Efficient photocatalytic hydrogen evolution based on a Z-scheme 2D LaVO4/2D Mo-doped SV-ZnIn2S4 heterojunction†
Abstract
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 (SV) 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 (λ > 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 SV-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.