Spectroscopic and microscopic study of vanadium oxide nanotubes

V(2)O(5) nanotubes synthesized via the sol-gel route has been studied by electron energy loss spectroscopy (EELS), x-ray absorption spectroscopy (XAS), and energy dispersive x-ray analysis, in order to understand the local structure of vanadium in the nanotubes. Contrary to our expectation, all the features of the XAS and EELS spectra of the V(2)O(5) nanotubes are in line with that of bulk layered vanadium oxide revealing that vanadium is present in the 5(+) oxidation state in the nanotubes. However, V(2)O(5) nanotubes exhibit additional surface states in their electronic structure in comparison with bulk V(2)O(5). A comparison of measured and calculated spectra allows us to distinguish single-wall from multiwall V(2)O(5) nanotubes. (c) 2007 American Institute of Physics.