TY - JOUR
T1 - Effects of aging on the kinetics of nanocrystalline anatase crystallite growth
AU - Hsiang, Hsing I.
AU - Lin, Shih Chung
N1 - Funding Information:
The authors would like to express their thanks to the National Science Council of the Republic of China for financial support of this Project (NSC92-2216-E-006-021).
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006/2/10
Y1 - 2006/2/10
N2 - In this study, the effects of aging on crystalline phases, crystallite sizes and agglomeration of TiO2 gels were investigated using thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffraction (XRD), BET specific surface area analyzer and transmission electron microscopy (TEM). The activation energies of anatase crystallite growth for aged and unaged gels were calculated to determine and explain the growth mechanism. TiO 2 aging treatment decreased the number for hydroxyl ions existing in the anatase, resulting in lowering the rate of surface area reduction and decreasing the amount of agglomeration after calcination. The activation energy values for crystallite growth in samples with aging treatment were greater than that found in unaged samples. In nanocrystalline anatase samples without aging treatment, the oriented attachment controlled the crystallite growth. However, grain boundary diffusion controlled the crystallite growth for nanocrystalline anatase samples with aging treatment.
AB - In this study, the effects of aging on crystalline phases, crystallite sizes and agglomeration of TiO2 gels were investigated using thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffraction (XRD), BET specific surface area analyzer and transmission electron microscopy (TEM). The activation energies of anatase crystallite growth for aged and unaged gels were calculated to determine and explain the growth mechanism. TiO 2 aging treatment decreased the number for hydroxyl ions existing in the anatase, resulting in lowering the rate of surface area reduction and decreasing the amount of agglomeration after calcination. The activation energy values for crystallite growth in samples with aging treatment were greater than that found in unaged samples. In nanocrystalline anatase samples without aging treatment, the oriented attachment controlled the crystallite growth. However, grain boundary diffusion controlled the crystallite growth for nanocrystalline anatase samples with aging treatment.
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U2 - 10.1016/j.matchemphys.2005.06.019
DO - 10.1016/j.matchemphys.2005.06.019
M3 - Article
AN - SCOPUS:27644570207
SN - 0254-0584
VL - 95
SP - 275
EP - 279
JO - Materials Chemistry and Physics
JF - Materials Chemistry and Physics
IS - 2-3
ER -