Synthesis of mesoporous titania with high photocatalytic activity by nanocrystalline particle assembly

A mesoporous TiO2 with high photocatalytic activity was synthesized by assembling nanocrystalline particles using dodecylamine (DDA) as organic linkers. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), nitrogen adsorption–desorption isotherms and thermogravimetry-differential thermal analysis (TG-DTA). Low-angle XRD and TEM confirmed that the mesoporous TiO2 had a wormhole-like structure. Nitrogen adsorption–desorption isotherm showed products retained mesoporosity with a narrow pore size distribution (2.8–4.0 nm) and high surface areas (104.4–346.0 m2/g) to 673 K. TG-DTA analysis revealed that the surfactant had been removed partly in as-synthesized samples. The pH value affected the order of mesoporous structure. The ordered mesoporous structure would not retain at pH = 14. All calcined mesoporous TiO2 showed high photocatalytic activities on photodecomposition of cationic dye X-GL.