硫代水杨酸在活化玻碳电极上的电氧化反应机理

doi:10.3724/SP.J.1095.2014.30210

摘要/Abstract

摘要： 探讨了硫代水杨酸(TSA)在电化学活化后的玻碳电极(GCE)上的电化学行为，经循环伏安法研究表明，在氯化钾底液中，TSA为不可逆电氧化过程。考察了不同pH值时TSA的形态分布和氧化峰电位的变化，随着pH值的增加，中性分子C6H4(COOH)SH含量下降，而C6H4(COO-)SH随之增加，同时氧化峰电位逐渐降低，表明C6H4(COO-)SH比C6H4(COOH)SH更易被电极氧化。峰电位在pH=6后下降的趋势变缓；当pH值升至11碱性较强时，阳极氧化峰消失，推测此时由于参与电极反应的H+缺乏，抑制了电极反应的进行。其电氧化过程为平均每转移3个电子，同时有1个氢离子参与反应，推断其最终产物为2-磺基苯甲酸。

关键词: 硫代水杨酸, 循环伏安法, 活化玻碳电极, 电氧化机理

Abstract: Electrochemical behavior of thiosalicylic acid(TSA) on activated glassy carbon electrode(GCE) was studied. TSA exhibited irreversible electrochemical oxidation process in KCl solution by cyclic voltammetry(CV). Neutral/anionic TSA distribution and anodic potential shifts at different pH were also discussed. With increase of pH, the anodic potential gradually decreases while the concentration of C6H4(COO-)SH increases. This indicates that C6H4(COO-)SH is more readily to be oxidized than C6H4(COOH)SH. The decreasing tendency of potential slows down when the pH is above 6. When the pH is elevated to 11, the disappearance of anodic peak indicates that the electrode reaction is prohibited in the absences of H+. During the electrochemical oxidation of TSA, one H+ participates in the reaction with average every three electrons transferring. Therefore, the final product is inferred as 2-sulfobenzoic acid.

Key words: thiosalicylic acid, cyclic voltammetry, activated glassy carbon electrode, electrochemical oxidation mechanism

中图分类号:

O646

刘文涵, 袁荣辉, 滕渊洁, 马淳安. 硫代水杨酸在活化玻碳电极上的电氧化反应机理[J]. 应用化学, DOI: 10.3724/SP.J.1095.2014.30210.

LIU Wenhan*, YUAN Ronghui, TENG Yuanjie, MA Chunan. Electrochemical Oxidation Mechanism of Thiosalicylic Acid on Activated Glassy Carbon Electrode[J]. Chinese Journal of Applied Chemistry, DOI: 10.3724/SP.J.1095.2014.30210.

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