Visible-light deposition of CrOx cocatalyst on TiO2∶Cr valence regulation for superior photocatalytic CO2 reduction to CH4

• 作者: Jingjing Dong Yuan Kong Heng Cao Zhiyu Wang Zhirong Zhang Lidong Zhang Song Sun Chen Gao Xiaodi Zhu Jun Bao
• 来源期刊: 能源化学
• 年，卷（期）: 2022,（1）
• 页码范围: 103-112
• 页数: 10页
• 语种: 英文

摘要

Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on semiconductors.However,it is prerequisite that the photon energy should be sufficient to excite the host semiconductor.Here,we report a lower-energy irradiation powered deposition strategy for implanting CrOx cocatalyst on TiO2.Excitingly,CrOx-400 implanted under visible-light irradiation significantly promotes the CH4 evolu-tion rate on TiO2 to 8.4 μmol g-1 h-1 with selectivity of 98％ from photocatalytic CO2 reduction,which is 15 times of that on CrOx-200 implanted under UV-visible-light irradiation.Moreover,CrOx-400 is identified to be composed of higher valence Cr species compared to CrOx-200.This valence states regulation of Cr species is indicated to provide more active sites for CO2 adsorption/activation and to modulate the reac-tion mechanism from single Cr site to Cr-Cr dual sites,thus endowing the superior CH4 production.This work demonstrates an alternative strategy for constructing efficient metal oxides cocatalysts on wide bandgap semiconductor.