An electrospinning deposited cobalt oxide nanofiber gas sensing device: selective enhancement as a thermal electronic nose

Cobalt oxide nanofibers (Co₃O₄ NFs) were synthesized using a two-step procedure involving electrospinning followed by calcination. The microstructural, morphological, and elemental properties of the nanofibers were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive spectrometry (EDS). The Co₃O₄ NFs exhibited high structural integrity, chemical purity, and uniform diameters ranging from 20 to 50 nm. Thermal treatment at 600 °C for 3 hours transformed the electrospun fibers into elongated nanofibers composed of interconnected Co₃O₄ nanoparticles. The gas sensing properties of the Co₃O₄ NFs were evaluated for ethanol (C₂H₅OH) detection over a temperature range of 250 to 450 °C. The sensor demonstrated a significant response to ethanol, highlighting their potential for gas sensing applications. When employed as a thermal electronic nose, the device achieved perfect classification (100% accuracy) for six tested gases and demonstrated effective concentration estimation, with an average error of 28.6%.