Magnetic, optical and carbon monoxide gas sensing properties of a facile solid state fabricated Bi2O3 nanomaterial

A Bi2O3 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-Bi2O3 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 Bi2O3 nanomaterial for carbon monoxide gas was studied, and the data confirmed the good sensitivity of the prepared sensor at low CO concentrations.