@article {JIANG2020126033,
	title = {Radical attack and mineralization mechanisms on electrochemical oxidation of p-substituted phenols at boron-doped diamond anodes},
	journal = {Chemosphere},
	volume = {248},
	year = {2020},
	pages = {126033},
	abstract = {Degradation of phenols with different substituent groups (including {\textendash}OCH3, {\textendash}CHO, {\textendash}NHCOCH3, {\textendash}NO2, and~-Cl) at boron-doped diamond (BDD) anodes has been studied previously based on the removal efficiency and {\textbullet}OH detection. Innovatively, formations of CO2 gas and various inorganic ions were examined to probe the mineralization process combined with quantitative structure-activity relationship (QSAR) analysis. As results, all phenols were efficiently degraded within 8~h with high COD removal efficiency. Three primary intermediates (hydroquinone, 1,4-benzoquinone and catechol) were identified during electrochemical oxidation and degradation pathway was proposed. More importantly, CO2 transformation efficiency ranked as: no N or Cl contained phenols (p-CHO, p-OCH3 and Ph)~\&gt;~N-contained phenols (p-NHCOCH3 and p-NO2)~\&gt;~Cl-contained phenols (p-Cl and o,p-Cl). Carbon mass balance study suggested formation of inorganic carbon (H2CO3, CO32- and HCO3-) and CO2 after organic carbon elimination. Inorganic nitrogen species (NH4+, NO3- and NO2-) and chlorine species (Cl-, ClO3- and ClO4-) were also formed after N- and Cl-contained phenols mineralization, while no volatile nitrogen species were detected. The phenols with electron-withdrawing substituents were easier to be oxidized than those with electron-donating substituents. QSAR analysis indicated that the reaction rate constant (k1) for phenols degradation was highly related to Hammett constant (∑σo,m,p) and energy gap (ELUMO - EHOMO) of the compound (R2~=~0.908), which were key parameters on evaluating the effect of structural moieties on electronic character and the chemical stability upon radical attack for a specific compound. This study presents clear evidence on mineralization mechanisms of phenols degradation at BDD anodes.},
	keywords = {Boron-doped diamond, Electrochemical oxidation, Mineralization, Phenolic compounds, QSAR analysis},
	issn = {0045-6535},
	doi = {https://doi.org/10.1016/j.chemosphere.2020.126033},
	url = {http://www.sciencedirect.com/science/article/pii/S0045653520302265},
	author = {Jiang, Huan and Dang, Chenyuan and Liu, Wen and Ting Wang}
}
