Efficient electromagnetic wave absorption performances dominated by exchanged resonance of lightweight PC/Fe3O4@PDA hybrid nanocomposite

For the past few years, the practical microwave absorbing materials with the features of being lightweight, efficient and adaptable to the environment have raised considerable concern. In this work, a lightweight porous carbon/Fe3O4@polydopamine (PC/Fe3O4@PDA) hybrid nanocomposite comprised of flour derived porous carbon, adhered magnetic Fe3O4 nanospheres and conductive polymer coating was successfully prepared through a carbonization, hydrothermal and self-polymerization process. By virtue of the synergistic effect of various components with different loss mechanisms and generated heterogeneous interface, the electromagnetic wave (EMW) attenuation capability of the product was greatly enhanced with the minimum reflection loss (RLmin) of −46.67 dB at a matching thickness of 2.44 mm. Meanwhile, its optimal effective absorbing band (EAB) reached 6.96 GHz at a thickness of 2.17 mm. More attention should be paid to an intriguing phenomenon that exchanged resonance was dominant compared with other factors in determining the absorption performances of the hybrid nanocomposite, which was not reported in previous work. These excellent absorption performances coupled with the lightweight property endowed the PC/Fe3O4@PDA hybrid nanocomposite with a promising application as a novel microwave absorbing material.