Ammonia Gas Sensing Properties of Bismuth Oxide Thick Films and Its Structural, Optical, Morphological Characterization

This paper successfully synthesized Bismuth oxide (Bi 2 O 3 ) nanoparticles (NPs) using the sol–gel method as Bismuth nitrate pentahydrate as a precursor. The average crystallite size of the NPs was characterized by X-ray diffraction (XRD) analysis and the size of the NPs found to be 17 nm. For the band gap measurement UV-visible spectra of NPs were recorded and it was found to be 2.7 eV. The surface morphology of Bi 2 O 3 NPs was examined through field emission scanning electron microscopy (FESEM) showing spherical nature-like morphology. The gas sensor was fabricated using as-prepared Bi 2 O 3 NPs by standard screen-printing technique and it was tested for various gases such as NH 3 , NO 2 , ethanol, LPG, and methanol as a function of operating temperature. The effect of operating temperature and gas concentration were investigated in detail to understand Bi 2 O 3 NPs sensor for NH 3 gas and found to be very efficient.