Abstract: The rational construction of lightweight composites with multiple heterogeneous interfaces represents an effective strategy for achieving efficient electromagnetic wave (EMW) absorption. However, the impact of multiple heterogeneous interfaces on electromagnetic performance still needs further exploration. Herein, reduced graphene oxide (rGO)@Ni-FeCo layered hydroxide (LDH) derivatives with multiple heterostructures were synthesized by a series of processes including electrostatic self-assembly, freeze-drying and thermal annealing. The conductive network in rGO and the cavities inside LDH facilitate electron migration and effectively prolong the propagation path of EMW, thereby enhancing conductivity loss. The abundant heterogeneous interfaces between carbon components and metal nanoparticles induce interfacial polarization. In addition, the catalytic activity differences of different metal particles generate different dielectric electromagnetic interfaces, which further promote interfacial polarization. The natural and exchange resonance formed by magnetic particles under a magnetic field provides magnetic losses. Therefore, the successful construction of multiple heterogeneous interfaces effectively enhances the conductivity loss and polarization loss. With a thickness of only 1.4 mm, the composite achieves a minimum reflection loss of -51.8 dB and an effective absorption bandwidth of 4.5 GHz. This work provides an effective strategy for achieving thin thickness and efficient EMW absorption through precise structural design and multi-component construction of absorbers.

Key words: Electromagnetic wave absorption, Multiple heterogeneous interfaces, Conductivity loss, Polarization loss