Selective Photoredox Enabled C–C Coupling of Ethanol over Pt-Modified Zn_0.75Cd_0.25S Catalyst

2,3-Butanediol (2,3-BD) is a high-value chemical with wide applications in pharmaceuticals, polymers, and biofuels. Photocatalytic conversion of ethanol to 2,3-BD offers a promising route for sustainable chemical synthesis as it enhances the economic value of ethanol and reduces reliance on fossil fuels. In this study, we develop an efficient photocatalytic system for selective transformation of ethanol into 2,3-BD using Pt-modified Zn0.75Cd0.25S catalysts (Pt/Zn0.75Cd0.25S), demonstrating superior productivity and selectivity in neat ethanol compared to previous studies. The Pt nanoparticles on Zn0.75Cd0.25S significantly enhance the separation and transfer of charge carriers, thereby improving the photoredox catalytic activity. Moreover, the hydrogen bonding interactions between ethanol molecules and α-hydroxyethyl radical intermediates (•CH(OH)CH3) play a pivotal role in facilitating the C–C coupling reaction, optimizing the selectivity toward 2,3-BD. This work offers valuable insights for the rational design of Pt-modified semiconductor photocatalysts, facilitating the selective transformation of ethanol into value-added chemicals and clean H2 fuel.