Prompting direct single electron transfer to produce non-radical 1O2/H* by electro-activating peroxydisulfate process with core-shell cathode

Huajing Zhou; Dongxiu Lu; Shangquan Fang; Chang Liu; Yuancai Chen; Yongyou Hu; Qijin Luo

doi:10.1016/j.jenvman.2021.112294

Prompting direct single electron transfer to produce non-radical ¹O₂/H* by electro-activating peroxydisulfate process with core-shell cathode

J Environ Manage. 2021 Jun 1:287:112294. doi: 10.1016/j.jenvman.2021.112294. Epub 2021 Mar 10.

Authors

Huajing Zhou¹, Dongxiu Lu¹, Shangquan Fang¹, Chang Liu², Yuancai Chen³, Yongyou Hu¹, Qijin Luo⁴

Affiliations

¹ Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
² South China Institute of Environmental Sciences, MEE, Guangzhou, 510006, China.
³ Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China. Electronic address: chenyc@scut.edu.cn.
⁴ Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; South China Institute of Environmental Sciences, MEE, Guangzhou, 510006, China. Electronic address: luoqijin@scies.org.

PMID: 33714046
DOI: 10.1016/j.jenvman.2021.112294

Abstract

A novel heteroatomic N, P and S co-doped core-shell material (MnFe₃O₄@PZS) was synthesized by a simple polycondensation hydro-thermal method, and used as the cathode to cooperate with electron-catalysis to activate persulfate (S₂O₈^2-) (E-MnFe₃O₄@PZS-PDS) for tetracycline (TTC) degradation. Radical scavenger studies demonstrated that non-radicals including atomic H* and singlet oxygen (¹O₂) rather than sulfate and hydroxyl radicals were the crucial reactive oxygen species (ROS). Electrochemical analysis indicated that Mn doping could promote electro-catalytic process via diverting pathway from four/two-electron to one-electron to generate non-radical H*/¹O₂ at the cathode, including one-electron oxygen reduction reaction (1e-ORR) (O₂→¹O₂), and one-electron hydrogen reduction reaction (1e-HRR) (H₂O+e^-→H^∗), as evidenced by the lowest onset potential (0.072 V) together with electron transfer number (n = 1.65). Besides, the regeneration/reduction of Fe^Ⅱ/Ⅲ/Mn^Ⅱ/Ⅲ/Ⅳ and persulfate will not cause excessive consumption of electron and chemicals due to that could directly get the electron individually from the cathode and anode, and finally TTC could be completely degraded with low energy consumption (0.655 kWh m^-3). This study provides new insights into the direct single electron activating PDS to produce non-radical H*/¹O₂ via core-shell catalytic MnFe₃O₄@PZS, and displays a promising application in wastewater treatment.

Keywords: (1)O(2)/H*; Core-shell microspheres; Direct one-electron transfer; Electro-activation; Non-free radical reactions.

MeSH terms

Catalysis
Electrodes
Electrons*
Oxidation-Reduction
Tetracycline
Water Purification*

Substances

Tetracycline