Structural Modification of Doped and Undoped Nanocrystalline TiO2 by Temperature-Resolved XRPD
Nanocrystalline titania pigments were produced by a novel synthesis route consisting of a high temperature forced hydrolysis in a coordinating high-boiling solvent. The effect of synthesis conditions as well as doping with Cr, Sb and V on the particle size and on the anatase-to-rutile transformation was studied by temperature-resolved synchrotron powder diffraction. The experiments were performed directly on as-synthesized low concentration suspensions of titania nanoparticles (up to 230°C) and on dried titania nanoparticles (up to 950°C). Crystallite size of as-synthesized nanoparticles is in the 5 to 50 nm range, being affected by the synthesis conditions as well as by doping and exhibits a slow-rate coarsening trend with temperature. The anatase-to-rutile transformation is drastically influenced by both synthesis conditions and doping. In particular, doping affected the anatase-to-rutile transformation rate, while the synthesis conditions influenced the phase composition, causing the appearance of brookite.
P. VINCENZINI and G. MARLETTA
F. Matteucci et al., "Structural Modification of Doped and Undoped Nanocrystalline TiO2 by Temperature-Resolved XRPD ", Advances in Science and Technology, Vol. 51, pp. 99-104, 2006