Single-Atom Phosphorus Defects Decorated CoP Cocatalyst Boosts Photocatalytic Hydrogen Generation Performance of Cd0.5 Zn0.5 S by Directed Separating the Photogenerated Carriers.

Design and preparation of an efficient and nonprecious cocatalysts, with structural features and functionality necessary for improving photocatalytic performance of semiconductors, remain a formidable challenge until now. Herein, for the first time, a novel CoP cocatalyst with single-atom phosphorus vacancies defects (CoP-Vp ) is synthesized and coupled with Cd0.5 Zn0.5 S to build CoP-Vp @Cd0.5 Zn0.5 S (CoP-Vp @CZS) heterojunctions photocatalysts via a liquid phase corrosion method following by an in suit growth process. The nanohybrids deliver an attractive photocatalytic hydrogen production activity of 2.05 mmol h-1 30 mg-1 under visible-light irradiation, which is 14.66 times higher than that of the pristine ZCS samples. As expected, CoP-Vp further enhances the charge-separation efficiency of ZCS, in addition to the improvement of the electron transfer efficiency, which is confirmed by the ultrafast spectroscopies. Mechanism studies based on density functional theory calculations verify that Co atoms adjacent with single-atom Vp play the key role in translation, rotation, and transformation of electrons for H2 O reduction. This scalable strategy focusing defect engineering provides a new insight into designing the highly active cocatalysts to boost the photocatalytic application.