Heterointerface engineering of N-doped graphene aerogels anchored with ultra-small Co and MnO nanoparticles for excellent electromagnetic wave absorption

Ultra-thin and lightweight excellent electromagnetic wave (EMW) absorption materials have seen increased attention due to their potential to address electromagnetic pollution. Combining heterointerface engineering and an intrinsic interfacial polarization response has resulted in material development that has demonstrated improved EMW absorption capabilities, yet the underlying mechanisms are not well understood. Herein, we construct a three-dimensional (3D) N-doped reduced graphene oxide aerogel containing abundant heterointerfaces between ultrasmall Co and MnO nanoparticles (NrGO/Co–MnO aerogels), with Co and MnO particle diameters of ∼6.0 nm. These 3D NrGO/Co–MnO aerogels produce a reflection loss of −51.7 dB and an effective absorption bandwidth of 4.08 GHz, much higher than that of the single-phase aerogels. The density functional theory calculations and experimental results indicate that the strong interfacial polarization caused by the charge redistribution at Co/MnO heterointerfaces, defect-induced polarization, and the synergistic effect between dielectric and magnetic loss enhance the electromagnetic wave absorption property of the 3D aerogels. These findings provide important insights and a basis for creating effective EMW materials and highlight the promise of heterointerface engineering in nanomaterials.