RUTILE FORMATION IN HYDROTHERMALLY CRYSTALLIZED NANOSIZED TITANIA

Citation
Rr. Bacsa et M. Gratzel, RUTILE FORMATION IN HYDROTHERMALLY CRYSTALLIZED NANOSIZED TITANIA, Journal of the American Ceramic Society, 79(8), 1996, pp. 2185-2188
Citations number
10
Categorie Soggetti
Material Science, Ceramics
ISSN journal
00027820
Volume
79
Issue
8
Year of publication
1996
Pages
2185 - 2188
Database
ISI
SICI code
0002-7820(1996)79:8<2185:RFIHCN>2.0.ZU;2-0
Abstract
The present study shows that peptization aids in the anatase-rutile tr ansformation in hydrothermally processed (250 degrees C, 4000 kPa) tit ania sols produced by the hydrolysis of alkoxide. HREM images show the presence of nanocrystals of 25-55 nm size, The anatase-rutile phase t ransformation in peptized titania is critically dependent on the condi tions of hydrolysis such as the water/alkoxide concentration ratio and the size of the alkoxide. Hydrolysis of the ethoxide gave rise to a p redominantly rutile phase whereas the isopropoxide and butoxide result ed in a predominantly anatase powder, under the same conditions of tre atment, BET surface areas decrease from 107.1 to 68 m(2)/g when the al koxide is changed from tert-butoxide to ethoxide for a given water/alk oxide ratio.