The application of ultrasonic assisted sol-gel method at various % amplitude ultrasonic energy (AS) and reaction time of 40- 80% and 1-4 hrs, respectively for preparation of nano-TiO2 crystals was carried out. Synthesized nano-TiO2 was characterized for its structure, particle size, morphology, adsorption energy, and functional groups using X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), ultraviolet-visible (UV-VIS) and Fourier transform infrared (FTIR) spectrophotometries. A best nano-TiO2 crystal (6.8 nm), was observed at 40% AS for 1 hr showed the highest methylene blue degradation yield of 80%.

Keywords: The ultrasonic assisted sol-gel method, the nano-TiO2 photocatalysts, Photocatalytic degradation.