Visible Light-Driven α-Fe2O3 Nanorod/Graphene/BiV1-xMoxO4 Core/Shell Heterojunction Array for Efficient Photoelectrochemical Water Splitting

We report the design, synthesis, and characterization of a novel heterojunction array of alpha-Fe2O3/graphene/BiV1-xMoxO4 core/shell nanorod for photoelectrochemical water splitting. The heterojunction array was prepared by hydrothermal deposition of alpha-Fe2O3 nanorods onto Ti substrate, with subsequent coating of graphene interlayer and BiV1-xMoxO4 shell by photocatalytic reduction and a spin-coating approach, respectively. The heterojunction yielded a pronounced photocurrent density of similar to 1.97 mA/cm(2) at 1.0 V vs Ag/AgCl and a high photoconversion efficiency of similar to 0.53% at -0.04 V vs Ag/AgCl under the irradiation of a Xe lamp. The improved photoelectrochemical properties benefited from (1) the enhanced light absorption due to behavior of the window effect between the alpha-Fe2O3 cores and BiV1-xMoxO4 shells, and (2) the improved separation of photogenerated carriers at the alpha-Fe2O3 nanorod/graphene/BiV1-xMoO4 interfaces. Our results demonstrate the advantages of the novel graphene-mediated core/shell heterojunction array and provide a valuable insight for the further development of such materials.