玻碳电极上碘仿电解合成的机理

Mechanism of Iodoform Electrosynthesis on Glassy Carbon Electrode

本文采用循环伏安法研究了在Na2CO3溶液介质中KI在金电极和玻碳电极上的电化学行为。在0.2V^1.2V电位范围内玻碳电极上仅发生I-被氧化为I2的反应,而在金电极上除了I-被氧化为I2外,还发生生成IO3-的氧化反应。同时通过不同电位扫描速度下的循环伏安行为分析发现电极过程为传质控制步骤。

The mechanism of iodoform electrosynthesis was investigated for the electrochemical reaction system of Na2C03 and KI by cyclic vohammetry on gold electrode and glassy carbon electrode, respectively. The difference of the cyclic voltammograms ob- tained on the two electrodes was obvious. In the range of 0.2 to 1.2V, the anodic oxidation reaction was more complex on gold electrode than on glassy carbon electrode. On the gold electrode, except for the process that iodide ion was oxidized to form io- dine, the new - formed iodine was electro - oxidized further with the formation of iodate, which was not obtained on glassy carbon electrode. The cyclic voltammograms with different rates of potential scan identified that the electrochemical reactions taking place on glassy carbon electrode in the range of 0.2 to 0.8V were mass transportation controlled process.