Influence of carbon-ion irradiation and hydrogen-plasma treatment on photocatalytic properties of titanium dioxide films

Abstract Effects of carbon-ion irradiation and hydrogen-plasma treatment for anatase TiO 2 films were examined by decomposition of a dye, and the photoinduced transient charge separation (PITCS) method. For the TiO 2 films prepared by anodic oxidation, the photocatalytic activity decreased with increasing carbon-ion dose in a range of 10 13 –10 16 ions/cm 2 . In particular, the activity drastically decreased when the carbon-ion dose was about 10 15 ions/cm 2 . From the PITCS measurements, it was found that the transport of holes toward the TiO 2 surface was retarded by carbon-ion dose. After hydrogen-plasma treatments, the activity was lower than that of as-prepared TiO 2 . For TiO 2 films grown by pulsed laser deposition and carried out hydrogen-plasma treatment, on the contrary, the activity was higher than that of pristine TiO 2 .