Photoelectrochemical and photocatalytic systems based on titanates for hydrogen peroxide formation

The development of efficient, sustainable, cheap and safe methods for the synthesis of hydrogen peroxide is a very important challenge from the environmental viewpoint, since H2O2 can be used as a solar fuel or for degradation of organic, inorganic and biologic pollutants from wastewater. Efficient photocatalytic or photo electrochemical formation of hydrogen peroxide from water and/or oxygen in an acidic medium has been obtained using nickel or cobalt titanates under visible light illumination. The concentration of H2O2 achieved in the photoreaction reached 2.5 mM when nickel titanate was irradiated for 1 h in oxygen saturated suspension. In such conditions, NiTiO3 provide active sides for both, oxygen reduction and water oxidation leading to H2O2 formation.