Introduction –
Cobalt hydroxide is an inorganic compound represented by CO(OH)2. It is insoluble in water, and when tried to dissolve in water, it turns pink. It is available in alpha, beta forms and as nanotubes. The beta form is packed as brucite crystal, octahedral molecular geometry. The beta form is the pure form of cobalt hydroxide. The alpha form is a complex compound, with alternating positive and negative charges. The nanotube forms of cobalt hydroxide is used in research purposes in the field of nanotechnology.
Manufacturing process-
Cobalt salt reacts with an alkali metal hydroxide, to form cobalt hydroxide, like the following reaction-
Co2+ + 2 NaOH → Co(OH)2 + 2 Na+
Another way of preparing cobalt hydroxide is by using cobalt nitrate and trimethylamine.
Applications-
Cobalt hydroxide is used in paints, varnishes, inks etc as drying agents. It is also used in the preparation of catalysts and in manufacturing of battery electrodes. In particular, the development of inexpensive Co(OH)2 catalysts to replace Pt in fuel cell electrodes for the oxygen reduction reaction (ORR) has been an area of increasing interest.