Innovative photocatalyst (FeOx–TiO2): transients induced by femtosecond laser pulse leading to bacterial inactivation under visible light. Issue 123 (26th November 2015)

• Record Type: Journal Article
• Authors: Rtimi, S.; Sanjines, R.; Kiwi, J.; Pulgarin, C.; Bensimon, M.; Khmel, I.; Nadtochenko, V.
• Is Part Of: RSC advances. Volume 5:Issue 123(2015)
• Page Start: 101751
• Page End: 101759
• Publication Date: 2015-11-26
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra18960h
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : This study reports the photosensitizing effect/mechanism of FeO x under visible light irradiation and charge transfer to TiO2 on FeO x –TiO2 cosputtered film. Abstract : This study reports the photosensitizing effect/mechanism of FeO x under visible light irradiation and charge transfer to TiO2 on FeO x –TiO2 cosputtered film. The transients which were photo-induced by femto-second laser pulses at 545 nm (25 fs) were identified, in addition to the concomitant bleaching bands at <440 nm. Electron trapping at 150 fs was observed to compete with electron–hole recombination. A regularized inverse Laplace transform of the transient decay kinetics was worked out to determine the lifetime of the transients. About 50% of the charge carriers recombined within 500 fs, less than 50% of the charges recombined within 25 ps and a small percentage remained trapped. The transient decay within 500 ps did not decay to zero. This is the evidence for the photo-induced charges in FeO x –TiO2 leading subsequently to bacterial inactivation in the minute range. The second part of this study addresses the details of the FeO x –TiO2 –PE photocatalyst performance during E. coli inactivation under solar light irradiation. The bacterial inactivation kinetics was similar under solar or visible light irradiation (>400 nm). This observation unexpectedly confirms the role of FeO x absorbing light in the visible region. The important role of TiO2 is reported, leading to bacterial inactivation in the FeO x –TiO2 co-sputtered films.