Synthesis and characterization of WO{sub 3} spherical nanoparticles and nanorods

Graphical abstract: Two different morphology WO{sub 3} nanoparticles are synthesized by a simple and new wet chemical route through control over pH, temperature and structure directing agents. Reaction mechanism has been proposed for the formation of different morphologies. Nanorod WO{sub 3} has better crystallinity with less specific surface area compared to the spherical nanoparticles. Comparable band gaps are obtained for both the nanoparticles. - Highlights: • Spherical WO{sub 3} nanoparticle and nanorod synthesis mechanisms proposed. • Thermal analysis and spectroscopy confirms the intermediate reactions. • Both of the morphology has pure and monoclinic phase with identical band gap energy. - Abstract: Simple and new wet chemical routes are adopted for the synthesis of tungsten trioxide (WO{sub 3}) nanopowders having two different morphologies such as spherical and rod-like. Acid catalyzed exothermic reaction and a structure directing reagent have been used to control the formation of spherical and rod shaped nanoparticles, respectively. Thermal analysis and FTIR spectral data have been used to confirm the formation of the intermediate and the ultimate reaction products. X-ray and Raman spectroscopic data indicate the monoclinic structure of both forms of the particles. Rod shaped WO{sub 3} particles exhibit better crystallinity and low specific surface area compared to those exhibited by spherical particles. Band gaps are found to be nearly identical irrespective of the morphology.