title: Additional effects of silver nanoparticles on bactericidal efficiency depend on calcination temperature and dip-coating speed.
abstract: There is an increasing interest in the application of photocatalytic properties for disinfection of surfaces, air, and water. Titanium dioxide is widely used as a photocatalyst, and the addition of silver reportedly enhances its bactericidal action. However, the synergy of silver nanoparticles and TiO(2) is not well understood. The photocatalytic elimination of Bacillus atrophaeus was examined under different calcination temperatures, dip-coating speeds, and ratios of TiO(2), SiO(2), and Ag to identify optimal production conditions for the production of TiO(2)- and/or TiO(2)/Ag-coated glass for surface disinfection. Photocatalytic disinfection of pure TiO(2) or TiO(2) plus Ag nanoparticles was dependent primarily on the calcination temperature. The antibacterial activity of TiO(2) films was optimal with a high dip-coating speed and high calcination temperature (600°C). Maximal bacterial inactivation using TiO(2)/Ag-coated glass was also observed following high-speed dip coating but with a low calcination temperature (250°C). Scanning electron microscopy (SEM) showed that the Ag nanoparticles combined together at a high calcination temperature, leading to decreased antibacterial activity of TiO(2)/Ag films due to a smaller surface area of Ag nanoparticles. The presence of Ag enhanced the photocatalytic inactivation rate of TiO(2), producing a more pronounced effect with increasing levels of catalyst loading.
authors: Department of Preventive Environment and Nutrition, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima City, Tokushima, Japan.
authors: Nhung Thi Tuyet
authors: NT
authors: Le
authors: Hirofumi
authors: H
authors: Nagata
authors: Mutsumi
authors: M
authors: Aihara
authors: Akira
authors: A
authors: Takahashi
authors: Toshihiro
authors: T
authors: Okamoto
authors: Takaaki
authors: T
authors: Shimohata
authors: Kazuaki
authors: K
authors: Mawatari
authors: Yhosuke
authors: Y
authors: Kinouchi
authors: Masatake
authors: M
authors: Akutagawa
authors: Masanobu
authors: M
authors: Haraguchi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001407:Bacillus / Q000187:drug effects* / Q000528:radiation effects; D002384:Catalysis; D004202:Disinfectants / Q000494:pharmacology; D005898:Glass / Q000737:chemistry; D006358:Hot Temperature; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D010777:Photochemistry; D012822:Silicon Dioxide / Q000494:pharmacology; D012834:Silver / Q000494:pharmacology*; D013997:Time Factors; D014025:Titanium / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D000900:Anti-Bacterial Agents; D004202:Disinfectants; C009495:titanium dioxide; D012834:Silver; D012822:Silicon Dioxide; D014025:Titanium