Fabrication of S‐Scheme GDY‐CuI/ZnWO4 Photocatalyst to Promote Electron Transfer for Enhanced Photocatalytic H2 Evolution

Abstract

AbstractThe exceptional performance of graphdiyne (GDY) in photocatalysis for hydrogen evolution attracts much attention, but the narrow band gap of GDY complicates the effective realization of the dissociation between photogenerated charges and photogenerated holes. In this study, GDY‐CuI is synthesized by cross‐coupling method, and the wide bandgap ZnWO4 is introduced into it by low‐temperature mixing, which effectively constructed the GDY‐CuI/ZW‐50 double S‐scheme heterojunction. The optimized GDY‐CuI/ZW‐50 catalyst photocatalytic hydrogen evolution performance reached 308.61 µmol after 5 h of visible light irradiation, which is 12.86 and 6.56 times than that of GDY‐CuI and ZnWO4, respectively. The improved efficiency of hydrogen evolution is attributed to the formation of a double S‐scheme heterojunction between GDY, CuI, and ZnWO4 and an internal electric field, which promotes charge transfer, reduces the complexation rate of photogenerated electrons, and enhances the redox capacity of photogenerated charges. A combination of photoelectrochemical analysis, in situ X‐ray photoelectron spectroscopy (In situ XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT) results revealed the electron transfer mechanism. This work will provide new ideas for the design and preparation of GDY‐based photocatalysts.