Large scale hydrothermal synthesis of monodisperse hexagonal WO3 nanowire and the growth mechanism

Monodisperse hexagonal tungsten oxide (h-WO3) nanowires were novelly prepared on a large scale by the hydrothermal method with the assistance of K2SO4 and Na2SO4. The morphologies and structures of the nanowires were characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM) and high-resolution transmission electron microscopy (TEM). These nanowires with a diameter of 80 nm and high crystallinity are especially bundles-like structure, which are growth from primary particles with same growth direction of [001] and the exposure to 〈200〉 facets. These primary nanoparticles are believed to have a crystal structure of hexagonal prism morphology. Based on the TEM characterizations and crystal structure analyses, the morphology evolvement and is given and the growth mechanism is discussed. This research is potentially applied to controlled synthesis 1D semiconductor oxides through hydrothermal route.