Efficient Photoredox-Mediated C–C Coupling Organic Synthesis and Hydrogen Production over Engineered Semiconductor Quantum Dots

Abstract

Photocatalytic hydrogen (H 2 ) evolution coupled with selective organic synthesis over semiconductor-based photocatalysts is attractive because the clean H 2 fuel and value-added chemicals can be coproduced at ambient conditions using solar light as the sole energy input. Here, we report the efficient merging catalysis of photoredox-driven dehydrogenative C–C coupling of benzyl alcohol (BA) into hydrobenzoin (HB) and H 2 evolution over the SiO 2 -supported semiconductor CdS quantum dots (QDs) at ambient temperature and pressure. In this system, we utilize the judicious interfacial engineering approach to rationally assemble CdS QDs onto the spherical SiO 2 support by which CdS QDs can recycle the scattered light in the near field of SiO 2 and achieve the significantly enhanced light-harvesting capability and more efficient generation of charge carriers. Consequently, as compared to bare CdS QDs and Pt/SiO 2, the SiO 2 -supported CdS QDs (CdS/SiO 2 ) exhibits distinctly boosted photoredox-catalyzed activity and stability for C–C coupling of BA into HB and H 2 evolution. The underlying origin toward an efficient C–C coupling reaction over CdS/SiO 2 is analyzed accordingly. This work would open a conceptual vista of utilizing a near-field scattering-promoted optical absorption model and nanoscale interfacial assembly method to maneuver the light-capturing property of semiconductor QDs without size alteration for solar fuel production and organic synthesis of fine chemicals.