Sol-gel synthesis of mesoporous hollow titania microspheres for photodegradation of 4-chlorophenol

Mesoporous titania (TiO2) hollow microspheres have been prepared by sol-gel method and characterized by XRD, Raman, FTIR, N-2 adsorption-desorption study, FESEM, TEM and UV-DRS. The FESEM images reveal hollow spherical shaped particles of size 2-4 mu m. The BET surface area, total pore volume and average pore diameter of 400 degrees C-treated sample are found to be 74.52 m(2) g(-1), 0.23 cm(3) g(-1) and 12.37 nm, respectively. The band gap energy of the product is calculated as 3.06 eV. The prepared TiO2 hollow spheres show similar to 90% photodegradation of the water pollutant, 4-chlorophenol, within 1 h. The photocatalytic reaction shows pseudo-first order reaction with a rate constant of 0.027 min(-1). The photocatalytic experiments repeated for another three cycles showed no significant changes in the k (min(-1)) values, indicating the potential reusability of the material