Cu 2-x Se Modification onto Monoclinic BiVO 4 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-x Se 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-x Se is larger than that of BiVO4 . Therefore, electrons flow to Cu2-x Se 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 3 wt% Cu2-x Se/BiVO4 composite is 15.8 times than that of pure BiVO4 .