SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2023, Vol. 57 ›› Issue (5): 162-172.DOI: 10.1016/j.cjche.2022.08.021

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Investigation of photoelectrocatalytic degradation mechanism of methylene blue by α-Fe2O3 nanorods array

Yaqiao Liu1, Shuozhen Hu1, Xinsheng Zhang1, Shigang Sun2   

  1. 1. State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
    2. State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
  • Received:2022-04-26 Revised:2022-07-31 Online:2023-07-08 Published:2023-05-28
  • Contact: Shuozhen Hu,E-mail:shuozhen.hu@ecust.edu.cn;Shigang Sun,E-mail:sgsun@xmu.edu.cn
  • Supported by:
    This work is financially supported by the National Natural Science Foundation of China (22005097) and the State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, P.R. China (201815). Reference 3000 potentiostat is donated by GAMRY Instruments.

Investigation of photoelectrocatalytic degradation mechanism of methylene blue by α-Fe2O3 nanorods array

Yaqiao Liu1, Shuozhen Hu1, Xinsheng Zhang1, Shigang Sun2   

  1. 1. State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
    2. State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
  • 通讯作者: Shuozhen Hu,E-mail:shuozhen.hu@ecust.edu.cn;Shigang Sun,E-mail:sgsun@xmu.edu.cn
  • 基金资助:
    This work is financially supported by the National Natural Science Foundation of China (22005097) and the State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, P.R. China (201815). Reference 3000 potentiostat is donated by GAMRY Instruments.

Abstract: Efficiently and thoroughly degrading organic dyes in wastewater is of great importance and challenge. Herein, vertically oriented mesoporous α-Fe2O3 nanorods array (α-Fe2O3-NA) is directly grown on fluorine-doped tin oxide (FTO) glass and employed as the photoanode for photoelectrocatalytic degradation of methylene blue simulated dye wastewater. The Ov sites on the α-Fe2O3-NA surface are the active sites for methylene blue (MB) adsorption. Electrons transfer from the adsorbed MB to Fe-O is detected. Compared with electrocatalytic and photocatalytic degradation processes, the photoelectrocatalytic (PEC) process exhibited the best degrading performance and the largest kinetic constant. Hydroxyl, superoxide free radicals, and photo-generated holes play a jointly leading role in the PEC degradation. A possible degrading pathway is suggested by liquid chromatography-mass spectroscopy analysis. This work demonstrates that photoelectrocatalysis by α-Fe2O3-NA has a remarkable superiority over photocatalysis and electrocatalysis in MB degradation. The in-depth investigation of photoelectrocatalytic degradation mechanism in this study is meaningful for organic wastewater treatment.

Key words: α-Fe2O3 nanorods array, Methylene blue, Photoelectrocatalytic degradation mechanism, Free radicals, Photo-generated holes

摘要: Efficiently and thoroughly degrading organic dyes in wastewater is of great importance and challenge. Herein, vertically oriented mesoporous α-Fe2O3 nanorods array (α-Fe2O3-NA) is directly grown on fluorine-doped tin oxide (FTO) glass and employed as the photoanode for photoelectrocatalytic degradation of methylene blue simulated dye wastewater. The Ov sites on the α-Fe2O3-NA surface are the active sites for methylene blue (MB) adsorption. Electrons transfer from the adsorbed MB to Fe-O is detected. Compared with electrocatalytic and photocatalytic degradation processes, the photoelectrocatalytic (PEC) process exhibited the best degrading performance and the largest kinetic constant. Hydroxyl, superoxide free radicals, and photo-generated holes play a jointly leading role in the PEC degradation. A possible degrading pathway is suggested by liquid chromatography-mass spectroscopy analysis. This work demonstrates that photoelectrocatalysis by α-Fe2O3-NA has a remarkable superiority over photocatalysis and electrocatalysis in MB degradation. The in-depth investigation of photoelectrocatalytic degradation mechanism in this study is meaningful for organic wastewater treatment.

关键词: α-Fe2O3 nanorods array, Methylene blue, Photoelectrocatalytic degradation mechanism, Free radicals, Photo-generated holes