Optical properties and reactions of radiation induced tich electrons in aqueous colloid solutions

This work involves an experimental study of the optical properties of excess electrons in solvated TiO₂ nanoparticles. The excess electrons were produced by y irradiation of deaerated 2-propanol solutions containing TiO₂ nanoparticles in acidic pH. The irradiation produced propanol radicals and hydrated electrons, which react with TiO₂ sols and produce the blue color of excess TiO₂ electrons. Results are provided for the maximum loading of electrons on the TiO₂ nanoparticles for both Q-particles and large nanocrystallites, and for the extinction coefficients, which were determined by titration. Discussion of the electron spectra in the light of earlier work is presented. In addition, we find that the high local concentration of electrons enables reduction of H₂O₂2 and ClU₄^- by simultaneous two-electron transfer.