Preparation, characterization and photocatalytic properties of TiO 2 nanostructured spheres synthesized by the Sol–Gel method modified with ethylene glycol

Monodispersed nanostructured TiO 2 spheres were obtained by the Sol–Gel method modified with ethylene glycol. The sample morphology and surface textural properties were characterized by X-ray diffraction (XRD), N 2 -physisorption, scanning electron microscopy (SEM), transmission electron microscopy ( TEM ) , thermogravimetric analysis (TGA) and diffuse reflectance spectroscopy (DRS). The SEM image showed spheres with sizes ranging from 600 to 700 nm. In addition, HRTEM micrographs reveal hexagonal grains slightly elongated (20 nm). The powders present a BET surface area of 116 m 2 g −1 . Samples without thermal treatment and those treated at 400 °C both showed characteristic reflections of the anatase phase. The photocatalytic activity of the prepared TiO 2 spheres was determined by degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution. Kinetics parameters have displayed than the nanostructured material present a reaction half-life time of 30 min and it was two times faster than commercial TiO 2 (P25).