Structural and thermal properties of in-situ reduced WO3 to W powder

Tungsten nanoparticles have been synthesized by the chemical reaction route. Reduction of WO3 with the in situ produced hydrogen gas at 600 °C in current work is a new approach for the production of W nano-powder. The results of XRD show that nanostructure α-W and β-W is present in the final product. Differential thermal analysis (DTA) showed the β → α phase transition occurs around ~ 435 °C. The morphology and particle size distribution of tungsten nanosized powders have been analyzed by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that an average crystallite size of product W nanopowder is about 32 nm.

This study presents a new method to produce tungsten nanosized powder with a spherical morphology by in situ produced hydrogen gas in an autoclave at 600 °C. Purity of synthesized tungsten nanopowder increases with increasing the reaction time from 15 h to 20 h. SEM image shows that produced nanopowders are of very fine size having high surface area as these get agglomerated easily.Figure optionsDownload as PowerPoint slideHighlights
► W nanopowder was synthesized by a chemical reaction method.
► The synthesis time greatly affects the nanopowder production.
► In situ produced hydrogen gas enhanced the reaction mechanism.