Engineered Sulfur Vacancies in Z‐scheme ZnS/TiO ₂ Heterostructure for Dual Photocatalytic Functionality

Abstract The design of heterojunction semiconductor photocatalysts with well‐aligned band edges is crucial for optimizing charge carrier dynamics in photocatalytic water splitting and organic transformations. In this study, a two‐step solvothermal and wet chemical method is employed to synthesize sulfur vacancy (sv)‐rich ZnS nanowires (NWs) with varying proportions of TiO 2 nanoparticles (NPs). Photocatalytic hydrogen evolution study reveals that the optimized sv‐ZT 0.3 heterostructure exhibits a remarkable hydrogen evolution of 35.77 mmol g −1 due to the Z‐scheme charge transfer mechanism significantly outperformed pristine TiO 2 (1.02 mmol g −1 ) and sv‐ZnS NWs (4.77 mmol g −1 ) for a fixed irradiation duration (5 h) with an apparent quantum yield of 25.2% at 366 nm. Sulfur vacancies in ZnS extend the optical absorption, while the heterojunction enhances charge separation, as confirmed by UV–vis and photoluminescence studies. Additionally, sv‐ZT 0.3 achieved 89.1% conversion of benzyl alcohol to benzaldehyde during hydrogen generation. The superior performance of the heterostructure for integrated solar‐driven hydrogen production and selective organic transformations paved the way for advanced photocatalyst development in sustainable energy applications.