Ag−TiO₂ Nanoparticle Codoped SiO₂ Films on ZrO₂ Barrier-Coated Glass Substrates with Antibacterial Activity in Ambient Condition

Abstract

Anatase TiO₂ and Ag nanoparticles (NPs) codoped SiO₂ films were prepared by the sol−gel method. Proportionate amounts of 3-(glycidoxypropyl)trimethoxysilane (GLYMO), tetraethylorthosilicate (TEOS) and 3-(methacryloxypropyl)trimethoxysilane (MEMO) derived inorganic−organic silica sol, commercially available dispersed anatase TiO₂ NPs, and AgNO₂ were used to prepare the sols. The films were prepared on ZrO₂ (cubic) precoated soda-lime glass substrates by a single-dipping technique and heat-treated at 450 °C in air and H₂/Ar atmosphere to obtain hard, relatively porous, and transparent coatings of thickness >600 nm. The ZrO₂ barrier layer was previously applied on soda-lime glass to restrict the diffusion of Ag into the substrate. The Ag−TiO₂ NPs incorporated SiO₂ films were intense yellow in color and found to be fairly stable at ambient condition for several days under fluorescent light. These films show a considerable growth inhibition on contact with the gram negative bacteria E. coli.