High efficient photocatalyst of spherical TiO2 particles synthesized by a sol–gel method modified with glycol

•TiO2 spherical colloids are synthesized by sol–gel method modified with glycol.•The size of titania colloids range from 250 to 550 nm by varying the water amount.•The rate of hydrolysis is depressed with the increase of EO unit in glycol.•The calcinated TiO2 at 600 °C shows the highest photocatalytic activity.

Monodisperse spherical TiO2 particles were prepared by a sol–gel method modified with different glycols at room temperature and were calcined at different temperatures between 400 and 950 °C. The synthesized and calcined TiO2 powders were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TG). The TEM images showed particles with sizes ranging from 250 to 550 nm. XRD revealed the phase transition from anatase to rutile was around 600 °C for TiO2 particles. The photocatalytic activity of the prepared TiO2 particles was determined by degradation of methylene blue (MB) in aqueous solution under UV irradiation and the results showed that the photocatalytic activity of TiO2 particles strongly depended on the calcination temperature. Especially, the TiO2 powder calcined at 600 °C showed the highest photocatalytic activity benefiting from the mixture of anatase and rutile of TiO2.

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