These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Electrochemical oxidation characteristics of p-substituted phenols using a boron-doped diamond electrode.
    Author: Zhu X, Shi S, Wei J, Lv F, Zhao H, Kong J, He Q, Ni J.
    Journal: Environ Sci Technol; 2007 Sep 15; 41(18):6541-6. PubMed ID: 17948806.
    Abstract:
    Electrochemical oxidation of some p-substituted phenols (p-nitrophenol, p-hydroxybenzaldehyde, phenol, p-cresol, and p-methoxyphenol) with electron-donating and -withdrawing substituents was studied to reveal the relationship between the structure and the electrochemical reactivity of p-substituted phenols using a boron-doped diamond electrode by voltammetry and bulk electrolysis. Voltammetric study shows that the oxidation peak potentials of p-substituted phenols become more positive with an increase of Hammett's constants, that is, the direct electrochemical oxidation of p-substituted phenol with an electron-withdrawing group is more difficult than that of p-substituted phenol with an electron-donating group. However,the p-substituted phenols with electron-withdrawing groups are degraded faster than those with electron-donating groups in bulk electrolysis, which is opposite to the result obtained on the Pt electrode. These results indicate that the p-substituted phenols are mainly degraded by indirect electrochemical oxidation with hydroxyl radicals on a boron-doped diamond electrode. Under the attack of hydroxyl radicals, the release of p-substituted groups from the aromatic ring is the rate-limiting step. Since electron-withdrawing groups are easy to be released, the p-substituted phenols with these groups are degraded faster than those with electron-donating groups. Therefore, the degradation rates of the p-substituted phenols rise with an increase of Hammett's constants.
    [Abstract] [Full Text] [Related] [New Search]