Enhanced organics degradation by three-dimensional (3D) electrochemical activation of persulfate using sulfur-doped carbon particle electrode: The role of thiophene sulfur functional group and specific capacitance

Fei Qi; Zequan Zeng; Qin Wen; Zhanggen Huang

doi:10.1016/j.jhazmat.2021.125810

Enhanced organics degradation by three-dimensional (3D) electrochemical activation of persulfate using sulfur-doped carbon particle electrode: The role of thiophene sulfur functional group and specific capacitance

J Hazard Mater. 2021 Aug 15:416:125810. doi: 10.1016/j.jhazmat.2021.125810. Epub 2021 Apr 6.

Authors

Fei Qi¹, Zequan Zeng², Qin Wen¹, Zhanggen Huang³

Affiliations

¹ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
² State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China. Electronic address: zengzequan@sxicc.ac.cn.
³ State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China. Electronic address: zghuang@sxicc.ac.cn.

PMID: 33882388
DOI: 10.1016/j.jhazmat.2021.125810

Abstract

For further enhancing the electrochemical oxidation performance, sulfur-doped carbon particle electrode was employed in the three-dimensional (3D) electro-assisted activation of persulfate process (ACS/PS/EC). Herein, an in situ S-doped activated carbon (ACS) was prepared and applied as the particle electrode as well as catalyst in ACS/PS/EC system. Several carbon particle electrodes with different annealing temperature were prepared and characterized via EA, BET, XPS and Raman spectra. Cyclic voltammetry (CV) was perform to obtain the specific capacitance and investigate the interfacial electron transfer of ACS particle. The results of comparative experiments showed significant synergy between electric and catalytic activations of PS. Especially, the as-prepared sample treated at 850 °C (ACS-850) exhibited an outstanding catalytic performance, and the phenol degradation rate was greatly improved by nearly 100% with the application of electric field. By comparing of several carbon particle electrodes with different functional groups and specific capacitances, it is revealed that thiophene sulfur functional group is the mainly active site for both electric and catalytic activation of PS, and the specific capacitance acts as assistant factor. Quenching experiments proved that the 3D electro-assisted activation of PS proceeded through both radical and non-radical pathway. Possible mechanism for ACS/PS/EC electrochemical process was proposed.

Keywords: 3D electrode; Activated carbon; Persulfate oxidation; Phenol degradation; Sulfur doping.