Sol–gel derived silver-incorporated titania thin films on glass: bactericidal and photocatalytic activity

• Published in: Journal of sol-gel science and technology Vol. 59; no. 2; pp. 228 - 238
• Main Authors: Akgun, Betul Akkopru, Wren, Anthony W., Durucan, Caner, Towler, Mark R., Mellott, Nathan P.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.08.2011; Springer; Springer Nature B.V
• Subjects: Bacteria; Catalysis; Catalytic activity; Ceramics; Chemistry; Chemistry and Materials Science; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Composites; Exact sciences and technology; General and physical chemistry; Glass; Glass substrates; Illumination; Inorganic Chemistry; Light; Materials Science; Nanoparticles; Nanotechnology; Natural Materials; Optical and Electronic Materials; Organic chemistry; Original Paper; Photocatalysis; Photochemistry; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Process parameters; Roasting; Silica glass; Silicon dioxide; Silver; Sol-gel processes; Spin coating; Staphylococcus epidermidis; Stearic acid; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Thin films; Titanium dioxide; Antimicrobial; Photocatalytic; Antibacterial; Titania; Thin film; Silver nanoparticle; Binary compound; Film; Nanoparticle; Spin; Glass; Silica; Assay; Degradation; Carboxylic acid; Stearic acid; Diffusion; Structure; Disk; Release; Photocatalysis; Transition element compounds; Agar; Ions; Transition metal; Substrate; Silver; Heterogeneous catalysis; Saturated fatty acid; Sol gel process; Distribution; Antibacterial agent; Titanium oxide
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-011-2488-6

Titanium dioxide (TiO 2 ) and silver-containing TiO 2 (Ag-TiO 2 ) thin films were prepared on silica pre-coated float glass substrates by a sol–gel spin coating method. The bactericidal activity of the films was determined against Staphylococcus epidermidis under natural and ultraviolet (UV) illumination by four complementary methods; (1) the disk diffusion assay, (2) UV-induced bactericidal test, (3) qualitative Ag ion release in bacteria inoculated agar media and (4) surface topographical examination by laserscan profilometry. Photocatalytic activity of the films was measured through the degradation of stearic acid under UV, solar and visible light conditions. The chemical state and distribution of Ag nanoparticles, as well as the structure of the TiO 2 matrix, and hence the bactericidal and photocatalytic activity, is controlled by post-coating calcination treatment (100–650 °C). Additionally, under any given illumination condition the Ag-incorporated films were found to have superior bactericidal and photocataltyic activity performance compared to TiO 2 thin films. It is shown that with optimized thin film processing parameters, both TiO 2 and Ag-TiO 2 thin films calcined at 450 °C were bactericidal and photocatalytically active.