Electrochemical study of a novel high-efficiency PbO2 anode based on a cerium-graphene oxide co-doping strategy: Electrodeposition mechanism, parameter optimization, and degradation pathways

Xiaolu Fu; Yanhe Han; Han Xu; Zhimin Su; Lina Liu

doi:10.1016/j.jhazmat.2021.126890

Electrochemical study of a novel high-efficiency PbO₂ anode based on a cerium-graphene oxide co-doping strategy: Electrodeposition mechanism, parameter optimization, and degradation pathways

J Hazard Mater. 2022 Jan 15:422:126890. doi: 10.1016/j.jhazmat.2021.126890. Epub 2021 Aug 12.

Authors

Xiaolu Fu¹, Yanhe Han², Han Xu¹, Zhimin Su¹, Lina Liu¹

Affiliations

¹ Department of Environmental Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China.
² Department of Environmental Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China. Electronic address: hanyanhe@bipt.edu.cn.

PMID: 34418839
DOI: 10.1016/j.jhazmat.2021.126890

Abstract

A novel and efficient Ti/SnO₂-Sb/PbO₂-GO-Ce electrode was successfully fabricated based on the co-deposition of Ce ions and graphene oxide (GO) into β-PbO₂ crystals and used as an anode for electrocatalytic oxidation of phenol. The electrodeposition mechanism, parameter optimization, mechanism analysis, and potential degradation pathways were discussed in depth. The co-doping of GO and Ce resulted in the high directional specificity of β(301), orderly and dense grain arrangement of PbO₂ crystals. At the same time, the oxygen evolution potential, •OH generation capacity and lifetime were also improved. The effects of experimental parameters on phenol removal efficiency were evaluated, including the applied current density, electrode gap, supporting electrolyte, initial NaCl concentration, initial pH, and initial phenol concentration. Under the optimal conditions, the removal efficiency of phenol can reach 375.6 g m^-2 h^-1 for 20 min electrolysis, which is about 1.2 times that of the pure PbO₂ electrode. The active oxygen species (•OH, ClO^- and HClO) were important attributes to the degradation of phenol. Additionally, a potential degradation pathway for phenol was proposed. After 10 successive recycles, there was no significant difference of the electro-generated •OH, cell voltage and phenol removal rate, which confirms the stability and admirable reusability of Ti/SnO₂-Sb/PbO₂-GO-Ce electrode.

Keywords: Degradation mechanism; Electrochemical oxidation; GO; PbO(2) composite electrode; Phenol.