Graphene-decorated 3D BiVO4 photocatalysts with controlled size and shape for efficient visible-light-induced photocatalytic performance

Graphene decorated 3D double-layer half-open flower BiVO4 composite (BVO-GS) was prepared via a facile solvothermal route. It was found that the size of the 3D BiVO4 could be reduced from 4.5 µm to 2 µm with the addition of graphene oxide (GO). And the transportation and separation of the photo-generated electrons-holes were also significantly improved. Photocatalytic performances of BiVO4 and BVO-GS have been evaluated by removing gaseous NO and RhB in liquid under visible light (VL) irradiation, where BVO-GS sample displayed enhanced photoactivity. The conversion of NO (~400 ppm) was about 60% and the RhB degradation ratio was about 90% for BVO-GS under VL irradiation. The boosted performance was attributed to the synthesized effect of size, shape and high photo-generated electrons-holes. The present study reveals that the role of graphene is not only a capping agent to controlling the size, but also a catalyst promoter for the photocatalytic performance.