▎ 摘 要
Solar-driven production of hydrogen peroxide (H2O2), as an important industrial chemical oxidant with an extensive range of applications, from oxygen reduction is a sustainable alternative to mainstream anthraquinone oxidation and direct hydrogenation of dioxygen methods. The efficiency of solar to hydrogen peroxide over semiconductor-based photocatalysts is still largely limited by the narrow light absorption to visible light. Here, the authors proposed and demonstrate the proof-of-concept application of light-generated hot electrons in a graphene/semiconductor (exemplified with widely used TiO2) dyad to largely extend visible light spectra up to 800 nm for efficient H2O2 production. The well-designed graphene/semiconductor heterojunction has a rectifying interface with a zero barrier for the hot electron injection, largely boosting excited hot electrons with an average lifetime of approximate to 0.5 ps into charge carriers with a long fluorescent lifetime (4.0 ns) for subsequent H2O2 production. The optimized dyadic photocatalyst can provide an H2O2 yield of 0.67 mm g(-1) h(-1) under visible light irradiation (lambda >= 400 nm), which is 20 times of the state-of-the-art noble-metal-free titanium oxide-based photocatalyst, and even achieves an H2O2 yield of 0.14 mm g(-1) h(-1) upon photoexcitation by near-infrared-region light (approximate to 800 nm).