7). The exfoliation efficiency strongly depends on the no. of functional groups by comparing suspensions obtained by Py-1SO3 and 1,3,6,8-pyrenetetrasulfonic acid (Py-4SO3). A strong decrease in the exfoliation yield was obsd. by pyrene with 4 sulfonic groups (Py-4SO3), as compared to one sulfonic group (Py-1SO3). Being completely water-based, these suspensions can be used as inks for printable tattoo-based electrochem. sensors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhslOjtbjI&md5=f786c844804953f06f086871bf31b6e2
88. 88
  Jang, J. H.; Rangappa, D.; Kwon, Y. U.; Honma, I. Direct Preparation of 1-PSA Modified Graphene Nanosheets by Supercritical Fluidic Exfoliation and Its Electrochemical Properties J. Mater. Chem. 2011, 21, 3462– 3466 DOI: 10.1039/C0JM02472D
  
  There is no corresponding record for this reference.
89. 89
  An, X. H.; Simmons, T. J.; Shah, R.; Wolfe, C.; Lewis, K. M.; Washington, M.; Nayak, S. K.; Talapatra, S.; Kar, S. Stable Aqueous Dispersions of Noncovalently Functionalized Graphene from Graphite and their Multifunctional High-Performance Applications Nano Lett. 2010, 10, 4295– 4301 DOI: 10.1021/nl903557p
  
  89
  Stable Aqueous Dispersions of Noncovalently Functionalized Graphene from Graphite and their Multifunctional High-Performance Applications
  
  An, Xiaohong; Simmons, Trevor; Shah, Rakesh; Wolfe, Christopher; Lewis, Kim M.; Washington, Morris; Nayak, Saroj K.; Talapatra, Saikat; Kar, Swastik
  
  Nano Letters (2010), 10 (11), 4295-4301CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  We present a scalable and facile technique for noncovalent functionalization of graphene with 1-pyrenecarboxylic acid that exfoliates single-, few-, and multilayered graphene flakes into stable aq. dispersions. The exfoliation mechanism is established using stringent control expts. and detailed characterization steps. Using the exfoliated graphene, we demonstrate highly sensitive and selective conductometric sensors (whose resistance rapidly changes >10,000% in satd. ethanol vapor), and ultracapacitors with extremely high specific capacitance (∼120 F/g), power d. (∼105 kW/kg), and energy d. (∼9.2 Wh/kg).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXns1Wru7w%253D&md5=140b93a45ebef632706a8c271c2f65c7
90. 90
  Dong, X. C.; Shi, Y. M.; Zhao, Y.; Chen, D. M.; Ye, J.; Yao, Y. G.; Gao, F.; Ni, Z. H.; Yu, T.; Shen, Z. X. Symmetry Breaking of Graphene Monolayers by Molecular Decoration Phys. Rev. Lett. 2009, 102, 135501 DOI: 10.1103/PhysRevLett.102.135501
  
  90
  Symmetry Breaking of Graphene Monolayers by Molecular Decoration
  
  Dong, Xiaochen; Shi, Yumeng; Zhao, Yang; Chen, Dongmeng; Ye, Jun; Yao, Yugui; Gao, Fang; Ni, Zhenhua; Yu, Ting; Shen, Zexiang; Huang, Yinxi; Chen, Peng; Li, Lain-Jong
  
  Physical Review Letters (2009), 102 (13), 135501/1-135501/4CODEN: PRLTAO; ISSN:0031-9007. (American Physical Society)
  
  Arom. mols. can effectively exfoliate graphite into graphene monolayers, and the resulting graphene monolayers sandwiched by the arom. mols. exhibit a pronounced Raman G-band splitting, similar to that obsd. in single-walled carbon nanotubes. Raman measurements and calcns. based on the force-const. model demonstrate that the absorbed arom. mols. are responsible for the G-band splitting by removing the energy degeneracy of in-plane longitudinal and transverse optical phonons at the Γ point.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXktV2qtLg%253D&md5=6c35ec693586296313caa33bb30b4b6d
91. 91
  Zhang, M.; Parajuli, R. R.; Mastrogiovanni, D.; Dai, B.; Lo, P.; Cheung, W.; Brukh, R.; Chiu, P. L.; Zhou, T.; Liu, Z. F. Production of Graphene Sheets by Direct Dispersion with Aromatic Healing Agents Small 2010, 6, 1100– 1107 DOI: 10.1002/smll.200901978
  
  91
  Production of Graphene Sheets by Direct Dispersion with Aromatic Healing Agents
  
  Zhang, Ming; Parajuli, Rishi R.; Mastrogiovanni, Daniel; Dai, Boya; Lo, Phil; Cheung, William; Brukh, Roman; Chiu, Pui Lam; Zhou, Tao; Liu, Zhongfan; Garfunkel, Eric; He, Huixin
  
  Small (2010), 6 (10), 1100-1107CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A simple and scalable exfoliation approach was developed to produce high-quality single-layer graphene sheets (rather than nonconductive graphene oxide (GO)) in one step, which can be used to fabricate transparent conductive films. Compared to the traditional GO approach to produce conductive graphene sheets, there is no oxidn. and redn. reaction of GO involved. The proposed method decreases the no. of prepn. steps and significantly shortens the prodn. time. In a typical exptl. procedure, graphite powders were exfoliated in a water soln. of pyrene derivs. with the help of sonication. The pyrene derivs. acted as dispersion agents during the exfoliation process and also acted as healing agents and elec. 'glue' during the thermal annealing process. Transparent conductive films fabricated with this approach exhibit a cond. of 181200 S/m (sheet resistance of 778 Ω per square with 90% light transmittance in the 400-800nm wavelength range), the best to date of which we are aware. Transparent conductive graphene films are promising candidates to replace transparent conductive oxides (TCOs) for photovoltaic (PV)/solar cell applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXmsFylurc%253D&md5=543ab8be5a90dc6f9144db794824b734
92. 92
  Schlierf, A.; Yang, H.; Gebremedhn, E.; Treossi, E.; Ortolani, L.; Chen, L.; Minoia, A.; Morandi, V.; Samori, P.; Casiraghi, C. Nanoscale Insight into the Exfoliation Mechanism of Graphene with Organic Dyes: Effect of Charge, Dipole and Molecular Structure Nanoscale 2013, 5, 4205– 4216 DOI: 10.1039/c3nr00258f
  
  92
  Nanoscale insight into the exfoliation mechanism of graphene with organic dyes: effect of charge, dipole and molecular structure
  
  Schlierf, Andrea; Yang, Huafeng; Gebremedhn, Elias; Treossi, Emanuele; Ortolani, Luca; Chen, Liping; Minoia, Andrea; Morandi, Vittorio; Samori, Paolo; Casiraghi, Cinzia; Beljonne, David; Palermo, Vincenzo
  
  Nanoscale (2013), 5 (10), 4205-4216CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  We study the mechanism of surface adsorption of org. dyes on graphene, and successive exfoliation in water of these dye-functionalized graphene sheets. A systematic, comparative study is performed on pyrenes functionalized with an increasing no. of sulfonic groups. By combining exptl. and modeling investigations, we find an unambiguous correlation between the graphene-dye interaction energy, the mol. structure and the amt. of graphene flakes solubilized. The results obtained indicate that the mol. dipole is not important per se, but because it facilitates adsorption on graphene by a "sliding" mechanism of the mol. into the solvent layer, facilitating the lateral displacement of the water mols. collocated between the arom. cores of the dye and graphene. While a large dipole and mol. asymmetry promote the adsorption of the mol. on graphene, the stability and pH response of the suspensions obtained depend on colloidal stabilization, with no significant influence of mol. charging and dipole.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXmvFOqsL8%253D&md5=e21a4ce567c3f6f2e3d5b729c8d76bfb
93. 93
  Song, S. H.; Park, K. H.; Kim, B. H.; Choi, Y. W.; Jun, G. H.; Lee, D. J.; Kong, B. S.; Paik, K. W.; Jeon, S. Enhanced Thermal Conductivity of Epoxy–Graphene Composites by Using Non-Oxidized Graphene Flakes with Non-Covalent Functionalization Adv. Mater. 2013, 25, 732– 737 DOI: 10.1002/adma.201202736
  
  93
  Enhanced Thermal Conductivity of Epoxy-Graphene Composites by Using Non-Oxidized Graphene Flakes with Non-Covalent Functionalization
  
  Song, Sung Ho; Park, Kwang Hyun; Kim, Bo Hyun; Choi, Yong Won; Jun, Gwang Hoon; Lee, Dong Ju; Kong, Byung-Seon; Paik, Kyung-Wook; Jeon, Seokwoo
  
  Advanced Materials (Weinheim, Germany) (2013), 25 (5), 732-737CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  This work suggests a method for obtaining noncovalently functionalized graphene flakes with 1-pyrenebutyric acid that are high sol. in various solvents and these graphene flakes are used to synthesize an epoxy-graphene composite showing enhanced thermal cond.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1OgtrfK&md5=3423bd3ed4fa2dbdc416cc254983e865
94. 94
  Khanra, P.; Uddin, M. E.; Kim, N. H.; Kuila, T.; Lee, S. H.; Lee, J. H. Electrochemical Performance of Reduced Graphene Oxide Surface-Modified with 9-Anthracene Carboxylic Acid RSC Adv. 2015, 5, 6443– 6451 DOI: 10.1039/C4RA12356E
  
  94
  Electrochemical performance of reduced graphene oxide surface-modified with 9-anthracene carboxylic acid
  
  Khanra, Partha; Uddin, Md. Elias; Kim, Nam Hoon; Kuila, Tapas; Lee, Seung Hee; Lee, Joong Hee
  
  RSC Advances (2015), 5 (9), 6443-6451CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  An efficient approach for the prepn. of 9-anthracene carboxylic acid (ACA) modified reduced graphene oxide (rGO) was demonstrated in this study. ACA was used as a surface-modifying agent and underwent a reversible redox reaction. The benzene ring of the ACA anion was attached to the rGO surface via π-π interactions, and the carboxylate anions helped to disperse the hybrid materials in water due to hydrogen bonding. Therefore, water-dispersible, ACA-modified rGO (ACA-rGO) improved the wettability and capacitance performance in aq. electrolyte solns. The morphol. of the ACA-rGO was studied using transmission electron microscopy and at. force microscopy image anal. The dispersion characteristics of the exfoliated materials were investigated using UV-vis spectroscopy anal. The chem. states and natures of the samples were investigated using Fourier-transform IR spectroscopy and XPS. The appearance of a new peak at 288.7 eV in the XPS of ACA-rGO confirmed the successful surface modification of rGO using ACA. Raman spectra were studied to compare the electronic structure and defect concns. in the ACA-rGO with respect to GO. The low intensity and shifted D- and G-bands indicated non-covalent functionalization of rGO with ACA anions. Electrochem. performances of ACA-rGO, rGO, and GO were evaluated in 1 M aq. Na2SO4 electrolyte. The capacitance performance was investigated through galvanometric charge-discharge with ACA-rGO, rGO, and GO in an operating voltage of -1 to 1 V. The range of specific capacitance in the three-electrode system was 610 to 115 F g-1 at a c.d. range of 0.8 to 20 A g-1. In addn., the capacitance performance of ACA-rGO was studied in 1 M Na2SO4 electrolyte using two-electrode systems. The cell capacitance, energy d., and power d. at a c.d. of 0.2 A g-1 of the asym. assembly with multiwall carbon nanotubes were 77 F g-1, 41.3 Wh kg-1, and 200 W kg-1, resp.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFegsL7M&md5=9a8efbfa982e4b237a1418909d127dec
95. 95
  Bose, S.; Kuila, T.; Mishra, A. K.; Kim, N. H.; Lee, J. H. Preparation of Non-Covalently Functionalized Graphene Using 9-Anthracene Carboxylic Acid Nanotechnology 2011, 22, 405603 DOI: 10.1088/0957-4484/22/40/405603
  
  There is no corresponding record for this reference.
96. 96
  Das, S.; Irin, F.; Ahmed, H. S. T.; Cortinas, A. B.; Wajid, A. S.; Parviz, D.; Jankowski, A. F.; Kato, M.; Green, M. J. Non-Covalent Functionalization of Pristine Few-Layer Graphene Using Triphenylene Derivatives for Conductive Poly (Vinyl Alcohol) Composites Polymer 2012, 53, 2485– 2494 DOI: 10.1016/j.polymer.2012.03.012
  
  96
  Non-covalent functionalization of pristine few-layer graphene using triphenylene derivatives for conductive poly(vinyl alcohol) composites
  
  Das, Sriya; Irin, Fahmida; Tanvir Ahmed, H. S.; Cortinas, Abel B.; Wajid, Ahmed S.; Parviz, Dorsa; Jankowski, Alan F.; Kato, Masaru; Green, Micah J.
  
  Polymer (2012), 53 (12), 2485-2494CODEN: POLMAG; ISSN:0032-3861. (Elsevier Ltd.)
  
  In this paper, we demonstrate a facile technique to disperse pristine few-layer graphene (FLG) in water utilizing a triphenylene based stabilizer (C10) that non-covalently functionalizes the surface without micelle formation. The yield of FLG in the final dispersion (0.2 mg FLG/mg C10) is much higher than comparable surfactants and polymers stabilizers. This dispersion is reversible in response to pH changes unlike conventional stabilizers. The C10-stabilized FLG dispersion is also stable against heat and lyophilization. This non-covalent functionalization does not disrupt the pristine structure of the graphene sheets; instead, these coatings allow for stable, aggregation-resistant FLG dispersion, as characterized through TEM. To demonstrate the utility of such dispersions, we prepd. pristine FLG-loaded poly (vinyl alc.) (PVA) composites by a simple soln. casting process. This is the first example of PVA composites based on pristine graphene. These composites have enhanced elec. properties at relatively low filler fraction (0.26 vol% FLG). Moreover, these composites exhibit improved mech. properties established by tensile and hardness tests results; these data suggest anisotropic reinforcement caused by graphene alignment.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XmtFertrg%253D&md5=761d553e5214605b161560a9617e446e
97. 97
  Ghosh, A.; Rao, K. V.; George, S. J.; Rao, C. N. R. Noncovalent Functionalization, Exfoliation, and Solubilization of Graphene in Water by Employing a Fluorescent Coronene Carboxylate Chem. - Eur. J. 2010, 16, 2700– 2704 DOI: 10.1002/chem.200902828
  
  97
  Noncovalent Functionalization, Exfoliation, and Solubilization of Graphene in Water by Employing a Fluorescent Coronene Carboxylate
  
  Ghosh, Anupama; Rao, K. Venkata; George, Subi J.; Rao, C. N. R.
  
  Chemistry - A European Journal (2010), 16 (9), 2700-2704, S2700/1-S2700/6CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  We have demonstrated a simple and efficient method to make stable aq. soln. of graphenes. This is by exploiting noncovalent interactions with a coronene carboxylate acceptor mol. Optical and Raman spectroscopy shows the strong mol. charge transfer interaction with the graphene.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXislKnsL8%253D&md5=df14372ad87d9a666d1621040551456a
98. 98
  Ma, W. S.; Wu, L.; Yang, F.; Wang, S. F. Non-Covalently Modified Reduced Graphene Oxide/Polyurethane Nanocomposites with Good Mechanical and Thermal Properties J. Mater. Sci. 2014, 49, 562– 571 DOI: 10.1007/s10853-013-7736-4
  
  98
  Non-covalently modified reduced graphene oxide/polyurethane nanocomposites with good mechanical and thermal properties
  
  Ma, Wen-Shi; Wu, Li; Yang, Fang; Wang, Shuang-Feng
  
  Journal of Materials Science (2014), 49 (2), 562-571CODEN: JMTSAS; ISSN:0022-2461. (Springer)
  
  Non-covalently modified graphene nanosheets were prepd. by redn. graphene oxide with hydrazine hydrate and simultaneous non-covalent functionalization via 1-allyl-methylimidazolium chloride (AmimCl) ionic liq. Atomic force microscopy revealed that AmimCl ionic liq. modified graphene (IL-G) was well-dispersed in a single exfoliation with a thickness of around 0.96 nm in DMF. Subsequently, the prepd. IL-G nanosheets were incorporated into polyurethane (PU) to fabricate IL-G/PU nanocomposites by soln. blending. X-ray diffraction disclosed an exfoliated morphol. of IL-G nanosheets dispersed in the PU matrix, while the fractured morphol. of the IL-G/PU nanocomposites showed that IL-G nanosheets presented a wrinkled morphol. when dispersed in the matrix. Both techniques revealed homogeneous dispersion and good compatibility of IL-G nanosheets with PU matrix, indicating the existence of interfacial interactions. At 0.608 wt% loadings of IL-G nanosheets, the tensile strength and storage modulus of the composites were increased by 68.5 and 81.1 %, resp. High thermal properties were also achieved at a low loading of IL-G nanosheets. An approx. 40 °C improvement in temp. of 5 % wt. loss and 34 % increase in thermal cond. were obtained at just 0.608 wt% loading of IL-G nanosheets.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsVymsr3O&md5=49efb2f21f4b6d532f3367f23524f89a
99. 99
  Lonkar, S. P.; Bobenrieth, A.; De Winter, J.; Gerbaux, P.; Raquez, J. M.; Dubois, P. A Supramolecular Approach toward Organo-Dispersible Graphene and Its Straightforward Polymer Nanocomposites J. Mater. Chem. 2012, 22, 18124– 18126 DOI: 10.1039/c2jm34234k
  
  There is no corresponding record for this reference.
100. 100
  Yang, Y. K.; He, C. E.; Peng, R. G.; Baji, A.; Du, X. S.; Huang, Y. L.; Xie, X. L.; Mai, Y. W. Non-Covalently Modified Graphene Sheets by Imidazolium Ionic Liquids for Multifunctional Polymer Nanocomposites J. Mater. Chem. 2012, 22, 5666– 5675 DOI: 10.1039/c2jm16006d
  
  100
  Non-covalently modified graphene sheets by imidazolium ionic liquids for multifunctional polymer nanocomposites
  
  Yang, Ying-Kui; He, Cheng-En; Peng, Ren-Gui; Baji, Avinash; Du, Xu-Sheng; Huang, Yuan-Li; Xie, Xiao-Lin; Mai, Yiu-Wing
  
  Journal of Materials Chemistry (2012), 22 (12), 5666-5675CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)
  
  Chem. redn. of graphite oxide (GO) to produce graphene nanosheets often results in irreversible agglomeration and pptn. Herein, stable well-dispersed graphene sheets in solvents were obtained by simultaneous functionalization and redn. of GO under alk. conditions, in the presence of sodium borohydride and imidazolium ionic liqs. (Imi-ILs) contg. two vinyl-benzyl groups. In this case, pos. charged imidazolium groups of Imi-ILs underwent ion-exchange with neg. charged GO sheets and were linked to their edges, while Imi-ILs were non-covalently attached onto the large surfaces of graphene through π-π and/or cation-π stacking interactions. The vinyl-benzyl reactive sites were then copolymd. in situ with Me methacrylate to fabricate graphene/poly(Me methacrylate) (PMMA) composites. Functionalized graphene sheets were uniformly dispersed in the PMMA matrix and contributed to large increases in storage modulus (+58.3%) and glass transition temp. (+19.2 °C) at 2.08 vol.% loading. High elec. cond. was also achieved at graphene loading levels beyond 1 vol.% (ca. 2.55 Sm-1) with a low percolation threshold (0.25 vol.%) for the composites. Hence, a general methodol. which facilitates the development of a multifunctional advanced material has been successfully established. This can be extended to other vinyl polymer-based composites contg. graphene.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XjtVGms7g%253D&md5=109f62d73d0f22818673ebc89ee9d95f
101. 101
  Bari, R.; Tamas, G.; Irin, F.; Aquino, A. J. A.; Green, M. J.; Quitevis, E. L. Direct Exfoliation of Graphene in Ionic Liquids with Aromatic Groups Colloids Surf., A 2014, 463, 63– 69 DOI: 10.1016/j.colsurfa.2014.09.024
  
  101
  Direct exfoliation of graphene in ionic liquids with aromatic groups
  
  Bari, Rozana; Tamas, George; Irin, Fahmida; Aquino, Adelia J. A.; Green, Micah J.; Quitevis, Edward L.
  
  Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2014), 463 (), 63-69CODEN: CPEAEH; ISSN:0927-7757. (Elsevier B.V.)
  
  Novel ionic liqs. (ILs) were designed and synthesized to contain arom. groups on the imidazolium cation that non-covalently interact with graphene surfaces. This route enables the dispersion of pristine graphene without covalent functionalization or an additive stabilizer; such dispersions are stable against aggregation and display high concn. values. We find that ILs without these arom. groups are less effective in graphene dispersion, and the dispersed graphene concn. increases with increasing interaction between the cation and graphene surface. D. functional theory (DFT-D3) calcns. support the exptl. observations and provide a foundation for predictive modeling of IL design for optimal graphene dispersions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1ems7rM&md5=3676b4f736299be01f7b850163901dae
102. 102
  Zhang, B.; Ning, W.; Zhang, J.; Qiao, X.; Zhang, J.; He, J.; Liu, C. Y. Stable Dispersions of Reduced Graphene Oxide in Ionic Liquids J. Mater. Chem. 2010, 20, 5401– 5403 DOI: 10.1039/c0jm01029d
  
  102
  Stable dispersions of reduced graphene oxide in ionic liquids
  
  Zhang, Baoqing; Ning, Wei; Zhang, Jinming; Qiao, Xin; Zhang, Jun; He, Jiasong; Liu, Chen-Yang
  
  Journal of Materials Chemistry (2010), 20 (26), 5401-5403CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)
  
  Starting with graphene oxide, the authors successfully prepd. stable dispersions of reduced graphene oxide (RGO) in three hydrophilic ionic liqs. (ILs) at relatively high concn. without using any surfactants/stabilizers.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXnslyqurk%253D&md5=d9dd76e378b766fdd8af901c16e07da1
103. 103
  Kim, T. Y.; Lee, H. W.; Kim, J. E.; Suh, K. S. Synthesis of Phase Transferable Graphene Sheets Using Ionic Liquid Polymers ACS Nano 2010, 4, 1612– 1618 DOI: 10.1021/nn901525e
  
  103
  Synthesis of phase transferable graphene sheets using ionic liquid polymers
  
  Kim, TaeYoung; Lee, HyunWook; Kim, JongEun; Suh, Kwang S.
  
  ACS Nano (2010), 4 (3), 1612-1618CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  A practical route to the prodn. of soln. phase transferable graphene sheets using ionic liq. polymers (PIL) as a transferring medium is developed. Chem. converted graphene sheets decorated with PIL were found to be stable against the chem. redn. and well dispersed in the aq. phase without any agglomeration. Upon the anion exchange of the PIL on graphene sheets, these PIL-modified graphene sheets in aq. phase are readily transferred into the org. phase by changing their properties from hydrophilic to hydrophobic.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhvF2ks7k%253D&md5=aa1088c64b0f360fb050000cbb466fae
104. 104
  Geng, J.; Jung, H. T. Porphyrin Functionalized Graphene Sheets in Aqueous Suspensions: From the Preparation of Graphene Sheets to Highly Conductive Graphene Films J. Phys. Chem. C 2010, 114, 8227– 8234 DOI: 10.1021/jp1008779
  
  104
  Porphyrin Functionalized Graphene Sheets in Aqueous Suspensions: From the Preparation of Graphene Sheets to Highly Conductive Graphene Films
  
  Geng, Jianxin; Jung, Hee-Tae
  
  Journal of Physical Chemistry C (2010), 114 (18), 8227-8234CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
  
  Graphene has a unique structure and potential applications in nanoelectronics, nanocomposites, conductive and transparent films, etc. Synthesis of graphene is one of the major research efforts to make rapid developments in graphene research. A new method, that makes use of the π-π interactions between porphyrin and graphene to stabilize the chem. converted graphene (CCG), was developed for prepn. of CCG via chem. redn. of exfoliated graphene oxide (GO). Optical absorption spectroscopy measurement shows that π-π interactions take place between GO and porphyrins, 5,10,15,20-tetraphenyl-21H, 23H-porphine-p,p',p'',p'''-tetrasulfonic acid tetrasodium hydrate (TPP-SO3Na) and 5,10,15,20-tetrakis(4-trimethylammoniophenyl) porphyrin tetra(p-toluenesulfonate). TPP-SO3Na functionalized CCG can form a stable aq. suspension due to the electrostatic repulsion between the CCG sheets, which results from the aggregation of TPP-SO3Na mols. on the surfaces of the CCG sheets. Atomic force microscope observation shows that the TPP-SO3Na functionalized CCG sheets are single-layer entities, which are sandwiched by TPP-SO3Na mols. Conductive graphene films with various thicknesses were prepd. by using the TPP-SO3Na functionalized CCG suspension via a vacuum filtration method. The change of the sheet resistance of the CCG films follows the percolation mechanism. A sheet resistance as low as ∼5 KΩ·-1 of the CCG films with 80% transparency at 550 nm was obtained. Such low sheet resistance is contributed to improved sp2 networks of the CCG sheets, low contact resistance between the CCG sheets, and the healing of the defective vacancies on CCG sheets by porphyrin mols., which are achieved by combination of chem. redn. of GO and thermal annealing of the resultant CCG films.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXkslKluro%253D&md5=1ded06b2409be43e61b84a4b8a32ecdb
105. 105
  Xu, Y.; Zhao, L.; Bai, H.; Hong, W.; Li, C.; Shi, G. Chemically Converted Graphene Induced Molecular Flattening of 5,10,15,20-Tetrakis(1-methyl-4-pyridinio)porphyrin and Its Application for Optical Detection of Cadmium(II) Ions J. Am. Chem. Soc. 2009, 131, 13490– 13497 DOI: 10.1021/ja905032g
  
  105
  Chemically Converted Graphene Induced Molecular Flattening of 5,10,15,20-Tetrakis(1-methyl-4-pyridinio)porphyrin and Its Application for Optical Detection of Cadmium(II) Ions
  
  Xu, Yuxi; Zhao, Lu; Bai, Hua; Hong, Wenjing; Li, Chun; Shi, Gaoquan
  
  Journal of the American Chemical Society (2009), 131 (37), 13490-13497CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  Complexation of cationic 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin (TMPyP) and neg. charged chem. converted graphene (CCG) sheets was performed by simply mixing the dild. aq. solns. of both components. During this process, a large bathochromic shift of porphyrin Soret band from 421 to 458 nm was obsd., which is attributed to the flattening of TMPyP mols. induced by CCG through electrostatic and π-π stacking cooperative interactions. Also, the coordination reaction between TMPyP and Cd2+ ions was greatly accelerated from 20 h to 8 min under ambient conditions by introducing CCG sheets. From this phenomenon, the authors used the complex of TMPyP and CCG as an optical probe for rapid and selective detection of Cd2+ ions in aq. media.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtVGgu77E&md5=ac3eda034fdeb89671b9a4336de7f041
106. 106
  Arramel, A.; Castellanos-Gomez, B.; van Wees, J. Band Gap Opening of Graphene by Noncovalent π-π Interaction with Porphyrins Graphene 2013, 2, 102– 108 DOI: 10.4236/graphene.2013.23015
  
  There is no corresponding record for this reference.
107. 107
  Bozkurt, E.; Acar, M.; Onganer, Y.; Meral, K. Rhodamine 101-Graphene Oxide Composites in Aqueous Solution: the Fluorescence Quenching Process of Rhodamine 101 Phys. Chem. Chem. Phys. 2014, 16, 18276– 18281 DOI: 10.1039/C4CP01492H
  
  There is no corresponding record for this reference.
108. 108
  Jiang, B. P.; Hu, L. F.; Wang, D. J.; Ji, S. C.; Shen, X. C.; Liang, H. Graphene Loading Water-Soluble Phthalocyanine for Dual-Modality Photothermal/Photodynamic Therapy via a One-Step Method J. Mater. Chem. B 2014, 2, 7141– 7148 DOI: 10.1039/C4TB01038H
  
  108
  Graphene loading water-soluble phthalocyanine for dual-modality photothermal/photodynamic therapy via a one-step method
  
  Jiang, Bang-Ping; Hu, Lan-Fang; Wang, Dong-Jin; Ji, Shi-Chen; Shen, Xing-Can; Liang, Hong
  
  Journal of Materials Chemistry B: Materials for Biology and Medicine (2014), 2 (41), 7141-7148CODEN: JMCBDV; ISSN:2050-7518. (Royal Society of Chemistry)
  
  In this paper, we present a new and facile one-step method for the fabrication of a water-sol. graphene-phthalocyanine (GR-Pc) hybrid material by simply sonicating GR with a hydrophilic Pc, tetrasulfonic acid tetrasodium salt copper phthalocyanine (TSCuPc). In the resultant hybrid material, TSCuPc is coated on the skeleton of pristine GR via non-covalently π-π interaction, detailedly characterized by UV-vis/Raman spectra, XPS, etc. The obtained GR-Pc hybrid (GR-TSCuPc) is applied for photothermal therapy (PTT) and photodynamic therapy (PDT). In this PTT/PDT system, both GR and TSCuPc operate as multifunctional agents: GR acts as a photosensitizer carrier and PTT agent, while TSCuPc acts as a hydrophilic PDT agent. Furthermore, the results of cell viability show that the phototherapy effect of GR-TSCuPc is observably higher than that of free TSCuPc, indicating that combined noninvasive PTT/PDT exhibits better anti-cancer efficacy in vitro. Such results highlight that this work provide a facile method to develop efficacious dual-modality carbon nanoplatform for developing cancer therapeutics.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVSiu7nN&md5=72f90125bb643d61ae339a256a2d69a1
109. 109
  Chien, C. T.; Li, S. S.; Lai, W. J.; Yeh, Y. C.; Chen, H. A.; Chen, I. S.; Chen, L. C.; Chen, K. H.; Nemoto, T.; Isoda, S. Tunable Photoluminescence from Graphene Oxide Angew. Chem., Int. Ed. 2012, 51, 6662– 6666 DOI: 10.1002/anie.201200474
  
  109
  Tunable Photoluminescence from Graphene Oxide
  
  Chien, Chih-Tao; Li, Shao-Sian; Lai, Wei-Jung; Yeh, Yun-Chieh; Chen, Hsin-An; Chen, I.-Shen; Chen, Li-Chyong; Chen, Kuei-Hsien; Nemoto, Takashi; Isoda, Seiji; Chen, Mingwei; Fujita, Takeshi; Eda, Goki; Yamaguchi, Hisato; Chhowalla, Manish; Chen, Chun-Wei
  
  Angewandte Chemie, International Edition (2012), 51 (27), 6662-6666, S6662/1-S6662/10CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Graphene oxide (GO) suspensions are prepd. that exhibit virtually all of the PL features obsd. by different groups, through careful and gradual redn. of the GO. The systematic evolution of the electronic structure and comprehensive anal. of steady-state and transient PL along with photoluminescence excitation (PLE) spectroscopy measurements indicate that two different types of electronically excited states are responsible for the obsd. emission characteristics.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XnsVGks7Y%253D&md5=c14a42d2edf4e74ef31c13c531636fa8
110. 110
  Zhang, X. F.; Shao, X.; Liu, S. Dual Fluorescence of Graphene Oxide: A Time-Resolved Study J. Phys. Chem. A 2012, 116, 7308– 7313 DOI: 10.1021/jp301755b
  
  110
  Dual Fluorescence of Graphene Oxide: A Time-Resolved Study
  
  Zhang, Xian-Fu; Shao, Xiaona; Liu, Suping
  
  Journal of Physical Chemistry A (2012), 116 (27), 7308-7313CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)
  
  The fluorescence properties of graphene oxide (GO) was studied by recording the fluorescence lifetime, fluorescence emission, and excitation spectra, as well as UV-visible and near-IR absorption spectra. For the first time, we showed that a blue band (ca. 440 nm) and a long wavelength (LW) band (ca. 700 nm) are coexistent, which can be recorded simultaneously by controlling concn., excitation wavelength, and pH values. Two bands are closely related by the protonation or deprotonation of GO. The blue band is favored by low GO concn., short excitation wavelength, and high pH value, while the LW band is favored by low pH and long excitation wavelength. To reveal the nature of the dual emission of GO, the fluorescence lifetimes under various conditions were also measured. The blue band contains three emitting components; one of them has a lifetime as long as 10 ns, and its emitting intensity is fairly sensitive to pH, showing the potential for applications in sensing H+ and fluorescence lifetime imaging. Combining the results under various conditions, we conclude that the electronic transition for this component is very likely due to n-π* transition. The LW band contains two main emitting components (0.2 and 2.1 ns) that also appear in the blue band as minor contributors; the related emission is assigned to π-π* transition. In summary, GO emission is of broadband (300-1250 nm), long-lived, pH sensitive, and excitation wavelength dependent. This makes it easily tailored for versatile applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XosVWitr4%253D&md5=d05cdbbf9dd74c16e0503243766cdcf2
111. 111
  Loh, K. P.; Bao, Q. L.; Eda, G.; Chhowalla, M. Graphene Oxide as a Chemically Tunable Platform for Optical Applications Nat. Chem. 2010, 2, 1015– 1024 DOI: 10.1038/nchem.907
  
  111
  Graphene oxide as a chemically tunable platform for optical applications
  
  Loh, Kian Ping; Bao, Qiaoliang; Eda, Goki; Chhowalla, Manish
  
  Nature Chemistry (2010), 2 (12), 1015-1024CODEN: NCAHBB; ISSN:1755-4330. (Nature Publishing Group)
  
  A review. Chem. derived graphene oxide (GO) is an atomically thin sheet of graphite that has traditionally served as a precursor for graphene, but is increasingly attracting chemists for its own characteristics. It is covalently decorated with O-contg. functional groups - either on the basal plane or at the edges - so that it contains a mixt. of sp2- and sp3-hybridized C atoms. Manipulation of the size, shape and relative fraction of the sp2-hybridized domains of GO by redn. chem. provides opportunities for tailoring its optoelectronic properties. For example, as-synthesized GO is insulating but controlled deoxidn. leads to an elec. and optically active material that is transparent and conducting. In contrast to pure graphene, GO is fluorescent over a broad range of wavelengths, owing to its heterogeneous electronic structure. The recent advances in optical properties of chem. derived GO, as well as new phys. and biol. applications are highlighted.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhsVOrsLzK&md5=6292b431a16bb3622b87145aa8db87ab
112. 112
  Iliut, M.; Gabudean, A. M.; Leordean, C.; Simon, T.; Teodorescu, C. M.; Astilean, S. Riboflavin Enhanced Fluorescence of Highly Reduced Graphene Oxide Chem. Phys. Lett. 2013, 586, 127– 131 DOI: 10.1016/j.cplett.2013.09.032
  
  There is no corresponding record for this reference.
113. 113
  Fernandez-Merino, M. J.; Paredes, J. I.; Villar-Rodil, S.; Guardia, L.; Solis-Fernandez, P.; Salinas-Torres, D.; Cazorla-Amoros, D.; Morallon, E.; Martinez-Alonso, A.; Tascon, J. M. D. Investigating the Influence of Surfactants on the Stabilization of Aqueous Reduced Graphene Oxide Dispersions and the Characteristics of Their Composite Films Carbon 2012, 50, 3184– 3194 DOI: 10.1016/j.carbon.2011.10.039
  
  There is no corresponding record for this reference.
114. 114
  Bourlinos, A. B.; Georgakilas, V.; Zboril, R.; Steriotis, T. A.; Stubos, A. K.; Trapalis, C. Aqueous-Phase Exfoliation of Graphite in the Presence of Polyvinylpyrrolidone for the Production of Water-Soluble Graphenes Solid State Commun. 2009, 149, 2172– 2176 DOI: 10.1016/j.ssc.2009.09.018
  
  114
  Aqueous-phase exfoliation of graphite in the presence of polyvinylpyrrolidone for the production of water-soluble graphenes
  
  Bourlinos, Athanasios B.; Georgakilas, Vasilios; Zboril, Radek; Steriotis, Theodore A.; Stubos, Athanasios K.; Trapalis, Christos
  
  Solid State Communications (2009), 149 (47-48), 2172-2176CODEN: SSCOA4; ISSN:0038-1098. (Elsevier Ltd.)
  
  Treatment of cryst. graphite fine powder with an aq. soln. of the harmless and versatile substance polyvinylpyrrolidone under sonication results in water-sol., polymer-protected graphene single layers without oxidn. or destruction of the sp2 character of the carbon core. The liq.-phase extn. of graphene monolayers was evidenced by TEM and AFM techniques, while their graphitic character was checked with Raman spectroscopy. Besides PVP, the water-sol. biopolymers albumin and sodic CM-cellulose were also employed successfully in the aq.-phase exfoliation of graphite, thereby supporting the generic character of the present method using a variety of suitable polymeric extractants.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtlagtbrF&md5=00ba4742b628f3496b7d01358722b42d
115. 115
  Liang, Y.; Wu, D.; Feng, X.; Mullen, K. Dispersion of Graphene Sheets in Organic Solvent Supported by Ionic Interactions Adv. Mater. 2009, 21, 1– 5 DOI: 10.1002/adma.200803160
  
  There is no corresponding record for this reference.
116. 116
  Carrasco, P. M.; Montes, S.; Garcia, I.; Borghei, M.; Jiang, H.; Odriozola, I.; Cabanero, G.; Ruiz, V. High-Concentration Aqueous Dispersions of Graphene Produced by Exfoliation of Graphite Using Cellulose Nanocrystals Carbon 2014, 70, 157– 163 DOI: 10.1016/j.carbon.2013.12.086
  
  116
  High-concentration aqueous dispersions of graphene produced by exfoliation of graphite using cellulose nanocrystals
  
  Carrasco, Pedro M.; Montes, Sarah; Garcia, Ignacio; Borghei, Maryam; Jiang, Hua; Odriozola, Ibon; Cabanero, German; Ruiz, Virginia
  
  Carbon (2014), 70 (), 157-163CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  Stable high-concn. aq. dispersions (>1 mg ml-1) of single and few-layer graphene flakes were produced by direct exfoliation of graphite using cellulose nanocrystals (CNC). Biodegradable and widely available from renewable sources, CNC have proven to be very efficient graphene stabilizers even at low concns. (0.2 mg ml-1), thus enabling remarkably high graphene/CNC ratios (up to 3.8).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1Glt78%253D&md5=69a5203008d0f87cf8135439c1d27cab
117. 117
  Lotya, M.; King, P. J.; Khan, U.; De, S.; Coleman, J. N. High-Concentration, Surfactant-Stabilized Graphene Dispersions ACS Nano 2010, 4, 3155– 3162 DOI: 10.1021/nn1005304
  
  117
  High-Concentration, Surfactant-Stabilized Graphene Dispersions
  
  Lotya, Mustafa; King, Paul J.; Khan, Umar; De, Sukanta; Coleman, Jonathan N.
  
  ACS Nano (2010), 4 (6), 3155-3162CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  A method is presented to produce graphene dispersions, stabilized in water by the surfactant sodium cholate, at concns. up to 0.3 mg/mL. The process uses low power sonication for long times (up to 400 h) followed by centrifugation to yield stable dispersions. The dispersed concn. increases with sonication time while the best quality dispersions are obtained for centrifugation rates between 500 and 2000 rpm. Detailed TEM anal. shows the flakes to consist of 1-10 stacked monolayers with up to 20% of flakes contg. just one layer. The av. flake consists of ∼4 stacked monolayers and has length and width of ∼1 μm and ∼400 nm, resp. These dimensions are surprisingly stable under prolonged sonication. However, the mean flake length falls from ∼1 μm to ∼500 nm as the centrifugation rate is increased from 500 to 5000 rpm. Raman spectroscopy shows the flake bodies to be relatively defect-free for centrifugation rates <2000 rpm. The dispersions can be easily cast into high-quality, free-standing films. The method extends the scope for scalable liq.-phase processing of graphene for a wide range of applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXlslyns7k%253D&md5=2e78a09fd09b3a97d5545653cbf5936b
118. 118
  Lotya, M.; Hernandez, Y.; King, P. J.; Smith, R. J.; Nicolosi, V.; Karlsson, L. S.; Blighe, F. M.; De, S.; Wang, Z.; McGovern, I. T. Liquid Phase Production of Graphene by Exfoliation of Graphite in Surfactant/Water Solutions J. Am. Chem. Soc. 2009, 131, 3611– 3620 DOI: 10.1021/ja807449u
  
  118
  Liquid Phase Production of Graphene by Exfoliation of Graphite in Surfactant/Water Solutions
  
  Lotya, Mustafa; Hernandez, Yenny; King, Paul J.; Smith, Ronan J.; Nicolosi, Valeria; Karlsson, Lisa S.; Blighe, Fiona M.; De, Sukanta; Wang, Zhiming; McGovern, I. T.; Duesberg, Georg S.; Coleman, Jonathan N.
  
  Journal of the American Chemical Society (2009), 131 (10), 3611-3620CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  The authors demonstrated a method to disperse and exfoliate graphite to give graphene suspended in water-surfactant solns. Optical characterization of these suspensions allowed the partial optimization of the dispersion process. TEM showed the dispersed phase to consist of small graphitic flakes. More than 40% of these flakes had <5 layers with ∼3% of flakes consisting of monolayers. At. resoln. TEM shows the monolayers to be generally free of defects. The dispersed graphitic flakes are stabilized against reaggregation by Coulomb repulsion due to the adsorbed surfactant. The authors use DLVO and Hamaker theory to describe this stabilization. However, the larger flakes tend to sediment out over ∼6 wk, leaving only small flakes dispersed. It is possible to form thin films by vacuum filtration of these dispersions. Raman and IR spectroscopic anal. of these films suggests the flakes to be largely free of defects and oxides, although XPS shows evidence of a small oxide population. Individual graphene flakes can be deposited onto mica by spray coating, allowing statistical anal. of flake size and thickness. Vacuum filtered films are reasonably conductive and are semitransparent. Further improvements may result in the development of cheap transparent conductors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXit1ersrk%253D&md5=525945f5df60169f74d171b72894d9d3
119. 119
  Cai, M.; Thorpe, D.; Adamson, D. H.; Schniepp, H. C. Methods of Graphite Exfoliation J. Mater. Chem. 2012, 22, 24992– 25002 DOI: 10.1039/c2jm34517j
  
  119
  Methods of graphite exfoliation
  
  Cai, Minzhen; Thorpe, Daniel; Adamson, Douglas H.; Schniepp, Hannes C.
  
  Journal of Materials Chemistry (2012), 22 (48), 24992-25002CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)
  
  A review. For applications of two-dimensional graphene, com. viable sources are necessary. Exfoliation from bulk, stacked graphite is the most economical way to achieve large quantities of single layer graphene. A no. of methods have been developed to achieve exfoliation of graphite, each with advantages and disadvantages. In this review, we describe current exfoliation methods and techniques used to produce single layer materials from graphite precursors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs12ls7rK&md5=574d6181655b8628d94387327410a170
120. 120
  Yang, Q.; Pan, X.; Huang, F.; Li, K. Fabrication of High-Concentration and Stable Aqueous Suspensions of Graphene Nanosheets by Noncovalent Functionalization with Lignin and Cellulose Derivatives J. Phys. Chem. C 2010, 114, 3811– 3816 DOI: 10.1021/jp910232x
  
  120
  Fabrication of High-Concentration and Stable Aqueous Suspensions of Graphene Nanosheets by Noncovalent Functionalization with Lignin and Cellulose Derivatives
  
  Yang, Qiang; Pan, Xuejun; Huang, Fang; Li, Kecheng
  
  Journal of Physical Chemistry C (2010), 114 (9), 3811-3816CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
  
  Stable aq. suspensions of graphene (G) nanosheets with high concn. (0.6-2 mg/mL) were prepd. through chem. redn. of exfoliated graphite oxide (EGO) with the aid of sodium lignosulfonate (SLS), sodium CM-cellulose (SCMC), and pyrene-contg. hydroxypropyl cellulose (HPC-Py). The noncovalently functionalized graphene nanosheets with a 3.3 ± 1.4 nm av. thickness were characterized using UV-visible spectroscopy, fluorescence spectroscopy, at. force microscopy, attenuated total reflectance micro-FTIR spectroscopy, and Raman spectroscopy.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhvFWgu70%253D&md5=025c22accd51fe719a9c7a8b1da09fe1
121. 121
  Choi, E. Y.; Han, T. H.; Hong, J.; Kim, J. E.; Lee, S. H.; Kim, H. W.; Kim, S. O. Noncovalent Functionalization of Graphene with End-Functional Polymers J. Mater. Chem. 2010, 20, 1907– 1912 DOI: 10.1039/b919074k
  
  121
  Noncovalent functionalization of graphene with end-functional polymers
  
  Choi, Eun-Young; Han, Tae Hee; Hong, Jihyun; Kim, Ji Eun; Lee, Sun Hwa; Kim, Hyun Wook; Kim, Sang Ouk
  
  Journal of Materials Chemistry (2010), 20 (10), 1907-1912CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)
  
  Stable dispersion of reduced graphene in various org. solvents was achieved via noncovalent functionalization with amine-terminated polymers. An aq. dispersion of reduced graphene was prepd. by chem. redn. of graphene oxide in aq. media and was vacuum filtered to generate reduced graphene sheets. Good solvents and nonsolvents for the dried reduced graphene were evaluated using a soly. test. To achieve stable dispersion in the evaluated nonsolvents, amine-terminated polystyrene was noncovalently functionalized to the graphene, while graphene sheets were phase transferred via sonication from aq. phase to the org. nonsolvent phase, including the amine-terminated polymers. Thorough FTIR and Raman spectroscopy study verified that the protonated amine terminal group of polystyrene underwent noncovalent functionalization to the carboxylate groups at the graphene surface, providing the high dispersibility in various org. media.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXitleitrc%253D&md5=4a7ecfe16241f5895c69e628c875e6d5
122. 122
  Lian, M.; Fan, J.; Shi, Z.; Li, H.; Yin, J. Kevlar-Functionalized Graphene Nanoribbon for Polymer Reinforcement Polymer 2014, 55, 2578– 2587 DOI: 10.1016/j.polymer.2014.03.059
  
  122
  Kevlar-functionalized graphene nanoribbon for polymer reinforcement
  
  Lian, Min; Fan, Jinchen; Shi, Zixing; Li, Hong; Yin, Jie
  
  Polymer (2014), 55 (10), 2578-2587CODEN: POLMAG; ISSN:0032-3861. (Elsevier Ltd.)
  
  Multiwalled carbon nanotubes (MWCNTs) have been widely used as reinforcement fillers in past decades. However, the reinforcement effect has been greatly hindered by the limited available interface area (AIA) with polymer matrixes for polymer composites. Successively, the method of oxidative unzipping MWCNTs into graphene nanoribbons (GNRs) was demonstrated to be the effective way for addressing the inherent drawback of MWCNTs. However, the GNRs are easy to agglomerate in polymer matrix even at relatively low loading amt. In this paper, we found that the functionalization of GNRs with Kevlar can significantly improve the dispersion state of GNRs in polymer matrix. Consequently, Kevlar-functionalized graphene nanoribbons (KGNRs) were successfully prepd. through non-covalent functionalization of π-π stacking interaction between the arom. area of Kevlar and the graphitic surface of GNRs. As-prepd. KGNRs were characterized by FT-IR, TGA, XRD and TEM measurements. Poly(vinyl chloride) (PVC) and poly(Me methacrylate) (PMMA) were selected as model polymers to investigate the reinforcement effect of KGNRs. The KGNRs could be well dispersed in PVC and PMMA matrixes at relatively high loading level. Meantime, the ultimate tensile strengths and Young's modulus of KGNRs/PVC and KGNRs/PMMA composite films were significantly improved. Based on the observations above, KGNRs hold great promise in many potential applications in the future.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXmsVWgsb4%253D&md5=76f581e8db98af69491a17fd5bf23092
123. 123
  Zhang, J.; Xu, Y.; Cui, L.; Fu, A.; Yang, W.; Barrow, C.; Liu, J. Mechanical Properties of Graphene Films Enhanced by Homo-Telechelic Functionalized Polymer Fillers via p–p Stacking Interactions Composites, Part A 2015, 71, 1– 8 DOI: 10.1016/j.compositesa.2014.12.013
  
  123
  Mechanical properties of graphene films enhanced by homo-telechelic functionalized polymer fillers via π-π stacking interactions
  
  Zhang, Jizhen; Xu, Yuanhong; Cui, Liang; Fu, Aiping; Yang, Wenrong; Barrow, Colin; Liu, Jingquan
  
  Composites, Part A: Applied Science and Manufacturing (2015), 71 (), 1-8CODEN: CASMFJ; ISSN:1359-835X. (Elsevier Ltd.)
  
  Most researches on graphene/polymer composites are focusing on improving the mech. and elec. properties of polymers at low graphene content instead of paying attention to constructing graphene's macroscopic structures. In current study, the homo-telechelic functionalized polyethylene glycols (FPEGs) were tailored with π-orbital-rich groups (namely Ph, pyrene and di-pyrene) via esterification reactions, which enhanced the interaction between polyethylene glycol (PEG) mols. and chem. reduced graphene oxide (RGO) sheets. The π-π stacking interactions between graphene sheets and π-orbital-rich groups endowed the composite films with enhanced tensile strength and tunable elec. cond. The formation of graphene network structure mediated by the FPEGs fillers via π-π stacking non-covalent interactions should account for the exptl. results. The exptl. investigations were also complemented with theor. calcn. using a d. functional theory. Atomic force microscope, scanning electron microscope, X-ray diffraction, NMR, thermal gravimetric anal., UV-vis and fluorescence spectroscopy were used to monitor the step-wise prepn. of graphene composite films.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXovFyksA%253D%253D&md5=76663e335e198a689ed018d0cda286bb
124. 124
  Chandra, V.; Kim, K. S. Highly Selective Adsorption of Hg²⁺ by Polypyrrole-Reduced Graphene Oxide Composite Chem. Commun. 2011, 47, 3942– 3944 DOI: 10.1039/c1cc00005e
  
  There is no corresponding record for this reference.
125. 125
  Stankovich, S.; Piner, R. D.; Chen, X.; Wu, N.; Nguyen, S. T.; Ruoff, R. S. Stable Aqueous Dispersions of Graphitic Nanoplatelets via the Reduction of Exfoliated Graphite Oxide in the Presence of Poly(sodium 4-styrenesulfonate) J. Mater. Chem. 2006, 16, 155– 158 DOI: 10.1039/B512799H
  
  125
  Stable aqueous dispersions of graphitic nanoplatelets via the reduction of exfoliated graphite oxide in the presence of poly(sodium 4-styrenesulfonate)
  
  Stankovich, Sasha; Piner, Richard D.; Chen, Xinqi; Wu, Nianqiang; Nguyen, SonBinh T.; Ruoff, Rodney S.
  
  Journal of Materials Chemistry (2006), 16 (2), 155-158CODEN: JMACEP; ISSN:0959-9428. (Royal Society of Chemistry)
  
  For the first time, stable aq. dispersions of polymer-coated graphitic nanoplatelets can be prepd. via an exfoliation/in-situ redn. of graphite oxide in the presence of poly(sodium 4-styrenesulfonate).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXhtlanurzO&md5=f466af7e066bcec151c0575b69cfeaae
126. 126
  Bai, H.; Xu, Y.; Zhao, L.; Li, C.; Shi, G. Non-Covalent Functionalization of Graphene Sheets by Sulfonated Polyaniline Chem. Commun. 2009, 1667– 1669 DOI: 10.1039/b821805f
  
  126
  Non-covalent functionalization of graphene sheets by sulfonated polyaniline
  
  Bai, Hua; Xu, Yuxi; Zhao, Lu; Li, Chun; Shi, Gaoquan
  
  Chemical Communications (Cambridge, United Kingdom) (2009), (13), 1667-1669CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)
  
  A review. Graphene sheets were stably dispersed in water by functionalization with sulfonated polyaniline (SPANI), and the composite film of SPANI-functionalized graphene showed improved electrochem. stability and enhanced electrocatalytic activity.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXjt1ant7g%253D&md5=225d266c0b9370f5a47ab02eeadc93fd
127. 127
  Matos, C. F.; Galembeck, F.; Zarbin, A. J. G. Multifunctional and Environmentally Friendly Nanocomposites between Natural Rubber and Graphene or Graphene Oxide Carbon 2014, 78, 469– 479 DOI: 10.1016/j.carbon.2014.07.028
  
  127
  Multifunctional and environmentally friendly nanocomposites between natural rubber and graphene or graphene oxide
  
  Matos, Carolina F.; Galembeck, Fernando; Zarbin, Aldo J. G.
  
  Carbon (2014), 78 (), 469-479CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  This work describes a green route to multifunctional nanocomposite materials composed of natural rubber (NR) latex and graphene (rGO) or graphene oxide (GO). Aq. solns. with different concns. of GO and rGO (prepd. with the surfactant cetyltrimethylammonium bromide - CTAB) were mixed with natural rubber latex under magnetic stirring followed by sonication. The slurries obtained after casting were dried in an oven in air at 70 °C for 24 h. The nanocomposites were characterized by TEM and SEM, AFM and KFM. The thermal, elec. and mech. properties were evaluated using TGA, resistivity measurements (four-point) and DMA. Swelling tests were performed using three solvents with different polarities: xylene, isopropanol and water. The inclusion of filler networks in the polymeric matrixes provided significant improvements in the elec., chem. and mech. properties, in comparison to the unfilled polymer. In addn., the nanocomposites proved to be biodegradable.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1entrzE&md5=3870ef725dbf0e4b97b8d330aec6a2d8
128. 128
  Hsiao, S. T.; Ma, C. C. M.; Tien, H. W.; Liao, W. H.; Wang, Y. S.; Li, S. M.; Huang, Y. C. Using a Non-Covalent Modification to Prepare a High Electromagnetic Interference Shielding Performance Graphene Nanosheet/Water-Borne Polyurethane Composite Carbon 2013, 60, 57– 66 DOI: 10.1016/j.carbon.2013.03.056
  
  128
  Using a non-covalent modification to prepare a high electromagnetic interference shielding performance graphene nanosheet/water-borne polyurethane composite
  
  Hsiao, Sheng-Tsung; Ma, Chen-Chi M.; Tien, Hsi-Wen; Liao, Wei-Hao; Wang, Yu-Sheng; Li, Shin-Ming; Huang, Yu-Chin
  
  Carbon (2013), 60 (), 57-66CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  The authors prepd. flexible, lightwt., and high electromagnetic interference (EMI) shielding performance graphene nanosheet (GNS)/water-borne polyurethane (WPU) composites. WPU, with sulfonate functional groups, was used as the polymer matrix. By adsorbing the cationic surfactant (stearyl tri-Me ammonium chloride) on the surface of the GNSs (S-GNSs), restacking and aggregation of the GNSs were efficiently suppressed, which also attracted sulfonate groups from the WPU matrix. Because of the favorable interfacial interactions arising from electrostatic attraction, the S-GNS exhibited good compatibility with the WPU matrix. Such a homogeneous dispersion contributed to the construction of an elec. conductive network. The S-GNS/WPU composite exhibited a low elec. cond. percolation threshold and an outstanding enhanced elec. cond. of ∼5.1 S/m. A high EMI shielding effectiveness of ∼32 dB was obtained by the WPU composites with contents of 5 vol.% (∼7.7%) S-GNSs.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXms1yrtbY%253D&md5=e95ed4ca51031d6e37228551153cc19a
129. 129
  Lee, D. Y.; Khatun, Z.; Lee, J. H.; Lee, Y.; In, I. Blood Compatible Graphene/Heparin Conjugate through Noncovalent Chemistry Biomacromolecules 2011, 12, 336– 341 DOI: 10.1021/bm101031a
  
  129
  Blood Compatible Graphene/Heparin Conjugate through Noncovalent Chemistry
  
  Lee, Da Young; Khatun, Zehedina; Lee, Ji-Hoon; Lee, Yong-kyu; In, Insik
  
  Biomacromolecules (2011), 12 (2), 336-341CODEN: BOMAF6; ISSN:1525-7797. (American Chemical Society)
  
  Blood compatible graphene/heparin conjugate is simply formulated through noncovalent interaction between chem. reduced graphene and heparin. Charge repulsion of neg. charged heparin on graphene plates renders hydrophobic graphene to be solubilized in aq. media without any pptn. or aggregation even after 6 mo. Unfractioned heparin (UFH) with higher mol. wt. was effective for graphene solubilization while low mol. wt. heparin (LMWH) was not. Noncovalently interacting heparin chains on graphene plates preserve their anticoagulant activity after conjugation with graphene. Graphene/UFH conjugate shows much enhanced anti-factor Xa (FXa) activity of 29.6 IU/mL compared with pristine graphene oxide (GO; 1.03 IU/mL).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXivFCgsg%253D%253D&md5=ae867232818507bdef95a8d8acd2454f
130. 130
  Zhang, Y.; Zhang, J.; Huang, X.; Zhou, X.; Wu, H.; Guo, S. Assembly of Graphene Oxide–Enzyme Conjugates through Hydrophobic Interaction Small 2012, 8, 154– 159 DOI: 10.1002/smll.201101695
  
  There is no corresponding record for this reference.
131. 131
  Zhang, J.; Zhang, F.; Yang, H.; Huang, X.; Liu, H.; Zhang, J.; Guo, S. Graphene Oxide as a Matrix for Enzyme Immobilization Langmuir 2010, 26, 6083– 6085 DOI: 10.1021/la904014z
  
  131
  Graphene Oxide as a Matrix for Enzyme Immobilization
  
  Zhang, Jiali; Zhang, Feng; Yang, Haijun; Huang, Xuelei; Liu, Hui; Zhang, Jingyan; Guo, Shouwu
  
  Langmuir (2010), 26 (9), 6083-6085CODEN: LANGD5; ISSN:0743-7463. (American Chemical Society)
  
  Graphene oxide (GO), having a large sp. surface area and abundant functional groups, provides an ideal substrate for study enzyme immobilization. We demonstrated that the enzyme immobilization on the GO sheets could take place readily without using any crosslinking reagents and addnl. surface modification. The atomically flat surface enabled us to observe the immobilized enzyme in the native state directly using at. force microscopy (AFM). Combining the AFM imaging results of the immobilized enzyme mols. and their catalytic activity, we illustrated that the conformation of the immobilized enzyme is mainly detd. by interactions of enzyme mols. with the functional groups of GO.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXjsFOmtLg%253D&md5=f93bfbcbfbed2d52c0b582aba257157c
132. 132
  Alwarappan, S.; Boyapalle, S.; Kumar, A.; Li, C. Z.; Mohapatra, S. Comparative Study of Single-, Few-, and Multilayered Graphene toward Enzyme Conjugation and Electrochemical Response J. Phys. Chem. C 2012, 116, 6556– 6559 DOI: 10.1021/jp211201b
  
  132
  Comparative Study of Single-, Few-, and Multilayered Graphene toward Enzyme Conjugation and Electrochemical Response
  
  Alwarappan, Subbiah; Boyapalle, Sandhya; Kumar, Ashok; Li, Chen-Zhong; Mohapatra, Shyam
  
  Journal of Physical Chemistry C (2012), 116 (11), 6556-6559CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
  
  Graphene, with its exceptional mech., thermal, elec., optical, and electronic properties may exist as single-, few-, or multilayered thin sheets. Though the no. of layers may affect cond., its role toward enzyme immobilization and enzymic biosensing applications is unknown. Herein, the authors report the electrochem. performance of electrodes of graphene comprising varying layers immobilized with the enzyme glucose oxidase for the detection of the model analyte glucose. It is interesting to note that these different-layered graphene exhibit an identical electrochem. performance and sensitivity toward the detection of glucose. In addn., all of these electrodes exhibited a similar percentage of electrode fouling after 60 cycles. Following this, the authors have then calcd. the amt. of enzyme bound to the electrode surface. Results indicated that single-, few-, and multilayered graphene electrodes immobilize a similar amt. of glucose oxidase. Thus, together, these results demonstrate that the no. of layers stacked within the graphene structure have no significant role in the enzyme conjugation and subsequent electrochem. response during the electroanal.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XislSku70%253D&md5=e7daeecd7ead279482ed370499d81d31
133. 133
  Heien, M. L. A. V.; Khan, A. S.; Ariansen, J. L.; Cheer, J. F.; Phillips, P. E. M.; Wassum, K. M.; Wightman, R. M. Proc. Natl. Acad. Sci. U. S. A. 2005, 102, 10023– 10028 DOI: 10.1073/pnas.0504657102
  
  There is no corresponding record for this reference.
134. 134
  Wang, Y.; Li, Y.; Tang, L.; Lu, J.; Li, J. Application of Graphene-Modified Electrode for Selective Detection of Dopamine Electrochem. Commun. 2009, 11, 889– 892 DOI: 10.1016/j.elecom.2009.02.013
  
  134
  Application of graphene-modified electrode for selective detection of dopamine
  
  Wang, Ying; Li, Yueming; Tang, Longhua; Lu, Jin; Li, Jinghong
  
  Electrochemistry Communications (2009), 11 (4), 889-892CODEN: ECCMF9; ISSN:1388-2481. (Elsevier B.V.)
  
  Graphene was prepd. chem. by Hummers and Offeman method and the graphene-modified electrode was applied in selective detn. of dopamine with a linear range from 5 μM to 200 μM in a large excess of ascorbic acid. Selective detection was realized in completely eliminating ascorbic acid, different from the methods based on the potential sepns. π-π stacking interaction between dopamine and graphene surface may accelerate the electron transfer whereas weaken the ascorbic acid oxidn. on this graphene-modified electrode. The resulting graphene-modified electrode also showed a better performance than multi-walled carbon nanotubes-modified electrode. The phenomena were considered from the elusive 2D structure and unique electronic properties of graphene.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXjslOjt7w%253D&md5=264faf18d4e83345ac277ca694b34420
135. 135
  Kim, Y. R.; Bong, S.; Kang, Y. J.; Yang, Y.; Mahajan, R. K.; Kim, J. S.; Kim, H. Electrochemical Detection of Dopamine in the Presence of Ascorbic Acid Using Graphene Modified Electrodes Biosens. Bioelectron. 2010, 25, 2366– 2369 DOI: 10.1016/j.bios.2010.02.031
  
  135
  Electrochemical detection of dopamine in the presence of ascorbic acid using graphene modified electrodes
  
  Kim, Yang-Rae; Bong, Sungyool; Kang, Yeon-Joo; Yang, Yongtak; Mahajan, Rakesh Kumar; Kim, Jong Seung; Kim, Hasuck
  
  Biosensors & Bioelectronics (2010), 25 (10), 2366-2369CODEN: BBIOE4; ISSN:0956-5663. (Elsevier B.V.)
  
  Dopamine plays a significant role in the function of human metab. It is important to develop sensitive sensor for the detn. of dopamine without the interference by ascorbic acid. This paper reports the synthesis of graphene using a modified Hummer's method and its application for the electrochem. detection of dopamine. Electrochem. measurements were performed at glassy carbon electrode modified with graphene via drop-casting method. Cyclic voltammogram of ferri/ferrocyanide redox couple at graphene modified electrode showed an increased current intensity compared with glassy carbon electrode and graphite modified electrode. The decrease of charge transfer resistance was also analyzed by electrochem. impedance spectroscopy. The capacity of graphene modified electrode for selective detection of dopamine was confirmed in a sufficient amt. of ascorbic acid (1 mM). The obsd. linear range for the detn. of dopamine concn. was from 4 μM to 100 μM. The detection limit was estd. to be 2.64 μM.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXlvVegsLs%253D&md5=8acab5590c9a2aa383c1ed9c81f1078d
136. 136
  Lian, Q.; He, Z.; He, Q.; Luo, A.; Yan, K.; Zhang, D.; Lu, X.; Zhou, X. Simultaneous Determination of Ascorbic Acid, Dopamine and Uric Acid Based on Tryptophan Functionalized Graphene Anal. Chim. Acta 2014, 823, 32– 39 DOI: 10.1016/j.aca.2014.03.032
  
  136
  Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene
  
  Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia; Lu, Xiaoquan; Zhou, Xibin
  
  Analytica Chimica Acta (2014), 823 (), 32-39CODEN: ACACAM; ISSN:0003-2670. (Elsevier B.V.)
  
