Structural Characterization and Photocatalytic Activity of Hydrothermally Synthesized Mesoporous TiO2 for 2,4,6-Tribromophenol Degradation in Water

Well defined mesoporous TiO2 (M-TiO2) nanocrystallites were prepared by the hydrothermal method using polypropylene glycol (PPG) as template. The method differs from traditional methods in the use of an acetic acid aqueous solution instead of the conventional hydrolysis inhibitors and acid catalysts. The morphology and microstructures of M-TiO2 were characterized by X-ray diffraction, thermogravimetric and differential thermogravimetric, scanning electron microscopy, and nitrogen adsorption-desorption. The effects of the synthesis process, template reagent content, and calcination temperature on the microstructure and photocatalytic activity were investigated. The relationship between the microstructure of M-TiO2 and its photocatalytic activity was studied by the photocatalytic degradation of 2,4,6-tribromophenol in water under UV irradiation. M-TiO2 with a regular channel structure, large pore size, and high specific surface area was successfully synthesized. The M-TiO2 synthesized by the hydrothermal method and calcined at 400 °C that used a PPG content of 20% gave the highest photocatalytic activity, and completely degraded 100 μmol/L 2,4,6-tribromophenol within 1 h.