Solid-State Synthesis of Hexagonal Tungsten Trioxide Nanorods

Hexagonal tungsten trioxide nanomaterials were synthesized from ammonium metatungstate using a solid-state method. The reaction temperature had a significant effect on the morphology, crystal phase and optical absorption properties of the tungsten trioxide nanomaterials. Increasing reaction temperature promoted the morphological evolution from hollow spheres to nanobelts. Hexagonal phase nanorods of width 300–600nm and length 10–30µm were obtained at a reaction temperature of 900°C, and possessed the narrowest band gap among the obtained samples. This method is applicable for the large scale production of hexagonal tungsten trioxide particles with favorable optical absorption properties. It can also be used to fabricate various semiconductor oxides with advanced properties.