Berlin 2005 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 30: POSTER: Chemical physics

CPP 30.33: Poster

Dienstag, 8. März 2005, 16:30–18:30, Poster TU D

A TEM and XANES study of vanadium oxide nanotubes — •A. Gloskovskii¹, S. A. Nepijko¹, G. Schönhense¹, A. Reiber², H. A. Therese², G. H. Fecher², H. C. Kandpal², C. Felser², W. Tremel², and M. Klimiankou³ — ¹Institut für Physik, Johannes Gutenberg - Universität, 55099 Mainz — ²Institut für Anorganische und Analytische Chemie, Johannes Gutenberg - Universität, 55099 Mainz — ³Institut für Materialforschung I, Forschungszentrum Karlsruhe GmbH, 76021 Karlsruhe

The vanadium oxide nanotubes used in this study were synthesized using the sol-gel technique following the procedure reported by Krumeich et al. [1]. TEM studies of vanadium oxide nanotubes show that the samples consist of multi-walled nanotubes with inner diameters in the range of 20-40 nm, and a length of typically several µ m (it can even reach tens of µ m). Spectroscopic measurements were performed to understand the electronic state of vanadium in relation to bulk material. The EDX and EELS measurements revealed that the chemical formula of the nanotubes is V₂O₅. Comparison of XAS measurements taken from nanotubes and bulk V₂O₅ revealed an overall similarity but also significant differences in details between their spectra. The latter can be explained by a major contribution of the surface to the electronic structure and electronic transitions of V₂O₅ nanotubes in comparison to bulk material. Band structures for both bulk and slab V₂O₅ were calculated by LMTO and FLAPW methods showing a good agreement with the experiment.

(This work is funded by the DFG in SFB 625 TP9.)

[1] F. Krumeich et al.; J. Am. Chem. Soc. 121, (1999) 8324