Electrocatalytic properties of CuxCo3-xO4 (0 <= x <= 1) obtained by a new precipitation method for oxygen evolution

Pure and copper-substituted cobaltites have been prepared by the hydroxide- carbonate-co-precipitation method and investigated in the form of films on nickle for their electrocatalytic properties towards oxygen evolution in al kaline solution. Results showed the marked improvement in the roughness as well as in the apparent electrocatalytic activity of the oxide. However, th e substitution of Co by Cu in the spinel lattice did not indicate any signi ficant electrocatalytic influence on the rate of oxygen evolution. Values o f the Tafel slope and the reaction order with respect to OH- concentration have been observed to be similar or equal to 2.3 RT/F and one at low overpo tential and 2 X 2.3 RT/F and one at high overpotential with each catalyst r egardless of its nature.