A study about the stabilization of anatase phase at high temperatures on sol-gel cerium and copper doped titania and titania-silica powders

摘要

Copper and cerium oxides doped titania samples, as well as silica-titania samples were prepared through sol-gel process by using titanium butoxyde as precursor. The obtained samples were characterized by X-ray diffractometry and scanning electron microscopy. The main objective of the proposed study is to promote the stabilization of anatase phase at high temperatures. The obtained experimental results show that cerium doped titania samples stabilizes the anatase phase until 800degreesC, whereas copper doped samples calcinated at the same temperature are a mixture of anatase and rutile phases. So, CeO2 is a better stabilizer for anatase phase than CuO. On the other hand, based on previously reported data it can be concluded that both, CeO2 and CuO are better stabilizers for anatase phase than SnO2. It is also verified that the total amount of silica in the titania-silica double oxide increases the temperature required for crystallization, and as a consequence, the anatase phase is stabilized at higher temperatures i.e. lip to 1200degreesC. (C) 2004 Published by Elsevier B.V.