Vanadia gel synthesis via peroxovanadate precursors. 2. Characterization of the gels

Citation
Cj. Fontenot et al., Vanadia gel synthesis via peroxovanadate precursors. 2. Characterization of the gels, J PHYS CH B, 105(43), 2001, pp. 10496-10504
Citations number
25
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHYSICAL CHEMISTRY B
ISSN journal
15206106 → ACNP
Volume
105
Issue
43
Year of publication
2001
Pages
10496 - 10504
Database
ISI
SICI code
1520-6106(20011101)105:43<10496:VGSVPP>2.0.ZU;2-B
Abstract
Vanadium oxide gels derived from the reaction of H2O2 and V2O5 have been in vestigated using V-51 MAS NMR, TGA, XRD, SEM, and laser Raman spectroscopy. Based primarily on the V-51 MAS NMR and TGA results, the coordinations of five distinct vanadia sites have been detailed, which possibly include a pr eviously unreported dimer. The relative concentration of these sites change d as dehydration progressed, and a model of this process has been proposed based on the numerical analysis of the NMR MAS spectra. In addition, the co ordination of the most tightly bound water has been postulated. Depending o n sample treatment, it was possible to synthesize both layered and nonlayer ed materials. The laser Raman spectra revealed differences between layered and nonlayered materials. These differences have been attributed to the int eraction of coordinated water molecules, which were trapped between layers and held firmly in place, thus restricting or altering certain Raman-active vibrations.