Regulating on photocatalytic overall water splitting performance of gallium thiophosphate based on transition metal doping: A first-principles study

Abstract

Overall water splitting to produce hydrogen with photocatalyst is an effective strategy to solve the energy crisis. In this work, the photocatalytic properties of the two-dimensional (2D) gallium thiophosphate (GaPS4) are investigated systematically. The results show that the transition metal (TM) doping reduces the energy band gap of GaPS4 and enhances the optical absorption significantly in the visible light range. Besides, based on some screen rules from 20 kinds of TM doping systems, the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) overpotential of Pt@VS1-GaPS4 are found to be 0.41 V and 0.15 V, respectively. Furthermore, the band edges of Pt@VS1-GaPS4 meet the requirement of the redox potential of water under a large pH value range. Our work proves TM doping is an excellent way to tune the band edge and catalytic activity at the same time, which provides good guidance for experimentalists in the future to prepare the GaPS4-based photocatalyst.