Inhibiting Effect of Aluminosilicate Intermediate on Agglomeration and Phase Transition of TiO_2 Nanoparticles

By heating coal fly ash with hydroxide sodium solution, then hydrolysis, the aluminosil-icate intermediate (ASI) was prepared. Through the addition of ASI into the titanium sol obtained by using the sol-gel method, titanium-aluminosilicate (TiO2/ASI) composites were prepared, and then heat-treated at different temperatures. The formation process and phase transition of TiO2 nanocrystalline in the TiO2/ASI composites were characterized by X-ray diffraction and UV-Vis diffuse reflectance spectra. The results indicate that the agglomeration of TiO2 nanoparticles and their phase transition from anatase to rutile can be inhibited efficiently. The adsorption activity of methylene blue of the synthesized TiO2/ASI composites is higher than that of only aluminosilicate intermediate or TiO2 particles.