Abstract :

This paper presents synthesis and characterization of tungsten oxide (WO3) nanoparticles using EDTA as surfactant by simple household microwave irradiation (2.45 GHz) method. The samples were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–visible diffusion reflectance spectroscopy (UV–VIS-DRS). Powder XRD results revealed that both samples prepared with and without surfactant crystallize in the orthorhombic structure corresponding to WO3•H2O phase. Subsequent annealing under identical conditions (600◦C/air/6 h) led to significantly different products i.e. monoclinic W17O47 from surfactant free sample and similarly monoclinic phase of WO2.72 from EDTA assisted sample. Blue emission was observed through UV–VIS-DRS with band gap energy around 3.28 and 3.47 eV for EDTA assisted samples respectively.