Ni-MOF-74-Derived NiS/Cd _0.7 Zn _0.3 S Boosts Photocatalytic Benzyl Alcohol Oxidation Coupled with H ₂ Evolution

Rationally loading a highly dispersed cocatalyst onto a photocatalyst greatly enhances photocatalytic performance. In this study, Ni-MOF-74 acts as a slow-release source of Ni2+ to synthesize NiS/Cd0.7Zn0.3S (NiS/CZS) via a one-pot method. The gradual release of trace Ni2+ ensures the uniform dispersion and deposition of NiS on CZS. Compared with Ni(NO3)2-derived NiS-CZS and pure CZS, the NiS/CZS composite exhibits markedly improved performance in visible-light-driven benzyl alcohol (BA) oxidation coupled with hydrogen evolution. After 3 h of irradiation, the optimized 12% NiS/CZS achieves 69.5% BA conversion, 18.2 times that of the Ni(NO3)2-derived sample and 31 times that of pure CZS. This improvement arises from the uniform NiS deposition, which enhances the interaction between NiS and CZS, increases interfacial contact, shortens the electron migration distance, and suppresses charge recombination. In situ DRIFTS and EPR analyses unveil the complete pathway of intermediate formation and transformation. This work presents a controllable strategy for uniform cocatalyst deposition, offering an effective approach to boost photocatalytic efficiency.