Triblock copolymer-templated synthesis of porous TiO2 and its photocatalytic activity

Mixed amorphous and anatase-type titania particles were synthesized using non-ionic triblock copolymer as surfactant template and TiOSO₄ as inorganic precursor through sol–gel process. The as-prepared materials were characterized by X-ray diffraction spectroscopy, scanning and transmission electron microscopy, specific surface area, Fourier-transformed infrared spectroscopy, and diffuse reflectance ultraviolet–visible spectroscopy. The template material could be easily removed by extracting with dichloromethane and was confirmed by infrared spectroscopy. X-ray diffraction pattern reveals the crystalline part of as-prepared product as a framework of anatase phase. From the N₂ adsorption–desorption analysis, the as-prepared sample has a surface area of 301 m²/g with pore size distribution narrowly centered around 6 nm. The photodegradation of indigo carmine including kinetics, effect of pH, and recyclability of the product were investigated. The photocatalytic results showed that the as-synthesized titania could efficiently degrade indigo carmine under ultraviolet irradiation and showed higher photocatalytic activity than the commercial Degussa P25–TiO₂.