  A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π-π conjugate action between graphene (GR) and tryptophan (Trp) mol. The material as prepd. had well dispersivity in water and better cond. than pure GR. The surface morphol. of Trp-GR was characterized by SEM (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochem. behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The sepn. of the oxidn. peak potentials for AA-DA, DA-UA and UA-AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously detg. AA, DA, and UA. Differential pulse voltammetry (DPV) was used for the detn. of AA, DA, and UA in their mixt. Under optimum conditions, the linear response ranges for the detn. of AA, DA, and UA were 0.2-12.9 mM, 0.5-110 μM, and 10-1000 μM, with the detection limits (S/N = 3) of 10.09 μM, 0.29 μM and 1.24 μM, resp. Furthermore, the modified electrode was investigated for real sample anal.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXls1ajs7g%253D&md5=e85ea000729d4f168858940f94931c78
137. 137
  Zhang, W.; Chai, Y.; Yuan, R.; Chen, S.; Han, J.; Yuan, D. Facile Synthesis of Graphene Hybrid Tube-Like Structure for Simultaneous Detection of Ascorbic Acid, Dopamine, Uric Acid and Tryptophan Anal. Chim. Acta 2012, 756, 7– 12 DOI: 10.1016/j.aca.2012.10.044
  
  There is no corresponding record for this reference.
138. 138
  Lv, M.; Mei, T.; Zhang, C.; Wang, X. Selective and Sensitive Electrochemical Detection of Dopamine Based on Water-Soluble Porphyrin Functionalized Graphene Nanocomposites RSC Adv. 2014, 4, 9261– 9270 DOI: 10.1039/c3ra47234e
  
  138
  Selective and sensitive electrochemical detection of dopamine based on water-soluble porphyrin functionalized graphene nanocomposites
  
  Lv, Meijiao; Mei, Tao; Zhang, Chang'an; Wang, Xianbao
  
  RSC Advances (2014), 4 (18), 9261-9270CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  A biosensor, based on a water-sol. porphyrin-reduced graphene oxide (RGO) nanocomposite synthesized by simultaneous covalent and non-covalent strategies through arom. π-π stacking and the formation of chem. bonds, was prepd. for selective and sensitive detection of dopamine (DA). Compared with graphene or porphyrin alone, porphyrin-RGO nanocomposites exhibited unique advantages for the detection of DA in the presence of interfering substances such as uric acid (UA) and ascorbic acid (AA). The cyclic voltammetry (CV) curves indicated that the porphyrin-RGO modified glassy carbon electrode (GCE) had larger active area and better electrochem. catalytic activity which could attribute to the π-π stacking and the electrostatic attraction between pos. charged DA and neg. charged porphyrin-RGO, which can accelerate the electron transfer and weaken the oxidn. of AA/UA on the porphyrin-RGO/GCE. Differential pulse voltammetry (DPV) was used for the quant. detection of DA. The peak currents increased linearly with the increasing concn. of DA in the range of 1 × 10-6 to 7 × 10-5 M, and the limit of detection (LOD) (S/N = 3) was estd. to be 9.45 × 10-9 M. More importantly, the biosensor exhibited good stability and reproducibility, and would provide a superior platform in the biol. anal.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1yjs7s%253D&md5=966b92b539a79a90c23ff365be7bc5b5
139. 139
  Zhang, Y.; Xia, Z.; Liu, H.; Yang, M.; Lin, L.; Li, Q. Hemin Graphene Oxide-Pristine Carbon Nanotubes Complexes with Intrinsic Peroxidase-Like Activity for the Detection of H₂O₂ and Simultaneous Determination for Trp, AA, DA, and UA Sens. Actuators, B 2013, 188, 496– 501 DOI: 10.1016/j.snb.2013.07.010
  
  139
  Hemin-graphene oxide-pristine carbon nanotubes complexes with intrinsic peroxidase-like activity for the detection of H2O2 and simultaneous determination for Trp, AA, DA, and UA
  
  Zhang, Yu; Xia, Zhi; Liu, Hong; Yang, Mingjian; Lin, Longli; Li, Qianzhu
  
  Sensors and Actuators, B: Chemical (2013), 188 (), 496-501CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)
  
  This paper demonstrated a simple wet-chem. strategy for synthesizing hemin-graphene oxide-pristine carbon nanotubes complexes (H-GO-CNTs) through the π-π interactions, and it was used to construct a novel dual sensor for the detn. of H2O2 and the simultaneous detn. of ascorbic acid (AA), dopamine (DA), uric acid (UA), and tryptophan (Trp). This sensor possesses the advantages of both hemin and GO-CNTs and exhibits several interesting properties. First, hemin has excellent catalysis and intrinsic peroxidase-like activity that can facilitate the catalytic redn. of H2O2. Second, GO can absorb the CNTs through the π-stacking interaction, thus causing pristine CNTs to stably disperse in aq. media. Third, one-dimensional CNTs (1D) combined with 2D GO to form a 3D nanohybrid. This porous structure on the surface of the electrode can facilitate the discrimination of many species which oxidize or reduce at similar potentials. Cyclic voltammetry (CV), SEM (SEM), transmission electron microscopy (TEM) and different pulse voltammetry (DPV) were employed to characterize the sensor. It exhibits good anal. performance, acceptable stability and good selectivity.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs1Sgt7jL&md5=4b1588ab00e12dbb6f094dac9f32c6eb
140. 140
  Pandikumar, A.; Thien Soon How, G.; See, T. P.; Omar, F. S.; Jayabal, S.; Zangeneh Kamali, K.; Yusoff, N.; Jamil, A.; Ramaraj, R.; Abraham John, S. Graphene and Its Nanocomposite Material Based Electrochemical Sensor Platform for Dopamine RSC Adv. 2014, 4, 63296– 63323 DOI: 10.1039/C4RA13777A
  
  140
  Graphene and its nanocomposite material based electrochemical sensor platform for dopamine
  
  Pandikumar, Alagarsamy; Soon How, Gregory Thien; See, Teo Peik; Omar, Fatin Saiha; Jayabal, Subramaniam; Kamali, Khosro Zangeneh; Yusoff, Norazriena; Jamil, Asilah; Ramaraj, Ramasamy; John, Swamidoss Abraham; Lim, Hong Ngee; Huang, Nay Ming
  
  RSC Advances (2014), 4 (108), 63296-63323CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  A review. Dopamine (DA) is an important catecholamine neurotransmitter in the mammalian central nervous system that influences several physiol. functions. The impact of DA levels within the human body significantly affects the body functions. Maintaining DA level is essential and the electrochem. detection methods are often used to detect the DA level to regulate the body function. In this review, graphene (functionalized graphene and N-doped graphene) and its composites (metal, metal oxide, polymer, carbonaceous materials, clay, zeolite, and metal-org. framework based graphene composites) modified electrodes with their improved sensing performance towards DA along with several interfering species are described. Further, recent developments on the fabrication of various graphene based composite modified electrodes are also presented. Some important strategies to improve the selectivity and sensitivity towards DA with graphene based composite modified electrodes are also described.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvV2gtb%252FE&md5=a091dd571052f26a6534e810cf542f51
141. 141
  Min, S. K.; Kim, W. Y.; Cho, Y.; Kim, K. S. Fast DNA Sequencing with a Graphene-Based Nanochannel Device Nat. Nanotechnol. 2011, 6, 162– 165 DOI: 10.1038/nnano.2010.283
  
  141
  Fast DNA sequencing with a graphene-based nanochannel device
  
  Min, Seung Kyu; Kim, Woo Youn; Cho, Yeonchoo; Kim, Kwang S.
  
  Nature Nanotechnology (2011), 6 (3), 162-165CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
  
  Devices in which a single strand of DNA is threaded through a nanopore could be used to efficiently sequence DNA. However, various issues will have to be resolved to make this approach practical, including controlling the DNA translocation rate, suppressing stochastic nucleobase motions, and resolving the signal overlap between different nucleobases. Here, we demonstrate theor. the feasibility of DNA sequencing using a fluidic nanochannel functionalized with a graphene nanoribbon. This approach involves deciphering the changes that occur in the conductance of the nanoribbon as a result of its interactions with the nucleobases via π-π stacking. We show that as a DNA strand passes through the nanochannel, the distinct conductance characteristics of the nanoribbon (calcd. using a method based on d. functional theory coupled to non-equil. Green function theory18-20) allow the different nucleobases to be distinguished using a data-mining technique and a two-dimensional transient autocorrelation anal. This fast and reliable DNA sequencing device should be exptl. feasible in the near future.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXislCjsrw%253D&md5=7db4daac71c95292aa972cd29b6e6c8d
142. 142
  Zhu, C.; Du, D.; Lin, Y. Graphene and Graphene-Like 2D Materials for Optical Biosensing and Bioimaging: A Review 2D Mater. 2015, 2, 032004 DOI: 10.1088/2053-1583/2/3/032004
  
  142
  Graphene and graphene-like 2D materials for optical biosensing and bioimaging: a review
  
  Zhu, Chengzhou; Du, Dan; Lin, Yuehe
  
  2D Materials (2015), 2 (3), 032004/1-032004/17CODEN: DMATB7; ISSN:2053-1583. (IOP Publishing Ltd.)
  
  The increasing demands of bioassay and biomedical applications have significantly promoted the rational design and fabrication of a wide range of functional nanomaterials. Coupling these advanced nanomaterials with biomol. recognition events leads to novel sensing and diagnostic platforms. Because of their unique structures and multifunctionalities, two-dimensional nanomaterials, such as graphene and graphene-like materials (e.g., graphitic carbon nitride, transition metal dichalcogenides, boron nitride, and transition metal oxides), have stimulated great interest in the field of optical biosensors and imaging because of their innovative mech., physicochem. and optical properties. Depending on the different applications, the graphene and graphene-like nanomaterials can be tailored to form either fluorescent emitters or efficient fluorescence quenchers, making them powerful platforms for fabricating a series of optical biosensors to sensitively detect various targets including ions, small biomols.,DNA/RNAand proteins. This review highlights the recent progress in optical biosensors based on graphene and graphene-like 2D materials and their imaging applications. Finally, the opportunities and some crit. challenges in this field are also addressed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXkslWkur4%253D&md5=e4fe32a7675e66a20d7ca806be903895
143. 143
  Liu, Y.; Dong, X.; Chen, P. Biological and Chemical Sensors Based on Graphene Materials Chem. Soc. Rev. 2012, 41, 2283– 2307 DOI: 10.1039/C1CS15270J
  
  143
  Biological and chemical sensors based on graphene materials
  
  Liu, Yuxin; Dong, Xiaochen; Chen, Peng
  
  Chemical Society Reviews (2012), 41 (6), 2283-2307CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)
  
  A review. Owing to their extraordinary elec., chem., optical, mech. and structural properties, graphene and its derivs. have stimulated exploding interests in their sensor applications ever since the 1st isolation of free-standing graphene sheets in year 2004. This article critically and comprehensively reviews the emerging graphene-based electrochem. sensors, electronic sensors, optical sensors, and nanopore sensors for biol. or chem. detection. The authors emphasize on the underlying detection (or signal transduction) mechanisms, the unique roles and advantages of the used graphene materials. Properties and prepns. of different graphene materials, their functionalizations are also comparatively discussed in view of sensor development. Finally, the perspective and current challenges of graphene sensors are outlined (312 refs.).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XivFWlsLo%253D&md5=5454d4561e7ab73b83c94265bc2b3d70
144. 144
  Green, N. S.; Norton, M. L. Interactions of DNA with graphene and sensing applications of graphene field-effect transistor devices: A review Anal. Chim. Acta 2015, 853, 127– 142 DOI: 10.1016/j.aca.2014.10.023
  
  144
  Interactions of DNA with graphene and sensing applications of graphene field-effect transistor devices: A review
  
  Green, Nathaniel S.; Norton, Michael L.
  
  Analytica Chimica Acta (2015), 853 (), 127-142CODEN: ACACAM; ISSN:0003-2670. (Elsevier B.V.)
  
  A review. Graphene field-effect transistors (GFET) have emerged as powerful detection platforms enabled by the advent of chem. vapor deposition (CVD) prodn. of the unique atomically thin 2D material on a large scale. DNA aptamers, short target-specific oligonucleotides, are excellent sensor moieties for GFETs due to their strong affinity to graphene, relatively short chain-length, selectivity, and a high degree of analyte variability. However, the interaction between DNA and graphene is not fully understood, leading to questions about the structure of surface-bound DNA, including the morphol. of DNA nanostructures and the nature of the electronic response seen from analyte binding. This review critically evaluates recent insights into the nature of the DNA graphene interaction and its affect on sensor viability for DNA, small mols., and proteins with respect to previously established sensing methods. We first discuss the sorption of DNA to graphene to introduce the interactions and forces acting in DNA based GFET devices and how these forces can potentially affect the performance of increasingly popular DNA aptamers and even future DNA nanostructures as sensor substrates. Next, we discuss the novel use of GFETs to detect DNA and the underlying electronic phenomena that are typically used as benchmarks for characterizing the analyte response of these devices. Finally, we address the use of DNA aptamers to increase the selectivity of GFET sensors for small mols. and proteins and compare them with other, state of the art, detection methods.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslOrtbbI&md5=a25aa3f596797cc4de596e54f6cc3c3c
145. 145
  Lu, C. H.; Yang, H. H.; Zhu, C. L.; Chen, X.; Chen, G. N. A Graphene Platform for Sensing Biomolecules Angew. Chem., Int. Ed. 2009, 48, 4785– 4787 DOI: 10.1002/anie.200901479
  
  145
  A Graphene Platform for Sensing Biomolecules
  
  Lu, Chun-Hua; Yang, Huang-Hao; Zhu, Chun-Ling; Chen, Xi; Chen, Guo-Nan
  
  Angewandte Chemie, International Edition (2009), 48 (26), 4785-4787CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  The use of graphene oxide (GO) as a platform for the sensitive and selective detection of DNA and proteins is presented. The interaction of GO and dye-labeled single-stranded DNA leads to quenching of the dye fluorescence. Conversely, the presence of a target DNA or protein leads to the binding of the dye-labeled DNA and target, releasing the DNA from GO, thereby restoring the dye fluorescence.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXntlOitb4%253D&md5=60952d44796a7b63706a2225a19f4729
146. 146
  Bonanni, A.; Pumera, M. Graphene Platform for Hairpin-DNA Based Impedimetric Genosensing ACS Nano 2011, 5, 2356– 2361 DOI: 10.1021/nn200091p
  
  There is no corresponding record for this reference.
147. 147
  Loo, A. H.; Bonanni, A.; Pumera, M. An Insight into the Hybridization Mechanism of Hairpin DNA Physically Immobilized on Chemically Modified Graphenes Analyst 2013, 138, 467– 471 DOI: 10.1039/C2AN36199J
  
  There is no corresponding record for this reference.
148. 148
  Giovanni, M.; Bonanni, A.; Pumera, M. Detection of DNA Hybridization on Chemically Modified Graphene Platforms Analyst 2012, 137, 580– 583 DOI: 10.1039/C1AN15910K
  
  There is no corresponding record for this reference.
149. 149
  Loo, A. H.; Bonanni, A.; Ambrosi, A.; Poh, H. L.; Pumera, M. Impedimetric Immunoglobulin G Immunosensor Based on Chemically Modified Graphenes Nanoscale 2012, 4, 921– 925 DOI: 10.1039/C2NR11492E
  
  149
  Impedimetric immunoglobulin G immunosensor based on chemically modified graphenes
  
  Loo, Adeline Huiling; Bonanni, Alessandra; Ambrosi, Adriano; Poh, Hwee Ling; Pumera, Martin
  
  Nanoscale (2012), 4 (3), 921-925CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  Immunosensors which display high sensitivity and selectivity are of utmost importance to the biomedical field. Graphene is a material which has immense potential for the fabrication of immunosensors. For the first time, we evaluate the immunosensing capabilities of various graphene surfaces in this work. We propose a simple and label-free electrochem. impedimetric immunosensor for IgG (IgG) based on chem. modified graphene (CMG) surfaces such as graphite oxide, graphene oxide, thermally reduced graphene oxide and electrochem. reduced graphene oxide. Disposable electrochem. printed electrodes were first modified with CMG materials before anti-IgG (anti-IgG), which is specific to IgG, was immobilized. The principle of detection lies in the changes in impedance spectra of the redox probe after the attachment of IgG to the immobilized anti-IgG. It was found that thermally reduced graphene oxide has the best performance when compared to the other CMG materials. In addn., the optimal concn. of anti-IgG to be deposited onto the modified electrode surface is 10 μg ml-1 and the linear range of detection of the immunosensor is from 0.3 μg ml-1 to 7 μg ml-1. Finally, the fabricated immunosensor also displays selectivity for IgG.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xps1ekuw%253D%253D&md5=12d9e97699f387a5f943405a5f682946
150. 150
  Bonanni, A.; Chua, C. K.; Zhao, G.; Sofer, Z.; Pumera, M. Inherently Electroactive Graphene Oxide Nanoplatelets As Labels for Single Nucleotide Polymorphism Detection ACS Nano 2012, 6, 8546– 8551 DOI: 10.1021/nn301359y
  
  150
  Inherently electroactive graphene oxide nanoplatelets as labels for single nucleotide polymorphism detection
  
  Bonanni, Alessandra; Chua, Chun Kiang; Zhao, Guanjia; Sofer, Zdenek; Pumera, Martin
  
  ACS Nano (2012), 6 (10), 8546-8551CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Graphene materials are being widely used in electrochem. due to their versatility and excellent properties as platforms for biosensing. However, no records show the use of inherent redox properties of graphene oxide as a label for detection. Here for the first time we used graphene oxide nanoplatelets (GONPs) as electroactive labels for DNA anal. The working signal comes from the redn. of the oxygen-contg. groups present on the surface of GONPs. The different ability of the graphene oxide nanoplatelets to conjugate to DNA hybrids obtained with complementary, noncomplementary, and one-mismatch sequences allows the discrimination of single-nucleotide polymorphism correlated with Alzheimer's disease. We believe that our findings are very important to open a new route in the use of graphene oxide in electrochem.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtlOjt7jJ&md5=570ca1bd0a49cfd57af4cda8fe5b4363
151. 151
  Goedert, M.; Spillantini, M. G. A Century of Alzheimer’s Disease Science 2006, 314, 777– 781 DOI: 10.1126/science.1132814
  
  151
  A Century of Alzheimer's Disease
  
  Goedert, Michel; Spillantini, Maria Grazia
  
  Science (Washington, DC, United States) (2006), 314 (5800), 777-781CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  A review. One hundred years ago a small group of psychiatrists described the abnormal protein deposits in the brain that define the most common neurodegenerative diseases. Over the past 25 years, it has become clear that the proteins forming the deposits are central to the disease process. Amyloid-β and tau make up the plaques and tangles of Alzheimer's disease, where these normally sol. proteins assemble into amyloid-like filaments. Tau inclusions are also found in a no. of related disorders. Genetic studies have shown that dysfunction of amyloid-β or tau is sufficient to cause dementia. The ongoing mol. dissection of the neurodegenerative pathways is expected to lead to a true understanding of disease pathogenesis.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XhtFKit73K&md5=6e152685c65d4a08e0b23c0807a35149
152. 152
  Li, Q.; Liu, L.; Zhang, S.; Xu, M.; Wang, X.; Wang, C.; Besenbacher, F.; Dong, M. Modulating Aβ_33–42 Peptide Assembly by Graphene Oxide Chem. - Eur. J. 2014, 20, 7236– 7240 DOI: 10.1002/chem.201402022
  
  152
  Modulating Aβ33-42 Peptide Assembly by Graphene Oxide
  
  Li, Qiang; Liu, Lei; Zhang, Shuai; Xu, Meng; Wang, Xueqin; Wang, Chen; Besenbacher, Flemming; Dong, Mingdong
  
  Chemistry - A European Journal (2014), 20 (24), 7236-7240CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Graphene oxide (GO) is utilized as the modulator to tune the formation and development of amyloid fibrils (Aβ33-42). Atomic force microscopy temporal evolution measurements reveal that the initial binding between the peptide monomer and the large available surface of the GO sheets can redirect the assembly pathway of amyloid beta. The results support the possibility to develop graphene-based materials to inhibit amyloidosis.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXotV2nsbk%253D&md5=8856344493b93747363a3196941aac09
153. 153
  Mahmoudi, M.; Akhavan, O.; Ghavami, M.; Rezaee, F.; Ghiasi, S. M. A. Graphene Oxide Strongly Inhibits Amyloid Beta Fibrillation Nanoscale 2012, 4, 7322– 7325 DOI: 10.1039/c2nr31657a
  
  153
  Graphene oxide strongly inhibits amyloid beta fibrillation
  
  Mahmoudi, Morteza; Akhavan, Omid; Ghavami, Mahdi; Rezaee, Farhad; Ghiasi, Seyyed Mohammad Amin
  
  Nanoscale (2012), 4 (23), 7322-7325CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  Since amyloid beta fibrillation (AβF) plays an important role in the development of neurodegenerative diseases, the authors investigated the effect of graphene oxide (GO) and their protein-coated surfaces on the kinetics of Aβ fibrillation in the aq. soln. The authors showed that GO and their protein-covered surfaces delay the AβF process via adsorption of amyloid monomers. Also, the large available surface of GO sheets can delay the AβF process by adsorption of amyloid monomers. The inhibitory effect of the GO sheet was increased when the authors increase the concn. from 10% (in vitro; stimulated media) to 100% (in vivo; stimulated media). The authors' results revealed that GO and their surface proteins inhibit AβF by decreasing the kinetic reaction.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhvVSmsL3K&md5=427a27a8b3cd7fc0c32f33254d2bc49c
154. 154
  Wang, J.; Cao, Y.; Li, Q.; Liu, L.; Dong, M. Size Effect of Graphene Oxide on Modulating Amyloid Peptide Assembly Chem. - Eur. J. 2015, 21, 9632– 9637 DOI: 10.1002/chem.201500577
  
  154
  Size effect of graphene oxide on modulating amyloid peptide assembly
  
  Wang, Jie; Cao, Yunpeng; Li, Qiang; Liu, Lei; Dong, Mingdong
  
  Chemistry - A European Journal (2015), 21 (27), 9632-9637CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Protein misfolding and abnormal assembly could lead to aggregates such as oligomer, proto-fibril, mature fibril, and senior amyloid plaques, which are assocd. with the pathogenesis of many amyloid diseases. These irreversible amyloid aggregates typically form in vivo and researchers have been endeavoring to find new modulators to invert the aggregation propensity in vitro, which could increase understanding in the mechanism of the aggregation of amyloid protein and pave the way to potential clin. treatment. Graphene oxide (GO) was shown to be a good modulator, which could strongly control the amyloidosis of Aβ(33-42). In particular, quartz crystal microbalance (QCM), CD spectroscopy, and at. force microscopy (AFM) measurements revealed the size-dependent manner of GO on modulating the assembly of amyloid peptides, which could be a possible way to regulate the self-assembled nanostructure of an amyloid peptide in a predictable manner.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXpt1aqurg%253D&md5=ded3d60518f42c3025755bc393cdcfcc
155. 155
  Wahid, M. H.; Stroeher, U. H.; Eroglu, E.; Chen, X.; Vimalanathan, K.; Raston, C. L.; Boulos, R. A. Aqueous Based Synthesis of Antimicrobial-Decorated Graphene J. Colloid Interface Sci. 2015, 443, 88– 96 DOI: 10.1016/j.jcis.2014.11.043
  
  There is no corresponding record for this reference.
156. 156
  Zhou, L.; Jiang, H.; Wei, S.; Ge, X.; Zhou, J.; Shen, J. High-Efficiency Loading of Hypocrellin B on Graphene Oxide for Photodynamic Therapy Carbon 2012, 50, 5594– 5604 DOI: 10.1016/j.carbon.2012.08.013
  
  156
  High-efficiency loading of hypocrellin B on graphene oxide for photodynamic therapy
  
  Zhou, Lin; Jiang, Huijun; Wei, Shaohua; Ge, Xuefeng; Zhou, Jiahong; Shen, Jian
  
  Carbon (2012), 50 (15), 5594-5604CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  A novel hybrid of graphene oxide (GO) and hypocrellin B (HB) was prepd. using a simple noncovalent method. An efficient loading of HB on GO as high as 2 mg/mg was obtained. Mechanism anal. indicated that the π-π stacking interaction is the dominant driving force in the noncovalent interaction between HB and GO. Irradn. of HB and GO hybrid (HB-GO) results in efficient generation of singlet oxygen (1O2). In vitro studies have demonstrated the active uptake of HB-GO into the cytosol of tumor cells. Significant damage to such impregnated tumor cells was obsd. upon irradn.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1Onu7vK&md5=ce22940a0d0a18e7cef3edb6d540f49a
157. 157
  Chowdhury, S. M.; Surhland, C.; Sanchez, Z.; Chaudhary, P.; Kumar, M. A. S.; Lee, S.; Peña, L. A.; Waring, M.; Sitharaman, B.; Naidu, M. Graphene Nanoribbons as a Drug Delivery Agent for Lucanthone Mediated Therapy of Glioblastoma Multiforme Nanomedicine 2015, 11, 109– 118 DOI: 10.1016/j.nano.2014.08.001
  
  157
  Graphene nanoribbons as a drug delivery agent for lucanthone mediated therapy of glioblastoma multiforme
  
  Chowdhury, Sayan Mullick; Surhland, Cassandra; Sanchez, Zina; Chaudhary, Pankaj; Suresh Kumar, M. A.; Lee, Stephen; Pena, Louis A.; Waring, Michael; Sitharaman, Balaji; Naidu, Mamta
  
  Nanomedicine (New York, NY, United States) (2015), 11 (1), 109-118CODEN: NANOBF; ISSN:1549-9634. (Elsevier)
  
  PEG-DSPE coated oxidized graphene nanoribbons (O-GNR-PEG-DSPE) were used as agent for delivery of anti-tumor drug Lucanthone (Luc) into Glioblastoma Multiformae (GBM) cells targeting base excision repair enzyme APE-1 (Apurinic endonuclease-1). Lucanthone, an endonuclease inhibitor of APE-1, was loaded onto O-GNR-PEG-DSPEs using a simple non-covalent method. We found its uptake by GBM cell line U251 exceeding 67% and 60% in APE-1-overexpressing U251, post 24 h. However, their uptake was ∼ 38% and 29% by MCF-7 and rat glial progenitor cells (CG-4), resp. TEM anal. of U251 showed large aggregates of O-GNR-PEG-DSPE in vesicles. Luc-O-GNR-PEG-DSPE was significantly toxic to U251 but showed little/no toxicity when exposed to MCF-7/CG-4 cells. This differential uptake effect can be exploited to use O-GNR-PEG-DSPEs as a vehicle for Luc delivery to GBM, while reducing nonspecific cytotoxicity to the surrounding healthy tissue. Cell death in U251 was necrotic, probably due to oxidative degrdn. of APE-1.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVGnsrzJ&md5=6ce714ccb1d173932ed487e13cb0285e
158. 158
  Rahmanian, N.; Hamishehkar, H.; Dolatabadid, J. E. N.; Arsalani, N. Nano Graphene Oxide: A Novel Carrier for Oral Delivery of Flavonoids Colloids Surf., B 2014, 123, 331– 338 DOI: 10.1016/j.colsurfb.2014.09.036
  
  There is no corresponding record for this reference.
159. 159
  Liu, Z.; Robinson, J. T.; Sun, X.; Dai, H. PEGylated Nanographene Oxide for Delivery of Water-Insoluble Cancer Drugs J. Am. Chem. Soc. 2008, 130, 10876– 10877 DOI: 10.1021/ja803688x
  
  159
  PEGylated nanographene oxide for delivery of water-insoluble cancer drugs
  
  Liu, Zhuang; Robinson, Joshua T.; Sun, Xiaoming; Dai, Hongjie
  
  Journal of the American Chemical Society (2008), 130 (33), 10876-10877CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  It is known that many potent, often arom. drugs are water insol., which has hampered their use for disease treatment. In this work, we functionalized nanographene oxide (NGO), a novel graphitic material, with branched polyethylene glycol (PEG) to obtain a biocompatible NGO-PEG conjugate stable in various biol. solns., and used them for attaching hydrophobic arom. mols. including a camptothecin (CPT) analog, SN38, noncovalently via π-π stacking. The resulting NGO-PEG-SN38 complex exhibited excellent water soly. while maintaining its high cancer cell killing potency similar to that of the free SN38 mols. in org. solvents. The efficacy of NGO-PEG-SN38 was far higher than that of irinotecan (CPT-11), a FDA-approved water sol. SN38 prodrug used for the treatment of colon cancer. Our results showed that graphene is a novel class of material promising for biol. applications including future in vivo cancer treatment with various arom., low-soly. drugs.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXptVCqu78%253D&md5=6e96b6929256966ec9ca88aca0805f8b
160. 160
  Georgakilas, V.; Kouloumpis, A.; Gournis, D.; Bourlinos, A.; Trapalis, C.; Zboril, R. Tuning the Dispersibility of Carbon Nanostructures from Organophilic to Hydrophilic: Towards the Preparation of New Multipurpose Carbon-Based Hybrids Chem. - Eur. J. 2013, 19, 12884– 12891 DOI: 10.1002/chem.201301200
  
  160
  Tuning the Dispersibility of Carbon Nanostructures from Organophilic to Hydrophilic: towards the Preparation of New Multipurpose Carbon-Based Hybrids
  
  Georgakilas, Vasilios; Kouloumpis, Antonios; Gournis, Dimitrios; Bourlinos, Athanasios; Trapalis, Christos; Zboril, Radek
  
  Chemistry - A European Journal (2013), 19 (38), 12884-12891CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  The hydroxyphenyl derivs. of carbon nanostructures (graphene and carbon nanotubes) can be easily transformed into highly organophilic or hydrophilic derivs. by using the ionic interactions between the phenolic groups and oleylamine or tetramethylammonium hydroxide, resp. The products were finely dispersed in homo-polymers or block co-polymers to create homogeneous carbon-based nanocomposites and were used as nanocarriers for the dispersion and protection of strongly hydrophobic compds., such as large arom. chromophores or anticancer drugs in aq. solns.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht1Crt73P&md5=02890bdb4b5b05e5c7dc6fbc5e202b9c
161. 161
  Balcioglu, M.; Rana, M.; Yigit, M. V. Doxorubicin Loading on Graphene Oxide, Iron Oxide and Gold Nanoparticle Hybrid J. Mater. Chem. B 2013, 1, 6187– 6193 DOI: 10.1039/c3tb20992j
  
  161
  Doxorubicin loading on graphene oxide, iron oxide and gold nanoparticle hybrid
  
  Balcioglu, Mustafa; Rana, Muhit; Yigit, Mehmet V.
  
  Journal of Materials Chemistry B: Materials for Biology and Medicine (2013), 1 (45), 6187-6193CODEN: JMCBDV; ISSN:2050-7518. (Royal Society of Chemistry)
  
  We report the facile and non-covalent construction of a graphene oxide-based functional hybrid material with gold and fluorescently labeled superparamagnetic iron oxide nanoparticles [GO-MNcy5.5-AuNP]. The obtained [GO-MNcy5.5-AuNP] hybrid exhibits the phys. properties of each component. The relaxivity of the magnetic nanoparticles was improved, cy5.5 fluorescence was completely quenched and the surface plasmon peak of the gold nanoparticles at 520 nm was obsd. in the hybrid complex. The hybrid exhibits an ultra-high doxorubicin loading capacity of 6.05 mg mg-1 at 0.32 mg ml-1 drug concn. This material could serve as a promising platform for theranostics, due to its contrast agent compn. and anticancer drug loading capacity.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslWms7zP&md5=da65d34c822999c0664efe9004ae5ec6
162. 162
  Koninti, R. K.; Sengupta, A.; Gavvala, K.; Ballav, N.; Hazra, P. Loading of an Anti-Cancer Drug onto Graphene Oxide and Subsequent Release to DNA/RNA: A Direct Optical Detection Nanoscale 2014, 6, 2937– 2944 DOI: 10.1039/c3nr06081k
  
  There is no corresponding record for this reference.
163. 163
  Chia, J. S. Y.; Tan, M. T. T.; Khiew, P. S.; Chin, J. K.; Siong, C. W. A Bio-Electrochemical Sensing Platform for Glucose Based on Irreversible, Non-Covalent pi–pi Functionalization of Graphene Produced via a Novel, Green Synthesis Method Sens. Actuators, B 2015, 210, 558– 565 DOI: 10.1016/j.snb.2015.01.023
  
  163
  A bio-electrochemical sensing platform for glucose based on irreversible, non-covalent pi-pi functionalization of graphene produced via a novel, green synthesis method
  
  Chia, Joanna Su Yuin; Tan, Michelle T. T.; Khiew, Poi Sim; Chin, Jit Kai; Siong, Chiu Wee
  
  Sensors and Actuators, B: Chemical (2015), 210 (), 558-565CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)
  
  In this work, pristine graphene was produced through a novel single step exfoliation of graphite in mild sonochem. alc.-water treatment. The developed green synthesis approach successfully eradicates issues assocd. with conventional methods which use org. solvents, acids and oxidizers, leaving undesirable functional groups attached to the graphene surface. Results from cyclic voltammetry and amperometric anal. showed a wide linear range up to 5 mM and sensitivity improvements of more than 22 times in comparison to the control sample. Subsequently, an electrochem. glucose biosensor was fabricated by the immobilization of glucose oxidase (GOx) via bi-functional linkers. This reliable surface modification method provides irreversible non-covalent bonding between graphene and the enzymic amide groups, while preserving the sp2 graphene structure, while promoting better electron transfer kinetics between the FAD/FADH2 redox sites of GOx at the modified electrode surface. The fabricated biosensor exhibited satisfactory long-term stability, reproducibility and high selectivity for glucose detection and showed significant improvements when compared to unmodified electrodes.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXht1Ogu7w%253D&md5=465a7b517ebee49162ae027748c75d7f
164. 164
  Kong, N.; Liua, J.; Kong, Q.; Wang, R.; Barrow, C. J.; Yang, W. Graphene Modified Gold Electrode via Stacking Interaction for Analysis of Cu²⁺ and Pb²⁺ Sens. Actuators, B 2013, 178, 426– 433 DOI: 10.1016/j.snb.2013.01.009
  
  164
  Graphene modified gold electrode via π-π stacking interaction for analysis of Cu2+ and Pb2+
  
  Kong, Na; Liu, Jingquan; Kong, Qingshan; Wang, Rui; Barrow, Colin J.; Yang, Wenrong
  
  Sensors and Actuators, B: Chemical (2013), 178 (), 426-433CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)
  
  A gold electrode modified with graphene via non-covalent interaction for a chem. sensor is presented. The gold electrode was first modified with carboxylic acid functionalities, followed by the immobilization of pyrene groups via the esterification reaction. The freshly prepd. graphene nanosheets were then attached on the electrode surface via π-π stacking interaction for the anal. of Cu2+ and Pb2+. The graphene modified gold electrode exhibited enhanced anal. sensitivity toward Cu2+ and Pb2+. The linear detection range for Cu2+ anal. is 1.5-20 nM and Pb2+ is 0.4-20 nM. Good reusability and repeatability were also obsd.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXivFCku78%253D&md5=195d0670a25c56c347596b2aab5102f9
165. 165
  Shen, X.; Liu, Y.; Pang, Y.; Yao, W. Conjugation of Graphene on Au Surface by π–π Interaction and Click Chemistry Electrochem. Commun. 2013, 30, 13– 16 DOI: 10.1016/j.elecom.2013.01.025
  
  There is no corresponding record for this reference.
166. 166
  Zhang, S.; Tang, S.; Lei, J.; Dong, H.; Ju, H. Functionalization of Graphene Nanoribbons with Porphyrin for Electrocatalysis and Amperometric Biosensing J. Electroanal. Chem. 2011, 656, 285– 288 DOI: 10.1016/j.jelechem.2010.10.005
  
  166
  Functionalization of graphene nanoribbons with porphyrin for electrocatalysis and amperometric biosensing
  
  Zhang, Siyuan; Tang, Sheng; Lei, Jianping; Dong, Haifeng; Ju, Huangxian
  
  Journal of Electroanalytical Chemistry (2011), 656 (1-2), 285-288CODEN: JECHES; ISSN:1873-2569. (Elsevier B.V.)
  
  A direct electrochem. method to reduce graphene oxide nanoribbons is proposed. The reduced graphene nanoribbons (RGNRs) could be functionalized with water-sol. Fe(III) meso-tetrakis(N-methylpyridinum-4-yl)porphyrin (FeTMPyP) via π-π noncovalent interaction on electrode surface. The resulting FeTMPyP/RGNRs film showed excellent electrocatalysis toward the redn. of dissolved O at peak potential of -0.28 V Using glucose oxidase as model enzyme, a biosensor based on the consumption of O2 was developed for amperometric detection of glucose ranging from 0.5 mM to 10 mM. This biosensor could be successfully applied in the detection of glucose in human serum. The FeTMPyP functionalized RGNRs provided a platform for electrocatalysis and biosensing of oxidase substrates.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXmtVWqtbg%253D&md5=3a26255e9636475c800bf0309142db79
167. 167
  Srinivasan, S.; Je, S. H.; Back, S.; Barin, G.; Buyukcakir, O.; Guliyev, R.; Jung, Y.; Coskun, A. Ordered Supramolecular Gels Based on Graphene Oxide and Tetracationic Cyclophanes Adv. Mater. 2014, 26, 2725– 2729 DOI: 10.1002/adma.201304334
  
  There is no corresponding record for this reference.
168. 168
  Georgakilas, V.; Perman, J. A.; Tucek, J.; Zboril, R. Broad Family of Carbon Nanoallotropes – Classification, Chemistry and Advanced Architecture of Fullerene, Nanotube, Graphene and their Relatives Chem. Rev. 2015, 115, 4744– 4822 DOI: 10.1021/cr500304f
  
  There is no corresponding record for this reference.
169. 169
  Shao, Q.; Tang, J.; Lin, Y.; Li, J.; Qin, F.; Yuan, J.; Qin, L. C. Carbon Nanotube Spaced Graphene Aerogels with Enhanced Capacitance in Aqueous and Ionic Liquid Electrolytes J. Power Sources 2015, 278, 751– 759 DOI: 10.1016/j.jpowsour.2014.12.052
  
  169
  Carbon nanotube spaced graphene aerogels with enhanced capacitance in aqueous and ionic liquid electrolytes
  
  Shao, Qingguo; Tang, Jie; Lin, Yuexian; Li, Jing; Qin, Faxiang; Yuan, Jinshi; Qin, Lu-Chang
  
  Journal of Power Sources (2015), 278 (), 751-759CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)
  
  Carbon nanotube spaced graphene aerogels have been prepd. by a hydrothermal method and used for supercapacitor applications. The sp. surface area and specific capacitance can be controlled by tuning the amt. of added carbon nanotubes. The as-prepd. composite aerogels retain the advantage of aerogel structure in providing macropores to ensure electrodes fast wetted by the electrolyte ions and also possess addnl. mesopores created by the carbon nanotube spacers for more ion adsorption. Benefited from that, the composite aerogels exhibit significantly enhanced supercapacitor properties in both aq. and ionic liq. electrolyte. Compared with graphene aerogels, the composite aerogels show a 37% larger specific capacitance of 245.5 F g-1 at a c.d. of 2.5 A g-1 and high rate capability of 197.0 F g-1 at a high c.d. of 80 A g-1 in aq. electrolyte. Moreover, the composite aerogels deliver a 33% larger specific capacitance of 183.3 F g-1 at 0.5 A g-1 and a high energy d. of 80 Wh kg-1 when using an ionic liq. (EMIMBF4) as the electrolyte.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFOmsrfK&md5=a7ea347381a67369ad5a759d104ad822
170. 170
  Georgakilas, V.; Demeslis, A.; Ntararas, E.; Kouloumpis, A.; Dimos, K.; Gournis, D.; Kocman, M.; Otyepka, M.; Zboril, R. Hydrophilic Nanotube Supported Graphene-Water Dispersible Carbon Superstructure with Excellent Conductivity Adv. Funct. Mater. 2015, 25, 1481– 1487 DOI: 10.1002/adfm.201403801
  
  170
  Hydrophilic Nanotube Supported Graphene-Water Dispersible Carbon Superstructure with Excellent Conductivity
  
  Georgakilas, Vasilios; Demeslis, Athanasios; Ntararas, Evangelos; Kouloumpis, Antonios; Dimos, Konstantinos; Gournis, Dimitrios; Kocman, Mikulas; Otyepka, Michal; Zboril, Radek
  
  Advanced Functional Materials (2015), 25 (10), 1481-1487CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  In this work, it is shown that the hydrophilic functionalized multiwall carbon nanotubes (MWCNs) can stabilize a large amt. of pristine graphene nanosheets in pure water without the assistance of surfactants, ionic liqs., or hydrophilic polymers. Role of stabilizer is conveyed by highly hydrophilic carbon nanotubes, functionalized by dihydroxy Ph groups, affording a stable dispersion at concns. as high as 15 mg mL-1. Such multidimensional (2D/1D) graphene/MWCN hybrid is found to be dispersible also in other polar org. solvents such as ethanol, isopropanol, N,N-dimethylformamide, ethylene glycol, and their mixts. High-resoln. transmission microscopy and at. force microscopy (AFM) including a liq. mode AFM manifest several types of interaction including trapping of multiwalled carbon nanotubes between the graphene sheets or the modification of graphene edges. Mol. dynamic simulations show that formation of an assembly is kinetically controlled. Importantly, the hybrid can be deposited on the paper by drop casting or dispersed in water-sol. polymers resulting in record values of elec. cond. (sheet resistance up to Rs ≈ 25 Ω sq-1 for free hybrid material and Rs ≈ 1300 Ω sq-1 for a polyvinilalc./hybrid composite film). Thus, these novel water dispersible carbon superstructures reveal a high application potential as conductive inks for inkjet printing or as highly conductive polymers.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXosFKktQ%253D%253D&md5=36000c5625e0be1a46c580feaf61e2ed
171. 171
  Tang, C.; Long, G.; Hu, X.; Wong, K.; Lau, W. M.; Fan, M.; Mei, J.; Xu, T.; Wang, B.; Huid, D. Conductive Polymer Nanocomposites with Hierarchical Multi-Scale Structures via Self-Assembly of Carbon-Nanotubes on Graphene on Polymer-microspheres Nanoscale 2014, 6, 7877– 7888 DOI: 10.1039/c3nr06056j
  
  171
  Conductive polymer nanocomposites with hierarchical multi-scale structures via self-assembly of carbon-nanotubes on graphene on polymer-microspheres
  
  Tang, Changyu; Long, Gucheng; Hu, Xin; Wong, Ka-wai; Lau, Woon-ming; Fan, Meikun; Mei, Jun; Xu, Tao; Wang, Bin; Hui, David
  
  Nanoscale (2014), 6 (14), 7877-7888CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  A novel and highly conductive 3-dimensional (3D) hierarchical multi-scale structure is formed by a new, simple, facile, and water-based method that enables practical prodn. of conductive carbon nanofiller/polymer composites. More specifically, the π-π interaction between CNTs and graphene oxide (GO) is exploited to disperse conductive but non-polar CNTs with amphiphilic GO sheets to form a stable aq. colloidal soln. Aq.-dispersible latex-polystyrene microspheres are then added to enable the self-assembly processes of anchoring CNTs on GO and wrapping microspheres with GO-stabilized CNTs for the formation of an intriguing 3D hierarchical multi-scale structure. During this process, GO is reduced to conductive reduced-graphene oxide (RGO). The resultant RGO sheets act as 'nano-walls' to prevent CNTs from randomly diffusing into the polymer bulk during thermal pressing of RGO-CNT/microspheres, which results in the formation of a 3D foam-like network of RGO-CNTs with high quality. The resultant composite with such a structure gives an ultra-low percolation threshold (0.03 vol% RGO-CNTs) and a reasonably high cond. (153 S m-1 at 4 vol% RGO-CNTs), which could satisfy various applications requiring both transparency and elec. conduction characteristics (e.g. transparent antistatic coatings, capacitive touch-screens, and transparent electronic devices).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVKjtr%252FO&md5=9acb5c6399f254e22d3ffd591dfbca6c
172. 172
  Li, G.; Shrotriya, V.; Huang, J. S.; Yao, Y.; Moriarty, T.; Emery, K.; Yang, Y. High-Efficiency Solution Processable Polymer Photovoltaic Cells by Self-Organization of Polymer Blends Nat. Mater. 2005, 4, 864– 868 DOI: 10.1038/nmat1500
  
  172
  High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends
  
  Li, Gang; Shrotriya, Vishal; Huang, Jinsong; Yao, Yan; Moriarty, Tom; Emery, Keith; Yang, Yang
  
  Nature Materials (2005), 4 (11), 864-868CODEN: NMAACR; ISSN:1476-1122. (Nature Publishing Group)
  
  Converting solar energy into electricity provides a much-needed soln. to the energy crisis the world is facing today. Polymer solar cells showed potential to harness solar energy in a cost-effective way. Significant efforts are underway to improve their efficiency to the level of practical applications. Here, the authors report highly efficient polymer solar cells based on a bulk heterojunction of polymer poly(3-hexylthiophene) and methanofullerene. Controlling the active layer growth rate results in an increased hole mobility and balanced charge transport. Together with increased absorption in the active layer, this results in much-improved device performance, particularly in external quantum efficiency. The power-conversion efficiency of 4.4% achieved here is the highest published so far for polymer-based solar cells. The soln. process involved ensures that the fabrication cost remains low and the processing is simple. The high efficiency achieved in this work brings these devices one step closer to commercialization.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXht1ShsbnO&md5=8bf7c1bf188a6b0b96a895552a90fe22
173. 173
  Kim, J. Y.; Lee, K.; Coates, N. E.; Moses, D.; Nguyen, T. Q.; Dante, M.; Heeger, A. J. Efficient Tandem Polymer Solar Cells Fabricated by All-Solution Processing Science 2007, 317, 222– 225 DOI: 10.1126/science.1141711
  
  173
  Efficient Tandem Polymer Solar Cells Fabricated by All-Solution Processing
  
  Kim, Jin Young; Lee, Kwanghee; Coates, Nelson E.; Moses, Daniel; Nguyen, Thuc-Quyen; Dante, Mark; Heeger, Alan J.
  
  Science (Washington, DC, United States) (2007), 317 (5835), 222-225CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  Tandem solar cells, in which two solar cells with different absorption characteristics are linked to use a wider range of the solar spectrum, were fabricated with each layer processed from soln. using bulk heterojunction materials comprising semiconducting polymers and fullerene derivs. A transparent titanium oxide (TiOx) layer separates and connects the front cell and the back cell. The TiOx layer serves as an electron transport and collecting layer for the 1st cell and as a stable foundation that enables the fabrication of the 2nd cell to complete the tandem cell architecture. The authors use an inverted structure with the low band-gap polymer-fullerene composite as the charge-sepg. layer in the front cell and the high band-gap polymer composite as that in the back cell. Power-conversion efficiencies of >6% were achieved at illuminations of 200 mW per square centimeter.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXnsFaqtr4%253D&md5=ca755156c911cdd36928e67976822375
174. 174
  Guenes, S.; Neugebauer, H.; Sariciftci, N. S. Conjugated Polymer-Based Organic Solar Cells Chem. Rev. 2007, 107, 1324– 1338 DOI: 10.1021/cr050149z
  
  There is no corresponding record for this reference.
175. 175
  Kim, Y.; Cook, S.; Tuladhar, S. M.; Choulis, S. A.; Nelson, J.; Durrant, R. J.; Bradley, D. D. C.; Giles, M.; Mcculloch, I.; Ha, C. S. A Strong Regioregularity Effect in Self-Organizing Conjugated Polymer Films and High-Efficiency Polythiophene: Fullerene Solar Cells Nat. Mater. 2006, 5, 197– 203 DOI: 10.1038/nmat1574
  
  175
  A strong regioregularity effect in self-organizing conjugated polymer films and high-efficiency polythiophene:fullerene solar cells
  
  Kim, Youngkyoo; Cook, Steffan; Tuladhar, Sachetan M.; Choulis, Stelios A.; Nelson, Jenny; Durrant, James R.; Bradley, Donal D. C.; Giles, Mark; McCulloch, Iain; Ha, Chang-Sik; Ree, Moonhor
  
  Nature Materials (2006), 5 (3), 197-203CODEN: NMAACR; ISSN:1476-1122. (Nature Publishing Group)
  
  Low-cost photovoltaic energy conversion using conjugated mol. materials has become increasingly feasible through the development of org. Bulk heterojunction (BHJ) structures, where efficient light-induced charge sepn. is enabled by a large-area donor-acceptor interface. The highest efficiencies were achieved using blends of poly(3-hexylthiophene) (P3HT) and a fullerene deriv., but performance depends critically on the material properties and processing conditions. This variability is believed to be influenced by the self-organizing properties of P3HT, which means that both optical and electronic properties are sensitive to the mol. packing. However, the relation between mol. nanostructure, optoelectronic properties of the blend material and device performance has not yet been demonstrated. Here the authors focus on the influence of polymer regioregularity (RR) on the mol. nanostructure, and hence on the resulting material properties and device performance. The authors find a strong influence of RR on solar-cell performance, which can be attributed to enhanced optical absorption and transport resulting from the organization of P3HT chains and domains. Further optimization of devices using the highest RR material resulted in a power conversion efficiency of 4.4%, even without optimization of electrodes.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XhvV2ju7k%253D&md5=403a8eec83802fddd8ebd93a935b61b9
176. 176
  Qu, S.; Li, M.; Xie, L.; Huang, X.; Yang, J.; Wang, N.; Yang, S. Noncovalent Functionalization of Graphene Attaching [6,6]-Phenyl-C₆₁-butyric Acid Methyl Ester (PCBM) and Application as Electron Extraction Layer of Polymer Solar Cells ACS Nano 2013, 7, 4070– 4081 DOI: 10.1021/nn4001963
  
  176
  Noncovalent functionalization of graphene attaching [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and application as electron extraction layer of polymer solar cells
  
  Qu, Shuxuan; Li, Minghua; Xie, Lixin; Huang, Xiao; Yang, Jinguo; Wang, Nan; Yang, Shangfeng
  
  ACS Nano (2013), 7 (5), 4070-4081CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  A new graphene-fullerene composite (rGO-pyrene-PCBM), in which [6,6]-phenyl-C61-butyric acid Me ester (PCBM) was attached onto reduced graphene oxide (rGO) via the noncovalent functionalization approach, was reported. The pyrene-PCBM moiety was synthesized via a facile esterification reaction, and pyrene was used as an anchoring bridge to link rGO and PCBM components. FTIR, UV-vis, and XPS spectroscopic characterizations were carried out to confirm the hybrid structure of rGO-pyrene-PCBM, and the composite formation is found to improve greatly the dispersity of rGO in DMF. The geometric configuration of rGO-pyrene-PCBM was studied by Raman, SEM, and AFM analyses, suggesting that the C60 moiety is far from the graphene sheet and is bridged with the graphene sheet via the pyrene anchor. Finally rGO-pyrene-PCBM was successfully applied as electron extn. layer for P3HT:PCBM bulk heterojunction polymer solar cell (BHJ-PSC) devices, affording a PCE of 3.89%, which is enhanced by ca. 15% compared to that of the ref. device without electron extn. layer (3.39%). Contrarily, the comparative devices incorporating the rGO or pyrene-PCBM component as electron extn. layer showed dramatically decreased PCE, indicating the importance of composite formation between rGO and pyrene-PCBM components for its electron extn. property.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXmtVymtLw%253D&md5=1fda5dc3f9a13228b984a46a000f4d01
177. 177
  Gan, T.; Hu, C.; Sun, Z.; Hu, S. Facile Synthesis of Water-Soluble Fullerene–Graphene Oxide Composites for Electrodeposition of Phosphotungstic Acid-Based Electrocatalysts Electrochim. Acta 2013, 111, 738– 745 DOI: 10.1016/j.electacta.2013.08.059
  
  177
  Facile synthesis of water-soluble fullerene-graphene oxide composites for electrodeposition of phosphotungstic acid-based electrocatalysts
  
  Gan, Tian; Hu, Chengguo; Sun, Zhe; Hu, Shengshui
  
  Electrochimica Acta (2013), 111 (), 738-745CODEN: ELCAAV; ISSN:0013-4686. (Elsevier Ltd.)
  
  A versatile approach to the dispersion of C60/C70 in water with high concn. and stability by graphene oxide (GO) was reported here. By simply grinding with GO, C60/C70 can be readily dissolved in water with soly. up to 5 mg mL-1 and stability for more than three months. TEM indicated that C60/C70 formed a uniform and high-d. layer on the surface of GO, which may be achieved through the strong π-π interaction between fullerenes and GO, as supported by Fourier transform IR spectroscopy, Raman and UV-visible spectroscopy spectra. Through a simple electrodeposition method, two novel phosphotungstic acid-graphene oxide-fullerene hybrids (i.e., PTA-GO-C60 and PTA-GO-C70) were formed on glassy carbon electrodes. The resulting hybrid modified electrodes exhibited enhanced electrocatalytic activity for the oxidn. of a variety of small biomols., including dopamine, ascorbic acid, uric acid, L-tryptophan, tyrosine, indole-3-acetic acid, salicylic acid and 6-benzylaminopurine, reflected by the remarkably enlarged peak currents and apparently reduced oxidn. overpotentials as compared with those on either PTA or PTA-GO modified electrodes.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslCqs7vL&md5=9b6854ebe9e6c620fad9be9e25b5000f
178. 178
  Ba, H.; Podila, S.; Liu, Y.; Mua, X.; Nhuta, J. M.; Papaefthimiou, V.; Zafeiratos, S.; Granger, P.; Huu, C. P. Nanodiamond Decorated Few-Layer Graphene Composite as Anefficient Metal-Free Dehydrogenation Catalyst for Styrene Production Catal. Today 2015, 249, 167– 175 DOI: 10.1016/j.cattod.2014.10.029
  
  178
  Nanodiamond decorated few-layer graphene composite as an efficient metal-free dehydrogenation catalyst for styrene production
  
  Ba, Housseinou; Podila, Seetharamulu; Liu, Yuefeng; Mu, Xiaoke; Nhut, Jean-Mario; Papaefthimiou, Vasiliki; Zafeiratos, Spyridon; Granger, Pascal; Pham-Huu, Cuong
  
  Catalysis Today (2015), 249 (), 167-175CODEN: CATTEA; ISSN:0920-5861. (Elsevier B.V.)
  
  Hybrid materials consisting of graphene and nanodiamonds (NDs) can potentially display not only the individual properties of ND and graphene, but also those resulting from synergism when they closely interact. Herein, synergistic effects between ND and few-layer-graphene (FLG) contg. between 5 and 20 layers of graphene are examd. The ND/FLG composite was prepd. by mixing a suspension of FLG in ethanol with NDs. In this case, FLG plays the role of 2D support for dispersing ND clusters while NDs acting as a nano-spacer for partly preventing the re-stacking of the FLG sheets. The as-synthesized hybrid material was further used as metal-free catalyst for the steam-free direct dehydrogenation (DH) of ethylbenzene (EB) to styrene (ST). The DH activity obtained on the ND/FLG catalyst was benchmarked with other catalysts, i.e. com. K-promoted Fe-based catalysts and carbon-based catalysts. The ND/FLG catalyst exhibits the highest DH activity among the tested catalysts, esp. with a dehydrogenation specific rate as high as 19 mmolST g-1ND h-1 along with a selectivity toward styrene up to 95% at reaction temp. at 600°C. The catalyst displays a relatively high stability as a function of time on stream while the deactivated catalyst can be easily regenerated by an oxidative treatment in mild temp. conditions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFWisrrM&md5=a5919f272e2bad21f67497aa0d8aab1a
179. 179
  Pastor, I. R.; Fernandez, G. R.; Rizo, H. V.; Terrones, M.; Gullon, I. M. Towards the Understanding of the Graphene Oxide Structure: How to Control the Formation of Humic- and Fulvic-Like Oxidized Debris Carbon 2015, 84, 299– 309 DOI: 10.1016/j.carbon.2014.12.027
  
  There is no corresponding record for this reference.
180. 180
  Rourke, J. P.; Pandey, P. A.; Moore, J. J.; Bates, M.; Kinloch, I. A.; Young, R. J.; Wilson, N. R. The Real Graphene Oxide Revealed: Stripping the Oxidative Debris from the Graphene Like Sheets Angew. Chem., Int. Ed. 2011, 50, 3173– 3177 DOI: 10.1002/anie.201007520
  
  There is no corresponding record for this reference.
181. 181
  Thomas, H. R.; Valles, C.; Young, R. J.; Kinloch, I. A.; Wilson, N. R.; Rourke, J. P. Identifying the Fluorescence of Graphene Oxide J. Mater. Chem. C 2013, 1, 338– 342 DOI: 10.1039/C2TC00234E
  
  181
  Identifying the fluorescence of graphene oxide
  
  Thomas, Helen R.; Valles, Cristina; Young, Robert J.; Kinloch, Ian A.; Wilson, Neil R.; Rourke, Jonathan P.
  
  Journal of Materials Chemistry C: Materials for Optical and Electronic Devices (2013), 1 (2), 338-342CODEN: JMCCCX; ISSN:2050-7534. (Royal Society of Chemistry)
  
  Treatment of graphene oxide (GO) with NaOH separates the material into 2 components: a colorless, but highly fluorescent, oxidative debris and a darker nonfluorescent material contg. the graphene-like sheets. The as-produced GO shows a weak, broad luminescence while the oxidative debris fluoresces more intensely, blue-shifted relative to the as-produced GO, with a dispersive emission profile shifting to lower wavelength as the excitation wavelength is decreased. Such excitation wavelength dependent luminescence is characteristic of ensembles of nm-sized C-based fluorophores. Anal. of the fluorescence as a function of excitation wavelength for as-produced graphene oxide shows a single nondispersive peak, consistent with broadening of the emission from a single species rather than an ensemble of quantum dots within the graphene sheet.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhvVWgsrrE&md5=be9946164f459b455b22cfea3d46fbd0
182. 182
  Bonanni, A.; Ambrosi, A.; Chua, C. K.; Pumera, M. Oxidation Debris in Graphene Oxide Is Responsible for Its Inherent Electroactivity ACS Nano 2014, 8, 4197– 4204 DOI: 10.1021/nn404255q
  
  182
  Oxidation Debris in Graphene Oxide Is Responsible for Its Inherent Electroactivity
  
  Bonanni, Alessandra; Ambrosi, Adriano; Chua, Chun Kiang; Pumera, Martin
  
  ACS Nano (2014), 8 (5), 4197-4204CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Graphene oxide is known to exhibit many interesting properties, ranging from inherent fluorescence to inherent electrochem., just to name a few. Recent research found that graphene oxide is a composite material consisting of the so-called oxidn. debris and unoxidized graphene fragments. Surprisingly, the oxidn. debris, which contains small and highly oxidized arom. fragments adsorbed on graphene surfaces, is responsible for the excellent soly. and inherent fluorescence of graphene oxide. Here, the authors examine the origin of the inherent electroactivity of graphene oxide and demonstrate that such phenomenon is attributed to the presence of oxidn. debris. The authors sep. oxidn. debris from the less oxidized graphene backbone in as-prepd. graphene oxide nanoplatelets using ultrasonication. The extension of ultrasonication time corresponded to a larger amt. of oxidn. debris released from the graphene oxide nanoplatelets' surfaces and subsequently caused detrimental effects to the inherent electroactivity of the graphene material. Since graphene oxide is often the material of choice for energy storage devices, such as batteries and supercapacitors, a thorough understanding on the origin of such inherent electrochem. properties of graphene oxide is of very high importance.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXntFOmtbw%253D&md5=b8a85a4c2411adc4ae6065b29bde8f54
183. 183
  Coluci, V. R.; Martinez, D. S. T.; Honório, J. G.; de Faria, A. F.; Morales, D. A.; Skaf, M. S.; Alves, O. L.; Umbuzeiro, G. A. Noncovalent Interaction with Graphene Oxide: The Crucial Role of Oxidative Debris J. Phys. Chem. C 2014, 118, 2187– 2193 DOI: 10.1021/jp409501g
  
  183
  Noncovalent Interaction with Graphene Oxide: The Crucial Role of Oxidative Debris
  
  Coluci, Vitor R.; Martinez, Diego Stefani T.; Honorio, Jaqueline G.; de Faria, Andreia F.; Morales, Daniel A.; Skaf, Munir S.; Alves, Oswaldo L.; Umbuzeiro, Gisela A.
  
  Journal of Physical Chemistry C (2014), 118 (4), 2187-2193CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
  
  Graphene oxide (GO) is a very promising material because it is easy to process, water-sol., and chem. versatile due to the presence of oxygenated groups on its surface. GO has been used in different areas such as electronics, biosensing, and environmental remediation. To design efficient materials, esp. for biosensing and for remediating pollutants, the knowledge of surface noncovalent interaction and functionalization is crucial. Recently, it has been suggested revisions on the structural models of GO because the presence of highly oxidized polyarom. carboxylated fragments (oxidative debris) on the GO surfaces. These debris are produced during acid treatments commonly employed in GO synthesis and purifn. Here we applied chem. anal., bioassays, and atomistic simulations to study the influence of oxidative debris on the noncovalent interaction of GO sheets with an important org. pollutant (e.g., 1-nitropyrene). GO samples without oxidative debris were found to be 75% more effective to adsorb 1-nitropyrene than samples with debris. Our results suggest that small (∼1 nm) oxidative debris are responsible for preventing adsorption sites on GO surfaces from being reached by potentially adsorbate mols.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXlslCrtQ%253D%253D&md5=9f5c64a2ec930459611aec874a64ed18
184. 184
  Gupta, A.; Sakthivel, T.; Seal, S. Recent Development in 2D Materials beyond Graphene Prog. Mater. Sci. 2015, 73, 44– 126 DOI: 10.1016/j.pmatsci.2015.02.002
  
  184
  Recent development in 2D materials beyond graphene
  
  Gupta, Ankur; Sakthivel, Tamilselvan; Seal, Sudipta
  
  Progress in Materials Science (2015), 73 (), 44-126CODEN: PRMSAQ; ISSN:0079-6425. (Elsevier Ltd.)
  
  Discovery of graphene and its astonishing properties have given birth to a new class of materials known as "2D materials". Motivated by the success of graphene, alternative layered and non-layered 2D materials have become the focus of intense research due to their unique phys. and chem. properties. Origin of these properties ascribed to the dimensionality effect and modulation in their band structure. This review highlights the recent progress of the state-of-the-art research on synthesis, characterization and isolation of single and few layer nanosheets and their assembly. Electronic, magnetic, optical and mech. properties of 2D materials have also been reviewed for their emerging applications in the area of catalysis, electronic, optoelectronic and spintronic devices; sensors, high performance electrodes and nanocomposites. Finally this review concludes with a future prospective to guide this fast evolving class of 2D materials in next generation materials science.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlt1equ7k%253D&md5=c9b5cf4e5e46142d86afc19276ea8048
185. 185
  Wang, Q. H.; Kalantar-Zadeh, K.; Kis, A.; Coleman, J. N.; Strano, M. S. Electronics and Optoelectronics of Two Dimensional Transition Metal Dichalcogenides Nat. Nanotechnol. 2012, 7, 699– 712 DOI: 10.1038/nnano.2012.193
  
  185
  Electronics and optoelectronics of two-dimensional transition metal dichalcogenides
  
  Wang, Qing Hua; Kalantar-Zadeh, Kourosh; Kis, Andras; Coleman, Jonathan N.; Strano, Michael S.
  
  Nature Nanotechnology (2012), 7 (11), 699-712CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
  
  A review. The remarkable properties of graphene have renewed interest in inorg., two-dimensional materials with unique electronic and optical attributes. Transition metal dichalcogenides (TMDCs) are layered materials with strong in-plane bonding and weak out-of-plane interactions enabling exfoliation into two-dimensional layers of single unit cell thickness. Although TMDCs were studied for decades, recent advances in nanoscale materials characterization and device fabrication have opened up new opportunities for two-dimensional layers of thin TMDCs in nanoelectronics and optoelectronics. TMDCs such as MoS2, MoSe2, WS2 and WSe2 have sizable bandgaps that change from indirect to direct in single layers, allowing applications such as transistors, photodetectors and electroluminescent devices. The authors review the historical development of TMDCs, methods for prepg. atomically thin layers, their electronic and optical properties, and prospects for future advances in electronics and optoelectronics.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1ajtr7P&md5=4e45d586c6ac7b0676a461f61a53db68
186. 186
  Splendiani, A.; Sun, L.; Zhang, Y.; Li, T.; Kim, J.; Chim, C. Y.; Galli, G.; Wang, F. Emerging Photoluminescence in Monolayer MoS₂ Nano Lett. 2010, 10, 1271– 1275 DOI: 10.1021/nl903868w
  
  186
  Emerging Photoluminescence in Monolayer MoS2
  
  Splendiani, Andrea; Sun, Liang; Zhang, Yuanbo; Li, Tianshu; Kim, Jonghwan; Chim, Chi-Yung; Galli, Giulia; Wang, Feng
  
  Nano Letters (2010), 10 (4), 1271-1275CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Novel phys. phenomena can emerge in low-dimensional nanomaterials. Bulk MoS2, a prototypical metal dichalcogenide, is an indirect bandgap semiconductor with negligible photoluminescence. When the MoS2 crystal is thinned to monolayer, however, a strong photoluminescence emerges, indicating an indirect to direct bandgap transition in this d-electron system. Quantum confinement in layered d-electron materials like MoS2 provides new opportunities for engineering the electronic structure of matter at the nanoscale.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXjt1Sqsbs%253D&md5=7df269b35ce26d97dd8fbec1d8b6117d
187. 187
  Thripuranthaka, M.; Late, D. J. Temperature Dependent Phonon Shifts in Single-Layer WS₂ ACS Appl. Mater. Interfaces 2014, 6, 1158– 1163 DOI: 10.1021/am404847d
  
  There is no corresponding record for this reference.
188. 188
  Miremadi, B. K.; Morrison, S. R. High Activity Catalyst from Exfoliated MoS₂ J. Catal. 1987, 103, 334– 345 DOI: 10.1016/0021-9517(87)90125-4
  
  188
  High activity catalyst from exfoliated molybdenum disulfide
  
  Miremadi, Bijan K.; Morrison, S. Roy
  
  Journal of Catalysis (1987), 103 (2), 334-45CODEN: JCTLA5; ISSN:0021-9517.
  
  Unusually high activity catalysts were prepd. by using exfoliated MoS2 suspended as single layers in soln. The hydrogenation of CO was used as the model reaction. The process depends on 3 features in the prepn.: the prepn. of the single mol. layer MoS2, the deposition of these as single layers onto high-surface-area Al2O3 or deposition of Al2O3 onto single layers of MoS2 and the deposition of monolayers of Ni onto the single layers of MoS2. With this structure, suitably calcined and reduced to improve the interaction between Mo, Ni, and Al2O3, a very high d. of active sites per unit area was obtained. The most active sites are a form of oxysulfide. The active sites behave differently from Ni supported on Al2O3. The Ni/Mo/Al2O3 compn. yields CO2 as the byproduct of methanation, instead of the H2O obsd. with the Ni/Al2O3 compn., and has a different activation energy. A specific formulation designed to give the max. d. of accessible Ni/Mo/Al2O3 sites shows an activity substantially higher than Ni/Al2O3. The activity of catalysts prepd. by exfoliation is substantially higher than that of those prepd. by pptn. from ammonium heptamolybdate.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL2sXhsVCksrk%253D&md5=b22856197973beda281bfdf798695533
189. 189
  Novoselov, K. S.; Jiang, D.; Schedin, F.; Booth, T. J.; Khotkevich, V. V.; Morozov, S. V.; Geim, A. K. Two-Dimensional Atomic Crystals Proc. Natl. Acad. Sci. U. S. A. 2005, 102, 10451– 10453 DOI: 10.1073/pnas.0502848102
  
  189
  Two-dimensional atomic crystals
  
  Novoselov, K. S.; Jiang, D.; Schedin, F.; Booth, T. J.; Khotkevich, V. V.; Morozov, S. V.; Geim, A. K.
  
