A simple route to large-scale production of tungsten trioxide nanoparticles

Tungsten trioxide particles in high yield were prepared via a simple solid evaporation route with ammonium paratungstate hydrate as precursor and Ar gas as carrier gas. Detailed characterization by scanning electron microscopy has shown that increasing carrier gas flow rate promotes morphological evolution from large and irregular semi-spherical particles to non-agglomerated quasi-spherical particles, and finally to single-crystalline nanoparticles with an average diameter of 60 nm. The adsorption activity of the tungsten trioxide particles is size-dependent and increased with decreasing particle size. The present method could readily produce large-scale tungsten trioxide nanoparticles with ideal adsorption performance, and can be utilized to fabrication of various semiconductor oxides with advanced properties.