Synthese des hydroxydes de cobalt, nickel et cadmium par oxydation des metaux par l'oxygene en presence d'ammoniaque

Pure hydroxides of cobalt, nickel and cadmium have been synthesized by a new route. The powdered metals have been oxidized by dioxygen in aqueous ammonia. The reactions have been carried out at ambiant temperature and pressure. Cobalt hydroxyde Co(OH) 2 is slowly oxidized to CoOOH by subsequent exposure to dioxygen. the Ni(OH) 2 synthesis is easier if nickel metal is activated by exposure to dihydrogen at about 300°C.