In-situ construction of sequential heterostructured CoS/CdS/CuS for building electron-welcome zone to enhance solar-to-hydrogen conversion

Photocatalysis has been facing challenging problems especially the inefficient photocarriers transfer at the interfaces. Here, based on Ksp 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 photo generated carrier transfer channel for solar-energy conversion.

Automated summary

This study prepared a sequential heterojunction of CoS/CdS/CuS via sequential cation exchange strategy, forming an electron-welcome zone to optimize electron transport channels and enhance photocatalytic hydrogen production. The results confirmed the significance of this sequential structure for solar energy conversion.