LAUSR

Abstract The design of magnetic/dielectric composites with rational nanostructures can greatly determine the electromagnetic wave absorption performance of absorbers. Herein, the porous magnetic Co nanospheres supported on lightweight dielectric nitrogen-doped graphene (N-GN) were prepared through a simple one-pot solvothermal method as enhanced synergistic electromagnetic wave absorbers. The Co nanocrystals show porous spherical shape with hexagonal phase, which are supported uniformly on the crumpled N-GN without conglomeration. Even powerful ultrasound treatment cannot separate the Co nanospheres from N-GN, suggesting that the porous Co nanospheres are in-situ anchored on N-GN. Taking the combined advantages of magnetic porous Co nanospheres and dielectric lightweight N-GN, the Co/N-GN nanocomposites perform improved electromagnetic wave absorption abilities, such as high-efficiency absorption performance, thin matching thickness and broad effective absorption bandwidth. When the absorber thickness of nanocomposites is only 1.3 mm, the maximum reflection loss (RL) value can reach −24.3 dB at 17.7 GHz. And the effective absorption frequency with RL