Chinese Journal of Catalysis ›› 2025, Vol. 74: 130-143.DOI: 10.1016/S1872-2067(25)64649-3

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Surface oxygen vacancies of BiOBr regulating piezoelectricity for enhancing efficiency and selectivity of photocatalytic CO2 reduction

Cunjun Lia, Jie Heb, Tianle Caib, Xianlei Chena,*(), Hengcong Taoc, Yingtang Zhouc,*(), Mingshan Zhub,*()   

  1. aZhejiang Key Laboratory of Petrochemical Environmental Pollution Control, National Engineering Research Center for Marine Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhoushan 316004, Zhejiang, China
    bGuangdong Key Laboratory of Environmental Pollution and Health, College of Environment and Climate, Jinan University, Guangzhou 511443, Guangdong, China
    cMarine Science and Technology College, Zhejiang Ocean University, Zhoushan 316004, Zhejiang, China
  • Received:2025-01-07 Accepted:2025-02-24 Online:2025-07-18 Published:2025-07-20
  • Contact: *E-mail: zschenxl@163.com (X. Chen), zhouyingtang@zjou.edu.cn (Y. Zhou), zhumingshan@jnu.edu.cn (M. Zhu).
  • Supported by:
    National Natural Science Foundation of China(22322604)

Abstract:

Although defect engineering has been widely used to boost catalytic CO2 photoreduction, the piezoelectric polarized properties induced by structure changes through introducing defects are always ignored. Here we report a new kind of bismuth oxybromide (BiOBr, BOB) with piezoelectric property regulated by oxygen vacancies (OVs). Compared with pure BOB, BOB with OVs (BOB-OV) could enhance photocatalytic CO2 reduction efficiency under the ultrasonic force, achieving durable CO2 reduction process to superior production rates of CO (54.4 µmol g-1 h-1) with a high selectivity (92%). Moderate OVs concentration changed the degree of Bi-Br stretching in the BOB-OV to produce strong dipole moments, which endowed BOB-OV with strong spontaneous piezoelectric polarization ability under external force. Ultrasonic piezoelectric effects were innovatively integrated into the photocatalytic reaction, which not only provided an alternating force field to modulate the spontaneous polarization of BOB-OV, thereby maintaining efficient photogenerated charge separation, but also lowered the reaction energy barrier of CO2 by high stress, ultimately improving CO product selectivity. This study is the first to leverage OVs-induced piezoelectric polarization effects to enhance the performance and product selectivity of photocatalytic CO2 reduction, providing new directions and insights for defect engineering to contribute to photocatalysis.

Key words: BiOBr, Oxygen vacancy, Piezoelectricity, High selectivity, Photocatlytic CO2 reduction