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.