Cyclic voltammogram and current-voltage curve of potassium iodide were measured on Ti/RuO₂ electrode, prepared by thermal decomposition method, to study the reaction for iodate formation by oxidation of iodide and macro-electrolysis was carried out to investigate the optimum conditions for electrolytic preparation of iodate from potassium iodide solution.
At first, iodide is oxidized to iodine by reversible electrode reaction and then iodine is oxidized to iodate, depends on the pH of electrolyte, by irreversible electrode reaction or chemical reaction.
The electrolytic preparation of iodate is effective in weak alkaline solution （pH 10）. As a result of electrolysis at constant voltage and constant current, maximum current efficiency was obtained at 1.05 V and 30 A/dm².