Preparation and characterization of Au-dispersed TiO2 thin films by a liquid-phase deposition method

Au-dispersed TiO2 (anatase) thin films were prepared by a novel method, liquid-phase deposition (LPD). The deposited films were characterised by XRD, XPS, TEM, ICP and UV-Vis absorption spectroscopy. The results showed that the TiO2 thin film containing AuIII ions was formed from a mixed solution of ammonium hexafluorotitanate, boric acid and tetrachloroauric acid. Heat treatment above 200 C of the deposited film under flowing air produced dispersed Au metal particles, accompanied by the crystallisation of TiO2 as a matrix. The mean particle size of the dispersed Au particles was about 15 nm. The optical absorption band due to the surface plasmon resonance of the dispersed Au particles shifted towards longer wavelengths with increasing heat-treatment temperature. 13 refs.