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

This paper successfully synthesized Bismuth oxide (Bi2O3) 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 Bi2O3 NPs was examined through field emission scanning electron microscopy (FESEM) showing spherical nature-like morphology. The gas sensor was fabricated using as-prepared Bi2O3 NPs by standard screen-printing technique and it was tested for various gases such as NH3, NO2, ethanol, LPG, and methanol as a function of operating temperature. The effect of operating temperature and gas concentration were investigated in detail to understand Bi2O3 NPs sensor for NH3 gas and found to be very efficient.