Magnetic field assisted α-Fe2O3/Zn1-xFexO heterojunctions for accelerating antiviral agents degradation under visible-light

Yadong Wu; Tao Li; Xulin Ren; Yuanxiang Fu; Hongyan Zhang; Xiaoqing Feng; Hongsheng Huang; Ruishi Xie

doi:10.1016/j.jece.2021.106990

Magnetic field assisted α-Fe₂O₃/Zn_1-xFe_xO heterojunctions for accelerating antiviral agents degradation under visible-light

J Environ Chem Eng. 2022 Feb;10(1):106990. doi: 10.1016/j.jece.2021.106990. Epub 2021 Dec 11.

Authors

Yadong Wu¹, Tao Li¹, Xulin Ren¹, Yuanxiang Fu¹, Hongyan Zhang¹, Xiaoqing Feng¹, Hongsheng Huang¹, Ruishi Xie²

Affiliations

¹ School of International Education, School of Chemical Engineering, Guizhou Institute of Technology, Guiyang 550003, PR China.
² School of Materials Science and Engineering, Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010, PR China.

Abstract

Reducing the recombination efficiency of photo-induced carriers has been found as an effective means to improve the degradation of antiviral agents. Given that the Lorentz forces can cause the abnormal charge to move in the opposite direction, external magnetic field improved α-Fe₂O₃/Zn_1-xFe_xO heterojunctions (FZHx) were developed to remove increasing antiviral agents that were attributed to the COVID-19 pandemic under visible light. The characterization of the mentioned FZHx in the external magnetic field indicated that FZHx had perfect photocatalytic activity for degrading antiviral agents. In the external magnetic field, the quantities of photo-generated carriers and free radicals (•OH and •O₂ ^-) derived from FZHx increased significantly, which improved antiviral agent removal by 30.0%. Though the band structure (α-Fe₂O₃) is unlikely to change due to some orders of magnitude weaker of Zeeman energy in magnetic fields, which insignificantly impacts photocatalytic performance. However, this study proposed a strategy of negative magnetoresistance effects and heterojunctions to facilitate the separation and transfer of photo-induced carriers in magnetic fields. Based on the proposed strategy, spin oriented electrons were selected and accumulated on the conduction band, which contributed to the degradation of antiviral agents. Overall, this study presented novel insights into the improved degradation performance of antiviral agents by applying Fe-based heterojunctions in an external magnetic field.

Keywords: Free radical; Heterojunctions; Magnetic-field; Magnetoresistance effect; Photocatalytic activity.