Potassium and Boron Co-Doping of g-C<sub>3</sub>N<sub>4</sub> Tuned CO<sub>2</sub> Reduction Mechanism for Enhanced Photocatalytic Performance: A First-Principles Investigation
Gang Fu,
Wenqing Zhen,
Hongyi Wang,
Xin Zhou,
Li Yang,
Jiaxu Zhang
Affiliations
Gang Fu
Xinjiang Key Laboratory of Clean Conversion and High Value Utilization of Biomass Resources, School of Chemistry and Chemical Engineering, Yili Normal University, Yining 835000, China
Wenqing Zhen
State Key Laboratory of Urban Water Resource and Environment, MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
Hongyi Wang
State Key Laboratory of Urban Water Resource and Environment, MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
Xin Zhou
State Key Laboratory of Urban Water Resource and Environment, MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
Li Yang
Xinjiang Key Laboratory of Clean Conversion and High Value Utilization of Biomass Resources, School of Chemistry and Chemical Engineering, Yili Normal University, Yining 835000, China
Jiaxu Zhang
Xinjiang Key Laboratory of Clean Conversion and High Value Utilization of Biomass Resources, School of Chemistry and Chemical Engineering, Yili Normal University, Yining 835000, China
Graphitic phase carbon nitride (g-C3N4, abbreviated as CN) can be used as a photocatalyst to reduce the concentration of atmospheric carbon dioxide. However, there is still potential for improvement in the small band gap and carrier migration properties of intrinsic materials. K-B co-doped CN (KBCN) was investigated as a promising photocatalyst for carbon dioxide reduction via the Density Functional Theory (DFT) method. The electronic and optical properties of CN and KBCN indicate that doping K and B can improve the catalytic performance of CN by promoting charge migration and separation. In terms of the Gibbs free energy change, the CO2 reduction reaction catalysed by KBCN results in CH3OH, and its optimal pathway is CO2 → *CO2 → *COOH → CO → *OCH → HCHO → *OCH3 → CH3OH. Compared with CN, the doping elements K and B shift the rate-determining step from CO2 → *CO2 to *CO2 → *COOH. The K and B elements co-doping tuned the charge distribution between the catalyst and the adsorbate and reduced the Gibbs free energy of the rate-determining step from 1.571 to 0.861 eV, suggesting that the CO2 reduction activity of KBCN is superior to that of CN. Our work provides useful insights for the design of metallic–nonmetallic co-doped CN for photocatalytic CO2 reduction (CO2PR) reactions.
