Exceptionally Robust CuInS₂/ZnS Nanoparticles as Single Component Photocatalysts for H₂ Evolution

In this work, we report water-soluble CuInS 2 /ZnS nanoparticles (NPs) as intrinsic single-component photocatlaysts for light-driven hydrogen generation. In the presence of ascorbic acid (AA), this catalyst can efficiently generate H 2 from water with an exceptionally long lifetime (≫84 h). Mechanistic insight into the catalysis revealed by transient absorption spectroscopy demonstrates that the catalytic cycle initiates by a reductive quenching process through electron transfer from AA to CuInS 2 /ZnS NPs, which is followed by a rate limiting step, i.e., proton reduction from electrons in the conduction band/defect states of the CuInS 2 /ZnS NPs.