Preparation and characterization of cobalt oxide by electrochemical technique

Cobalt oxide was prepared from synthetic cobalt nitrate solutions through two step process; electrolysis of cobalt nitrate solution to produce cobalt hydroxide and then preparation of cobalt oxide by calcination of cobalt hydroxide. Cathodic reduction of cobalt nitrate solution at pH ~4 with a cobalt concentration of 28g/L at a current density of 200A/m 2 lead to formation of β -Co(OH) 2 with a current efficiency of 41%. On increasing current density, the current efficiency has increased and reached a maxima of 59% at an applied current density of 500 A/m 2 . The effect of Co(II) concentration was studied and found that with increase in Co(II) concentration from 28g/ L to 42 g/L the current efficiency increased to 59% at an applied current density of 200 A/m 2 . The β -cobalt hydroxide when calcined at 300°C the corresponding β -Co 3 O 4 was obtained. The morphology and structure of both the cobalt hydroxide and oxide were characterized by scanning electron microscope (SEM) and X-ray diffractometer (XRD) and the discharge capacity of cobalt oxide was measured.