Abstract: Mesoporous TiO₂ (MS-TiO₂) spheres were prepared by a sol-gel assisted hydrothermal method using double-surfactant (PEG and F127) as templates. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermal gravimetry, and N₂ adsorption-desorption were used for catalyst structural characterization. Phenol was used as a model compound for photocatalytic activity test. The results showed that MS-TiO₂ spheres with uniform diameter of 200–300 nm, which was composed by 15–20 nm of TiO₂ crystals, can be obtained. Maximum specific surface area as high as 106.9 m²/g, together with pore diameter of 6.5–12.6 nm and pore volume of 0.21 cm³/g can be achieved under the optimum conditions. With increasing calcination temperature, specific surface area and pore volume of MS-TiO₂ decreased, and pore diameter enlarged. Double templates can form a more stable spherical micelle, inhibit the growth and particle aggregation of TiO₂ precursor and promote its self-assembly into spherical structure. MS-TiO₂ prepared at 500 °C exhibited the highest activity with the phenol degradation of 86.4%, which is about 1.3 times that of TiO₂ without templates.

Key words: double template, titanium dioxide, mesopore, sphere, surfactant, phenol