Mn-S chemical bond mediated Z-scheme photocatalyst boosting efficient H2 evolution with apparent quantum yield exceeding 32% under visible light

Developing a highly effective solar-to-H 2 conversion system is a promising strategy for carbon neutrality. Here, we report a chemically bonded Z-scheme photocatalyst by specifically linking the conduction band site of ZnIn 2 S 4 with the valence band site of Mn 0.3 Cd 0.7 S 1-x . Deviates from the typical van der Waals interactions between two semiconductors, the in-built robust binding force (Mn-S bond) and charge transfer channel facilitates the electron mobility, minimizes detrimental deep charge trapping, and prolongs the active charge lifetime from 983 ps to 4250 ps. The sulfur vacancies in Mn 0.3 Cd 0.7 S 1-x are partially refilled by atoms of the same element in ZnIn 2 S 4 during the in-situ formation of heterojunctions, which promotes and solidates the establishment of interfacial chemical bonds. The optimal photocatalyst achieves a high quantum efficiency of 32.71 % at 420 nm. This study offers a new insight into the development of Z-Scheme heterojunctions via a synergistic approach involving doping, vacancy filling and strong interfacial chemical bonds.