Journal of Energy Chemistry ›› 2022, Vol. 69 ›› Issue (6): 348-355.DOI: 10.1016/j.jechem.2022.01.015

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Self-template-oriented synthesis of lead-free perovskite Cs3Bi2I9 nanosheets for boosting photocatalysis of CO2 reduction over Z-scheme heterojunction Cs3Bi2I9/CeO2

You-Xiang Fenga, Guang-Xing Donga, Ke Sua, Zhao-Lei Liua, Wen Zhanga,*, Min Zhanga,b,*, Tong-Bu Lua   

  1. aMOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China;
    bTianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384, China
  • Received:2021-11-10 Revised:2021-12-31 Accepted:2022-01-09 Online:2022-06-15 Published:2022-10-25
  • Contact: * E-mail addresses: zhangwen@email.tjut.edu.cn (W. Zhang), zm2016@email.tjut. edu.cn (M. Zhang).

Abstract: Lead halide perovskite (LHP) nanocrystals have been intensely studied as photocatalysts for artificial pho-tosynthesis in recent years. However, the toxicity of lead in LHP seriously limits their potential for wide-spread applications. Herein, we first present the synthesis of 2D lead-free halide perovskite (Cs3Bi2I9) nanosheets with self-template-oriented method, in which BiOI/Bi2O2.7 nanosheets were used as the tem-plate and Bi ion source simultaneously. Through facile electrostatic self-assembly strategy, a Z-scheme heterojunction composed of Cs3Bi2I9 nanosheets and CeO2 nanosheets (Cs3Bi2I9/CeO2-3:1) was con-structed as photocatalyst for the photo-reduction of CO2 coupled with the oxidation of H2O. Due to the matching energy levels and the close interfacial contact between Cs3Bi2I9 and CeO2 nanosheets, the sep-aration efficiency of the photogenerated carriers in Cs3Bi2I9/CeO2-3:1 composite was significantly improved. Consequently, the environment-friendly halide perovskite heterojunction Cs3Bi2I9/CeO2-3:1 presents impressive photocatalytic activity for the reduction of CO2 to CH4 and CO with an electron con-sumption yield of 877.04 lmol g—1, which is over 7 and 15 times higher than those of pristine Cs3Bi2I9 and CeO2 nanosheets, exceeding the yield of other reported bismuth-based perovskite for photocatalytic CO2 reduction.

Key words: Lead-free perovskite, Z-scheme heterojunction, Cs3Bi2I9 nanosheets, Photocatalytic CO2 reduction, H2O oxidation