Open AccessThe synthesis of tungsten trioxide gel by dissolution of tungsten in hydrogen peroxide and its transformations during the heat treatment in oxidation and reduction atmospheres
Author(s) -
Radovan Georgijević,
Slavko Mentus
Publication year - 2011
Publication title -
hemijska industrija
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.147
H-Index - 19
eISSN - 2217-7426
pISSN - 0367-598X
DOI - 10.2298/hemind101228009g
Subject(s) - tungsten trioxide , dissolution , scanning electron microscope , tungsten , hydrogen peroxide , thermogravimetric analysis , materials science , amorphous solid , particle size , monoclinic crystal system , evaporation , analytical chemistry (journal) , thermal analysis , chemistry , nuclear chemistry , inorganic chemistry , metallurgy , thermal , crystallography , chromatography , organic chemistry , physics , meteorology , crystal structure , composite material , thermodynamics
The structure and the thermal behavior of WO3 samples in air and in reduction atmosphere were studied. The sample I was prepared by the dissolution of fine metallic tungsten powder in hydrogen peroxide followed by solvent evaporation in the air at 60°C. Sample II was obtained by draining a part of the sample I at 60°C and then heating it up to 430°C. By the means of X-ray diffractometry, scanning electron microscopy and thermal analysis it was evidenced that the sample I was the amorphous hydrated gel, with the WO3•1.5H2O composition, while the second one was the anhidrous monoclinic WO3 with the mean particle size of 100 nm. Additionally, using the thermogravimetric and the differential thermal analysis simultaneously in the reduction atmosphere, both samples types were examined. After reduction the distribution of the metal particles number in respect to the diameters of the anhidrous sample was examined using the electron microscopy