Ring-disk electrode studies of the open-circuit dissolution of iodine films formed during the anodic oxidation of iodide on platinum

Abstract The open-circuit behavior of iodine films formed on platinum by electrooxidation of iodide was studied at rotating disk and rotating ring-disk electrodes. The potential transient and ring current transient at open circuit for c I − >0.012 M can be explained by assuming: (1) convective-diffusion controlled dissolution of the film; (2) establishment of the I 2 +I − → I 3 − equilibrium; (3) establishment of the I 2 (solid) →I 2 (solution) equilibrium. The behavior at lower concentrations of c I − suggests that convective-diffusion control is absent.