title: Rationale for the crystallization of titania polymorphs in solution.
abstract: We use in situ X-ray absorption and diffraction studies to directly monitor the crystallization of different titania polymorphs in one and the same solution. We find that, despite the commonly accepted polymorphic-crossover from anatase to rutile triggered by the critical size of nanoparticles, in the solution their respective nucleation and growth are independent processes. Moreover, we find that 5.9 nm rutile nanoparticles are formed prior to the formation of 8.4 nm anatase nanoparticles. Our results suggest that the origins of this crystallization mechanism lie in the formation of an intermediate non-crystalline phase and in time-dependent changes in the chemical environment.
authors.affiliation: Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland. dorota.koziej@mat.ethz.ch.
authors.forename: N
authors.initials: N
authors.lastname: Kränzlin
authors.forename: M
authors.initials: M
authors.lastname: Staniuk
authors.forename: F J
authors.initials: FJ
authors.lastname: Heiligtag
authors.forename: L
authors.initials: L
authors.lastname: Luo
authors.forename: H
authors.initials: H
authors.lastname: Emerich
authors.forename: W
authors.initials: W
authors.lastname: van Beek
authors.forename: M
authors.initials: M
authors.lastname: Niederberger
authors.forename: D
authors.initials: D
authors.lastname: Koziej