Highly Selective, Defect-Induced Photocatalytic CO2 Reduction to Acetaldehyde by the Nb-Doped TiO2 Nanotube Array under Simulated Solar Illumination

Xinzhu Qian; Weiyi Yang; Shuang Gao; Jun Xiao; Swastik Basu; Anthony Yoshimura; Yunfeng Shi; Vincent Meunier; Qi Li

doi:10.1021/acsami.0c17174

Highly Selective, Defect-Induced Photocatalytic CO₂ Reduction to Acetaldehyde by the Nb-Doped TiO₂ Nanotube Array under Simulated Solar Illumination

ACS Appl Mater Interfaces. 2020 Dec 16;12(50):55982-55993. doi: 10.1021/acsami.0c17174. Epub 2020 Dec 6.

Authors

Xinzhu Qian^{1

2}, Weiyi Yang³, Shuang Gao³, Jun Xiao¹, Swastik Basu⁴, Anthony Yoshimura⁵, Yunfeng Shi⁴, Vincent Meunier^{4

5}, Qi Li³

Affiliations

¹ Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China.
² School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, P. R. China.
³ Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, P. R. China.
⁴ Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
⁵ Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.

PMID: 33283493
DOI: 10.1021/acsami.0c17174

Abstract

The adsorption and activation of CO₂ molecules on the surface of photocatalysts are critical steps to realize efficient solar energy-induced CO₂ conversion to valuable chemicals. In this work, a defect engineering approach of a high-valence cation Nb-doping into TiO₂ was developed, which effectively enhanced the adsorption and activation of CO₂ molecules on the Nb-doped TiO₂ surface. A highly ordered Nb-doped TiO₂ nanotube array was prepared by anodization of the Ti-Nb alloy foil and subsequent annealing at 550 °C in air for 2 h for its crystallization. Our sample showed a superior photocatalytic CO₂ reduction performance under simulated solar illumination. The main CO₂ reduction product was a higher-energy compound of acetaldehyde, which could be easily transported and stored and used to produce various key chemicals as intermediates. The acetaldehyde production rate was over ∼500 μmol·g^-1·h^-1 with good stability for repeated long-time uses, and it also demonstrated a superior product selectivity to acetaldehyde of over 99%. Our work reveals that the Nb-doped TiO₂ nanotube array could be a promising candidate with high efficiency and good product selectivity for the photocatalytic CO₂ reduction with solar energy.

Keywords: CO2 adsorption and activation; Nb-doped TiO2 nanotube array; acetaldehyde; photocatalytic CO2 reduction; simulated solar illumination.