Synergistic incorporation of MoS2 cocatalyst into ZnIn2S4 nanoflower architectures for efficient photocatalytic H2 production and selective benzyl alcohol oxidation

Abstract

Construction of efficient catalysts for photocatalytic hydrogen evolution and selective oxidation of coupled organics is an effective way to obtain clean, renewable fuels and high-value chemicals using photogenerated electrons and holes. Here, we successfully introduced the co-catalyst MoS₂ into the ZnIn₂S₄ nanoflower sphere matrix, which can effectively separate electrons and holes, suppress electron-hole recombination, and realize the synergistic coupling of photocatalytic H₂ evolution and selective oxidation of benzyl alcohol. By tuning the MoS₂ loading, we optimized the active site density and charge transfer efficiency of the ZnIn₂S₄ catalyst, thereby enhancing its H₂ evolution performance. It was also found that ZnIn₂S₄ exhibited the highest catalytic activity in the benzyl alcohol oxidation reaction with the addition of 3 wt% MoS₂ and achieved the oxidation of benzyl alcohol to benzaldehyde. In addition, we investigated the effects of different sacrificial reagents on the catalytic performance, and the results further verified the universality and feasibility of the catalytic system. Notably, the catalyst demonstrated excellent photocatalytic degradation performance, achieving removal efficiencies of 98 %, 77 %, 76 %, and 70 % for rhodamine B (RhB), tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC), respectively. This work elucidates the critical role of MoS₂ as a cocatalyst in enhancing charge separation and surface reaction kinetics, providing a viable strategy for designing dual-functional photocatalysts for simultaneous H₂ evolution and organic transformations.