Osorio-Vargas, Paula A.Pulgarin, CesarSienkiewicz, AndrzejPizzio, Luis R.Blanco, Mirta N.Torres-Palma, Ricardo A.Petrier, ChristianRengifo-Herrera, Julian A.2012-03-082012-03-082012-03-08201210.1016/j.ultsonch.2011.11.013https://infoscience.epfl.ch/handle/20.500.14299/78514WOS:000300136100002Low-frequency ultrasound (LFUS) irradiation induces morphological, optical and surface changes in the commercial nano-TiO2-based photocatalyst, Evonik-Degussa P-25. Low-temperature electron spin resonance (ESR) measurements performed on this material provided the first experimental evidence for the formation of oxygen vacancies (V-o), which were also found responsible for the visible-light absorption. The V-o surface defects might result from high-speed inter-particle collisions and shock waves generated by LFUS sonication impacting the TiO2 particles. This is in contrast to a number of well-established technologies, where the formation of oxygen vacancies on the TiO2 surface often requires harsh technological conditions and complicated procedures, such as annealing at high temperatures, radio-frequency-induced plasma or ion sputtering.Visible-light responsive TiO2Low-frequency ultrasoundOxygen vacanciesElectron-Paramagnetic-ResTitanium-OxidesPhotocatalysisDepositionDefectsAnatasetext::journal::journal article::research article