Dual vacancies induced local polarization electric field for high-performance photocatalytic H2 production

Abstract

Charge separation and transfer from bulk to the redox sites of surface limits the photocatalytic process. Herein, we prepared a novel NiSeS cocatalyst with Ni–Se dual vacancies to construct NiSeS/ZnSe heterojunctions. The optimized NiSeS/ZnSe photocatalyst exhibits a high photocatalytic H2-evolution rate of 18.32 mmol g−1 h−1 which is 107.8- and 10.2- fold higher than that of pristine ZnSe and 1% Pt/ZnSe, respectively. A high apparent quantum yield value of 50.77% was achieved at 420 nm. The photocatalytic H2 evolution activity of NiSeS/ZnSe is better than most of the state-of-the-art ZnSe-based photocatalysts. The Ni–Se dual vacancies induce a local polarization electric field, which accelerates the surface charge transfer and reduces the reaction barrier in the photocatalytic process. This work provides a feasible approach to introduce dual vacancies and the surface local polarization over photocatalysts for high-performance photocatalytic H2 production.