A novel Bi2WO6/Si heterostructure photocatalyst with Fermi level shift in valence band realizes efficient reduction of CO2 under visible light

Abstract

In this paper, a novel Bi2WO6/Si heterostructure photocatalyst with Fermi level shift in valence band was developed for efficient reduction of CO2 under visible light. The shift of the Fermi level to the valence band can effectively reduce the difficulty of electron holes generation. According to a series of characterizations, it is found that the heterostructure photocatalysts with special branch structure achieve an increase in BET surface area and the photocatalysts’ ability to absorb visible light. In terms of photoelectric performance, the existence of heterojunction in photocatalysts enhances the ability of photo-excited electron-hole pair separation and prolongs the electron lifetime. Among the samples in this paper, WSi1-1 (Bi2WO6:Si = 1:1) reduces CO2 into the only product ethanol, and the ethanol yield reached 402.76 μmol/L. Therefore, the Bi2WO6/Si heterostructure photocatalyst is a low-cost, efficient and promising photocatalyst with broad application prospects.