Synthesis of large-surface area silica modified titanium (IV) oxide ultrafine particles

Abstract

Thermal reaction of titanium (IV) tetra -tert -butoxicle in organicmedia (1,4 butanediol, toluene, 2propanol) at 300 (+,ฐ)C under autogenouspressure yielded nanocrystalline anatase titanium (IV) oxides with diameterof 16-42 nm and BET surface area of 42-100 m2 g I. The physical propertiesand thermal stability of assynthesized titanium (IV) oxide can becontrolled by the reaction of crystallite formation which depended on thetype of organic solvent besides reaction conditions and structure of thealkyl group of the metal alkoxides. When the reaction of crystalliteformation occurs rapidly and so does the crystallization of products thenassynthesized titanium (IV) oxide obtained is well-crystallized anatasehaving high thermal stability. Thermal stability of titanium (IV) oxide canbe improved by the addition of tetraethyl orthosilicate (TEOS) in reactionmixture yields silica modified titanium (IV) oxide, which has highersurface area and thermal stability. However, the increase of TEOS contenttends to yield amorphous phase instead of anatase structure.