Effect of water on the formation of nanostructured mesoporous titania

Abstract

Mesostructured titania was prepared by a sol-gel process and the main purpose of this study is to elucidate the effect of water on the crystal structure, specific surface area, pore size, and morphology of the material. We adopt the poly (alkylene oxide) triblock copolymer of F108 as a template to form mesoporous titania. The resulting mesoporous titania, calcined at 300 °C to remove the template, was composed of a crystalline titania matrix containing pure anatase nanocrystals and bicrystalline (anatase and rutile) nanocrystals for samples prepared with full ethanol and with an amount of water replacement, respectively, as shown by XRD, Raman and TEM investigations. The mesoporous titania was shown to have a high specific surface area of 565.4 m 2/g and the average pore diameter is 5.2 nm, with a pore volume of 0.76 cm 3/g after it is calcined at 300 °C with bicrystalline frameworks when the ethanol solvent is replaced with 25% water. These results show that the hydrolysis reactions have great significance, and this nanostructured material is of interest for photocatalysts, photoelectrochemical solar cells and other photonic devices.