  Proceedings of the National Academy of Sciences of the United States of America (2005), 102 (30), 10451-10453CODEN: PNASA6; ISSN:0027-8424. (National Academy of Sciences)
  
  The authors report free-standing at. crystals that are strictly 2-dimensional and can be viewed as individual at. planes pulled out of bulk crystals or as unrolled single-wall nanotubes. By using micromech. cleavage, the authors prepd. and studied a variety of 2-dimensional crystals including single layers of boron nitride, graphite, several dichalcogenides, and complex oxides. These atomically thin sheets (essentially gigantic 2-dimensional mols. unprotected from the immediate environment) are stable under ambient conditions, exhibit high crystal quality, and are continuous on a macroscopic scale.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXntVSit7g%253D&md5=1ce9e5f5eb0f7b9abb033d4a690d49c3
190. 190
  Coleman, J. N.; Lotya, M.; O’Neill, A.; Bergin, S. D.; King, P. J.; Khan, U.; Young, K.; Gaucher, A.; De, S.; Smith, R. J. Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials Science 2011, 331, 568– 571 DOI: 10.1126/science.1194975
  
  190
  Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials
  
  Coleman, Jonathan N.; Lotya, Mustafa; O'Neill, Arlene; Bergin, Shane D.; King, Paul J.; Khan, Umar; Young, Karen; Gaucher, Alexandre; De, Sukanta; Smith, Ronan J.; Shvets, Igor V.; Arora, Sunil K.; Stanton, George; Kim, Hye-Young; Lee, Kangho; Kim, Gyu Tae; Duesberg, Georg S.; Hallam, Toby; Boland, John J.; Wang, Jing Jing; Donegan, John F.; Grunlan, Jaime C.; Moriarty, Gregory; Shmeliov, Aleksey; Nicholls, Rebecca J.; Perkins, James M.; Grieveson, Eleanor M.; Theuwissen, Koenraad; McComb, David W.; Nellist, Peter D.; Nicolosi, Valeria
  
  Science (Washington, DC, United States) (2011), 331 (6017), 568-571CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  If they could be easily exfoliated, layered materials would become a diverse source of two-dimensional crystals whose properties would be useful in applications ranging from electronics to energy storage. Layered compds. such as MoS2, WS2, MoSe2, MoTe2, TaSe2, NbSe2, NiTe2, BN, and Bi2Te3 can be efficiently dispersed in common solvents and can be deposited as individual flakes or formed into films. Electron microscopy strongly suggests that the material is exfoliated into individual layers. By blending this material with suspensions of other nanomaterials or polymer solns., the authors can prep. hybrid dispersions or composites, which can be cast into films. WS2 and MoS2 effectively reinforce polymers, whereas WS2/carbon nanotube hybrid films have high cond., leading to promising thermoelec. properties.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtlWisLY%253D&md5=7bd4a9da1b4f81f2caa3d1159dd8a5c7
191. 191
  Song, S. H.; Kim, B. H.; Choe, D. H.; Kim, J.; Kim, D. C.; Lee, D. J.; Kim, J. M.; Chang, K. J.; Jeon, S. Bandgap Widening of Phase Quilted, 2D MoS2 by Oxidative Intercalation Adv. Mater. 2015, 27, 3152– 3158 DOI: 10.1002/adma.201500649
  
  191
  Bandgap Widening of Phase Quilted, 2D MoS2 by Oxidative Intercalation
  
  Song, Sung Ho; Kim, Bo Hyun; Choe, Duk-Hyun; Kim, Jin; Kim, Dae Chul; Lee, Dong Ju; Kim, Jung Mo; Chang, Kee Joo; Jeon, Seokwoo
  
  Advanced Materials (Weinheim, Germany) (2015), 27 (20), 3152-3158CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  The authors have demonstrated an advance in the bandgap tuning of 2D MoS2 through the control of oxidn. during exfoliation. In the process of making an intercalation compd. of 2D transition metal dichalcogenides (TMDs), it was possible to perform in situ exfoliation and oxidn. of 2D materials with large and thin flake sizes up to 10 000 μm2. The bandgaps of oxidized h-MoSxOy extended into the visible range, suggesting that fine control of oxidn. can be exploited for the bandgap engineering of the 2D TMDs. The underlying mechanism for the bandgap widening of 2D TMDs in this study is the structural phase transition which induces a complex structure composed of quilted phases of h-MoSxOy. The selective oxidn. technique can modulate the bandgap of 2D TMDs in the visible range, providing a new route to bandgap engineering.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmtlKmt78%253D&md5=d40d170af35806e44c5fab5857f0ac3a
192. 192
  Zhan, Y.; Liu, Z.; Najmaei, S.; Ajayan, P. M.; Lou, J. Large-Area Vapor-Phase Growth and Characterization of MoS₂ Atomic Layers on a SiO₂ Substrate Small 2012, 8, 966– 971 DOI: 10.1002/smll.201102654
  
  192
  Large-Area Vapor-Phase Growth and Characterization of MoS2 Atomic Layers on a SiO2 Substrate
  
  Zhan, Yongjie; Liu, Zheng; Najmaei, Sina; Ajayan, Pulickel M.; Lou, Jun
  
  Small (2012), 8 (7), 966-971CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Monolayer Mo disulfide (MoS2), a two-dimensional crystal with a direct bandgap, is a promising candidate for 2-dimensional nanoelectronic devices complementing graphene. There were recent attempts to produce MoS2 layers via chem. and mech. exfoliation of bulk material. Here the authors demonstrate the large area growth of MoS2 at. layers on SiO2 substrates by a scalable CVD method. The as-prepd. samples can either be readily used for further device fabrication or be easily released from SiO2 and transferred to arbitrary substrates. High resoln. TEM and Raman spectroscopy on the as grown films of MoS2 indicate that the no. of layers range from single layer to a few layers. The authors' results on the direct growth of MoS2 layers on dielec. leading to facile device fabrication possibilities show the expanding set of useful 2-dimensional at. layers, on the heels of graphene, which can be controllably synthesized and manipulated for many applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xitlyht70%253D&md5=a39ddda9639d32ad598a487b777d1968
193. 193
  Lee, Y. H.; Zhang, X. Q.; Zhang, W. J.; Chang, M. T.; Lin, C. T.; Chang, K. D.; Yu, Y. C.; Wang, J. T. W.; Chang, C. S.; Li, L. J. Synthesis of Large-Area MoS₂ Atomic Layers with Chemical Vapor Deposition Adv. Mater. 2012, 24, 2320– 2325 DOI: 10.1002/adma.201104798
  
  193
  Synthesis of Large-Area MoS2 Atomic Layers with Chemical Vapor Deposition
  
  Lee, Yi-Hsien; Zhang, Xin-Quan; Zhang, Wenjing; Chang, Mu-Tung; Lin, Cheng-Te; Chang, Kai-Di; Yu, Ya-Chu; Wang, Jacob Tse-Wei; Chang, Chia-Seng; Li, Lain-Jong; Lin, Tsung-Wu
  
  Advanced Materials (Weinheim, Germany) (2012), 24 (17), 2320-2325CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Large-area MoS2 at. layers are synthesized on SiO2 substrates by chem. vapor deposition using MoO3 and S powders as the reactants. Optical, microscopic and elec. measurements suggest that the synthetic process leads to the growth of MoS2 monolayer. The TEM images verify that the synthesized MoS2 sheets are highly cryst. To check for elec. performance bottom-gated transistors on silica/silicon using photolithog. was fabricated directly on top of the MoS2 sheets. The transfer curve (drain current vs. gate voltage) was computed and field effect mobility was detd. from anal. of the curve.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XkvVKiur8%253D&md5=7b5ca7016ced6baa546a93be5bbe8589
194. 194
  Zhang, Y.; Chang, T. R.; Zhou, B.; Cui, Y. T.; Yan, H.; Liu, Z.; Schmitt, F.; Lee, J.; Moore, R.; Chen, Y. Direct Observation of the Transition from Indirect to Direct Bandgap in Atomically Thin Epitaxial MoSe₂ Nat. Nanotechnol. 2013, 9, 111– 115 DOI: 10.1038/nnano.2013.277
  
  There is no corresponding record for this reference.
195. 195
  Liu, Z.; Song, L.; Zhao, S.; Huang, J.; Ma, L.; Zhang, J.; Lou, J.; Ajayan, P. M. Direct Growth of Graphene/Hexagonal Boron Nitride Stacked Layers Nano Lett. 2011, 11, 2032– 2037 DOI: 10.1021/nl200464j
  
  195
  Direct Growth of Graphene/Hexagonal Boron Nitride Stacked Layers
  
  Liu, Zheng; Song, Li; Zhao, Shizhen; Huang, Jiaqi; Ma, Lulu; Zhang, Jiangnan; Lou, Jun; Ajayan, Pulickel M.
  
  Nano Letters (2011), 11 (5), 2032-2037CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Graphene (G) and at. layers of hexagonal boron nitride (h-BN) are complementary 2-dimensional materials, structurally very similar but with vastly different electronic properties. Recent studies indicate that h-BN at. layers would be excellent dielec. layers to complement graphene electronics. Graphene on h-BN has been realized via peeling of layers from bulk material to create G/h-BN stacks. Considering that both these layers can be independently grown via chem. vapor deposition (CVD) of their precursors on metal substrates, it is feasible that these can be sequentially grown on substrates to create the G/h-BN stacked layers useful for applications. Here we demonstrate the direct CVD growth of h-BN on highly oriented pyrolytic graphite and on mech. exfoliated graphene, as well as the large area growth of G/h-BN stacks, consisting of few layers of graphene and h-BN, via a two-step CVD process. The G/h-BN film is uniform and continuous and could be transferred onto different substrates for further characterization and device fabrication.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXks1Glurs%253D&md5=0e9795dd84ec8b8076c8aa4500884437
196. 196
  Yu, L.; Lee, Y. H.; Ling, X.; Santos, E. J. G.; Shin, Y. C.; Lin, Y.; Dubey, M.; Kaxiras, E.; Kong, J.; Wang, H. Graphene/MoS₂ Hybrid Technology for Large-Scale Two-Dimensional Electronics Nano Lett. 2014, 14, 3055– 3063 DOI: 10.1021/nl404795z
  
  196
  Graphene/MoS2 Hybrid Technology for Large-Scale Two-Dimensional Electronics
  
  Yu, Lili; Lee, Yi-Hsien; Ling, Xi; Santos, Elton J. G.; Shin, Yong Cheol; Lin, Yuxuan; Dubey, Madan; Kaxiras, Efthimios; Kong, Jing; Wang, Han; Palacios, Tomas
  
  Nano Letters (2014), 14 (6), 3055-3063CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Two-dimensional (2D) materials have generated great interest in the past few years as a new toolbox for electronics. This family of materials includes, among others, metallic graphene, semiconducting transition metal dichalcogenides (such as MoS2), and insulating boron nitride. These materials and their heterostructures offer excellent mech. flexibility, optical transparency, and favorable transport properties for realizing electronic, sensing, and optical systems on arbitrary surfaces. In this paper, we demonstrate a novel technol. for constructing large-scale electronic systems based on graphene/molybdenum disulfide (MoS2) heterostructures grown by chem. vapor deposition. We have fabricated high-performance devices and circuits based on this heterostructure, where MoS2 is used as the transistor channel and graphene as contact electrodes and circuit interconnects. We provide a systematic comparison of the graphene/MoS2 heterojunction contact to more traditional MoS2-metal junctions, as well as a theor. investigation, using d. functional theory, of the origin of the Schottky barrier height. The tunability of the graphene work function with electrostatic doping significantly improves the ohmic contact to MoS2. These high-performance large-scale devices and circuits based on this 2D heterostructure pave the way for practical flexible transparent electronics.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXns1CnsLc%253D&md5=0a11e6ee31fb451ac89156554d5831eb
197. 197
  Li, Y.; Wang, H.; Xie, L.; Liang, Y.; Hong, G.; Dai, H. MoS₂ Nanoparticles Grown on Graphene: An Advanced Catalyst for the Hydrogen Evolution Reaction J. Am. Chem. Soc. 2011, 133, 7296– 7299 DOI: 10.1021/ja201269b
  
  197
  MoS2 Nanoparticles Grown on Graphene: An Advanced Catalyst for the Hydrogen Evolution Reaction
  
  Li, Yanguang; Wang, Hailiang; Xie, Liming; Liang, Yongye; Hong, Guosong; Dai, Hongjie
  
  Journal of the American Chemical Society (2011), 133 (19), 7296-7299CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  Advanced materials for electrocatalytic and photoelectrochem. H2O splitting are central to the area of renewable energy. The authors developed a selective solvothermal synthesis of MoS2 nanoparticles on reduced graphene oxide (RGO) sheets suspended in soln. The resulting MoS2/RGO hybrid material possessed nanoscopic few-layer MoS2 structures with an abundance of exposed edges stacked onto graphene, in strong contrast to large aggregated MoS2 particles grown freely in soln. without GO. The MoS2/RGO hybrid exhibited superior electrocatalytic activity in the H evolution reaction (HER) relative to other MoS2 catalysts. A Tafel slope of ∼41 mV/decade was measured for MoS2 catalysts in the HER for the 1st time; this exceeds by far the activity of previous MoS2 catalysts and results from the abundance of catalytic edge sites on the MoS2 nanoparticles and the excellent elec. coupling to the underlying graphene network. The ∼41 mV/decade Tafel slope suggested the Volmer-Heyrovsky mechanism for the MoS2-catalyzed HER, with electrochem. desorption of H as the rate-limiting step.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXltVGgtLo%253D&md5=24655c600b394dc7cea91e459dd70ae7
198. 198
  Roy, K.; Padmanabhan, M.; Goswami, S.; Sai, T. P.; Kaushal, S.; Ghosh, A. Optically Active Heterostructures of Graphene and Ultrathin MoS₂ Solid State Commun. 2013, 175, 35– 42 DOI: 10.1016/j.ssc.2013.09.021
  
  There is no corresponding record for this reference.
199. 199
  Roy, K.; Padmanabhan, M.; Goswami, S.; Sai, T. P.; Ramalingam, G.; Raghavan, S.; Ghosh, A. Graphene–MoS₂ Hybrid Structures for Multifunctional Photoresponsive Memory Devices Nat. Nanotechnol. 2013, 8, 826– 830 DOI: 10.1038/nnano.2013.206
  
  199
  Graphene-MoS2 hybrid structures for multifunctional photoresponsive memory devices
  
  Roy, Kallol; Padmanabhan, Medini; Goswami, Srijit; Sai, T. Phanindra; Ramalingam, Gopalakrishnan; Raghavan, Srinivasan; Ghosh, Arindam
  
  Nature Nanotechnology (2013), 8 (11), 826-830CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
  
  Combining the electronic properties of graphene and MoS2 in hybrid heterostructures offers the possibility to create devices with various functionalities. Electronic logic and memory devices have already been constructed from graphene-MoS2 hybrids, but they do not make use of the photosensitivity of MoS2, which arises from its optical-range bandgap. Graphene-on-MoS2 binary heterostructures display remarkable dual optoelectronic functionality, including highly sensitive photodetection and gate-tunable persistent photocond. The responsivity of the hybrids was found to be nearly 1 × 1010 A W-1 at 130 K and 5 × 108 A W-1 at room temp., making them the most sensitive graphene-based photodetectors. When subjected to time-dependent photoillumination, the hybrids could also function as a rewritable optoelectronic switch or memory, where the persistent state shows almost no relaxation or decay within exptl. timescales, indicating near-perfect charge retention. These effects can be quant. explained by gate-tunable charge exchange between the graphene and MoS2 layers, and may lead to new graphene-based optoelectronic devices that are naturally scalable for large-area applications at room temp.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs1Chsr%252FP&md5=f156654fde1c0af91b6ab3e60b477508
200. 200
  Loan, P. T. K.; Zhang, W.; Lin, C. T.; Wei, K. H.; Li, L. J.; Chen, C. H. Graphene/MoS₂ Heterostructures for Ultrasensitive Detection of DNA Hybridisation Adv. Mater. 2014, 26, 4838– 4844 DOI: 10.1002/adma.201401084
  
  200
  Graphene/MoS2 heterostructures for ultrasensitive detection of DNA hybridization
  
  Loan, Phan Thi Kim; Zhang, Wenjing; Lin, Cheng-Te; Wei, Kung-Hwa; Li, Lain-Jong; Chen, Chang-Hsiao
  
  Advanced Materials (Weinheim, Germany) (2014), 26 (28), 4838-4844CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Hwere we reportthat a hetero-structural stacking film graphene on MoS2 provides an excellent and unltrasensitive platform for the detection of DNA hybridization.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXot1Sit7k%253D&md5=ceb0957b706cabc307dad1d9a2bfa62b
201. 201
  Zeng, S.; Hu, S.; Xia, J.; Anderson, T.; Dinh, X. Q.; Meng, X. M.; Coquet, P.; Yong, K. T. Graphene–MoS₂ Hybrid Nanostructures Enhanced Surface Plasmon Resonance Biosensors Sens. Actuators, B 2015, 207, 801– 810 DOI: 10.1016/j.snb.2014.10.124
  
  201
  Graphene-MoS2 hybrid nanostructures enhanced surface plasmon resonance biosensors
  
  Zeng, Shuwen; Hu, Siyi; Xia, Jing; Anderson, Tommy; Dinh, Xuan-Quyen; Meng, Xiang-Min; Coquet, Philippe; Yong, Ken-Tye
  
  Sensors and Actuators, B: Chemical (2015), 207 (Part_A), 801-810CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)
  
  The authors propose a new configuration of surface plasmon resonance (SPR) sensor that is based on graphene-MoS2 hybrid structures for ultrasensitive detection of mols. The proposed system displays a phase-sensitivity enhancement factor of >500-fold when compared to the SPR sensing scheme without the graphene-MoS2 coating or with only graphene coating. The authors' hypothesis is that the monolayer MoS2 has a much higher optical absorption efficiency (∼5%) than that of the graphene layer (∼2.3%). Based on the authors' findings, the electron energy loss of MoS2 layer is comparable to that of graphene and this will allow a successful (∼100%) of light energy transfer to the graphene-MoS2 coated sensing substrate. Such process will lead to a significant enhancement of SPR signals. The authors' simulation shows that a quasi-dark point of the reflected light can be achieved under this condition and this resulted in a steep phase jump at the resonance angle of the authors' newly proposed SPR system. More importantly, phase interrogation detection approach of the graphene-MoS2 hybrid structures-based sensing system is more sensitive than that of using the regularly angular interrogation method and the authors' theor. anal. indicates that 45 nm of Au film thickness and 3 coating layers of MoS2 nanosheet are the optimized parameters needed for the proposed SPR system to achieve the highest detection sensitivity range.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFShtrfP&md5=d2cf09ba6d69b4b5b34f95affb1b604a
202. 202
  Meng, J.; Song, H. D.; Li, C. Z.; Jin, Y.; Tang, L.; Liu, D.; Liao, Z. M.; Xiu, F.; Yu, D. P. Lateral Graphene p-n Junctions Formed by Graphene/MoS₂ Hybrid Interface Nanoscale 2015, 7, 11611– 11619 DOI: 10.1039/C5NR02552D
  
  There is no corresponding record for this reference.
203. 203
  Shiva, K.; Matte, H. S. S. R.; Rajendra, H. B.; Bhattacharyya, A. J.; Rao, C. N. R. Employing Synergistic Interactions Between Few-Layer WS₂ and Reduced Graphene Oxide to Improve Lithium Storage, Cyclability and Rate Capability of Li-Ion Batteries Nano Energy 2013, 2, 787– 793 DOI: 10.1016/j.nanoen.2013.02.001
  
  203
  Employing synergistic interactions between few-layer WS2 and reduced graphene oxide to improve lithium storage, cyclability and rate capability of Li-ion batteries
  
  Shiva, Konda; Ramakrishna Matte, H. S. S.; Rajendra, H. B.; Bhattacharyya, Aninda J.; Rao, C. N. R.
  
  Nano Energy (2013), 2 (5), 787-793CODEN: NEANCA; ISSN:2211-2855. (Elsevier Ltd.)
  
  The aim of the contribution is to introduce a high performance anode alternative to graphite for lithium-ion batteries (LiBs). A simple process was employed to synthesize uniform graphene-like few-layer tungsten sulfide (WS2) supported on reduced graphene oxide (RGO) through a hydrothermal synthesis route. The WS2-RGO (80:20 and 70:30) composites exhibited good enhanced electrochem. performance and excellent rate capability performance when used as anode materials for lithium-ion batteries. The specific capacity of the WS2-RGO composite delivered a capacity of 400-450 mAh g-1 after 50 cycles when cycled at a c.d. of 100 mA g-1. At 4000 mA g-1, the composites showed a stable capacity of approx. 180-240 mAh g-1, resp. The noteworthy electrochem. performance of the composite is not additive, rather it is synergistic in the sense that the electrochem. performance is much superior compared to both WS2 and RGO. As the obsd. lithiation/delithiation for WS2-RGO is at a voltage≈1.0 V (≈0.1 V for graphite, Li+/Li), the lithium-ion battery with WS2-RGO is expected to possess high interface stability, safety and management of elec. energy is expected to be more efficient and economic.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXksFarsrk%253D&md5=e84d464952a2bb7859872f0582b00272
204. 204
  Roy, T.; Tosun, M.; Kang, J. S.; Sachid, A. B.; Desai, S. B.; Hettick, M.; Hu, C. C.; Javey, A. Field-Effect Transistors Built from All Two-Dimensional Material Components ACS Nano 2014, 8, 6259– 6264 DOI: 10.1021/nn501723y
  
  204
  Field-Effect Transistors Built from All Two-Dimensional Material Components
  
  Roy, Tania; Tosun, Mahmut; Kang, Jeong Seuk; Sachid, Angada B.; Desai, Sujay B.; Hettick, Mark; Hu, Chenming C.; Javey, Ali
  
  ACS Nano (2014), 8 (6), 6259-6264CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  We demonstrate field-effect transistors using heterogeneously stacked two-dimensional materials for all of the components, including the semiconductor, insulator, and metal layers. Specifically, MoS2 is used as the active channel material, hexagonal-BN as the top-gate dielec., and graphene as the source/drain and the top-gate contacts. This transistor exhibits n-type behavior with an ON/OFF current ratio of >106, and an electron mobility of ∼33 cm2/V·s. Uniquely, the mobility does not degrade at high gate voltages, presenting an important advantage over conventional Si transistors where enhanced surface roughness scattering severely reduces carrier mobilities at high gate-fields. A WSe2-MoS2 diode with graphene contacts is also demonstrated. The diode exhibits excellent rectification behavior and a low reverse bias current, suggesting high quality interfaces between the stacked layers. In this work, all interfaces are based on van der Waals bonding, presenting a unique device architecture where cryst., layered materials with atomically uniform thicknesses are stacked on demand, without the lattice parameter constraints. The results demonstrate the promise of using an all-layered material system for future electronic applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXntFOgtL8%253D&md5=259674628a1815dcd889fe8df02527b9
205. 205
  Zhang, S.; Zhang, X.; Jiang, G.; Zhu, H.; Guo, S.; Su, D.; Lu, G.; Sun, S. Tuning Nanoparticle Structure and Surface Strain for Catalysis Optimization J. Am. Chem. Soc. 2014, 136, 7734– 7739 DOI: 10.1021/ja5030172
  
  205
  Tuning Nanoparticle Structure and Surface Strain for Catalysis Optimization
  
  Zhang, Sen; Zhang, Xu; Jiang, Guangming; Zhu, Huiyuan; Guo, Shaojun; Su, Dong; Lu, Gang; Sun, Shouheng
  
  Journal of the American Chemical Society (2014), 136 (21), 7734-7739CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  Controlling nanoparticle (NP) surface strain, i.e. compression (or stretch) of surface atoms, is an important approach to tune NP surface chem. and to optimize NP catalysis for chem. reactions. Surface Pt strain in the core/shell FePt/Pt NPs with Pt in 3 at layers can be rationally tuned via core structural transition from cubic solid soln. [denoted as fcc.] structure to tetragonal intermetallic [denoted as face centered tetragonal (fct)] structure. The high activity obsd. from the fct-FePt/Pt NPs for O redn. reaction (ORR) is due to the release of the over-compressed Pt strain by the fct-FePt as suggested by quantum mechanics-mol. mechanics (QM-MM) simulations. The Pt strain effect on ORR can be further optimized when Fe in FePt is partially replaced by Cu. As a result, the fct-FeCuPt/Pt NPs become the most efficient catalyst for ORR and are nearly 10 times more active in specific activity than the com. Pt catalyst. This structure-induced surface strain control opens up a new path to tune and optimize NP catalysis for ORR and many other chem. reactions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXns1Ciu7s%253D&md5=62b0f6656accee9218e9f74971a01fda
206. 206
  Liu, X.; Sui, Y. H.; Meng, C. G.; Han, Y. Tuning the Reactivity of Ru Nanoparticles by Defect Engineering of the Reduced Graphene Oxide Support RSC Adv. 2014, 4, 22230– 22240 DOI: 10.1039/C4RA02900C
  
  206
  Tuning the reactivity of Ru nanoparticles by defect engineering of the reduced graphene oxide support
  
  Liu, Xin; Sui, Yanhui; Meng, Changgong; Han, Yu
  
  RSC Advances (2014), 4 (42), 22230-22240CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  We systematically investigated the electronic structure of Ru nanoparticles supported on various local structures on reduced graphene oxide (rGO) by first-principles-based calcns. We showed that Ru nanoparticles prefer to nucleate at these localized defect structures on rGO, which act as strong trapping sites for Ru nanoparticles and inhibit their aggregation. The binding of Ru nanoparticles to rGO, which is dependent on these local defect structures and correlates with the interfacial charge transfer, dets. the electronic structure of the composites. Further study reveals that the performance of these composites against oxygen adsorption changes proportionally with the shift of the d-band center of the nanoparticles. The correlation between the defect structures on rGO and the reactivity of the composites suggests that controlled modification of the graphenic support by defect engineering would be an efficient way to fabricate new transition metal/rGO composites with high stability and desired reactivity.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXovVegtb4%253D&md5=d80baf8c39f834debb4afb4e404f537d
207. 207
  Duan, J.; Chen, S.; Dai, S.; Qiao, S. Z. Shape Control of Mn₃O₄ Nanoparticles on Nitrogen-Doped Graphene for Enhanced Oxygen Reduction Activity Adv. Funct. Mater. 2014, 24, 2072– 2078 DOI: 10.1002/adfm.201302940
  
  207
  Shape Control of Mn3O4 Nanoparticles on Nitrogen-Doped Graphene for Enhanced Oxygen Reduction Activity
  
  Duan, Jingjing; Chen, Sheng; Dai, Sheng; Qiao, Shi Zhang
  
  Advanced Functional Materials (2014), 24 (14), 2072-2078CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Three kinds of Mn3O4 nanoparticles with different shapes (spheres, cubes, and ellipsoids) are selectively grown on N-doped graphene sheets through a 2-step liq.-phase procedure. These nonprecious hybrid materials display an excellent ORR activity and good durability. The mesoporous microstructure, N doping, and strong bonding between metal species and doped graphene facilitate the ORR catalytic process. Among these 3 kinds of Mn3O4 particles, the ellipsoidal particles on N-doped graphene exhibit the highest ORR activity with a more pos. onset-potential of -0.13 V (close to that of Pt/C, -0.09 V) and a higher kinetic limiting c.d. (JK) of 11.69 mA cm-2 at -0.60 V. The ORR performance of hybrid materials can be correlated to the shape of Mn3O4 nanocrystals, and specifically to the exposed cryst. facets assocd. with a given shape. The shape dependence of Mn3O4 nanoparticles integrated with N-doped graphene on the ORR performance, reported here for the 1st time, may advance the development of fuel cells and metal-air batteries.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvVOhtrvN&md5=a61bcd6ff8df5b81b0dd912d78dee0ab
208. 208
  Li, W.; Wang, F.; Feng, S.; Wang, J.; Sun, Z.; Li, B.; Li, Y.; Yang, J.; Elzatahry, A. A.; Xia, Y. Sol-Gel Design Strategy for Ultradispersed TiO₂ Nanoparticles on Graphene for High-Performance Lithium Ion Batteries J. Am. Chem. Soc. 2013, 135, 18300– 18303 DOI: 10.1021/ja4100723
  
  208
  Sol-gel design strategy for ultradispersed TiO2 nanoparticles on graphene for high-performance lithium ion batteries
  
  Li, Wei; Wang, Fei; Feng, Shanshan; Wang, Jinxiu; Sun, Zhenkun; Li, Bin; Li, Yuhui; Yang, Jianping; Elzatahry, Ahmed A.; Xia, Yongyao; Zhao, Dongyuan
  
  Journal of the American Chemical Society (2013), 135 (49), 18300-18303CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  The rational design and controllable synthesis of strongly coupled inorg./graphene hybrids represents a long-standing challenge for developing advanced catalysts and energy-storage materials. Here, we report a simple sol-gel method toward creating ultradispersed TiO2 nanoparticles on graphene with an unprecedented degree of control based on the precise sepn. and manipulation of nanoparticles nucleated, grown, anchored, and crystd. and the redn. of graphene oxide (GO). The hybrid materials show ultradispersed anatase nanoparticles (∼5 nm), ultrathin thickness (≤3 layers), and a high surface area of ∼229 m2/g and exhibit a high specific capacity of ∼94 mA h g-1 at ∼59 C, which is twice as that of mech. mixed composites (∼41 mA h g-1), demonstrating the potential of strongly synergistic coupling effects for advanced functional systems.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvVShsLzK&md5=e30dd74a1700a53aea1ce1153fceec9b
209. 209
  Guo, S.; Zhang, S.; Wu, L.; Sun, S. Co/CoO Nanoparticles Assembled on Graphene for Electrochemical Reduction of Oxygen Angew. Chem., Int. Ed. 2012, 51, 11770– 11773 DOI: 10.1002/anie.201206152
  
  209
  Co/CoO Nanoparticles Assembled on Graphene for Electrochemical Reduction of Oxygen
  
  Guo, Shaojun; Zhang, Sen; Wu, Liheng; Sun, Shouheng
  
  Angewandte Chemie, International Edition (2012), 51 (47), 11770-11773CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Authors reported that monodisperse Co/CoO nanoparticles could be presynthesized and deposited on a G surface by the soln.-phase self-assembly method. The formed structure is a high-performance electrocatalyst for the ORR in potassium hydroxide soln. The particle size and interfacial interactions affect the electrocatalytic properties.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsFans7vP&md5=3ed756b9eea505ff4ee0dcf4b62dade9
210. 210
  Duy-Thach, P.; Chung, G. S. A Novel Pd Nanocube-Graphene Hybrid for Hydrogen Detection Sens. Actuators, B 2014, 199, 354– 360 DOI: 10.1016/j.snb.2014.04.013
  
  There is no corresponding record for this reference.
211. 211
  Jabeen, H.; Kemp, K. C.; Chandra, V. Synthesis of Nano Zerovalent Iron Nanoparticles - Graphene Composite for the Treatment of Lead Contaminated Water J. Environ. Manage. 2013, 130, 429– 435 DOI: 10.1016/j.jenvman.2013.08.022
  
  211
  Synthesis of nano zerovalent iron nanoparticles - Graphene composite for the treatment of lead contaminated water
  
  Jabeen, Humera; Kemp, K. Christian; Chandra, Vimlesh
  
  Journal of Environmental Management (2013), 130 (), 429-435CODEN: JEVMAW; ISSN:0301-4797. (Elsevier Ltd.)
  
  A Nano zerovalent iron nanoparticles graphene composite (G-nZVI) was prepd. via a sodium borohydride redn. of graphene oxide and iron chloride under an argon atm. Powder X-ray diffraction patterns showed the formation of the magnetic graphene/nanoscale-zerovalent-iron (G-nZVI) composites and bare nanoscale-zerovalent-iron (nZVI) particles. TEM anal. shows the formation of ∼10 nm particles. Adsorption expts. show a max. Pb(II) adsorption capacity for the G-nZVI composite with 6 wt% graphene oxide loading. Addnl. the effects of pH, temp., contact time, ionic strength and initial metal ion concn. on Pb(II) ion removal were studied. XPS anal. after adsorption results confirmed the composite's ability to adsorb and immobilize lead more efficiently in its zerovalent and bivalent forms, as compared to bare iron nanoparticles. The adsorption of Pb(II) ions fit a pseudo-second-order kinetic model, and adsorption isotherms can be described using the Freundlich equations. G-nZVI shows great potential as an efficient adsorbent for lead immobilization from water, as it exhibits stability, reducing power, a large surface area, and magnetic sepn.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsl2jsLnO&md5=789330e77a7e59880b0fe647427d1d63
212. 212
  Seema, H.; Kemp, K. C.; Chandra, V.; Kim, K. S. Graphene-SnO₂ Composites for Highly Efficient Photocatalytic Degradation of Methylene Blue under Sunlight Nanotechnology 2012, 23, 355705 DOI: 10.1088/0957-4484/23/35/355705
  
  There is no corresponding record for this reference.
213. 213
  Jin, S.; Chen, M.; Dong, H.; He, B.; Lu, H.; Su, L.; Dai, W.; Zhang, Q.; Zhang, X. Stable Silver Nanoclusters Electrochemically Deposited on Nitrogen-Doped Graphene as Efficient Electrocatalyst for Oxygen Reduction Reaction J. Power Sources 2015, 274, 1173– 1179 DOI: 10.1016/j.jpowsour.2014.10.098
  
  213
  Stable silver nanoclusters electrochemically deposited on nitrogen-doped graphene as efficient electrocatalyst for oxygen reduction reaction
  
  Jin, Shi; Chen, Man; Dong, Haifeng; He, Bingyu; Lu, Huiting; Su, Lei; Dai, Wenhao; Zhang, Qiaochu; Zhang, Xueji
  
  Journal of Power Sources (2015), 274 (), 1173-1179CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)
  
  Metal nanoclusters exhibit unusually high catalytic activity toward oxygen redn. reaction (ORR) due to their small size and unique electronic structures. However, controllable synthesis of stable metal nanoclusters is a challenge, and the durability of metal clusters suffers from the deficiency of dissoln., aggregation, and sintering during catalysis reactions. Herein, silver nanoclusters (AgNCs) (diam. < 2 nm) were controllably electrochem. reduced on nitrogen-doped graphene (NG) using effective single-stranded oligonucleotide sequences (ssDNA) as the performed template in absence of any other reluctant. The ssDNA is significant for providing AgNCs with growth template and anchoring the cluster on graphene surface. The strong interaction between the AgNCs, ssDNA and NG renders the as-synthesized AgNCs/NG composite with high-performance onset potential, half-wave potential and mass activity for ORR approaching to com. Pt/C catalyst, and remarkably superior ORR performance than NG and Ag nanoparticle/NG. Importantly, the AgNCs/NG composite shows excellent methanol tolerance and accelerated electrochem. stability (8000 cycles), which is vital in high performance fuel cells, batteries, and nanodevices.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVGhsLfP&md5=2fee5cacd5faca8fb85b0f1139ab407c
214. 214
  Hui, K. S.; Hui, K. N.; Dinh, D. A.; Tsang, C. H.; Cho, Y. R.; Zhou, W.; Hong, X.; Chun, H. H. Green Synthesis of Dimension-Controlled Silver Nanoparticle-Graphene Oxide with in Situ Ultrasonication Acta Mater. 2014, 64, 326– 332 DOI: 10.1016/j.actamat.2013.10.045
  
  214
  Green synthesis of dimension-controlled silver nanoparticle-graphene oxide with in situ ultrasonication
  
  Hui, K. S.; Hui, K. N.; Dinh, D. A.; Tsang, C. H.; Cho, Y. R.; Zhou, Wei; Hong, Xiaoting; Chun, Ho-Hwan
  
  Acta Materialia (2014), 64 (), 326-332CODEN: ACMAFD; ISSN:1359-6454. (Elsevier Ltd.)
  
  A green chem. approach to control the dimensions of Ag nanoparticle-decorated graphene oxide (AgNP-GO) composites was proposed by in situ ultrasonication of a mixt. of AgNO3 and GO soln. with the assistance of vitamin C acting as an environmentally friendly reducing agent at room temp. The AgNP-GO composites were characterized by x-ray diffraction, TEM, energy-dispersive spectroscopy, FTIR, Raman spectra, and UV-visible absorption spectra. Ag nanoparticles with an av. diam. of ≈15 nm were uniformly dispersed on the surface of GO nanosheets by in situ ultrasonication of 1 min with vitamin C. Increasing the ultrasonication times resulted in Ag nanoparticles with tunable dimensions ranging from 15 to 55 nm being formed on the surface of GO nanosheets. The amt. of AgNO3 and the ultrasonication time play a key role in the control of the dimension of Ag nanoparticles on GO, and a formation mechanism of the as-prepd. AgNP-GO composites is proposed. This study provides a guide to controlling the dimensions of AgNP-GO composites, which may hold promise as advanced materials for various anal. applications such as catalysis, sensors, and microchips.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvVWgu7nI&md5=c4d0039fdc9a7d2082134d702e5e338c
215. 215
  Moussa, S.; Siamaki, A. R.; Gupton, B. F.; El-Shall, M. S. Pd-Partially Reduced Graphene Oxide Catalysts (Pd/PRGO): Laser Synthesis of Pd Nanoparticles Supported on PRGO Nanosheets for Carbon-Carbon Cross Coupling Reactions ACS Catal. 2012, 2, 145– 154 DOI: 10.1021/cs200497e
  
  215
  Pd-Partially Reduced Graphene Oxide Catalysts (Pd/PRGO): Laser Synthesis of Pd Nanoparticles Supported on PRGO Nanosheets for Carbon-Carbon Cross Coupling Reactions
  
  Moussa, Sherif; Siamaki, Ali R.; Gupton, B. Frank; El-Shall, M. Samy
  
  ACS Catalysis (2012), 2 (1), 145-154CODEN: ACCACS; ISSN:2155-5435. (American Chemical Society)
  
  This paper reports the development of a new family of highly active Pd nanoparticle catalysts supported on partially reduced graphene oxide nanosheets for carbon-carbon cross-coupling reactions. We report, for the first time, the synthesis of Pd nanoparticle catalysts supported on partially reduced graphene nanosheets (Pd/PRGO) by pulsed laser irradn. of aq. solns. of graphene oxide and palladium ions without the use of chem. reducing or capping agents. The redox reactions initiated by the photoexcitation of GO using two 532 nm photons in different reducing environments of appropriate protic solvents (water, methanol, and ethanol) result in the formation of Pd nanoparticles with different sizes supported on the PRGO nanosheets. The laser irradn. process leads to the formation of multiple defect sites on the surface of the PRGO nanosheets which provide an excellent environment for anchoring the Pd nanoparticles, thus impeding the particles' migration and increasing the catalyst-support interaction. This consequently contributes to the enhanced catalytic performance and recyclability of the catalyst. The Pd/PRGO catalyst generated in water demonstrates excellent catalytic activity for Suzuki, Heck, and Sonogashira cross coupling reactions, with good recyclability for Suzuki coupling with a turn over no. (TON) of 7800 and a remarkable turnover frequency (TOF) of 230,000 h-1 at 120 °C under microwave heating. The results indicate that the defect sites generated on the PRGO nanosheets by the laser photochem. process play a major role in imparting the exceptional catalytic properties to these catalysts.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhsFKkt7zI&md5=9bbf0f80c7958628d06e2f46b0ed9a73
216. 216
  Liu, G.; Wang, Y.; Pu, X.; Jiang, Y.; Cheng, L.; Jiao, Z. One-Step Synthesis of High Conductivity Silver Nanoparticle-Reduced Graphene Oxide Composite Films by Electron Beam Irradiation Appl. Surf. Sci. 2015, 349, 570– 575 DOI: 10.1016/j.apsusc.2015.05.044
  
  There is no corresponding record for this reference.
217. 217
  Haider, M. S.; Badejo, A. C.; Shao, G. N.; Imran, S. M.; Abbas, N.; Chai, Y. G.; Hussain, M.; Kim, H. T. Sequential Repetitive Chemical Reduction Technique to Study Size-Property Relationships of Graphene Attached Ag Nanoparticle Solid State Sci. 2015, 44, 1– 9 DOI: 10.1016/j.solidstatesciences.2015.03.024
  
  217
  Sequential repetitive chemical reduction technique to study size-property relationships of graphene attached Ag nanoparticle
  
  Haider, M. Salman; Badejo, Abimbola Comfort; Shao, Godlisten N.; Imran, S. M.; Abbas, Nadir; Chai, Young Gyu; Hussain, Manwar; Kim, Hee Taik
  
  Solid State Sciences (2015), 44 (), 1-9CODEN: SSSCFJ; ISSN:1293-2558. (Elsevier Masson SAS)
  
  The present study demonstrates a novel, systematic and application route synthesis approach to develop size-property relationship and control the growth of silver nanoparticles (AgNPs) embedded on reduced graphene oxide (rGO). A sequential repetitive chem. redn. technique to observe the growth of silver nanoparticles (AgNPs) attached to rGO, was performed on a single soln. of graphene oxide (GO) and silver nitrate soln. (7 runs, R1-R7) in order to manipulate the growth and size of the AgNPs. The phys.-chem. properties of the samples were examd. by RAMAN, XPS, XRD, SEM-EDAX, and HRTEM analyses. It was confirmed that AgNPs with diam. varying from 4 nm in first run (R1) to 50 nm in seventh run (R7) can be obtained using this technique. A major correlation between particle size and activities was also obsd. Antibacterial activities of the samples were carried out to investigate the disinfection performance of the samples on the Gram neg. bacteria (Escherichia coli). It was suggested that the sample obtained in the third run (R3) exhibited the highest antibacterial activity as compared to other samples, toward disinfection of bacteria due to its superior properties. This study provides a unique and novel application route to synthesize and control size of AgNPs embedded on graphene for various applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXls1Gmurc%253D&md5=96a288ae685d5da229b92688e75c569f
218. 218
  Shi, J.; Zhou, X.; Liu, Y.; Su, Q.; Zhang, J.; Du, G. Sonochemical Synthesis of CuS/Reduced Graphene Oxide Nanocomposites with Enhanced Absorption and Photocatalytic Performance Mater. Lett. 2014, 126, 220– 223 DOI: 10.1016/j.matlet.2014.04.051
  
  218
  Sonochemical synthesis of CuS/reduced graphene oxide nanocomposites with enhanced absorption and photocatalytic performance
  
  Shi, Jingjing; Zhou, Xiaoyan; Liu, Ya; Su, Qingmei; Zhang, Jun; Du, Gaohui
  
  Materials Letters (2014), 126 (), 220-223CODEN: MLETDJ; ISSN:0167-577X. (Elsevier B.V.)
  
  The CuS nanoparticle-decorated reduced graphene oxide (CuS/rGO) composites have been successfully prepd. via a sonochem. method. X-ray diffraction and electron microscopy observations confirm that CuS nanoparticles of 10-25 nm are well distributed on the rGO nanosheets. UV-visible spectroscopy reveals the CuS/rGO nanocomposites show a strong and broad light absorption. Photocatalytic performance of the CuS/rGO nanocomposites is evaluated by measuring the decompn. of methylene blue soln. under natural light. The exptl. results reveal that the as-prepd. nanocomposites show remarkably enhanced photocatalytic activity compared with pure CuS. This can be attributed to the enhanced light adsorption, strong dyestuff absorption, and efficient charge transport after the introduction of rGO.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXotFGlur8%253D&md5=0f87d203145966ae01561618165c3d68
219. 219
  Thangaraju, D.; Karthikeyan, R.; Prakash, N.; Babuc, S. M.; Hayakawa, Y. Growth and Optical Properties of Cu₂ZnSnS₄ Decorated Reduced Graphene Oxide Nanocomposites Dalton Trans. 2015, 44, 15031– 15041 DOI: 10.1039/C5DT01542A
  
  There is no corresponding record for this reference.
220. 220
  Bera, R.; Kundu, S.; Patra, A. 2D Hybrid Nanostructure of Reduced Graphene Oxide-CdS Nanosheet for Enhanced Photocatalysis ACS Appl. Mater. Interfaces 2015, 7, 13251– 13259 DOI: 10.1021/acsami.5b03800
  
  220
  2D Hybrid Nanostructure of Reduced Graphene Oxide-CdS Nanosheet for Enhanced Photocatalysis
  
  Bera, Rajesh; Kundu, Simanta; Patra, Amitava
  
  ACS Applied Materials & Interfaces (2015), 7 (24), 13251-13259CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  Graphene-based hybrid nanostructures have recently emerged as a new class of functional materials for light-energy conversion and storage. Here, we have synthesized reduced graphene oxide (RGO)-semiconductor composites to improve the efficiency of photocatalysis. Zero-dimensional CdS nanoparticles (0D), one-dimensional CdS nanorods (1D), and two-dimensional CdS nanosheets (2D) are grafted on the RGO sheet (2D) by a surface modification method using 4-aminothiophenol (4-ATP). Structural anal. confirms the attachment of CdS nanocrystals with RGO, and the strong electronic interaction is found in the case of a CdS nanosheet and RGO, which has an influence on photocatalytic properties. The degrdn. of dye under visible light varies with changing the dimension of nanocrystals, and the catalytic activity of the CdS NS/RGO composite is ∼4 times higher than that of CdS nanoparticle/RGO and 3.4 times higher than that of CdS nanorod/RGO composite samples. The catalytic activity of the CdS nanosheet/RGO composite is also found to be ∼2.5 times than that of pure CdS nanosheet samples. The unique 2D-2D nanoarchitecture would be effective to harvest photons from solar light and transport electrons to reaction sites with respect to other 0D-2D and 1D-2D hybrid systems. This observation can be extended to other graphene-based inorg. semiconductor composites, which can provide a valuable opportunity to explore novel hybrid materials with superior visible-light-induced catalytic activity.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXpsFarsrY%253D&md5=9dc6dbd82ffae9d7621e63fa4c374bcc
221. 221
  Wang, Z.; Shi, G.; Zhang, F.; Xia, J.; Gui, R.; Yang, M.; Bi, S.; Xia, L.; Li, Y.; Xia, L. Amphoteric Surfactant Promoted Three-Dimensional Assembly of Graphene Micro/Nanoclusters to Accomodate Pt Nanoparticles for Methanol Oxidation Electrochim. Acta 2015, 160, 288– 295 DOI: 10.1016/j.electacta.2015.02.009
  
  221
  Amphoteric surfactant promoted three-dimensional assembly of graphene micro/nanoclusters to accommodate Pt nanoparticles for methanol oxidation
  
  Wang, Zonghua; Shi, Guoyu; Zhang, Feifei; Xia, Jianfei; Gui, Rijun; Yang, Min; Bi, Sai; Xia, Lin; Li, Yanhui; Xia, Linhua; Xia, Yanzhi
  
  Electrochimica Acta (2015), 160 (), 288-295CODEN: ELCAAV; ISSN:0013-4686. (Elsevier Ltd.)
  
  An intelligent amphoteric surfactant (Na lauryl aminopropionate) was introduced to the construction of 3-dimensional graphene micro/nanoclusters, which was used to the synthesis of Pt nanoparticles to obtain the Pt/3D graphene micro/nanocomposite. Owing to the unique pH induced charge transition and micellar arranging property of the amphoteric surfactant, a higher-order assembly of 3-dimensional porous graphene-based architectures from stacked graphene oxide layers can be readily achieved. More importantly, the as-made catalyst Pt/3D graphene exhibits unprecedented activity, excellent CO tolerance and good stability towards MeOH oxidn. which can be attributed to the large surface area, efficient mass transport within the composite and the uniform distribution of small Pt NPs. These outstanding electrochem. properties make Pt/3D graphene a promising catalyst applied in direct MeOH fuel cells.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitVGiur4%253D&md5=d2efcae6613f02e557a90656b19d7fcf
222. 222
  Atar, N.; Eren, T.; Yola, M. L.; Gerengi, H.; Wang, S. Fe@Ag Nanoparticles Decorated Reduced Graphene Oxide as Ultrahigh Capacity Anode Material for Lithium-Ion Battery Ionics 2015, 21, 3185– 3192 DOI: 10.1007/s11581-015-1520-1
  
  222
  Fe@Ag nanoparticles decorated reduced graphene oxide as ultrahigh capacity anode material for lithium-ion battery
  
  Atar, Necip; Eren, Tanju; Yola, Mehmet Lutfi; Gerengi, Husnu; Wang, Shaobin
  
  Ionics (2015), 21 (12), 3185-3192CODEN: IONIFA; ISSN:0947-7047. (Springer)
  
  In the present study, we report the synthesis of Fe@Ag nanoparticles/2-aminoethanethiol functionalized reduced graphene oxide (rGO) composite (Fe@AuNPs-AETrGO) and its application as an improved anode material for lithium-ion batteries (LIBs). The structure of the Fe@AgNPs-AETrGO composite was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), SEM (SEM), and XPS. The electrochem. performance was investigated at different charge/discharge current rates by using CR2032 coin-type cells and cyclic voltammetry (CV). It was found that the spherical Fe@AuNPs were highly dispersed on the rGO sheets. Moreover, the Fe@AuNPs-AETrGO composite showed high specific gravimetric capacity of about 1500 mAh g-1 and long-term cycle stability.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXht1Grtb3L&md5=8caea25359166585cbdb2d6864526523
223. 223
  Fonsaca, J. E. S.; Elias, A. L.; Domingues, S. H.; Oliveira, M. M.; Endo, M.; Orth, E. S.; Terrones, M.; Zarbin, A. J. G. Graphene Nanoribbons Inducing Cube-Shaped Ag Nanoparticle Assemblies Carbon 2015, 93, 800– 811 DOI: 10.1016/j.carbon.2015.05.098
  
  There is no corresponding record for this reference.
224. 224
  Toth, P. S.; Velický, M.; Ramasse, Q. M.; Kepaptsoglou, D. M.; Dryfe, R. A. W. Symmetric and Asymmetric Decoration of Graphene: Bimetal-Graphene Sandwiches Adv. Funct. Mater. 2015, 25, 2899– 2909 DOI: 10.1002/adfm.201500277
  
  224
  Symmetric and Asymmetric Decoration of Graphene: Bimetal-Graphene Sandwiches
  
  Toth, Peter S.; Velicky, Matej; Ramasse, Quentin M.; Kepaptsoglou, Desponia M.; Dryfe, Robert A. W.
  
  Advanced Functional Materials (2015), 25 (19), 2899-2909CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Low-cost, soln. chem.-based, two-step functionalization of an individual, free-standing, chem. vapor-deposited graphene monolayer is reported, with noble metal (Au, Pt, Pd) nanoparticles to build up two-side decorated graphene-based metal nanoclusters. Either the same metal (sym. decoration) or different metals (asym. decoration) are used for the prepn. of bimetal graphene sandwiches, which are adsorbed at the liq./liq. (org./water) interface. The successful fabrication of such dual-decorated graphene-based metal nanocomposites is confirmed using various microscopic techniques (scanning electron and at. force microscopies) and several spectroscopic methods (x-ray photoelectron, energy dispersive x-ray, mapping mode Raman spectra, and electron energy loss spectra). Taken together, it is inferred from these techniques that the location of deposited metal nanoparticles is on opposite sides of the graphene.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsVOit7c%253D&md5=3a9f3175969545019f83e127797785b0
225. 225
  Xiao, F.-X.; Miao, J.; Liu, B. Layer-by-Layer Self-Assembly of CdS Quantum Dots/Graphene Nanosheets Hybrid Films for Photoelectrochemical and Photocatalytic Applications J. Am. Chem. Soc. 2014, 136, 1559– 1569 DOI: 10.1021/ja411651e
  
  225
  Layer-by-Layer Self-Assembly of CdS Quantum Dots/Graphene Nanosheets Hybrid Films for Photoelectrochemical and Photocatalytic Applications
  
  Xiao, Fang-Xing; Miao, Jianwei; Liu, Bin
  
  Journal of the American Chemical Society (2014), 136 (4), 1559-1569CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  In recent years, increasing interest has been devoted to synthesizing graphene-semiconductor nanocomposites as efficient photocatalysts for extensive applications. Unfortunately, it is still challenging to make uniform graphene-semiconductor composite films with controllable film thickness and architecture, which are of paramount importance to meet the application requirements. In this work, stable aq. dispersion of polymer-modified graphene nanosheets (GNs) was prepd. via in situ redn. of exfoliated graphite oxide in the presence of cationic poly-(allylamine hydrochloride) (PAH). The resultant water-sol. PAH-modified GNs (GNs-PAH) in conjunction with tailor-made neg. charged CdS quantum dots (QDs) were utilized as nanobuilding blocks for sequential layer-by-layer (LbL) self-assembly of well-defined GNs-CdS QDs hybrid films, in which CdS QDs overspread evenly on the two-dimensional (2D) GNs. It was found that the alternating GNs-CdS QDs multilayered films showed significantly enhanced photoelectrochem. and photocatalytic activities under visible light irradn. as compared to pure CdS QDs and GNs films. The enhancement was attributed to the judicious integration of CdS QDs with GNs in an alternating manner, which maximizes the 2D structural advantage of GNs in GNs-CdS QDs composite films. In addn., photocatalytic and photoelectrochem. mechanisms of the GNs-CdS QDs multilayered films were also discussed. It is anticipated that our work may open new directions for the fabrication of uniform semiconductor/GNs hybrid films for a wide range of applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjtFagtA%253D%253D&md5=a348c2afb6f8240fd26a58f7721183a4
226. 226
  Zhou, R.; Qiao, S. Z. Silver/Nitrogen-Doped Graphene Interaction and Its Effect on Electrocatalytic Oxygen Reduction Chem. Mater. 2014, 26, 5868– 5873 DOI: 10.1021/cm502260m
  
  226
  Silver/Nitrogen-Doped Graphene Interaction and Its Effect on Electrocatalytic Oxygen Reduction
  
  Zhou, Ruifeng; Qiao, Shi Zhang
  
  Chemistry of Materials (2014), 26 (20), 5868-5873CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)
  
  Three types of silver/reduced graphene oxide (Ag/rGO) nanocomposites (one doped with nitrogen and another two without) are synthesized to investigate their at. structures and the oxygen redn. reaction (ORR) performance with them as the electrocatalysts. For the first time, the bonding interaction between Ag and N in N doped rGO (N-rGO) is confirmed by both high resoln. XPS and surface enhanced Raman spectroscopy (SERS). The Ag/N-rGO shows excellent ORR performance, including very high onset potential and c.d., which outperforms those Ag/rGOs without N doping. Detailed electrochem. anal. shows that the ORR mechanism on Ag/N-rGO is different from both Ag and N-rGO, and its excellent performance is caused by the Ag-N bonding which alters the electronic structure of N-rGO.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1Cit7fI&md5=accdbce9511d7215eabc1498527f5847
227. 227
  Kemp, K. C.; Vimlesh, C.; Muhammad, S.; Kim, K. S. Reversible CO₂ Adsorption by an Activated Nitrogen Doped Graphene/Polyaniline Material Nanotechnology 2013, 24, 235703 DOI: 10.1088/0957-4484/24/23/235703
  
  227
  Reversible CO2 adsorption by an activated nitrogen doped graphene/polyaniline material
  
  Kemp, K. Christian; Chandra, Vimlesh; Saleh, Muhammad; Kim, Kwang S.
  
  Nanotechnology (2013), 24 (23), 235703, 8 pp.CODEN: NNOTER; ISSN:1361-6528. (IOP Publishing Ltd.)
  
  For effective adsorption of carbon dioxide (CO2), we investigate a porous N functionalized graphene adsorbent produced by the chem. activation of a reduced graphene oxide/polyaniline composite. The N-doped graphene composite is microporous with a max. BET surface area of 1336 m2 g-1. It shows a highly reversible max. CO2 storage capacity of 2.7 mmol g-1 at 298 K and 1 atm (5.8 mmol g-1 at 273 K and 1 atm). The N-doped graphene shows good stability during recycling with only an initial decrease of 10% (3-2.7 mmol g-1) in adsorption capacity before attaining a cycling equil. The adsorbance capacity is correlated with N content × pore vol. or N content × surface area. Given that there is no proper correlation parameter, these factors can be used to increase the CO2 adsorption capacity of N-doped graphene materials for practical utility. The as synthesized material also displays selectivity towards CO2 adsorption compared to H2, N2 Ar or CH4. The as formed material shows that graphene can be uniformly N-doped using the presented synthetic method.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht1Gisr%252FL&md5=f1761150aeb45731c638bdc7b755bf03
228. 228
  Park, S.; Hu, Y.; Hwang, J. O.; Lee, E.-S.; Casabianca, L. B.; Cai, W.; Potts, J. R.; Ha, H.-W.; Chen, S.; Oh, J. Chemical Structures of Hydrazine-Treated Graphene Oxide and Generation of Aromatic Nitrogen Doping Nat. Commun. 2012, 3, 638 DOI: 10.1038/ncomms1643
  
  228
  Chemical structures of hydrazine-treated graphene oxide and generation of aromatic nitrogen doping
  
  Park Sungjin; Hu Yichen; Hwang Jin Ok; Lee Eui-Sup; Casabianca Leah B; Cai Weiwei; Potts Jeffrey R; Ha Hyung-Wook; Chen Shanshan; Oh Junghoon; Kim Sang Ouk; Kim Yong-Hyun; Ishii Yoshitaka; Ruoff Rodney S
  
  Nature communications (2012), 3 (), 638 ISSN:.
  
  Chemically modified graphene platelets, produced via graphene oxide, show great promise in a variety of applications due to their electrical, thermal, barrier and mechanical properties. Understanding the chemical structures of chemically modified graphene platelets will aid in the understanding of their physical properties and facilitate development of chemically modified graphene platelet chemistry. Here we use (13)C and (15)N solid-state nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy to study the chemical structure of (15)N-labelled hydrazine-treated (13)C-labelled graphite oxide and unlabelled hydrazine-treated graphene oxide, respectively. These experiments suggest that hydrazine treatment of graphene oxide causes insertion of an aromatic N(2) moiety in a five-membered ring at the platelet edges and also restores graphitic networks on the basal planes. Furthermore, density-functional theory calculations support the formation of such N(2) structures at the edges and help to elucidate the influence of the aromatic N(2) moieties on the electronic structure of chemically modified graphene platelets.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC387otVemug%253D%253D&md5=0538cb797f9e8fcea2034952458aab4f
229. 229
  Marquardt, D.; Beckert, F.; Pennetreau, F.; Tölle, F.; Mülhaupt, R.; Riant, O.; Hermans, S.; Barthel, J.; Janiak, C. Hybrid Materials of Platinum Nanoparticles and Thiol-Functionalized Graphene Derivatives Carbon 2014, 66, 285– 294 DOI: 10.1016/j.carbon.2013.09.002
  
  There is no corresponding record for this reference.
230. 230
  Cui, L.; Wu, J.; Ju, H. Synthesis of Bismuth-Nanoparticle-Enriched Nanoporous Carbon on Graphene for Efficient Electrochemical Analysis of Heavy-Metal Ions Chem. - Eur. J. 2015, 21, 11525– 11530 DOI: 10.1002/chem.201500512
  
  230
  Synthesis of Bismuth-Nanoparticle-Enriched Nanoporous Carbon on Graphene for Efficient Electrochemical Analysis of Heavy-Metal Ions
  
  Cui, Lin; Wu, Jie; Ju, Huangxian
  
  Chemistry - A European Journal (2015), 21 (32), 11525-11530CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A BiNPs@NPCGS nanocomposite was designed for highly efficient detection of multiple heavy-metal ions by in situ synthesis of bismuth-nanoparticle (BiNP)-enriched nanoporous carbon (NPS) on graphene sheet (GS). The NPCGS was prepd. by pyrolysis of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals deposited on graphene oxide and displayed a high surface area of 1251 m2 g-1 and a pore size of 3.4 nm. BiNPs were deposited on NPCGS in situ by chem. redn. of Bi3+ with NaBH4. Due to the restrictive effect of the pore/surface structure of NPCGS, the BiNPs were uniform and well dispersed on the NPCGS. The BiNPs@NPCGS showed good cond. and high effective area, and the presence of BiNPs allowed it to act as an efficient material for anodic-stripping voltammetric detection of heavy-metal ions. Under optimized conditions, the BiNPs@NPCGS-based sensor could simultaneously det. Pb2+ and Cd2+ with detection limits of 3.2 and 4.1 nM, resp. Also, the proposed sensor could also differentiate Tl+ from Pb2+ and Cd2+. Owing to its advantages of simple prepn., environmental friendliness, high surface area, and fast electron-transfer ability, BiNPs@NPCGS showed promise for practical application in sensing heavy-metal ions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtFWgtLfF&md5=d280543df8d640bf5d9e7badc8189129
231. 231
  Wei, W.; Wang, G.; Yang, S.; Feng, X. L.; Mullen, K. Efficient Coupling of Nanoparticles to Electrochemically Exfoliated Graphene J. Am. Chem. Soc. 2015, 137, 5576– 5581 DOI: 10.1021/jacs.5b02284
  
  There is no corresponding record for this reference.
232. 232
  Lee, W. C.; Kim, K.; Park, J.; Koo, J.; Jeong, H. Y.; Lee, H.; Weitz, D. A.; Zettl, A.; Takeuchi, S. Graphene-Templated Directional Growth of an Inorganic Nanowire Nat. Nanotechnol. 2015, 10, 423– 428 DOI: 10.1038/nnano.2015.36
  
  232
  Graphene-templated directional growth of an inorganic nanowire
  
  Lee, Won Chul; Kim, Kwanpyo; Park, Jungwon; Koo, Jahyun; Jeong, Hu Young; Lee, Hoonkyung; Weitz, David A.; Zettl, Alex; Takeuchi, Shoji
  
  Nature Nanotechnology (2015), 10 (5), 423-428CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
  
  Assembling inorg. nanomaterials on graphene is of interest in the development of nanodevices and nanocomposite materials, and the ability to align such inorg. nanomaterials on the graphene surface is expected to lead to improved functionalities, as has previously been demonstrated with org. nanomaterials epitaxially aligned on graphitic surfaces. However, because graphene is chem. inert, it is difficult to precisely assemble inorg. nanomaterials on pristine graphene. Previous techniques based on dangling bonds of damaged graphene, intermediate seed materials, and vapor-phase deposition at high temp. have only formed randomly oriented or poorly aligned inorg. nanostructures. The authors show that inorg. nanowires of gold(I) cyanide can grow directly on pristine graphene, aligning themselves with the zigzag lattice directions of the graphene. The nanowires are synthesized through a self-organized growth process in aq. soln. at room temp., which indicates that the inorg. material spontaneously binds to the pristine graphene surface. First-principles calcns. suggest that this assembly originates from lattice matching and π interaction to gold atoms. Using the synthesized nanowires as templates, the authors also fabricate nanostructures with controlled crystal orientations such as graphene nanoribbons with zigzag-edged directions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlt1aju7c%253D&md5=092c9f786423016721eae622e3116444
233. 233
  Yu, S. U.; Park, B.; Cho, Y.; Hyun, S.; Kim, J. K.; Kim, K. S. Simultaneous Visualization of Graphene Grain Boundaries and Wrinkles with Structural Information by Gold Deposition ACS Nano 2014, 8, 8662– 8668 DOI: 10.1021/nn503550d
  
  233
  Simultaneous visualization of graphene grain boundaries and wrinkles with structural information by gold deposition
  
  Yu, Seong Uk; Park, Beomjin; Cho, Yeonchoo; Hyun, Seung; Kim, Jin Kon; Kim, Kwang S.
  
  ACS Nano (2014), 8 (8), 8662-8668CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Although line defects such as grain boundaries (GBs) and wrinkles are unavoidable in graphene, difficulties in identification preclude studying their impact on electronic and mech. properties. As previous methods focus on a single type of line defect, simultaneous measurements of both GBs and wrinkles with detailed structural information have not been reported. Here, we introduce effective visualization of both line defects by controlled gold deposition. Upon depositing gold on graphene, single lines and double lines of gold nanoparticles (NPs) are formed along GBs and wrinkles, resp. Moreover, it is possible to analyze whether a GB is stitched or overlapped, whether a wrinkle is standing or folded, and the width of the standing collapsed wrinkle. Theor. calcns. show that the characteristic morphol. of gold NPs is due to distinct binding energies of line defects, which are correlated to disrupting diffusion of NPs. Our approach could be further exploited to investigate the defect structures of other two-dimensional materials.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtlequr%252FI&md5=f32ef4b1094a30ff9d1a1aa441c9f6fe
234. 234
  Duong, D. L.; Han, G. H.; Lee, S. M.; Gunes, F.; Kim, E. S.; Kim, S. T.; Kim, H.; Ta, Q. H.; So, K. P.; Yoon, S. J. Probing Graphene Grain Boundaries with Optical Microscopy Nature 2012, 490, 235– 240 DOI: 10.1038/nature11562
  
  234
  Probing graphene grain boundaries with optical microscopy
  
  Duong, Dinh Loc; Han, Gang Hee; Lee, Seung Mi; Gunes, Fethullah; Kim, Eun Sung; Kim, Sung Tae; Kim, Heetae; Ta, Quang Huy; So, Kang Pyo; Yoon, Seok Jun; Chae, Seung Jin; Jo, Young Woo; Park, Min Ho; Chae, Sang Hoon; Lim, Seong Chu; Choi, Jae Young; Lee, Young Hee
  
  Nature (London, United Kingdom) (2012), 490 (7419), 235-239CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)
  
  Grain boundaries in graphene are formed by the joining of islands during the initial growth stage, and these boundaries govern transport properties and related device performance. Although information on the at. rearrangement at graphene grain boundaries can be obtained using transmission electron microscopy and scanning tunneling microscopy, large-scale information regarding the distribution of graphene grain boundaries is not easily accessible. Here we use optical microscopy to observe the grain boundaries of large-area graphene (grown on copper foil) directly, without transfer of the graphene. This imaging technique was realized by selectively oxidizing the underlying copper foil through graphene grain boundaries functionalized with O and OH radicals generated by UV irradn. under moisture-rich ambient conditions: selective diffusion of oxygen radicals through OH-functionalized defect sites was demonstrated by d. functional calcns. The sheet resistance of large-area graphene decreased as the graphene grain sizes increased, but no strong correlation with the grain size of the copper was revealed, in contrast to a previous report. Furthermore, the influence of graphene grain boundaries on crack propagation (initialized by bending) and termination was clearly visualized using our technique. Our approach can be used as a simple protocol for evaluating the grain boundaries of other two-dimensional layered structures, such as boron nitride and exfoliated clays.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsVGjs7%252FO&md5=19116777b7a8451c66f8f06f85eb17e2
235. 235
  Yu, S. U.; Cho, Y.; Park, B.; Kim, N.; Youn, I. S.; Son, M.; Kim, J. K.; Choi, H. C.; Kim, K. S. Fast benchtop visualization of graphene grain boundaries using adhesive properties of defects Chem. Commun. 2013, 49, 5474– 5476 DOI: 10.1039/c3cc42464b
  
  There is no corresponding record for this reference.
236. 236
  Kim, D. W.; Kim, Y. H.; Jeong, H. S.; Jung, H. T. Direct Visualization of Large-Area Graphene Domains and Boundaries by Optical Birefringency Nat. Nanotechnol. 2011, 7, 29– 34 DOI: 10.1038/nnano.2011.198
  
  236
  Direct visualization of large-area graphene domains and boundaries by optical birefringency
  
  Kim Dae Woo; Kim Yun Ho; Jeong Hyeon Su; Jung Hee-Tae
  
  Nature nanotechnology (2011), 7 (1), 29-34 ISSN:.
  
