TiON and TiON-Ag sputtered surfaces leading to bacterial inactivation under indoor actinic light

Suggested reaction mechanism fir the visible light photo-induced electron injection by Ag2O into TiO2. [Display omitted] ► This study present in detail TiON and TiON-Ag films effective in Escherichia coli inactivation under actinic light. ► The magnitude of the optical absorption of TiON films was s...

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Veröffentlicht in:Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2013-03, Vol.256, p.52-63
Hauptverfasser: Rtimi, Sami, Baghriche, Oualid, Sanjines, Rosendo, Pulgarin, Cesar, Bensimon, Michael, Kiwi, John
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Sprache:eng
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Zusammenfassung:Suggested reaction mechanism fir the visible light photo-induced electron injection by Ag2O into TiO2. [Display omitted] ► This study present in detail TiON and TiON-Ag films effective in Escherichia coli inactivation under actinic light. ► The magnitude of the optical absorption of TiON films was seen to be in direct relation to the E. coli inactivation kinetics. ► A mechanism is suggested for E. coli inactivation related to interfacial charge transfer between two oxides. This study reports the details Escherichia coli inactivation kinetics on TiON and TiON-Ag films sputtered on polyester by direct current reactive magnetron sputtering (DC) and pulsed magnetron sputtering (DCP) in an Ar/N2/O2 atmosphere. The use of TiON leads to bacterial inactivation avoiding leaching of Ag. The surface of TiON and TiON-Ag was characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), electron microscopy (EM), X-ray fluorescence (XRF) and contact angle (CA) measurements. Evidence for the photocatalyst self-cleaning after the bacterial inactivation was shown by XPS, contact angle (CA) and the Zetasizer zeta-potential of the proteins. The photo-induced charge transfer from Ag2O and TiO2 is discussed considering the relative positions of the electronic bands of the two oxides. An interfacial charge transfer mechanism (IFCT) for the photo-induced electron injection is suggested. The most suitable TiON coating sputtered on polyester was 70nm thick and inactivated E. coli within 120min under low intensity visible/actinic light (400–700nm, 4mW/cm2). TiON-Ag sputtered catalysts shortened E. coli inactivation to ∼55min, since Ag accelerated bacterial inactivation due to its disinfecting properties. Evidence is presented for the repetitive performance within short times of the TiON and TiON-Ag polyester under low intensity visible light.
ISSN:1010-6030
1873-2666
DOI:10.1016/j.jphotochem.2013.02.005