Bactericidal performance of visible-light responsive titania photocatalyst with silver nanostructures.
BACKGROUND
Titania dioxide (TiO(2)) photocatalyst is primarily induced by ultraviolet light irradiation. Visible-light responsive anion-doped TiO(2) photocatalysts contain higher quantum efficiency under sunlight and can be used safely in indoor settings without exposing to biohazardous ultraviolet light. The antibacterial efficiency, however, remains to be further improved.


RESULTS
Using thermal reduction method, here we synthesized silver-nanostructures coated TiO(2) thin films that contain a high visible-light responsive antibacterial property. Among our tested titania substrates including TiO(2), carbon-doped TiO(2) [TiO(2) (C)] and nitrogen-doped TiO(2) [TiO(2) (N)], TiO(2) (N) showed the best performance after silver coating. The synergistic antibacterial effect results approximately 5 log reductions of surviving bacteria of Escherichia coli, Streptococcus pyogenes, Staphylococcus aureus and Acinetobacter baumannii. Scanning electron microscope analysis indicated that crystalline silver formed unique wire-like nanostructures on TiO(2) (N) substrates, while formed relatively straight and thicker rod-shaped precipitates on the other two titania materials.


CONCLUSIONS
Our results suggested that proper forms of silver on various titania materials could further influence the bactericidal property.
Wong
Ming-Show
MS
Department of Materials Science and Engineering, National Dong-Hwa University, Hualien, Taiwan.
Sun
Der-Shan
DS
Chang
Hsin-Hou
HH
D040981:Acinetobacter baumannii / Q000187:drug effects; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D004926:Escherichia coli / Q000187:drug effects; D008027:Light; D049329:Nanostructures / Q000737:chemistry*; D055668:Photochemical Processes; D012834:Silver; D013211:Staphylococcus aureus / Q000187:drug effects; D013297:Streptococcus pyogenes / Q000187:drug effects; D014025:Titanium / Q000528:radiation effects*
D000900:Anti-Bacterial Agents; C009495:titanium dioxide; D012834:Silver; D014025:Titanium
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