  The boundaries between domains in single-layer graphene strongly influence its electronic properties. However, existing approaches for domain visualization, which are based on microscopy and spectroscopy, are only effective for domains that are less than a few micrometres in size. Here, we report a simple method for the visualization of arbitrarily large graphene domains by imaging the birefringence of a graphene surface covered with nematic liquid crystals. The method relies on a correspondence between the orientation of the liquid crystals and that of the underlying graphene, which we use to determine the boundaries of macroscopic domains.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC387gtlarsg%253D%253D&md5=7120e673a201a9319ad72be86b5bd889
237. 237
  Zhang, H. M.; Yu, X. Z.; Guo, D.; Qu, B. H.; Zhang, M.; Li, Q. H.; Wang, T. H. Synthesis of Bacteria Promoted Reduced Graphene Oxide-Nickel Sulfide Networks for Advanced Supercapacitors ACS Appl. Mater. Interfaces 2013, 5, 7335– 7340 DOI: 10.1021/am401680m
  
  237
  Synthesis of Bacteria Promoted Reduced Graphene Oxide-Nickel Sulfide Networks for Advanced Supercapacitors
  
  Zhang, Haiming; Yu, Xinzhi; Guo, Di; Qu, Baihua; Zhang, Ming; Li, Qiuhong; Wang, Taihong
  
  ACS Applied Materials & Interfaces (2013), 5 (15), 7335-7340CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  Supercapacitors with potential high power are useful and have attracted much attention recently. Graphene-based composites have been demonstrated to be promising electrode materials for supercapacitors with enhanced properties. To improve the performance of graphene-based composites further and realize their synthesis on a large scale, we report a green approach to synthesize bacteria-reduced graphene oxide-nickel sulfide (BGNS) networks. By using Bacillus subtilis as spacers, we deposited reduced graphene oxide/Ni3S2 nanoparticle composites with submillimeter pores directly onto substrate by a binder-free electrostatic spray approach to form BGNS networks. Their electrochem. capacitor performance was evaluated. Compared with stacked reduced graphene oxide-nickel sulfide (GNS) prepd. without the aid of bacteria, BGNS with unique nm-μm structure exhibited a higher specific capacitance of about 1424 F g-1 at a c.d. of 0.75 A g-1. About 67.5% of the capacitance was retained as the c.d. increased from 0.75 to 15 A g-1. At a c.d. of 75 A g-1, a specific capacitance of 406 F g-1 could still remain. The results indicate that the reduced graphene oxide-nickel sulfide network promoted by bacteria is a promising electrode material for supercapacitors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXptFehsLo%253D&md5=b8cd956646d5b1d6a8e6ea4addcca32d
238. 238
  Shi, Y.; Wang, J. Z.; Chou, S. L.; Wexler, D.; Li, H. J.; Ozawa, K.; Liu, H. K.; Wu, Y. P. Hollow Structured Li₃VO₄ Wrapped with Graphene Nanosheets in Situ Prepared by a One-Pot Template-Free Method as an Anode for Lithium-Ion Batteries Nano Lett. 2013, 13, 4715– 4720 DOI: 10.1021/nl402237u
  
  238
  Hollow Structured Li3VO4 Wrapped with Graphene Nanosheets in Situ Prepared by a One-Pot Template-Free Method as an Anode for Lithium-Ion Batteries
  
  Shi, Yi; Wang, Jia-Zhao; Chou, Shu-Lei; Wexler, David; Li, Hui-Jun; Ozawa, Kiyoshi; Liu, Hua-Kun; Wu, Yu-Ping
  
  Nano Letters (2013), 13 (10), 4715-4720CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  To explore good anode materials of high safety, high reversible capacity, good cycling, and excellent rate capability, a Li3VO4 microbox with wall thickness of 40 nm was prepd. by a one-pot and template-free in situ hydrothermal method. In addn., its composite with graphene nanosheets of about six layers of graphene was achieved. Both of them, esp. the Li3VO4/graphene nanosheets composite, show superior electrochem. performance to the formerly reported vanadium-based anode materials. The composite shows a reversible capacity of 223 mA-h/g even at 20C (1C = 400 mA-h/g). After 500 cycles at 10C there is no evident capacity fading.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsVehsrbJ&md5=35229008a631b2539159934b12684aba
239. 239
  Hu, J. T.; Zheng, J. X.; Tian, L. L.; Duan, Y. D.; Lin, L. P.; Cui, S. H.; Peng, H.; Liu, T. C.; Guo, H.; Wang, X. W. A Core-Shell Nanohollow-γ-Fe₂O₃@Graphene Hybrid Prepared through the Kirkendall Process as a High Performance Anode Material for Lithium Ion Batteries Chem. Commun. 2015, 51, 7855– 7858 DOI: 10.1039/C5CC01195G
  
  There is no corresponding record for this reference.
240. 240
  Sengar, S. K.; Mehta, B. R.; Kumar, R.; Singh, V. In-Flight Gas Phase Growth of Metal/Multilayer Graphene Core Shell Nanoparticles with Controllable Sizes Sci. Rep. 2013, 3, 2814 DOI: 10.1038/srep02814
  
  240
  In-flight gas phase growth of metal/multi layer graphene core shell nanoparticles with controllable sizes
  
  Sengar Saurabh K; Mehta B R; Kumar Rakesh; Singh Vinod
  
  Scientific reports (2013), 3 (), 2814 ISSN:.
  
  In this report, we present a general method for a continuous gas-phase synthesis of size-selected metal/multi layer graphene (MLG) core shell nanoparticles having a narrow size distribution of metal core and MLG shell for direct deposition onto any desired substrate kept under clean vacuum conditions. Evolution of MLG signature is clearly observed as the metal-carbon agglomerates get transformed to well defined metal/MLG core shell nanoparticles during their flight through the sintering zone. The growth takes place via an intermediate state of alloy nanoparticle (Pd-carbon) or composite nanoparticle (Cu-carbon), depending upon the carbon solubility in the metal and relative surface energy values. It has been also shown that metal/MLG nanoparticles can be converted to graphene shells. This study will have a large impact on how graphene or graphene based composite nanostructures can be grown and deposited in applications requiring controllable dimensions, varied substrate choice, large area and large scale depositions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2c%252FnsVeksA%253D%253D&md5=9a7cbde5b986c9cb11586ea06b70a9a2
241. 241
  Moon, H.; Kumar, D.; Kim, H.; Sim, C.; Chang, J. H.; Kim, J. M.; Kim, H.; Lim, D. K. Amplified Photoacoustic Performance and Enhanced Photothermal Stability of Reduced Graphene Oxide Coated Gold Nanorods for Sensitive Photo acoustic Imaging ACS Nano 2015, 9, 2711– 2719 DOI: 10.1021/nn506516p
  
  There is no corresponding record for this reference.
242. 242
  Si, Y.; Samulski, E. T. Exfoliated Graphene Separated by Platinum Nanoparticles Chem. Mater. 2008, 20, 6792– 6797 DOI: 10.1021/cm801356a
  
  242
  Exfoliated graphene separated by platinum nanoparticles
  
  Si, Yongchao; Samulski, Edward T.
  
  Chemistry of Materials (2008), 20 (21), 6792-6797CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)
  
  Aggregation of isolated graphene sheets during drying graphene dispersions leads to a loss of its ultrahigh surface area advantage as a 2D nanomaterial. We report a metal nanoparticle-graphene composite with a partially exfoliated graphene morphol. derived from drying aq. dispersions of platinum nanoparticles adhered to graphene. Pt nanoparticles with diams. spanning several nanometers are adhered to graphene by a chem. route involving the redn. of metal precursors in a graphene dispersion. Face-to-face aggregation of graphene sheets is arrested by 3-4 nm fcc Pt crystallites on the graphene surfaces, and in the resulting jammed Pt-graphene composite, the Pt acts as spacers resulting in mech. exfoliated, high-surface-area material of potential interest for supercapacitors and fuel cells.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXht1CgtrvE&md5=cdb49927d288cbe16d95dd0c2b4a80e7
243. 243
  Buglione, L.; Bonanni, A.; Ambrosi, A.; Pumera, M. Gold Nanospacers Greatly Enhance the Capacitance of Electrochemically Reduced Graphene ChemPlusChem 2012, 77, 71– 73 DOI: 10.1002/cplu.201100016
  
  There is no corresponding record for this reference.
244. 244
  Wu, Z.-S.; Ren, W.; Wen, L.; Gao, L.; Zhao, J.; Chen, Z.; Zhou, G.; Li, F.; Cheng, H.-M. Graphene Anchored with Co₃O₄ Nanoparticles as Anode of Lithium IonBatteries with Enhanced Reversible Capacity and Cyclic Performance ACS Nano 2010, 4, 3187– 3194 DOI: 10.1021/nn100740x
  
  There is no corresponding record for this reference.
245. 245
  Liu, Y.; Wang, R.; Yan, X. Synergistic Effect between Ultra-Small Nickel Hydroxide Nanoparticles and Reduced Graphene Oxide Sheets for the Application in High-Performance Asymmetric Supercapacitor Sci. Rep. 2015, 5, 11095 DOI: 10.1038/srep11095
  
  245
  Synergistic Effect between Ultra-Small Nickel Hydroxide Nanoparticles and Reduced Graphene Oxide sheets for the Application in High-Performance Asymmetric Supercapacitor
  
  Liu Yonghuan; Wang Rutao; Yan Xingbin
  
  Scientific reports (2015), 5 (), 11095 ISSN:.
  
  Nanoscale electrode materials including metal oxide nanoparticles and two-dimensional graphene have been employed for designing supercapacitors. However, inevitable agglomeration of nanoparticles and layers stacking of graphene largely hamper their practical applications. Here we demonstrate an efficient co-ordination and synergistic effect between ultra-small Ni(OH)2 nanoparticles and reduced graphene oxide (RGO) sheets for synthesizing ideal electrode materials. On one hand, to make the ultra-small Ni(OH)2 nanoparticles work at full capacity as an ideal pseudocapacitive material, RGO sheets are employed as an suitable substrate to anchor these nanoparticles against agglomeration. As a consequence, an ultrahigh specific capacitance of 1717 F g(-1) at 0.5 A g(-1) is achieved. On the other hand, to further facilitate ion transfer within RGO sheets as an ideal electrical double layer capacitor material, the ultra-small Ni(OH)2 nanoparticles are introduced among RGO sheets as the recyclable sacrificial spacer to prevent the stacking. The resulting RGO sheets exhibit superior rate capability with a high capacitance of 182 F g(-1) at 100 A g(-1). On this basis, an asymmetric supercapacitor is assembled using the two materials, delivering a superior energy density of 75 Wh kg(-1) and an ultrahigh power density of 40 000 W kg(-1).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2Mbhslymuw%253D%253D&md5=dd8fee7c83b21267ca15a7ca6a3b3785
246. 246
  Tiwari, J. N.; Kemp, K. C.; Nath, K.; Tiwari, R. N.; Nam, H.-G.; Kim, K. S. Interconnected Pt-Nanodendrite/DNA/Reduced-Graphene-Oxide Hybrid Showing Remarkable Oxygen Reduction Activity and Stability ACS Nano 2013, 7, 9223– 9231 DOI: 10.1021/nn4038404
  
  246
  Interconnected Pt-Nanodendrite/DNA/Reduced-Graphene-Oxide Hybrid Showing Remarkable Oxygen Reduction Activity and Stability
  
  Tiwari, Jitendra N.; Kemp, Kingsley Christian; Nath, Krishna; Tiwari, Rajanish N.; Nam, Hong-Gil; Kim, Kwang S.
  
  ACS Nano (2013), 7 (10), 9223-9231CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Controlling the morphol. and size of platinum nanodendrites (PtDs) is a key factor in improving their catalytic activity and stability. Here, we report the synthesis is reported of PtDs on genomic-double-stranded-DNA/reduced-graphene-oxide (gdsDNA/rGO) by the NaBH4 redn. of H2PtCl6 in the presence of plant gdsDNA. Compared to industrially adopted catalysts (i.e., state-of-the-art Pt/C catalyst, Pt/rGO, Pt3Co, etc.), the as-synthesized PtDs/gdsDNA/rGO hybrid displays very high oxygen redn. reaction (ORR) catalytic activities (much higher than the 2015 U.S. Department of Energy (DOE) target values), which are the rate-detg. steps in electrochem. energy devices, in terms of onset-potential, half-wave potential, specific-activity, mass-activity, stability, and durability. Moreover, the hybrid exhibits a highly stable mass activity for the ORR over a wide pH range of 1-13. These exceptional properties would make the hybrid applicable in next-generation electrochem. energy devices.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtlKktL7O&md5=cc0d3506d0f584de37fa2ef84aa3eaa7
247. 247
  Tiwari, J. N.; Nath, K.; Kumar, S.; Tiwari, R. N.; Kemp, K. C.; Le, N. H.; Youn, D. H.; Lee, J. S.; Kim, K. S. Stable Platinum Nanoclusters on Genomic DNA-Graphene Oxide with a High Oxygen Reduction Reaction Activity Nat. Commun. 2013, 4, 2221 DOI: 10.1038/ncomms3221
  
  247
  Stable platinum nanoclusters on genomic DNA-graphene oxide with a high oxygen reduction reaction activity
  
  Tiwari Jitendra N; Nath Krishna; Kumar Susheel; Tiwari Rajanish N; Kemp K Christian; Le Nhien H; Youn Duck Hyun; Lee Jae Sung; Kim Kwang S
  
  Nature communications (2013), 4 (), 2221 ISSN:.
  
  Nanosize platinum clusters with small diameters of 2-4 nm are known to be excellent catalysts for the oxygen reduction reaction. The inherent catalytic activity of smaller platinum clusters has not yet been reported due to a lack of preparation methods to control their size (<2 nm). Here we report the synthesis of platinum clusters (diameter ≤1.4 nm) deposited on genomic double-stranded DNA-graphene oxide composites, and their high-performance electrocatalysis of the oxygen reduction reaction. The electrochemical behaviour, characterized by oxygen reduction reaction onset potential, half-wave potential, specific activity, mass activity, accelerated durability test (10,000 cycles) and cyclic voltammetry stability (10,000 cycles) is attributed to the strong interaction between the nanosize platinum clusters and the DNA-graphene oxide composite, which induces modulation in the electronic structure of the platinum clusters. Furthermore, we show that the platinum cluster/DNA-graphene oxide composite possesses notable environmental durability and stability, vital for high-performance fuel cells and batteries.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3sflsVWktw%253D%253D&md5=c1958b96d9871407595cfb085dfbc9fc
248. 248
  Huang, Y. X.; Xie, J. F.; Zhang, X.; Xiong, L.; Yu, H. Q. Reduced Graphene Oxide Supported Palladium Nanoparticles via Photoassisted Citrate Reduction for Enhanced Electrocatalytic Activities ACS Appl. Mater. Interfaces 2014, 6, 15795– 15801 DOI: 10.1021/am504664r
  
  248
  Reduced Graphene Oxide Supported Palladium Nanoparticles via Photoassisted Citrate Reduction for Enhanced Electrocatalytic Activities
  
  Huang, Yu-Xi; Xie, Jia-Fang; Zhang, Xing; Xiong, Lu; Yu, Han-Qing
  
  ACS Applied Materials & Interfaces (2014), 6 (18), 15795-15801CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  Reduced graphene oxide (rGO) supported Pd nanoparticles (Pd NPs) with a size of ∼3 nm were synthesized using 1-pot photoassisted citrate redn. This synthetic approach allows for the formation and assembly of Pd NPs onto the rGO surface with a desired size and can be readily used for other metal NP prepn. The prepd. rGO-Pd exhibited 5.2 times higher mass activity for EtOH oxidn. reaction than the com. Pt/C (Pt/C). In the O redn. reaction tests, rGO-Pd exhibited comparable activity compared with Pt/C and maintained its high performance after 4000 cycles of potential sweep. The authors' synthetic approach is effective for prepg. graphene-supported metal NPs with excellent activity and stability in EtOH oxidn. and O redn. reactions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVWltb7F&md5=29153d13d6d1223a0b7745eea9612efd
249. 249
  Yin, H. J.; Tang, H. J.; Wang, D.; Gao, Y.; Tang, Z. Y. Facile Synthesis of Surfactant-Free Au Cluster/Graphene Hybrids for High-Performance Oxygen Reduction Reaction ACS Nano 2012, 6, 8288– 8297 DOI: 10.1021/nn302984x
  
  249
  Facile Synthesis of Surfactant-Free Au Cluster/Graphene Hybrids for High-Performance Oxygen Reduction Reaction
  
  Yin, Huajie; Tang, Hongjie; Wang, Dan; Gao, Yan; Tang, Zhiyong
  
  ACS Nano (2012), 6 (9), 8288-8297CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Non-Pt noble metal clusters like Au clusters are believed to be promising high performance catalysts for the oxygen redn. reaction (ORR) at the cathode of fuel cells, but they still suffer big problems during the catalysis reactions, such as a large amt. of the capping agents being on the surface and easy occurrence of dissoln. and aggregation. To overcome these obstacles, here, we present a novel and general strategy to grow ultrafine Au clusters and other metal (Pt, Pd) clusters on the reduced graphene oxide (rGO) sheets without any addnl. protecting mol. or reductant. Compared with the currently generally adopted nanocatalysts, including com. Pt/C, rGO sheets, Au nanoparticle/rGO hybrids, and thiol-capped Au clusters of the same sizes, the as-synthesized Au cluster/rGO hybrids display an impressive eletrocatalytic performance toward ORR, for instance, high onset potential, superior methanol tolerance, and excellent stability.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xht1OktLzO&md5=3f492ab4335e1623f45eb7e53cdfd414
250. 250
  Li, Y.; Yu, Y.; Wang, J.-G.; Song, J.; Li, Q.; Dong, M.; Liu, C.-J. CO Oxidation over Graphene Supported Palladium Catalyst Appl. Catal., B 2012, 125, 189– 196 DOI: 10.1016/j.apcatb.2012.05.023
  
  250
  CO oxidation over graphene supported palladium catalyst
  
  Li, Yingzhi; Yu, Yue; Wang, Jian-Guo; Song, Jie; Li, Qiang; Dong, Mingdong; Liu, Chang-Jun
  
  Applied Catalysis, B: Environmental (2012), 125 (), 189-196CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)
  
  Graphene-supported Pd catalyst was prepd. using the conventional impregnation and hydrogen redn. method. Highly dispersed nanoparticles are formed on the support graphene. The DFT study and the catalyst characterization using Raman and XPS confirm that the oxygen contg. groups play an important role in stabilizing Pd clusters on graphene. The first layer of the metal particle mainly presents as PdOx. The graphene supported Pd catalyst shows superior catalytic activity and high stability for CO oxidn. The kinetic studies indicate that CO oxidn. over the graphene supported Pd catalyst follows the Langmuir-Hinshelwood (L-H) mechanism.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhtFCmtrjL&md5=d30209aa9bed4c618602757816521c84
251. 251
  Grayfer, E. D.; Kibis, L. S.; Stadnichenko, A. I.; Vilkov, O. Y.; Boronin, A. I.; Slavinskaya, E. M.; Stonkus, O. A.; Fedorov, V. E. Ultradisperse Pt Nanoparticles Anchored on Defect Sites in Oxygen-Free Few-Layer Graphene and Their Catalytic Properties in CO Oxidation Carbon 2015, 89, 290– 299 DOI: 10.1016/j.carbon.2015.03.050
  
  251
  Ultradisperse Pt nanoparticles anchored on defect sites in oxygen-free few-layer graphene and their catalytic properties in CO oxidation
  
  Grayfer, Ekaterina D.; Kibis, Lidiya S.; Stadnichenko, Andrey I.; Vilkov, Oleg Yu.; Boronin, Andrei I.; Slavinskaya, Elena M.; Stonkus, Olga A.; Fedorov, Vladimir E.
  
  Carbon (2015), 89 (), 290-299CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  Highly uniform and cryst. ultradisperse Pt nanoparticles with av. sizes of 2.4 nm were deposited on oxygen-free few-layer graphene (FLG) by polyol redn. method without any addnl. protective agents. The samples were analyzed by Raman spectroscopy, photoelectron spectroscopy using synchrotron radiation and high-resoln. transmission electron microscopy. The expts. showed that metal nanoparticles were mostly stabilized at defect sites of the FLG support in the absence of oxygen functionalities. Catalytic properties of the samples were tested in CO oxidn. reaction. For Pt nanoparticles forming agglomerates an oscillatory behavior under catalytic reaction conditions was obsd. for the first time for metal-graphene catalysts.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsFGlur4%253D&md5=93f6442f1f0bf85dfd143bc4aa6c8b25
252. 252
  Zhang, C.; Lv, W.; Yang, Q.; Liu, Y. Graphene Supported Nanoparticles of Pt–Ni for CO Oxidation Appl. Surf. Sci. 2012, 258, 7795– 7800 DOI: 10.1016/j.apsusc.2012.03.131
  
  There is no corresponding record for this reference.
253. 253
  Qu, L. T.; Liu, Y.; Baek, J. B.; Dai, L. M. Nitrogen-Doped Graphene as Efficient Metal-Free Electrocatalyst for Oxygen Reduction in Fuel Cells ACS Nano 2010, 4, 1321– 1326 DOI: 10.1021/nn901850u
  
  253
  Nitrogen-Doped Graphene as Efficient Metal-Free Electrocatalyst for Oxygen Reduction in Fuel Cells
  
  Qu, Liangti; Liu, Yong; Baek, Jong-Beom; Dai, Liming
  
  ACS Nano (2010), 4 (3), 1321-1326CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Nitrogen-doped graphene (N-graphene) was synthesized by CVD of methane in the presence of ammonia. The resultant N-graphene was demonstrated to act as a metal-free electrode with a much better electrocatalytic activity, long-term operation stability, and tolerance to crossover effect than platinum for oxygen redn. via a four-electron pathway in alk. fuel cells. This is the 1st report on the use of graphene and its derivs. as metal-free catalysts for oxygen redn. The important role of N-doping to oxygen redn. reaction (ORR) can be applied to various carbon materials for the development of other metal-free efficient ORR catalysts for fuel cell applications, even new catalytic materials for applications beyond fuel cells.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhvFOru7s%253D&md5=f174f231c286b64b62a34ac8d8463732
254. 254
  Yang, Z.; Yao, Z.; Li, G. F.; Fang, G. Y.; Nie, H. G.; Liu, Z.; Zhou, X. M.; Chen, X.; Huang, S. M. Sulfur-Doped Graphene as an Efficient Metal-free Cathode Catalyst for Oxygen Reduction ACS Nano 2012, 6, 205– 211 DOI: 10.1021/nn203393d
  
  254
  Sulfur-Doped Graphene as an Efficient Metal-free Cathode Catalyst for Oxygen Reduction
  
  Yang, Zhi; Yao, Zhen; Li, Guifa; Fang, Guoyong; Nie, Huagui; Liu, Zheng; Zhou, Xuemei; Chen, Xi'an; Huang, Shaoming
  
  ACS Nano (2012), 6 (1), 205-211CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Tailoring the electronic arrangement of graphene by doping is a practical strategy for producing significantly improved materials for the O-redn. reaction (ORR) in fuel cells (FCs). Recent studies proved that the C materials doped with the elements, which have the larger (N) or smaller (P, B) electroneg. atoms than C such as N-doped C nanotubes (CNTs), P-doped graphite layers and B-doped CNTs, also showed pronounced catalytic activity. Herein, the graphenes doped with the elements, which have the similar electronegativity with C such as S and Se, can also exhibit better catalytic activity than the com. Pt/C in alk. media, indicating that these doped graphenes hold great potential for a substitute for Pt-based catalysts in FCs. The exptl. results are believed to be significant because they not only give further insight into the ORR mechanism of these metal-free doped C materials, but also open a way to fabricate other new low-cost NPMCs with high electrocatalytic activity by a simple, economical, and scalable approach for real FC applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhs1OjtbrN&md5=e5861429d3b9a9dbb423b3c96fd22c05
255. 255
  Zhang, C. Z.; Mahmood, N.; Yin, H.; Liu, F.; Hou, Y. L. Synthesis of Phosphorus-Doped Graphene and its Multifunctional Applications for Oxygen Reduction Reaction and Lithium Ion Batteries Adv. Mater. 2013, 25, 4932– 4937 DOI: 10.1002/adma.201301870
  
  255
  Synthesis of Phosphorus-Doped Graphene and its Multifunctional Applications for Oxygen Reduction Reaction and Lithium Ion Batteries
  
  Zhang, Chenzhen; Mahmood, Nasir; Yin, Han; Liu, Fei; Hou, Yanglong
  
  Advanced Materials (Weinheim, Germany) (2013), 25 (35), 4932-4937CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Synthesis of phosphorus-doped graphene and its multifunctional applications for oxygen redn. reaction and lithium ion batteries are discussed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtFelsLvF&md5=efeb096dddd9f1dd78a85d91a3c1495c
256. 256
  Wang, L.; Ambrosi, A.; Pumera, M. ″Metal-Free″ Catalytic Oxygen Reduction Reaction on Heteroatom-Doped Graphene is Caused by Trace Metal Impurities Angew. Chem., Int. Ed. 2013, 52, 13818– 13821 DOI: 10.1002/anie.201309171
  
  There is no corresponding record for this reference.
257. 257
  Wang, L.; Ambrosi, A.; Pumera, M. Could Carbonaceous Impurities in Reduced Graphenes be Responsible for Some of Their Extraordinary Electrocatalytic Activities? Chem. - Asian J. 2013, 8, 1200– 1204 DOI: 10.1002/asia.201300122
  
  257
  Could Carbonaceous Impurities in Reduced Graphenes be Responsible for Some of Their Extraordinary Electrocatalytic Activities?
  
  Wang, Lu; Ambrosi, Adriano; Pumera, Martin
  
  Chemistry - An Asian Journal (2013), 8 (6), 1200-1204CODEN: CAAJBI; ISSN:1861-4728. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Thermally and chem. reduced graphene materials contain significant amts. of carbonaceous impurities that are similar in structure to amorphous carbon. Herein, we show that the claimed electrocatalytic activities of these materials for the oxidn. of NADH, acetaminophen, and hydroquinone are mainly due to the presence of carbonaceous impurities.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXksVKqs74%253D&md5=97a779d8de0502a8f308df0cda641fd5
258. 258
  Yang, J.; Voiry, D.; Ahn, S. J.; Kang, D.; Kim, A. Y.; Chhowalla, M.; Shin, H. S. Two-Dimensional Hybrid Nanosheets of Tungsten Disulfide and Reduced Graphene Oxide as Catalysts for Enhanced Hydrogen Evolution Angew. Chem., Int. Ed. 2013, 52, 13751– 13754 DOI: 10.1002/anie.201307475
  
  258
  Two-Dimensional Hybrid Nanosheets of Tungsten Disulfide and Reduced Graphene Oxide as Catalysts for Enhanced Hydrogen Evolution
  
  Yang, Jieun; Voiry, Damien; Ahn, Seong Joon; Kang, Dongwoo; Kim, Ah Young; Chhowalla, Manish; Shin, Hyeon Suk
  
  Angewandte Chemie, International Edition (2013), 52 (51), 13751-13754CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  The authors develop a hydrothermal method for synthesis of WS2 nanosheets and then integrate rGO nanosheets into the reactor to fabricate novel WS2/rGO hybrids. The authors report detailed structural analyses of the synthesized products and investigate their potential catalysts for the hydrogen evolution reaction (HER). The primary uniqueness of the author's work is the synthesis of WS2 and rGO/WS2 nanosheets using a scalable hydrothermal method and their implementation as efficient catalysts for HER.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslCqsrvJ&md5=eccd15f2fa1a4ede1d674f2c13623cfa
259. 259
  Peng, S. J.; Li, L. L.; Han, X. P.; Sun, W. P.; Srinivasan, M.; Mhaisalkar, S. G.; Cheng, F. Y.; Yan, Q. Y.; Chen, J.; Ramakrishna, S. Cobalt Sulfide Nanosheet/Graphene/Carbon Nanotube Nanocomposites as Flexible Electrodes for Hydrogen Evolution Angew. Chem., Int. Ed. 2014, 53, 12594– 12599 DOI: 10.1002/anie.201408876
  
  259
  Cobalt Sulfide Nanosheet/Graphene/Carbon Nanotube Nanocomposites as Flexible Electrodes for Hydrogen Evolution
  
  Peng, Shengjie; Li, Linlin; Han, Xiaopeng; Sun, Wenping; Srinivasan, Madhavi; Mhaisalkar, Subodh G.; Cheng, Fangyi; Yan, Qingyu; Chen, Jun; Ramakrishna, Seeram
  
  Angewandte Chemie, International Edition (2014), 53 (46), 12594-12599CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Flexible three-dimensional (3D) nanoarchitectures have received tremendous interest recently because of their potential applications in wearable electronics, roll-up displays, and other devices. The design and fabrication of a flexible and robust electrode based on Co sulfide/reduced graphene oxide/C nanotube (CoS2/RGO-CNT) nanocomposites are reported. An efficient hydrothermal process combined with vacuum filtration was used to synthesize such composite architecture, which was then embedded in a porous CNT network. This conductive and robust film is evaluated as electrocatalyst for the H evolution reaction. The synergistic effect of CoS2, graphene, and CNTs leads to unique CoS2/RGO-CNT nanoarchitectures, the HER activity of which is among the highest for nonnoble metal electrocatalysts, showing 10 mA cm-2 c.d. at ∼142 mV overpotentials and a high electrochem. stability.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVGksL3I&md5=87d21c61b035f47a0ae920bfa4f3c53a
260. 260
  He, C. Y.; Tao, J. Z. Synthesis of Nanostructured Clean Surface Molybdenum Carbides on Graphene Sheets as Efficient and Stable Hydrogen Evolution Reaction Catalysts Chem. Commun. 2015, 51, 8323– 8325 DOI: 10.1039/C5CC01240F
  
  260
  Synthesis of nanostructured clean surface molybdenum carbides on graphene sheets as efficient and stable hydrogen evolution reaction catalysts
  
  He, Chunyong; Tao, Juzhou
  
  Chemical Communications (Cambridge, United Kingdom) (2015), 51 (39), 8323-8325CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)
  
  Small size molybdenum carbides (2.5 nm for MoC and 5.0 nm for Mo2C) with clean surface on graphene were prepd. for efficient and stable hydrogen evolution reaction catalysts.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmt1Wrtbs%253D&md5=77e4a8dd5bc8ba3c57d1722d310431de
261. 261
  Youn, D. H.; Han, S.; Kim, J. Y.; Kim, J. Y.; Park, H.; Choi, S. H.; Lee, J. S. Highly Active and Stable Hydrogen Evolution Electrocatalysts Based on Molybdenum Compounds on Carbon Nanotube-Graphene Hybrid Support ACS Nano 2014, 8, 5164– 5173 DOI: 10.1021/nn5012144
  
  261
  Highly Active and Stable Hydrogen Evolution Electrocatalysts Based on Molybdenum Compounds on Carbon Nanotube-Graphene Hybrid Support
  
  Youn, Duck Hyun; Han, Suenghoon; Kim, Jae Young; Kim, Jae Yul; Park, Hunmin; Choi, Sun Hee; Lee, Jae Sung
  
  ACS Nano (2014), 8 (5), 5164-5173CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Highly active and stable electrocatalysts for H evolution were developed from Mo compds. (Mo2C, Mo2N, and MoS2) on C nanotube (CNT)-graphene hybrid support via a modified urea-glass route. By a simple modification of synthetic variables, the final phases are easily controlled from carbide, nitride to sulfide with homogeneous dispersion of nanocrystals on the CNT-graphene support. Among the prepd. catalysts, Mo2C/CNT-graphene shows the highest activity for H evolution reaction with a small onset overpotential of 62 mV and Tafel slope of 58 mV/dec as well as an excellent stability in acid media. Such enhanced catalytic activity may originate from its low H binding energy and high cond. Also, the CNT-graphene hybrid support plays crucial roles to enhance the activity of Mo compds. by alleviating aggregation of the nanocrystals, providing a large area to contact with electrolyte, and facilitating the electron transfer.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXntFOmsbc%253D&md5=7feb6394caf9da2b6dd8ddd3468f7667
262. 262
  Bai, S.; Wang, C. M.; Deng, M. S.; Gong, M.; Bai, Y.; Jiang, J.; Xiong, Y. J. Surface Polarization Matters: Enhancing the Hydrogen-Evolution Reaction by Shrinking Pt Shells in Pt-Pd-Graphene Stack Structures Angew. Chem., Int. Ed. 2014, 53, 12120– 12124 DOI: 10.1002/anie.201406468
  
  262
  Surface Polarization Matters: Enhancing the Hydrogen-Evolution Reaction by Shrinking Pt Shells in Pt-Pd-Graphene Stack Structures
  
  Bai, Song; Wang, Chengming; Deng, Mingsen; Gong, Ming; Bai, Yu; Jiang, Jun; Xiong, Yujie
  
  Angewandte Chemie, International Edition (2014), 53 (45), 12120-12124CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Surface charge state plays an important role in tuning the catalytic performance of nanocrystals in various reactions. Herein, we report a synthetic approach to unique Pt-Pd-graphene stack structures with controllable Pt shell thickness. These unique hybrid structures allow us to correlate the Pt thickness with performance in the hydrogen-evolution reaction (HER). The HER activity increases with a decrease in the Pt thickness, which is well explained by surface polarization mechanism as suggested by first-principles simulations. In this hybrid system, the difference in work functions of Pt and Pd results in surface polarization on the Pt surface, tuning its charge state for hydrogen redn. Meanwhile, the supporting graphene provides two-dimensional channels for efficient charge transport, improving the HER activities. This work opens up possibilities of reducing Pt usage while achieving high HER performance.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVWqtrzK&md5=8e95fea009b267349957bd038b98d296
263. 263
  Yan, H. J.; Tian, C. G.; Wang, L.; Wu, A. P.; Meng, M. C.; Zhao, L.; Fu, H. G. Phosphorus-Modified Tungsten Nitride/Reduced Graphene Oxide as a High-Performance, Non-Noble-Metal Electrocatalyst for the Hydrogen Evolution Reaction Angew. Chem., Int. Ed. 2015, 54, 6325– 6329 DOI: 10.1002/anie.201501419
  
  263
  Phosphorus-Modified Tungsten Nitride/Reduced Graphene Oxide as a High-Performance, Non-Noble-Metal Electrocatalyst for the Hydrogen Evolution Reaction
  
  Yan, Haijing; Tian, Chungui; Wang, Lei; Wu, Aiping; Meng, Meichen; Zhao, Lu; Fu, Honggang
  
  Angewandte Chemie, International Edition (2015), 54 (21), 6325-6329CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Phosphorus-modified tungsten nitride/reduced graphene oxide (P-WN/rGO) is designed as a highly-efficient, low-cost electrocatalyst for the hydrogen evolution reaction (HER). WN (ca. 3 nm in size) on rGO is first synthesized by using the H3[PO4(W3O9)4] cluster as a W source. Followed by phosphorization, the particle size increase slightly to about 4 nm with a P content of 2.52 at.%. The interaction of P with rGO and WN results in an obvious increase of work function, being close to Pt metal. The P-WN/rGO exhibits low onset overpotential of 46 mV, Tafel slope of 54 mV dec-1, and a large exchange c.d. of 0.35 mA cm-2 in acid media. It requires overpotential of only 85 mV at c.d. of 10 mA cm-2, while remaining with good stability in accelerated durability testing. This work shows that the modification with a second anion is powerful way to design new catalysts for HER.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsVOgs78%253D&md5=15991192dc2f01287254838efe1cf19d
264. 264
  Chen, Y.; Zhu, Q. L.; Tsumori, N.; Xu, Q. Immobilizing Highly Catalytically Active Noble Metal Nanoparticles on Reduced Graphene Oxide: A Non-Noble Metal Sacrificial Approach J. Am. Chem. Soc. 2015, 137, 106– 109 DOI: 10.1021/ja511511q
  
  264
  Immobilizing Highly Catalytically Active Noble Metal Nanoparticles on Reduced Graphene Oxide: A Non-Noble Metal Sacrificial Approach
  
  Chen, Yao; Zhu, Qi-Long; Tsumori, Nobuko; Xu, Qiang
  
  Journal of the American Chemical Society (2015), 137 (1), 106-109CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  In this work, we have developed a non-noble metal sacrificial approach for the first time to successfully immobilize highly dispersed AgPd nanoparticles on reduced graphene oxide (RGO). The Co3(BO3)2 co-pptd. with AgPd nanoparticles and subsequently sacrificed by acid etching effectively prevents the primary AgPd particles from aggregation. The resulted ultrafine AgPd nanoparticles exhibit the highest activity (turnover frequency, 2739 h-1 at 323 K) among all the heterogeneous catalysts for the dehydrogenation of formic acid to generate hydrogen without CO impurity. The sacrificial approach opens up a new avenue for the development of high-performance metal nanocatalysts.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFyhtLrK&md5=b9c1dbe93d61d70cd9a0c5ebe2f1f118
265. 265
  Yang, J. M.; Wang, S. A.; Sun, C. L.; Ger, M. D. Synthesis of size-selected Pt Nanoparticles Supported on Sulfonated Graphene with Polyvinyl Alcohol for Methanol Oxidation in Alkaline Solutions J. Power Sources 2014, 254, 298– 305 DOI: 10.1016/j.jpowsour.2013.12.120
  
  265
  Synthesis of size-selected Pt nanoparticles supported on sulfonated graphene with polyvinyl alcohol for methanol oxidation in alkaline solutions
  
  Yang, Jen-Ming; Wang, Sheng-An; Sun, Chia-Liang; Ger, Ming-Der
  
  Journal of Power Sources (2014), 254 (), 298-305CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)
  
  The size-selected platinum (Pt) nanoparticles are loaded on sulfonated graphene with polyvinyl alc. (PVA) as the conductive polymer for fuel-cell applications. Methanol oxidn. reactions and reliability of various catalysts based on carbon black, graphene, and sulfonated graphene catalyst supports are compared under alk. conditions. When PVA is used as the conductive polymer in place of Nafion, both the electrochem. active surface area (ECSA) and the methanol oxidn. property were superior, irresp. of the catalyst and support. However, the catalyst with Pt on sulfonated graphene (Pt/sG) outperforms those on other supports. For methanol oxidn., the catalyst decay occurs with a decay of only 9.06% for Pt/sG. Probably the sulfonate functional group on graphene not only improves catalytic activity but can also enhance catalyst reliability.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFOku7w%253D&md5=5d87d12390a7ef6c097ef84d9a2fa3c3
266. 266
  Chen, Y.; Yang, J.; Yang, Y.; Peng, Z.; Li, J.; Mei, T.; Wang, J.; Hao, M.; Chen, Y.; Xiong, W. A Facile Strategy to Synthesize Three-Dimensional Pd@Pt Core-Shell Nanoflowers Supported on Graphene Nanosheets as Enhanced Nanoelectrocatalysts for Methanol Oxidation Chem. Commun. 2015, 51, 10490– 10493 DOI: 10.1039/C5CC01803J
  
  266
  A facile strategy to synthesize three-dimensional Pd@Pt core-shell nanoflowers supported on graphene nanosheets as enhanced nanoelectrocatalysts for methanol oxidation
  
  Chen, Yi; Yang, Jia; Yang, Ying; Peng, Zhiyao; Li, Jinhua; Mei, Tao; Wang, Jianying; Hao, Ming; Chen, Yalin; Xiong, Weilai; Zhang, Liu; Wang, Xianbao
  
  Chemical Communications (Cambridge, United Kingdom) (2015), 51 (52), 10490-10493CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)
  
  Here the authors demonstrate for the 1st time a H2O-based surfactant-free synthesis of 3-dimensional porous Pd@Pt core-shell nanoflowers on graphene. The obtained Pd@Pt-graphene hybrids exhibited substantially enhanced electrocatalytic activity and stability relative to the com. Pt/C catalyst originating from this exquisite nanoarchitecture for 3-dimensional mol. accessibility and graphene-metal interaction.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnsVehsr4%253D&md5=983e2b6ceef3e13282424acacf4f5bcc
267. 267
  Metin, O.; Ho, S. F.; Alp, C.; Can, H.; Mankin, M. N.; Gultekin, M. S.; Chi, M. F.; Sun, S. H. Ni/Pd Core/Shell Nanoparticles Supported on Graphene as a Highly Active and Reusable Catalyst for Suzuki-Miyaura Cross-Coupling Reaction Nano Res. 2013, 6, 10– 18 DOI: 10.1007/s12274-012-0276-4
  
  267
  Ni/Pd core/shell nanoparticles supported on graphene as a highly active and reusable catalyst for Suzuki-Miyaura cross-coupling reaction
  
  Metin, Oender; Ho, Sally Fae; Alp, Cemalettin; Can, Hasan; Mankin, Max N.; Gueltekin, Mehmet Serdar; Chi, Miaofang; Sun, Shouheng
  
  Nano Research (2013), 6 (1), 10-18CODEN: NRAEB5; ISSN:1998-0000. (Springer GmbH)
  
  Monodisperse Ni/Pd core/shell nanoparticles (NPs) have been synthesized by sequential redn. of nickel(II) acetate and palladium(II) bromide in oleylamine (OAm) and trioctylphosphine (TOP). The Ni/Pd NPs have a narrow size distribution with a mean particle size of 10 nm and a std. deviation of 5% with respect to the particle diam. Mechanistic studies showed that the presence of TOP was essential to control the reductive decompn. of Ni-TOP and Pd-TOP, and the formation of Ni/Pd core/shell NPs. Using the current synthetic protocol, the compn. of the Ni/Pd within the core/shell structure can be readily tuned by simply controlling the initial molar ratio of the Ni and Pd salts. The as-synthesized Ni/Pd core/shell NPs were supported on graphene (G) and used as catalyst in Suzuki-Miyaura cross-coupling reactions. Among three different kinds of Ni/Pd NPs tested, the Ni/Pd (Ni/Pd = 3/2) NPs were found to be the most active catalyst for the Suzuki-Miyaura cross-coupling of arylboronic acids with aryl iodides, bromides and even chlorides in a dimethylformamide/water mixt. by using K2CO3 as a base at 110 °C. The G-Ni/Pd was also stable and reusable, providing 98% conversion after the 5th catalytic run without showing any noticeable Ni/Pd compn. change. The G-Ni/Pd structure reported in this paper combines both the efficiency of a homogeneous catalyst and the durability of a heterogeneous catalyst, and is promising catalyst candidate for various Pd-based catalytic applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtFWrtrc%253D&md5=ea6aa6b18fce78babd184c461e4062bc
268. 268
  Putta, C.; Sharavath, V.; Sarkar, S.; Ghosh, S. Palladium Nanoparticles on Beta-Cyclodextrin Functionalised Graphene Nanosheets: A Supramolecular Based Heterogeneous Catalyst for C-C Coupling Reactions under Green Reaction Conditions RSC Adv. 2015, 5, 6652– 6660 DOI: 10.1039/C4RA14323J
  
  268
  Palladium nanoparticles on β-cyclodextrin functionalised graphene nanosheets: a supramolecular based heterogeneous catalyst for C-C coupling reactions under green reaction conditions
  
  Putta, Chandrababu; Sharavath, Vittal; Sarkar, Suprabhat; Ghosh, Sutapa
  
  RSC Advances (2015), 5 (9), 6652-6660CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  The use of functional properties of native cyclodextrins in palladium nanoparticle-β-cyclodextrin-graphene nanosheet (Pd@CD-GNS) catalyzed carbon-carbon (C-C) coupling reactions have been investigated under green reaction conditions. The supramol. catalyst was prepd. by deposition of Pd nanoparticles (Pd NPs) on CD-GNS using ethanol as the greener solvent and in situ reducing agent. The catalytic activity of these catalysts is investigated in C-C coupling reactions such as Suzuki-Miyaura and Heck-Mizoroki reactions of aryl bromides 4-RC6H4Br (R = OH, t-Bu, NO2, etc.) and aryl chlorides R1Cl (R1 = C6H5, 4-HOC6H4, 2-pyridyl, etc.) with boronic acids R2B(OH)2 (R2 = C6H5, 4-O2NC6H4) and alkenes R3HC=CH2 [R3 = C(O)2H, C(O)2Me, C(O)2t-Bu, Ph] resp., under green reaction conditions i.e. in water, under phosphine free and aerobic conditions. This catalyst afforded excellent selectivities for the products in good to excellent yields under low Pd loadings (0.2-0.05 mol%), while ensuring the recovery and reusability of the catalysts. The CD supramol. mediators loaded on GNS act as stabilizing agents for the Pd NPs. The excellent catalytic activity of this system was attributed to the presence of CDs, excellent dispersibility in water, hydrophobic nature of the GNS support for the accumulation of org. substrates in water, "Breslow effect", the presence of PTC to overcome the mass transfer limitation onto the surface of GNS and formation of ternary CD/substrate/additive complexes on the Pd-GNS surface.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFehu7rI&md5=cbfee2b0031cf10cab50bbb4937b86a1
269. 269
  Ren, L.; Yang, F.; Wang, C. X.; Li, Y. F.; Liu, H. L.; Tu, Z. Q.; Zhang, L. Q.; Liu, Z. C.; Gao, J. S.; Xu, C. M. Plasma Synthesis of Oxidized Graphene Foam Supporting Pd Nanoparticles as a New Catalyst for One-Pot Synthesis of Dibenzyls RSC Adv. 2014, 4, 63048– 63054 DOI: 10.1039/C4RA11060A
  
  269
  Plasma synthesis of oxidized graphene foam supporting Pd nanoparticles as a new catalyst for one-pot synthesis of dibenzyls
  
  Ren, Liang; Yang, Fan; Wang, Chunxia; Li, Yongfeng; Liu, Hailing; Tu, Zhiqiang; Zhang, Liqiang; Liu, Zhichang; Gao, Jinsen; Xu, Chunming
  
  RSC Advances (2014), 4 (108), 63048-63054CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  An environmentally-friendly method for the synthesis of Pd nanoparticle (Pd NPs) decorated different graphene supports has been developed, and the morphol. and structure of the hybrids are characterized by transmission electron microscopy, X-ray diffraction, XPS and elemental mappings. Four hybrid materials based on graphene foam (GF), oxidized graphene foam (OGF), graphene oxide (GO) and reduced graphene oxide (RGO) have been used to catalyze Heck coupling reactions, and the effect of support on the activity of the hybrid material has been studied. It was revealed that Pd NP decorated OGF (Pd/OGF) is the most active catalyst, showing better performance than the com. Pd/C catalyst. More importantly, the Pd/OGF catalyst has been successfully used for one-pot synthesis of dibenzyls RC6H4CH2CH2R1 [R = H, CH3, C(O)CH3, OCH3, Cl; R1 = C6H5, CO2CH2CH3] with different aryl bromides RC6H4Br and olefins CH2=CHR1, which has simplified the sepn. and purifn. process and realized a green org. synthesis process.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvF2lurrF&md5=e037183eeddefe0526e327f5d74ec87e
270. 270
  Fang, Y. X.; Wang, E. K. Electrochemical Biosensors on Platforms of Graphene Chem. Commun. 2013, 49, 9526– 9539 DOI: 10.1039/c3cc44735a
  
  270
  Electrochemical biosensors on platforms of graphene
  
  Fang, Youxing; Wang, Erkang
  
  Chemical Communications (Cambridge, United Kingdom) (2013), 49 (83), 9526-9539CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)
  
  A review. In recent years, graphene, the two-dimensional closely packed honeycomb carbon lattice, has been attracting much attention in the field of electrochem. due to its intrinsic properties and merits. Efforts to create novel graphene based electrochem. biosensors have led to the establishment of effective strategies for diverse bioassays, from simple mols. to complex biotargets. In this Feature Article, we provide an overview of electrochem. biosensing with graphene related materials, and discuss the role of graphene in different sensing protocols.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFWksLnL&md5=b92ceb429ffd2784bb296c943f4820dd
271. 271
  Wu, W.; Liu, Z. H.; Jauregui, L. A.; Yu, Q. K.; Pillai, R.; Cao, H. L.; Bao, J. M.; Chen, Y. P.; Pei, S. S. Wafer-Scale Synthesis of Graphene by Chemical Vapor Deposition and Its Application in Hydrogen Sensing Sens. Actuators, B 2010, 150, 296– 300 DOI: 10.1016/j.snb.2010.06.070
  
  271
  Wafer-scale synthesis of graphene by chemical vapor deposition and its application in hydrogen sensing
  
  Wu, Wei; Liu, Zhihong; Jauregui, Luis A.; Yu, Qingkai; Pillai, Rajeev; Cao, Helin; Bao, Jiming; Chen, Yong P.; Pei, Shin-Shem
  
  Sensors and Actuators, B: Chemical (2010), 150 (1), 296-300CODEN: SABCEB; ISSN:0925-4005. (Elsevier B.V.)
  
  Graphene with a large area was prepd. on Cu foils by chem. vapor deposition under ambient pressure. A 4'' × 4'' graphene film was transferred onto a 6'' Si wafer with a thermally grown oxide film. Raman mapping indicates monolayer graphene dominates the transferred graphene film. Gas sensors were fabricated on a 4 mm × 3 mm size graphene film with a 1 nm Pd film deposited for hydrogen detection. H2 in air with concns. in 0.0025-1% (25-10,000 ppm) was used to test graphene-based gas sensors. The gas sensors based on Pd-decorated graphene films show high sensitivity, fast response and recovery, and can be used with multiple cycles. The mechanism of hydrogen detection is also discussed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtFChsb%252FF&md5=a105f9dbbaeb01397d3d32344b9dc8ad
272. 272
  Li, M.; Bo, X. J.; Zhang, Y. F.; Han, C.; Guo, L. P. One-Pot Ionic Liquid-Assisted Synthesis of Highly Dispersed PtPd Nanoparticles/Reduced Graphene Oxide Composites for Nonenzymatic Glucose Detection Biosens. Bioelectron. 2014, 56, 223– 230 DOI: 10.1016/j.bios.2014.01.030
  
  272
  One-pot ionic liquid-assisted synthesis of highly dispersed PtPd nanoparticles/reduced graphene oxide composites for nonenzymatic glucose detection
  
  Li, Mian; Bo, Xiangjie; Zhang, Yufan; Han, Ce; Guo, Liping
  
  Biosensors & Bioelectronics (2014), 56 (), 223-230CODEN: BBIOE4; ISSN:0956-5663. (Elsevier B.V.)
  
  A series of highly dispersed bimetallic PtPd alloy nanoparticles (NPs) anchored on reduced graphene oxide (RGO) have been synthesized with the assistance of ionic liq. (IL: [VEIM]BF4). Different ratios of (PtCl6)2- and (PdCl4)2- ions were firstly attached to IL functionalized graphene oxide (GO) sheets in ethylene glycol (EG), and then the encased metal ions and graphene oxide sheets were reduced simultaneously by EG with the assistance of microwave. The characterization results of SEM (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), XPS, Raman spectroscopy, and X-ray diffraction (XRD) demonstrate that PtPd alloy NPs with small particle sizes are uniformly dispersed on RGO. Electrochem. measurements reveal that PtPd-IL-RGO modified electrode can directly catalyze glucose oxidn. and display enhanced current response compared with PtPd-RGO (such as: a response time within 3 s, a linear range from 0.1 to 22 mM at 0 V, good reproducibility, considerable stability, and excellent anti-interference to electroactive mols. and Cl-). The superior catalytic activity and selectivity make PtPd-IL-RGO nanomaterials very promising for applications in direct detection of glucose.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjsVajsLo%253D&md5=9f05ded8ade2b47585848222dc183fea
273. 273
  Mukherji, A.; Seger, B.; Lu, G. Q.; Wang, L. Z. Nitrogen Doped Sr₂Ta₂O₇ Coupled with Graphene Sheets as Photocatalysts for Increased Photocatalytic Hydrogen Production ACS Nano 2011, 5, 3483– 3492 DOI: 10.1021/nn102469e
  
  273
  Nitrogen Doped Sr2Ta2O7 Coupled with Graphene Sheets as Photocatalysts for Increased Photocatalytic Hydrogen Production
  
  Mukherji, Aniruddh; Seger, Brian; Lu, Gao Qing; Wang, Lianzhou
  
  ACS Nano (2011), 5 (5), 3483-3492CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  In this work we present the synthesis of a new type of N-doped tantalate, Sr2Ta2O7-xNx, which exhibited significantly increased visible light absorption and improved photocatalytic H prodn. by 87% under solar irradn., compared with its undoped counterpart Sr2Ta2O7. The photocatalyst also exhibited a strong capability in photoinduced redn. of exfoliated graphene oxide (GO) to graphene sheets. By using graphene as a support for a Pt cocatalyst, a new type of composite contg. graphene-Pt and Sr2Ta2O7-xNx was designed, which demonstrated an addnl. ∼80% increase in H prodn. and an quantum efficiency of 6.45% (∼177% increase from pristine undoped Sr2Ta2O7) due to the efficient charge carrier sepn. on the photocatalyst. Probably graphene can play an important role as an electron transfer highway, which facilitates the charge carrier collection onto Pt co-catalysts. The method can thus be considered as an excellent strategy to increase photocatalytic H prodn. in addn. to a commonly applied doping method.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXkvVOqtb8%253D&md5=f405bbb5e72bc6a14135299a8951f934
274. 274
  Li, Q.; Guo, B. D.; Yu, J. G.; Ran, J. R.; Zhang, B. H.; Yan, H. J.; Gong, J. R. Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Production of CdS-Cluster-Decorated Graphene Nanosheets J. Am. Chem. Soc. 2011, 133, 10878– 10884 DOI: 10.1021/ja2025454
  
  274
  Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Production of CdS-Cluster-Decorated Graphene Nanosheets
  
  Li, Qin; Guo, Beidou; Yu, Jiaguo; Ran, Jingrun; Zhang, Baohong; Yan, Huijuan; Gong, Jian Ru
  
  Journal of the American Chemical Society (2011), 133 (28), 10878-10884CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  The prodn. of clean and renewable H through H2O splitting using photocatalysts has received much attention due to the increasing global energy crises. A high efficiency of the photocatalytic H2 prodn. was achieved using graphene nanosheets decorated with CdS clusters as visible-light-driven photocatalysts. The materials were prepd. by a solvothermal method in which graphene oxide (GO) served as the support and Cd acetate (Cd(Ac)2) as the CdS precursor. These nanosized composites reach a high H2-prodn. rate of 1.12 mmol h-1 (∼4.87 times higher than that of pure CdS nanoparticles) at graphene content of 1.0% and Pt 0.5% under visible-light irradn. and an apparent quantum efficiency (QE) of 22.5% at wavelength of 420 nm. This high photocatalytic H2-prodn. activity is attributed predominantly to the presence of graphene, which serves as an electron collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carriers from CdS nanoparticles. This work highlights the potential application of graphene-based materials in the field of energy conversion.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXnvFahu78%253D&md5=56a74c1ff602be77bf55bd04f961eb71
275. 275
  Meng, F. K.; Li, J. T.; Cushing, S. K.; Zhi, M. J.; Wu, N. Q. Solar Hydrogen Generation by Nanoscale p-n Junction of p-type Molybdenum Disulfide/n-type Nitrogen-Doped Reduced Graphene Oxide J. Am. Chem. Soc. 2013, 135, 10286– 10289 DOI: 10.1021/ja404851s
  
  275
  Solar Hydrogen Generation by Nanoscale p-n Junction of p-type Molybdenum Disulfide/n-type Nitrogen-Doped Reduced Graphene Oxide
  
  Meng, Fanke; Li, Jiangtian; Cushing, Scott K.; Zhi, Mingjia; Wu, Nianqiang
  
  Journal of the American Chemical Society (2013), 135 (28), 10286-10289CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  Molybdenum disulfide (MoS2) is a promising candidate for solar hydrogen generation but it alone has negligible photocatalytic activity. 5-20 Nm sized p-type MoS2 nanoplatelets are deposited on the n-type nitrogen-doped reduced graphene oxide (n-rGO) nanosheets to form multiple nanoscale p-n junctions in each rGO nanosheet. The p-MoS2/n-rGO heterostructure shows significant photocatalytic activity toward the hydrogen evolution reaction (HER) in the wavelength range from the UV light through the near-IR light. The photoelectrochem. measurement shows that the p-MoS2/n-rGO junction greatly enhances the charge generation and suppresses the charge recombination, which is responsible for enhancement of solar hydrogen generation. The p-MoS2/n-rGO is an earth-abundant and environmentally benign photocatalyst for solar hydrogen generation.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtValsbbM&md5=f897a91942a5538557e2b1c28d3a9211
276. 276
  Wang, Y.; Yu, J. G.; Xiao, W.; Li, Q. Microwave-Assisted Hydrothermal Synthesis of Graphene Based Au-TiO₂ Photocatalysts for Efficient Visible-Light Hydrogen Production J. Mater. Chem. A 2014, 2, 3847– 3855 DOI: 10.1039/c3ta14908k
  
  276
  Microwave-assisted hydrothermal synthesis of graphene based Au-TiO2 photocatalysts for efficient visible-light hydrogen production
  
  Wang, Ying; Yu, Jiaguo; Xiao, Wei; Li, Qin
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (11), 3847-3855CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  The construction and application of visible-light-driven photocatalysts falls in the central focus for the efficient utilization of renewable solar energy, which provides unprecedented opportunities for addressing the increasing concerns on energy and environmental sustainability. Herein, graphene based Au-TiO2 photocatalysts were fabricated by a simple, one-step microwave-assisted hydrothermal method, using Degussa P25 TiO2 powder (P25), graphene oxide and HAuCl4 aq. soln. as the raw materials. The effects of graphene introduction and gold loading on the photocatalytic hydrogen prodn. rates of the as-prepd. samples in a methanolic aq. soln. were investigated. The results indicated that Au-TiO2-graphene composite had a significantly increased visible light absorption and enhanced photocatalytic H2-prodn. activity compared to the Au-TiO2 composite. In comparison, the pure TiO2, graphene-TiO2 and graphene-Au had no appreciable visible-light-driven H2 prodn. The enhanced photocatalytic H2-prodn. activity of the Au-TiO2-graphene composite is ascribed to (1) the load of the Au nanoparticles which broadens the visible light response of TiO2 due to the surface plasmon resonance (SPR) effect, and (2) the introduction of graphene, which functions as rapid electron transfer units, facilitating the space sepn. of photoelectron and hole pairs. The proposed H2-prodn. activity enhancement mechanism was further confirmed by the transient photocurrent response and electrochem. impedance spectroscopy (EIS) expts.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXislGktbg%253D&md5=b911623920e65817522c05bdb00155b9
277. 277
  Martin, S. T.; Lee, A. T.; Hoffmann, M. R. Chemical Mechanism of Inorganic Oxidants in the Process – Increased Rates of Degradation of Chlorinated Hydrocarbons Environ. Sci. Technol. 1995, 29, 2567– 2573 DOI: 10.1021/es00010a017
  
  There is no corresponding record for this reference.
278. 278
  Vinayan, B. P.; Nagar, R.; Ramaprabhu, S. Solar Light Assisted Green Synthesis of Palladium Nanoparticle Decorated Nitrogen Doped Graphene for Hydrogen Storage Application J. Mater. Chem. A 2013, 1, 11192– 11199 DOI: 10.1039/c3ta12016c
  
  278
  Solar light assisted green synthesis of palladium nanoparticle decorated nitrogen doped graphene for hydrogen storage application
  
  Vinayan, B. P.; Nagar, Rupali; Ramaprabhu, S.
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2013), 1 (37), 11192-11199CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Recent research developments reveal that nanomaterials, esp. C nanomaterials, can play a significant role in the performance enhancement of energy conversion and storage devices. The synthesis procedure of nanomaterials, however, remains one of the governing factors for their wide scale implementation. An in situ synthesis method to prep. Pd nanoparticle decorated N doped graphene sheets (Pd/N-SG) using focused solar radiation is developed. The present synthesis technique combines 3 processes simultaneously, (a) graphene sheet formation, (b) N doping of graphene sheets and (c) metal precursor redn. to metal nanoparticles, in one step through a green approach. The H storage properties of the Pd/N-SG sample are studied using high pressure Sievert's app. and the sample exhibits an excellent H storage capacity of 4.3% at room temp. (25° and 4 MPa H pressure). The method developed for the synthesis is environmentally benign, easy to adopt and economical. Also, the proposed 1-step synthesis method can be easily scaled up to large quantities and this opens a new pathway for the synthesis of nanomaterials for use in the renewable energy field.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtlClsb7E&md5=3649f8f7f1292bb0cd47cbb2bbda4b47
279. 279
  Tuček, J.; Kemp, K. C.; Kim, K. S.; Zbořil, R. Iron-Oxide-Supported Nanocarbon in Lithium-Ion Batteries, Medical, Catalytic, and Environmental Applications ACS Nano 2014, 8, 7571– 7612 DOI: 10.1021/nn501836x
  
  279
  Iron-Oxide-Supported Nanocarbon in Lithium-Ion Batteries, Medical, Catalytic, and Environmental Applications
  
  Tucek, Jiri; Kemp, Kingsley Christian; Kim, Kwang Soo; Zboril, Radek
  
  ACS Nano (2014), 8 (8), 7571-7612CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  A review. Owing to the three different orbital hybridizations carbon can adopt, the existence of various carbon nanoallotropes differing also in dimensionality has been already affirmed with other structures predicted and expected to emerge in the future. Despite numerous unique features and applications of 2D graphene, 1D carbon nanotubes, or 0D fullerenes, nanodiamonds, and carbon quantum dots, which have been already heavily explored, any of the existing carbon allotropes do not offer competitive magnetic properties. For challenging applications, carbon nanoallotropes are functionalized with magnetic species, esp. of iron oxide nature, due to their interesting magnetic properties (superparamagnetism and strong magnetic response under external magnetic fields), easy availability, biocompatibility, and low cost. In addn., combination of iron oxides (magnetite, maghemite, hematite) and carbon nanostructures brings enhanced electrochem. performance and (photo)catalytic capability due to synergetic and cooperative effects. This work aims at reviewing these advanced applications of iron-oxide-supported nanocarbon composites where iron oxides play a diverse role. Various architectures of carbon/iron oxide nanocomposites, their synthetic procedures, physicochem. properties, and applications are discussed in details. A special attention is devoted to hybrids of carbon nanotubes and rare forms (mesoporous carbon, nanofoam) with magnetic iron oxide carriers for advanced environmental technologies. The review also covers the huge application potential of graphene/iron oxide nanocomposites in the field of energy storage, biomedicine, and remediation of environment. Among various discussed medical applications, magnetic composites of zero-dimensional fullerenes and carbon dots are emphasized as promising candidates for complex theranostics and dual magneto-fluorescence imaging.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFSrt7rJ&md5=b89bf42e7f5be8af877cdcc36bc5450c
280. 280
  Kucinskis, G.; Bajars, G.; Kleperis, J. Graphene in Lithium Ion Battery Cathode Materials: A Review J. Power Sources 2013, 240, 66– 79 DOI: 10.1016/j.jpowsour.2013.03.160
  
  280
  Graphene in lithium ion battery cathode materials: A review
  
  Kucinskis, Gints; Bajars, Gunars; Kleperis, Janis
  
  Journal of Power Sources (2013), 240 (), 66-79CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)
  
  A review. Graphene is a relatively new and promising material, displaying a unique array of phys. and chem. properties. Although considered to be esp. promising for the use in energy storage applications, graphene has only recently been implemented as an electron conducting additive for lithium ion battery cathode materials. In current studies graphene is found to significantly improve cathode electrochem. performance. As the charge capacity, rate capability and cyclability of lithium ion batteries are still in ever-remaining need of improvement, this article examines the prospects of graphene implementation into lithium ion battery cathodes to meet such demands. The existing literature and recent advances on the topic have been reviewed, covering the prepn. of graphene and graphene composite lithium ion battery cathodes, their structure and electrochem. properties along with underlying principles for electrochem. performance enhancement of such materials.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtFKntLnO&md5=d1f4c2f6d6c131dbd50a9fb4a5d8e835
281. 281
  Sun, W. W.; Wang, Y. Graphene-Based Nanocomposite Anodes for Lithium-Ion Batteries Nanoscale 2014, 6, 11528– 11552 DOI: 10.1039/C4NR02999B
  
  There is no corresponding record for this reference.
282. 282
  Yang, Q.; Liang, Q.; Liu, J.; Liang, S. Q.; Tang, S. S.; Lu, P. J.; Lu, Y. K. Ultrafine MoO₂ Nanoparticles Grown on Graphene Sheets as Anode Materials for Lithium-Ion Batteries Mater. Lett. 2014, 127, 32– 35 DOI: 10.1016/j.matlet.2014.03.055
  
  282
  Ultrafine MoO2 nanoparticles grown on graphene sheets as anode materials for lithium-ion batteries
  
  Yang, Qian; Liang, Qiang; Liu, Jun; Liang, Shuquan; Tang, Shasha; Lu, Peijie; Lu, Yakun
  
  Materials Letters (2014), 127 (), 32-35CODEN: MLETDJ; ISSN:0167-577X. (Elsevier B.V.)
  
