Cu₂O/BiVO₄ heterostructures: Synthesis and application in simultaneous photocatalytic oxidation of organic dyes and reduction of Cr(VI) under visible light

We synthesized Cu₂O/BiVO₄ composites by growing Cu₂O nanoparticles on BiVO₄ under mild condition. The optimized composite shows high photocatalytic efficiency in the simultaneous oxidation of organic dyes and reduction of Cr(VI) in neutral media. The XPS results confirm that the Cr(VI) adsorbed on Cu₂O/BiVO₄ was completely reduced to Cr(III). The photocatalyst can be used for the degradation of cationic or anionic dyes as well as a mixture of them under visible light irradiation. The photocatalytic activity of the composite can be ascribed to the heterojunctions between Cu₂O and BiVO₄, which facilitate the separation of photogenerated electrons and holes. The work demonstrates that the as-synthesized Cu₂O/BiVO₄ composite is a promising photocatalyst for the treatment of wastewater that contains organic dyes and Cr(VI) ions.