ZnIn2S4 synergized with BiVO4 to construct S-scheme heterojunction photocatalysts for highly efficient production of oxygen and benzaldehyde

Abstract

BiVO₄ is a typical oxidative semiconductor, characterized by strong oxidation capability, visible-light response and high activity. Nevertheless, its application is hindered by the rapid recombination of photogenerated carriers, and insufficient reduction capability. To address this issue, ZnIn₂S₄, an efficient reducing semiconductor, was coupled with BiVO₄ to form an S-scheme heterojunction (BVZS) enriched with surface oxygen vacancies. Driven by the S-scheme charge transfer mechanism, the BVZS possesses improved visible-light harvesting, robust redox capability and rapid separation of photogenerated carriers, enabling bi-functional applications in O₂ generation from water splitting, and aerobic benzyl alcohol conversion to produce benzaldehyde (BAD). Under Xenon lamp, the O₂ evolution and BAD yield of the ZnIn₂S₄/BiVO₄ reached 2208.49 µmol g⁻¹ h⁻¹ and 7.40 mmol g⁻¹ h⁻¹, outperforming most of reported ZnIn₂S₄ or BiVO₄-based systems. This work presents a promising strategy for designing bi-functional heterojunction catalysts to achieve water splitting and organic synthesis.