Hirotsugu Kishimoto

Photocatalytic activity of titanium oxide prepared by liquid phase deposition (LPD)

Titanium oxide powder and thin films were prepared from an (NH4)2TiF6 aqueous solution upon addition of boric acid in a process denoted as liquid phase deposition (LPD). In this process, titanium oxide powder and films were formed by the chemical equilibrium reaction between titanium fluoro-complex ions and metal oxide in the aqueous solution. The prepared powder and deposited films showed some features which differed from titanium oxide prepared from titanium alkoxide. The prepared powder and the deposited films included anatase (TiO2) and showed photocatalytic activity without prior calcination. The decomposition rate of CH3CHO reached a maximum when the powder or films were calcined at 300 °C. The LPD process enabled a uniform layer of TiO2 film to form homogeneously on the entire surface of glass wool. The prepared TiO2 contained fluorine and nitrogen. The amount of these impurities was reduced upon calcination.