Cu2-xSe Modification onto Monoclinic BiVO4 for Enhanced Photocatalytic Activity Under Visible Light

The rapid recombination of electron-hole pairs in BiVO4 has limited its performance as a photocatalysis. In this paper, BiVO4 is combined with Cu2-xSe semiconductor to slow down the recombination process, and thus improve its photocatalytic activity. This is enabled by careful band structure design. The work function of Cu2-xSe is larger than that of BiVO4. Therefore, electrons flow to Cu2-xSe from BiVO4 after the composition. Accordingly, an inner field could be built, which facilitates the separation of electrons and holes. The experimental result shows that the photocatalytic efficiency of the 3wt% Cu2-xSe/BiVO4 composite is 15.8 times than that of pure BiVO4.