ELECTROCRYSTALLIZATION OF THALLIUM OXIDES IN AN ALKALINE-MEDIUM - MECHANISM OF THE PROCESSES IN THE REGION OF LOW AND HIGH OVERPOTENTIALS

The kinetics of the potentiostatic deposition of thallium-oxide films from alkaline Tl2SO4 solutions on a polycrystalline platinum substrate and also the mechanism of the reaction-product cathodic reduction were studied by chronoamperometric and coulometric methods. It was shown that the deposition mechanisms and the properties of the resulting products are substantially different at low and high overpotentials. On the basis of the obtained data, the mechanism of the processes was suggested for the system studied, which includes the stages of formation of a mixed-valent oxide, a hydrated Tl(III) oxide, and a slow chemical stage of dehydration.