Recent advances in designing ZnIn2S4-based heterostructured photocatalysts for hydrogen evolution

Water and solar energy are inexhaustible on Earth, and thus hydrogen evolution through photocatalytic water splitting taking sunlight as the input energy is an ideal green energy generation technology. As a typical visible-light-responsive photocatalyst, ZnIn2S4 attracted worldwide research attention because of its many advantages for photocatalytic hydrogen evolution (PHE), such as layered structure, simple syntheses, structural stability, environmental friendliness, and suitable electronic band structure. In recent years, constructing ZnIn2S4-based heterostructured photocatalysts has become a research focus for their significantly improved spatial charge carrier separation efficiency and PHE performances. According to the charge carrier transfer/separation mechanisms, heterostructured ZnIn2S4-based photocatalysts are divided into five categories, conventional heterojunctions (type-I and type-II), p-n heterojunction, Z-scheme heterojunction, S-scheme (or Step-scheme) heterojunction, and co-catalyst deposition based heterojunction systems. This article reviews the recent advances in ZnIn2S4-based heterostructured photocatalysts for PHE. Firstly, the central part of this review introduced various ZnIn2S4-based heterojunctions and their PHE application. Secondly, apart from common half-reaction of water-splitting, we expressly introduced overall water splitting, dual-functional and photothermal effect-assisted PHE systems. Then, we briefly presented some identification methods for confirming heterojunction types. Finally, the current states, challenges and perspectives of ZnIn2S4-based heterostructured photocatalysts for PHE are also discussed. This review aims to explore the advantages of diverse ZnIn2S4-based heterostructures, and can provide an insight into designing high-efficiency heterostructured photocatalysts for PHE application.