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

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 SiO2-supported semiconductor CdS quantum dots (QDs) at ambient temperature and pressure. In this system, we utilize the judicious interfacial engineering approach to rationally assemble OH CdS QDs onto the spherical SiO2 support by which CdS QDs can recycle the scattered light in the near field of SiO2 and achieve the significantly enhanced light-harvesting capability and more efficient generation of charge carriers. Consequently, as compared to bare CdS QDs and Pt/SiO2, the SiO2-supported CdS QDs (CdS/SiO2) 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/SiO2 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.