Methods of producing tungsten nanoparticles

A method of producing tungsten-containing nanoparticles, comprising providing a tungsten alkoxide;

• providing a microemulsion comprising two immiscible liquids, one aqueous liquid and one non-aqueous liquid, and a surfactant;
• mixing the tungsten alkoxide with the microemulsion at room temperature;
• allowing the tungsten alkoxide to be hydrolyzed to form tungsten-containing nanoparticles at room temperature;
• removing the surfactant by washing;
• and reducing the tungsten-containing nanoparticles to form metallic tungsten nanoparticles, wherein the microemulsion contains a sufficient amount of a water-containing component to hydrolyze the tungsten alkoxide and the tungsten-containing nanoparticles have an average particle size of less than about 5 nanometers, and wherein reducing comprises heating the tungsten-containing nanoparticles to about 500° C. in the presence of at least about 1% by volume hydrogen.