Water Oxidation Reaction Catalyzed by Co3O4 Treated with Organic Compounds

This work describes the water oxidation reaction by the spinel Co3O4 nanopowder treated with coordinating organic compounds. Treatment of Co3O4 led to an increase in the Co3+ species at the oxide surface, probably due to stabilization by the adsorbed organic compounds, as well as partial oxidation of Co2+ to Co3+ ions by oxygen from air. Oxygen evolution reaction (OER) tests were carried out against the sacrificial oxidant cerium­(IV) ammonium nitrate (CAN), and higher TOF values were obtained for the treated samples in relation to the pure oxide, showing an influence of the Co3+/Co2+ ratio in the catalytic activity. The catalysts could be recycled up to five times without considerable loss of activity.