In situ construction of Ohmic/Schottky-type MoS2/Sv-ZnIn2S4/Cu(OH)2 dual-junction photocatalysts with enhanced water splitting into hydrogen generation activity

Abstract

Exploring visible-light-driven photocatalytic materials for water splitting is of great significance for achieving green and renewable hydrogen fuel. In this work, MoS₂/S_v-ZnIn₂S₄/Cu(OH)₂ (MS/S_v-ZIS/COH) dual-junction composites for hydrogen generation were constructed by an in situ structure-tailored technique. Based on the in situ decomposition of Cu₃Mo₂O₉ (CMO), the instantaneous formation of the sulfur vacancy (S_v), Ohmic-type MS/S_v-ZIS heterojunction and Schottky-type S_v-ZIS/COH heterojunction not only markedly boosted the carrier separation and quickly expedited the charge transfer, but also efficiently inhibited charge recombination and significantly accelerated the hydrogen reduction dynamics. As a result, such composites exhibited an optimum hydrogen production rate of 11.5 mmol h⁻¹ g⁻¹, which was approximately 4.6 times higher than that of pristine ZIS. This work provides an in situ design method to construct new photocatalytic materials for accelerating the redox dynamics and enhancing the water splitting performance.