Crystal-Plane Effects of CeO2{110} and CeO2{100} on Photocatalytic CO2 Reduction: Synergistic Interactions of Oxygen Defects and Hydroxyl Groups

• Published in: ACS sustainable chemistry & engineering Vol. 8; no. 38; pp. 14397 - 14406
• Main Authors: Zhu, Chengzhang, Wei, Xiaoqian, Li, Wanqin, Pu, Yu, Sun, Jingfang, Tang, Kunlin, Wan, Haiqin, Ge, Chengyan, Zou, Weixin, Dong, Lin
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28.09.2020
• Subjects: Hydroxyl group; Lewis basicity/acidity; CeO2{110} and CeO2{100}; Oxygen defect; Photocatalytic CO2 reduction
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.0c04205

For photocatalytic CO2 reduction, the synergistic effect of Lewis acidity and basicity on CO2 activation is worthy of study. On the basis of a large number of oxygen defects (Lewis acidity) and hydroxyl groups (Lewis basicity) on the CeO2 surface, CeO2{110} and CeO2{100} crystal planes were developed to investigate the synergistic effect on photocatalytic CO2 reduction. Compared with CeO2{100}, the surface oxygen defects were prone to generate on CeO2{110}, leading to available visible light absorption and faster photogenerated charge transfer. The experimental results and DFT calculations showed that the OH species on the CeO2{110} surface were richer and provided more electron density, i.e., Lewis basicity. Furthermore, the possible adsorption intermediate was investigated and suggested that CeO2{110} was more beneficial for the adsorption and activation of CO2 reactant than CeO2{100}, resulting in generation of carboxylate species and •CO2 – radicals, instead of carbonate. Under the control of surface Lewis acidity and basicity, CeO2{110} had superior photocatalytic performance of CO2 reduction than the {100} plane.