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

Abstract

Pure and copper-substituted cobaltites have been prepared by the hydroxide-carbonate-co-precipitation method and investigated in the form of films on nickel for their electrocatalytic properties towards oxygen evolution in alkaline solution. Results showed the marked improvement in the roughness as well as in the apparent electrocatalytic activity of the oxide. However, the substitution of Co by Cu in the spinel lattice did not indicate any significant electrocatalytic influence on the rate of oxygen evolution. Values of the Tafel slope and the reaction order with respect to OH- concentration have been observed to be ≅ 2.3 RT/F and one at low overpotential and 2 × 2.3 RT/F and one at high overpotential with each catalyst regardless of its nature.