Graphdiyne (C n H2n−2) based S-scheme heterojunction to promote carrier transfer for efficiently photocatalytic hydrogen evolution

Abstract

Graphdiyne (GDY) is a new carbon allotrope with excellent properties due to its unique structure and highly conjugated system. In this work, GDY/CuMoO4 (CMO)/CuO tandem S-scheme heterojunction was constructed using the cross-coupling method. Among them, CuI is not only used as a coupling catalyst to obtain easily collected GDY, but also as a precursor for more active composite catalysts. 2D GDY provides a substrate for the loading of CMO and CuO, while the highly conjugated system and excellent electrical conductivity allow the composites to form a unique system with strong charge distribution and transport. The step-by-step progressive S-scheme heterojunctions constructed based on the one-step calcination strategy have stronger reducing activity and carrier transfer capability. The intrinsic charge transfer mechanism of the catalyst was investigated by photoelectrochemical characterization and in situ x-ray photoelectron spectroscopy analysis, and the mechanism of the photocatalytic hydrogen production reaction was proposed. This work provides a viable approach for the development of GDY in photocatalysis and the design of S-scheme heterojunctions.