  We have successfully synthesized ultrafine MoO2 nanoparticles with the diam. of ∼5 nm grown on graphene sheets through a facile hydrothermal process which only involves com. MoO3, ethylene glycol and GO as starting materials. More importantly, the ultrafine MoO2 nanoparticle/graphene hybrids exhibit great electrochem. performances with reversible lithium storage capacity as high as 765.3 mA h g-1 after 40 cycles, as anode materials for lithium ion batteries.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXosVajsbg%253D&md5=bc4b489036f1993428c9b54c721ffcf9
283. 283
  Pan, L.; Zhu, X.-D.; Xie, X.-M.; Liu, Y.-T. Smart Hybridization of TiO₂ Nanorods and Fe₃O₄ Nanoparticles with Pristine Graphene Nanosheets: Hierarchically Nanoengineered Ternary Heterostructures for High-Rate Lithium Storage Adv. Funct. Mater. 2015, 25, 3341– 3350 DOI: 10.1002/adfm.201404348
  
  283
  Smart Hybridization of TiO2 Nanorods and Fe3O4 Nanoparticles with Pristine Graphene Nanosheets: Hierarchically Nanoengineered Ternary Heterostructures for High-Rate Lithium Storage
  
  Pan, Long; Zhu, Xiao-Dong; Xie, Xu-Ming; Liu, Yi-Tao
  
  Advanced Functional Materials (2015), 25 (22), 3341-3350CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Today, the ever-increasing demand for large-size power tools has provoked worldwide competition in developing lithium-ion batteries having higher energy and power densities. In this context, advanced anode materials are being extensively pursued, among which TiO2 is particularly promising owing to its high safety, excellent cost and environmental performances, and high cycle stability. However, TiO2 is faced with two detrimental deficiencies, i.e., extremely low theor. capacity and cond. Herein, a smart hybridization strategy is proposed for the hierarchical co-assembly of TiO2 nanorods and Fe3O4 nanoparticles on pristine graphene nanosheets, aiming to simultaneously address the capacity and cond. deficiencies of TiO2 by coupling it with high-capacity (Fe3O4) and high-cond. (pristine graphene) components. The resulting novel, multifunctional ternary heterostructures effectively integrate the intriguing functionalities of the three building blocks: TiO2 as the major active material can adequately retain such merits as high safety and cycle stability, Fe3O4 as the auxiliary active material can contribute extraordinarily high capacities, and pristine graphene as the conductive dopant can guarantee sufficient percolation pathways. Benefiting from a remarkable synergy, the ternary heterostructures deliver superior reversible capacities and rate capabilities, thus casting new light on developing next-generation, high-performance anode materials.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmslensrc%253D&md5=a6721b934319412a72c479a98e1fdbd8
284. 284
  Kasavajjula, U.; Wang, C. S.; Appleby, A. J. Nano- and Bulk-Silicon-Based Insertion Anodes for Lithium-Ion Secondary Cells J. Power Sources 2007, 163, 1003– 1039 DOI: 10.1016/j.jpowsour.2006.09.084
  
  284
  Nano- and bulk-silicon-based insertion anodes for lithium-ion secondary cells
  
  Kasavajjula, Uday; Wang, Chunsheng; Appleby, A. John
  
  Journal of Power Sources (2007), 163 (2), 1003-1039CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.)
  
  A review. The increase in energy d. and power d. requirements for lithium-ion batteries for com. applications has led to a search for higher capacity electrode materials than those available today. Silicon would seem to be a possible alternative for the graphite or carbon anode because its intercalation capacity is the highest known. However, the large capacity fade obsd. during initial cycling has prevented the silicon anode from being commercialized. Methodologies adopted for reducing the capacity fade obsd. in silicon-based anodes are summarized. The challenges that remain in using silicon and silicon-based anodes are discussed and possible approaches for overcoming them are proposed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XhtlCmtLfP&md5=faa41b0a05b78cd9312c5386e4952a39
285. 285
  Zhu, S. M.; Zhu, C. L.; Ma, J.; Meng, Q.; Guo, Z. P.; Yu, Z. Y.; Lu, T.; Li, Y.; Zhang, D.; Lau, W. M. Controlled Fabrication of Si Nanoparticles on Graphene Sheets for Li-Ion Batteries RSC Adv. 2013, 3, 6141– 6146 DOI: 10.1039/c3ra22989k
  
  285
  Controlled fabrication of Si nanoparticles on graphene sheets for Li-ion batteries
  
  Zhu, Shenmin; Zhu, Chengling; Ma, Jun; Meng, Qing; Guo, Zaiping; Yu, Ziyong; Lu, Tao; Li, Yao; Zhang, Di; Lau, Woon Ming
  
  RSC Advances (2013), 3 (17), 6141-6146CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  A new route is presented for the synthesis of Si nanoparticle/Graphene (Si-Gr) composite by a sonochem. method and then magnesiothermic redn. process. During the process, silica particles were firstly synthesized and deposited on the surface of graphene oxide (SiO2-GO) by ultrasonic waves, subsequent low-temp. magnesiothermic redn. transformed SiO2 to Si nanoparticles in situ on graphene sheets. The phase of the obtained materials was influenced by the wt. ratio of Mg to SiO2-GO. With the optimized ratio of 1 : 1, we can get Si nanoparticles on Gr sheets, with the av. particle size of Si around 30 nm. Accordingly, the resultant Si-Gr with 78 wt% Si inside delivered a reversible capacity of 1100 mA h g-1, with very little fading when the charge rates change from 100 mA g-1 to 2000 mA g-1 and then back to 100 mA g-1. Thus, this strategy offers an efficient method for the controlled synthesis of Si nanoparticles on Gr sheets with a high rate performance, attributing to combination of the nanosized Si particles and the graphene.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXltVyju7w%253D&md5=ff3973ef4ba94bcc9493fe7af4195737
286. 286
  Hassan, F. M.; Elsayed, A. R.; Chabot, V.; Batmaz, R.; Xiao, X. C.; Chen, Z. W. Subeutectic Growth of Single-Crystal Silicon Nanowires Grown on and Wrapped with Graphene Nanosheets: High-Performance Anode Material for Lithium-Ion Battery ACS Appl. Mater. Interfaces 2014, 6, 13757– 13764 DOI: 10.1021/am5032067
  
  286
  Subeutectic Growth of Single-Crystal Silicon Nanowires Grown on, and Wrapped with, Graphene Nanosheets: High-Performance Anode Material for Lithium-Ion Battery
  
  Hassan, Fathy M.; Elsayed, Abdel Rahman; Chabot, Victor; Batmaz, Rasim; Xiao, Xingcheng; Chen, Zhongwei
  
  ACS Applied Materials & Interfaces (2014), 6 (16), 13757-13764CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  A novel one-pot synthesis for the subeutectic growth of (111) oriented Si nanowires on an in situ formed nickel nanoparticle catalyst prepd. from an inexpensive nickel nitrate precursor is developed. Addnl., anchoring the nickel nanoparticles to a simultaneously reduced graphene oxide support created synergy between the individual components of the c-SiNW-G composite, which greatly improved the reversible charge capacity and it is retention at high c.d. when applied as an anode for a lithium-ion battery. The c-SiNW-G electrodes for Li-ion battery achieved excellent high-rate performance, producing a stable reversible capacity of 550 mAh g-1 after 100 cycles at 6.8 A g-1 (78% of that at 0.1 A g-1). Thus, with further development this process creates an important building block for a new wave of low-cost silicon nanowire materials and a promising avenue for high rate Li-ion batteries.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1GlurvE&md5=9130d0da641345be874f6b7a6389124b
287. 287
  Zhou, M.; Li, X.; Wang, B.; Zhang, Y.; Ning, J.; Xiao, Z.; Zhang, X.; Chang, Y.; Zhi, L. High-Performance Silicon Battery Anodes Enabled by Engineering Graphene Assemblies Nano Lett. 2015, 15, 6222– 6228 DOI: 10.1021/acs.nanolett.5b02697
  
  287
  High-Performance Silicon Battery Anodes Enabled by Engineering Graphene Assemblies
  
  Zhou, Min; Li, Xianglong; Wang, Bin; Zhang, Yunbo; Ning, Jing; Xiao, Zhichang; Zhang, Xinghao; Chang, Yanhong; Zhi, Linjie
  
  Nano Letters (2015), 15 (9), 6222-6228CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  A novel material/electrode design formula is proposed and an engineered self-supporting electrode configuration, namely, silicon nanoparticle impregnated assemblies of templated carbon-bridged oriented graphene is developed. Their use is demonstrated as binder-free lithium-ion battery anodes with exceptional lithium storage performances, simultaneously attaining high gravimetric capacity (1390 mAh g-1 at 2 A g-1 with respect to the total electrode wt.), high volumetric capacity (1807 mAh cm-3 that is more than three times that of graphite anodes), remarkable rate capability (900 mAh g-1 at 8 A g-1), excellent cyclic stability (0.025% decay per cycle over 200 cycles), and competing areal capacity (as high as 4 and 6 mAh cm-2 at 15 and 3 mA cm-2, resp.). Such combined level of performance is attributed to the templated carbon bridged oriented graphene assemblies involved. This engineered graphene bulk assemblies not only create a robust bicontinuous network for rapid transport of both electrons and lithium ions throughout the electrode even at high material mass loading but also allow achieving a substantially high material tap d. (1.3 g cm-3). Coupled with a simple and flexible fabrication protocol as well as practically scalable raw materials (e.g., silicon nanoparticles and graphene oxide), the material/electrode design developed would propagate new and viable battery material/electrode design principles and opportunities for energy storage systems with high-energy and high-power characteristics.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtlymsLzN&md5=f4d16ca1876519270ab2abe403f513b9
288. 288
  Yuan, F. W.; Tuan, H. Y. Scalable Solution-Grown High-Germanium-Nanoparticle-Loading Graphene Nanocomposites as High-Performance Lithium-Ion Battery Electrodes: An Example of a Graphene-Based Platform toward Practical Full-Cell Applications Chem. Mater. 2014, 26, 2172– 2179 DOI: 10.1021/cm5002016
  
  288
  Scalable solution-grown high-germanium-nanoparticle-loading graphene nanocomposites as high-performance lithium-ion battery electrodes: an example of a graphene-based platform toward practical full-cell applications
  
  Yuan, Fang-Wei; Tuan, Hsing-Yu
  
  Chemistry of Materials (2014), 26 (6), 2172-2179CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)
  
  Graphene in the form of graphene/nanocrystal nanocomposites can improve the electrochem. performance of nanocrystals for lithium-ion (Li-ion) battery anodes, which is esp. important for high-capacity Li-alloy materials such as Si and Ge. For practical full-cell applications, graphene composite electrodes consisting of a large portion of active materials (i.e., a surface of graphene sheets evenly distributed with dense nanoparticles) are required. We have developed a facile soln.-based method to synthesize subgram quantities of nanocomposites composed of reduced graphene oxide (RGO) sheets covered with a high concn. (∼80 wt %) of single-crystal 4.90(±0.80) nm diam. Ge nanoparticles. Subsequently, carbon-coated Ge nanoparticles/RGO (Ge/RGO/C) sandwich structures were formed via a carbonization process. The high-nanoparticle-loading nanocomposites exhibited superior Li-ion battery anode performance when examd. with a series of comprehensive tests, such as receiving a practical capacity of Ge (1332 mAh/g) close (96.2%) to its theor. value (1384 mAh/g) when cycled at a 0.2 C rate and having a high-rate capability over hundreds of cycles. Furthermore, the performance of the full cells assembled using a Ge/RGO/C anode and an LiCoO2 cathode were evaluated. The cells were able to power a wide range of electronic devices, including an light-emitting-diode (LED) array consisting of over 150 bulbs, blue LED arrays, a scrolling LED marquee, and an elec. fan. Thus, this study demonstrates a proof of concept of the use of graphene-based nanocomposites toward practical Li-ion battery applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXisFahu74%253D&md5=1ccd04d62b1441d8e276c0e1cf44253a
289. 289
  Zhang, H. W.; Zhou, L.; Noonan, O.; Martin, D. J.; Whittaker, A. K.; Yu, C. Z. Tailoring the Void Size of Iron Oxide@Carbon Yolk-Shell Structure for Optimized Lithium Storage Adv. Funct. Mater. 2014, 24, 4337– 4342 DOI: 10.1002/adfm.201400178
  
  289
  Tailoring the Void Size of Iron Oxide@Carbon Yolk-Shell Structure for Optimized Lithium Storage
  
  Zhang, Hongwei; Zhou, Liang; Noonan, Owen; Martin, Darren J.; Whittaker, Andrew K.; Yu, Chengzhong
  
  Advanced Functional Materials (2014), 24 (27), 4337-4342CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  High-capacity lithium-ion battery anode materials, such as transition metal oxides, Sn and Si, suffer from large vol. expansion during lithiation, which causes capacity decay. Introducing sufficient void space to accommodate the vol. change is essential to achieve prolonged cycling stability. However, excessive void space may significantly compromise the volumetric energy d. Herein, a method to control the void size in iron oxide@carbon (FeOx@C) yolk-shell structures is developed and the relationship between the void space and electrochem. performance is demonstrated. With an optimized void size, the FeOx@C yolk-shell structure exhibits the best cycling performance. A high reversible capacity of ≈810 mA-h/g is obtained at 0.2C, maintaining 790 mA-h/g after 100 cycles. This contrasts with FeOx@C materials having either smaller or larger void sizes, in which significant capacity fading is obsd. during cycling. This contribution provides an effective approach to alleviate the vol. expansion problem, which can be generally applied to other anode materials to improve their performance in lithium-ion batteries.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXlsFyjsbc%253D&md5=1972345626f474d2b3ebb573a4a81d85
290. 290
  Li, Y.; Zhu, C. L.; Lu, T.; Guo, Z. P.; Zhang, D.; Ma, J.; Zhu, S. M. Simple Fabrication of a Fe₂O₃/Carbon Composite for Use in a High-Performance Lithium Ion Battery Carbon 2013, 52, 565– 573 DOI: 10.1016/j.carbon.2012.10.015
  
  290
  Simple fabrication of a Fe2O3/carbon composite for use in a high-performance lithium ion battery
  
  Li, Yao; Zhu, Chengling; Lu, Tao; Guo, Zaiping; Zhang, Di; Ma, Jun; Zhu, Shenmin
  
  Carbon (2013), 52 (), 565-573CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  A simple approach was developed for the fabrication of a Fe2O3/carbon composite by impregnating activated carbon with a ferric nitrate soln. and calcining it. The composite contains graphitic layers and 10 wt.% Fe2O3 particles of 20-50 nm in diam. The composite has a high sp. surface area of ∼828 m2 g-1 and when used as the anode in a lithium ion battery (LIB), it showed a reversible capacity of 623 mAh g-1 for the first 100 cycles at 50 mA g-1. A discharge capacity higher than 450 mAh g-1 at 1000 mA g-1 was recorded in rate performance testing. This highly improved reversible capacity and rate performance is attributed to the combination of (i) the formation of graphitic layers in the composite, which possibly improves the matrix elec. cond., (ii) the interconnected porous channels whose diams. ranges from the macro- to meso- pore, which increases lithium-ion mobility, and (iii) the Fe2O3 nanoparticles that facilitate the transport of electrons and shorten the distance for Li+ diffusion. This study provides a cost-effective, highly efficient means to fabricate materials which combine conducting carbon with nanoparticles of metal or metal oxide for the development of a high-performance LIB.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1elsbrL&md5=50e8a827c5d6028805d1bdd4ad859533
291. 291
  Slater, M. D.; Kim, D.; Lee, E.; Johnson, C. S. Sodium-Ion Batteries Adv. Funct. Mater. 2013, 23, 947– 958 DOI: 10.1002/adfm.201200691
  
  291
  Sodium-Ion Batteries
  
  Slater, Michael D.; Kim, Donghan; Lee, Eungje; Doeff, Marca; Johnson, Christopher S.
  
  Advanced Functional Materials (2013), 23 (8), 947-958CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A review. The status of ambient temp. sodium ion batteries is reviewed in light of recent developments in anode, electrolyte and cathode materials. These devices, although early in their stage of development, are promising for large-scale grid storage applications due to the abundance and very low cost of sodium-contg. precursors used to make the components. The engineering knowledge developed recently for highly successful Li ion batteries can be leveraged to ensure rapid progress in this area, although different electrode materials and electrolytes will be required for dual intercalation systems based on sodium. In particular, new anode materials need to be identified, since the graphite anode, commonly used in lithium systems, does not intercalate sodium to any appreciable extent. A wider array of choices is available for cathodes, including high performance layered transition metal oxides and polyanionic compds. Recent developments in electrodes are encouraging, but a great deal of research is necessary, particularly in new electrolytes, and the understanding of the SEI films. The engineering modeling calcns. of Na-ion battery energy d. indicate that 210 Wh kg-1 in gravimetric energy is possible for Na-ion batteries compared to existing Li-ion technol. if a cathode capacity of 200 mAh g-1 and a 500 mAh g-1 anode can be discovered with an av. cell potential of 3.3 V.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XntlSnurc%253D&md5=fa5d7d089d261a40896cb6b03e88bfbe
292. 292
  Yu, D. Y. W.; Prikhodchenko, P. V.; Mason, C. W.; Batabyal, S. K.; Gun, J.; Sladkevich, S.; Medvedev, A. G.; Lev, O. High-Capacity Antimony Sulphide Nanoparticle-Decorated Graphene Composite as Anode for Sodium-Ion Batteries Nat. Commun. 2013, 4, 2922 DOI: 10.1038/ncomms3922
  
  292
  High-capacity antimony sulphide nanoparticle-decorated graphene composite as anode for sodium-ion batteries
  
  Yu Denis Y W; Prikhodchenko Petr V; Mason Chad W; Batabyal Sudip K; Gun Jenny; Sladkevich Sergey; Medvedev Alexander G; Lev Ovadia
  
  Nature communications (2013), 4 (), 2922 ISSN:.
  
  Sodium-ion batteries are an alternative to lithium-ion batteries for large-scale applications. However, low capacity and poor rate capability of existing anodes are the main bottlenecks to future developments. Here we report a uniform coating of antimony sulphide (stibnite) on graphene, fabricated by a solution-based synthesis technique, as the anode material for sodium-ion batteries. It gives a high capacity of 730 mAh g(-1) at 50 mA g(-1), an excellent rate capability up to 6C and a good cycle performance. The promising performance is attributed to fast sodium ion diffusion from the small nanoparticles, and good electrical transport from the intimate contact between the active material and graphene, which also provides a template for anchoring the nanoparticles. We also demonstrate a battery with the stibnite-graphene composite that is free from sodium metal, having energy density up to 80 Wh kg(-1). The energy density could exceed that of some lithium-ion batteries with further optimization.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2c3ltFajuw%253D%253D&md5=00d6ac79468675541d9951b7cfb704e0
293. 293
  Xiao, Z. B.; Yang, Z.; Wang, L.; Nie, H. G.; Zhong, M. E.; Lai, Q. Q.; Xu, X. J.; Zhang, L. J.; Huang, S. M. A Lightweight TiO₂/Graphene Interlayer, Applied as a Highly Effective Polysulfide Absorbent for Fast, Long-Life Lithium-Sulfur Batteries Adv. Mater. 2015, 27, 2891– 2898 DOI: 10.1002/adma.201405637
  
  293
  A Lightweight TiO2/Graphene Interlayer, Applied as a Highly Effective Polysulfide Absorbent for Fast, Long-Life Lithium-Sulfur Batteries
  
  Xiao, Zhubing; Yang, Zhi; Wang, Lu; Nie, Huagui; Zhong, Mei-e; Lai, Qianqian; Xu, Xiangju; Zhang, Lijie; Huang, Shaoming
  
  Advanced Materials (Weinheim, Germany) (2015), 27 (18), 2891-2898CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  An integrated selective interlayer was obtained by coating the surface of a C-S battery cathode with a com. graphene-TiO2 film, which accounted for 7.8 wt.% of the entire cathode. The porous graphene afforded an addnl. elec. conductive network and phys. trapped sulfide and polysulfides. The TiO2 in the barrier film further chem. suppressed the dissoln. of polysulfides and alleviated the undesirable shuttle effect. The porous CNT-S cathode coated with the graphene-TiO2 film delivered a reversible specific capacity of 1040 mA-h/g over 300 cycles at 0.5 C, with ultralow capacity degrdn. rates of 0.01% and 0.018% per cycle at 2 and 3 C, resp., over 1000 cycles.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsVKnu7g%253D&md5=1189dc748af9ad475339df2976b10a41
294. 294
  Ryu, W. H.; Yoon, T. H.; Song, S. H.; Jeon, S.; Park, Y. J.; Kim, I. D. Bifunctional Composite Catalysts Using Co₃O₄ Nanofibers Immobilized on Nonoxidized Graphene Nanoflakes for High-Capacity and Long-Cycle Li-O₂ Batteries Nano Lett. 2013, 13, 4190– 4197 DOI: 10.1021/nl401868q
  
  294
  Bifunctional Composite Catalysts Using Co3O4 Nanofibers Immobilized on Non-oxidized Graphene Nanoflakes for High-Capacity and Long-Cycle Li-O2 Batteries
  
  Ryu, Won-Hee; Yoon, Taek-Han; Song, Sung Ho; Jeon, Seokwoo; Park, Yong-Joon; Kim, Il-Doo
  
  Nano Letters (2013), 13 (9), 4190-4197CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Designing a highly efficient catalyst is essential to improve the electrochem. performance of Li-O2 batteries for long-term cycling. Also, these batteries often show significant capacity fading due to the irreversible reaction characteristics of the Li2O2 product. To overcome these limitations, the authors propose a bifunctional composite catalyst composed of electrospun 1-dimensional (1D) Co3O4 nanofibers (NFs) immobilized on both sides of the 2-dimensional nonoxidized graphene nanoflakes (GNFs) for an O electrode in Li-O2 batteries. Highly conductive GNFs with non-covalent functionalization can facilitate a homogeneous dispersion in soln., thereby enabling simple and uniform attachment of 1-dimensional Co3O4 NFs on GNFs without re-stacking. High 1st discharge capacity of 10,500 mA-h/g and superior cyclability for 80 cycles with a limited capacity of 1000 mA-h/g were achieved by (i) improved catalytic activity of 1-dimensional Co3O4 NFs with large surface area, (ii) facile electron transport via interconnected GNFs functionalized by Co3O4 NFs, and (iii) fast O2 diffusion through the ultrathin GNF layer and porous Co3O4 NF networks.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht1arsrvI&md5=2b9cbe928ddead4fddfe284ff568d6e5
295. 295
  Chandra, V.; Park, J.; Chun, Y.; Lee, J. W.; Hwang, I.-C.; Kim, K. S. Water Dispersible Magnetite-Reduced Graphene Oxide Composites for Arsenic Removal ACS Nano 2010, 4, 3979– 3986 DOI: 10.1021/nn1008897
  
  There is no corresponding record for this reference.
296. 296
  Hu, Y.; Jensen, J. O.; Zhang, W.; Huang, Y. J.; Cleemann, L. N.; Xing, W.; Bjerrum, N. J.; Li, Q. F. Direct Synthesis of Fe₃C-Functionalized Graphene by High Temperature Autoclave Pyrolysis for Oxygen Reduction ChemSusChem 2014, 7, 2099– 2103 DOI: 10.1002/cssc.201402183
  
  296
  Direct Synthesis of Fe3C-Functionalized Graphene by High Temperature Autoclave Pyrolysis for Oxygen Reduction
  
  Hu, Yang; Jensen, Jens Oluf; Zhang, Wei; Huang, Yunjie; Cleemann, Lars N.; Xing, Wei; Bjerrum, Niels J.; Li, Qingfeng
  
  ChemSusChem (2014), 7 (8), 2099-2103CODEN: CHEMIZ; ISSN:1864-5631. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A novel approach is presented to direct fabrication of few-layer graphene sheets with encapsulated Fe3C nanoparticles from pyrolysis of volatile non-graphitic precursors without any substrate. This one-step autoclave approach is facile and potentially scalable for prodn. Tested as an electrocatalyst, the graphene-based composite exhibited excellent catalytic activity towards the oxygen redn. reaction in alk. soln. with an onset potential of ca. 1.05 V (vs. the reversible hydrogen electrode) and a half-wave potential of 0.83 V, which is comparable to the com. Pt/C catalyst.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXps1ymur0%253D&md5=10187be0b83250e2bb4d4161b996deb3
297. 297
  Moussa, S. O.; Panchakarla, L. S.; Ho, M. Q.; El-Shall, M. S. Graphene-Supported, Iron-Based Nanoparticles for Catalytic Production of Liquid Hydrocarbons from Synthesis Gas: The Role of the Graphene Support in Comparison with Carbon Nanotubes ACS Catal. 2014, 4, 535– 545 DOI: 10.1021/cs4010198
  
  297
  Graphene-Supported, Iron-Based Nanoparticles for Catalytic Production of Liquid Hydrocarbons from Synthesis Gas: The Role of the Graphene Support in Comparison with Carbon Nanotubes
  
  Moussa, Sherif O.; Panchakarla, Leela S.; Ho, Minh Q.; El-Shall, M. Samy
  
  ACS Catalysis (2014), 4 (2), 535-545CODEN: ACCACS; ISSN:2155-5435. (American Chemical Society)
  
  Fischer-Tropsch synthesis (FTS) is a potentially attractive technol. for the prodn. of clean liq. fuels from synthesis gas. The efficiency and selectivity of FTS can be enhanced by the design of new active catalyst systems with improved selectivity for long-chain hydrocarbons and low methane prodn. In this paper, we introduce a new class of FT catalysts supported on the high surface area graphene nanosheets and report on their high activity and selectivity for the prodn. of long-chain hydrocarbons. The chem. redn. of graphene oxide in water in the presence of the metal salts under microwave irradn. allows the deposition of well-dispersed surface-oxidized metal nanoparticles on the defect sites of the graphene nanosheets. The Fe-K-nanoparticle catalyst supported on graphene exhibits high activity and selectivity toward C8 and higher hydrocarbons with excellent stability and recyclability. In comparison with other carbon supports, such as carbon nanotubes, the graphene support shows a unique tendency for minor formation of the low-value and undesirable products methane and carbon dioxide, resp. The water-gas shift activity is reduced on the graphene support as compared with CNTs, and as a result, the formation of CO2 is significantly reduced. Evidence is presented for the formation of the active Fe5C2 iron carbide phase during the FTS on the graphene-supported Fe catalysts. The high activity and selectivity of the catalysts supported on graphene are correlated with the presence of defects within the graphene lattice that act as favorable nucleation sites to anchor the metal nanoparticles, thus providing tunable metal-support interactions. Given the activity, selectivity, and stability of the new graphene-supported, Fe-based nanoparticle catalysts, their industrial application appears to be promising. Controlling the nature and d. of the defect sites in graphene could lead to improved understanding of the catalyst-graphene interactions and to further enhancement of the performance of these catalysts for the prodn. of liq. fuels.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvFymsLjP&md5=40c9922c18773e14ff917fa336f4b10f
298. 298
  Xu, X.; Li, H.; Zhang, Q.; Hu, H.; Zhao, Z.; Li, J.; Li, J.; Qiao, Y.; Gogotsi, Y. Self-Sensing, Ultra light, and Conductive 3D Graphene/Iron Oxide Aerogel Elastomer Deformable in a Magnetic Field ACS Nano 2015, 9, 3969– 3977 DOI: 10.1021/nn507426u
  
  There is no corresponding record for this reference.
299. 299
  Chen, Y.; Wang, Y. L.; Zhang, H. B.; Li, X. F.; Gui, C. X.; Yu, Z. Z. Enhanced Electromagnetic Interference Shielding Efficiency of Polystyrene/Graphene Composites with Magnetic Fe₃O₄ Nanoparticles Carbon 2015, 82, 67– 76 DOI: 10.1016/j.carbon.2014.10.031
  
  299
  Enhanced electromagnetic interference shielding efficiency of polystyrene/graphene composites with magnetic Fe3O4 nanoparticles
  
  Chen, Yu; Wang, Yongli; Zhang, Hao-Bin; Li, Xiaofeng; Gui, Chen-Xi; Yu, Zhong-Zhen
  
  Carbon (2015), 82 (), 67-76CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  Polystyrene (PS) composites with satisfactory electromagnetic interference (EMI) shielding performance were prepd. by soln. blending of PS with thermally exfoliated and reduced graphene oxide (TGO) and modified Fe3O4 nanoparticles. For comparison, Fe3O4@reduced graphene oxide (RGO) hybrid and its PS composites were also prepd. The morphologies of Fe3O4@RGO hybrid and Fe3O4 nanoparticles were studied in terms of microstructure and magnetic properties. Surface modification of Fe3O4 nanoparticles enhances their compatibility with PS and thus their uniform dispersion in the PS matrix. Much higher elec. cond. and EMI shielding effectiveness are achieved for PS/TGO/Fe3O4 composites in comparison to those of PS/Fe3O4@RGO composites. Interestingly, PS/TGO/Fe3O4 composites exhibit obviously improved EMI shielding effectiveness in relative to that of PS/TGO composite although their elec. conductivities are similar. The EMI shielding effectiveness of PS/TGO/Fe3O4 composite is more than 30 dB in the frequency range of 9.8-12 GHz with only 2.24% of graphene. The effect of Fe3O4 size on the composite properties is investigated and the EMI shielding mechanism is discussed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsl2lt7nN&md5=c06486c88867f3c402ba781c664cf867
300. 300
  Yao, K.; Gong, J.; Tian, N. N.; Lin, Y. C.; Wen, X.; Jiang, Z. W.; Na, H.; Tang, T. Flammability Properties and Electromagnetic Interference Shielding of PVC/Graphene Composites Containing Fe₃O₄ nanoparticles RSC Adv. 2015, 5, 31910– 31919 DOI: 10.1039/C5RA01046B
  
  300
  Flammability properties and electromagnetic interference shielding of PVC/graphene composites containing Fe3O4 nanoparticles
  
  Yao, Kun; Gong, Jiang; Tian, Nana; Lin, Yichao; Wen, Xin; Jiang, Zhiwei; Na, Hui; Tang, Tao
  
  RSC Advances (2015), 5 (40), 31910-31919CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  The effects of combined graphene/Fe3O4 nanoparticles on the flame retardancy and smoke suppression of PVC were studied. The dispersion state of graphene in the PVC matrix was improved with the help of Fe3O4 nanoparticles. As a result, the peak values of heat release rate and smoke prodn. rate measured by cone calorimetry were obviously decreased in the PVC/graphene/Fe3O4 composites. According to the results from TGA tests and structural characterization of residual char, the improved flame retardancy was partially attributed to the formation of a network-like structure due to the good dispersion state of graphene in the PVC matrix, and partially to the carbonization of degrdn. products of PVC catalyzed by Fe3O4 nanoparticles. In addn., ternary PVC composites showed higher mech. properties than pure PVC. More importantly, the resulting material possessed both elec. and magnetic properties. As a result, the ternary composites showed favorable electromagnetic shielding efficiency in the X-band frequency region (8-12 GHz), due to the formation of conducting interconnected graphene-based networks in the insulating PVC matrix and the magnetic properties.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlsVOqtLo%253D&md5=bab4a4f7bcbcdbc4e01b8cb75090f6ad
301. 301
  Singh, A. P.; Mishra, M.; Hashim, D. P.; Narayanan, T. N.; Hahm, M. G.; Kumar, P.; Dwfuedi, J.; Kedawat, G.; Gupta, A.; Singh, B. P. Probing the Engineered Sandwich Network of Vertically Aligned Carbon Nanotube-Reduced Graphene Oxide Composites for High Performance Electromagnetic Interference Shielding Applications Carbon 2015, 85, 79– 88 DOI: 10.1016/j.carbon.2014.12.065
  
  301
  Probing the engineered sandwich network of vertically aligned carbon nanotube-reduced graphene oxide composites for high performance electromagnetic interference shielding applications
  
  Singh, Avanish Pratap; Mishra, Monika; Hashim, Daniel P.; Narayanan, T. N.; Hahm, Myung Gwan; Kumar, Pawan; Dwivedi, Jaya; Kedawat, Garima; Gupta, Ankit; Singh, Bhanu Pratap; Chandra, Amita; Vajtai, Robert; Dhawan, S. K.; Ajayan, Pulickel M.; Gupta, Bipin Kumar
  
  Carbon (2015), 85 (), 79-88CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  Herein, the authors developed a strategy for fabrication of iron oxide infiltrated vertically aligned multiwalled carbon nanotubes (MWCNT forest) sandwiched with reduced graphene oxide (rGO) sheets network for high performance electromagnetic interference (EMI) shielding application which offers a new avenue in this area. Such engineered sandwiched network exhibits enhanced shielding effectiveness compared to conventional EMI shielding materials. This network of exotic carbons demonstrates the shielding effectiveness value >37 dB (>99.98% attenuation) in Ku-band (12.4-18 GHz), which is greater than the recommended limit (∼30 dB) for techno-com. applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitVagtw%253D%253D&md5=d60bf22e3c7e886c75a9de8258e21e64
302. 302
  Kumar, S.; Singh, A. K.; Dasmahapatra, A. K.; Mandal, T. K.; Bandyopadhyay, D. Graphene Based Multifunctional Superbots Carbon 2015, 89, 31– 40 DOI: 10.1016/j.carbon.2015.03.012
  
  302
  Graphene based multifunctional superbots
  
  Kumar, Sunny; Singh, Amit Kumar; Dasmahapatra, Ashok Kumar; Mandal, Tapas Kumar; Bandyopadhyay, Dipankar
  
  Carbon (2015), 89 (), 31-40CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  A versatile graphene coated glass microswimmer displayed directed motions under the influence of applied elec. field, chem. potential gradient and external magnetic field. The directed chem. locomotion took place from the region of lower to higher pH with speed ∼13 body lengths per s due to asym. catalytic decompn. of dil. hydrogen peroxide across the motor surface. The neg. surface potential of graphene coated motor developed an elec. double layer in an alk. medium which in turn engendered electrophoretic mobility towards anode when the external electrostatic field was applied. Inclusion of sparsely populated ferromagnetic iron nanoparticles on the surface of the motor offered the magnetic remote control on the motion. The coupled in situ and external controls enabled the motor to develop complex motions in diverse open and confined environments. For example, the motor could approach, pick-up, tow, and release a heavy cargo inside microchannel. Remarkably, the motor (∼67 μg) could successfully drive out a ∼1000 times heavier payload (∼0.67 mg) displaying the ability to overcome the drag force of ∼2619 pN with the help of coupled in situ and remote guidance.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXktlOrurw%253D&md5=3f1c308257a43de382fb8ad544036906
303. 303
  Jiang, Z.; Li, J.; Aslan, H.; Li, Q.; Li, Y.; Chen, M.; Huang, Y.; Froning, J. P.; Otyepka, M.; Zboril, R. A High Efficiency H₂S Gas Sensor Material: Paper Like Fe₂O₃/graphene Nanosheets and Structural Alignment Dependency of Device Efficiency J. Mater. Chem. A 2014, 2, 6714– 6717 DOI: 10.1039/c3ta15180h
  
  303
  A high efficiency H2S gas sensor material: paper like Fe2O3/graphene nanosheets and structural alignment dependency of device efficiency
  
  Jiang, Zaixing; Li, Jun; Aslan, Huesnue; Li, Qiang; Li, Yue; Chen, Menglin; Huang, Yudong; Froning, Jens Peter; Otyepka, Michal; Zboril, Radek; Besenbacher, Flemming; Dong, Mingdong
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (19), 6714-6717CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Fe2O3/graphene was synthesized successfully by a super crit. CO2-assisted thermal method and further made into paper-like nanosheets by directed-flow, vertical assembly of individual Fe2O3/graphene nanosheets under a controlled magnetic field. Characterization of the samples was carried out by both electron microscopy and XPS. The sensor materials outperform many other paper-like materials for H2S gas detection. In addn., vertically and horizontally aligned nanosheets were used as sensing materials to detect H2S gas along with chemiluminescence measurements. Importantly, the nanoscale Fe2O3/graphene sheets with the vertical arrangement are more beneficial than the nanosheets with the horizontal arrangement in terms of sensitivity.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXmtlGgtbc%253D&md5=f87a6600d13e606dc5e1b77c9c2df303
304. 304
  Wang, K.; Wan, S.; Liu, Q.; Yang, N.; Zhai, J. CdS Quantum Dot-Decorated Titania/Graphene Nanosheets Stacking Structures for Enhanced Photoelectrochemical Solar Cells RSC Adv. 2013, 3, 23755– 23761 DOI: 10.1039/c3ra43770a
  
  304
  CdS quantum dot-decorated titania/graphene nanosheets stacking structures for enhanced photoelectrochemical solar cells
  
  Wang, Kefeng; Wan, Sijie; Liu, Qingqing; Yang, Nailiang; Zhai, Jin
  
  RSC Advances (2013), 3 (45), 23755-23761CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  Quantum dot (QD)-decorated stacking structures of graphene (G) and titania nanosheets (TNS) have been fabricated through a layer-by-layer technique assocd. with a successive ionic layer adsorption and reaction method. The photoanodes with such stacking structures exhibit enhanced photocurrent responses under simulated solar light irradn. Compared with the photoanodes without graphene, the photoanodes integrated with graphene could greatly enhance the photocurrent generation. Though the thickness of the multilayer films in our expt. is on the nanometer scale, a considerable photoelec. conversion efficiency has been obtained by employing such a stacking structure for the photoelectrochem. solar cell. The stacking structure synchronously taking advantage of the conductive property of graphene and the visible light-harvesting ability of quantum dots will enlighten the fabrication of novel energy conversion devices.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs1yltrfE&md5=f6de3127f542bd2418509a7e6c8a382b
305. 305
  Bi, E.; Su, Y.; Chen, H.; Yang, X.; Yin, M.; Ye, F.; Li, Z.; Han, L. A Hybrid Catalyst Composed of Reduced Graphene Oxide/Cu₂S Quantum Dots as a Transparent Counter Electrode for Dye Sensitized Solar Cells RSC Adv. 2015, 5, 9075– 9078 DOI: 10.1039/C4RA14029J
  
  305
  A hybrid catalyst composed of reduced graphene oxide/Cu2S quantum dots as a transparent counter electrode for dye sensitized solar cells
  
  Bi, Enbing; Su, Yanjie; Chen, Han; Yang, Xudong; Yin, Maoshu; Ye, Fei; Li, Zhongli; Han, Liyuan
  
  RSC Advances (2015), 5 (12), 9075-9078CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  We synthesized a hybrid catalyst of reduced graphene oxide/Cu2S quantum dots (RGO/Cu2S QDs) via a facile wet chem. approach. The synergistic effect between ultrathin-RGO and ultrasmall-QDs endowed the hybrid catalyst with a high transparent performance, excellent cond. and catalytic activity. A dye-sensitized solar cell fabricated with the hybrid catalyst showed the overall power conversion efficiency was 7.12%, which was comparable to that of a Pt-based device.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFOgtbzP&md5=47b02367136bfc4c382894b203aee0b8
306. 306
  Fu, M.; Jiao, Q.; Zhao, Y. One-Step Vapor Diffusion Synthesis of Uniform CdS Quantum Dots/Reduced Graphene Oxide Composites as Efficient Visible-Light Photocatalysts RSC Adv. 2014, 4, 23242– 23250 DOI: 10.1039/c4ra02000f
  
  306
  One-step vapor diffusion synthesis of uniform CdS quantum dots/reduced graphene oxide composites as efficient visible-light photocatalysts
  
  Fu, Min; Jiao, Qingze; Zhao, Yun
  
  RSC Advances (2014), 4 (44), 23242-23250CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  CdS quantum dots (QDs)/reduced graphene oxide (RGO) composites were synthesized through a one-step vapor diffusion process in the presence of ethylene glycol. The in situ growth of CdS QDs and the redn. of graphene oxide (GO) were completed simultaneously. Fourier transform IR spectra, X-ray diffraction patterns, XPS and Raman spectroscopy confirmed the redn. of GO. Electron microscopy indicated uniform CdS QDs with size around 4-7 nm were well distributed on the RGO sheets. The transient photocurrent response, electrochem. impedance spectroscopy and diffuse reflectance UV-visible spectra of CdS QDs/RGO composites and CdS were tested to explain the role of RGO for the photocatalytic reaction. As-obtained composites exhibited better photocatalytic properties than pure CdS under visible light irradn. The influence of different contents of GO on photocatalytic performance was also investigated. A possible photocatalytic mechanism of CdS QDs/RGO composites was proposed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXpsVSisbo%253D&md5=94fc43061a648e2281dcf56b52dd8617
307. 307
  Mo, R.; Lei, Z.; Sun, K.; Rooney, D. Facile Synthesis of Anatase TiO₂ Quantum- Dot/Graphene Nanosheet Composites with Enhanced Electrochemical Performance for Lithium-Ion Batteries Adv. Mater. 2014, 26, 2084– 2088 DOI: 10.1002/adma.201304338
  
  There is no corresponding record for this reference.
308. 308
  Zeng, X.; Tu, W.; Li, J.; Bao, J.; Dai, Z. Photoelectrochemical Biosensor Using Enzyme-Catalyzed in Situ Propagation of CdS Quantum Dots on Graphene Oxide ACS Appl. Mater. Interfaces 2014, 6, 16197– 16203 DOI: 10.1021/am5043164
  
  308
  Photoelectrochemical Biosensor Using Enzyme-Catalyzed in Situ Propagation of CdS Quantum Dots on Graphene Oxide
  
  Zeng, Xianxiang; Tu, Wenwen; Li, Jing; Bao, Jianchun; Dai, Zhihui
  
  ACS Applied Materials & Interfaces (2014), 6 (18), 16197-16203CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  An innovative photoelectrochem. (PEC) biosensor platform was designed based on the in situ generation of CdS quantum dots (QDs) on graphene oxide (GO) using an enzymic reaction. Horseradish peroxidase catalyzed the redn. of sodium thiosulfate with hydrogen peroxide to generate H2S, which reacted with Cd2+ to form CdS QDs. CdS QDs could be photoexcited to generate an elevated photocurrent as a readout signal. This strategy offered a "green" alternative to inconvenient presynthesis procedures for the fabrication of semiconducting nanoparticles. The nanomaterials and assembly procedures were characterized by microscopy and spectroscopy techniques. Combined with immune recognition and on the basis of the PEC activity of CdS QDs on GO, the strategy was successfully applied to a PEC assay to detect carcinoembryonic antigen and displayed a wide linear range from 2.5 ng mL-1 to 50 μg mL-1 and a detection limit of 0.72 ng mL-1 at a signal-to-noise ratio of 3. The PEC biosensor showed satisfactory performance for clin. sample detection and was convenient for detg. high concns. of solute without diln. This effort offers a new opportunity for the development of numerous rapid and convenient anal. techniques using the PEC method that may be applied in the design and prepn. of various solar-energy-driven applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVSrtb%252FE&md5=61df8a3c6fae059e342ce29b5b106dbd
309. 309
  Jiang, S.-D.; Tang, G.; Ma, Y.-F.; Hu, Y.; Song, L. Synthesis of Nitrogen-Doped Graphene-ZnS Quantum Dots Composites with Highly Efficient Visible Light Photodegradation Mater. Chem. Phys. 2015, 151, 34– 42 DOI: 10.1016/j.matchemphys.2014.11.019
  
  309
  Synthesis of nitrogen-doped graphene-ZnS quantum dots composites with highly efficient visible light photodegradation
  
  Jiang, Shu-Dong; Tang, Gang; Ma, Yi-Fei; Hu, Yuan; Song, Lei
  
  Materials Chemistry and Physics (2015), 151 (), 34-42CODEN: MCHPDR; ISSN:0254-0584. (Elsevier B.V.)
  
  Nitrogen-doped graphene-ZnS quantum dots (NG-ZnS QDs) were synthesized by a one-pot hydrothermal process using graphene oxide and [(Zn2S2) (pa)] nanosheets as precursors. The results demonstrated that ZnS QDs deposited on the surface of the nitrogen-doped graphene (NG). Combined with series of our anal. and characterization, we found that [(Zn2S2) (pa)] nanosheets were used not only as the sources of ZnS QDs but also as the sources of nitrogen. Moreover, photocatalytic expt. of NG-ZnS QDs for org. dyes was conducted under visible light irradn., and the results exhibited that the photocatalytic activities of resultant composites could be remarkably enhanced. This simple and catalyst-free approach for depositing ZnS QDs onto NG may provide an alternative way for prepn. of other composites based on NG under mild conditions, which showed their potential applications in wastewater treatment.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvV2nu77M&md5=a9483fae9131241f3eb8217c6f42223c
310. 310
  Xia, H.; Hong, C.; Li, B.; Zhao, B.; Lin, Z.; Zheng, M.; Savilov, S. V.; Aldoshin, S. M. Facile Synthesis of Hematite Quantum-Dot/Functionalized Graphene-Sheet Composites as Advanced Anode Materials for Asymmetric Supercapacitors Adv. Funct. Mater. 2015, 25, 627– 635 DOI: 10.1002/adfm.201403554
  
  310
  Facile Synthesis of Hematite Quantum-Dot/Functionalized Graphene-Sheet Composites as Advanced Anode Materials for Asymmetric Supercapacitors
  
  Xia, Hui; Hong, Caiyun; Li, Bo; Zhao, Bin; Lin, Zixia; Zheng, Mingbo; Savilov, Serguei V.; Aldoshin, Serguei M.
  
  Advanced Functional Materials (2015), 25 (4), 627-635CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  For building high-energy d. asym. supercapacitors, developing anode materials with large specific capacitance remains a great challenge. Although Fe2O3 has been considered as a promising anode material for asym. supercapacitors, the specific capacitance of the Fe2O3-based anodes is still low and cannot match that of cathodes in the full cells. In this work, a composite material with well dispersed Fe2O3 quantum dots (QDs, ≈2 nm) decorated on functionalized graphene sheets (FGS) is prepd. by a facile and scalable method. The Fe2O3 QDs/FGS composites exhibit a large specific capacitance up to 347 F/g in 1M Na2SO4 between -1 and 0 V vs. Ag/AgCl. An asym. supercapacitor operating at 2 V is fabricated using Fe2O3/FGS as anode and MnO2/FGS as cathode in 1M Na2SO4 aq. electrolyte. The Fe2O3/FGS//MnO2/FGS asym. supercapacitor has a high energy d. of 50.7 W-h/kg at a power d. of 100 W/kg as well as excellent cycling stability and power capability. The facile synthesis method and superior supercapacitive performance of the Fe2O3 QDs/FGS composites make them promising as anode materials for high-performance asym. supercapacitors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVyhtbrL&md5=b144310053facad6d09a069a62846b31
311. 311
  Chao, D.; Zhu, C.; Xia, X.; Liu, J.; Zhang, X.; Wang, J.; Liang, P.; Lin, J.; Zhang, H.; Shen, Z. X. Graphene Quantum Dots Coated VO₂ Arrays for Highly Durable Electrodes for Li and Na Ion Batteries Nano Lett. 2015, 15, 565– 573 DOI: 10.1021/nl504038s
  
  311
  Graphene Quantum Dots Coated VO2 Arrays for Highly Durable Electrodes for Li and Na Ion Batteries
  
  Chao, Dongliang; Zhu, Changrong; Xia, Xinhui; Liu, Jilei; Zhang, Xiao; Wang, Jin; Liang, Pei; Lin, Jianyi; Zhang, Hua; Shen, Ze Xiang; Fan, Hong Jin
  
  Nano Letters (2015), 15 (1), 565-573CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Nanoscale surface engineering is playing important role in enhancing the performance of battery electrode. VO2 is one of high-capacity but less-stable materials and has been used mostly in the form of powders for Li-ion battery cathode with mediocre performance. In this work, we design a new type of binder-free cathode by bottom-up growth of bifacial VO2 arrays directly on a graphene network for both high-performance Li-ion and Na-ion battery cathodes. More importantly, graphene quantum dots are coated onto the VO2 surfaces as a highly efficient surface sensitizer and protection to further boost the electrochem. properties. The integrated electrodes deliver a Na storage capacity of 306 mA-h/g at 100 mA/g, and a capacity of more than 110 mA-h/g after 1500 cycles at 18 A/g. Our result on Na-ion battery may pave the way to next generation post-lithium batteries.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFehsL7L&md5=64c5ad4c1680e984a714a38620297d09
312. 312
  Yeh, T. F.; Teng, C. Y.; Chen, S. J.; Teng, H. Nitrogen-Doped Graphene Oxide Quantum Dots as Photocatalysts for Overall Water-Splitting under Visible Light Illumination Adv. Mater. 2014, 26, 3297– 3303 DOI: 10.1002/adma.201305299
  
  312
  Nitrogen-Doped Graphene Oxide Quantum Dots as Photocatalysts for Overall Water-Splitting under Visible Light Illumination
  
  Yeh, Te-Fu; Teng, Chiao-Yi; Chen, Shean-Jen; Teng, Hsisheng
  
  Advanced Materials (Weinheim, Germany) (2014), 26 (20), 3297-3303CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Based on the structural characteristics required for photocatalytic water-splitting, we synthesized nitrogen-doped graphene oxide-quantum dots (NGO-QDs) as the catalyst. The NGO-QDs exhibited both p- and n-type conductivities, based on the results of the electrochem. Mott-Schottky anal. The prominent photo-luminescence emission indicated that photochem. p-n diodes constituted the NGO-QDs. The diode configuration resulted in an internal Z-scheme charge transfer for effective reaction at the QD interface. Visible light (>420 nm) irradn. on the NGO-QDs resulted in simultaneous H2 and O2 evolution from pure water at an H2:O2 molar ratio of 2:1. This paper demonstrated that graphene species are promising materials for synthesizing metal-free, cost-effective, and environmentally-friendly catalysts for overall water-splitting under solar illumination.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjtVKitLo%253D&md5=f4fd608871457493615d9bc17a724210
313. 313
  Chao, D.; Zhu, C.; Xia, X.; Liu, J.; Zhang, X.; Wang, J.; Liang, P.; Lin, J.; Zhang, H.; Shen, Z. X. Graphene Quantum Dots Coated VO₂ Arrays for Highly Durable Electrodes for Li and Na Ion Batteries Nano Lett. 2015, 15, 565– 573 DOI: 10.1021/nl504038s
  
  313
  Graphene Quantum Dots Coated VO2 Arrays for Highly Durable Electrodes for Li and Na Ion Batteries
  
  Chao, Dongliang; Zhu, Changrong; Xia, Xinhui; Liu, Jilei; Zhang, Xiao; Wang, Jin; Liang, Pei; Lin, Jianyi; Zhang, Hua; Shen, Ze Xiang; Fan, Hong Jin
  
  Nano Letters (2015), 15 (1), 565-573CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Nanoscale surface engineering is playing important role in enhancing the performance of battery electrode. VO2 is one of high-capacity but less-stable materials and has been used mostly in the form of powders for Li-ion battery cathode with mediocre performance. In this work, we design a new type of binder-free cathode by bottom-up growth of bifacial VO2 arrays directly on a graphene network for both high-performance Li-ion and Na-ion battery cathodes. More importantly, graphene quantum dots are coated onto the VO2 surfaces as a highly efficient surface sensitizer and protection to further boost the electrochem. properties. The integrated electrodes deliver a Na storage capacity of 306 mA-h/g at 100 mA/g, and a capacity of more than 110 mA-h/g after 1500 cycles at 18 A/g. Our result on Na-ion battery may pave the way to next generation post-lithium batteries.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFehsL7L&md5=64c5ad4c1680e984a714a38620297d09
314. 314
  He, P.; Sun, J.; Tian, S.; Yang, S.; Ding, S.; Ding, G.; Xie, X.; Jiang, M. Processable Aqueous Dispersions of Graphene Stabilized by Graphene Quantum Dots Chem. Mater. 2015, 27, 218– 226 DOI: 10.1021/cm503782p
  
  314
  Processable Aqueous Dispersions of Graphene Stabilized by Graphene Quantum Dots
  
  He, Peng; Sun, Jing; Tian, Suyun; Yang, Siwei; Ding, Shengju; Ding, Guqiao; Xie, Xiaoming; Jiang, Mianheng
  
  Chemistry of Materials (2015), 27 (1), 218-226CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)
  
  Dispersing graphene in various solvents is one of the key technologies toward the practical applications of graphene. Herein, using graphene quantum dots (GQDs) as stabilizer, aq. dispersions of graphene with good stability were demonstrated by directly dispersing commercialized graphene powder into water. Amazingly, 100 mg of graphene powder could be stabilized by an av. of merely 7.8 mg GQDs to form aq. dispersions with a max. concn. of up to 0.4 mg/mL and stability at least 3 mo. The introduction of a small amt. of GQDs also allowed for the fabrication of water-redispersible graphene slurry and powder, which would largely facilitate the transportation and applications of graphene. The mechanism of the GQDs stabilized graphene in water was proposed and exptl. verified through UV-visible spectroscopy and zeta potential measurements. Moreover, flexible graphene papers directly assembled from the water-dispersible graphene exhibited controllable thickness, good cond., and acceptable strength. With properties not compromised by GQDs, water-dispersible graphene is expected to be widely applicable in elec. and electrochem. device fields.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVams7rF&md5=2551ba47c097dd467ef3202d5500dafe
315. 315
  Lin, Y.; Chapman, R.; Stevens, M. M. Integrative Self-Assembly of Graphene Quantum Dots and Biopolymers into a Versatile Biosensing Toolkit Adv. Funct. Mater. 2015, 25, 3183– 3192 DOI: 10.1002/adfm.201500624
  
  315
  Integrative Self-Assembly of Graphene Quantum Dots and Biopolymers into a Versatile Biosensing Toolkit
  
  Lin, Yiyang; Chapman, Robert; Stevens, Molly M.
  
  Advanced Functional Materials (2015), 25 (21), 3183-3192CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Hybrid self-assembly has become a reliable approach to synthesize soft materials with multiple levels of structural complexity and synergistic functionality. Photoluminescent graphene quantum dots (GQDs, 2-5 nm) were used for the first time as mol.-like building blocks to construct self-assembled hybrid materials for label-free biosensors. Ionic self-assembly of disk-shaped GQDs and charged biopolymers generates a series of hierarchical structures that exhibit aggregation-induced fluorescence quenching of the GQDs and change the protein/polypeptide secondary structure. The integration of GQDs and biopolymers via self-assembly offers a flexible toolkit for the design of label-free biosensors in which the GQDs serve as a fluorescent probe and the biopolymers provide biol. function. The versatility of this approach is demonstrated in the detection of glycosaminoglycans (GAGs), pH, and proteases using three strategies: (1) competitive binding of GAGs to biopolymers, (2) pH-responsive structural changes of polypeptides, and (3) enzymic hydrolysis of the protein backbone, resp. It is anticipated that the integrative self-assembly of biomols. and GQDs will open up new avenues for the design of multifunctional biomaterials with combined optoelectronic properties and biol. applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmsFyqs78%253D&md5=2bc64240a580ba1d416fe26e1a845811
316. 316
  Zhang, Q.; Jie, J.; Diao, S.; Shao, Z.; Zhang, Q.; Wang, L.; Deng, W.; Hu, W.; Xia, H.; Yuan, X. Solution-Processed Graphene Quantum Dot Deep-UV Photodetectors ACS Nano 2015, 9, 1561– 1570 DOI: 10.1021/acsnano.5b00437
  
  316
  Solution-Processed Graphene Quantum Dot Deep-UV Photodetectors
  
  Zhang, Qing; Jie, Jiansheng; Diao, Senlin; Shao, Zhibin; Zhang, Qiao; Wang, Liu; Deng, Wei; Hu, Weida; Xia, Hui; Yuan, Xiaodong; Lee, Shuit-Tong
  
  ACS Nano (2015), 9 (2), 1561-1570CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Fast-response and high-sensitivity deep-UV (DUV) photodetectors with detection wavelength shorter than 320 nm are in high demand due to their potential applications in diverse fields. However, the fabrication processes of DUV detectors based on traditional semiconductor thin films are complicated and costly. Here we report a high-performance DUV photodetector based on graphene quantum dots (GQDs) fabricated via a facile soln. process. The devices are capable of detecting DUV light with wavelength as short as 254 nm. With the aid of an asym. electrode structure, the device performance could be significantly improved. An on/off ratio of ∼6000 under 254 nm illumination at a relatively weak light intensity of 42 μW cm-2 is achieved. The devices also exhibit excellent stability and reproducibility with a fast response speed. Given the soln.-processing capability of the devices and extraordinary properties of GQDs, the use of GQDs will open up unique opportunities for future high-performance, low-cost DUV photodetectors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhsF2itbo%253D&md5=71979acc7c275e07a0f809a8560ec60e
317. 317
  Song, S. H.; Jang, M. H.; Chung, J.; Jin, S. H.; Kim, B. H.; Hur, S. H.; Yoo, S. H.; Cho, Y. H.; Jeon, S. W. Highly Efficient Light-Emitting Diode of Graphene Quantum Dots Fabricated from Graphite Intercalation Compounds Adv. Opt. Mater. 2014, 2, 1016– 1023 DOI: 10.1002/adom.201400184
  
  317
  Highly Efficient Light-Emitting Diode of Graphene Quantum Dots Fabricated from Graphite Intercalation Compounds
  
  Song, Sung Ho; Jang, Min-Ho; Chung, Jin; Jin, Sung Hawn; Kim, Bo Hyun; Hur, Seung-Hyun; Yoo, Seunghyup; Cho, Yong-Hoon; Jeon, Seokwoo
  
  Advanced Optical Materials (2014), 2 (11), 1016-1023CODEN: AOMDAX; ISSN:2195-1071. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  This article describes highly efficient light-emitting diode of graphene quantum dots fabricated from graphite intercalation compds.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvFagt7jO&md5=fcb4ae3463eafdbdea180d011f0d5e44
318. 318
  Kumar, P. N.; Mandal, S.; Deepa, M.; Srivastava, A. K.; Joshi, A. G. Functionalized Graphite Platelets and Lead Sulfide Quantum Dots Enhance Solar Conversion Capability of a Titanium Dioxide/Cadmium Sulfide Assembly J. Phys. Chem. C 2014, 118, 18924– 18937 DOI: 10.1021/jp5052408
  
  There is no corresponding record for this reference.
319. 319
  Jung, M. H.; Chu, M. J. Comparative Experiments of Graphene Covalently and Physically Binding CdSe Quantum Dots to Enhance the Electron Transport in Flexible Photovoltaic Devices Nanoscale 2014, 6, 9241– 9249 DOI: 10.1039/C4NR02254H
  
  319
  Comparative experiments of graphene covalently and physically binding CdSe quantum dots to enhance the electron transport in flexible photovoltaic devices
  
  Jung, Mi-Hee; Chu, Moo-Jung
  
  Nanoscale (2014), 6 (15), 9241-9249CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  In this research, we prepd. composite films via covalent coupling of CdSe quantum dots (QDs) to graphene through the direct binding of aryl radicals to the graphene surface. To compare the carrier transport with the CdSe aryl binding graphene film, we prepd. CdSe pyridine capping graphene films through the pi-pi interactions of noncovalent bonds between the graphene and pyridine mols. The photovoltaic devices were fabricated from the two hybrid films using the electrophoretic deposition method on flexible substrates. Even though the two hybrid films have the same amt. of QDs and graphene, time-resolved fluorescence emission decay results show that the emission lifetime of the CdSe aryl group binding graphene film is significantly shorter than that of the pyridine capping CdSe-graphene. The quantum efficiency and photocurrent d. of the device fabricated from CdSe aryl binding graphene were also higher than those of the device fabricated from pyridine capping CdSe-graphene. These results indicated that the carrier transport of the QD-graphene system is not related to the additive effect from the CdSe and graphene components but rather is a result of the unique interactions between the graphene and QDs. We could expect that these results can be useful in designing QD-graphene composite materials, which are applied in photovoltaic devices.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVOitbvP&md5=3fe052de871b00626fee1afb0dc8107c
320. 320
  Guo, S.; Bao, D.; Upadhyayula, S.; Wang, W.; Guvenc, A. B.; Kyle, J. R.; Hosseinibay, H.; Bozhilov, K. N.; Vullev, V. I.; Ozkan, C. S. Photoinduced Electron Transfer Between Pyridine Coated Cadmium Selenide Quantum Dots and Single Sheet Graphene Adv. Funct. Mater. 2013, 23, 5199– 5211 DOI: 10.1002/adfm.201203652
  
  320
  Photoinduced electron transfer between pyridine coated cadmium selenide quantum dots and single sheet graphene
  
  Guo, Shirui; Bao, Duoduo; Upadhyayula, Srigokul; Wang, Wei; Guvenc, Ali B.; Kyle, Jennifer R.; Hosseinibay, Hamed; Bozhilov, Krassimir N.; Vullev, Valentine I.; Ozkan, Cengiz S.; Ozkan, Mihrimah
  
  Advanced Functional Materials (2013), 23 (41), 5199-5211CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Interest in graphene as a two-dimensional quantum-well material for energy applications and nanoelectronics has increased exponentially in the last few years. The recent advances in large-area single-sheet fabrication of pristine graphene have opened unexplored avenues for expanding from nano- to meso-scale applications. The relatively low level of absorptivity and the short lifetimes of excitons of single-sheet graphene suggest that it needs to be coupled with light sensitizers in order to explore its feasibility for photonic applications, such as solar-energy conversion. Red-emitting CdSe quantum dots are employed for photosensitizing single-sheet graphene with areas of several square centimeters. Pyridine coating of the quantum dots not only enhances their adhesion to the graphene surface, but also provides good electronic coupling between the CdSe and the two-dimensional carbon allotrope. Illumination of the quantum dots led to injection of n-carrier in the graphene phase. Time-resolved spectroscopy reveals three modes of photoinduced electron transfer between the quantum dots and the graphene occurring in the femtosecond and picosecond time-domains. Transient absorption spectra provide evidence for photoinduced hole-shift from the CdSe to the pyridine ligands, thereby polarizing the surface of the quantum dots. That is, photoinduced elec. polarization, which favors the simultaneous electron transfer from the CdSe to the graphene phase. These mechanistic insights into the photoinduced interfacial charge transfer have a promising potential to serve as guidelines for the design and development of composites of graphene and inorg. nanomaterials for solar-energy conversion applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXnt1SjsL0%253D&md5=fc0da7cbaaeb65e2809fa6c5edb592d0
321. 321
  Hirose, T.; Kutsuma, Y.; Kurita, A.; Kaneko, T.; Tamai, N. Blinking Suppression of CdTe Quantum Dots on Epitaxial Graphene and the Analysis with Marcus Electron Transfer Appl. Phys. Lett. 2014, 105, 083102 DOI: 10.1063/1.4893667
  
  There is no corresponding record for this reference.
322. 322
  Liu, J.; Kumar, P.; Hu, Y.; Cheng, G. J.; Irudayaraj, J. Enhanced Multiphoton Emission from CdTe/ZnS Quantum Dots Decorated on Single-Layer Graphene J. Phys. Chem. C 2015, 119, 6331– 6336 DOI: 10.1021/jp5123147
  
  There is no corresponding record for this reference.
323. 323
  Qin, J.; Wang, X.; Cao, M.; Hu, C. Germanium Quantum Dots Embedded in N-Doping Graphene Matrix with Sponge-Like Architecture for Enhanced Performance in Lithium-Ion Batteries Chem. - Eur. J. 2014, 20, 9675– 9682 DOI: 10.1002/chem.201402151
  
  323
  Germanium Quantum Dots Embedded in N-Doping Graphene Matrix with Sponge-Like Architecture for Enhanced Performance in Lithium Ion Batteries
  
  Qin, Jinwen; Wang, Xia; Cao, Minhua; Hu, Changwen
  
  Chemistry - A European Journal (2014), 20 (31), 9675-9682CODEN: CEUJED; ISSN:0947-6539. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Germanium quantum dots embedded in a nitrogen-doped graphene matrix with a sponge-like architecture (Ge/GN sponge) are prepd. through a simple and scalable synthetic method, involving freeze drying to obtain the Ge(OH)4/graphene oxide (GO) precursor and subsequent heat redn. treatment. Upon application as an anode for the lithium-ion battery (LIB), the Ge/GN sponge exhibits a high discharge capacity compared with previously reported N-doped graphene. The electrode with the as-synthesized Ge/GN sponge can deliver a capacity of 1258 mAh g-1 even after 50 charge/discharge cycles. This improved electrochem. performance can be attributed to the pore memory effect and highly conductive N-doping GN matrix from the unique sponge-like structure.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtFWns77L&md5=490e504f4cf85d6c062e11bbd25fd6d7
324. 324
  Sun, X.; Zhou, C.; Xie, M.; Sun, H.; Hu, T.; Lu, F.; Scott, S. M.; George, S. M.; Lian, J. Synthesis of ZnO Quantum Dot/Graphene Nanocomposites by Atomic Layer Deposition with High Lithium Storage Capacity J. Mater. Chem. A 2014, 2, 7319– 7326 DOI: 10.1039/C4TA00589A
  
  324
  Synthesis of ZnO quantum dot/graphene nanocomposites by atomic layer deposition with high lithium storage capacity
  
  Sun, Xiang; Zhou, Changgong; Xie, Ming; Sun, Hongtao; Hu, Tao; Lu, Fengyuan; Scott, Spencer M.; George, Steven M.; Lian, Jie
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (20), 7319-7326CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Zinc oxide, as an inexpensive anode material, has attracted less attention than other metal oxides due to its poor cycling stability. A rational design of ZnO nanostructures with well-controlled particle sizes and microstructures is essential to improve their stability and performance as electrodes for lithium ion batteries (LIBs). Here, we demonstrate a simple approach via at. layer deposition (ALD) to synthesize ZnO quantum dots (QDs) on graphene layers, in which the size of the ZnO QDs can be controlled from 2 to 7 nm by ALD cycles. A strong relationship between size and electrochem. performance is obsd., in which smaller sized QDs on graphene display enhanced electrochem. performance. A high reversible specific capacity of 960 mA.h.g-1 is achieved at a c.d. of 100 mA.g-1 for 2 nm ZnO QDs, approaching to the theor. value of ZnO as the LIB anode. The greatly enhanced cycling stability and rate performance of the ALD ZnO QD/graphene composite electrode can be attributed to the well-maintained structural integrity without pulverization upon electrochem. charge/discharge for ZnO QDs with the grain size below a crit. value.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXmslGrt78%253D&md5=03d17e20e7f98cee0ab380876013ebae
325. 325
  Zhou, X.; Shi, J.; Liu, Y.; Su, Q.; Zhang, J.; Du, G. Microwave Irradiation Synthesis of Co₃O₄ Quantum Dots/Graphene Composite as Anode Materials for Li-Ion Battery Electrochim. Acta 2014, 143, 175– 179 DOI: 10.1016/j.electacta.2014.08.023
  
  325
  Microwave irradiation synthesis of Co3O4 quantum dots/graphene composite as anode materials for Li-ion battery
  
  Zhou, Xiaoyan; Shi, Jingjing; Liu, Ya; Su, Qingmei; Zhang, Jun; Du, Gaohui
  
  Electrochimica Acta (2014), 143 (), 175-179CODEN: ELCAAV; ISSN:0013-4686. (Elsevier Ltd.)
  
