In:
Journal of Synchrotron Radiation, International Union of Crystallography (IUCr), Vol. 8, No. 2 ( 2001-03-01), p. 782-784
Kurzfassung:
The structural characterisation of SiO 2 /ZrO 2 nano-sol particles, prepared by mixing SiO 2 sol and aqueous solution of ZrOCl 2 8H 2 O, has been carried out by in-situ XAS measurement at the Zr K-edge during condensation reaction. The detailed XANES features at the Zr K-edge of the mixed sol of SiO 2 /ZrO 2 are compared with those of other references such as ZrO 2 , ZrOCl 2 8H 2 O, BaZrO 3 , and ZrSiO 4 , and it becomes obvious that the Zr 4+ ions are stabilised in an octahedral symmetry. The EXAFS result also indicates that each Zr atom is coordinated with six oxygen ones as the first nearest neighbour, where two oxygen atoms are from the linkage of (Si-O-Zr) at short distance, and four ones are from water molecules at long distance. As the condensation reaction proceeds, it is found that the number of oxygen atoms due to the formation of (Si-O-Zr) bond at short distance and the second neighbour of silicon atoms increase simultaneously. From the above EXAFS and XANES results, the structural and gelating models could be proposed, which is based on the octahedrally coordinated but distorted zirconium species attaching on the SiO 2 sol surface.
Materialart:
Online-Ressource
ISSN:
0909-0495
DOI:
10.1107/S090904950001606X
Sprache:
Unbekannt
Verlag:
International Union of Crystallography (IUCr)
Publikationsdatum:
2001
ZDB Id:
2021413-3
SSG:
13
