A Bi 2 O3 nanomaterial was fabricated by a facile and low temperature solid state method using a basic bismuth nitrate raw compound at 400 ˚C and 14 h. Rietveld analysis data indicated that α-Bi 2 O3 was crystallized well in monoclinic crystal system with the space group of P121 /c1. The morphology of the synthesized material was studied by field emission scanning electron microscope (FESEM). The direct band gap energy (Eg) value was calculated by ultraviolet – visible (UV-Vis) spectroscopy. The peaks at 400 – 550 cm-1 are assigned to oxygen – metal – oxygen (O-M-O) vibrations. The data showed that the Eg of the synthesized material was about 2.2 eV. In addition, the vibrating-sample magnetometer (VSM) analysis data confirmed that the synthesized sample had ferromagnetic behavior. Further, gas sensing property of the synthesized Bi 2 O3 nanomaterial for carbon monoxide gas was studied, and the data confirmed the good sensitivity of the prepared sensor at low CO concentrations.
