EFFECT OF ULTRASONIC IRRADIATION TIME AND AMPLITUDE VARIATION ON TiO2 PARTICLES

Abstract

A novel sonochemical method has been applied to directly prepare TiO₂ colloid. TiO₂ colloids were synthesized by using titanium tetraisopropoxide as a precursor of titanium. Ultrasonic irradiation was applied during the reaction process of the reactants. Several variable parameters of ultrasonic irradiation were applied upon the TiO₂ colloid (ultrasonic irradiation time and amplitude).Then, TiO₂ colloids were used to fabricate TiO₂ thin film via dip coating process. The TiO2 thin films were then calcined at 500 °C for 2 hours. The physical and chemical properties of TiO₂ thin film were studied using different techniques of characterization such as X-ray diffraction (XRD), Transmission Electron Microscope (TEM), and UV-Vis spectrophotometer. It seems that increasing ultrasonic irradiation amplitude leads to the formation of bigger TiO₂ particles in the colloid as confirmed by the shift of absorption edge towards shorter wavelength and TEM pictures. The efficiency of TiO₂ thin film photocatalyst was evaluated on degradation of methylene blue.