Cu(2−x)Se Modification onto Monoclinic BiVO(4) for Enhanced Photocatalytic Activity Under Visible Light

The rapid recombination of electron-hole pairs in BiVO(4) has limited its performance as a photocatalysis. In this paper, BiVO(4) is combined with Cu(2−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 Cu(2−x)Se is larger than that of BiVO(4). Therefore, electrons flow to Cu(2−x)Se from BiVO(4) 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% Cu(2−x)Se/BiVO(4) composite is 15.8 times than that of pure BiVO(4).