STUDIES OF THE INITIAL OXIDATION OF COBALT IN ALKALINE-SOLUTIONS USING SCANNING ELECTROCHEMICAL MICROSCOPE

Scanning electrochemical microscopy and atomic force microscopy were u sed together with cyclic voltammetry and rotating ring disc experiment s to study the initial oxidation of cobalt in alkaline solution. The r esults show that the mechanism of cobalt oxidation involves a solid st ate path as well as dissolution combined with precipitation. In the co ncentration region studied, 0.1-1 M NaOH, the solid state path seems t o predominate. The AFM images clearly show a three-dimensional growth mechanism and that the initial oxidation starts at active sites at the surface.