Realization of Photocatalytic Overall Water Splitting Under Visible Light by Surface Phosphorization

Abstract

It has been proved that the energy bandgap of semiconductors can be narrowed by introducing disorder in the surface layers. However, the way to disorder the surface’s atomic arrangement is unitary only through hydrogenation reduction. In this work, we first propose a conceptually new approach to realize visible-light absorption by surface phosphorization, which can upraise the VBM and keep the CBM at the same time. Specifically, the surface phosphorization for BixY1-xVO4 was successfully prepared by annealing them with a slight NaH2PO2 under N2 atmosphere. After this treatment, the obtained BixY1-xVO4 showed a distinct trailing absorption extending from 550 nm to 800 nm. The treatment of surface phosphorization on BixY1-xVO4 not only improves photocatalytic activity but also realizes visible light photocatalytic overall water splitting. Moreover, it is demonstrated that this surface phosphorization is universal for Bi-based composite oxides.

Keywords: Bi-based composite oxides, overall water splitting, surface phosphorization, Photocatalysis, visible-light