Solar-Driven Highly Effective Biomass-Derived Alcohols C–C Coupling Integrated with H<sub>2</sub> Production by CdS Quantum Dots Modified Zn<sub>2</sub>In<sub>2</sub>S<sub>5</sub> Nanosheets
Zongyi Huang, Pengfei Sun, Huizhen Zhang, Haikun Zhang, Shuhong Zhang, Zhou Chen, Xiaodong Yi, Shunji Xie
Abstract
The integration of solar-driven H 2 evolution with the selective conversion of biomass-derived alcohols into value-added chemicals has gained significant attention for full use of electrons and holes. We develop a dual-functional photocatalyst for highly selective oxidation of the C α –H bond of benzyl alcohol to C–C coupled products (hydrobenzoin and deoxybenzoin), in cooperation with H 2 evolution, using point-to-face interface engineering by decorating CdS quantum dots on Zn 2 In 2 S 5 nanosheets (CdS QDs/Zn 2 In 2 S 5 NS). The CdS QDs/Zn 2 In 2 S 5 NS exhibit a high H 2 evolution rate of 13 mmol g –1 h –1 and C–C coupled products formation rate of 10.8 mmol g –1 h –1 with 96.3% selectivity. Benzyl alcohol conversion achieves 91% with an 89% yield of C–C coupled products in gram-scale. The introduction of CdS enhances the interfacial contact, facilitating the efficient spatial separation of photogenerated electron–hole pairs and providing active sites for H 2 evolution. In situ characterization and DFT calculation reveal that the carbon-centered radical •CH(OH)C 6 H 5, generated by abstracting the C α –H bond of benzyl alcohol, is the reactive intermediate in the photocatalytic C–C coupled process.