In recent years, there have been many studies on photocatalytic water splitting, but there are still few high-efficiency photocatalysts for photocatalytic seawater splitting. In this study, a series of hollow Co sulphide-supported CdS catalyst (H–CoS/CdS) composite photocatalysts were prepared by loading CdS onto the surface of H–CoS, which can be used for efficient H 2 production in pure water and simulated seawater. The heterojunction H–CoS/CdS exhibited H 2 production of 572.4 μmol g −1 (4 h) from simulated seawater, which is 97.7 and 2.96 times those of H–CoS and CdS, respectively. The h-CoS cocatalyst extended the light absorption range of CdS, improved the chemical stability, and significantly enhances the charge separation efficiency. This study provides guidance for the reasonable design of a photocatalytic seawater-based H 2 production catalyst with high efficiency and low cost.
Yilei Li,Qing Zhao,Yang Zhang,Yunchao Li,Louzhen Fan,Fa-tang Li,Xiaohong Li
Photocatalysis has been facing challenging problems especially the inefficient photocarriers transfer at the interfaces. Here, based on K sp difference, we prepare the sequential heterojunction of CoS/CdS/CuS via sequential cation exchange strategy, and propose the concept of "electron-welcome zone", where the point-to-point contact can be formed at the interface, thus providing continuous electron transport channels. HAADF-STEM EDS line test indicates the formation of designed structures, and the p/n junction is confirmed by band structure and Mott-Schottky analysis. Theoretical calculation indicates that CoS reduces the Gibbs free energy of the reaction. TRPL spectra show that the existence of "electron welcome zone" greatly improves the lifetime of electrons. This sequential structure enable the optimal H 2 production rate to reach 123.2 mmol g −1 h −1 with AQE of 45.6%, which is among the highest values of CdS-based photocatalysts. This work opens new way to efficient photogenerated carrier transfer channel for solar-energy conversion.