Reversible Photoinduced Electron Transfer in T1O2 Rutile

Spectra were perfectly restored to the original one, showing that this photoinduced (ESR) spectral change is reversible. 

An O2 molecule attached to the oxygen vacancy site (b) forms a peroxide 02 ion by coordination with the two ions, in accord with theoretical studies [113]. When one electron is transferred from 02 to one of the two oxidized ions by visible-light illumination, the corresponding O—coordination is broken, and a pair of 02 (B) and species are concomitantly formed as observed. On the other hand, adsorption of O2 at the five-coordinate site (a) may generate 02 (A) by one-electron transfer from to the adsorbed O2 molecule. The paramagnetic 02 (A) species appears to be inactive under visible-light illumination. 

3 Electron Transfer in Mixed Phase ofAnatase and Rutile 

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