Photocatalytic formation of hydrogen peroxide over highly porous illuminated ZnO and TiO2thin film

Abstract The photocatalytic formation of hydrogen peroxide over ZnO and TiO2thin films has been investigated in aqueous phase in the presence of molecular oxygen as an electron acceptor. These films are highly porous and showed enhanced catalytic activity in the photochemical formation of hydrogen peroxide. The amount of H2O2formed during 2 hour light illumination is 4–6 μM and the rates of formation of hydrogen peroxide of both the films are almost comparable. The yield of hydrogen peroxide increases with the increase in irradiation time and a trend of steady state concentration of H2O2is observed in the case of TiO2thin film. Photodissolution of ZnO particles is observed in some extent during the process of prolonged UV light illumination.