Abstract: The atomic-scale design of multicomponent synergistic systems remains a critical bottleneck to developing high-performance lightweight electromagnetic wave (EMW) absorbers. Herein, we propose a microwave reduction strategy to fabricate Fe clusters/reduced graphene oxide composites with co-assembled single-atom and sub-nanocluster configurations. By simple Fe concentration control, an optimal spatial distribution is achieved, enabling synergistic localized-delocalized mechanisms. The single-atom induce intense localized polarization through its unsaturated coordination, while the adjacent sub-nanoclusters establish delocalized electron networks for enhanced conduction loss. Owing to synergy, the optimal composite exhibits exceptional EMW absorption performance, achieving a minimum reflection loss of -62.26 dB and an effective absorption bandwidth of 6.32 GHz at an ultralow filler loading of 1.0 wt.%. The superior performance originates from an atomic-cooperative effect between localized polarization and delocalized conduction pathways, which is directly verified by first-principles calculations that reveal a pronounced increase in the density of states and the significant interfacial charge redistribution. This performance advantage over most reported low-filler systems highlights the merit of atomic-scale cooperative design for lightweight, highly efficient EMW absorption and paves the way for next-generation absorbers via the rational design of atomic-scale cooperative units in low-dimensional systems.

Key words: Electromagnetic wave absorption, Microwave reduction, Fe-doped graphene, Electronic structure modulation, Synergistic effect