ELECTROCHEMICAL OXIDATION OF IODIDE AT A GLASSY CARBON ELECTRODE IN METHYLENE CHLORIDE AT VARIOUS TEMPERATURES

Anodic electrooxidation of iodide in 0.1 mol L-1 TBAP/ CH2C1(2) was studied electrochemically via cyclic voltammetry, convolution transforms voltammetry, chronoamperometry and chronopotentiometry techniques at a glassy carbon electrode (GCE) at various temperatures ranging from -20 °C to 21 °C. It was found that at less positive potential triiodide (I-3) is formed followed by a moderate fast chemical process, while at more positive potential, the triiodide is oxidized to iodine (I2) followed by another chemical process, i.e EC1EC2 scheme. The effect of lowering the temperature on the heterogeneous electron transfer rate constant and the diffusion coefficient was discussed. The relevant chemical and electrochemical parameters of the electrode reaction were determined. The accurate test of the parameters evaluated experimentally was verified by comparing the experimental voltammograms with the simulated one.