Graphdiyne(C_(n)H_(2n-2)based CuI-GDY/ZnAl LDH double S-scheme heterojunction proved with in situ XPS for efficient photocatalytic hydrogen production

The photocatalytic performance can be significantly improved by constructing suitable heterojunction photocatalysts.It is well known that graphdiyne possesses a unique conjugated carbon network nanostructure,which gives it ample active sites on its surface and facilitates the reduction of protons.In this study,a unique new double S-scheme heterojunction photocatalyst was constructed by simple self-assembly of GDY prepared via organic synthesis methods and ZnAl-LDH.According to the study,an internal electric field controlling the transfer direction of the electron hole is formed between the interface of CuI-GDY and ZnAl-LDH,which broadens the light absorption range of the catalyst and improves the redox ability of the photocatalytic system.CuI-GDY and ZnAl-LDH are tightly bound together,which helps to separate the photogenerated carriers while preserving the strong reduction electrons in the GDY conduction band and the strong oxidation holes in the ZnAl-LDH valence band so that they can fully participate in the redox reaction.The charge-transfer paths on the S-scheme heterojunction interface were analyzed by in situ irradiation XPS.This work provides an effective strategy for the construction of double S-scheme heterojunction photocatalysts.