X-ray induced photocatalytic reaction on TiO

Tamura, Kazuhisa   ; Oko, Yoshihisa*; Tatsuma, Tetsu*; Mizuki, Junichiro

We measured a cyclic voltammogram of TiO under intermittent X-ray irradiation and time courses of the rest potential under X-ray irradiation and in the dark. Both the oxidation current and the negative shift of the rest potential were observed only under irradiation, indicating that the electron-hole pair formation and the photocatalytic reaction occur under X-ray irradiation. We also measured action spectra of the photocurrent and photopotential. It was found that both the photocurrent and photopotential with very high quantum efficiency (400%) were observed above Ti-K edge and the fine structure of action spectra had the same structure of XANES spectrum, indicating that electrons in the valence band are excited during the relaxation process of excited inner shell electrons of Ti.