Photoinduced superhydrophilic properties of Ti-B binary oxide thin films and their photocatalytic reactivity for the decomposition of NO.

Characterizations of Ti-B binary oxide thin films by means of various spectroscopic measurements have shown that Ti-B binary oxide thin films are formed by ultra fine TiO2 nanoparticles. A dramatic decrease in the contact angle of water droplets to 0 degree under ultraviolet (UV) light irradiation and a return to only half of its initial value under dark conditions were observed for the Ti-B binary oxide thin films. Moreover, ultraviolet irradiation of these thin film photocatalysts in the presence of NO led to photocatalytic decomposition of NO into N2 and O2. Especially when the Ti content was low, the size of the primary nanoparticles of the thin films was smaller and the photocatalytic reaction proceeded efficiently with a high selectivity for the formation of N2 and O2 from NO.