  Co3O4 quantum dots/graphene composites were synthesized by a facile and efficient microwave irradn. method, and they were analyzed using XRD, TEM, HRTEM, and TG. Uniform Co3O4 nanocrystals of ∼3-8 nm with a high d. are homogeneously dispersed on graphene nanosheets. When used as anode materials for Li-ion batteries, the Co3O4 quantum dots/graphene composites show a significantly enhanced cycling performance (1785 mAh g-1 at 0.1 C after 90 cycles) as well as high rate capability (485 mAh g-1 at 5 C). The reversible capacity is much higher than the theor. value. The superior performance could be attributed to the interfacial Li-storage and the quantum and size effects of quantum dots that lead to high activity during the lithiation/delithiation process. The flexible and conductive graphene nanosheets and well dispersed Co3O4 nanodots as well as the synergetic effect between them also benefit the electrochem. performance by endowing a superior high surface area and shortening the diffusion pathway of Li ions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVakur7I&md5=27278aea1b6efbc2f50916ee72a460a2
326. 326
  Zhao, S.; Xie, D.; Yu, X.; Su, Q.; Zhang, J.; Du, G. Facile Synthesis of Fe₃O₄@C Quantum Dots/Graphene Nanocomposite with Enhanced Lithium-Storage Performance Mater. Lett. 2015, 142, 287– 290 DOI: 10.1016/j.matlet.2014.12.051
  
  326
  Facile synthesis of Fe3O4@C quantum dots/graphene nanocomposite with enhanced lithium-storage performance
  
  Zhao, Saihua; Xie, Dong; Yu, Xudong; Su, Qingmei; Zhang, Jun; Du, Gaohui
  
  Materials Letters (2015), 142 (), 287-290CODEN: MLETDJ; ISSN:0167-577X. (Elsevier B.V.)
  
  Carbon-coated Fe3O4 quantum dots/graphene composite was prepd. by a hydrothermal and calcining process. X-ray diffraction and TEM anal. revealed that carbon-coated Fe3O4 quantum dots with a size around 7-10 nm were distributed uniformly on graphene nanosheets. The carbon shell can preserve structural stabilization of Fe3O4 nanoparticles by preventing the aggregation and buffering the vol. expansion during charge/discharge processes. In addn., the graphene nanosheets formed a three-dimensional network for the transportation of Li+ ions and electrons. When evaluated as anode material for lithium-ion batteries, the nanocomposite showed an improved lithium-storage performance with high cycling stability and good rate capacity. Furthermore, it exhibited an initial discharge capacity of 1300 mA-h/g and retained a reversible capacity of about 940 mA-h/g after 100 cycles at a c.d. of 150 mA/g.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFygt7%252FP&md5=6341530236522502ac2c442c0b9c7c90
327. 327
  Wei, W.; Yang, S.; Zhou, H.; Lieberwirth, I.; Feng, X.; Müllen, K. 3D Graphene Foams Cross-linked with Pre-encapsulated Fe₃O₄ Nanospheres for Enhanced Lithium Storage Adv. Mater. 2013, 25, 2909– 2914 DOI: 10.1002/adma.201300445
  
  327
  3D Graphene Foams Cross-linked with Pre-encapsulated Fe3O4 Nanospheres for Enhanced Lithium Storage
  
  Wei, Wei; Yang, Shubin; Zhou, Haixin; Lieberwirth, Ingo; Feng, Xinliang; Muellen, Klaus
  
  Advanced Materials (Weinheim, Germany) (2013), 25 (21), 2909-2914CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  The three-dimensional graphene/Fe3O4 foams consisting of interior graphene-encapsulated Fe3O4 NSs and exterior porous graphene networks were fabricated. Such a unique architecture established by graphene sheets provides double protection against the aggregation and vol. changes of Fe3O4 active materials, and ensures favorable transport kinetics for both electrons and lithium ions. As a consequence, superior cycling performance (1059 mAh g-1 over 150 cycles) and excellent rate capability (363 mAhg-1 at 4800 mA g-1) were achieved when Fe3O4@GS/GF was used as anode material for lithium storage. Such a protocol to construct 3D hierarchical graphene frameworks can be further extended to other metals or metal oxides for electrochem. energy storage and conversion applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXmtleisrc%253D&md5=931270e7e70a42c0ee14a39cfe9e7af9
328. 328
  Tayyebi, A.; Tavakoli, M. M.; Outokesh, M.; Shafiekhani, A.; Simchi, A. Supercritical Synthesis and Characterization of Graphene-PbS Quantum Dots Composite with Enhanced Photovoltaic Properties Ind. Eng. Chem. Res. 2015, 54, 7382– 7392 DOI: 10.1021/acs.iecr.5b00008
  
  328
  Supercritical Synthesis and Characterization of Graphene-PbS Quantum Dots Composite with Enhanced Photovoltaic Properties
  
  Tayyebi, Ahmad; Tavakoli, Mohammad Mahdi; Outokesh, Mohammad; Shafiekhani, Azizollah; Simchi, Abdolreza
  
  Industrial & Engineering Chemistry Research (2015), 54 (30), 7382-7392CODEN: IECRED; ISSN:0888-5885. (American Chemical Society)
  
  Lead sulfide quantum dots (PbS QDs) were decorated onto a graphene surface in a semi-core-shell structure using supercrit. EtOH. The temp. of EtOH played significant role in controlling size and agglomeration of QDs as well as the extent of redn. of graphene. Av. size of the QDs was estd. by TEM to be around 3.96 nm and by quantum models to be ∼4.34 nm. PbS QDs prepd. at 330° were of high purity, and the yield was 99%. Instrumental and chem. analyses demonstrated formation of a strong bond between PbS QDs and graphene, through a Pb-O-C bridge. UV and photoluminescence measurements along with theor. considerations revealed that integration of PbS QDs with graphene results in efficient sepn. of the electron-hole, thus enhancing photo → elec. energy conversion. This outcome was further evidenced by comparison of performance of PbS/G in a solar cell, with the performance of pristine PbS QDs.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtFSrtLbF&md5=e3ea4ee05700a1dd3f008d13cbbc2bcd
329. 329
  Gao, H.; Shangguan, W.; Hu, G.; Zhu, K. Preparation and Photocatalytic Performance of Transparent Titania Film from Monolayer Titania Quantum Dots Appl. Catal., B 2016, 180, 416– 423 DOI: 10.1016/j.apcatb.2015.06.049
  
  329
  Preparation and photocatalytic performance of transparent titania film from monolayer titania quantum dots
  
  Gao, Hanyang; Shangguan, Wenfeng; Hu, Guoxin; Zhu, Kunxu
  
  Applied Catalysis, B: Environmental (2016), 180 (), 416-423CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)
  
  By using monolayer titania quantum dots (MTQDs) colloid, a continuous and transparent ultrathin titania film was prepd. simply by drop-cast metals or spray coating process method at room temp. The formation of this even and ultrathin film was not only because of the very thin thickness of two-dimensional MTQDs, but also because of the suppression of coffee-ring effect. The self-assembly behaviors of MTQDs were examd. by AFM and the reason for the suppression of coffee-ring effect was discussed in detail. Furthermore, the photocatalytic performance of this MTQDs film was evaluated and an improvement was achieved by loading graphene. Comparison between MTQDs/graphene composite and sphere-shaped nanoTiO2/graphene composite indicated that, the face-to-face contact mode between MTQDs and graphene may contribute to the high activity of MTQDs/graphene composite.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtFGksLrP&md5=c946cb15c0d94a99490860cacd137c8d
330. 330
  Cao, S.; Chen, C.; Zhang, J.; Zhang, C.; Yu, W.; Liang, B.; Tsang, Y. MnO_x Quantum Dots Decorated Reduced Graphene Oxide/TiO₂ Nanohybrids for Enhanced Activity by a UV Pre-Catalytic Microwave Method Appl. Catal., B 2015, 176–177, 500– 512 DOI: 10.1016/j.apcatb.2015.04.041
  
  330
  MnOx quantum dots decorated reduced graphene oxide/TiO2 nanohybrids for enhanced activity by a UV pre-catalytic microwave method
  
  Cao, Shiyi; Chen, Chuansheng; Zhang, Juyan; Zhang, Cui; Yu, Weiwei; Liang, Bo; Tsang, Yuenhong
  
  Applied Catalysis, B: Environmental (2015), 176-177 (), 500-512CODEN: ACBEE3; ISSN:0926-3373. (Elsevier B.V.)
  
  Graphene/TiO2-based catalysts have attracted much attention as promising photocatalysts because of their low cost and excellent performance. In this report, we integrated the energy storage with high photocatalytic activity into a new simulation, physicochem. for wider applications in the field of energy utilization and environmental treatment. The MnOx quantum dots were decorated on reduced graphene oxide/TiO2 hybrids (GTM) by combining UV excitation with microwave method for the first time. Exptl. results show that GTM nanohybrids have excellent photocatalytic activity for org. dyes under UV-vis light and good antibacterial activity. Besides, UV preexcitation can improve the adsorbability and photocatalytic durability of GTM nanohybrids for high-concn. dyes. These enhancements are attributed to the rapid sepn. of photogenerated carriers from reduced graphene oxide and surface defects induced by UV excitation, and the broad light absorption aroused by the narrow band gap and MnOx quantum dots simultaneously.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmvFamu7g%253D&md5=9f32f3a2d078fb9503f8ea5fc46cbab2
331. 331
  Kaur, P.; Shin, M. S.; Sharma, N.; Kaur, N.; Joshi, A.; Chae, S. R.; Park, J. S.; Kang, M. S.; Sekhon, S. S. Non-Covalent Functionalization of Graphene with Poly(diallyl dimethylammonium) Chloride: Effect of a Non-Ionic Surfactant Int. J. Hydrogen Energy 2015, 40, 1541– 1547 DOI: 10.1016/j.ijhydene.2014.11.068
  
  331
  Non-covalent functionalization of graphene with poly(diallyl dimethylammonium) chloride: Effect of a non-ionic surfactant
  
  Kaur, Prabhsharan; Shin, Mun-Sik; Sharma, Neha; Kaur, Namarta; Joshi, Anjali; Chae, So-Ryong; Park, Jin-Soo; Kang, Moon-Sung; Sekhon, Satpal Singh
  
  International Journal of Hydrogen Energy (2015), 40 (3), 1541-1547CODEN: IJHEDX; ISSN:0360-3199. (Elsevier Ltd.)
  
  Carbon based nanomaterials (carbon nanotubes, graphene etc) contg. various hetero atoms are promising metal free catalysts for oxygen redn. reaction in fuel cells. We report the non-covalent functionalization of graphene with poly(diallyl dimethylammonium) chloride (PDDA), a polyelectrolyte contg. nitrogen, using a very simple method. The addn. of a non-ionic surfactant (Triton X-100) during functionalization has been obsd. to improve the interactions between graphene and PDDA. An up-shift in the position of G-peak in the Raman spectra, down-shift in the binding energy (B.E.) of N1s peak and an up-shift in the B.E. of C1s peak in XPS spectra have been obsd. due to an inter-mol. charge-transfer from carbon in graphene to nitrogen in PDDA, which get enhanced in the presence of Triton X-100. Graphene functionalized with PDDA also show good thermal stability. The addn. of a non-ionic surfactant enhances the non-covalent functionalization of graphene with PDDA, which is desirable from applications point of view.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVWrs7vN&md5=bec41842f02b35476f517bee331304f0
332. 332
  Tiwari, J. N.; Tiwari, R. N.; Kim, K. S. Zero-Dimensional, One-Dimensional, Two-Dimensional and Three-Dimensional Nanostructured Materials for Advanced Electrochemical Energy Devices Prog. Mater. Sci. 2012, 57, 724– 803 DOI: 10.1016/j.pmatsci.2011.08.003
  
  332
  Zero-dimensional, one-dimensional, two-dimensional and three-dimensional nanostructured materials for advanced electrochemical energy devices
  
  Tiwari, Jitendra N.; Tiwari, Rajanish N.; Kim, Kwang S.
  
  Progress in Materials Science (2012), 57 (4), 724-803CODEN: PRMSAQ; ISSN:0079-6425. (Elsevier Ltd.)
  
  A review. One of the biggest challenges of 21st century is to develop powerful electrochem. energy devices (EEDs). The EEDs such as fuel cells, supercapacitors, and Li-ion batteries are among the most promising candidates in terms of power-densities and energy-densities. The nanostructured materials (NSMs) have drawn intense attention to develop highly efficient EEDs because of their high surface area, novel size effects, significantly enhanced kinetics, and so on. In this review article, we briefly introduce general synthesis, fabrication and their classification as zero-dimensional (0D), one dimensional (1D), two-dimensional (2D) and three-dimensional (3D) NSMs. Subsequently, we focus an attention on recent progress in advanced NSMs as building blocks for EEDs (such as fuel cells, supercapacitors, and Li-ion batteries) based on investigations at the 0D, 1D, 2D and 3D NSMs.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XitFCrsr4%253D&md5=8c3a4c5282cef7f9b87005af5769bba5
333. 333
  Tiwari, J. N.; Tiwari, R. N.; Singh, G.; Kim, K. S. Recent Progress in the Development of Anode and Cathode Catalysts for Direct Methanol Fuel Cells Nano Energy 2013, 2, 553– 578 DOI: 10.1016/j.nanoen.2013.06.009
  
  333
  Recent progress in the development of anode and cathode catalysts for direct methanol fuel cells
  
  Tiwari, Jitendra N.; Tiwari, Rajanish N.; Singh, Gyan; Kim, Kwang S.
  
  Nano Energy (2013), 2 (5), 553-578CODEN: NEANCA; ISSN:2211-2855. (Elsevier Ltd.)
  
  A review. Continuous growth in global energy demand has sparked concerns about energy security and environmental sustainability. In the past two decades, attempts have been made in the development of innovative energy technologies. The direct methanol fuel cell (DMFC) is among the most promising alternative energy sources for the near future. Simple construction, compact design, high energy d. and relatively high energy-conversion efficiency give the DMFC an advantage over other promising power sources in terms of portability. However, the translation of DMFCs into com. successful products is precluded due to poor performance. In addn., low activity, poor durability and reliability and an expensive anode and cathode further discourage the application of DMFCs. In this regard, the present review article focuses on recent progress in the development of anode and cathode catalysts for DMFCs. The first part of the review discusses the recent developments in the synthesis of single-, double-, and multiple-component catalysts and new catalyst supports for anode electrodes. The section is followed by the chem. approaches employed to make alloys and composite catalysts, aiming to enhance their activity, reliability and durability for the methanol oxidn. reaction. Finally, exciting new research that pushes the development of single-, double-, and multiple-component catalysts and new catalyst supports for cathode electrodes is introduced. In addn., size-, shape- and compn.-dependent electrocatalysts that are advocated for methanol oxidn. at the anode and oxygen redn. at the cathode are highlighted to illustrate the potential of the newly developed electrocatalysts for DMFC applications. Moreover, this article provides a comprehensive review of the exptl. work that is devoted to understanding the fundamental problems and recent progress in the development of anode and cathode catalysts for DMFCs.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhs1WhsbvJ&md5=af8df026389549837b50e7fb4e296806
334. 334
  Tiwari, J. N.; Tiwari, R. N.; Chang, Y.-M.; Lin, K.-L. A Promising Approach to the Synthesis of 3D Nanoporous Graphitic Carbon as a Unique Electrocatalyst Support for Methanol Oxidation ChemSusChem 2010, 3, 460– 466 DOI: 10.1002/cssc.200900223
  
  There is no corresponding record for this reference.
335. 335
  Tiwari, J. N.; Tiwari, R. N.; Singh, G.; Lin, K.-L. Direct Synthesis of Vertically Interconnected 3-D Graphitic Nanosheets on Hemispherical Carbon Particles by Microwave Plasma CVD Plasmonics 2011, 6, 67– 73 DOI: 10.1007/s11468-010-9170-7
  
  335
  Direct synthesis of vertically interconnected 3-D graphitic nanosheets on hemispherical carbon particles by microwave plasma CVD
  
  Tiwari, Jitendra N.; Tiwari, Rajanish N.; Singh, Gyan; Lin, Kun-Lin
  
  Plasmonics (2011), 6 (1), 67-73CODEN: PLASCS; ISSN:1557-1955. (Springer)
  
  High-quality, free-standing, and vertically interconnected three-dimensional (3-D) graphitic nanosheets (GNSs) were synthesized over the surface of hemispherical carbon particles/GaN at 700 °C by microwave plasma chem. vapor deposition (CVD) in presence of methane gas, whereas the hemispherical carbon particles have been directly deposited on GaN/sapphire template. The GNSs are ∼1-5 nm in thickness and have a graphitic flake structure on hemispherical carbon particles. The vertically interconnected 3-D GNSs on hemispherical carbon particles have been characterized by SEM, transmission electron microscopy, selective area electron diffraction pattern, X-ray diffraction, at. force microscopy, Raman spectroscopy, XPS, and nitrogen gas adsorption-Brunauer-Emmet-Teller. The present CVD approach is capable of producing large quantities of GNSs with high purity. Moreover, a high-purity free-standing and vertically interconnected 3-D GNSs on hemispherical carbon particles have an enormous potential for applications in electronic devices, biol. sensors, gas uptake and storage, fuel cells, lithium ion batteries, and more.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXjs1Ckur0%253D&md5=dcb05e4c7667069f9b259383a1b59b3b
336. 336
  Dubey, P.; Kumar, A.; Prakash, R. Non-Covalent Functionalization of Graphene Oxide by Polyindole and Subsequent Incorporation of Ag Nanoparticles for Electrochemical Applications Appl. Surf. Sci. 2015, 355, 262– 267 DOI: 10.1016/j.apsusc.2015.07.079
  
  There is no corresponding record for this reference.
337. 337
  Campbell, P. G.; Merrill, M. D.; Wood, B. C.; Montalvo, E.; Worsley, M. A.; Baumann, T. F.; Biener, J. Battery/Supercapacitor Hybrid via Non-Covalent Functionalization of Graphene Macro-Assemblies J. Mater. Chem. A 2014, 2, 17764– 17770 DOI: 10.1039/C4TA03605K
  
  337
  Battery/supercapacitor hybrid via non-covalent functionalization of graphene macro-assemblies
  
  Campbell, P. G.; Merrill, M. D.; Wood, B. C.; Montalvo, E.; Worsley, M. A.; Baumann, T. F.; Biener, J.
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (42), 17764-17770CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Binder-free, monolithic, high surface area graphene macro-assemblies (GMAs) are promising materials for supercapacitor electrodes, but, like all graphitic carbon based supercapacitor electrodes, still lack sufficient energy d. for demanding practical applications. Here, we demonstrate that the energy storage capacity of GMAs can be increased nearly 3-fold (up to 23 W h kg-1) by facile, non-covalent surface modification with anthraquinone (AQ). AQ provides battery-like redox charge storage (927 C g-1) without affecting the cond. and capacitance of the GMA support. The resulting AQ-GMA battery/supercapacitor hybrid electrodes demonstrate excellent power performance, show remarkable long-term cycling stability and, by virtue of their excellent mech. properties, allow for further increases in volumetric energy d. by mech. compression of the treated electrode. Our measured capacity is very close to the theor. max. obtained using detailed d. functional theory calcns., suggesting nearly all incorporated AQ is made available for charge storage.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1Squ7bM&md5=90e347066809e50539b2e2de56020f51
338. 338
  Kong, D.; He, H.; Song, Q.; Wang, B.; Lv, W.; Yang, Q.-H.; Zhi, L. Rational Design of MoS₂@Graphene Nanocables: Towards High Performance Electrode Materials for Lithium Ion Batteries Energy Environ. Sci. 2014, 7, 3320– 3325 DOI: 10.1039/C4EE02211D
  
  338
  Rational design of MoS2@graphene nanocables: towards high performance electrode materials for lithium ion batteries
  
  Kong, Debin; He, Haiyong; Song, Qi; Wang, Bin; Lv, Wei; Yang, Quan-Hong; Zhi, Linjie
  
  Energy & Environmental Science (2014), 7 (10), 3320-3325CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)
  
  Here, we have successfully developed a novel contact mode between MoS2 and graphene, where graphene rolls up into a hollow nanotube and thin MoS2 nanosheets are uniformly standing on the inner surface of graphitic nanotubes, thus forming mech. robust, free-standing, interwoven MoS2@graphene nanocable webs (MoS2@G). Such a hybrid structure can maximize the MoS2 loading in the electrode in which over 90% of MoS2 nanosheets with stacked layer no. of less than 5 can be installed. Remarkably, when calcd. on the basis of the whole electrode, this binder free electrode not only shows high specific capacity (ca. 1150 mA h g-1) and excellent cycling performance (almost 100% capacity retention even after 160 cycles at a c.d. of 0.5 A g-1) but exhibits a surprisingly high-rate capability of 700 mA h g-1 at the rate of 10 A g-1 despite such a high MoS2 loading content, which is one of the best results of MoS2-based electrode materials ever reported thus far.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtlWrt77J&md5=9a459b5666a7d3606a7dde98134859af
339. 339
  Yang, S.; Cao, C.; Huang, P.; Peng, L.; Sun, Y.; Wei, F.; Song, W. Sandwich-Like Porous TiO₂/Reduced Graphene Oxide (rGO) for High-Performance Lithium-Ion Batteries J. Mater. Chem. A 2015, 3, 8701– 8705 DOI: 10.1039/C5TA01744K
  
  339
  Sandwich-like porous TiO2/reduced graphene oxide (rGO) for high-performance lithium-ion batteries
  
  Yang, Shuliang; Cao, Changyan; Huang, Peipei; Peng, Li; Sun, Yongbin; Wei, Fang; Song, Weiguo
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (16), 8701-8705CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Sandwich-like porous TiO2/reduced graphene oxide (rGO) composites were prepd. through a facile solvothermal method. These composites with porous structures and high elec. cond. showed high capacity, rate capability and cycling stability when used as an anode electrode material for lithium ion batteries. A reversible capacity of 206 mA h g-1 can be retained at a current rate of 0.1 A g-1 after 200 charge-discharge cycles. Remarkably, a high reversible capacity of ∼128 mA h g-1 at a c.d. of 5 A g-1 can be obtained.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXks1aht70%253D&md5=f9d3ba32270954655275205fe1fac202
340. 340
  Ali, G.; Oh, S. H.; Kim, S. Y.; Kim, J. Y.; Cho, B. W.; Chung, K. Y. An Open-Framework Iron Fluoride and Reduced Graphene Oxide Nanocomposite as a High-Capacity Cathode Material for Na-Ion Batteries J. Mater. Chem. A 2015, 3, 10258– 10266 DOI: 10.1039/C5TA00643K
  
  340
  An open-framework iron fluoride and reduced graphene oxide nanocomposite as a high-capacity cathode material for Na-ion batteries
  
  Ali, Ghulam; Oh, Si Hyoung; Kim, Se Young; Kim, Ji Young; Cho, Byung Won; Chung, Kyung Yoon
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (19), 10258-10266CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Cathode materials with high capacity and good stability for rechargeable Na-ion batteries (NIBs) are few in no. Here, a composite is reported of electrochem. active iron fluoride hydrate and reduced graphene oxide (rGO) as a promising cathode material for NIBs. Phase-pure FeF3·0.5H2O is synthesized by a non-aq. pptn. method and a composite with rGO is prepd. to enhance the elec. cond. The encapsulation of FeF3·0.5H2O nanoparticles between the rGO layers results in a lightwt. and stable electrode with a three-dimensional network. The composite material delivers a substantially enhanced discharge capacity of 266 mA h g-1 compared to 158 mA h g-1 of the bare FeF3·0.5H2O at a c.d. of 0.05 C. This composite also shows a stable cycle performance with a high capacity retention of > 86% after 100 cycles, demonstrating its potential as a cathode material for NIBs.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjtFSisbw%253D&md5=22ea89a10b65e3facd89e95f1b2e037b
341. 341
  David, L.; Bhandavat, R.; Singh, G. MoS₂/Graphene Composite Paper for Sodium-Ion Battery Electrodes ACS Nano 2014, 8, 1759– 1770 DOI: 10.1021/nn406156b
  
  341
  MoS2/Graphene Composite Paper for Sodium-Ion Battery Electrodes
  
  David, Lamuel; Bhandavat, Romil; Singh, Gurpreet
  
  ACS Nano (2014), 8 (2), 1759-1770CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  We study the synthesis and electrochem. and mech. performance of layered free-standing papers composed of acid-exfoliated few-layer molybdenum disulfide (MoS2) and reduced graphene oxide (rGO) flakes for use as a self-standing flexible electrode in sodium-ion batteries. Synthesis was achieved through vacuum filtration of homogeneous dispersions consisting of varying wt. percent of acid-treated MoS2 flakes in GO in DI water, followed by thermal redn. at elevated temps. The electrochem. performance of the crumpled composite paper (at 4 mg.cm-2) was evaluated as counter electrode against pure Na foil in a half-cell configuration. The electrode showed good Na cycling ability with a stable charge capacity of ∼230 mAh.g-1 with respect to total wt. of the electrode with Coulombic efficiency reaching ∼99%. In addn., static uniaxial tensile tests performed on crumpled composite papers showed high av. strain to failure reaching ∼2%.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXpslejsw%253D%253D&md5=d45da3902a48ed0a91ed1278d69862fb
342. 342
  Hu, C.; Zheng, G.; Zhao, F.; Shao, H.; Zhang, Z.; Chen, N.; Jiang, L.; Qu, L. A Powerful Approach to Functional Graphene Hybrids for High Performance Energy-Related Applications Energy Environ. Sci. 2014, 7, 3699– 3708 DOI: 10.1039/C4EE01876A
  
  342
  A powerful approach to functional graphene hybrids for high performance energy-related applications
  
  Hu, Chuangang; Zheng, Guanpei; Zhao, Fei; Shao, Huibo; Zhang, Zhipan; Chen, Nan; Jiang, Lan; Qu, Liangti
  
  Energy & Environmental Science (2014), 7 (11), 3699-3708CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)
  
  Pore-rich graphene networks hold great promise as advanced supporting materials of metals and metal oxides for high electrochem. performance. In this work, a dual substrate-assisted redn. and assembly (DSARA) process has been devised and demonstrated as a general approach for the spontaneous redn. of graphene oxide, well-organized assembly of reduced graphene oxide into three-dimensional porous networks, and simultaneous functionalization of graphenes with metal-based nanocomponents on demand, including metals, metal oxides, metal/metal oxide hybrids or alloys. The newly designed process avoids the use of toxic reducing agents, multiple steps, and long reaction times, and offers a facile but powerful pathway to greatly enhance the merits of using pristine graphenes in energy-related applications such as lithium ion batteries, fuel cells, photoelec. conversion devices, and so on. Specifically, as an anode material in a lithium ion battery (LIB), the DSARA-produced RGO decorated with NiO/Ni nanohybrids presents a record capacity with a high charge-discharge rate compared to those reported so far for Ni based materials. PdPt alloy nanoparticles on 3D RGO generated by DSARA exhibits a highly efficient catalytic performance for the oxygen redn. reaction (ORR) in fuel cells.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtlOjsLbJ&md5=fdd357d50ca23d3d62e66231005ddf95
343. 343
  Ren, X.; Hu, Z.; Hu, H.; Qiang, R.; Li, L.; Li, Z.; Yang, Y.; Zhang, Z.; Wu, H. Noncovalently-Functionalized Reduced Graphene Oxide Sheets by Water-Soluble Methyl Green for Supercapacitor Application Mater. Res. Bull. 2015, 70, 215– 221 DOI: 10.1016/j.materresbull.2015.04.045
  
  343
  Noncovalently-functionalized reduced graphene oxide sheets by water-soluble methyl green for supercapacitor application
  
  Ren, Xiaoying; Hu, Zhongai; Hu, Haixiong; Qiang, Ruibin; Li, Li; Li, Zhimin; Yang, Yuying; Zhang, Ziyu; Wu, Hongying
  
  Materials Research Bulletin (2015), 70 (), 215-221CODEN: MRBUAC; ISSN:0025-5408. (Elsevier Ltd.)
  
  In the present work, water-sol. electroactive methyl green (MG) has been used to non-covalently functionalize reduced graphene oxide (RGO) for enhancing supercapacitive performance. The microstructure, compn. and morphol. of MG-RGO composites are systematically characterized by UV-vis absorption, field emission SEM (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochem. performances are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochem. impedance spectroscopy (EIS). The fast redox reactions from MG could generate addnl. pseudocapacitance, which endows RGO higher capacitances. As a result, the MG-RGO composite (with the 5:4 mass ratio of MG:RGO) achieve a max. value of 341 F g-1 at 1 A g-1 within the potential range from -0.25 to 0.75 V and provide a 180% enhancement in specific capacitance in comparison with pure RGO. Furthermore, excellent rate capability (72% capacitance retention from 1 A g-1 to 20 A g-1) and long life cycle (12% capacitance decay after 5000 cycles) are achieved for the MG-RGO composite electrode.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXntFGrsb8%253D&md5=7b9ed34edeb221e7019e3bca5efb24ef
344. 344
  Jung, S. M.; Mafra, D. L.; Lin, C.-T.; Jung, H. Y.; Kong, J. Controlled Porous Structures of Graphene Aerogels and Their Effect on Supercapacitor Performance Nanoscale 2015, 7, 4386– 4393 DOI: 10.1039/C4NR07564A
  
  344
  Controlled porous structures of graphene aerogels and their effect on supercapacitor performance
  
  Jung, Sung Mi; Mafra, Daniela Lopes; Lin, Cheng-Te; Jung, Hyun Young; Kong, Jing
  
  Nanoscale (2015), 7 (10), 4386-4393CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  The design and optimization of 3D graphene nanostructures are critically important since the properties of electrochem. energy storages such as supercapacitors can be dramatically enhanced by tunable porous channels. In this work, we have developed porous graphene aerogels from graphene suspensions obtained via electrochem. exfoliation and explored their application as supercapacitor electrodes. By adjusting the content of the electrolyte in the exfoliation process, the aspect ratio of graphene sheets and the porosity of the graphene network can be optimized. Furthermore, the freezing temp. in the freeze drying step is also found to play a crit. role in the resulting pore size distributions of the porous networks. The optimized conditions lead to meso- and macroporous graphene aerogels with a high sp. surface area, extremely low densities and superior elec. properties. As a result, the graphene aerogel supercapacitors exhibit a specific capacitance of 325 F g-1 at 1 A g-1 and an energy d. of 45 Wh kg-1 in a 0.5 M H2SO4 aq. electrolyte with high electrochem. stability and electrode uniformity required for practical usage. This research provides a practical method for lightwt., high-performance and low-cost materials in the effective use of energy storage systems.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXislCjtrk%253D&md5=b777202fe404a63c52d9a6b0c3b0a30c
345. 345
  Jana, M.; Saha, S.; Khanra, P.; Samanta, P.; Koo, H.; Murmu, N. C.; Kuila, T. Non-Covalent Functionalization of Reduced Graphene Oxide Using Sulfanilic Acid Azocromotrop and Its Application as a Supercapacitor Electrode Material J. Mater. Chem. A 2015, 3, 7323– 7331 DOI: 10.1039/C4TA07009G
  
  345
  Non-covalent functionalization of reduced graphene oxide using sulfanilic acid azocromotrop and its application as a supercapacitor electrode material
  
  Jana, Milan; Saha, Sanjit; Khanra, Partha; Samanta, Pranab; Koo, Hyeyoung; Chandra Murmu, Naresh; Kuila, Tapas
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (14), 7323-7331CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Sulfanilic acid azocromotrop (SAC) modified reduced graphene oxide (SAC-RGO) was prepd. by simple noncovalent functionalization of graphene oxide (GO) followed by post redn. using hydrazine monohydrate. Spectral anal. (FTIR, Raman and XPS) revealed that successful modification had occurred of GO with SAC through π-π interaction. The elec. cond. of SAC-RGO is ∼551 S m-1. The capacitive performance of SAC-RGO was recorded using a three electrode set up with 1 (M) aq. H2SO4 as the electrolyte. The -SO3H functionalities of SAC contributed pseudocapacitance as evidenced from the redox peaks (at ∼0.43 and 0.27 V) present in the cyclic voltammetric (CV) curves measured for SAC-RGO. The contribution of elec. double layer capacitance was evidenced from the near rectangular shaped CV curves and resulted in a high specific capacitance of 366 F g-1 at a c.d. of 1.2 A g-1 for SAC-RGO electrode. An asym. device (SAC-RGO//RGO) was designed with SAC-RGO as the pos. electrode and RGO as the neg. electrode. The device showed an energy d. of ∼25.8 W h kg-1 at a power d. of ∼980 W kg-1. The asym. device showed retention in specific capacitance of ∼72% after 5000 charge-discharge cycles. The Nyquist data of the device was fitted with Z-view and different components (soln. resistance, charge-transfer resistance and Warburg elements) were calcd. from the fitted curves.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjt1SksLg%253D&md5=1b356ff31927777e6f79f31d2921d7e4
346. 346
  Hsu, W.-T.; Tsai, Z.-S.; Chen, L.-C.; Chen, G.-Y.; Lin, C.-C.; Chen, M.-H.; Song, J.-M.; Lin, C.-H. Passivation Ability of Graphene Oxide Demonstrated by Two-Different-Metal Solar Cells Nanoscale Res. Lett. 2014, 9, 696 DOI: 10.1186/1556-276X-9-696
  
  There is no corresponding record for this reference.
347. 347
  Kim, K. S.; Zhao, Y.; Jang, H.; Lee, S. Y.; Kim, J. M.; Kim, K. S.; Ahn, J.-H.; Kim, P.; Choi, J.-Y.; Hong, B. H. Large-Scale Pattern Growth of Graphene Films for Stretchable Transparent Electrodes Nature 2009, 457, 706– 710 DOI: 10.1038/nature07719
  
  347
  Large-scale pattern growth of graphene films for stretchable transparent electrodes
  
  Kim, Keun Soo; Zhao, Yue; Jang, Houk; Lee, Sang Yoon; Kim, Jong Min; Kim, Kwang S.; Ahn, Jong-Hyun; Kim, Philip; Choi, Jae-Young; Hong, Byung Hee
  
  Nature (London, United Kingdom) (2009), 457 (7230), 706-710CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)
  
  Problems assocd. with large-scale pattern growth of graphene constitute one of the main obstacles to using this material in device applications. Recently, macroscopic-scale graphene films were prepd. by two-dimensional assembly of graphene sheets chem. derived from graphite crystals and graphene oxides. However, the sheet resistance of these films was found to be much larger than theor. expected values. Here we report the direct synthesis of large-scale graphene films using chem. vapor deposition on thin nickel layers, and present two different methods of patterning the films and transferring them to arbitrary substrates. The transferred graphene films show very low sheet resistance of ∼280 Ω per square, with ∼80% optical transparency. At low temps., the monolayers transferred to silicon dioxide substrates show electron mobility greater than 3,700 cm2 V-1 s-1 and exhibit the half-integer quantum Hall effect, implying that the quality of graphene grown by chem. vapor deposition is as high as mech. cleaved graphene. Employing the outstanding mech. properties of graphene, we also demonstrate the macroscopic use of these highly conducting and transparent electrodes in flexible, stretchable, foldable electronics.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXht1ehtL4%253D&md5=0eef5b83d20b2e74add31eb1aa19337e
348. 348
  Yin, Z.; Zhu, J.; He, Q.; Cao, X.; Tan, C.; Chen, H.; Yan, Q.; Zhang, H. Graphene-Based Materials for Solar Cell Applications Adv. Energy Mater. 2014, 4, 1300574 DOI: 10.1002/aenm.201300574
  
  348
  Graphene-Based Materials for Solar Cell Applications
  
  Yin, Zongyou; Zhu, Jixin; He, Qiyuan; Cao, Xiehong; Tan, Chaoliang; Chen, Hongyu; Yan, Qingyu; Zhang, Hua
  
  Advanced Energy Materials (2014), 4 (1), 1300574/1-1300574/19CODEN: ADEMBC; ISSN:1614-6840. (Wiley-Blackwell)
  
  A review. Graphene has attracted increasing attention due to its unique elec., optical, optoelectronic, and mech. properties, which have opened up huge nos. of opportunities for applications. An overview of the recent research on graphene and its derivs. is presented, with a particular focus on synthesis, properties, and applications in solar cells.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjt1ahug%253D%253D&md5=d8690f67136e7320b8dec889321ceb96
349. 349
  Liu, J.; Xue, Y.; Dai, L. Sulfated Graphene Oxide as a Hole-Extraction Layer in High-Performance Polymer Solar Cells J. Phys. Chem. Lett. 2012, 3, 1928– 1933 DOI: 10.1021/jz300723h
  
  349
  Sulfated Graphene Oxide as a Hole-Extraction Layer in High-Performance Polymer Solar Cells
  
  Liu, Jun; Xue, Yuhua; Dai, Liming
  
  Journal of Physical Chemistry Letters (2012), 3 (14), 1928-1933CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)
  
  In this study, we have rationally designed and successfully developed sulfated graphene oxide (GO-OSO3H) with -OSO3H groups attached to the carbon basal plane of reduced GO surrounded with edge-functionalized -COOH groups. The resultant GO-OSO3H is demonstrated to be an excellent hole extn. layer for polymer solar cells because of its proper work function for ohmic contact with the donor polymer, its reduced basal plane for improving cond., and its -OSO3H/-COOH groups for enhancing soly. for soln. processing. Compared with that of GO, the much improved cond. of GO-OSO3H (1.3 S/m vs. 0.004 S/m) leads to greatly improved fill factor (0.71 vs. 0.58) and power conversion efficiency (4.37% vs. 3.34%) of the resulting polymer solar cell devices. Moreover, the device performance of GO-OSO3H is among the best reported for intensively studied poly(3-hexylthiophene):[6,6]-phenyl-C61 butyric acid Me ester (P3HT:PCBM) devices. Our results imply that judiciously functionalized graphene materials can be used to replace existing hole extn. layer materials for specific device applications with outstanding performance.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XpsVGktb8%253D&md5=b2d93521cbf46d9556445c22f01b3910
350. 350
  Shi, E.; Li, H.; Yang, L.; Zhang, L.; Li, Z.; Li, P.; Shang, Y.; Wu, S.; Li, X.; Wei, J. Colloidal Antireflection Coating Improves Graphene-Silicon Solar Cells Nano Lett. 2013, 13, 1776– 1781
  
  350
  Colloidal antireflection coating improves graphene-silicon solar cells
  
  Shi, Enzheng; Li, Hongbian; Yang, Long; Zhang, Luhui; Li, Zhen; Li, Peixu; Shang, Yuanyuan; Wu, Shiting; Li, Xinming; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai; Fang, Ying; Cao, Anyuan
  
  Nano Letters (2013), 13 (4), 1776-1781CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Carbon nanotube-Si and graphene-Si solar cells have attracted much interest recently owing to their potential in simplifying manufg. process and lowering cost compared to Si cells. Until now, the power conversion efficiency of graphene-Si cells remains under 10% and well below that of the nanotube-Si counterpart. Here, we involved a colloidal antireflection coating onto a monolayer graphene-Si solar cell and enhanced the cell efficiency to 14.5% under std. illumination (air mass 1.5, 100 mW/cm2) with a stable antireflection effect over long time. The antireflection treatment was realized by a simple spin-coating process, which significantly increased the short-circuit c.d. and the incident photon-to-electron conversion efficiency to about 90% across the visible range. Our results demonstrate a great promise in developing high-efficiency graphene-Si solar cells in parallel to the more extensively studied carbon nanotube-Si structures.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXksVyjtro%253D&md5=205bcc03a483f0311f97e4ca17b2543c
351. 351
  Wang, J. T.-W.; Ball, J. M.; Barea, E. M.; Abate, A.; Alexander-Webber, J. A.; Huang, J.; Saliba, M.; Mora-Sero, I.; Bisquert, J.; Snaith, H. J. Low-Temperature Processed Electron Collection Layers of Graphene/TiO₂ Nanocomposites in Thin Film Perovskite Solar Cells Nano Lett. 2014, 14, 724– 730 DOI: 10.1021/nl403997a
  
  351
  Low-Temperature Processed Electron Collection Layers of Graphene/TiO2 Nanocomposites in Thin Film Perovskite Solar Cells
  
  Wang, Jacob Tse-Wei; Ball, James M.; Barea, Eva M.; Abate, Antonio; Alexander-Webber, Jack A.; Huang, Jian; Saliba, Michael; Mora-Sero, Ivan; Bisquert, Juan; Snaith, Henry J.; Nicholas, Robin J.
  
  Nano Letters (2014), 14 (2), 724-730CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  The highest efficiencies in soln.-processable perovskite-based solar cells were achieved using an electron collection layer that requires sintering at 500°. This is unfavorable for low-cost prodn., applications on plastic substrates, and multijunction device architectures. Here we report a low-cost, soln.-based deposition procedure utilizing nanocomposites of graphene and TiO2 nanoparticles as the electron collection layers in meso-superstructured perovskite solar cells. The graphene nanoflakes provide superior charge-collection in the nanocomposites, enabling the entire device to be fabricated at temps. no higher than 150°. These solar cells show remarkable photovoltaic performance with a power conversion efficiency up to 15.6%. This work demonstrates that graphene/metal oxide nanocomposites have the potential to contribute significantly toward the development of low-cost solar cells.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvFejtLzO&md5=9ffbefc7f6b685213e328c6e0bc03930
352. 352
  Kim, H.; Mattevi, C.; Kim, H. J.; Mittal, A.; Mkhoyan, K. A.; Riman, R. E.; Chhowalla, M. Optoelectronic Properties of Graphene Thin Films Deposited by a Langmuir-Blodgett Assembly Nanoscale 2013, 5, 12365– 12374 DOI: 10.1039/c3nr02907g
  
  352
  Optoelectronic properties of graphene thin films deposited by a Langmuir-Blodgett assembly
  
  Kim, HoKwon; Mattevi, Cecilia; Kim, Hyun Jun; Mittal, Anudha; Mkhoyan, K. Andre; Riman, Richard E.; Chhowalla, Manish
  
  Nanoscale (2013), 5 (24), 12365-12374CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  Large area thin films of few-layered unfunctionalized graphene platelets are developed with fine control over the thickness. The thin films are obtained by a Langmuir-Blodgett assembly at the interface of graphene soln. in N-methyl-2-pyrrolidone (NMP) and water, and their optoelectronic properties and conduction mechanism are investigated in relation to lateral flake size and thin film thickness. The elec. cond. and carrier mobility are affected by the flake size (200 nm to 1 μm) and by the packing of the nanostructure platelet network. General effective medium theory is used to explain the thickness dependent cond. and to det. the percolation threshold film thickness which was found to be about 10 nm (at a vol. fraction of ∼39%) for a Langmuir-Blodgett film of an av. platelet lateral size of 170 ± 40 nm. The electronic behavior of the material shows more similarities with polycryst. turbostratic graphite than thin films of reduced graphene oxide, carbon nanotubes, or disordered conducting polymers. While in these systems the conduction mechanism is often dominated by the presence of an energy barrier between conductive and non-conductive regions in the network, in the exfoliated graphene networks the conduction mechanism can be explained by the simple two-band model which is characteristic of polycryst. graphite.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvVejurbI&md5=9775bedf8d82d1c5424deda2f8402183
353. 353
  Supur, M.; Ohkubo, K.; Fukuzumi, S. Photoinduced Charge Separation in Ordered Self-Assemblies of Perylenediimide-Graphene Oxide Hybrid Layers Chem. Commun. 2014, 50, 13359– 13361 DOI: 10.1039/C4CC05694A
  
  There is no corresponding record for this reference.
354. 354
  Dehsari, H. S.; Shalamzari, E. K.; Gavgani, J. N.; Taromi, F. A.; Ghanbary, S. Efficient Preparation of Ultralarge Graphene Oxide Using a PEDOT:PSS/GO Composite Layer as Hole Transport Layer in Polymer-Based Optoelectronic Devices RSC Adv. 2014, 4, 55067– 55076 DOI: 10.1039/C4RA09474C
  
  354
  Efficient preparation of ultralarge graphene oxide using a PEDOT:PSS/GO composite layer as hole transport layer in polymer-based optoelectronic devices
  
  Dehsari, Hamed Sharifi; Shalamzari, Elham Khodabakhshi; Gavgani, Jaber Nasrollah; Taromi, Faramarz Afshar; Ghanbary, Shima
  
  RSC Advances (2014), 4 (98), 55067-55076CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
  
  We herein report an investigation of ultralarge graphene oxide (UL-GO) sheet/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin composite layers fabricated by spin coating on an indium-tin-oxide (ITO) anode as hole transport layer (HTL) in polymer light-emitting diodes (PLEDs), as well as polymer solar cells (PSCs). Monolayer UL-GOs were first synthesized based on a novel soln.-phase method involving pre-exfoliation of graphite flakes which were then mixed into the PEDOT:PSS soln. in various specific amts. The PEDOT:PSS composite film mixed with 0.04 wt% UL-GO by wt. exhibits a cond. of 749.4 S cm-1 and a transmittance of 88.6% at 550 nm. The PEDOT:PSS/GO HTL shows enhanced charge carrier transport because of improved cond. by the weakening of the coulombic attraction between PEDOT and PSS by the functional groups on GO nanosheets, and the formation of an extended conductive network. Moreover, it can effectively block electrons and reduce resistance in the HTL, leading to better injection and transport of holes and lower turn-on voltage and resulting in a higher overall efficiency in PLEDs. Similarly, it remarkably increases the short circuit current (Jsc), and PSC efficiency because of a remarkable redn. of exciton quenching that results in higher charge extn. in PSCs. The optimized PLEDs and PSCs with a PEDOT:PSS/GO composite HTL layer show a max. luminosity of 725.6 cd m-2 (at 10.6 V) for PLEDs, as well as a power conversion efficiency of 3.388% for PSCs, which were improved by ∼11% and 12%, resp., compared to ref. PLEDs and PSCs with a PEDOT:PSS layer.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVWmu7fM&md5=a1dc1d1b44a0e052fa9dd958a6012aa6
355. 355
  Kymakis, E.; Savva, K.; Stylianakis, M. M.; Fotakis, C.; Stratakis, E. Flexible Organic Photovoltaic Cells with In Situ Nonthermal Photoreduction of Spin-Coated Graphene Oxide Electrodes Adv. Funct. Mater. 2013, 23, 2742– 2749 DOI: 10.1002/adfm.201202713
  
  355
  Flexible Organic Photovoltaic Cells with In Situ Nonthermal Photoreduction of Spin-Coated Graphene Oxide Electrodes
  
  Kymakis, Emmanuel; Savva, Kyriaki; Stylianakis, Minas M.; Fotakis, Costas; Stratakis, Emmanuel
  
  Advanced Functional Materials (2013), 23 (21), 2742-2749CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  The first redn. methodol., compatible with flexible, temp.-sensitive substrates, for the prodn. of reduced spin-coated graphene oxide (GO) electrodes is reported. It is based on the use of a laser beam for the in situ, non-thermal, redn. of spin-coated GO films on flexible substrates over a large area. The photoredn. process is one-step, facile, and is rapidly carried out at room temp. in air without affecting the integrity of the graphene lattice or the flexibility of the underlying substrate. Conductive graphene films with a sheet resistance of as low as 700 Ω sq-1 and transmittance of 44% can be obtained, much higher than can be achieved for flexible layers reduced by chem. means. As a proof of concept of the technique, laser-reduced GO (LrGO) films are utilized as transparent electrodes in flexible, bulk heterojunction, org. photovoltaic (OPV) devices, replacing the traditional ITO. The devices displayed a power-conversion efficiency of 1.1%, which is the highest reported so far for OPV device incorporating reduced GO as the transparent electrode. The in situ non-thermal photoredn. of spin-coated GO films creates a new way to produce flexible functional graphene electrodes for a variety of electronic applications in a process that carries substantial promise for industrial implementation.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXkvFCktw%253D%253D&md5=460633f56a0bb5b9f117153340e8820f
356. 356
  Oregan, B.; Gratzel, M. A Low-Cost, High-Efficiency Solar Cell Based on Dye-Sensitized Colloidal TiO₂ Films Nature 1991, 353, 737– 740 DOI: 10.1038/353737a0
  
  356
  A low-cost, high-efficiency solar cell based on dye-sensitized colloidal titanium dioxide films
  
  O'Regan, Brian; Graetzel, Michael
  
  Nature (London, United Kingdom) (1991), 353 (6346), 737-40CODEN: NATUAS; ISSN:0028-0836.
  
  A photoelectrochem. cell was fabricated from low- to medium-purity materials through low-cost processes, which exhibits a com. realistic energy-conversion efficiency. The device is based on a 10-μm-thick, optically transparent film of TiO2 particles, coated with a monolayer of a charge-transfer dye to sensitize the film for light harvesting. The device harvests a high proportion of the incident solar energy flux (46%) and shows exceptionally high efficiencies for the conversion of incident photons to elec. current (>80%). The overall light-to-elec. energy conversion yield is 7.1-8.9% in simulated solar light and 12% in diffuse daylight. The c.d. >12 mA/cm2 and exceptional stability (sustaining ≥5 million turnover without decompn.), and low cost, make practical applications feasible.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK38XoslOn&md5=02ea66126c0eea94a36e942139157b0f
357. 357
  Hagfeldt, A.; Boschloo, G.; Sun, L.; Kloo, L.; Pettersson, H. Dye-Sensitized Solar Cells Chem. Rev. 2010, 110, 6595– 6663 DOI: 10.1021/cr900356p
  
  357
  Dye-Sensitized Solar Cells
  
  Hagfeldt, Anders; Boschloo, Gerrit; Sun, Licheng; Kloo, Lars; Pettersson, Henrik
  
  Chemical Reviews (Washington, DC, United States) (2010), 110 (11), 6595-6663CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)
  
  A review on dye-sensitized solar cells (DSCs). Some brief notes on solar energy in general and DSC in particular are given, followed by a discussion of the operational principles of DSC (energetics and kinetics). Then, the development of material components and some specific exptl. techniques to characterize DSC are described. The current status of module development is also discussed, and finally a brief future outlook is given.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtFChs77M&md5=e6727377e1d3eec4c6c6d78276ff77a1
358. 358
  Cheng, G.; Akhtar, M. S.; Yang, O. B.; Stadler, F. J. Novel Preparation of Anatase TiO₂@Reduced Graphene Oxide Hybrids for High-Performance Dye-Sensitized Solar Cells ACS Appl. Mater. Interfaces 2013, 5, 6635– 6642 DOI: 10.1021/am4013374
  
  358
  Novel Preparation of Anatase TiO2@Reduced Graphene Oxide Hybrids for High-Performance Dye-Sensitized Solar Cells
  
  Cheng, Gang; Akhtar, M. Shaheer; Yang, O-Bong; Stadler, Florian J.
  
  ACS Applied Materials & Interfaces (2013), 5 (14), 6635-6642CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  An effective method was developed to prep. hybrid materials of TiO2 nanoparticles on reduced graphene oxide (RGO) sheets for application in solar cells. The morphol., size, and crystal phase of the TiO2 nanoparticles and TiO2@reduced graphene oxide (TiO2@RGO) hybrids were investigated in detail by X-ray diffraction (XRD), SEM, transmission electron microscopy (TEM), selected area electron diffraction (SAED), XPS, Raman, and UV-vis diffuse reflectance spectroscopy. A possible growth mechanism of TiO2@RGO hybrids is proposed based on observations of the TiO2 nanoparticles obtained from the hydrolysis process under different conditions. The effects of different reduced graphene oxide contents on the energy conversion efficiency of the dye-sensitized solar cells (DSSCs) based on J-V and incident photon-to-current conversion efficiency (IPCE) spectra are also discussed. DSSCs based on TiO2@RGO hybrid photoanodes with a graphene content of 1.6 wt % showed an overall light-to-electricity conversion efficiency of 7.68%, which is much higher than that of pure anatase nanoparticles (4.78%) accompanied by a short-circuit c.d. of 18.39 mA cm2, an open-circuit voltage of 0.682 V, and a fill factor of 61.2%.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXpsFGktbw%253D&md5=856f37f5b06005fe85bb5e283a63a5e2
359. 359
  Bi, E.; Chen, H.; Yang, X.; Peng, W.; Graetzel, M.; Han, L. A Quasi Core-Shell Nitrogen-Doped Graphene/Cobalt Sulfide Conductive Catalyst for Highly Efficient Dye-Sensitized Solar Cells Energy Environ. Sci. 2014, 7, 2637– 2641 DOI: 10.1039/C4EE01339E
  
  There is no corresponding record for this reference.
360. 360
  Yang, W. S.; Noh, J. H.; Jeon, N. J.; Kim, Y. C.; Ryu, S.; Seo, J.; Seok, S. I. High-Performance Photovoltaic Perovskite Layers Fabricated through Intramolecular Exchange Science 2015, 348, 1234– 1237 DOI: 10.1126/science.aaa9272
  
  360
  High-performance photovoltaic perovskite layers fabricated through intramolecular exchange
  
  Yang, Woon Seok; Noh, Jun Hong; Jeon, Nam Joong; Kim, Young Chan; Ryu, Seungchan; Seo, Jangwon; Seok, Sang Il
  
  Science (Washington, DC, United States) (2015), 348 (6240), 1234-1237CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  The band gap of formamidinium lead iodide (FAPbI3) perovskites allows broader absorption of the solar spectrum relative to conventional methylammonium lead iodide (MAPbI3). Because the optoelectronic properties of perovskite films are closely related to film quality, deposition of dense and uniform films is crucial for fabricating high-performance perovskite solar cells (PSCs). An approach is reported for depositing high-quality FAPbI3 films, involving FAPbI3 crystn. by the direct intramol. exchange of dimethylsulfoxide (DMSO) mols. intercalated in PbI2 with formamidinium iodide. This process produces FAPbI3 films with (111)-preferred crystallog. orientation, large-grained dense microstructures, and flat surfaces without residual PbI2. Using films prepd. by this technique, the FAPbI3-based PSCs are fabricated with max. power conversion efficiency greater than 20%.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXps1OltL0%253D&md5=f3f3e002b2ff01a20b09eb6cab4cc0c5
361. 361
  Jeon, N. J.; Noh, J. H.; Yang, W. S.; Kim, Y. C.; Ryu, S.; Seo, J.; Seok, S. I. Compositional Engineering of Perovskite Materials for High-Performance Solar Cells Nature 2015, 517, 476– 480 DOI: 10.1038/nature14133
  
  361
  Compositional engineering of perovskite materials for high-performance solar cells
  
  Jeon, Nam Joong; Noh, Jun Hong; Yang, Woon Seok; Kim, Young Chan; Ryu, Seungchan; Seo, Jangwon; Seok, Sang Il
  
  Nature (London, United Kingdom) (2015), 517 (7535), 476-480CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)
  
  Here we combine the promising, owing to its comparatively narrow bandgap, but relatively unstable formamidinium lead iodide (FAPbI3) with methylammonium lead bromide (MAPbBr3) as the light-harvesting unit in a bilayer solar cell architecture. We investigated phase stability, morphol. of the perovskite layer, hysteresis in current-voltage characteristics, and overall performance as a function of chem. compn. Our results show that incorporation of MAPbBr3 into FAPbI3 stabilizes the perovskite phase of FAPbI3 and improves the power conversion efficiency of the solar cell to >18% under a std. illumination of 100 mW/cm2. These findings further emphasize the versatility and performance potential of inorg.-org. lead halide perovskite materials for photovoltaic applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXivF2msg%253D%253D&md5=6b63487cbd6ca18ba27638ae8887c711
362. 362
  Kong, D.; Wang, H.; Cha, J. J.; Pasta, M.; Koski, K. J.; Yao, J.; Cui, Y. Synthesis of MoS₂ and MoSe₂ Films with Vertically Aligned Layers Nano Lett. 2013, 13, 1341– 1347 DOI: 10.1021/nl400258t
  
  362
  Synthesis of MoS2 and MoSe2 Films with Vertically Aligned Layers
  
  Kong, Desheng; Wang, Haotian; Cha, Judy J.; Pasta, Mauro; Koski, Kristie J.; Yao, Jie; Cui, Yi
  
  Nano Letters (2013), 13 (3), 1341-1347CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Layered materials consist of mol. layers stacked together by weak interlayer interactions. They often crystallize to form atomically smooth thin films, nanotubes, and platelet or fullerene-like nanoparticles due to the anisotropic bonding. Structures that predominately expose edges of the layers exhibit high surface energy and are often considered unstable. The authors present a synthesis process to grow MoS2 and MoSe2 thin films with vertically aligned layers, thereby maximally exposing the edges on the film surface. Such edge-terminated films are metastable structures of MoS2 and MoSe2, which may find applications in diverse catalytic reactions. The authors confirmed their catalytic activity in a hydrogen evolution reaction (HER), in which the exchange c.d. correlates directly with the d. of the exposed edge sites.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXitFajsLY%253D&md5=12750e01fd7cb5c14b79f2c6168d02b0
363. 363
  Wang, H.; Kong, D.; Johanes, P.; Cha, J. J.; Zheng, G.; Yan, K.; Liu, N.; Cui, Y. MoSe₂ and WSe₂ Nanofilms with Vertically Aligned Molecular Layers on Curved and Rough Surfaces Nano Lett. 2013, 13, 3426– 3433 DOI: 10.1021/nl401944f
  
  363
  MoSe2 and WSe2 Nanofilms with Vertically Aligned Molecular Layers on Curved and Rough Surfaces
  
  Wang, Haotian; Kong, Desheng; Johanes, Petr; Cha, Judy J.; Zheng, Guangyuan; Yan, Kai; Liu, Nian; Cui, Yi
  
  Nano Letters (2013), 13 (7), 3426-3433CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  Two-dimensional (2D) layered materials exhibit high anisotropy in material properties due to the large difference of intra- and interlayer bonding. This presents opportunities to engineer materials whose properties strongly depend on the orientation of the layers relative to the substrate. Using a similar growth process reported in their previous study of MoS2 and MoSe2 films whose layers were oriented vertically on flat substrates, the authors demonstrate that the vertical layer orientation can be realized on curved and rough surfaces such as nanowires (NWs) and microfibers. Such structures can increase the surface area while maintaining the perpendicular orientation of the layers, which may be useful in enhancing various catalytic activities. Vertically aligned MoSe2 and WSe2 nanofilms on Si NWs and carbon fiber paper are presented. The MoSe2 and WSe2 nanofilms on carbon fiber paper are highly efficient electrocatalysts for hydrogen evolution reaction (HER) compared with flat substrates. Both materials exhibit extremely high stability in acidic soln. as the HER catalytic activity shows no degrdn. after 15,000 continuous potential cycles. The HER activity of MoSe2 is further improved by Ni doping.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtVWhurfE&md5=25f2bdf006d4556ce0f93f0df121cf8c
364. 364
  Chen, W. F.; Wang, C. H.; Sasaki, K.; Marinkovic, N.; Xu, W.; Muckerman, J. T.; Zhu, Y.; Adzic, R. R. Highly Active and Durable Nanostructured Molybdenum Carbide Electrocatalysts for Hydrogen Production Energy Environ. Sci. 2013, 6, 943– 951 DOI: 10.1039/c2ee23891h
  
  364
  Highly active and durable nanostructured molybdenum carbide electrocatalysts for hydrogen production
  
  Chen, W.-F.; Wang, C.-H.; Sasaki, K.; Marinkovic, N.; Xu, W.; Muckerman, J. T.; Zhu, Y.; Adzic, R. R.
  
  Energy & Environmental Science (2013), 6 (3), 943-951CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)
  
  In an attempt to tailor low-cost, precious-metal-free electrocatalysts for water electrolysis in acid, molybdenum carbide (β-Mo2C) nanoparticles are prepd. by in situ carburization of ammonium molybdate on carbon nanotubes and XC-72R carbon black without using any gaseous carbon source. The formation of Mo2C is investigated by thermogravimetry and in situ X-ray diffraction. X-ray absorption anal. reveals that Mo2C nanoparticles are inlaid or anchored into the carbon supports, and the electronic modification makes the surface exhibit a relatively moderate Mo-H bond strength. It is found that carbon nanotube-supported Mo2C showed superior electrocatalytic activity and stability in the hydrogen evolution reaction (HER) compared to the bulk Mo2C. An overpotential of 63 mV for driving 1 mA cm-2 of c.d. was measured for the nanotube-supported Mo2C catalysts; this exceeds the activity of analogous Mo2C catalysts. The enhanced electrochem. activity is facilitated by unique effects of the anchored structure coupled with the electronic modification.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXivVGktro%253D&md5=99a1c039221fb31d192a4a35a70eeff3
365. 365
  Vrubel, H.; Hu, X. Molybdenum Boride and Carbide Catalyze Hydrogen Evolution in both Acidic and Basic Solutions Angew. Chem., Int. Ed. 2012, 51, 12703– 12706 DOI: 10.1002/anie.201207111
  
  365
  Molybdenum Boride and Carbide Catalyze Hydrogen Evolution in both Acidic and Basic Solutions
  
  Vrubel, Heron; Hu, Xile
  
  Angewandte Chemie, International Edition (2012), 51 (51), 12703-12706CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  MoB and Mo2C particles are excellent catalysts for hydrogen evolution in acidic and basic solns. The catalysts are stable during an electrolysis with exemption of MoB at pH 14. The activity in alk. solns. is surprising high and is comparable to that in acidic solns. The molybdenum boride and carbide were pressed onto a soft carbon paste electrodes with reasonably high loading. The possible reaction mechanism of hydrogen formation is briefly discussed.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1GgsrbN&md5=e7481bc3202e36d6c6eaf7a06daeab2f
366. 366
  Karunadasa, H. I.; Montalvo, E.; Sun, Y.; Majda, M.; Long, J. R.; Chang, C. J. A Molecular MoS₂ Edge Site Mimic for Catalytic Hydrogen Generation Science 2012, 335, 698– 702 DOI: 10.1126/science.1215868
  
  366
  A Molecular MoS2 Edge Site Mimic for Catalytic Hydrogen Generation
  
  Karunadasa, Hemamala I.; Montalvo, Elizabeth; Sun, Yujie; Majda, Marcin; Long, Jeffrey R.; Chang, Christopher J.
  
  Science (Washington, DC, United States) (2012), 335 (6069), 698-702CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  Inorg. solids are an important class of catalysts that often derive their activity from sparse active sites that are structurally distinct from the inactive bulk. Rationally optimizing activity is therefore beholden to the challenges in studying these active sites in mol. detail. Here, we report a mol. that mimics the structure of the proposed triangular active edge site fragments of molybdenum disulfide (MoS2), a widely used industrial catalyst that has shown promise as a low-cost alternative to platinum for electrocatalytic hydrogen prodn. By leveraging the robust coordination environment of a pentapyridyl ligand, we synthesized and structurally characterized a well-defined MoIV-disulfide complex that, upon electrochem. redn., can catalytically generate hydrogen from acidic org. media as well as from acidic water.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhvVCjsr8%253D&md5=66849a25acaecaf60e1922de5397b061
367. 367
  Chen, W.-F.; Sasaki, K.; Ma, C.; Frenkel, A. I.; Marinkovic, N.; Muckerman, J. T.; Zhu, Y.; Adzic, R. R. Hydrogen-Evolution Catalysts Based on Non-Noble Metal Nickel-Molybdenum Nitride Nanosheets Angew. Chem., Int. Ed. 2012, 51, 6131– 6135 DOI: 10.1002/anie.201200699
  
  367
  Hydrogen-Evolution Catalysts Based on Non-Nobel Metal Nickel-Molybdenum Nitride Nanosheets
  
  Chen, Wei-Fu; Sasaki, Kotaro; Ma, Chao; Frenkel, Anatoly I.; Marinkovic, Nebojsa; Muckerman, James T.; Zhu, Yimei; Adzic, Radoslav R.
  
