One-Step Hydrothermal Synthesis of 2D Hexagonal Nanoplates of α-Fe₂O₃/Graphene Composites with Enhanced Photocatalytic Activity

There has been significant progress in the field of semiconductor photocatalysis, but it is still a challenge to fabricate low-cost and high-activity photocatalysts because of safety issues and non-secondary pollution to the environment. Here, 2D hexagonal nanoplates of α-Fe₂O₃/graphene composites with relatively good distribution are synthesized for the first time using a simple, one-step, template-free, hydrothermal method that achieves the effective reduction of the graphene oxide (GO) to graphene and intimate and large contact interfaces of the α-Fe₂O₃ nanoplates with graphene. The α-Fe₂O₃/graphene composites showed significantly enhancement in the photocatalytic activity compared with the pure α-Fe₂O₃ nanoplates. At an optimal ratio of 5 wt% graphene, 98% of Rhodamine (RhB) is decomposed with 20 min of irradiation, and the rate constant of the composites is almost four times higher than that of pure α-Fe₂O₃ nanoplates. The decisive factors in improving the photocatalytic performance are the intimate and large contact interfaces between 2D hexagonal α-Fe₂O₃ nanoplates and graphene, in addition to the high electron withdrawing/storing ability and the highconductivity of reduced graphene oxide (RGO) formed during the hydrothermal reaction. The effective charge transfer from α-Fe₂O₃ nanoplates to graphene sheets is demonstrated by the significant weakening of photoluminescence in α-Fe₂O₃/graphene composites.