Loading...

Lasting antibacterial activities of Ag-TiO2/Ag/a-TiO2 nanocomposite thin film photocatalysts under solar light irradiation

Akhavan, O ; Sharif University of Technology | 2009

1318 Viewed
  1. Type of Document: Article
  2. DOI: 10.1016/j.jcis.2009.03.018
  3. Publisher: 2009
  4. Abstract:
  5. Photodegradation of Escherichia coli bacteria in presence of Ag-TiO2/Ag/a-TiO2 nanocomposite film with an effective storage of silver nanoparticles was investigated in the visible and the solar light irradiations. The nanocomposite film was synthesized by sol-gel deposition of 30 nm Ag-TiO2 layer on ∼200 nm anatase(a-)TiO2 film previously doped by silver nanoparticles. Both Ag/a-TiO2 and Ag-TiO2/Ag/a-TiO2 films were transparent with a SPR absorption band at 412 nm. Depth profile X-ray photoelectron spectroscopy showed metallic silver nanoparticles with diameter of 30 nm and fcc crystalline structure were self-accumulated on the film surface at depth of 5 nm of the TiO2 layer and also at the interface of the Ag-TiO2 and a-TiO2 films (at depth of 30 nm). Both OH- bounds and H2O contents were concentrated on the film surface and at the interface, as a profit in releasing more ionic (not metallic) silver nanoparticles. Antibacterial activity of the nanocomposite film against E. coli bacteria was 5.1 times stronger than activity of the a-TiO2, in dark. Photo-antibacterial activity of the nanocomposite film exposed by the solar light was measured 1.35 and 6.90 times better than activity of the Ag/a-TiO2 and a-TiO2, respectively. The main mechanism for silver ion releasing was inter-diffusion of water and silver nanoparticles through pores of the TiO2 layer. Durability of the nanocomposite film was at least 11 times higher than the Ag/a-TiO2 film. Therefore, the Ag-TiO2/Ag/a-TiO2 photocatalyst can be nominated as one of the effective and long-lasting antibacterial nanocomposite materials. © 2009 Elsevier Inc. All rights reserved
  6. Keywords:
  7. Solar light ; Titanium oxide photocatalyst ; Absorption band ; Anti-bacterial activity ; Crystalline structure ; Depth profile ; E. coli ; Escherichia coli bacteria ; Film surfaces ; Inter-diffusion ; Long lasting ; Metallic silver ; Nanocomposite film ; Nanocomposite materials ; Nanocomposite thin films ; Silver ions ; Silver nanoparticles ; Sol-gel deposition ; Solar light irradiation ; TiO ; Bacteriology ; Gelation ; Ionization of liquids ; Irradiation ; Metal ions ; Nanocomposites ; Nanoparticles ; Organic polymers ; Photocatalysis ; Titanium oxides ; Metal ion ; Metal nanoparticle ; Nanocomposite ; Nanoparticle ; Titanium dioxide ; Water ; Antibacterial activity ; Composite material ; Controlled study ; Crystal structure ; Diffusion ; Film ; Gel ; Light irradiance ; Nonhuman ; Photodegradation ; Priority journal ; Solar energy ; Solar radiation ; Solid ; Synthesis ; Water content ; X ray photoelectron spectroscopy ; Anti-Bacterial Agents ; Escherichia coli ; Light ; Microbial Viability ; Nanostructures ; Photochemical Processes ; Radiation ; Silver ; Solar System ; Titanium ; X-Ray Diffraction
  8. Source: Journal of Colloid and Interface Science ; Volume 336, Issue 1 , 2009 , Pages 117-124 ; 00219797 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0021979709002999?via%3Dihub