• Awad Kishore Singh
• Dr. Vipin Kumar

X-ray absorption spectroscopy (XAS) is routinely used to probe the context of transition metal centres in biological systems. Studies involving co-ordination chemistry and X-ray absorption spectroscopy (XAS) are very complementary. Tungsten oxide has had its hydrogen intercalation into its monoclinic (m-WO3), metastable hexagonal (h-WO3), and cubic (c-WO3) phases investigated by in situ x-ray absorption fine structure (XAFS) (at the W L3-edge) and x-ray diffraction (XRD) methods. Using XAFS and XRD data, we were able to reconstitute the local environment surrounding tungsten ions in their initial coordination shell. The outcomes are contrasted with those predicted by currently available structural models. When there is no coordinated water present, the XANES spectra reveals that the surface tungsten oxide species exhibit a distorted tetrahedral structure at coverages of less than 1/3 monolayer. Samples left out in the air at room temperature exhibit octahedral site symmetry due to the coordination of water molecules to the surface tungsten oxide species, however this symmetry breaks down at 500 °C. Raman spectra of the W03/A1203 samples exhibit features attributed to W=O and W-0-W bonds, which is consistent with a deformed tetrahedral tungsten oxide environment. This research suggests that unbound and coupled tetrahedra of tungsten oxide occur on the surface. Tungsten oxide surfaces with coverages near to a monolayer reveal evidence in their XANES spectra of a significant proportion of the surface tungsten oxide sites having a deformed octahedral environment, even in the absence of coordinated water.

XAFS, XRD, tungsten oxides, structure, hydrogen intercalation

"X RAY SPECTROSCOPIC STUDY OF TUNGSTEN COMPOUNDS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.9, Issue 10, page no.41-50, October-2022, Available :http://www.jetir.org/papers/JETIRFU06005.pdf

"X RAY SPECTROSCOPIC STUDY OF TUNGSTEN COMPOUNDS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.9, Issue 10, page no. pp41-50, October-2022, Available at : http://www.jetir.org/papers/JETIRFU06005.pdf