Fabrication of NiB/ZnIn₂S₄ Z-Scheme Heterojunction: Simultaneously Boosts Photocatalytic H₂ Evolution and Selective Oxidation of Benzyl Alcohol

Photocatalytic conversion of biomass-derived compounds into value-added chemicals coupled with hydrogen production presents a promising strategy to address energy and environmental challenges. In this study, a series of NiB/ZnIn2S4 nanocomposites were synthesized via a facile two-step hydrothermal approach. The designed system enables the simultaneous utilization of photoexcited electrons and holes in redox reactions, achieving efficient benzyl alcohol oxidation and hydrogen evolution. The optimized 3%-NiB/ZnIn2S4 nanocomposite demonstrates exceptional photocatalytic performance, exhibiting a hydrogen evolution rate of 7223.2 μmol g–1 h–1 in 1.50 vol % benzyl alcohol solution, representing 2889.3-fold and 4.8-fold enhancements over pristine NiB and ZnIn2S4, respectively. Furthermore, the system maintains robust stability over 14 photocatalytic cycles, achieving 71.7% conversion efficiency and 86.8% selectivity toward benzaldehyde production. The enhanced performance originates from the formation of Z-scheme heterojunctions between NiB and ZnIn2S4, which facilitates efficient charge carrier separation and transport, as evidenced by improved photocurrent response and reduced electrochemical impedance. This work provides valuable insights into the photocatalytic valorization of biomass-derived platform chemicals under visible light irradiation.