Thermal stability of anatase TiO2 aerogels

Titanium dioxide (TiO2) aerogels were prepared with sol-gel ambient pressure drying method by using titanium tetrachloride (TiCl4) as precursor and tetraethoxysilane as modifier, calcinated at different temperature and characterized by X-ray diffraction, transmission electron microscopy and small angle X-ray scattering. The results showed that the TiO2 aerogels remained amorphous under 500 degrees C, changed to anatase from 600 degrees C and further changed to rutile from 900 degrees C. Between 60 degrees C and 500 degrees C, the primary particles within the samples concentrated mainly upon small sizes, enlarged and diverged remarkably above 600 degrees C. The crystalline grains grew and agglomerated with the rise of the calcination temperature. The TiO2 aerogels at a temperature higher than 800 degrees C have better stability than anatase because of the formation of partial Ti-O-Si bonds. Copyright (C) 2016 John Wiley & Sons, Ltd.