Grain growth and the anatase-to-rutile phase transition in nanostructured titania have been investigated by electron microscopy, X-ray diffraction, and differential thermal analysis. For pure TiO2, thermal treatment resulted in complete phase transition and considerable grain coarsening, because of the grain boundary nucleation mechanism for the rutile phase. The effect of doping of the TiO2 nanophase has also been addressed. Phase transition turned out to be strongly affected by the presence of Ta and Nb because nucleation of rutile was favored at the surface of anatase grains. Doping allowed the maintenance of the ultrafine anatase phase even at high annealing temperature. Thermal analysis highlighted that oxygen mobility in the titania lattice is affected by doping and related to the inhibition of grain coalescence and phase transition.

Effect of dopants on grain coalescence and oxygen mobility in nanostructured titania anatase and rutile

GUIDI, Vincenzo;CAROTTA, Maria Cristina;FERRONI, Matteo;MARTINELLI, Giuliano;SACERDOTI, Michele
2003

Abstract

Grain growth and the anatase-to-rutile phase transition in nanostructured titania have been investigated by electron microscopy, X-ray diffraction, and differential thermal analysis. For pure TiO2, thermal treatment resulted in complete phase transition and considerable grain coarsening, because of the grain boundary nucleation mechanism for the rutile phase. The effect of doping of the TiO2 nanophase has also been addressed. Phase transition turned out to be strongly affected by the presence of Ta and Nb because nucleation of rutile was favored at the surface of anatase grains. Doping allowed the maintenance of the ultrafine anatase phase even at high annealing temperature. Thermal analysis highlighted that oxygen mobility in the titania lattice is affected by doping and related to the inhibition of grain coalescence and phase transition.
Guidi, Vincenzo; Carotta, Maria Cristina; Ferroni, Matteo; Martinelli, Giuliano; Sacerdoti, Michele
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11392/516946
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 69
  • ???jsp.display-item.citation.isi??? 64
social impact