Efficient photocatalytic hydrogen evolution based on a Z-scheme 2D LaVO4/2D Mo-doped SV-ZnIn2S4 heterojunction

The purposeful design and construction of two-dimensional (2D) semiconductor heterojunctions offers a promising avenue for achieving efficient photocatalytic activity. However, it remains a challenge to enable efficient charge migration at the interface. In this study, we successfully prepare 2D ultrathin Z-scheme heterojunctions based on LaVO4 and ZnIn2S4 (ZIS) with excellent contact interfaces and robust internal electric fields through oxygen vacancy and sulfur vacancy (S-V) induction and molybdenum atom doping. Surface defects facilitate the formation of 2D heterojunctions. The optimized heterojunction exhibits outstanding photocatalytic hydrogen evolution performance (8.67 mmol g(-1) h(-1)) with an apparent quantum efficiency (lambda > 420 nm) of 30.57%. Mechanistic analysis and theoretical calculations demonstrate that the molybdenum atoms promote interfacial charge transfer and enhance the internal electric field between the LaVO4 and S-V-MZIS interfaces, ultimately leading to the formation of a Z-scheme charge transfer channel. This work establishes an engineering design model for atomic-scale 2D interfaces with modulated charge transfer.