Preparation of La2O3 doped ultra-fine W powders by hydrothermal-hydrogen reduction process

In the present study, hydrothermal-hydrogen reduction process as a novel wet-chemical route was performed for the preparation of La2O3 doped ultra-fine W powders. WO3 precursor powders with nanorods were fabricated by the hydrothermal reaction of sodium tungstate, citric acid and sodium sulfate in aqueous solutions in autoclave, and then were reduced by high purity hydrogen to obtain doped tungsten powders. Reaction time and PH value of solution affected morphology of WO3 precursor powders and following doped tungsten powders. TEM results revealed that the obtained La2O3 doped W powders presented good sphericity with particle size of about 700 nm and narrow particle size distribution, which was determined mainly by the diameter of rod-like WO3 due to in-situ hydrogen reduction mechanism.

Graphical abstractLa2O3 doped ultra-fine W powders were prepared by hydrothermal-hydrogen reduction process for the first time. Notably particularly, the as-synthesized precursor is WO3 nanorods and the as-reduced powders by this process possess narrow particle size distribution and good sphericity, compared to other wet-chemical methods. Besides, TEM and SAED analysis indicated La2O3 phase was doped in the tungsten crystal.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► La2O3 doped W powders were prepared by hydrothermal-hydrogen reduction process. ► The precursor is hexagonal WO3 nanorods. ► The reduced powder possess narrow particle size distribution. ► The grain size of reduced powders is determined by the diameter of WO3 nanorods. ► La2O3 phase can be detected in tungsten crystal.