Defect Engineering Adjusting Graphdiyne/Mn_0.3Cd_0.7S S‐Scheme Heterojunction Interface Charge Arrangement for Efficient Photocatalytic Hydrogen Evolution

Abstract

By implementing surface defect engineering and establishing an efficient electron‐transport pathway, the photocatalytic performance of the catalyst can be significantly enhanced. In this work, the addition amount of thioacetamide is varied to control the vacancy content of Mn0.3Cd0.7S nanorods, resulting in the occurrence of dislocation phenomena. In the results from the hydrogen evolution test, it is demonstrated that Mn0.3Cd0.7S with a specific sulfur vacancy exhibits 17 times higher hydrogen evolution activity to regular Mn0.3Cd0.7S. The Mn0.3Cd0.7S material, featuring a sulfur vacancy, exhibits enhanced electron affinity and significantly improved light‐absorption ability upon combination with graphdiyne to form a dual catalyst, with the lowest electron‐transfer resistance and the most excellent photogenerated electron migration speed. The successful construction of S‐scheme heterojunctions establishes new transmission channels for electron transport, allowing for spatial separation of electrons and holes, allowing more electrons to participate in hydrogen evolution reactions. In addition, in situ X‐ray photoelectron spectroscopy, electron paramagnetic resonance, and density‐functional theory calculations are used to demonstrate the existence of vacancies, the bandgap structure of the material, the distribution of charges after vacancies occur, and possible photocatalytic mechanisms.