Plasma deposition of hybrid nanocomposite coatings from aerosol containing TiO2 and AgNO3

TiO2 nanocomposites are widely studied for the photocatalytic degradation of organic pollutants. Coupling TiO2, an n-type semiconductor, with an electron-sink co-catalyst effectively reduces electron-hole recombination, thereby enhancing photocatalytic efficiency. In this study, photoactive nanocomposite coatings were developed for the first time by depositing TiO2 nanoparticles and AgNO3 in various ratios within a siloxane matrix via aerosol-assisted atmospheric pressure plasma deposition. The photocatalytic activity of these coatings was assessed by monitoring the discoloration of a solution of methylene blue under UV irradiation (λ = 254 nm) using UV–Vis spectroscopy, with recyclability tested over three cycles. The chemical composition, structure, and morphology have been also assessed. The beneficial effect of the silver addition was more evident for coatings deposited with a low amount of TiO2. Moreover, repeated use of the photocatalytic coatings led to enhanced performance, due to partial matrix degradation and photoreduction of Ag(I) to Ag(0), as confirmed by X-Ray Photoelectron Spectroscopy.