A highly sensitive gas sensor based on Pd-doped Fe₃O₄nanoparticles for volatile organic compounds detection

Novel sensing materials, Pd-supported Fe3O4 nanoparticles (Pd@Fe3O4), were successfully prepared and characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) in this study. The gas sensing properties of the Pd@Fe3O4 nanoparticles were systematically investigated. The results showed that the doped Pd could significantly enhance the gas sensing characteristics of Fe3O4. The Pd@Fe3O4 nanoparticles present high sensitivity to diverse volatile organic compounds (VOCs), such as methanol, ethanol, propanol, acetone, etc. The response and recovery time towards 40 ppm of ethanol at 300 °C were 18 s and 30 s, respectively. The enhanced sensor performance was attributed to the catalytic properties of Pd nanoparticles, and a possible mechanism was proposed.