Customizing ZnIn2S4 Photocatalyst by Regulating Sulfur Source for C(sp3)−H Transformation

Harnessing the power of photoredox catalysis for the selective C(sp3)−H activation and oxidation of alkyl aromatics represents a cutting-edge approach to transforming petroleum-derived feedstocks into value-added C(sp3)−C(sp3) coupled chemicals. Herein, we delve into the photocatalytic process that involves the selective dehydrocoupling of ethylbenzene (EB) to access 2,3-diphenylbutane (DPB) alongside H2, employing three sulfur source-varied ZnIn2S4 (denoted as ZIS-x) catalysts. ZIS-TAA, with thioacetamide (TAA) as sulfur source, exhibits exceptional photocatalytic efficiency for DPB and H2 production. The results show the deficiency of charge carrier recombination centers in defect-poor ZIS-TAA is conducive to the separation of photogenerated charge. Additionally, the larger specific surface area and more surface functional groups provide abundant sites for reactant adsorption and activation, facilitating redox process aided by an ideal band-edge structure. This work illustrates a simple and cost-effective paradigm for designing semiconductor-based photocatalysts with tailored surface properties to enhance the efficiency of target cooperative photoredox reaction.