Dual-resonant cavities-induced hierarchical heterogeneous enhancement effect of multi-interfacial microspheres for broadband microwave absorption

Recently, the multi-components hybridization technology and heterogeneous interface design have became the effective pathway to enhance microwave absorption (MA) performance and broaden the effective absorption bandwidth (EAB). To illustrate the heterointerface polarization in the multiscale, this work introduced multi-axis co-electrospinning technology to design a type of multi-components graphene-based aerogel microspheres (GAMs) with two resonant cavities that owing multiple heterogeneous interfaces. The artificial interfaces, engineered at submillimeter scales, were constructed based on triple tangent sphere-like absorbers with differentiated electromagnetic characteristics, possessing both outstanding impedance and attenuation ability. The typical H@ZnO/C/Fe 3 O 4 GAMs-3 displayed impressive reflection loss ( RL min ) of −61.5 dB at 9.58 GHz, and simultaneously the corresponding EAB reached 6.63 GHz. Besides, the widest EAB of this composite was 8.5 GHz, remaining that the RL min values reached −36.92 dB. It revealed that synergistic interface effect in the macro-micro-nano scale could extremely improve scattering properties in the multi-shell cavity. On this basis, the group effect of layered stacked model for different types of GAMs models was explored via electromagnetic simulation, demonstrating that the macro-scale interface between different microsphere individuals could induce electromagnetic polarization. This research emphasized the significance of multi-scale heterointerface engineering in optimizing MA performance, offering new pathways for broadband MA materials.