Liquefied petroleum gas sensor based on manganese (III) oxide and zinc manganese (III) oxide nanoparticles

In this paper, ${Mn}_2{O}_3$ and ${ZnMn}_2{O}_4$ nanoparticles (NPs) are successfully synthesized using chemical co-precipitation method at room temperature and further annealed at 450 °C. The structure, crystallite size, morphology, specific surface area (SSA) and band gap energy have been determined by x-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller surface area analysis, scanning electron microscopy (SEM-EDS) and UV–visible spectrophotometer. The sensor films of the ${Mn}_2{O}_3$ NPs and ${ZnMn}_2{O}_4$ NPs have been fabricated onto glass substrate using spin coater system separately. These sensor films are investigated for different concentrations (200–1200 ppm) of liquefied petroleum gas (LPG) at different operating temperatures ranging from 100 °C to 400 °C. A comparative study of gas sensing properties shows that spinel ${ZnMn}_2{O}_4$ sensor film exhibit excellent response ($\approx 80\%$) towards 1000 ppm LPG at 300 °C in comparison to ${Mn}_2{O}_3$ sensor films. The enhancement in the gas sensing characteristics of ${ZnMn}_2{O}_4$ sensor film is attributed to the reduced crystallite size, greater SSA, and modification in structure as well as morphology. (paper)