In-situ growth of Co3O4 nanoparticles based on electrospray for an acetone gas sensor

In this study, Co3O4 nanoparticles were prepared using the electrospray method and were then deposited in-situ on a substrate to fabricate an acetone gas sensor. The physicochemical properties of the samples were investigated using scanning electron spectroscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The growth of the Co3O4 nanoparticles was confirmed by SEM. The Co3O4 nanoparticles showed the spinel structure, as revealed by the XRD results. The chemical composition of the prepared material and the chemical states of Co and O were investigated using XPS. The gas sensing properties of the electrosprayed Co3O4 nanoparticles were analyzed. The nanomaterials exhibited excellent acetone sensitivity. At the optimum working temperature of 200 °C, the response to 100 ppm acetone was 8.61, and the response and recovery times were 43 and 92 s, respectively. Moreover, sub-ppm acetone could be detected by the sensor. The Co3O4 nanoparticle-based sensor showed excellent sensitivity to acetone in the presence of methanol, ethanol, isopropanol, benzene, and ethyl acetate. The sensor showed a relative standard deviation of response of approximately 3.893%–100 ppm acetone over 10 days in the atmospheric environment. The acetone-sensing mechanism of the electrosprayed Co3O4 film was also investigated.