Chinese Journal of Catalysis ›› 2020, Vol. 41 ›› Issue (1): 161-169.DOI: 10.1016/S1872-2067(19)63391-7

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Fabrication of Z-scheme MoO3/Bi2O4 heterojunction photocatalyst with enhanced photocatalytic performance under visible light irradiation

Tiangui Jianga, Kai Wanga, Ting Guoa, Xiaoyong Wua, Gaoke Zhanga,b   

  1. a Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China;
    b State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, Hubei, China
  • Received:2019-04-09 Revised:2019-05-01 Online:2020-01-18 Published:2019-10-22
  • Supported by:
    This work was supported by the Natural Science Foundation of Hubei Province (2016CFA078), and the National Natural Science Foundation of China (51472194).

Abstract: Constructing Z-scheme heterojunction to improve the separation efficiency of photogenerated carriers of photocatalysts has gained extensive attention. In this work, we fabricated a novel Z-scheme MoO3/Bi2O4 heterojunction photocatalyst by a hydrothermal method. XPS analysis results indicated that strong interaction between MoO3 and Bi2O4 is generated, which contributes to charge transfer and separation of the photogenerated carriers. This was confirmed by photoluminescence (PL) and electrochemical impedance spectroscopy (EIS) tests. The photocatalytic performance of the as-synthesized photocatalysts was evaluated by degrading rhodamine B (RhB) in aqueous solution under visible light irradiation, showing that 15% MoO3/Bi2O4 (15-MB) composite exhibited the highest photocatalytic activity, which is 2 times higher than that of Bi2O4. Besides, the heterojunction photocatalyst can keep good photocatalytic activity and stability after five recycles. Trapping experiments demonstrated that the dominant active radicals in photocatalytic reactions are superoxide radical (·O2-) and holes (h+), indicating that the 15-MB composite is a Z-scheme photocatalyst. Finally, the mechanism of the Z-scheme MoO3/Bi2O4 composite for photo-degrading RhB in aqueous solution is proposed. This work provides a promising strategy for designing Bi-based Z-scheme heterojunction photocatalysts for highly efficient removal of environmental pollutants.

Key words: MoO3, Bi2O4, Z-scheme, Heterojunction, Visible-light, Degradation