Synthesis of three-dimensional graphene@nickel nanocrystals with high efficient microwave absorption

In recent years, the rapid advancement of military radar technology has driven the demand for microwave absorbing materials that are thin, wide, lightweight and strong absorption. This study employs a combined approach of solvothermal synthesis and high-temperature calcination to simultaneously achieve the self-assembly of three-dimensional reduced graphene oxide (rGO) and in-situ loading of magnetic nickel (Ni) nanoparticles without introducing reducing agents, resulting in the fabrication of a super-elastic three-dimensional rGO@Ni composite. Compared to pure rGO or Ni, the rGO@Ni composite demonstrates superior microwave absorption performance achieving a minimum reflection loss of −53.14 dB at 16.55 GHz with a matching thickness of only 2.5 mm. Notably, its effective absorption bandwidth (below −10 dB) reaches 7.99 GHz, covering the frequency range from 10.01 to 18 GHz. The results show that the rGO@Ni composite is promising candidate for microwave absorption.