Photo-degradation activity of sputter-deposited nitrogen-doped titania thin films

Various approaches have been reported during the last decade to enhance the photo-catalytic and super-hydrophilic characteristics of the intrinsic TiO2 materials. Results on the photo-degradation activity of RF-sputtered nitrogen-doped titania thin films are presented here with respect to two environmental pollutants in gas- and liquid phases, as a function of dopant concentration. This study was accomplished by monitoring the time dependence of pollutant concentration in contact with the films, both under UV and solar light illumination. The synergic effects of surface morphology, crystalline and electronic structure of the materials are discussed in relation with the observed experimental facts. The results presented here show a close correlation between the oxidative power of the films and their previously reported wettability features.