J. Mater. Sci. Technol. ›› 2022, Vol. 123: 234-242.DOI: 10.1016/j.jmst.2022.02.018

• Research Article • Previous Articles     Next Articles

Construction of oxygen vacancy on Bi12O17Cl2 nanosheets by heat-treatment in H2O vapor for photocatalytic NO oxidation

Yi Yang, Yi Zeng, Tongxin Jin, Xiaohu Zhang*(), Huailong Teng*(), Shengyao Wang*(), Hao Chen   

  1. College of Science, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
  • Received:2021-11-20 Revised:2022-02-11 Accepted:2022-02-14 Published:2022-10-01 Online:2022-09-30
  • Contact: Xiaohu Zhang,Huailong Teng,Shengyao Wang
  • About author:thlong@mail.hzau.edu.cn (H. Teng),
    *E-mail addresses: xiaohuzhang@mail.hzau.edu.cn (X. Zhang),
    First author contact:1 These authors contributed equally to this work.

Abstract:

Oxygen-vacancies (OVs) play significant roles in semiconductor-based photocatalysis, such as elevating light absorption property, photogenerated carries separation efficiency, molecular activation, and photocatalytic activity. However, heat-treatment of semiconductors in dangerous H2 atmosphere is usually indispensable for OVs formation. In this work, C-doped Bi12O17Cl2 nanosheets were facially heat-treated in H2O vapor (∼2.3 vol%) mixed with Ar at 300 °C to in-situ introduce OVs by the proposed reactions of C(s) + H2O(g) → CO(g) + H2(g) and H2(g) + OLattice → H2O(g) + OV. The formation of OVs, which was confirmed by electron paramagnetic resonance (EPR), can narrow the band gap, and enhance the photogenerated e-/h+ separation efficiency on Bi12O17Cl2. Moreover, OVs-rich Bi12O17Cl2 nanosheets can facilitate molecular O2 activation and produce more reactive oxygen species (ROS), especially 1O2, which greatly improve the NO to NO3- conversion efficiency with NO removal rate of ∼63% and NO3- production selectivity of ∼92.6 %. The present work will bring new insights into the construction and roles of OVs in semiconductor-based photocatalysis.

Key words: Oxygen-vacancies, H2O vapor, Photocatalytic, NO oxidation, 1O2