Mesoporous Co₃O₄ as an electrocatalyst for water oxidation

Mesoporous Co₃O₄ has been prepared using porous silica as a hard template via a nanocasting route and its electrocatalytic properties were investigated as an oxygen evolution catalyst for the electrolysis of water. The ordered mesostructured Co₃O₄ shows dramatically increased catalytic activity compared to that of bulk Co₃O₄. Enhanced catalytic activity was achieved with high porosity and surface area, and the water oxidation overpotential (η) of the ordered mesoporous Co₃O₄ decreases significantly as the surface area increases. The mesoporous Co₃O₄ also shows excellent structural stability in alkaline media. After 100 min under 0.8 V (versus Ag/AgCl) applied bias, the sample maintains the ordered mesoporous structure with little deactivation of the catalytic properties.