Journal of Materials Science

, Volume 49, Issue 17, pp 5899–5909

WO3 nano-ribbons: their phase transformation from tungstite (WO3·H2O) to tungsten oxide (WO3)

  • Majid Ahmadi
  • Satyaprakash Sahoo
  • Reza Younesi
  • Anand P. S. Gaur
  • Ram S. Katiyar
  • Maxime J-F Guinel
Article

DOI: 10.1007/s10853-014-8304-2

Cite this article as:
Ahmadi, M., Sahoo, S., Younesi, R. et al. J Mater Sci (2014) 49: 5899. doi:10.1007/s10853-014-8304-2

Abstract

Tungsten oxide (WO3) nano-ribbons (NRs) were obtained by annealing tungstite (WO3·H2O) NRs. The latter was synthesized below room temperature using a simple, environmentally benign, and low cost aging treatment of precursors made by adding hydrochloric acid to diluted sodium tungstate solutions (Na2WO4·2H2O). WO3 generates significant interests and is being used in a growing variety of applications. It is therefore important to identify suitable methods of production and better understand its properties. The phase transformation was observed to be initiated between 200 and 300 °C, and the crystallographic structure of the NRs changed from orthorhombic WO3·H2O to monoclinic WO3. It was rigorously studied by annealing a series of samples ex situ in ambient air up to 800 °C and characterizing them afterward. A temperature-dependent Raman spectroscopy study was performed on tungstite NRs between minus 180 and 700 °C. Also, in situ heating experiments in the transmission electron microscope allowed for the direct observation of the phase transformation. Powder X-ray diffraction, electron diffraction, electron energy-loss spectroscopy, and X-ray photoelectron spectroscopy were employed to characterize precisely this transformation.

Supplementary material

10853_2014_8304_MOESM1_ESM.docx (242 kb)
Supplementary material 1 (DOCX 242 kb)
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Supplementary material 2 (TIFF 6795 kb)
10853_2014_8304_MOESM3_ESM.tif (4.5 mb)
Supplementary material 3 (TIFF 4647 kb)

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • Majid Ahmadi
    • 1
  • Satyaprakash Sahoo
    • 1
  • Reza Younesi
    • 2
  • Anand P. S. Gaur
    • 1
  • Ram S. Katiyar
    • 1
  • Maxime J-F Guinel
    • 1
    • 3
  1. 1.Department of Physics, College of Natural SciencesUniversity of Puerto RicoSan JuanUSA
  2. 2.Department of Energy Conversion and StorageTechnical University of DenmarkRoskildeDenmark
  3. 3.Department of Chemistry, College of Natural SciencesUniversity of Puerto RicoSan JuanUSA