A novel approach to prepare one-pot Fe/PPy nanocomposite and evaluation of its microwave, magnetic, and optical performance

The aim of this study was preparation of Fe/Fe2O3/Fe3O4 (Fe)/polypyrrole (PPy) nanocomposite using reductive method and investigation of its microwave absorbing properties using polymethylmethacrylate (PMMA) medium. Firstly, PPy was prepared by an oxidative polymerization method with Fe3+ as a doping agent. Next, the Fe/PPy nanocomposite was formed by in situ reduction of Fe2+ and remained Fe3+ with adding sodium borohydride in the solution under an inert nitrogen atmosphere. Finally, PPy and Fe/PPy nanostructures were separately suspended within the PMMA matrix to examine their microwave absorbing characteristics. The prepared PPy and Fe/PPy nanostructures were studied using the Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). The diffuse reflection spectroscopy (DRS) analysis presented a 1.79 eV band gap for the Fe/PPy nanocomposite based on the Kubelka-Munk theory. The vibrating sample magnetometer (VSM) revealed that magnetic properties were reinforced in the Fe/PPy nanocomposite. According to the results obtained by vector network analyzer (VNA), the maximum reflection loss of Fe/PPy/PMMA nanocomposite was −76.02 dB at 8.96 GHz with a thickness of 3.2 mm, absorbing all of the x-band frequency more than 12.72 dB with a thickness of 2.8 mm. Interestingly, the Fe/PPy/PMMA nanocomposite demonstrated a bandwidth >3.4 GHz more than 10 dB from 2.2 to 3.2 mm at the x-band frequency.