Mahshad Alaei - Department of Chemistry, Faculty of SciencesTarbiat Modares University (TMU)
Alireza Mahjoub - Department of Chemistry, Faculty of SciencesTarbiat Modares University (TMU)
Alimorad Rashidi - Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI)

Two different morphologies of WO3 nanostructures were prepared by two different methods and their photo catalytic property was compared in the Congo Red photo degradation. Tungsten trioxide nanoparticles with monoclinic structure and average particle size about 80 nm were prepared by the spray pyrolysis method.WO3 nanorods with hexagonal structure and average dimension about 15 × 100 nm were synthesized in gram quantities by modified hydrothermal method at lower temperature and shorter reaction time in comparison to the previous research. Photo degradation of Congo Red showed that the as-prepared WO3 nanoparticles is more effective than nanorod structure. WO3 nanorods actually had no effect in Congo Red photo degradation. Therefore in this reaction, spherical morphology is superior to column morphology.The samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), EDX analysis UV-visible spectrum and transmission electron microscopy (TEM).

WO3 Nanoparticles;WO3 Nanorod;hydrothermal method; photo catalyst