Subsurface oxygen defects electronically interacting with active sites on In2O3 for enhanced photothermocatalytic CO2 reduction

Weiqin Wei; Zhen Wei; Ruizhe Li; Zhenhua Li; Run Shi; Shuxin Ouyang; Yuhang Qi; David Lee Philips; Hong Yuan

doi:10.1038/s41467-022-30958-5

Subsurface oxygen defects electronically interacting with active sites on In₂O₃ for enhanced photothermocatalytic CO₂ reduction

Nat Commun. 2022 Jun 9;13(1):3199. doi: 10.1038/s41467-022-30958-5.

Authors

Weiqin Wei¹, Zhen Wei², Ruizhe Li¹, Zhenhua Li³, Run Shi³, Shuxin Ouyang⁴, Yuhang Qi⁵, David Lee Philips², Hong Yuan¹

Affiliations

¹ Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China.
² Department of Chemistry, University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
³ Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, China.
⁴ Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, 430079, China. oysx@mail.ccnu.edu.cn.
⁵ Chemical Engineering Institute, Hebei University of Technology, 300131, Tianjin, China.

Abstract

Oxygen defects play an important role in many catalytic reactions. Increasing surface oxygen defects can be done through reduction treatment. However, excessive reduction blocks electron channels and deactivates the catalyst surface due to electron-trapped effects by subsurface oxygen defects. How to effectively extract electrons from subsurface oxygen defects which cannot directly interact with reactants is challenging and remains elusive. Here, we report a metallic In-embedded In₂O₃ nanoflake catalyst over which the turnover frequency of CO₂ reduction into CO increases by a factor of 866 (7615 h^-1) and 376 (2990 h^-1) at the same light intensity and reaction temperature, respectively, compared to In₂O₃. Under electron-delocalization effect of O-In-(O)V_o-In-In structural units at the interface, the electrons in the subsurface oxygen defects are extracted and gather at surface active sites. This improves the electronic coupling with CO₂ and stabilizes intermediate. The study opens up new insights for exquisite electronic manipulation of oxygen defects.