TiO2 thin films prepared from aqueous solution and their sterilizing capability

A liquid phase deposition method (LPD) has been devised for the deposition of TiO2 thin films on glass at a low temperature. The substrates were immersed in a diluted homogeneous aqueous solution which was prepared by mixing equal volumes of ammonium hexauorotitanate and boric acid solution. The TiO2 thin films obtained were well-adhered, homogenous and colored by interference of reflected light. XRD indicated TiO2 thin films showed a high degree of crystallinity and the crystal phase observed was anatase. SEM experiments showed that the films are formed by small crystallites having linear dimensions under 50 nm. Their thickness was in the range of 100 similar to 300 nm. The sterilizing experiment of S. aureus and E. coli showed that TiO2 thin films have excellent sterilizing activity. The optimum conditions of the films were with heat treatment at 400 degrees C where their sterilizing percentage reached over 99% after 24h.