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 0degrees 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 N-2 and O-2. 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 N-2 and O-2 from NO.