Novel route to WOx nanorods and WS2 nanotubes from WS2 inorganic fullerenes

WOx (2 < x < 3) and WS2 nanostructures have been widely praised due to applications as catalysts, solid lubricants, field emitters, and optical components. Many methods have been developed to fabricate these nanomaterials; however, most attention was focused on the same dimensional transformation from WOx nanoparticles or nanorods to WS2 nanoparticles or nanotubes. In a solid-vapor reaction, by simply controlling the quantity of water vapor and reaction temperature, we have realized the transformation from quasi-zero-dimensional WS2 nanoparticles to one-dimensional W18O49 nanorods, and subsequent sulfuration reactions have further converted these W18O49 nanorods into WS2 nanotubes. The reaction temperature, quantity of water vapor, and pretreatment of the WS2 nanoparticle precursors are important process parameters for long, thin, and homogeneous W18O49 nanorods growth. The morphologies, crystal structures, and circling transformation mechanisms of sulfide-oxide-sulfide are discussed, and the photoluminescence properties of the resulting nanorods are investigated using a Xe lamp under an excitation of 270 nm.