Effect of Thermal Treatment on Morphology and Acetone Gas Sensing Properties of Fe₃O₄-C Nanocomposites Prepared via Green Synthesis

Abstract

Fe3O4-C nanostructured composites were used for the fabrication of thin films as active layers in resistive chemical sensors. Nearly spherical and like-sheet porous structures were obtained via green method using olive leaf extract (OLE) followed by thermal process at 300°C and 550°C, respectively, for high-performance gas sensing applications. The prepared sensors were measured with various concentrations of toxic gases such as acetone (C3H6O), ethanol (C2H5OH), and carbon dioxide (CO2) at different operating temperatures. The gas sensing results illustrated that the porous structure of Fe3O4-C nanocomposite exhibited high response of 15.71, 225.35 and 3141.66 toward 20, 100 and 1000 ppm of acetone gas at 300°C. The sensor based on porous structure of Fe3O4-C nanocomposite also indicated fast response and recovery time as well as higher response to acetone compared to ethanol and CO2 gases. The better gas-sensing properties of the porous nanostructures can be attributed to the higher surface area of porous compared with the nearly spherical structure which is confirmed using BET analysis. The gas sensing performance of porous Fe3O4-C nanocomposite reveals that it can be a good sensing material for the fabrication of acetone gas sensors.