  Angewandte Chemie, International Edition (2012), 51 (25), 6131-6135, S6131/1-S6131/12CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  The heterogeneous electrocatalytic hydrogen-evolving system was created from earth-abundant and inexpensive components. The NiMoNx/C catalyst exhibited an excellent activity for the HER with a small overpotential of 78 mV, a high exchange current and a Tafel slope as small as 35 mVdec-1. In acidic solns. the catalyst can be used without noticeable corrosion. The XANES results provided an approach to understand electronic properties and the stabilizing effect on nitrogen on metallic states of nickel and molybdenum.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xms1ekt7Y%253D&md5=fc19864cc8d06336216a1d8acfb15008
368. 368
  Cao, B.; Veith, G. M.; Neuefeind, J. C.; Adzic, R. R.; Khalifah, P. G. Mixed Close-Packed Cobalt Molybdenum Nitrides as Non-noble Metal Electrocatalysts for the Hydrogen Evolution Reaction J. Am. Chem. Soc. 2013, 135, 19186– 19192 DOI: 10.1021/ja4081056
  
  368
  Mixed Close-Packed Cobalt Molybdenum Nitrides as Non-noble Metal Electrocatalysts for the Hydrogen Evolution Reaction
  
  Cao, Bingfei; Veith, Gabriel M.; Neuefeind, Joerg C.; Adzic, Radoslav R.; Khalifah, Peter G.
  
  Journal of the American Chemical Society (2013), 135 (51), 19186-19192CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  A two-step solid-state reaction for prepg. cobalt molybdenum nitride with a nanoscale morphol. was used to produce a highly active and stable electrocatalyst for the hydrogen evolution reaction (HER) under acidic conditions that achieves an iR-cor. c.d. of 10 mA cm-2 at -0.20 V vs RHE at low catalyst loadings of 0.24 mg/cm2 in rotating disk expts. under a H2 atmosphere. Neutron powder diffraction and pair distribution function (PDF) studies were used to overcome the insensitivity of x-ray diffraction data to different transition-metal nitride structural polytypes and show that this cobalt molybdenum nitride crystallizes in space group P63/mmc with lattice parameters of a = 2.85176(2) Å and c = 10.9862(3) Å and a formula of Co0.6Mo1.4N2. This space group results from the four-layered stacking sequence of a mixed close-packed structure with alternating layers of transition metals in octahedral and trigonal prismatic coordination and is a structure type for which HER activity has not previously been reported. Based on the accurate bond distances obtained from time-of-flight neutron diffraction data, the octahedral sites contain a mixt. of divalent Co and trivalent Mo, while the trigonal prismatic sites contain Mo in a higher oxidn. state. XPS studies confirm that at the sample surface nitrogen is present and N-H moieties are abundant.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslSqtLnO&md5=b65e53cfc94b1ff7a0d01e92312332b6
369. 369
  Chen, W.-F.; Iyer, S.; Iyer, S.; Sasaki, K.; Wang, C.-H.; Zhu, Y.; Muckerman, J. T.; Fujita, E. Biomass-Derived Electrocatalytic Composites for Hydrogen Evolution Energy Environ. Sci. 2013, 6, 1818– 1826 DOI: 10.1039/c3ee40596f
  
  369
  Biomass-derived electrocatalytic composites for hydrogen evolution
  
  Chen, Wei-Fu; Iyer, Shilpa; Iyer, Shweta; Sasaki, Kotaro; Wang, Chiu-Hui; Zhu, Yimei; Muckerman, James T.; Fujita, Etsuko
  
  Energy & Environmental Science (2013), 6 (6), 1818-1826CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)
  
  The prodn. of hydrogen from water electrolysis calls for an efficient non-precious-metal catalyst to make the process economically viable because of the high cost and the limited supply of the currently used platinum catalysts. Here we present such a catalyst made from earth-abundant molybdenum and common, humble soybeans (MoSoy). This catalyst, composed of a catalytic β-Mo2C phase and an acid-proof γ-Mo2N phase, drives the hydrogen evolution reaction (HER) with low overpotentials, and is highly durable in a corrosive acidic soln. over a period exceeding 500 h. When supported on graphene sheets, the MoSoy catalyst exhibits very fast charge transfer kinetics, and its performance rivals that of noble-metal catalysts such as Pt for hydrogen prodn. These findings prove that the soybean (as well as other high-protein biomass) is a useful material for the generation of catalysts incorporating an abundant transition metal, thereby challenging the exclusivity of platinum catalysts in the hydrogen economy.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXnvFyrs70%253D&md5=763844fc6718752f126e4d00875d3965
370. 370
  Xie, X.; Lin, L.; Liu, R.-Y.; Jiang, Y.-F.; Zhu, Q.; Xu, A.-W. The Synergistic Effect of Metallic Molybdenum Dioxide Nanoparticle Decorated Graphene as an Active Electrocatalyst for an Enhanced Hydrogen Evolution Reaction J. Mater. Chem. A 2015, 3, 8055– 8061 DOI: 10.1039/C5TA00622H
  
  370
  The synergistic effect of metallic molybdenum dioxide nanoparticle decorated graphene as an active electrocatalyst for an enhanced hydrogen evolution reaction
  
  Xie, Xiao; Lin, Ling; Liu, Rui-Yang; Jiang, Yi-Fan; Zhu, Qing; Xu, An-Wu
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (15), 8055-8061CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  As a durable and renewable fuel, H has attracted a huge amt. of global interest in its prodn. via different routes. Among these methods, the electrocatalytic H evolution reaction (HER) is one of the most promising ways for low-cost H prodn. in the future. A simple redox hydrothermal method was developed to fabricate a noble-metal-free MoO2/rGO composite for a highly efficient HER. GO nanosheets provide O-contg. functional groups for precursor attachment, and restrict growth of MoO2 nanoparticles (NPs) with a small size due to the space confinement effect among GO layers as well. Benefitting from a synergistic effect between metallic MoO2 NPs and graphene, the obtained MoO2/rGO composite exhibits excellent HER activity with a small onset overpotential of 190 mV, a large cathodic c.d., and a small Tafel slope of 49 mV per decade, while MoO2 NPs or rGO itself is not a very efficient HER catalyst. Addnl., the MoO2/rGO composite displays good stability after 1000 potential cycles under both acidic and alk. conditions. Dramatically improved HER activity and excellent stability are attributed to small size, more active sites, high cond. and a synergistic effect of MoO2 NPs and graphene. The development of the MoO2/rGO composite as an enhanced active HER catalyst broadens the members of Mo-based HER catalysts and provides an insight into the design and synthesis of other noble-metal-free materials for the cost-effective and environmentally friendly catalyst in electrochem. H prodn.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXks1aqt7k%253D&md5=94ee1d6c590571fb84bdfc19b94d5fe6
371. 371
  Chang, Y.-H.; Lin, C.-T.; Chen, T.-Y.; Hsu, C.-L.; Lee, Y.-H.; Zhang, W.; Wei, K.-H.; Li, L.-J. Highly Efficient Electrocatalytic Hydrogen Production by MoS_x Grown on Graphene-Protected 3D Ni Foams Adv. Mater. 2013, 25, 756– 760 DOI: 10.1002/adma.201202920
  
  371
  Highly Efficient Electrocatalytic Hydrogen Production by MoSx Grown on Graphene-Protected 3D Ni Foams
  
  Chang, Yung-Huang; Lin, Cheng-Te; Chen, Tzu-Yin; Hsu, Chang-Lung; Lee, Yi-Hsien; Zhang, Wenjing; Wei, Kung-Hwa; Li, Lain-Jong
  
  Advanced Materials (Weinheim, Germany) (2013), 25 (5), 756-760CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Hydrogen energy is clean and serves as one of the most promising candidates for replacing petroleum fuels in the future. Although the rare metals, such as platinum, have high efficiency in the hydrogen evolution reaction (HER), their scarcity and high cost inhibit large scale applications. To improve the electrocatalytic HER efficiency, it is crucial to effectively increase the surface area for catalyst loading. Hence, the research into three-dimensional (3D) electrode structures is emergent. A three-dimensional graphene foam synthesized on the Ni foam skeleton by chem. vapor deposition (CVD) has been reported. The graphene foam without the support of an Ni skeleton is brittle and is not able to serve as a 3D electrode for hosting catalysts. The 3D Ni foam is a low cost and conductive metal with a high surface area, which is ideal for use as a template to host catalysts for increasing the no. of reaction sites. However, it suffers from instability in acidic solns., and thus is not suitable for the electrocatalytic HER.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsFSntL%252FM&md5=1d3a218d9edc0aaec47ee611e22556bc
372. 372
  Levy, R. B.; Boudart, M. Platinum-Like Behavior of Tungsten Carbide in Surface Catalysis Science 1973, 181, 547– 549 DOI: 10.1126/science.181.4099.547
  
  372
  Platinum-like behavior of tungsten carbide in surface catalysis
  
  Levy, R. B.; Boudart, M.
  
  Science (Washington, DC, United States) (1973), 181 (4099), 547-9CODEN: SCIEAS; ISSN:0036-8075.
  
  WC catalyzes the formation of H2O from H and O at room temp., the redn. of WO3 by H in the presence of H2O, and the isomerization of Me4C to isopentane. This catalytic behavior, which is typical of Pt, is not exhibited at all by W. The surface electronic properties of the latter are therefore modified by C in such a way that they resemble those of Pt.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaE3sXkvVerurs%253D&md5=261e2de904e1c708715cbe8916279310
373. 373
  Pan, L. F.; Li, Y. H.; Yang, S.; Liu, P. F.; Yu, M. Q.; Yang, H. G. Molybdenum Carbide Stabilized on Graphene with High Electrocatalytic Activity for Hydrogen Evolution Reaction Chem. Commun. 2014, 50, 13135– 13137 DOI: 10.1039/C4CC05698A
  
  373
  Molybdenum carbide stabilized on graphene with high electrocatalytic activity for hydrogen evolution reaction
  
  Pan, Lin Feng; Li, Yu Hang; Yang, Shuang; Liu, Peng Fei; Yu, Ming Quan; Yang, Hua Gui
  
  Chemical Communications (Cambridge, United Kingdom) (2014), 50 (86), 13135-13137CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)
  
  The authors developed a general two-step method to prep. Mo carbide (Mo2C) nanoparticles stabilized by a C layer on reduced graphene oxide (RGO) sheets. The Mo2C-RGO hybrid showed excellent performance, which is attributed to the intimate interactions between Mo2C and graphene as well as the outer protection of the C layer.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVyhtr%252FF&md5=e2b598c990cf4f7812171b9fb96414dc
374. 374
  Zhang, X.; Meng, F.; Mao, S.; Ding, Q.; Shearer, M. J.; Faber, M. S.; Chen, J.; Hamers, R. J.; Jin, S. Amorphous MoS_xCl_y Electrocatalyst Supported by Vertical Graphene for Efficient Electrochemical and Photoelectrochemical Hydrogen Generation Energy Environ. Sci. 2015, 8, 862– 868 DOI: 10.1039/C4EE03240C
  
  374
  Amorphous MoSxCly electrocatalyst supported by vertical graphene for efficient electrochemical and photoelectrochemical hydrogen generation
  
  Zhang, Xingwang; Meng, Fei; Mao, Shun; Ding, Qi; Shearer, Melinda J.; Faber, Matthew S.; Chen, Junhong; Hamers, Robert J.; Jin, Song
  
  Energy & Environmental Science (2015), 8 (3), 862-868CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)
  
  We report amorphous MoSxCly as a high-performance electrocatalyst for both electrochem. and photoelectrochem. hydrogen generation. This novel ternary electrocatalyst is synthesized via chem. vapor deposition at temps. lower than those typically used to grow cryst. MoS2 nanostructures and structurally characterized. The MoSxCly electrocatalysts exhibit stable and high catalytic activity toward the hydrogen evolution reaction, as evidenced by large cathodic current densities at low overpotentials and low Tafel slopes (ca. 50 mV decade-1). The electrocatalytic performance can be further enhanced through depositing MoSxCly on conducting vertical graphenes. Furthermore, MoSxCly can be directly deposited on p-type silicon photocathodes to enable efficient photoelectrochem. hydrogen evolution.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXkslCquw%253D%253D&md5=3232dc40b1fdf8ad89b8df054f77e380
375. 375
  Zhou, W.; Zhou, J.; Zhou, Y.; Lu, J.; Zhou, K.; Yang, L.; Tang, Z.; Li, L.; Chen, S. N-Doped Carbon-Wrapped Cobalt Nanoparticles on N-Doped Graphene Nanosheets for High-Efficiency Hydrogen Production Chem. Mater. 2015, 27, 2026– 2032 DOI: 10.1021/acs.chemmater.5b00331
  
  375
  N-Doped Carbon-Wrapped Cobalt Nanoparticles on N-Doped Graphene Nanosheets for High-Efficiency Hydrogen Production
  
  Zhou, Weijia; Zhou, Jian; Zhou, Yucheng; Lu, Jia; Zhou, Kai; Yang, Linjing; Tang, Zhenghua; Li, Ligui; Chen, Shaowei
  
  Chemistry of Materials (2015), 27 (6), 2026-2032CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)
  
  Development of non-noble metal catalysts for H evolution reaction (HER) with both excellent activity and robust stability has remained a key challenge in the past decades. Herein, for the 1st time, N-doped C-wrapped Co nanoparticles supported on N-doped graphene nanosheets were prepd. by a facile solvothermal procedure and subsequent calcination at controlled temps. The electrocatalytic activity for HER was examd. in 0.5M H2SO4. Electrochem. measurements showed a small overpotential of only -49 mV with a Tafel slope of 79.3 mV/dec. Theor. calcns. based on d. functional theory showed that the catalytically active sites were due to C atoms promoted by the entrapped Co nanoparticles. The results may offer a new methodol. for the prepn. of effective catalysts for H2O splitting technol.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjvVOhtL0%253D&md5=55f338f1b102d48542cef352aacb8e78
376. 376
  Chowdhury, I.; Duch, M. C.; Mansukhani, N. D.; Hersam, M. C.; Bouchard, D. Colloidal Properties and Stability of Graphene Oxide Nanomaterials in the Aquatic Environment Environ. Sci. Technol. 2013, 47, 6288– 6296 DOI: 10.1021/es400483k
  
  376
  Colloidal Properties and Stability of Graphene Oxide Nanomaterials in the Aquatic Environment
  
  Chowdhury, Indranil; Duch, Matthew C.; Mansukhani, Nikhita D.; Hersam, Mark C.; Bouchard, Dermont
  
  Environmental Science & Technology (2013), 47 (12), 6288-6296CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
  
  While graphene oxide (GO) has been found the most toxic graphene-based nanomaterial, its environmental fate is still unexplored. The aggregation kinetics and stability of GO were studied using time-resolved dynamic light scattering over a wide range of aquatic chemistries (pH, salt types (NaCl, MgCl2, CaCl2), ionic strength) relevant to natural and engineered systems. Although pH did not have a notable effect on GO stability from pH 4 to 10, salt type and ionic strength had significant effects on GO stability due to elec. double layer compression, similar to other colloidal particles. The crit. coagulation concn. (CCC) values of GO were detd. to be 44mM NaCl, 0.9mM CaCl2, and 1.3mM MgCl2. Aggregation and stability of GO in the aquatic environment followed colloidal theory (DLVO and Schulze-Hardy rule), even though GO's shape is not spherical. CCC values of GO were lower than reported fullerene CCC values and higher than reported C nanotube CCC values. CaCl2 destabilized GO more aggressively than MgCl2 and NaCl due to the binding capacity of Ca2+ with hydroxyl and carbonyl functional groups of GO. Natural org. matter significantly improved the stability of GO in water primarily due to steric repulsion. Long-term stability studies demonstrated that GO was highly stable in both natural and synthetic surface waters, although it settled quickly in synthetic groundwater. While GO remained stable in synthetic influent wastewater, effluent wastewater collected from a treatment plant rapidly destabilized GO, indicating GO will settle out during the wastewater treatment process and likely accumulate in biosolids and sludge. Overall, our findings indicate that GO nanomaterials will be stable in the natural aquatic environment and that significant aq. transport of GO is possible.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXnsFSiurs%253D&md5=74130013e227ff8e136217141f99f6fc
377. 377
  Achari, A.; Datta, K. K. R.; De, M.; Dravid, V. P.; Eswaramoorthy, M. Amphiphilic Aminoclay-RGO Hybrids: ASimple Strategy to Disperse a High Concentration of RGO in Water Nanoscale 2013, 5, 5316– 5320 DOI: 10.1039/c3nr01108a
  
  There is no corresponding record for this reference.
378. 378
  McCoy, T. M.; Brown, P.; Eastoe, J.; Tabor, R. F. Noncovalent Magnetic Control and Reversible Recovery of Graphene Oxide Using Iron Oxide and Magnetic Surfactants ACS Appl. Mater. Interfaces 2015, 7, 2124– 2133 DOI: 10.1021/am508565d
  
  378
  Noncovalent Magnetic Control and Reversible Recovery of Graphene Oxide Using Iron Oxide and Magnetic Surfactants
  
  McCoy, Thomas M.; Brown, Paul; Eastoe, Julian; Tabor, Rico F.
  
  ACS Applied Materials & Interfaces (2015), 7 (3), 2124-2133CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  The unique charging properties of graphene oxide (GO) are exploited in the prepn. of a range of noncovalent magnetic GO materials, using microparticles, nanoparticles, and magnetic surfactants. Adsorption and desorption were controlled by modification of pH within a narrow window of <2 pH units. The benefit conferred by using charge-based adsorption is that the process is reversible, and the GO can be captured and sepd. from the magnetic nanomaterial, such that both components can be recycled. Iron oxide (Fe2O3) microparticles form a loosely flocculated gel network with GO, which is demonstrated to undergo magnetic compressional dewatering in the presence of an external magnetic field. For composites formed from GO and Fe2O3 nanoparticles, it is found that low Fe2O3:GO mass ratios ( < 5:1) favor flocculation of GO, whereas higher ratios ( > 5:1) cause overcharging of the surfaces resulting in restabilization. The effectiveness of the GO adsorption and magnetic capture process is demonstrated by sepg. traditionally difficult-to-recover gold nanoparticles (d ≈ 10 nm) from water. The fully recyclable nature of the assembly and capture process, combined with the vast adsorption capacity of GO, presents obvious and appealing advantages for applications in decontamination and water treatment.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhslCmtQ%253D%253D&md5=741eb062a94cc3ed2ee3bd5c9c32dbab
379. 379
  Le, N. H.; Seema, H.; Kemp, K. C.; Ahmed, N.; Tiwari, J. N.; Park, S.; Kim, K. S. Solution-Processable Conductive Micro-Hydrogels of Nanoparticle/Graphene Platelets Produced by Reversible Self-Assembly and Aqueous Exfoliation J. Mater. Chem. A 2013, 1, 12900– 12908 DOI: 10.1039/c3ta12735d
  
  379
  Solution-processable conductive micro-hydrogels of nanoparticle/graphene platelets produced by reversible self-assembly and aqueous exfoliation
  
  Le, Nhien H.; Seema, Humaira; Kemp, K. Christian; Ahmed, Nisar; Tiwari, Jitendra N.; Park, Sungjin; Kim, Kwang S.
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2013), 1 (41), 12900-12908CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Preventing the π-π restacking of graphene-based platelets is essential to advance their fundamental attributes in a wide range of scalable chem. processes. Using macroscopic hydrogels of H2O-intercalated metal-oxide/graphene platelets is a novel approach to produce microscopic hydrogels with extraordinary surface accessibility and electronic properties. Nanoparticle decoration and surface hydration prevent irreversible π-π stacking, paving the way for reversible self-assembly and aq.-phase exfoliation. The hydrophilic nanoparticle coating facilitates the colloidal stability of hybrid microgels in aq. and org. media without the assistance of surfactants. This allows these materials to versatilely function as basic building blocks as well as applied nanomaterials in wet-chem. applications. The preservation of unique properties of SnO2-decorated graphene platelets leads to significantly enhanced adsorptive and photocatalytic activities. By exploiting the fluorescence quenching effect, a dye-hydrogel complex can be used as a supramol. sensor for sensitive DNA detection. This study also initiates an innovative synthetic strategy to synthesize high-quality graphene-based nanomaterials.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFGgtL7P&md5=fd10db86672bd8f6ffb3ce0c4ce87763
380. 380
  Zubir, N. A.; Yacou, C.; Motuzas, J.; Zhang, X.; da Costa, J. C. D. Structural and Functional Investigation of Graphene Oxide-Fe₃O₄ Nanocomposites for the Heterogeneous Fenton-Like Reaction Sci. Rep. 2014, 4, 4594 DOI: 10.1038/srep04594
  
  380
  Structural and functional investigation of graphene oxide-Fe3O4 nanocomposites for the heterogeneous Fenton-like reaction
  
  Zubir, Nor Aida; Yacou, Christelle; Motuzas, Julius; Zhang, Xiwang; Diniz da Costa, Joao C.
  
  Scientific Reports (2014), 4 (), article 4594CODEN: SRCEC3; ISSN:2045-2322. (Nature Publishing Group)
  
  Graphene oxide-iron oxide (GO-Fe3O4) nanocomposites were synthesized by co-pptg. iron salts onto GO sheets in basic soln. The results showed that formation of two distinct structures was dependent upon the GO loading. The first structure corresponds to a low GO loading up to 10 wt%, assocd. with the beneficial intercalation of GO within (Fe3O4) nanoparticles and resulting in higher surface area up to 409 m[sup: null] g[sup: null]. High GO loading beyond 10 wt% led to the aggregation of Fe[sub: null]O[sub: null] nanoparticles and the undesirable stacking of GO sheets. The presence of strong interfacial interactions (Fe-O-C bonds) between both components at low GO loading lead to 20% higher degrdn. of Acid Orange 7 than the Fe3O4 nanoparticles in heterogeneous Fenton-like reaction. This behavior was attributed to synergistic structural and functional effect of the combined GO and Fe3O4 nanoparticles.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXptVyju7c%253D&md5=d3cb4a30101eb814cc39063fc4d09248
381. 381
  Liu, Y.; Jiang, X.; Li, B.; Zhang, X.; Liu, T.; Yan, X.; Ding, J.; Cai, Q.; Zhang, J. Halloysite Nanotubes@Reduced Graphene Oxide Composite for Removal of Dyes from Water and as Supercapacitors J. Mater. Chem. A 2014, 2, 4264– 4269 DOI: 10.1039/c3ta14594h
  
  381
  Halloysite nanotubes@reduced graphene oxide composite for removal of dyes from water and as supercapacitors
  
  Liu, Yushan; Jiang, Xiaoqing; Li, Baojun; Zhang, Xudong; Liu, Tiezhu; Yan, Xiaoshe; Ding, Jie; Cai, Qiang; Zhang, Jianmin
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (12), 4264-4269CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Halloysite nanotubes (HNTs) were dispersed and loaded homogeneously onto the surface of reduced graphene oxide (rGO) sheets via an electrostatic self-assembly process. The selective modification of the outmost surface with γ-aminopropyl triethoxysilane (APTES) was performed. The outmost surface of the APTES-HNTs (APHNTs) was converted into a pos. charged surface under acidic conditions due to the existence of amine-tailed short org. chains. A combination then occurred driven by the electrostatic force between the neg. GO sheets and pos. APHNTs. A HNTs@rGO composite (HGC) was fabricated after redn. of GO and investigated as an adsorbent and electrode material. The superior behavior of HGC for rhodamine B (RhB) removal and high performance as a supercapacitor highlight the potential applications of HGC in waste water treatment and energy storage issues.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjt12ru7w%253D&md5=b0a281727b1b69d2a4ce92abd143e757
382. 382
  Dong, Z.; Wang, D.; Liu, X.; Pei, X.; Chen, L.; Jin, J. Bio-Inspired Surface-Functionalization of Graphene Oxide for the Adsorption of Organic Dyes and Heavy Metal Ions with a Superhigh Capacity J. Mater. Chem. A 2014, 2, 5034– 5040 DOI: 10.1039/c3ta14751g
  
  382
  Bio-inspired surface-functionalization of graphene oxide for the adsorption of organic dyes and heavy metal ions with a superhigh capacity
  
  Dong, Zhihui; Wang, Dong; Liu, Xia; Pei, Xianfeng; Chen, Liwei; Jin, Jian
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2014), 2 (14), 5034-5040CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  By utilizing the synergistic effect of poly-dopamine (PD) with functional groups and graphene oxide (GO) with a high surface area, a series of sub-nano thick PD layer coated GO (PD/GO) composites were fabricated by a well-controlled self-polymn. of dopamine via catechol chem. and used for effectively decontaminating wastewater. The obtained PD/GO could selectively adsorb the dyes contg. an Eschenmoser structure and showed an extremely high adsorption capacity up to 2.1 g/g, which represents the highest value among dye adsorptions reported so far. The adsorption mechanism was investigated by FTIR anal., soln. pH effect, and some control expts. It was concluded that the adsorption process was based on the Eschenmoser salt assisted 1,4-Michael addn. reaction between the ortho position of the catechol phenolic hydroxyl group of PD and Eschenmoser groups in the dyes. The adsorption isotherms were explored according to the Langmuir and Freundlich models resp., and matched well with the Langmuir model. The thermodn. parameters (ΔH, ΔG, ΔS, and E) were also calcd., which suggested an exothermic and spontaneous adsorption process. In addn., PD/GO exhibited an improved adsorption capacity for removal of heavy metal ions (Pb2+ 53.6, Cu2+ 24.4, Cd2+ 33.3, and Hg2+ 15.2 mg/g, resp.) than pure PD and GO. Our results indicate the effectiveness of the synergistic effect of individual components on designing new functional composites with high performance.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXkt1yrsLc%253D&md5=0a6bd1147723422377afbd2cf3d3cb26
383. 383
  Mondal, T.; Bhowmick, A. K.; Krishnamoorti, R. Synthesis and Characterization of Bi-Functionalized Graphene and Expanded Graphite Using n-butyl Lithium and Their Use for Efficient Water Soluble Dye Adsorption J. Mater. Chem. A 2013, 1, 8144– 8153 DOI: 10.1039/c3ta11212h
  
  383
  Synthesis and characterization of bi-functionalized graphene and expanded graphite using n-butyl lithium and their use for efficient water soluble dye adsorption
  
  Mondal, Titash; Bhowmick, Anil K.; Krishnamoorti, Ramanan
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2013), 1 (28), 8144-8153CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Two effects of an organolithium reagent (n-Bu lithium) on graphene and expanded graphite are reported. Its ability to simultaneously scavenge protons and act as a nucleophile leads to a bi-functionalized graphitic system. Subsequent treatment with CO2 gas generates carboxylic functionality at the proton abstraction sites. This technique promises a greener method for single pot carboxylation for graphitic materials. The nucleophilicity of Bu lithium leads to efficient grafting of Bu groups. FTIR spectroscopy, XPS and thermogravimetric anal. are used to prove the success of the reaction. Raman spectroscopy reveals more defect sites for expanded graphite compared to graphene, which leads to a higher degree of functionalization. Atomic force microscopy shows that the functional groups generated are nano-spike-shaped pendant structures attached to the graphene. These functionalized materials are used as adsorbers for efficient and fast removal of water-sol. dyes by non-covalent interaction between the dye and the carboxylic groups of the graphitic system. Spectrometric as well as kinetic studies are reported for Crystal Violet Lactone dye adsorption. Both the modified materials show twice the adsorption capacity of the pristine materials. Superior dye adsorption properties were obsd. for the modified materials compared to graphene oxide.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtVWmtLvJ&md5=7c2d85a5bfc1adbe6d2b266927ffeb52
384. 384
  Liang, R.; Shen, L.; Jing, F.; Qin, N.; Wu, L. Preparation of MIL-53(Fe)-Reduced Graphene Oxide Nanocomposites by a Simple Self-Assembly Strategy for Increasing Interfacial Contact: Efficient Visible-Light Photocatalysts ACS Appl. Mater. Interfaces 2015, 7, 9507– 9515 DOI: 10.1021/acsami.5b00682
  
  384
  Preparation of MIL-53(Fe)-Reduced Graphene Oxide Nanocomposites by a Simple Self-Assembly Strategy for Increasing Interfacial Contact: Efficient Visible-Light Photocatalysts
  
  Liang, Ruowen; Shen, Lijuan; Jing, Fenfen; Qin, Na; Wu, Ling
  
  ACS Applied Materials & Interfaces (2015), 7 (18), 9507-9515CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  In this work, MIL-53(Fe)-reduced graphene oxide (M53-RGO) nanocomposites have been successfully fabricated by a facile and efficient electrostatic self-assembly strategy for improving the interfacial contact between RGO and the MIL-53(Fe). Compared with D-M53-RGO (direct synthesis of MIL-53(Fe)-reduced graphene oxide nanocomposites via one-pot Solvo-thermal approach), M53-RGO nanocomposites exhibit improved photocatalytic activity compared with the D-M53-RGO under identical exptl. conditions. After 80 min of visible light illumination (λ ≥ 420 nm), the redn. ratio of Cr(VI) is rapidly increased to 100%, which is also higher than that of ref. sample (N-doped TiO2). More significantly, the M53-RGO nanocomposites are proven to perform as bifunctional photocatalysts with considerable activity in the mixed systems (Cr(VI)/dyes) under visible light, which made it a potential candidate for industrial wastewater treatment. Combining with photoelectrochem. analyses, it could be revealed that the introduction of RGO would minimize the recombination of photogenerated electron-hole pairs. Addnl., the effective interfacial contact between MIL-53(Fe) and RGO surface would further accelerate the transfer of photogenerated electrons, leading to the enhancement of photocatalytic activity of M53-RGO toward photocatalytic reactions. Finally, a possible photocatalytic reaction mechanism is also investigated in detail.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmvVygtLk%253D&md5=1853feefd30b837880b29e97a0a23e66
385. 385
  Qi, X.; Tan, C.; Wei, J.; Zhang, H. Synthesis of Graphene-Conjugated Polymer Nanocomposites for Electronic Device Applications Nanoscale 2013, 5, 1440– 1451 DOI: 10.1039/c2nr33145d
  
  385
  Synthesis of graphene-conjugated polymer nanocomposites for electronic device applications
  
  Qi, Xiaoying; Tan, Chaoliang; Wei, Jun; Zhang, Hua
  
  Nanoscale (2013), 5 (4), 1440-1451CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  A review. Graphene-based polymer nanocomposites have attracted increasing interest because of their superior physicochem. properties over polymers. Semiconductor conjugated polymers (CPs) with excellent dispersibility and stability, and efficient electronic and optical properties have been recently integrated with graphene to form a new class of functional nanomaterials. In this minireview, we will summarize the recent advances in the development of graphene-CP nanocomposites for electronic device applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhvFGlt7k%253D&md5=a27bde3371eb8d1873ce1d4d2c63eee9
386. 386
  Lu, H.; Yao, Y.; Huang, W. M.; Hui, D. Noncovalently Functionalized Carbon Fiber by Grafted Self-Assembled Graphene Oxide and the Synergistic Effect on Polymeric Shape Memory Nanocomposites Composites, Part B 2014, 67, 290– 295 DOI: 10.1016/j.compositesb.2014.07.022
  
  386
  Noncovalently functionalized carbon fiber by grafted self-assembled graphene oxide and the synergistic effect on polymeric shape memory nanocomposites
  
  Lu, Haibao; Yao, Yongtao; Huang, Wei Min; Hui, David
  
  Composites, Part B: Engineering (2014), 67 (), 290-295CODEN: CPBEFF; ISSN:1359-8368. (Elsevier Ltd.)
  
  This paper presents an effective approach to significantly improve the elec. properties and recovery performance of shape memory polymer (SMP) nanocomposites that are able for Joule heating triggered shape recovery. Reduced graphene oxide (GO) is self-assembled and grafted onto the carbon fibers to enhance the interfacial bonding with the SMP matrix via Van der Waals and covalent crosslink, resp. Exptl. results verify that the elec. properties of SMP nanocomposites are significantly improved via a synergistic effect of GO and carbon fiber. The morphol. and porous structure of GO on the carbon fiber are characterized by electron microscope and optical microscopes, resp. Furthermore, the behavior of electro-activated recovery and the resultant temp. distribution within SMP nanocomposite are monitored and characterized. We demonstrate that this simple way is able to produce electro-activated SMP nanocomposites which are applicable for Joule heating at a lower elec. voltage.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtlahtL7M&md5=1804f5c15771ff7f13221c9a85e629e5
387. 387
  Lu, H.; Liang, F.; Gou, J.; Leng, J.; Du, S. Synergistic Effect of Ag Nanoparticle-Decorated Graphene Oxide and Carbon Fiber on Electrical Actuation of Polymeric Shape Memory Nanocomposites Smart Mater. Struct. 2014, 23, 085034 DOI: 10.1088/0964-1726/23/8/085034
  
  387
  Synergistic effect of Ag nanoparticledecorated graphene oxide and carbon fiber on electrical actuation of polymeric shape memory nanocomposites
  
  Lu, Haibao; Liang, Fei; Gou, Jihua; Leng, Jinsong; Du, Shanyi
  
  Smart Materials and Structures (2014), 23 (8), 085034CODEN: SMSTER; ISSN:1361-665X. (IOP Publishing Ltd.)
  
  This study reports an effective approach of significantly improving elec. properties and recovery performance of shape memory polymer (SMP) nanocomposite, of which its shape recovery was triggered by elec. resistive Joule heating. Reduced graphene oxide (GOs) self-assembled and grafted onto carbon fiber, were used to enhance the interfacial bonding with the SMP matrix via van der Waals force and covalent bond, resp. A layer of Ag nanoparticles was synthesized from Ag+ soln. and chem. deposited onto GO assemblies. These Ag nanoparticles were expected to bridge the gap between GO and improve the elec. cond. The exptl. results reveal that the elec. cond. of the SMP nanocomposite was significantly improved via the synergistic effect between Ag nanoparticle-decorated GO and carbon fiber. Finally, the elec. induced shape memory effect of the SMP nanocomposite was achieved, and the temp. distribution in the SMP nanocomposites was recorded and monitored. An effective approach was demonstrated to produce the electroactivated SMP nanocomposites and the resistive Joule heating was viable at a low elec. voltage below 10 V.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslCnt7fM&md5=7222c93b783e19a5dfe5332ff6421b8c
388. 388
  Love, J. C.; Estroff, L. A.; Kriebel, J. K.; Nuzzo, R. G.; Whitesides, G. M. Self-Assembled Monolayers of Thiolates on Metals as a Form of Nanotechnology Chem. Rev. 2005, 105, 1103– 1169 DOI: 10.1021/cr0300789
  
  388
  Self-Assembled Monolayers of Thiolates on Metals as a Form of Nanotechnology
  
  Love, J. Christopher; Estroff, Lara A.; Kriebel, Jennah K.; Nuzzo, Ralph G.; Whitesides, George M.
  
  Chemical Reviews (Washington, DC, United States) (2005), 105 (4), 1103-1169CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)
  
  A review. This article presents the complete review on the formation, structure, property, and potential application of self-assembled monolayer of thiolate on metal surface.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2MXis1ahsrc%253D&md5=f734cb3bf2643ececb8acc01b3adafb6
389. 389
  Schedin, F.; Geim, A. K.; Morozov, S. V.; Hill, E. W.; Blake, P.; Katsnelson, M. I.; Novoselov, K. S. Detection of Individual Gas Molecules Adsorbed on Graphene Nat. Mater. 2007, 6, 652– 655 DOI: 10.1038/nmat1967
  
  389
  Detection of individual gas molecules adsorbed on graphene
  
  Schedin, F.; Geim, A. K.; Morozov, S. V.; Hill, E. W.; Blake, P.; Katsnelson, M. I.; Novoselov, K. S.
  
  Nature Materials (2007), 6 (9), 652-655CODEN: NMAACR; ISSN:1476-1122. (Nature Publishing Group)
  
  Authors show that micrometre-size sensors made from graphene are capable of detecting individual events when a gas mol. attaches to or detaches from graphene's surface. The adsorbed mols. change the local carrier concn. in graphene one by one electron, which leads to step-like changes in resistance. The achieved sensitivity is due to the fact that graphene is an exceptionally low-noise material electronically, which makes it a promising candidate not only for chem. detectors but also for other applications where local probes sensitive to external charge, magnetic field or mech. strain are required.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXpvFKjsrs%253D&md5=dedbfc7b95a13316bcbb8ebc5956c1d3
390. 390
  Wang, X.; Li, X.; Zhang, L.; Yoon, Y.; Weber, P. K.; Wang, H.; Guo, J.; Dai, H. N-Doping of Graphene Through Electrothermal Reactions with Ammonia Science 2009, 324, 768– 771 DOI: 10.1126/science.1170335
  
  390
  N-doping of graphene through electrothermal reactions with ammonia
  
  Wang, Xinran; Li, Xiaolin; Zhang, Li; Yoon, Youngki; Weber, Peter K.; Wang, Hailiang; Guo, Jing; Dai, Hongjie
  
  Science (Washington, DC, United States) (2009), 324 (5928), 768-771CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)
  
  Graphene is readily p-doped by adsorbates, but for device applications, it would be useful to access the n-doped material. Individual graphene nanoribbons were covalently functionalized by N species through high-power elec. Joule heating in NH3 gas, leading to n-type electronic doping consistent with theory. The formation of the C-N bond should occur mostly at the edges of graphene where chem. reactivity is high. XPS and nanometer-scale secondary ion mass spectroscopy confirm the C-N species in graphene thermally annealed in NH3. We fabricated an n-type graphene field-effect transistor that operates at room temp.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXlsVelu7Y%253D&md5=6a7e6044aa6012fb08f599dcee2ae2d4
391. 391
  Joo, P.; Kim, B. J.; Jeon, E. K.; Cho, J. H.; Kim, B.-S. Optical Switching of the Dirac Point in Graphene Multilayer Field-Effect Transistors Functionalized with Spiropyran Chem. Commun. 2012, 48, 10978– 10980 DOI: 10.1039/c2cc35933b
  
  391
  Optical switching of the Dirac point in graphene multilayer field-effect transistors functionalized with spiropyran
  
  Joo, Piljae; Kim, Beom Joon; Jeon, Eun Kyung; Cho, Jeong Ho; Kim, Byeong-Su
  
  Chemical Communications (Cambridge, United Kingdom) (2012), 48 (89), 10978-10980CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)
  
  A facile method for achieving optical switching of the Dirac point and conductance in reduced graphene oxide multilayer FETs that are non-covalently functionalized with a photo-responsive spiropyran deriv. is presented. The photoresponsive transition from spiropyran to merocyanine induces the reversible optical switching in graphene based FETs.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhsFSrtLbF&md5=959ffe3bb6d0312b59ee9a2de7adbac1
392. 392
  Li, B.; Klekachev, A. V.; Cantoro, M.; Huyghebaert, C.; Stesmans, A.; Asselberghs, I.; De Gendt, S.; De Feyter, S. Toward Tunable Doping in Graphene FETs by Molecular Self-Assembled Monolayers Nanoscale 2013, 5, 9640– 9644 DOI: 10.1039/c3nr01255g
  
  392
  Toward tunable doping in graphene FETs by molecular self-assembled monolayers
  
  Li, Bing; Klekachev, Alexander V.; Cantoro, Mirco; Huyghebaert, Cedric; Stesmans, Andre; Asselberghs, Inge; De Gendt, Stefan; De Feyter, Steven
  
  Nanoscale (2013), 5 (20), 9640-9644CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  In this paper, we report the formation of self-assembled monolayers (SAMs) of oleylamine (OA) on highly oriented pyrolytic graphite (HOPG) and graphene surfaces and demonstrate the potential of using such org. SAMs to tailor the electronic properties of graphene. Mol. resoln. Atomic Force Microscopy (AFM) and Scanning Tunneling Microscopy (STM) images reveal the detailed mol. ordering. The elec. measurements show that OA strongly interacts with graphene leading to n-doping effects in graphene devices. The doping levels are tunable by varying the OA deposition conditions. Importantly, neither hole nor electron mobilities are decreased by the OA modification. As a benefit from this noncovalent modification strategy, the pristine characteristics of the device are recoverable upon OA removal. From this study, one can envision the possibility to correlate the graphene-based device performance with the mol. structure and supramol. ordering of the org. dopant.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFalt7zO&md5=8957414b90fdba82427f195fa9a59910
393. 393
  Long, B.; Manning, M.; Burke, M.; Szafranek, B. N.; Visimberga, G.; Thompson, D.; Greer, J. C.; Povey, I. M.; MacHale, J.; Lejosne, G. Non-Covalent Functionalization of Graphene Using Self-Assembly of Alkane-Amines Adv. Funct. Mater. 2012, 22, 717– 725 DOI: 10.1002/adfm.201101956
  
  393
  Non-Covalent Functionalization of Graphene Using Self-Assembly of Alkane-Amines
  
  Long, Brenda; Manning, Mary; Burke, Micheal; Szafranek, Bartholomaeus N.; Visimberga, Giuseppe; Thompson, Damien; Greer, James C.; Povey, Ian M.; MacHale, John; Lejosne, Guaylord; Neumaier, Daniel; Quinn, Aidan J.
  
  Advanced Functional Materials (2012), 22 (4), 717-725CODEN: AFMDC6; ISSN:1616-301X. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A simple, versatile method for noncovalent functionalization of graphene based on soln.-phase assembly of alkane-amine layers is presented. Second-order Moller-Plesset (MP2) perturbation theory on a cluster model (methylamine on pyrene) yields a binding energy of ≈220 meV for the amine-graphene interaction, which is strong enough to enable formation of a stable aminodecane layer at room temp. Atomistic mol. dynamics simulations on an assembly of 1-aminodecane mols. indicate that a self-assembled monolayer can form, with the alkane chains oriented perpendicular to the graphene basal plane. The calcd. monolayer height (≈1.7 nm) is in good agreement with at. force microscopy data acquired for graphene functionalized with 1-aminodecane, which yield a continuous layer with mean thickness ≈1.7 nm, albeit with some island defects. Raman data also confirm that self-assembly of alkane-amines is a noncovalent process, i.e., it does not perturb the sp2 hybridization of the graphene. Passivation and adsorbate n-doping of graphene field-effect devices using 1-aminodecane, as well as high-d. binding of plasmonic metal nanoparticles and seeded at. layer deposition of inorg. dielecs. using 1,10-diaminodecane are also reported.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhs1ert7fI&md5=964d2252186b0008a0aa148bd8cfde32
394. 394
  Wang, H.; Bi, S.-G.; Ye, Y.-S.; Xue, Y.; Xie, X.-L.; Mai, Y.-W. An Effective Non-Covalent Grafting Approach to Functionalize Individually Dispersed Reduced Graphene Oxide Sheets with High Grafting Density, Solubility and Electrical Conductivity Nanoscale 2015, 7, 3548– 3557 DOI: 10.1039/C4NR06710J
  
  394
  An effective non-covalent grafting approach to functionalize individually dispersed reduced graphene oxide sheets with high grafting density, solubility and electrical conductivity
  
  Wang, Hao; Bi, Shu-Guang; Ye, Yun-Sheng; Xue, Yang; Xie, Xiao-Lin; Mai, Yiu-Wing
  
  Nanoscale (2015), 7 (8), 3548-3557CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  Polymer-functionalized reduced graphene oxide (polymer-FG), produced as individually dispersed graphene sheets, offers new possibilities for the prodn. of nanomaterials that are useful for a broad range of potential applications. Although non-covalent functionalization has produced graphene with good dispersibility and a relatively complete conjugated network, there are few reports related to the effective functionalization of reduced graphene oxide (RGO) using a simple, general method. Herein, we report a facile and effective approach for the prepn. of polymer-FG from a non-covalently functionalized pyrene-terminal polymer in benzoyl alc. (BnOH). This arom. alc. (BnOH) was used as the liq. medium for the dispersion of graphene oxide (GO) with a pyrene-terminal polymer, and as an effective reductant; this makes the synthesis procedure convenient and the prodn. of polymer-FG easily scalable because the conversion of GO to RGO and the non-covalent functionalization proceed simultaneously. The resulting polymer-FG sheets show organo-dispersibility, high elec. cond. and good processability, and have a similar grafting d. comparable to covalently made materials, thus making them promising candidates for applications such as electrochem. devices, nanomaterials and polymer nanocomposites. Hence, this work provides a general methodol. for prepg. individually dispersed graphene sheets with desirable properties.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXmtlCgsg%253D%253D&md5=50f620fcac686ab36857190416c9abf0
395. 395
  Kozhemyakina, N. V.; Englert, J. M.; Yang, G.; Spiecker, E.; Schmidt, C. D.; Hauke, F.; Hirsch, A. Non-Covalent Chemistry of Graphene: Electronic Communication with Dendronized Perylene Bisimides Adv. Mater. 2010, 22, 5483– 5487 DOI: 10.1002/adma.201003206
  
  395
  Non-Covalent Chemistry of Graphene: Electronic Communication with Dendronized Perylene Bisimides
  
  Kozhemyakina, Nina V.; Englert, Jan M.; Yang, Guang; Spiecker, Erdmann; Schmidt, Cordula D.; Hauke, Frank; Hirsch, Andreas
  
  Advanced Materials (Weinheim, Germany) (2010), 22 (48), 5483-5487CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  We have demonstrated the binding and electronic interactions of graphene with dendronized perylene bisimides in homogeneous soln. Previously, this had been obsd. only in the solid state. This result opens the door for the non-covalent functionalization of graphene in org. solvents.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhsFGlt7%252FM&md5=f1d91b6718897f7905592832861b8ea0
396. 396
  Parvez, K.; Li, R.; Puniredd, S. R.; Hernandez, Y.; Hinkel, F.; Wang, S.; Feng, X.; Muellen, K. Electrochemically Exfoliated Graphene as Solution-Processable, Highly Conductive Electrodes for Organic Electronics ACS Nano 2013, 7, 3598– 3606 DOI: 10.1021/nn400576v
  
  396
  Electrochemically Exfoliated Graphene as Solution-Processable, Highly Conductive Electrodes for Organic Electronics
  
  Parvez, Khaled; Li, Rongjin; Puniredd, Sreenivasa Reddy; Hernandez, Yenny; Hinkel, Felix; Wang, Suhao; Feng, Xinliang; Mullen, Klaus
  
  ACS Nano (2013), 7 (4), 3598-3606CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Soln.-processable thin layer graphene is an intriguing nanomaterial with tremendous potential for electronic applications. Electrochem. exfoliation of graphite furnishes graphene sheets of high quality. The electrochem. exfoliated graphene (EG) contains a high yield (>80%) of 1- to three-layer graphene flakes with high C/O ratio of 12.3 and low sheet resistance (4.8 kΩ/<<rar for a single EG sheet). Due to the soln. processability of EG, a vacuum filtration method in assocn. with dry transfer is introduced to produce large-area and highly conductive graphene films on various substrates. Also, the patterned EG can serve as high-performance source/drain electrodes for org. field-effect transistors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXkslWgt7k%253D&md5=8de9ed84d44ffcd61690e2f330d71dae
397. 397
  Woszczyna, M.; Winter, A.; Grothe, M.; Willunat, A.; Wundrack, S.; Stosch, R.; Weimann, T.; Ahlers, F.; Turchanin, A. All-Carbon Vertical van der Waals Heterostructures: Non-destructive Functionalization of Graphene for Electronic Applications Adv. Mater. 2014, 26, 4831– 4837 DOI: 10.1002/adma.201400948
  
  397
  All-Carbon Vertical van der Waals Heterostructures: Non-Destructive Functionalization of Graphene for Electronic Applications
  
  Woszczyna, Miroslaw; Winter, Andreas; Grothe, Miriam; Willunat, Annika; Wundrack, Stefan; Stosch, Rainer; Weimann, Thomas; Ahlers, Franz; Turchanin, Andrey
  
  Advanced Materials (Weinheim, Germany) (2014), 26 (28), 4831-4837CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Here we present a route to functionalization via engineering of all-carbon vertical heterostructures by mech. stacking of amino-terminated carbon nanomembrane (NH2-CNM) and single-layer graphene (SLG) sheets. CNMs are a novel two-dimensional (2D) carbon-based electronic material with dielec. properties made via electron-/photon-induced crosslinking of polycyclic arom. self-assembled monolayers.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXosV2mtrY%253D&md5=a23573988430effbfaaef1abeace0345
398. 398
  Nottbohm, C. T.; Turchanin, A.; Beyer, A.; Stosch, R.; Goelzhaeuser, A. Mechanically Stacked 1-nm-Thick Carbon Nanosheets: Ultrathin Layered Materials with Tunable Optical, Chemical, and Electrical Properties Small 2011, 7, 874– 883 DOI: 10.1002/smll.201001993
  
  398
  Mechanically stacked 1-nm-thick carbon nanosheets. Ultrathin layered materials with tunable optical, chemical, and electrical properties
  
  Nottbohm, Christoph T.; Turchanin, Andrey; Beyer, Andre; Stosch, Rainer; Goelzhaeuser, Armin
  
  Small (2011), 7 (7), 874-883CODEN: SMALBC; ISSN:1613-6810. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  C nanosheets are mech. stable, free-standing 2-dimensional materials with a thickness of ≈1 nm and well defined phys. and chem. properties. They are made by radiation-induced crosslinking of arom. self-assembled monolayers. Herein, a route is presented to the scalable fabrication of multilayer nanosheets with tunable elec., optical, and chem. properties on insulating substrates. Stacks of ≤5 nanosheets with sizes of ≈1 cm2 on oxidized Si are studied. Their optical characteristics are investigated by visual inspection, optical microscopy, UV-vis reflection spectroscopy, and model calcns. Their chem. compn. is studied by XPS. The multilayer samples are then annealed in an ultrahigh vacuum at various temps. ≤1100 K. A subsequent investigation by Raman, x-ray photoelectron, and UV-vis reflection spectroscopy, as well as by elec. 4-point probe measurements, demonstrates that the layered nanosheets transform into nanocryst. graphene. This structural and chem. transformation is accompanied by changes in the optical properties and elec. cond. and opens up a new path for the fabrication of ultrathin functional conductive coatings.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXktFKnurc%253D&md5=8c59238736b632a05bfc5170a0e765e8
399. 399
  Wang, Z. X.; Eigler, S.; Ishii, Y.; Hu, Y. C.; Papp, C.; Lytken, O.; Steinruck, H. P.; Halik, M. A Facile Approach to Synthesize an Oxo-Functionalized Graphene/Polymer Composite for Low-Voltage Operating Memory Devices J. Mater. Chem. C 2015, 3, 8595– 8604 DOI: 10.1039/C5TC01861G
  
  399
  A facile approach to synthesize an oxo-functionalized graphene/polymer composite for low-voltage operating memory devices
  
  Wang, Zhenxing; Eigler, Siegfried; Ishii, Yoshitaka; Hu, Yichen; Papp, Christian; Lytken, Ole; Steinrueck, Hans-Peter; Halik, Marcus
  
  Journal of Materials Chemistry C: Materials for Optical and Electronic Devices (2015), 3 (33), 8595-8604CODEN: JMCCCX; ISSN:2050-7534. (Royal Society of Chemistry)
  
  Memory devices are a key technol. of the authors' era and one of the const. challenges is the redn. of their power consumption. Herein, graphene oxide with very few defects, i.e., ∼1 nm thin oxo-functionalized graphene deriv., can be used in memory devices operating at 3 V. A memory device stores charges in the material of the active channel. Thereby, writing and erasing information can be performed at low voltage, facilitating low power consumption. To enable operation at low voltage, a novel synthetic approach is necessary. The selective noncovalent electrostatic functionalization of mainly organosulfate ions is possible with dodecylammonium. This functionalization allows the noncovalent coating of flakes with a polystyrene-deriv. as nm-thin dielec. medium. The resulting polymer-wrapped composite has a height of ∼5 nm. The thin coating of a few nm is mandatory to make the memory device work at low voltage. Also, a self-assembled monolayer of an imidazolium deriv. further enhances the function of the memory device. The prepd. composite materials were characterized by state-of-the-art anal. including solid state NMR spectroscopy and TGA coupled with gas chromatog., mass spectroscopy or IR spectroscopy. Ref. expts. prove the importance of the controlled synthesis to enable the function of the memory device.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhtFyqtrvL&md5=b08aa4044d842c0e693c08345d747de0
400. 400
  Roth, A.; Ragoussi, M.-E.; Wibmer, L.; Katsukis, G.; de la Torre, G.; Torres, T.; Guldi, D. M. Electron-Accepting Phthalocyanine Pyrene Conjugates: Towards Liquid Phase Exfoliation of Graphite and Photoactive Nanohybrid Formation with Graphene Chem. Sci. 2014, 5, 3432– 3438 DOI: 10.1039/C4SC00709C
  
  400
  Electron-accepting phthalocyanine-pyrene conjugates: towards liquid phase exfoliation of graphite and photoactive nanohybrid formation with graphene
  
  Roth, Alexandra; Ragoussi, Maria-Eleni; Wibmer, Leonie; Katsukis, Georgios; de la Torre, Gema; Torres, Tomas; Guldi, Dirk M.
  
  Chemical Science (2014), 5 (9), 3432-3438CODEN: CSHCCN; ISSN:2041-6520. (Royal Society of Chemistry)
  
  Herein, we describe the synthesis of a zinc(II) alkylsulfonylphthalocyanine-pyrene conjugate, its assembly with highly exfoliated graphite, and the investigation of the photophys. properties of the resulting nanohybrid. The presence of the pyrene unit in the conjugate is decisive in terms of non-covalently immobilizing the electron accepting phthalocyanines onto the basal plane of highly exfoliated graphite. As a matter of fact, strong interactions dominate the electronic properties of the nanohybrid in both the ground and excited states. For example, femtosecond pump probe expts. assist in corroborating an ultrafast charge sepn., i.e., the generation of the one-electron reduced radical anion of the phthalocyanine and one-electron oxidized graphene after irradn. at 387 nm, followed by slow charge recombination.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtValsrnO&md5=12ad240dfaffb6eca3fe405c9ccc9c10
401. 401
  Wang, Z.; Hu, G.; Liu, J.; Liu, W.; Zhang, H.; Wang, B. Coordinated Assembly of a New 3D Mesoporous Fe₃O₄@Cu₂O-Graphene Oxide Framework as a Highly Efficient and Reusable Catalyst for the Synthesis of Quinoxalines Chem. Commun. 2015, 51, 5069– 5072 DOI: 10.1039/C5CC00250H
  
  There is no corresponding record for this reference.
402. 402
  Ren, R.; Li, S.; Li, J.; Ma, J.; Liu, H.; Ma, J. Enhanced Catalytic Activity of Au Nanoparticles Self-Assembled on Thiophenol Functionalized Graphene Catal. Sci. Technol. 2015, 5, 2149– 2156 DOI: 10.1039/C4CY01620C
  
  402
  Enhanced catalytic activity of Au nanoparticles self-assembled on thiophenol functionalized graphene
  
  Ren, Ren; Li, Shuwen; Li, Jing; Ma, Jianxin; Liu, Hengzhi; Ma, Jiantai
  
  Catalysis Science & Technology (2015), 5 (4), 2149-2156CODEN: CSTAGD; ISSN:2044-4753. (Royal Society of Chemistry)
  
  A new catalyst contg. 1-2 nm Au nanoparticles anchored to thiophenol covalently functionalized graphene sheets (Au/TP-GS) was fabricated using a facile, synthetic approach. The details of the morphologies, size and dispersion of the Au nanoparticles (NPs) and the chem. compn. of the novel catalyst were verified by systematic characterization techniques, including transmission electron microscopy (TEM), high-resoln. transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray diffraction (XRD) and XPS. The resulting Au/TP-GS exhibited excellent catalytic activity for both the redn. of 4-nitrophenol and the photodegrdn. of Rhodamine B due to the synergistic effects between the TP-GS and Au NPs and the high utilization of the metal. The practical, efficient and facile in situ redn. approach to synthesize the nanocatalyst provides a more environmentally benign synthesis route to effectively produce low cost Au-based catalysts.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnvVamtA%253D%253D&md5=7319564121dac7892fbfd1bbbffd4b7f
403. 403
  Pathak, P.; Gupta, S.; Grosulak, K.; Imahori, H.; Subramanian, V. Nature-Inspired Tree-Like TiO₂ Architecture: A 3D Platform for the Assembly of CdS and Reduced Graphene Oxide for Photoelectrochemical Processes J. Phys. Chem. C 2015, 119, 7543– 7553 DOI: 10.1021/jp512160h
  
  403
  Nature-Inspired Tree-Like TiO2 Architecture: A 3D Platform for the Assembly of CdS and Reduced Graphene Oxide for Photoelectrochemical Processes
  
  Pathak, Pawan; Gupta, Satyajit; Grosulak, Kehley; Imahori, Hiroshi; Subramanian, Vaidyanathan
  
  Journal of Physical Chemistry C (2015), 119 (14), 7543-7553CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
  
  A nature-inspired tree-like 3-dimensional hierarchical TiO2/TiO2 architecture was prepd. as a facade to strategically assemble reduced graphene oxide/RGO (a facile charge transporter) and Cd sulfide/CdS (a visible light harvester) is presented for the 1st time. The core 3-dimensional TiO2 heterostructure was prepd. using a TiCl3 mediated surface treatment of TiO2 nanorods on F-doped Sn oxide (FTO) coated glass-slides. The performance of the 3-dimensional TiO2, which varies as a function of the treatment time, was 1st examd. to achieve optimal photoelectrochem. response. Subsequently, the architecture was tested for its (i) theor. H2O-splitting potential and (ii) ability to immobilize chalcogenide nonocrystals (CdS) with and without RGO. The best applied bias to photoconversion efficiency (% ABPE) is 0.36% (-0.15 V vs. Ag/AgCl) for the TiO2 architecture. A 140% increase with CdS deposition on the branched TiO2 indicated the structures' ability to effectively immobilize the chalcogenide. The effect of RGO on the photoelectrochem. response was explored and an optimum loading (1 mg mL-1) of RGO was noted to boost the photoresponse by an addnl. 150% compared to CdS-only photoanodes. Further, stability anal. performed over 3 h showed that the presence of RGO significantly delays CdS corrosion-driven deactivation. Finally, the fundamental insights on the impact of RGO in the 3-dimensional TiO2/RGO/CdS photoanode and its effect on the charge transportation mechanism were examd. using electrochem. impedance spectroscopy.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXislSnt7w%253D&md5=980d8fdd9fc7b9b7f2cc99856da1bdfd
404. 404
  Padhi, D. K.; Parida, K.; Singh, S. K. Facile Fabrication Of RGO/N-GZ Mixed Oxide Nanocomposite For Efficient Hydrogen Production Under Visible Light J. Phys. Chem. C 2015, 119, 6634– 6646 DOI: 10.1021/acs.jpcc.5b00311
  
  There is no corresponding record for this reference.
405. 405
  Ullah, K.; Ye, S.; Lei, Z.; Cho, K.-Y.; Oh, W.-C. Synergistic Effect of PtSe₂ and Graphene Sheets Supported by TiO₂ as Cocatalysts Synthesized via Microwave Techniques for Improved Photocatalytic Activity Catal. Sci. Technol. 2015, 5, 184– 198 DOI: 10.1039/C4CY00886C
  
  405
  Synergistic effect of PtSe2 and graphene sheets supported by TiO2 as cocatalysts synthesized via microwave techniques for improved photocatalytic activity
  
  Ullah, Kefayat; Ye, Shu; Lei, Zhu; Cho, Kwang-Yeon; Oh, Won-Chun
  
  Catalysis Science & Technology (2015), 5 (1), 184-198CODEN: CSTAGD; ISSN:2044-4753. (Royal Society of Chemistry)
  
  Here we report a new composite material consisting of TiO2 nanoparticles grown in the presence of a layered PtSe2/graphene hybrid as a high-performance photocatalytic material. The heterogeneous PtSe2-graphene/TiO2 nanocomposites were successfully synthesized through a facile and fast microwave-assisted method. The prepd. composites were characterized through x-ray diffraction (XRD), SEM (SEM) with energy dispersive x-ray (EDX) spectroscopy, transmission electron microscopy (TEM), Raman spectroscopic anal., XPS, and UV-vis absorbance spectra and UV-vis diffuse reflectance spectra (DRS) analyses were obtained. The catalytic behavior was investigated through the decompn. of Rhodamine B (Rh. B) as a std. dye and Texbrite MST-L as an industrial dye. This extraordinary photocatalytic activity arises from the pos. synergetic effect between the PtSe2 and graphene components in this heterogeneous photocatalyst. In this study the graphene behaves as an electron transfer agent, collector, contributor and a source of active adsorption sites. The optical properties were also obsd. to be affected by the different wt.% of graphene in the composites by observing their resp. band gaps from DRS spectra.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVGjur7L&md5=f69ecc2874d132b5b2e34339e8c1368e
406. 406
  Jiang, D.; Du, X.; Liu, Q.; Hao, N.; Qian, J.; Dai, L.; Mao, H.; Wang, K. Anchoring AgBr Nanoparticles on Nitrogen-Doped Graphene for Enhancement of Electrochemiluminescence and Radical Stability Chem. Commun. 2015, 51, 4451– 4454 DOI: 10.1039/C4CC09926E
  
  There is no corresponding record for this reference.
407. 407
  Joseph, K. L. V.; Lim, J.; Anthonysamy, A.; Kim, H.-I.; Choi, W.; Kim, J. K. Squaraine-Sensitized Composite of a Reduced Graphene Oxide/TiO₂Photocatalyst: pi-pi Stacking as a New Method of Dye Anchoring J. Mater. Chem. A 2015, 3, 232– 239 DOI: 10.1039/C4TA04313H
  
  407
  Squaraine-sensitized composite of a reduced graphene oxide/TiO2 photocatalyst: π-π stacking as a new method of dye anchoring
  
  Joseph, K. L. Vincent; Lim, Jonghun; Anthonysamy, A.; Kim, Hyoung-il; Choi, Wonyong; Kim, Jin Kon
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (1), 232-239CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  The authors synthesized a near IR (NIR)-absorbing squaraine dye (VJ-S) showing strong absorption and emission maxima at 684 and 704 nm, resp., with a high molar absorptivity (ε) of 1.277 × 105 M-1 cm-1 and a band gap of 1.77 eV. Its oxidn. and redn. potentials are 0.889 and -0.795 V, resp., with HOMO and LUMO levels of -5.21 and -3.53 eV, resp. The authors also prepd. the self-assembled core/shell nanocomposite r-NGOT, where TiO2 is the core and reduced nano-sized graphene oxide (r-NGO) is the shell. When VJ-S was anchored on r-NGOT, it showed π-π stacking with r-NGO, which is confirmed by Fourier-transformed IR spectroscopy, XPS, high-resoln. TEM and EELS. The optical absorption spectrum of the VJ-S/r-NGOT nanocomposite measured with diffuse reflectance UV/visible absorption spectroscopy covers the whole range of visible light wavelengths up to 800 nm. The photocatalytic activity of VJ-S/r-NGOT at visible light wavelengths (λ > 420 nm) is much higher than that of r-NGOT alone.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVemsLjL&md5=a66cb055f3a5a34ab2d15e364c154b25
408. 408
  Ma, H.; Tian, J.; Cui, L.; Liu, Y.; Bai, S.; Chen, H.; Shan, Z. Porous Activated Graphene Nanoplatelets Incorporated in TiO₂ Photoanodes for High-Efficiency Dye-Sensitized Solar Cells J. Mater. Chem. A 2015, 3, 8890– 8895 DOI: 10.1039/C5TA00527B
  
  408
  Porous activated graphene nanoplatelets incorporated in TiO2 photoanodes for high-efficiency dye-sensitized solar cells
  
  Ma, Huanmei; Tian, Jianhua; Cui, Lan; Liu, Yuanyuan; Bai, Shuming; Chen, Hang; Shan, Zhongqiang
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (16), 8890-8895CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Activated graphene nanoplatelets (a-GNPs) were first prepd. by a hydrothermal method with KOH as the activating agent. The effects of the prepn. conditions on the morphol. and structure of the a-GNPs were studied in detail. Morphol. observations and N2 adsorption-desorption isotherms indicate that the a-GNPs exhibit a uniform pore size distribution and have a larger sp. surface area (113.5 m2 g-1) compared to graphene nanoplatelets (GNPs). The incorporation of a-GNPs (0.02 wt%) into a TiO2 film photoanode in a dye-sensitized solar cell (DSSC) enhances the short circuit current and energy conversion of the cell by 35.8% and 26.8%, resp. The TiO2/a-GNP composite photoanodes were characterized by UV-vis spectroscopy and electrochem. impedance spectroscopy. The results reveal that the three-dimensional porous structure of a-GNPs serves as an efficient pathway for electrolyte ions and electrons, which accelerates the electron transfer and charge sepn., and suppresses the electron recombination and back transport reaction in DSSCs. However, excessive a-GNP incorporation leads to a decrease in the dye adsorption and thus a low energy conversion efficiency of DSSCs.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXkvFGjsrk%253D&md5=85293eecfdcf482b1bd0cb75d5e274c0
409. 409
  Xu, L.; Huang, W.-Q.; Wang, L.-L.; Tian, Z.-A.; Hu, W.; Ma, Y.; Wang, X.; Pan, A.; Huang, G.-F. Insights into Enhanced Visible-Light Photocatalytic Hydrogen Evolution of g-C₃N₄ and Highly Reduced Graphene Oxide Composite: The Role of Oxygen Chem. Mater. 2015, 27, 1612– 1621 DOI: 10.1021/cm504265w
  
  409
  Insights into Enhanced Visible-Light Photocatalytic Hydrogen Evolution of g-C3N4 and Highly Reduced Graphene Oxide Composite: The Role of Oxygen
  
  Xu, Liang; Huang, Wei-Qing; Wang, Ling-Ling; Tian, Ze-An; Hu, Wangyu; Ma, Yanming; Wang, Xin; Pan, Anlian; Huang, Gui-Fang
  
  Chemistry of Materials (2015), 27 (5), 1612-1621CODEN: CMATEX; ISSN:0897-4756. (American Chemical Society)
  
  The reduced graphene oxide (RGO)-based composites have attracted intensive attention in research due to its superior performance as photocatalysts, but still lacking is the theor. understanding on the interactions between constituents, as well as the connection between such interaction and the enhanced photoactivity. Herein, the interaction between the g-C3N4 and RGO sheets is systematically explored by using state-of-the-art hybrid d. functional theory. It is demonstrated that the O atom plays a crucial role in the RGO-based composites. Compared to the isolated g-C3N4 monolayer, the band gap of composites obviously decreases, and at higher O concn., the levels in the vicinity of Fermi level are much more dispersive, indicating the smaller effective mass of the carrier. These changes are nonlinear on the O concn. Interestingly, appropriate O concn. alters the direct-gap composite to indirect-gap one. Most importantly, at a higher O concn., a type-II, staggered band alignment can be obtained in the g-C3N4-RGO interface, and neg. charged O atoms in the RGO are active sites, leading to the high hydrogen-evolution activity. Furthermore, the calcd. absorption spectra which vary with the O concn. shed light on different exptl. results. The findings pave the way for developing RGO-based composites for photocatalytic applications.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitVerur4%253D&md5=987aae3bb083bdec4a5f7f37d0daeac8
410. 410
  Meng, F.; Cushing, S. K.; Li, J.; Hao, S.; Wu, N. Enhancement of Solar Hydrogen Generation by Synergistic Interaction of La₂Ti₂O₇ Photocatalyst with Plasmonic Gold Nanoparticles and Reduced Graphene Oxide Nanosheets ACS Catal. 2015, 5, 1949– 1955 DOI: 10.1021/cs5016194
  
  410
  Enhancement of Solar Hydrogen Generation by Synergistic Interaction of La2Ti2O7 Photocatalyst with Plasmonic Gold Nanoparticles and Reduced Graphene Oxide Nanosheets
  
  Meng, Fanke; Cushing, Scott K.; Li, Jiangtian; Hao, Shimeng; Wu, Nianqiang
  
  ACS Catalysis (2015), 5 (3), 1949-1955CODEN: ACCACS; ISSN:2155-5435. (American Chemical Society)
  
  This report shows that incorporating nitrogen-doped La2Ti2O7 (NLTO) photocatalyst with gold nanoparticles and reduced graphene oxide (rGO) nanosheets improves the photocatalytic hydrogen generation rate significantly. The underlying mechanism of the photocatalysis enhancement by the presence of both the Au nanoparticles and the rGO nanosheets is revealed. Nitrogen doping alone can extend the light absorption range of photocatalyst to 550 nm. In addn., nitrogen doping has enabled plasmon-induced resonance energy transfer (PIRET) from the plasmonic Au nanoparticle to NLTO, inducing charge sepn. in NLTO under solar radiation up to 600 nm. The Au nanoparticles not only serve as the photosensitizers but also lead to a shift in the flat band potential, suppressing the charge recombination and improving the charge extn. The rGO does not affect the charge sepn. process but significantly increases the lifetime of photogenerated charge carriers.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXis1Kgurs%253D&md5=e0fd6a26ea07e8c6801bbed93d35b705
411. 411
  Feifel, S. C.; Stieger, K. R.; Lokstein, H.; Lux, H.; Lisdat, F. High Photocurrent Generation by Photosystem I on Artificial Interfaces Composed of pi-System-Modified Graphene J. Mater. Chem. A 2015, 3, 12188– 12196 DOI: 10.1039/C5TA00656B
  
  411
  High photocurrent generation by photosystem I on artificial interfaces composed of π-system-modified graphene
  
  Feifel, S. C.; Stieger, K. R.; Lokstein, H.; Lux, H.; Lisdat, F.
  
