Structure, Optical and Formaldehyde Sensing Properties of Co-Precipitated Fe-Doped WO3 Nanomaterials

Co-precipitated undoped and Fe-doped WO3 nanomaterials have been investigated by X-ray diffraction, Raman spectroscopy and scanning electron microscopy in order to study the influence of Fe doping in their structural and morphological properties. The synthesized WO3 nanomaterials have been found to possess monoclinic structure having average crystallite sizes 15-20 nm. The diffuse reflectance spectroscopy shows the optical bandgap similar to 2.85 eV. The 1.8 at.% Fe-doped WO3 exhibits selective high response to formaldehyde over methanol, ethanol, propan-2-ol and acetone. It exhibits the maximum response (similar to 80%) to formaldehyde at the operating temperature of 225 degrees C for 50 ppm concentration in air.