Effect of Block Copolymer Additives on the Structure and Crystallinity of Nanostructured Mesoporous TiO2

In this study, nanostructured mesoporous TiO2 was prepared by sol-gel process, and the synthesis was accomplished by using block copolymer as the structure-directing agent and TiCl4 as the inorganic precursor. TGA, XRD, SAXS, TEM and N2 adsorptiondesorption isotherms were used to characterize the microstructure, pore size, and pore structure after calcination. The powders were found to have a wormhole-like pore structure after calcination. When the addition of block copolymer increased from 0.1 to 1.5 g, the specific surface areas increased from 113.23 to 284.75 m2/g, but the average pore sizes decreased from 7.4 to 4.8 nm, and the average crystallite sizes decreased from 9.0 to 5.5 nm after being calcinated at 300 °C for 5 h. These results show that the mesostructure and crystallinity of TiO2 can be controlled by the additive concentrations of block copolymer.