The Novel Polarization Behaviors Induced by the Synergy of Fe Single Atoms and Multiscale Pores for High‐Performance Absorbers

Abstract 2D electromagnetic wave absorption (EMA) materials have been regarded as promising candidates to address the hazards of excess electromagnetic wave (EMW) exposure. However, the inherent high conductivity and limited polarization behaviors make them cannot satisfy broad frequency absorption requirements. Herein, a novel system is designed where Fe nanoparticles (NPs) and single atoms (SAs) are co‐modified on the nitrogen‐doped carbon nanosheets (NC) with controllable pore defects to achieve broad frequency absorption. In such a system, the introduction of multiscale pores can effectively optimize the impedance matching and thus allow more EMW to enter 2D materials. Furthermore, the synergy of Fe SAs and pores can induce abundant polarization behaviors, forming novel large dipole like Fe NPs/SAs, SAs/pore, and NPs/pore, which contributes to the strong EMW absorption at medium‐high frequency. Consequently, the as‐prepared Fe/NC composites exhibit an ultrabroad effective absorption bandwidth of 10.1 GHz at 2.1 mm and a remarkable absorption intensity of −119.1 dB, which is among the highest values ever reported for EMA materials. This work paves new paths for the design of ultrathin 2D absorber systems with strong wideband absorption performance and offers insights into the effect of pore defects modulation on dielectric features.