The Interface Reaction between an Ag+-Doped TiO2 Film and Stainless Steel Substrate
Ag+-doped TiO2 films on stainless steel were prepared by a sol-gel method and their microstructures and compositions were studied with X-Ray Diffractometer, Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy. It was shown that Fe atoms in untreated stainless steel react with Ag+ in the TiO2 film and form FeTiO3, which has an acicular crystal form under SEM observation. As a result, Ag+ in the film is reduced to the silver atom, which degrades the antibacterial property of the film. However, after an oxidization of the substrate, a layer of ferric oxide is formed, which reacts with Fe atoms that would otherwise react with and reduce Ag+, and then forms FeTiO3. Thus, the penetration of Fe atoms is stopped and Ag+ in the anatase-structure TiO2 film is protected from the reduction, which enhanced antibacterial property of the film.
Wei Pan and Jianghong Gong
X. G. Ding, J. W. Gao, Q. H. Shen, J. X. Liu, L. Li, "The Interface Reaction between an Ag+-Doped TiO2 Film and Stainless Steel Substrate", Key Engineering Materials, Vols. 336-338, pp. 1559-1562, 2007