Effect of Silicon Dioxide on the Formation of the Phase Composition and Pore Structure of Titanium Dioxide with the Anatase Structure

摘要

The formation of the structure of titanium dioxide modified with silicon dioxide, which was introduced as tetraethyl orthosilicate, was studied. It was found that the formation of the nanocrystalline structure of TiO2 occurred upon the modification of titanium dioxide with silicon dioxide. This nanocrystalline structure of TiO2 was formed by highly dispersed anatase particles of size 6-10 nm stabilized by silicon oxide layers, which were formed upon the decomposition of tetraethyl orthosilicate. An increase in the modifier concentration resulted in a deceleration of the growth of anatase particles and an increase in the temperature of the phase transition of anatase to rutile. It was found that the anatase phase in the samples containing 5-15 wt % SiO2 was stable up to 1000 degrees C. The stabilization of highly dispersed anatase particles facilitated the retention of the developed fine-pore structure of xerogels with a pore diameter of 4 nm up to 900 degrees C.