Antibacterial Activity of Photocatalytic Titanium Dioxide Thin Films with Photodeposited Silver on the Surface of Sanitary Ware

Abstract

The antibacterial activity of photocatalytic titanium dioxide (TiO 2 ) thin films with photodeposited silver on the surface of sanitary ware was studied. Samples were prepared by coating a TiO 2 sol that was calcined at 8801-9801C and photodeposited with silver ions onto the glazed layer of the sanitary ware. The relationships between the antibacterial activity and the fabrication conditions were investigated by X-ray diffractometry, scanning electron microscopy, and colorimetry. The phase of TiO 2 identified in the thin films was a mixture of anatase and rutile. The amount of rutile phase increased as the calcination temperature increased, and grain growth of the TiO 2 particles was observed. The activity was dependent on the TiO 2 thickness, the calcination temperature, and the amount of silver. These results suggest that the antibacterial activity was strongly affected by the amount of anatase in the thin films. 9801C for 1 h in a muffle furnace (Model FP-31, Yamato Science Company, Ltd., Tokyo, Japan). Sample tiles with a TiO 2 thin-film coating on the glaze were obtained. 95J ournal

Highly bioactive silver and silver/titania composite films grown by chemical vapour deposition

“…Sokmen [29] et al showed that addition of AgNO 3 to anatase (form of TiO 2 ) enhanced the photocatalytic activity and enhanced the killing of Escherichia coli in suspension. Ag enhanced the biocidal activity of photo-deposited silver on glazed sanitary ware [30] . The biocidal activity depended on thickness of the TiO 2 film, the amount of Ag and calcination temperature.…”

Synthesis of High-Temperature Stable Anatase TiO2 Photocatalyst

“…[16][17][18] Phase transition to rutile is non-reversible due to the greater thermodynamic stability of rutile phase. [19][20] Researchers at Toto Ltd. recently reported 21 a method to produce photoactive titania-Ag coatings on ceramic materials. The composition contains up to 7% anatase present at 900 °C.…”

“…The composition contains up to 7% anatase present at 900 °C. 21 Any improvement in the anatase phase composition at these high temperatures is expected to show a higher photocatalytic activity. 21 Conventionally metal oxide doping is used to extend the anatase to rutile transformation temperature above 700 ºC.…”

“…21 Any improvement in the anatase phase composition at these high temperatures is expected to show a higher photocatalytic activity. 21 Conventionally metal oxide doping is used to extend the anatase to rutile transformation temperature above 700 ºC. [22][23][24][25][26] Various metal oxide dopants such as Al 2 O 3 , NiO, SiO 2 , ZrO 2 , ZnO and Sb 2 O 5 have already been studied to assess the effect on both anatase to rutile transformation and alteration of modification on textural properties of titania.…”

One-Pot Synthesis of Anionic (Nitrogen) and Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts

“…Many proposed innovative and commercial applications for photocatalytically active stable titania-coated materials such as bathroom tiles, sanitary wares, and selfcleaning glass for the control of organic contaminants require high processing temperatures and hence high-temperature stability. 2,11,12 High consumer demand is projected for these materials. To date most of the work reported to improve the thermal stability of anatase titania utilizes metal ion doping.…”