Characterization of ammonium tungsten bronze [(NH4)(0.33)WO3] in the thermal decomposition course of ammonium paratungstate

Authors
Fouad, NE Nohman, AKH Mohamed, MA Zaki, MI
Citation
Ne. Fouad et al., Characterization of ammonium tungsten bronze [(NH4)(0.33)WO3] in the thermal decomposition course of ammonium paratungstate, J AN AP PYR, 56(1), 2000, pp. 23-31
Citations number
12
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
ISSN journal
01652370 → ACNP
Volume
56
Issue
1
Year of publication
2000
Pages
23 - 31
Database
ISI
SICI code
0165-2370(200009)56:1<23:COATB[>2.0.ZU;2-1
Abstract
Ammonium tungsten bronze, (NH4)(0.33)WO3, was characterized in the calcinat ion product of ammonium paratungstate at 400 degrees C for 2 h in a static atmosphere of air. X-ray diffractometry, thermogravimetry, and infrared and UV-vis diffuse reflectance spectroscopies found the yellowish orange produ ct to also contain hexagonal tungsten trioxide, WO3. On heating up to 500 d egrees C, the bronze together with the hexagonal WO3 were transformed compl etely into the yellowish green monoclinic tungsten trioxide. (C) 2000 Elsev ier Science B.V. All. rights reserved.