The green synthesis rGO/Fe3O4/PANI nanocomposites for enhanced electromagnetic waves absorption

•The rGO/Fe3O4/PANI nanomaterial with unique structure has been successfully prepared.•This rGO/Fe3O4/PANI with multi-interface is efficient for EM wave absorption.•The better impedance matching leads to efficient EM wave absorption. In this work, a simple, green, and large-scale synthesis method was designed to prepare rGO/Fe3O4/PANI nanocomposites without harmful reducing agent. Reducible aniline was used to reduce the graphite oxide which has loaded Fe3O4 nanoparticles, and resulting aniline nitrenium cation on the surface of rGO and supplementary aniline monomer can further take place the oxidation polymerization initiated by ammonium persulfate. The ternary rGO/Fe3O4/PANI nanocomposite with multi-interface thus constructed is expected to be benefit for impedance matching, which results in good magnetic permeability and dielectric properties for wave absorbing. The morphology and chemical structures of the resulting ternary nanocomposites were characterized by TEM, FTIR, TGA and UV–vis, respectively. The rGO/Fe3O4/PANI composite with multi-interface shows excellent wave-absorbing property with the maximum reflection loss of -51.5 dB with thickness of 2 mm and the absorption bandwidth with below -10 dB is 4.2 GHz. The excellent wave-absorbing property is caused by the unique structural characteristics with multi-interface and the better impedance matching between electrical loss and magnetic loss.