Schroeder Chelsea M, Koehler Taylor M, Ohlhorst Kristiane K, Leadbeater Nicholas E
Department of Chemistry, University of Connecticut 55 North Eagleville Road Storrs Connecticut 06269 USA
RSC Adv. 2023 Nov 16;13(48):33559-33565. doi: 10.1039/d3ra06634g.
An apparatus for real-time monitoring of electrochemical processes using UV-visible spectrophotometry has been used to optimise the electrochemically-activated persulfate decolorisation of Acid Orange 7. The impacts of varying electrode composition, current density, persulfate loading, and stirring speed on the rate of decolorisation have been probed. Decolorisation through this activated persulfate approach was compared to that using anodic oxidation for nine dyes; three from each of the azo, triarylmethane, and xanthene families. The core structure and presence of functional groups have a significant impact on the rate of decolorisation. Azo and xanthene dyes decolorise faster than triarylmethane dyes, while electron-withdrawing groups and halogens are especially detrimental to the rate of decolorisation. Electrochemically-activated persulfate resulted in faster decolorization than anodic oxidation for almost every dye, an effect that was enhanced with the electron-deficient substrates. This type of systematic structural comparison study is essential for designing electrochemical degradation procedures for the remediation of real wastewater.
一种利用紫外可见分光光度法实时监测电化学过程的装置已被用于优化酸性橙7的电化学活化过硫酸盐脱色过程。研究了不同电极组成、电流密度、过硫酸盐负载量和搅拌速度对脱色速率的影响。将这种活化过硫酸盐方法的脱色效果与阳极氧化法对九种染料的脱色效果进行了比较；这九种染料分别来自偶氮、三芳基甲烷和呫吨三个家族，各三种。核心结构和官能团的存在对脱色速率有显著影响。偶氮染料和呫吨染料的脱色速度比三芳基甲烷染料快，而吸电子基团和卤素对脱色速率尤其不利。对于几乎每种染料，电化学活化过硫酸盐比阳极氧化导致更快的脱色，对于缺电子底物，这种效果会增强。这种系统的结构比较研究对于设计用于实际废水修复的电化学降解程序至关重要。
