Effect of nitro substituent on electrochemical oxidation of phenols at boron-doped diamond anodes

Yi Jiang, Xiuping Zhu, Hongna Li, Jinren Ni

Research output: Journal article publicationJournal articleAcademic researchpeer-review

29 Citations (Scopus)

Abstract

In order to investigate nitro-substitutent's effect on degradation of phenols at boron-doped diamond (BDD) anodes, cyclic voltammetries of three nitrophenol isomers: 2-nitrophenol (2NP), 3-nitrophenol (3NP) and 4-nitrophenol (4NP) were studied, and their bulk electrolysis results were compared with phenol's (Ph) under alkaline condition. The voltammetric study showed nitrophenols could be attacked by hydroxyl radicals and nitro-group was released from the aromatic ring. Results of bulk electrolysis showed degradation of all phenols were fit to a pseudo first-order equation and followed in this order: 2NP > 4NP > 3NP > Ph. Molecular structures, especially carbon atom charge, significantly influenced the electrochemical oxidation of these isomers. Intermediates were analyzed during the electrolysis process, and were mainly catechol, resorcinol, hydroquinone, and carboxylic acids, such as acetic acid and oxalic acid. A simple degradation pathway was proposed. Moreover, a linear increasing relationship between degradation rates and Hammett constants of the studied phenols was observed, which demonstrated that electrochemical oxidation of these phenols was mainly initiated by electrophilic attack of hydroxyl radicals at BDD anodes.

Original languageEnglish
Pages (from-to)1093-1099
Number of pages7
JournalChemosphere
Volume78
Issue number9
DOIs
Publication statusPublished - 1 Feb 2010
Externally publishedYes

Keywords

  • Boron-doped diamond electrodes
  • Electrochemical oxidation
  • Nitrophenol
  • Wastewater treatment

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Chemistry(all)
  • Pollution
  • Health, Toxicology and Mutagenesis

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