Synthesis of bi-porous TiO2 with crystalline framework using a double surfactant system

A mesoporous TiO2 with crystalline framework was synthesized by nanocrystalline particle assembly using a double surfactant system. Hydrothermal treatment was adopted in order to improve the crystallinity of mesoporous framework. The XRD patterns, HRTEM and TEM images indicate that the as-synthesized product is mesoporous structure and the pore wall is crystalline structure. Nitrogen adsorption–desorption isotherm reveals that there is the bi-porous structure in the sample calcined at 523 K. A controlled calcination process using a slow and constant heating rate was adopted so that the mesoporous structure of the sample could be retained to 673 K.