In situ formation of ZnS/Ni3S2 with hybrid nanostructure of MoS2/ZnO on graphene/nickel foam for enhanced photoelectrochemical activity

This article presents a novel method for in situ forming ZnS/Ni3S2 with a hybrid nanostructure MoS2/ZnO directly on a graphene/nickel foam (NF) by chemical vapor deposition and a hydrothermal process. The MoS2/ ZnO/graphene/NF (MZGN) shows exceptional performance and achieves a remarkable photocurrent density, surpassing NF, ZnO/NF, and ZGN by approximately 29, 7, and 3 times, respectively. The MZGN photoanode exhibits a maximum applied bias photon-to-current efficiency of 5.5% at 0.09 V versus Ag/AgCl, corresponding to a 1.5-fold increase over the ZGN photoanode. These enhancements result from MoS2's visible-light absorption, in situ generation of ZnS and Ni3S2, and close interfacial contact between semiconductors, which allows for efficient charge separation and transport. The inclusion of graphene as a co-catalyst improves the PEC performance and significantly reduces the onset potential. The charge transfer mechanism was proposed to comprehensively understand the process of PEC activity in semiconductors and co-catalysts. These findings contribute to the advancement of PEC technology and provide important insights for the design and development of photoanodes for improved PEC activities, contributing to the progress of sustainable hydrogen production and renewable energy utilization.