1. Beijing Normal Univ, Coll Chem, Key Lab Theoret & Computat Photochem, Minist Educ, Beijing 100875, Peoples R China
2. Hebei Univ Sci & Technol, Coll Sci, Hebei Prov Key Lab Photoelect Control Surface & I, Shijiazhuang 050018, Hebei, Peoples R China
折叠
Abstract
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.
Key words
Sequential heterojunction/Electron-welcome zone/Built-in electric field/Sequential ion exchange/Photocatalytic hydrogen evolution
NSTL
Elsevier