A Z-scheme heterojunction constructed by ZnO/CeVO4 for highly active photocatalytic hydrogen production

Abstract

Photocatalytic hydrogen production is one of the most promising ways to obtain sustainable hydrogen energy. However, it is constrained by low energy conversion efficiency, which is due to the fast recombination of photogenerated electrons and holes, the low utilization rate of the visible light of the solar spectrum, and the severe photo corrosion of semiconductor photocatalyst. The construction of semiconductor heterojunction is not only beneficial to the separation of photogenerated carriers in photocatalysts, but also effective to broaden the range of light harvest by introducing narrow bandgap semiconductors. In this paper, a heterojunction photocatalyst ZnO/CeVO₄ was obtained by simple mild physical method. The Z-scheme heterostructure of ZnO/CeVO₄ is conducive to the strong electron interaction, the enlarged light trapping range, the promoted separation and migration of photo carriers, and the high redox properties. Compared with the pure ZnO and CeVO₄ catalysts, the photocatalytic efficiency of ZnO/CeVO₄ is higher, and the optimal hydrogen production rate reaches 1289 μmol/(g·h). This work affords a simple mild method to construct a Z-scheme CeVO₄ based photocatalysts, which show high active photocatalytic H₂ production performance.