Preparation of highly crystalline mesoporous TiO2 by sol–gel method combined with two-step calcining process

Abstract

Mesoporous TiO2 samples, with large specific surface area and high crystallinity, were prepared by a sol–gel method using polyethylene glycol and polyacrylamide (PAM) as composite templates and by two-step calcining process (at 500—700 °C in nitrogen and 500 °C in air). As a comparison, the sample was prepared using same composite templates by one-step calcining process (at 500 °C in air). The samples were characterised by X-ray diffraction, transmission electron microscopy, N2 adsorption–desorption, and diffuse reflectance UV-visible absorption spectra. The results showed that when the samples were fabricated using two-step calcining process, they exhibited typical mesoporous structure, large specific surface area, and high crystallinity. The properties of samples were studied. The results showed that PAM accelerates gel rate. The crystallinity and specific surface areas of samples were increased by using two-step calcining process. Compared with the sample prepared using one-step calcining process, the visible light absorption of samples synthesised by the two-step calcining process was improved.