Effect of Brookite presence on nanocrystalline anatase-rutile phase transformation

TiO2 nanocrystals were prepared by hydrolysis and peptization of titanium isopropoxide under different pH values. The as-prepared powder was consisting of very fine anatase crystallites ranges from 7.9 nm in acidic solution of pH 3, to 10.2 nm in basic solution of pH 8. Further heat-treatments revealed the anatase – rutile transformation depends not only on primary crystallite size, but also some other factors, such as agglomeration and presence of brookite phase are also involved. It was concluded that, among powders with the same size the presence of agglomeration and brookite phase would accelerate the anatase- rutile transformation.

Keywords:

hydrolysis , peptization , anatase , rutile , transformation , TiO2 nanocrystals