Photocatalytic and antibacterial activity of TiO₂and Au/TiO₂nanosystems

Abstract

This work focuses on the photocatalytic performances and antibacterial \nactivity of TiO2 and Au/TiO2 nanosystems. While the former are obtained by \na sol–gel route, the latter are synthesized by an innovative hybrid \nRF-sputtering/sol–gel approach, followed by ex situ annealing in air up to \n600 ◦C. Important information on nanoparticle size, shape and distribution is \nobtained by the combined use of glancing incidence x-ray diffraction \n(GIXRD) and field emission-scanning electron microscopy (FE-SEM). \nSubsequently, the photocatalytic performances of the obtained nanosystems \nin the decomposition of the azo-dye Plasmocorinth B and their antibacterial \nactivity in the elimination of Bacillus subtilis are illustrated and discussed in \ncomparison with films obtained from standard Degussa P25 powders. The \nobtained results show a significant dependence of the functional \nperformances on the system’s compositional, structural and morphological \nproperties. In particular, the dispersion of gold nanoparticles on the TiO2 \nmatrix has a beneficial influence on the azo-dye photodegradation, whereas \nthe antimicrobial activity of Au/TiO2 films is retarded with respect to pure \nTiO2.