Oscillatory variation in yields of I2 and the reactivity of γ-irradiated TiO2 in KI solution

The reactivity of preheated and γ-irradiated TiO2 was observed in KI solution by studying the kinetics of liberation of I2. The rate of the reaction was found to be low. During irradiation -Ti4+-O2ad- and Ti3+- sites are produced which are reducing in nature and therefore very low yields of I2 are observed for low γ-doses. In further irradiation the reformation of -O-O-, peroxy linkages is proposed hence the observed higher yields. All the processes ultimately lead to an oscillatory variation in yields of I2 with γ-doses. (author) 5 refs