Chinese Journal of Catalysis ›› 2024, Vol. 66: 257-267.DOI: 10.1016/S1872-2067(24)60120-8

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Dipole moment regulation by Ni doping ultrathin Bi4O5Br2 for enhancing internal electric field toward efficient photocatalytic conversion of CO2 to CO

Xiaotian Wang, Bo Hu, Yuan Li, Zhixiong Yang, Gaoke Zhang*()   

  1. Hubei Key Laboratory of Mineral Resources Processing and Environment, State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, Hubei, China
  • Received:2024-07-10 Accepted:2024-08-22 Online:2024-11-18 Published:2024-11-10
  • Contact: *E-mail: gkzhang@whut.edu.cn (G. Zhang).
  • Supported by:
    National Natural Science Foundation of China(92163125);Cooperative Research project between the National Natural Science Foundation of China and the Russian Science Foundation(22361132537)

Abstract:

The low efficiency of photogenerated carrier separation, and the poor adsorption and activation ability of CO2 on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO2 reduction. Hence, maximally accelerating the immigration of photogenerated charges d increasing the number of active sites are critical points to boost the overall performance of photocatalytic CO2 reduction. However, it is still huge challenge. In this work, the Ni-doped ultrathin Bi4O5Br2 nanosheets, which was successfully prepared by hydrothermal and ultrasonic chemical stripping methods, exhibited efficient photocatalytic conversion of CO2 to CO. The results of experiments and theoretical calculations indicated that the doped Ni2+ significantly increased the crystal dipole moment of Bi4O5Br2 in y direction (from 0 to 0.096 eÅ), which enhanced the polarized electric field strength inside Bi4O5Br2, and further promoted the immigration of photogenerated carriers. Meanwhile, the ultrathin structure and doped Ni2+ synergistically increased the number of active sites, thereby promoting the adsorption and activation of CO2 molecules, as evidenced by experimental and theoretical results collectively. As result, The CO yield was as high as 26.57 μmol g-1 h-1 for the prepared Ni-doped ultrathin Bi4O5Br2 nanosheets under full spectrum light irradiation, which was 9.48 times that of Bi4O5Br2. Therefore, it is of great scientific significance in this study to explore strategies to promote the separation of photogenerated carriers and enhance the adsorption and activation ability of CO2 on the surface.

Key words: Ni-doped Bi4O5Br2, Ultra-thin nanomaterial, Dipole moment, Polarized electric field, Photocatalytic CO2 reduction