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, N2 adsorption-desorption study, FESEM, TEM and UV-DRS. The FESEM images reveal hollow spherical shaped particles of size 2–4 µm. The BET surface area, total pore volume and average pore diameter of 400 °C-treated sample are found to be 74.52 m2 g-1, 0.23 cm3 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 ~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