  Journal of Materials Chemistry A: Materials for Energy and Sustainability (2015), 3 (23), 12188-12196CODEN: JMCAET; ISSN:2050-7496. (Royal Society of Chemistry)
  
  Photosystem I (PSI) is a key component of the oxygenic photosynthetic electron transport chain because of its light-induced charge sepn. and electron transfer (ET) capabilities. We report the fabrication of an efficient graphene-biohybrid light-harvesting electrode consisting of cyanobacterial trimeric PSI complexes immobilized onto π-system-modified graphene electrodes. Based on the strong interaction between conjugated arom. compds. and the graphene material via π-π-stacking, we have designed a simple but smart platform to fabricate light-driven photoelectrochem. devices. Due to the possibility of surface property adaptation and the excellent cond. of graphene, the modified biohybrid electrodes exhibit a well-defined photoelectrochem. response. In particular, the PSI-graphene electrode applying pyrene butyric acid NHS ester displays a very high photocurrent output of 23 μA cm-2 already at the open circuit potential which can be further increased by an overpotential and the use of an electron acceptor (Me viologen) under air satn. up to 135 μA cm-2. Comparing the graphene-PSI biohybrid systems based on different π-system-modifiers reveals that the pyrene derivs. result in higher current outputs compared to the anthracene derivs. and that the covalent fixation during immobilization appears more efficient compared to simple adsorption. Interestingly, the pyrene-based PSI electrodes also display a nearly unidirectional photocurrent generation, establishing the feasibility of conjoining these nanomaterials as potential constructs in next-generation photovoltaic devices.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXntVWksbk%253D&md5=6e72273eafb6370f50014ea1a13a5172
412. 412
  Moon, G.-H.; Kim, W.; Bokare, A. D.; Sung, N.-E.; Choi, W. Solar Production of H₂O₂ on Reduced Graphene Oxide-TiO₂ Hybrid Photocatalysts Consisting of Earth-Abundant Elements Only Energy Environ. Sci. 2014, 7, 4023– 4028 DOI: 10.1039/C4EE02757D
  
  412
  Solar production of H2O2 on reduced graphene oxide-TiO2 hybrid photocatalysts consisting of earth-abundant elements only
  
  Moon, Gun-hee; Kim, Wooyul; Bokare, Alok D.; Sung, Nark-eon; Choi, Wonyong
  
  Energy & Environmental Science (2014), 7 (12), 4023-4028CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)
  
  A superior cocatalytic behavior of reduced graphene oxide (rGO) was obsd. for the photocatalytic prodn. of H2O2 in the TiO2-based system. The adsorption of phosphate on TiO2 enhanced the prodn. of H2O2 up to a millimolar level. The in situ formation of cobalt phosphate on rGO/TiO2 enabled the photocatalytic prodn. of H2O2 even in the absence of org. electron donors.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslOisLjN&md5=8185af3bfbe59c0170734852f5a76b38
413. 413
  Lee, D. H.; Song, D.; Kang, Y. S.; Park, W. I. Three-Dimensional Monolayer Graphene and TiO₂ Hybrid Architectures for High-Efficiency Electrochemical Photovoltaic Cells J. Phys. Chem. C 2015, 119, 6880– 6885 DOI: 10.1021/acs.jpcc.5b00178
  
  413
  Three-Dimensional Monolayer Graphene and TiO2 Hybrid Architectures for High-Efficiency Electrochemical Photovoltaic Cells
  
  Lee, Dong Hyun; Song, Donghoon; Kang, Yong Soo; Park, Won Il
  
  Journal of Physical Chemistry C (2015), 119 (12), 6880-6885CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)
  
  Three-dimensional (3D), tubular-structured monolayer graphene networks were hybridized with TiO2 nanoparticular layer for futuristic and robust electrode applications. A continuous form of 3-dimensional graphene with good carrier mobility provides a direct pathway for electrons to the current collector for a photoanode in dye-sensitized solar cells. This characteristic feature, coupled with its energy level, ensures an enhanced charge collection efficiency. Particular attention was paid to the graphene surface functionalization and the effective loading of TiO2 nanoparticles to improve the light harvesting and minimize electron recombination for a photoanode. The optimal hybrid structure resulted in a 10% enhanced energy conversion efficiency, compared to the TiO2-based analog without graphene. The impedance spectra confirmed that the increase in photovoltaic performance was mainly driven by the efficient charge collection through the 3-dimensional, tubular-structured monolayer graphene. This new electrode prototype can serve as a good complement to conventional TiO2 nanostructures.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjvFygsL8%253D&md5=092abc48cd199ab3c7de3bed5417c745
414. 414
  Shah, S.; Yin, P. T.; Uehara, T. M.; Chueng, S. D.; Yang, L.; Lee, K. B. Guiding Stem Cell Differentiation into Oligodendrocytes Using Graphene-Nanofiber Hybrid Scaffolds Adv. Mater. 2014, 26, 3673– 3680 DOI: 10.1002/adma.201400523
  
  414
  Guiding stem cell differentiation into oligodendrocytes using graphene-nanofiber hybrid scaffolds
  
  Shah, Shreyas; Yin, Perry T.; Uehara, Thiers M.; Chueng, Sy-Tsong Dean; Yang, Letao; Lee, Ki-Bum
  
  Advanced Materials (Weinheim, Germany) (2014), 26 (22), 3673-3680CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Herein, we report the use of a graphene-based nanomaterial for the design of hybrid nanofibrous scaffolds to guide NSC differentiation into oligodendrocytes (Figure I). Graphene-based nanomaterials, such as graphene oxide (GO), have recently gained considerable interest for tissue engineering applications due to their favorable chem., elec. and mech. propνerties. Besides serving as a highly elastic and flexible structural reinforcement, substrates coated with GO have been demonstrated to promote the growth and differentiation of various stem cell lines, including induced PSCs, MSCs and NSCs. Based on these considerations, we demonstrate the use of GO as an effective coating material in combination with electrospun nanofibers for the selective differentiation of NSCs into oligodendrocytes. By varying the amt. of GO coating on the nanofibers, we obsd. a GO concn.-dependent change in the expression of key neural markers, wherein coating with a higher concn. of GO was seen to promote differentiation into mature oligodendrocytes. Further investigation into the role of GO-coating on the nanofibrous scaffolds showed the overexpression of a no. of key integrin-related intracellular signaling mols. that are known to promote oligodendrocyte differentiation in normal development.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXkslCqtLk%253D&md5=ea562dbd74ce5b054fed11daa6e54fe1
415. 415
  Kim, T. H.; Shah, S.; Yang, L.; Yin, P. T.; Hossain, M. K.; Conley, B.; Choi, J. W.; Lee, K. B. Controlling Differentiation of Adipose-Derived Stem Cells Using Combinatorial Graphene Hybrid-Pattern Arrays ACS Nano 2015, 9, 3780– 3790 DOI: 10.1021/nn5066028
  
  415
  Controlling Differentiation of Adipose-Derived Stem Cells Using Combinatorial Graphene Hybrid-Pattern Arrays
  
  Kim, Tae-Hyung; Shah, Shreyas; Yang, Letao; Yin, Perry T.; Hossain, Md. Khaled; Conley, Brian; Choi, Jeong-Woo; Lee, Ki-Bum
  
  ACS Nano (2015), 9 (4), 3780-3790CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Control of stem cell fate by modulating biophys. cues (e.g., micropatterns, nanopatterns, elasticity and porosity of the substrates) has emerged as an attractive approach in stem cell-based research. Here, we report a method for fabricating combinatorial patterns of graphene oxide (GO) to effectively control the differentiation of human adipose-derived mesenchymal stem cells (hADMSCs). In particular, GO line patterns were highly effective for modulating the morphol. of hADMSCs, resulting in enhanced differentiation of hADMSCs into osteoblasts. Moreover, by generating GO grid patterns, we demonstrate the highly efficient conversion of mesodermal stem cells to ectodermal neuronal cells (conversion efficiency = 30%), due to the ability of the grid patterns to mimic interconnected/elongated neuronal networks. This work provides an early demonstration of developing combinatorial graphene hybrid-pattern arrays for the control of stem cell differentiation, which can potentially lead to more effective stem cell-based treatment of incurable diseases/disorders.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXlvV2jsL8%253D&md5=225ca53d82f4f051a820334868a10a6a
416. 416
  Park, J.; Kim, B.; Han, J.; Oh, J.; Park, S.; Ryu, S.; Jung, S.; Shin, J.; Lee, B. S.; Hong, B. H. Graphene Oxide Flakes as a Cellular Adhesive: Prevention of Reactive Oxygen Species Mediated Death of Implanted Cells for Cardiac Repair ACS Nano 2015, 9, 4987– 4999 DOI: 10.1021/nn507149w
  
  416
  Graphene Oxide Flakes as a Cellular Adhesive: Prevention of Reactive Oxygen Species Mediated Death of Implanted Cells for Cardiac Repair
  
  Park, Jooyeon; Kim, Bokyoung; Han, Jin; Oh, Jaewon; Park, Subeom; Ryu, Seungmi; Jung, Subin; Shin, Jung-Youn; Lee, Beom Seob; Hong, Byung Hee; Choi, Donghoon; Kim, Byung-Soo
  
  ACS Nano (2015), 9 (5), 4987-4999CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Mesenchymal stem cell (MSC) implantation has emerged as a potential therapy for myocardial infarction (MI). However, the poor survival of MSCs implanted to treat MI has significantly limited the therapeutic efficacy of this approach. This poor survival is primarily due to reactive oxygen species (ROS) generated in the ischemic myocardium after the restoration of blood flow. ROS primarily causes the death of implanted MSCs by inhibiting the adhesion of the MSCs to extracellular matrixes at the lesion site (i.e., anoikis). In this study, we proposed the use of graphene oxide (GO) flakes to protect the implanted MSCs from ROS-mediated death and thereby improve the therapeutic efficacy of the MSCs. GO can adsorb extracellular matrix (ECM) proteins. The survival of MSCs, which had adhered to ECM protein-adsorbed GO flakes and were subsequently exposed to ROS in vitro or implanted into the ischemia-damaged and reperfused myocardium, significantly exceeded that of unmodified MSCs. Furthermore, the MSC engraftment improved by the adhesion of MSCs to GO flakes prior to implantation enhanced the paracrine secretion from the MSCs following MSC implantation, which in turn promoted cardiac tissue repair and cardiac function restoration. This study demonstrates that GO can effectively improve the engraftment and therapeutic efficacy of MSCs used to repair the injury of ROS-abundant ischemia and reperfusion by protecting implanted cells from anoikis.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXntlCms70%253D&md5=fb3ef2493f46de33e8483c7deae935af
417. 417
  Kang, S.; Park, J. B.; Lee, T. J.; Ryu, S.; Bhang, S. H.; La, W. G.; Noh, M. K.; Hong, B. H.; Kim, B. S. Covalent Conjugation of Mechanically Stiff Graphene Oxide Flakes to Three-Dimensional Collagen Scaffolds for Osteogenic Differentiation of Human Mesenchymal Stem Cells Carbon 2015, 83, 162– 172 DOI: 10.1016/j.carbon.2014.11.029
  
  417
  Covalent conjugation of mechanically stiff graphene oxide flakes to three-dimensional collagen scaffolds for osteogenic differentiation of human mesenchymal stem cells
  
  Kang, Seokyung; Park, Jong Bo; Lee, Tae-Jin; Ryu, Seungmi; Bhang, Suk Ho; La, Wan-Geun; Noh, Myung-Kyung; Hong, Byung Hee; Kim, Byung-Soo
  
  Carbon (2015), 83 (), 162-172CODEN: CRBNAH; ISSN:0008-6223. (Elsevier Ltd.)
  
  Mesenchymal stem cells (MSCs) preferentially differentiate to osteogenic lineage when cultured on mech. stiff substrates. However, collagen sponges, clin. approved scaffolds for bone regeneration, provide soft microenvironment to MSCs. Here, the authors demonstrate that the covalent conjugation of mech. stiff graphene oxide (GO) flakes to 3-dimensional (3D) collagen scaffolds improves the mech. properties of the scaffolds and promotes the osteogenic differentiation of human MSCs (hMSCs) cultured on the scaffolds. The covalent conjugation of GO flakes to collagen scaffolds increased the scaffold stiffness by 3-fold and did not cause cytotoxicity. HMSCs cultured on the GO-collagen scaffolds demonstrated significantly enhanced osteogenic differentiation compared to cells cultured on non-modified collagen scaffolds. The enhanced osteogenic differentiation obsd. on the stiffer scaffolds was likely mediated by MSC mechanosensing because mols. that are involved in cell adhesion to stiff substrates were either up-regulated or activated. The 3D GO-collagen scaffolds could offer a powerful platform for stem cell research and orthopedic regenerative medicine.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvF2htb7E&md5=827b29634c947bdba18708fb70cf7070
418. 418
  Tiwari, J. N.; Vij, V.; Kemp, K. C.; Kim, K. S. Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules ACS Nano 2016, 10, 46– 80 DOI: 10.1021/acsnano.5b05690
  
  418
  Engineered Carbon-Nanomaterial-Based Electrochemical Sensors for Biomolecules
  
  Tiwari, Jitendra N.; Vij, Varun; Kemp, K. Christian; Kim, Kwang S.
  
  ACS Nano (2016), 10 (1), 46-80CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  A review. The study of electrochem. behavior of bioactive mols. has become one of the most rapidly developing scientific fields. Biotechnol. and biomedical engineering fields have a vested interest in constructing more precise and accurate voltammetric/amperometric biosensors. One rapidly growing area of biosensor design involves incorporation of carbon-based nanomaterials in working electrodes, such as one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide. In this review article, the authors give a brief overview describing the voltammetric techniques and how these techniques are applied in biosensing, as well as the details surrounding important biosensing concepts of sensitivity and limits of detection. Building on these important concepts, the sensitivity and limit of detection can be tuned by including carbon-based nanomaterials in the fabrication of biosensors. The sensing of biomols. including glucose, dopamine, proteins, enzymes, uric acid, DNA, RNA, and H2O2 traditionally employs enzymes in detection; however, these enzymes denature easily, and as such, enzymeless methods are highly desired. Here the authors draw an important distinction between enzymeless and enzyme-contg. carbon-nanomaterial-based biosensors. The review ends with an outlook of future concepts that can be employed in biosensor fabrication, as well as limitations of already proposed materials and how such sensing can be enhanced. As such, this review can act as a roadmap to guide researchers toward concepts that can be employed in the design of next generation biosensors, while also highlighting the current advancements in the field.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhvVGiu7jI&md5=2a364e06b18b0f612fcd9bf343c26b4f
419. 419
  Gu, W.; Deng, X.; Gu, X.; Jia, X.; Lou, B.; Zhang, X.; Li, J.; Wang, E. Stabilized, Superparamagnetic Functionalized Graphene/Fe₃O₄@Au Nanocomposites for a Magnetically-Controlled Solid-State Electrochemiluminescence Biosensing Application Anal. Chem. 2015, 87, 1876– 1881 DOI: 10.1021/ac503966u
  
  419
  Stabilized, Superparamagnetic Functionalized Graphene/Fe3O4@Au Nanocomposites for a Magnetically-Controlled Solid-State Electrochemiluminescence Biosensing Application
  
  Gu, Wenling; Deng, Xi; Gu, Xiaoxiao; Jia, Xiaofang; Lou, Baohua; Zhang, Xiaowei; Li, Jing; Wang, Erkang
  
  Analytical Chemistry (Washington, DC, United States) (2015), 87 (3), 1876-1881CODEN: ANCHAM; ISSN:0003-2700. (American Chemical Society)
  
  Herein, a multifunctional nanoarchitecture has been developed by integrating the branched poly(ethylenimine) functionalized graphene/iron oxide hybrids (BGNs/Fe3O4) and luminol capped gold nanoparticles (luminol-AuNPs). The luminescent luminol-AuNPs as an electrochemiluminescence marker can be assembled on the nanocarrier of BGNs/Fe3O4 hybrids efficiently via the Au-N chem. bonds and electrostatic adsorption. Meanwhile, the multifunctional nanoarchitecture has been proved with excellent electron transfer, good stability, high emission intensity, etc. Furthermore, the authors successfully developed an ultrasensitive magnetically-controlled solid-state electrochemiluminescence (ECL) platform for label-free detn. of HeLa cells using this multifunctional nanocomposite. Excellent performance of the magnetically-controlled ECL biosensing platform has been achieved including a high sensitivity for HeLa cells with a linear range from 20 to 1 × 104 cells/mL, good stability, and reproducibility.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitFGrsrrP&md5=7020efde7c1b2b0e22b0f63b18db99e9
420. 420
  Bagheri, H.; Arab, S. M.; Khoshsafar, H.; Afkhami, A. A Novel Sensor for Sensitive Determination of Atropine Based on a Co₃O₄-Reduced Graphene Oxide Modified Carbon Paste Electrode New J. Chem. 2015, 39, 3875– 3881 DOI: 10.1039/C5NJ00133A
  
  420
  A novel sensor for sensitive determination of atropine based on a Co3O4-reduced graphene oxide modified carbon paste electrode
  
  Bagheri, Hasan; Arab, Seyedeh Maryam; Khoshsafar, Hosein; Afkhami, Abbas
  
  New Journal of Chemistry (2015), 39 (5), 3875-3881CODEN: NJCHE5; ISSN:1144-0546. (Royal Society of Chemistry)
  
  This paper has presented a novel strategy to carry out direct and sensitive detn. of atropine in complex matrixes based on the Co3O4-graphene modified carbon paste electrode. This novel nanostructure was characterized by different spectroscopic and electrochem. techniques including SEM, X-ray diffraction, Fourier transform IR spectroscopy and electrochem. impedance spectroscopy. The fabricated electrochem. sensor showed good electrochem. response towards atropine. Under the optimized conditions, the calibration curve for atropine concn. was linear in the range from 0.1 to 3.2 μmol L-1 with the detection limit of 0.03 μmol L-1. In addn., the practical anal. performance of the sensor was examd. by evaluating the selective detection of atropine in biol. fluids and pharmaceutical samples with satisfied recovery. Therefore, the prepd. sensor may hold great promise for fast, simple and sensitive detection and biomedical anal. of atropine in various real samples.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjvF2lsLc%253D&md5=60c93c7d4718cac4eaad4f999f463b8b
421. 421
  Yoon, H. J.; Kim, T. H.; Zhang, Z.; Azizi, E.; Pham, T. M.; Paoletti, C.; Lin, J.; Ramnath, N.; Wicha, M. S.; Hayes, D. F. Sensitive Capture of Circulating Tumour Cells by Functionalized Graphene Oxide Nanosheets Nat. Nanotechnol. 2013, 8, 735– 741 DOI: 10.1038/nnano.2013.194
  
  421
  Sensitive capture of circulating tumor cells by functionalized graphene oxide nanosheets
  
  Yoon, Hyeun Joong; Kim, Tae Hyun; Zhang, Zhuo; Azizi, Ebrahim; Pham, Trinh M.; Paoletti, Costanza; Lin, Jules; Ramnath, Nithya; Wicha, Max S.; Hayes, Daniel F.; Simeone, Diane M.; Nagrath, Sunitha
  
  Nature Nanotechnology (2013), 8 (10), 735-741CODEN: NNAABX; ISSN:1748-3387. (Nature Publishing Group)
  
  The spread of cancer throughout the body is driven by circulating tumor cells (CTCs). These cells detach from the primary tumor and move from the bloodstream to a new site of subsequent tumor growth. They also carry information about the primary tumor and have the potential to be valuable biomarkers for disease diagnosis and progression, and for the mol. characterization of certain biol. properties of the tumor. However, the limited sensitivity and specificity of current methods for measuring and studying these cells in patient blood samples prevents the realization of their full clin. potential. The use of microfluidic devices is a promising method for isolating CTCs. However, the devices are reliant on three-dimensional structures, which limits further characterization and expansion of cells on the chip. Here we demonstrate an effective approach to isolating CTCs from blood samples of pancreatic, breast and lung cancer patients, by using functionalized graphene oxide nanosheets on a patterned gold surface. CTCs were captured with high sensitivity at a low concn. of target cells (73 ± 32.4% at 3-5 cells per mL blood).
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhsFaksbzL&md5=a6ac26c2fdf8b2e6c93bd63f6634a934
422. 422
  Lerner, M. B.; Matsunaga, F.; Han, G. H.; Hong, S. J.; Xi, J.; Crook, A.; Perez-Aguilar, J. M.; Park, Y. W.; Saven, J. G.; Liu, R. Scalable Production of Highly Sensitive Nanosensors Based on Graphene Functionalized with a Designed G Protein-Coupled Receptor Nano Lett. 2014, 14, 2709– 2714 DOI: 10.1021/nl5006349
  
  422
  Scalable Production of Highly Sensitive Nanosensors Based on Graphene Functionalized with a Designed G Protein-Coupled Receptor
  
  Lerner, Mitchell B.; Matsunaga, Felipe; Han, Gang Hee; Hong, Sung Ju; Xi, Jin; Crook, Alexander; Perez-Aguilar, Jose Manuel; Park, Yung Woo; Saven, Jeffery G.; Liu, Renyu; Johnson, A. T. Charlie
  
  Nano Letters (2014), 14 (5), 2709-2714CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)
  
  We have developed a novel, all-electronic biosensor for opioids that consists of an engineered μ-opioid receptor protein, with high binding affinity for opioids, chem. bonded to a graphene field-effect transistor to read out ligand binding. A variant of the receptor protein that provided chem. recognition was computationally redesigned to enhance its soly. and stability in an aq. environment. A shadow mask process was developed to fabricate arrays of hundreds of graphene transistors with av. mobility of ∼1500 cm2 V-1 s-1 and yield exceeding 98%. The biosensor exhibits high sensitivity and selectivity for the target naltrexone, an opioid receptor antagonist, with a detection limit of 10 pg/mL.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXmsVGksb0%253D&md5=aff37c7564398e2c3d1e476ce5840df0
423. 423
  Singh, M.; Holzinger, M.; Tabrizian, M.; Winters, S.; Berner, N. C.; Cosnier, S.; Duesberg, G. S. Noncovalently Functionalized Monolayer Graphene for Sensitivity Enhancement of Surface Plasmon Resonance Immunosensors J. Am. Chem. Soc. 2015, 137, 2800– 2803 DOI: 10.1021/ja511512m
  
  423
  Noncovalently functionalized monolayer graphene for sensitivity enhancement of surface plasmon resonance immunosensors
  
  Singh, Meenakshi; Holzinger, Michael; Tabrizian, Maryam; Winters, Sinead; Berner, Nina C.; Cosnier, Serge; Duesberg, Georg S.
  
  Journal of the American Chemical Society (2015), 137 (8), 2800-2803CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  A highly efficient surface plasmon resonance (SPR) immunosensor is described using a functionalized single graphene layer on a thin gold film. The aim of this approach was two-fold: first, to amplify the SPR signal by growing graphene through chem. vapor deposition and, second, to control the immobilization of biotinylated cholera toxin antigen on copper coordinated nitrilotriacetic acid (NTA) using graphene as an ultrathin layer. The NTA groups were attached to graphene via pyrene derivs. implying π-π interactions. With this setup, an immunosensor for the specific antibody anticholera toxin with a detection limit of 4 pg mL-1 was obtained. In parallel, NTA polypyrrole films of different thicknesses were electrogenerated on the gold sensing platform where the optimal electropolymn. conditions were detd. For this optimized polypyrrole-NTA setup, the simple presence of a graphene layer between the gold and polymer film led to a significant increase of the SPR signal.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXislGjt7o%253D&md5=1e33859e918c99abd4882f6cc4cf06ac
424. 424
  Hu, W.; He, G.; Zhang, H.; Wu, X.; Li, J.; Zhao, Z.; Qiao, Y.; Lu, Z.; Liu, Y.; Li, C. M. Polydopamine-Functionalization of Graphene Oxide to Enable Dual Signal Amplification for Sensitive Surface Plasmon Resonance Imaging Detection of Biomarker Anal. Chem. 2014, 86, 4488– 4493 DOI: 10.1021/ac5003905
  
  424
  Polydopamine-Functionalization of Graphene Oxide to Enable Dual Signal Amplification for Sensitive Surface Plasmon Resonance Imaging Detection of Biomarker
  
  Hu, Weihua; He, Guangli; Zhang, Huanhuan; Wu, Xiaoshuai; Li, Jialin; Zhao, Zhiliang; Qiao, Yan; Lu, Zhisong; Liu, Yang; Li, Chang Ming
  
  Analytical Chemistry (Washington, DC, United States) (2014), 86 (9), 4488-4493CODEN: ANCHAM; ISSN:0003-2700. (American Chemical Society)
  
  Surface plasmon resonance imaging (SPRi) is one of the powerful tools for immunoassays with advantages of label-free, real-time, and high-throughput; however, it often suffers from limited sensitivity. Herein we report a dual signal amplification strategy utilizing polydopamine (PDA) functionalization of reduced graphene oxide (PDA-rGO) nanosheets for sensitive SPRi immunoassay in serum. The PDA-rGO nanosheet is synthesized by oxidative polymn. of dopamine in a gentle alk. soln. in the presence of graphene oxide (GO) sheets and then is antibody-conjugated via a spontaneous reaction between the protein and the PDA component. In the dual amplification mode, the first signal comes from capture of the antibody-conjugated PDA-rGO to form sandwiched immunocomplexes on the SPRi chip, followed by a PDA-induced spontaneous gold reductive deposition on PDA-rGO to further enhance the SPRi signal. The detection limit as low as 500 pg mL-1 is achieved on a nonfouling SPRi chip with high specificity and a wide dynamic range for a model biomarker, carcinoembryonic antigen (CEA) in 10% human serum.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXlsl2qur4%253D&md5=a0a38076d41b5264352de66f7aae3087
425. 425
  Yi, M.; Yang, S.; Peng, Z.; Liu, C.; Li, J.; Zhong, W.; Yang, R.; Tan, W. Two-Photon Graphene Oxide/Aptamer Nanosensing Conjugate for In Vitro or In Vivo Molecular Probing Anal. Chem. 2014, 86, 3548– 3554 DOI: 10.1021/ac5000015
  
  425
  Two-Photon Graphene Oxide/Aptamer Nanosensing Conjugate for In Vitro or In Vivo Molecular Probing
  
  Yi, Mei; Yang, Sheng; Peng, Zanying; Liu, Changhui; Li, Jishan; Zhong, Wenwan; Yang, Ronghua; Tan, Weihong
  
  Analytical Chemistry (Washington, DC, United States) (2014), 86 (7), 3548-3554CODEN: ANCHAM; ISSN:0003-2700. (American Chemical Society)
  
  Two-photon excitation (TPE) with near-IR (NIR) photons as the excitation source have the unique properties of lower tissue autofluorescence and self-absorption, reduced photodamage and photobleaching, higher spatial resoln., and deeper penetration depth (>500 μm). Carbon nanomaterials, for example, graphene oxide (GO), have the advantages of good biocompatibility, efficient transporters into cells, protecting the carried DNA or peptides from enzymic cleavage, and super fluorescence quenching efficiency. By combination of the nanostructured carbon materials with the TPE technique, herein the authors have designed an aptamer-two-photon dye (TPdye)/GO TPE fluorescent nanosensing conjugate for mol. probing in biol. fluids, living cells, and zebrafish. This approach takes advantage of the exceptional quenching capability of GO for the proximate TP dyes and the higher affinity of single-stranded DNA on GO than the aptamer-target complex. Successful in vitro and in vivo detection of ATP was demonstrated with this sensing strategy. The authors' results reveal that the GO/Aptamer-TPdye system not only is a robust, sensitive, and selective sensor for quant. detection of ATP in the complex biol. environment but also can be efficiently delivered into live cells or tissues and act as a "signal-on" in vivo sensor for specific, high-contrast imaging of target biomols. The authors' design provides a methodol. model scheme for development of future carbon nanomaterial-based two-photon fluorescent probes for in vitro or in vivo detn. of biol. or biol. relevant species.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXjsFOltrc%253D&md5=db1133dc5148b04986eab7614b2dad31
426. 426
  Castrignano, S.; Gilardi, G.; Sadeghi, S. J. Human Flavin-Containing Monooxygenase 3 on Graphene Oxide for Drug Metabolism Screening Anal. Chem. 2015, 87, 2974– 2980 DOI: 10.1021/ac504535y
  
  There is no corresponding record for this reference.
427. 427
  Xu, S.; Man, B.; Jiang, S.; Wang, J.; Wei, J.; Xu, S.; Liu, H.; Gao, S.; Liu, H.; Li, Z. Graphene/Cu Nanoparticle Hybrids Fabricated by Chemical Vapor Deposition As Surface-Enhanced Raman Scattering Substrate for Label-Free Detection of Adenosine ACS Appl. Mater. Interfaces 2015, 7, 10977– 10987 DOI: 10.1021/acsami.5b02303
  
  427
  Graphene/Cu Nanoparticle Hybrids Fabricated by Chemical Vapor Deposition As Surface-Enhanced Raman Scattering Substrate for Label-Free Detection of Adenosine
  
  Xu, Shicai; Man, Baoyuan; Jiang, Shouzhen; Wang, Jihua; Wei, Jie; Xu, Shida; Liu, Hanping; Gao, Shoubao; Liu, Huilan; Li, Zhenhua; Li, Hongsheng; Qiu, Hengwei
  
  ACS Applied Materials & Interfaces (2015), 7 (20), 10977-10987CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  We present a graphene/Cu nanoparticle hybrids (G/CuNPs) system as a surface-enhanced Raman scattering (SERS) substrate for adenosine detection. The Cu nanoparticles wrapped by a monolayer graphene shell were directly synthesized on flat quartz by chem. vapor deposition in a mixt. of methane and hydrogen. The G/CuNPs showed an excellent SERS enhancement activity for adenosine. The min. detected concn. of the adenosine in serum was demonstrated as low as 5 nM, and the calibration curve showed a good linear response from 5 to 500 nM. The capability of SERS detection of adenosine in real normal human urine samples based on G/CuNPs was also investigated and the characteristic peaks of adenosine were still recognizable. The reproducible and the ultrasensitive enhanced Raman signals could be due to the presence of an ultrathin graphene layer. The graphene shell was able to enrich and fix the adenosine mols., which could also efficiently maintain chem. and optical stability of G/CuNPs. Based on the G/CuNPs system, the ultrasensitive SERS detection of adenosine in varied matrixes was expected for the practical applications in medicine and biotechnol.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnvFCmsrk%253D&md5=31dcdf4707d8758e8f9c039c8371dd3f
428. 428
  Datta, K. K. R.; Kozak, O.; Ranc, V.; Havrdova, M.; Bourlinos, A. B.; Safarova, K.; Hola, K.; Tomankova, K.; Zoppellaro, G.; Otyepka, M. Quaternized Carbon Dot-Modified Graphene Oxide for Selective Cell Labelling – Controlled Nucleus and Cytoplasm Imaging Chem. Commun. 2014, 50, 10782– 10785 DOI: 10.1039/C4CC02637C
  
  428
  Quaternized carbon dot-modified graphene oxide for selective cell labelling - controlled nucleus and cytoplasm imaging
  
  Datta, K. K. R.; Kozak, O.; Ranc, V.; Havrdova, M.; Bourlinos, A. B.; Safarova, K.; Hola, K.; Tomankova, K.; Zoppellaro, G.; Otyepka, M.; Zboril, R.
  
  Chemical Communications (Cambridge, United Kingdom) (2014), 50 (74), 10782-10785CODEN: CHCOFS; ISSN:1359-7345. (Royal Society of Chemistry)
  
  Cationic quaternized carbon dots (QCDs) and anionic graphene oxide sheets (GO) are combined via non-covalent interactions following a self-assembly pathway to form highly biocompatible and fluorescent hybrid materials. These hybrids act as selective probes with controlled labeling of the cell nucleus or cytoplasm depending on the QCD loading.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVOnurnE&md5=9d543eb037ba17e0810b2458e49f3695
429. 429
  Yin, P. T.; Shah, S.; Chhowalla, M.; Lee, K.-B. Design, Synthesis, and Characterization of Graphene-Nanoparticle Hybrid Materials for Bioapplications Chem. Rev. 2015, 115, 2483– 2531 DOI: 10.1021/cr500537t
  
  429
  Design, Synthesis, and Characterization of Graphene-Nanoparticle Hybrid Materials for Bioapplications
  
  Yin, Perry T.; Shah, Shreyas; Chhowalla, Manish; Lee, Ki-Bum
  
  Chemical Reviews (Washington, DC, United States) (2015), 115 (7), 2483-2531CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)
  
  A review.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXjtVSjs7s%253D&md5=043909061e1bb64f0c5d595077cb25f5
430. 430
  Dikin, D. A.; Stankovich, S.; Zimney, E. J.; Piner, R. D.; Dommett, G. H. B.; Evmenenko, G.; Nguyen, S. T.; Ruoff, R. S. Preparation and Characterization of Graphene Oxide Paper Nature 2007, 448, 457– 460 DOI: 10.1038/nature06016
  
  430
  Preparation and characterization of graphene oxide paper
  
  Dikin, Dmitriy A.; Stankovich, Sasha; Zimney, Eric J.; Piner, Richard D.; Dommett, Geoffrey H. B.; Evmenenko, Guennadi; Nguyen, SonBinh T.; Ruoff, Rodney S.
  
  Nature (London, United Kingdom) (2007), 448 (7152), 457-460CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)
  
  The prepn. and characterization of graphite (graphene) oxide paper, a free-standing carbon-based membrane material made by flow-directed assembly of individual graphite oxide sheets, was reported. This new material outperforms many other paper-like materials in stiffness and strength. Its combination of macroscopic flexibility and stiffness is a result of a unique interlocking-tile arrangement of the nanoscale graphene oxide sheets.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXotFajurc%253D&md5=a777fe03851c7da3d3331b87e53e9e2f
431. 431
  Markovic, Z. M.; Harhaji-Trajkovic, L. M.; Todorovic-Markovic, B. M.; Kepic, D. P.; Arsikin, K. M.; Jovanovic, S. P.; Pantovic, A. C.; Dramicanin, M. D.; Trajkovic, V. S. In Vitro Comparison of the Photothermal Anticancer Activity of Graphene Nanoparticles and Carbon Nanotubes Biomaterials 2011, 32, 1121– 1129 DOI: 10.1016/j.biomaterials.2010.10.030
  
  431
  In vitro comparison of the photothermal anticancer activity of graphene nanoparticles and carbon nanotubes
  
  Markovic Zoran M; Harhaji-Trajkovic Ljubica M; Todorovic-Markovic Biljana M; Kepic Dejan P; Arsikin Katarina M; Jovanovic Svetlana P; Pantovic Aleksandar C; Dramicanin Miroslav D; Trajkovic Vladimir S
  
  Biomaterials (2011), 32 (4), 1121-9 ISSN:.
  
  The present study compared the photothermal anticancer activity of near-infrared (NIR)-excited graphene nanoparticles and carbon nanotubes (CNT). Despite lower NIR-absorbing capacity, suspension of polyvinylpyrrolidone-coated graphene sheets exposed to NIR radiation (808 nm, 2 W/cm(2)) generated more heat than DNA or sodium dodecylbenzenesulfonate-solubilized single-wall CNT under the same conditions. Accordingly, graphene nanoparticles performed significantly better than CNT in inducing photothermal death of U251 human glioma cells in vitro. The superior photothermal sensitivity of graphene sheets could be largely explained by their better dispersivity, which has been supported by a simple calculation taking into account thermodynamic, optical and geometrical properties of the two type of carbon nanoparticles. The mechanisms of graphene-mediated photothermal killing of cancer cells apparently involved oxidative stress and mitochondrial membrane depolarization resulting in mixed apoptotic and necrotic cell death characterized by caspase activation/DNA fragmentation and cell membrane damage, respectively.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3cbps1Khtg%253D%253D&md5=580788bb0a8c3d1789eb91988c3ddb0d
432. 432
  Bitounis, D.; Ali-Boucetta, H.; Hong, B. H.; Min, D.-H.; Kostarelos, K. Prospects and Challenges of Graphene in Biomedical Applications Adv. Mater. 2013, 25, 2258– 2268 DOI: 10.1002/adma.201203700
  
  432
  Prospects and Challenges of Graphene in Biomedical Applications
  
  Bitounis, Dimitrios; Ali-Boucetta, Hanene; Hong, Byung Hee; Min, Dal-Hee; Kostarelos, Kostas
  
  Advanced Materials (Weinheim, Germany) (2013), 25 (16), 2258-2268CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A review. Graphene materials have entered a phase of maturity in their development that is characterized by their explorative utilization in various types of applications and fields from electronics to biomedicine. Herein, we describe the recent advances made with graphene-related materials in the biomedical field and the challenges facing these exciting new tools both in terms of biol. activity and toxicol. profiling in vitro and in vivo. Graphene materials today have mainly been explored as components of biosensors and for construction of matrixes in tissue engineering. Their antimicrobial activity and their capacity to act as drug delivery platforms have also been reported, however, not as coherently. This report will attempt to offer some perspective as to which areas of biomedical applications can expect graphene-related materials to constitute a tool offering improved functionality and previously unavailable options.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXktFWmtL4%253D&md5=ba4c3e140c5b2d9ed9f2aec4fef327f2
433. 433
  Feng, L.; Wu, L.; Qu, X. New Horizons for Diagnostics and Therapeutic Applications of Graphene and Graphene Oxide Adv. Mater. 2013, 25, 168– 186 DOI: 10.1002/adma.201203229
  
  433
  New Horizons for Diagnostics and Therapeutic Applications of Graphene and Graphene Oxide
  
  Feng, Lingyan; Wu, Li; Qu, Xiaogang
  
  Advanced Materials (Weinheim, Germany) (2013), 25 (2), 168-186CODEN: ADVMEW; ISSN:0935-9648. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A review. Graphene, a one-atom-thick two-dimensional (2D) layer of sp2-bonded carbon, has received worldwide attention owing to its extraordinary phys. and chem. properties. Recently, great efforts have been devoted to explore potential applications of graphene and its oxide in life science, esp. in disease-related diagnostics, near-IR (NIR) phototherapy and imaging. Here we will introduce recent advances and new horizons in this area, and focus on the rising progress on NIR photothermal therapy for cancer and Alzheimer's disease (AD), human telomerase detection, stem cell proliferation and differentiation on graphene substrate, diagnosis of cancer cell and related biomarkers, drug/nucleotide/peptide delivery and cell imaging, which have not been comprehensively reviewed. We hope to provide an outlook to the applications of graphene and its oxide, esp. on the new horizons in this field, and inspire broader interests across various disciplines.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XhslSku7rI&md5=748900b5a2700207a8c74c9e4ada990f
434. 434
  Robinson, J. T.; Tabakman, S. M.; Liang, Y.; Wang, H.; Casalongue, H. S.; Daniel, V.; Dai, H. Ultrasmall Reduced Graphene Oxide with High Near-Infrared Absorbance for Photothermal Therapy J. Am. Chem. Soc. 2011, 133, 6825– 6831 DOI: 10.1021/ja2010175
  
  434
  Ultrasmall Reduced Graphene Oxide with High Near-Infrared Absorbance for Photothermal Therapy
  
  Robinson, Joshua T.; Tabakman, Scott M.; Liang, Yongye; Wang, Hailiang; Sanchez Casalongue, Hernan; Vinh, Daniel; Dai, Hongjie
  
  Journal of the American Chemical Society (2011), 133 (17), 6825-6831CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  We developed nanosized, reduced graphene oxide (nano-rGO) sheets with high near-IR (NIR) light absorbance and biocompatibility for potential photothermal therapy. The single-layered nano-rGO sheets were ∼20 nm in av. lateral dimension, functionalized noncovalently by amphiphilic PEGylated polymer chains to render stability in biol. solns. and exhibited 6-fold higher NIR absorption than nonreduced, covalently PEGylated nano-GO. Attaching a targeting peptide bearing the Arg-Gly-Asp (RGD) motif to nano-rGO afforded selective cellular uptake in U87MG cancer cells and highly effective photoablation of cells in vitro. In the absence of any NIR irradn., nano-rGO exhibited little toxicity in vitro at concns. well above the doses needed for photothermal heating. This work established nano-rGO as a novel photothermal agent due to its small size, high photothermal efficiency, and low cost as compared to other NIR photothermal agents including gold nanomaterials and carbon nanotubes.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXksVeitb4%253D&md5=17a058f16c7b12f35d999923fcd7ff59
435. 435
  Jung, H. S.; Kong, W. H.; Sung, D. K.; Lee, M.-Y.; Beack, S. E.; Keum, D. H.; Kim, K. S.; Yun, S. H.; Hahn, S. K. Nanographene Oxide-Hyaluronic Acid Conjugate for Photothermal Ablation Therapy of Skin Cancer ACS Nano 2014, 8, 260– 268 DOI: 10.1021/nn405383a
  
  435
  Nanographene Oxide-Hyaluronic Acid Conjugate for Photothermal Ablation Therapy of Skin Cancer
  
  Jung, Ho Sang; Kong, Won Ho; Sung, Dong Kyung; Lee, Min-Young; Beack, Song Eun; Keum, Do Hee; Kim, Ki Su; Yun, Seok Hyun; Hahn, Sei Kwang
  
  ACS Nano (2014), 8 (1), 260-268CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Melanoma skin cancer is one of the most dangerous skin cancers and the main cause of skin-cancer-related mortality. Hyaluronic acid (HA) has been used as an effective transdermal delivery carrier of chem. drugs and biopharmaceuticals. In this work, a nanographene oxide-HA conjugate (NGO-HA) was synthesized for photothermal ablation therapy of melanoma skin cancer using a near-IR (NIR) laser. Confocal microscopy and ex vivo bioimaging clearly visualized the remarkable transdermal delivery of NGO-HA to tumor tissues in the skin of mice, which might be ascribed to highly expressed HA receptors and relatively leaky structures around tumor tissues, enabling the enhanced permeation and retention of nanoparticles. The NIR irradn. resulted in complete ablation of tumor tissues with no recurrence of tumorigenesis. The antitumor effect was confirmed by ELISA for caspase-3 activity and histol. and immuno-histochem. analyses with TUNEL assay for tumor apoptosis. Taken together, we could confirm the feasibility of transdermal NGO-HA for photothermal ablation therapy of melanoma skin cancers.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhvVWqtQ%253D%253D&md5=9512decbc7cef1787fc5228aa637325d
436. 436
  Liu, J.; Jiang, X.; Xu, L.; Wang, X.; Hennink, W. E.; Zhuo, R. Novel Reduction-Responsive Cross-Linked Polyethylenimine Derivatives by Click Chemistry for Nonviral Gene Delivery Bioconjugate Chem. 2010, 21, 1827– 1835 DOI: 10.1021/bc100191r
  
  436
  Novel Reduction-Responsive Cross-Linked Polyethylenimine Derivatives by Click Chemistry for Nonviral Gene Delivery
  
  Liu, Jia; Jiang, Xulin; Xu, Li; Wang, Xianmiao; Hennink, Wim E.; Zhuo, Renxi
  
  Bioconjugate Chemistry (2010), 21 (10), 1827-1835CODEN: BCCHES; ISSN:1043-1802. (American Chemical Society)
  
  Novel reducible disulfide-contg. crosslinked polyethylenimines (PEI-SS-CLs) were synthesized via click chem. and evaluated as nonviral gene delivery vectors. First, about four azide pendant groups were introduced into a low-mol.-wt. (LMW) PEI (1.8 kDa) to get an azide-terminated PEI. Then, click reaction between a disulfide-contg. dialkyne crosslinker and the azide functionalized LMW PEI resulted in a high-mol.-wt. disulfide-contg. crosslinked PEI composed of LMW constitute via a reducible crosslinker. The synthesized polymers were characterized by 1H NMR, FTIR, and size-exclusion chromatog. (SEC). It was shown that the obtained disulfide-contg. crosslinked PEIs were able to condense plasmid DNA into pos. charged nanoparticles. The degrdn. of the disulfide crosslinked polymers PEI-SS-CLs induced by DTT was confirmed by a gel retardation assay and SEC anal. In vitro expts. revealed that the reducible PEI-SS-CLs were less cytotoxic and more effective in gene transfection (in both the presence and absence of serum) than the control nondegradable 25-kDa PEI. This study demonstrates that a reducibly degradable cationic polymer composed of LMW PEI crosslinked via a disulfide-contg. linker possesses both higher gene transfection efficiency and lower cytotoxicity than PEI (25 kDa). These polymers are therefore attractive candidates for further in vivo evaluations.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtFehurzE&md5=c920ada0d4aba1a2ab694624bc3d1d7c
437. 437
  Ma, N.; Li, Y.; Xu, H.; Wang, Z.; Zhang, X. Dual Redox Responsive Assemblies Formed from Diselenide Block Copolymers J. Am. Chem. Soc. 2010, 132, 442– 443 DOI: 10.1021/ja908124g
  
  437
  Dual Redox Responsive Assemblies Formed from Diselenide Block Copolymers
  
  Ma, Ning; Li, Ying; Xu, Huaping; Wang, Zhiqiang; Zhang, Xi
  
  Journal of the American Chemical Society (2010), 132 (2), 442-443CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)
  
  A block copolymer with diselenide bonds in the polymer backbone was reported. This block copolymer was capable of forming micellar aggregates that were responsive to redox stimuli. Compared with other redox responsive aggregates, this type of diselenide-contg. block copolymer aggregates could be responsive to both oxidants and reductants even in a soln. with a very low concn. under mild conditions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhsFOrtrnJ&md5=fd796a6ece09a94910768265ae07cf8e
438. 438
  Yang, X.; Zhao, N.; Xu, F.-J. Biocleavable Graphene Oxide Based-Nanohybrids Synthesized via ATRP for Gene/Drug Delivery Nanoscale 2014, 6, 6141– 6150 DOI: 10.1039/c4nr00907j
  
  438
  Biocleavable graphene oxide based-nanohybrids synthesized via ATRP for gene/drug delivery
  
  Yang, Xinchao; Zhao, Nana; Xu, Fu-Jian
  
  Nanoscale (2014), 6 (11), 6141-6150CODEN: NANOHL; ISSN:2040-3372. (Royal Society of Chemistry)
  
  Graphene oxide (GO) was proven to be promising in many biomedical fields due to its biocompatibility, unique conjugated structure, easily tunable surface functionalization and facile synthesis. In this work, a flexible 2-step method was first developed to introduce the atom transfer radical polymn. (ATRP) initiation sites contg. disulfide bonds onto GO surfaces. Surface-initiated ATRP of (2-dimethyl amino)ethyl methacrylate (DMAEMA) was then employed to tailor the GO surfaces in a well-controlled manner, producing a series of org.-inorg. hybrids (termed as SS-GPDs) for highly efficient gene delivery. Under reducible conditions, the PDMAEMA side chains can be readily cleavable from the GO backbones, benefiting the resultant gene delivery process. Moreover, due to the conjugated structure of the graphene basal plane, SS-GPD can attach and absorb arom., water insol. drugs, such as 10-hydroxycamptothecin (CPT), producing SS-GPD-CPT. The MTT assay and the simultaneous double-staining procedure revealed that SS-GPD-CPT possessed a high potency of killing cancer cells in vitro. With a high aq. soly. and coulombic interaction with cell membrane, SS-GPDs may have great potential in gene/drug delivery fields.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXotFCiurY%253D&md5=d51196882c66daecde3165318af315d6
439. 439
  Sherlock, S. P.; Tabakman, S. M.; Xie, L.; Dai, H. Photothermally Enhanced Drug Delivery by Ultrasmall Multifunctional FeCo/Graphitic Shell Nanocrystals ACS Nano 2011, 5, 1505– 1512 DOI: 10.1021/nn103415x
  
  439
  Photothermally Enhanced Drug Delivery by Ultrasmall Multifunctional FeCo/Graphitic Shell Nanocrystals
  
  Sherlock, Sarah P.; Tabakman, Scott M.; Xie, Liming; Dai, Hongjie
  
  ACS Nano (2011), 5 (2), 1505-1512CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  FeCo/graphitic carbon shell (FeCo/GC) nanocrystals (∼4-5 nm in diam.) with ultrahigh magnetization are synthesized, functionalized, and developed into multifunctional biocompatible materials. We demonstrate the ability of this material to serve as an integrated system for combined drug delivery, near-IR (NIR) photothermal therapy, and magnetic resonance imaging (MRI) in vitro. We show highly efficient loading of doxorubicin (DOX) by π-stacking on the graphitic shell to afford FeCo/GC-DOX complexes and pH sensitive DOX release from the particles. We observe enhanced intracellular drug delivery by FeCo/GC-DOX under 20 min of NIR laser (808 nm) induced hyperthermia to 43 °C, resulting in a significant increase of FeCo/GC-DOX toxicity toward breast cancer cells. The synergistic cancer cell killing by FeCo/GC-DOX drug delivery under photothermal heating is due to a ∼two-fold enhancement of cancer cell uptake of FeCo/GC-DOX complex and the increased DOX toxicity under the 43 °C hyperthermic condition. The combination of synergistic NIR photothermally enhanced drug delivery and MRI with the FeCo/GC nanocrystals could lead to a powerful multimodal system for biomedical detection and therapy.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtlCktr0%253D&md5=ca973caede159ffd6c51b34de6c5ba51
440. 440
  Dembereldorj, U.; Kim, M.; Kim, S.; Ganbold, E.-O.; Lee, S. Y.; Joe, S.-W. A Spatiotemporal Anticancer Drug Release Platform of PEGylated Graphene Oxide Triggered by Glutathione InVitro and In Vivo J. Mater. Chem. 2012, 22, 23845– 23851 DOI: 10.1039/c2jm34853e
  
  There is no corresponding record for this reference.
441. 441
  Kiyomiya, K.; Matsuo, S.; Kurebe, M. Mechanism of Specific Nuclear Transport of Adriamycin: The Mode of Nuclear Translocation of Adriamycin-Proteasome Complex Cancer Res. 2001, 61, 2467– 2471
  
  441
  Mechanism of specific nuclear transport of adriamycin: the mode of nuclear translocation of adriamycin-proteasome complex
  
  Kiyomiya, Ken-Ichi; Matsuo, Saburou; Kurebe, Masaru
  
  Cancer Research (2001), 61 (6), 2467-2471CODEN: CNREA8; ISSN:0008-5472. (American Association for Cancer Research)
  
  Adriamycin (ADM), an anthracycline anticancer agent, is selectively stored in the nuclei of a variety of proliferating cells, but the precise mechanism of specific nuclear transport of ADM is not well known. Recently, the authors demonstrated that ADM shows high binding affinity to the cytoplasmic proteasomes of L1210 mouse leukemia cells and that taken up ADM by the cells selectively binds to proteasomes. Nuclear targeting of proteasome in proliferating cells may be mediated by the nuclear localization signals that are found in several of the α-type subunits of the 20S proteasome. To confirm nuclear transport of the ADM-proteasome complex, the authors synthesized a photoactive ADM analog, N-(p-azidobenzoyl)-ADM, and generated a photoaffinity-labeled proteasome complex. The 26S proteasome purified from the cytosol of L1210 cells had a high affinity to N-(p-azidobenzoyl)-ADM. SDS-PAGE anal. of the photoaffinity-labeled proteasome showed that low mol. wt. bands (∼21-31 kDa) of 20S proteasome had the highest photoaffinity. The photoaffinity-labeled proteasome was distributed in the cytoplasm and nuclei of digitonin-permeabilized L1210 and B-16 mouse melanoma cells in the presence of the cytosolic fraction and ATP. The rate of nuclear translocation of the proteasome was low in the absence of ATP. These results suggest that the proteasome is a specific translocator of ADM from the cytoplasm to the nucleus and that 20S proteasome components are the dominant ADM-binding sites. The nuclear transport of ADM-proteasome complex is regulated by an ATP-dependent nuclear pore-mediated mechanism.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXisVSlu7s%253D&md5=1be75211fa74f5bc633f4bc81ece2b43
442. 442
  Ochs, M.; Carregal-Romero, S.; Rejman, J.; Braeckmans, K.; De Smedt, S. C.; Parak, W. J. Light-Addressable Capsules as Caged Compound Matrix for Controlled Triggering of Cytosolic Reactions Angew. Chem., Int. Ed. 2013, 52, 695– 699 DOI: 10.1002/anie.201206696
  
  442
  Light-Addressable Capsules as Caged Compound Matrix for Controlled Triggering of Cytosolic Reactions
  
  Ochs, Markus; Carregal-Romero, Susana; Rejman, Joanna; Braeckmans, Kevin; De Smedt, Stefaan C.; Parak, Wolfgang J.
  
  Angewandte Chemie, International Edition (2013), 52 (2), 695-699CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  Multifunctional capsules are well-suited for in vitro delivery of cargo inside cells; technol. has advanced to a point at which these capsules could be a helpful tool for controlled multifunctional in vitro delivery. A large no. of capsules can be taken up by cells in vitro without causing acute cytotoxicity, even for capsules with large sizes of around 5 μm. The loading of cells can be specifically directed by incorporating magnetic NPs in the wall of the capsules. This is possible since magnetic field gradients, which are created by positioning a magnet in a flow channel system, trap the capsules close to the magnet. Capsules with different cargo can be directed by magnetic field gradients to specific regions of a cell culture. Our approach allows light-controlled release of a much larger class of mols. and also subsequent release of different mols. Moreover, the technique to open the capsules is applied on individual capsules, thereby permitting sequential opening of different capsules within one cell. Local disruption of the capsule walls also leads to (transient) permeability of the membrane of the lysosomes in which the illuminated capsules are located. Here, we demonstrate that this approach can be employed to orchestrate intracellular reactions.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhs1Ogs77M&md5=00e794eb5e9863fe331da6c45238e110
443. 443
  Kim, H.; Lee, D.; Kim, J.; Kim, T.-I.; Kim, W. J. Photothermally Triggered Cytosolic Drug Delivery via Endosome Disruption Using a Functionalized Reduced Graphene Oxide ACS Nano 2013, 7, 6735– 6746 DOI: 10.1021/nn403096s
  
  443
  Photothermally Triggered Cytosolic Drug Delivery via Endosome Disruption Using a Functionalized Reduced Graphene Oxide
  
  Kim, Hyunwoo; Lee, Duhwan; Kim, Jinhwan; Kim, Tae-il; Kim, Won Jong
  
  ACS Nano (2013), 7 (8), 6735-6746CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
  
  Graphene oxide has unique physiochem. properties, showing great potential in biomedical applications. In the present work, functionalized reduced graphene oxide (PEG-BPEI-rGO) has been developed as a nanotemplate for photothermally triggered cytosolic drug delivery by inducing endosomal disruption and subsequent drug release. PEG-BPEI-rGO has the ability to load a greater amt. of doxorubicin (DOX) than unreduced PEG-BPEI-GO via π-π and hydrophobic interactions, showing high water stability. Loaded DOX could be efficiently released by glutathione (GSH) and the photothermal effect of irradiated near IR (NIR) in test tubes as well as in cells. Importantly, PEG-BPEI-rGO/DOX complex was found to escape from endosomes after cellular uptake by photothermally induced endosomal disruption and the proton sponge effect, followed by GSH-induced DOX release into the cytosol. Finally, it was concluded that a greater cancer cell death efficacy was obsd. in PEG-BPEI-rGO/DOX complex-treated cells with NIR irradn. than those with no irradn. This study demonstrated the development of the potential of a PEG-BPEI-rGO nanocarrier by photothermally triggered cytosolic drug delivery via endosomal disruption.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhtVGqsLjJ&md5=192f3a742f31a723c22a34e7fbe4ba5e
444. 444
  Yan, L.; Chang, Y.-N.; Yin, W.; Tian, G.; Zhou, G. L.; Liu, X.; Xing, G.; Zhao, L.; Gu, Z.; Zhao, Y. On-Demand Generation of Singlet Oxygen from a Smart Graphene Complex for the Photodynamic Treatment of Cancer Cells Biomater. Sci. 2014, 2, 1412– 1418 DOI: 10.1039/C4BM00143E
  
  444
  On-demand generation of singlet oxygen from a smart graphene complex for the photodynamic treatment of cancer cells
  
  Yan, Liang; Chang, Ya-Nan; Yin, Wenyan; Tian, Gan; Zhou, Liangjun; Liu, Xiaodong; Xing, Gengmei; Zhao, Lina; Gu, Zhanjun; Zhao, Yuliang
  
  Biomaterials Science (2014), 2 (10), 1412-1418CODEN: BSICCH; ISSN:2047-4849. (Royal Society of Chemistry)
  
  Graphene oxide (GO) has been proven to be a highly efficient long-range quencher for various fluorescence processes, which intrinsically work through a photophys. mechanism similar to that of singlet oxygen generation (SOG). Under our hypothesis that GO may be capable of quenching the SOG process, here we design and synthesize a novel nanocomplex consisting of GO, a photosensitizer and an aptamer. We demonstrate that GO is an ideal SOG controller, which can reversibly quench and recover SOG depending on the interaction intensity between GO and a photosensitizer. Addnl., it can simultaneously act as a carrier for the efficient loading and delivery of the photosensitizers to cancer cells. Thus, during the delivery process, SOG of the nanocomplex can be completely inhibited by the quenching capacity of the GO even though there is light present; however, when the nanocomplex enters into cancer cells where target mols. are present, SOG is triggered by a target binding event and singlet oxygen is reversibly released from the nanocomplex, ultimately inducing significant cell death in the presence of light. This proof-of-concept study provides a new chem. strategy for creating a highly selective photodynamic therapy with low toxicity, using hydrophilic GO-based systems.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtV2qurzF&md5=9df13d8c868ee8dac046d0842a5531af
445. 445
  Dong, H.; Dai, W.; Ju, H.; Lu, H.; Wang, S.; Xu, L.; Zhou, S.-F.; Zhang, Y.; Zhang, X. Multifunctional Poly(L-lactide)-Polyethylene Glycol-Grafted Graphene Quantum Dots for Intracellular MicroRNA Imaging and Combined Specific-Gene-Targeting Agents Delivery for Improved Therapeutics ACS Appl. Mater. Interfaces 2015, 7, 11015– 11023 DOI: 10.1021/acsami.5b02803
  
  445
  Multifunctional Poly(L-lactide)-Polyethylene Glycol-Grafted Graphene Quantum Dots for Intracellular MicroRNA Imaging and Combined Specific-Gene-Targeting Agents Delivery for Improved Therapeutics
  
  Dong, Haifeng; Dai, Wenhao; Ju, Huangxian; Lu, Huiting; Wang, Shiyan; Xu, Liping; Zhou, Shu-Feng; Zhang, Yue; Zhang, Xueji
  
  ACS Applied Materials & Interfaces (2015), 7 (20), 11015-11023CODEN: AAMICK; ISSN:1944-8244. (American Chemical Society)
  
  Photoluminescent (PL) graphene quantum dots (GQDs) with large surface area and superior mech. flexibility exhibit fascinating optical and electronic properties and possess great promising applications in biomedical engineering. Here, a multifunctional nanocomposite of poly(L-lactide) (PLA) and polyethylene glycol (PEG)-grafted GQDs (f-GQDs) was proposed for simultaneous intracellular microRNAs (miRNAs) imaging anal. and combined gene delivery for enhanced therapeutic efficiency. The functionalization of GQDs with PEG and PLA imparts the nanocomposite with super physiol. stability and stable photoluminescence over a broad pH range, which is vital for cell imaging. Cell expts. demonstrate the f-GQDs excellent biocompatibility, lower cytotoxicity, and protective properties. Using the HeLa cell as a model, we found the f-GQDs effectively delivered a miRNA probe for intracellular miRNA imaging anal. and regulation. Notably, the large surface of GQDs was capable of simultaneous adsorption of agents targeting miRNA-21 and survivin, resp. The combined conjugation of miRNA-21-targeting and survivin-targeting agents induced better inhibition of cancer cell growth and more apoptosis of cancer cells, compared with conjugation of agents targeting miRNA-21 or survivin alone. These findings highlight the promise of the highly versatile multifunctional nanocomposite in biomedical application of intracellular mols. anal. and clin. gene therapeutics.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXnslGitLs%253D&md5=463d7abeeef5b70efa9d4d78c6139ecb
446. 446
  Bianco, A. Graphene: Safe or Toxic? The Two Faces of the Medal Angew. Chem., Int. Ed. 2013, 52, 4986– 4997 DOI: 10.1002/anie.201209099
  
  446
  Graphene: Safe or Toxic? The Two Faces of the Medal
  
  Bianco, Alberto
  
  Angewandte Chemie, International Edition (2013), 52 (19), 4986-4997CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)
  
  A review. Graphene is considered the future revolutionary material. For its development, it is of fundamental importance to evaluate the safety profile and the impact on health. Graphene is part of a bigger family which has been identified as the graphene family nanomaterials (GFNs). Clarifying the existence of multiple graphene forms allows better understanding the differences between the components and eventually correlating their biol. effects to the physicochem. characteristics of each structure. Some in vitro and in vivo studies clearly showed no particular risks, while others have indicated that GFNs might become health hazards. This Minireview critically discusses the recent studies on the toxicity of GFNs to provide some perspective on the possible risks to their future development in materials and biomedical sciences.
  
  >> More from SciFinder ^®
  https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXlsl2jtrk%253D&md5=4f293b4b7482a9468c792ae44746e9ee

PDF [ 47MB]

All Types

Noncovalent Functionalization of Graphene and Graphene Oxide for Energy Materials, Biosensing, Catalytic, and Biomedical Applications

Article Views

Altmetric

Citations

Abstract

SPECIAL ISSUE

1 Introduction

Figure 1

Figure 2

Figure 3

Figure 4

2 Noncovalent Interactions of Graphene and Graphene Oxide

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

3 Driving Forces for Noncovalent Functionalization of Graphene and Graphene Oxide

3.1 π–π Interactions

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

3.2 van der Waals, Ionic Interactions, and Hydrogen Bonding

Figure 26

4 Noncovalently Functionalizing Agents of Graphene and Graphene Oxide

4.1 Functionalization with Polymers

Figure 27

Figure 28

Figure 29

Figure 30

4.2 Functionalization with Biomolecules

Figure 31

Figure 32

Figure 33

Figure 34

Figure 35

4.3 Functionalization with Drugs

Figure 36

Figure 37

Figure 38

4.4 Functionalization toward 3D Superstructures

Figure 39

Figure 40

Figure 41

4.5 Functionalization with Carbon Nanoallotropes

Figure 42

Figure 43

Figure 44

Figure 45

Figure 46

4.6 Functionalization with 2D Graphene Analogues

Figure 47

Figure 48

Figure 49

Figure 50

Figure 51

4.7 Functionalization with Nanostructures

4.7.1 Synthetic Methods toward Graphene/Nanostructure Hybrids

Figure 52

Figure 53

4.7.2 Decoration of Graphene and Graphene Oxide with Nanostructures for Catalytic Applications

Figure 54

Figure 55

Figure 56

Figure 57

4.7.3 Decoration of Graphene and Graphene Oxide with Nanostructures for Application in Lithium-Ion Batteries