Constructed 2D sandwich-like layer WO3/Ti3C2/ZnIn2S4 Z-scheme heterojunction by chemical bond for effective photocatalytic hydrogen production.

Photocatalytic water-splitting has gained significant global attention in recent years. However, identifying effective photocatalysts remains challenging due to the rapid recombination of photoinduced charge carriers. In this study, two-dimensional (2D) sandwich-like layer WO₃/Ti₃C₂/ZnIn₂S₄ photocatalysts were successfully fabricated using a simple anaerobic solvothermal process. The 2D Z-scheme heterojunction enhances rapid charge transport via TiS or TiOW bonds, serving as efficient charge transfer channels and minimizing the distance for interfacial photocarrier transfer. Consequently, the hydrogen production rate of 20 % WO₃/Ti₃C₂/ZnIn₂S₄ composite reaches 7.39 mmol·g^-1·h^-1, which is 3.5 and 7.1 times higher than that of 20 % Ti₃C₂/ZnIn₂S₄ and pure ZnIn₂S_4, respectively. Furthermore, the hydrogen production rate of 20 % WO₃/Ti₃C₂/ZnIn₂S₄ composite reaches 2.54 mmol·g^-1·h^-1 without the use of sacrificial agents. This work paves the way for designing 2D sandwich-like Z-scheme heterostructures through interfacial chemical bonds.