A highly sensitive gas sensor based on Pd-doped Fe3O4 nanoparticles 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 degrees 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.