Sulfur-vacancy-enriched ZnIn2S4 mediates efficient charge transfer for hydrogen evolution from lignocellulose photoreforming

The rapid recombination of photogenerated electron-hole pairs and the slow electron transfer rate at the catalyst-solution interface seriously limit hydrogen production from α-cellulose photoreforming. Herein, a sulfur-vacancy-enriched ZnIn 2 S 4 (S VH -ZIS) photocatalyst was prepared, and Pt nanoclusters were grown on its surface by in situ photodeposition. Sulfur vacancies coupling Pt nanoclusters optimize the electron transport channel and realize efficient electron migration from α-cellulose to H + through the photocatalyst. The construction of sulfur vacancies promoted the formation of ·OH and enhanced the adsorption and activation of glucose, which significantly improved the oxidation of α-cellulose and accelerated the oxidation kinetics of α-cellulose. Meanwhile, the sulfur vacancies promote the separation efficiency of photogenerated electron-hole pairs and broaden the absorption wavelength range of light. Pt clusters provide hydrogen evolution reaction sites and achieve spatial separation of oxidation and reduction reaction sites. As a result, the hydrogen yield of α-cellulose photoreforming catalyzed by 0.25 % Pt/S VH -ZIS reached 522.76 μmol/g/h, which was 6.02 times that of 0.25 % Pt/S VL -ZIS (sulfur-vacancy-poor ZIS) and significantly higher than that of most previously reported photocatalysts.