Interfacial chemical bond regulating the electronic coupling of ZnIn2S4−x-WO3−x for enhancing the photocatalytic pollutions degradation coupled with hydrogen evolution

Abstract

Constructing Z-scheme heterostructure photocatalysts with a staggered band structure holds great potential to realize synergistic oxidation and reduction reactions. However, the Z-scheme heterostructure with interfacial vacancies significantly disturbs the behaviors of charge transfer and remains a challenging as well as urgent issue to exploit. Here, the ultrathin ZnIn2S4−x-WO3−x Z-scheme heterostructure (ZW) was synthesized via a facile in situ hydrothermal strategy. Experimental results and DFT calculations unveiled that the dual vacancies induced the formation of interfacial bonds. Importantly, the interfacial bonds tremendously modulate the electronic structure of heterostructure for enlarging the built-in electric field and reducing the aggregation effect of charge in the interface vacancies, which contributed to promoting charge transfer through the interface as well as exciton dissociation. Ultimately, the optimized ZW-4 exhibited an exceptional photocatalytic hydrogen evolution performance of 737.75 μmol g−1 h−1 and a pollution degradation rate greater than 99.99% without using any cocatalyst under visible light irradiation. Our work offers a deep insight into the ideal charge migration paths in highly efficient Z-scheme heterojunctions with vacancies.