Construction of SrTiO3/ZnxCd1−xS S-scheme heterojunction composites as efficient bifunctional photocatalysts for HCHO degradation and hydrogen production

Abstract

A new SrTiO₃/Zn_xCd_1−xS S-scheme heterojunction (STO/ZCS-y, y = 0.1–0.9) was constructed, in which SrTiO₃ nanomaterials were prepared by electrostatic spinning and high-temperature calcination and then successfully composited with Zn_xCd_1−xS by a hydrothermal method. As anticipated, the STO/ZCS-0.3 composite demonstrated an optimal formaldehyde (HCHO) degradation rate of 82.2%, along with a hydrogen yield of 2566.15 μmol g⁻¹ h⁻¹, which is a significant improvement over previously reported STO-based photocatalysts. STO/ZCS exhibited excellent photogenerated carrier separation along the S-scheme electron transfer pathway in the catalytic process. Furthermore, the S-scheme heterojunction enabled substantial suppression of the photocorrosion of ZCS by inhibiting charge transfer, thereby enhancing the chemical stability of the photocatalyst. This study offers significant insights for the preparation of efficient S-scheme heterojunctions for photocatalytic removal of HCHO and generation of H₂.