Synthesis of graphene/thorns-like polyaniline/α-Fe₂O₃@SiO₂ nanocomposites for lightweight and highly efficient electromagnetic wave absorber

α-Fe₂O₃@SiO₂ nanoparticles have been successfully enveloped in graphene nanosheets/thorns-like polyaniline matrix (RGO/thorns-like PANI/α-Fe₂O₃@SiO₂ nanocomposites) by some facile strategies. The measured electromagnetic parameters indicate that the interfacial polarization, the charge transfer, the multiple reflections and scatterings, the Debye dipolar relaxation processes, the magnetic loss, the quarter-wavelength matching and the well-matched characteristic impedance all play significant roles in improving the electromagnetic wave absorption performance. The maximum reflection loss of RGO/thorns-like PANI/α-Fe₂O₃@SiO₂ nanocomposites reaches −50.06 dB at 14.4 GHz with a matching thickness of only 2.3 mm, and the absorption bandwidth with reflection loss less than −10 dB is in the 4.0–18.0 GHz range for the absorber thickness of 1.5–5.5 mm. Moreover, the adding quantity of nanocomposites in the paraffin matrix is only 16.7 wt%. Consequently, it is believed that the nanocomposites could be used as an excellent electromagnetic wave absorber with lightweight, thin thickness, broad bandwidth and strong absorption.