Magnetic graphene composite aerogel for highly efficient electromagnetic wave absorption and anti-corrosion

Electromagnetic wave absorption materials inevitably encounter corrosive conditions during service, making corrosion-resistant design essential for their practical deployment. Herein, magnetic graphene composite aerogel (reduced graphene oxide (rGO)/ porous hollow Ni/C microspheres (PHNiC)) is fabricated via self-assembly of PHNiC and graphene oxide, followed by chemical reduction and freeze-drying. The rGO/PHNiC aerogel demonstrates excellent impedance matching and electromagnetic attenuation, achieving a minimum reflection loss of −51.3 dB at a thickness of 2.5 mm and a broad effective absorption bandwidth of 6.64 GHz. In addition, the conformal encapsulation of magnetic nanoparticles with rGO establishes a corrosion-mitigating barrier through interfacial passivation, effectively suppressing electrolyte penetration and anodic dissolution. Consequently, the rGO/PHNiC aerogel exhibits significantly improved corrosion resistance, with a corrosion potential of –0.45 V vs. saturated calomel electrode and a corrosion current density of 3.3 μA, demonstrating over 90 % reduction in corrosion rate compared to uncoated counterparts. This study provides valuable insights for the design of microwave absorbing materials that function in complex environments.