Effect of AC electric fields on the aerosol assisted chemical vapour deposition growth of titanium dioxide thin films

Titanium dioxide thin films were deposited on fluorine doped tin oxide glass substrates from the electric field assisted aerosol chemical vapour deposition reaction of titanium isopropoxide in toluene at 450 °C. The deposited films were characterised using scanning electron microscope, X-ray diffraction, Raman spectroscopy and UV/Vis spectroscopy. The photoactivity and hydrophilicity of deposited films were also analysed using an intelligent dye-ink test and water-contact angle measurements, respectively. The characterisation work revealed that the incorporation of electric fields influenced the film microstructure, preferential orientation and photocatalytic properties of titanium dioxide thin films. X-ray diffraction revealed that the application electric fields led to a change in the film preferential orientation from (200) to (004) and (211) planes depending on the applied field strength. The photocatalytic activity was calculated from the time needed by the films to degrade 90% of the dye-ink initial concentration (t90). It was observed that all films prepared with an applied electric field showed increased photocatalytic activity compared to films produced with no electric field. The most photocatalytically active films had preferred orientation in the (004) plane.