Sustained production of H2O2 on irradiated TiO2- fluoride systems.

UV irradiation of fluorinated TiO(2) suspensions in water, in the presence of oxygen and a hole scavenger, leads to the production of H(2)O(2) with steady state concentration levels up to 1.3 millimolar; the H(2)O(2) formation rate follows the TiO(2) surface speciation, being maximum when the surface is completely covered by [triple bond]Ti-F groups; these results outline the importance of surface speciation on the photocatalytic process.