Antibacterial performance of photocatalyst thin film fabricated by defection effect in visible light

Abstract We have developed a new photocatalyst thin film that has strong antibacterial action in visible light. In this study the radiofrequency (RF) sputter technique was used to deposit a defective titanium dioxide (TiO x , x < 2) photocatalyst thin film (120 nm thickness) on glass and steel substrates. In the ultraviolet (UV)-visible spectrum analysis, the defective TiO x thin film was found to generate the red shift effect. To determine whether the defective TiO x thin film has antibacterial ability under visible light, we designed a series of experiments according to the Japanese Industrial Standards (JIS) Committee standard for testing antibacterial performance and for exploring the impact of surface roughness of substrate. Our results show that the antibacterial performance rate against Escherichia coli could reach 99.99% in visible light. We also proved that the coating technology can be applied effectively to surfaces with different degrees of roughness. It is suitable for protecting both human health and the natural environment.

[1]  A. Maldotti,et al.  Photocatalysis with organized systems for the oxofunctionalization of hydrocarbons by O2. , 2002, Chemical reviews.

[2]  Y. Konishi,et al.  A patterned TiO(2)(anatase)/TiO(2)(rutile) bilayer-type photocatalyst: effect of the anatase/rutile junction on the photocatalytic activity. , 2002, Angewandte Chemie.

[3]  Hideki Kato,et al.  Visible-Light-Response and Photocatalytic Activities of TiO2 and SrTiO3 Photocatalysts Codoped with Antimony and Chromium , 2002 .

[4]  K. Domen,et al.  LaTiO2N as a visible-light (≤600 nm)-driven photocatalyst (2) , 2003 .

[5]  R. Asahi,et al.  Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides , 2001, Science.

[6]  A. Fujishima,et al.  Electrochemical Photolysis of Water at a Semiconductor Electrode , 1972, Nature.

[7]  R. P. Noceti,et al.  New developments in the photocatalytic conversion of methane to methanol , 2000 .

[8]  J. Yates,et al.  Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results , 1995 .

[9]  M. Imai,et al.  A novel hydrogen-evolving photocatalyst InVO4 active under visible light irradiation , 2002 .

[10]  Hironori Arakawa,et al.  Direct splitting of water under visible light irradiation with an oxide semiconductor photocatalyst , 2001, Nature.

[11]  D. Meissner,et al.  Visible-light detoxification and charge generation by transition metal chloride modified titania. , 2000, Chemistry.

[12]  Shawn Decker,et al.  Nanocrystals as Stoichiometric Reagents with Unique Surface Chemistry , 1996 .