Enhanced electromagnetic wave absorption of Fe3O4@MnO2@Ni–Co/C composites derived from Prussian blue analogues

Abstract

Herein, Fe₃O₄@MnO₂@Ni–Co/C composites derived from PBAs were successfully fabricated. Firstly, Ni–Co Prussian blue analogues (Ni–Co PBAs) were used as precursors to derive a carbon layer on their surface by annealing treatment and subsequently translated into MnO₂@Ni–Co/C nanocubes after hydrothermal reactions. Fe₃O₄@MnO₂@Ni–Co/C composites were finally obtained after depositing Fe₃O₄ nanoparticles through the annealing process. Their electromagnetic wave (EMW) absorption performance apparently enhanced, thanks to the excellent impedance matching and strong attenuation derived from the synergy between the dielectric loss and the magnetic loss. In particular, the minimum reflection loss (RL_min) of Fe₃O₄@MnO₂@Ni–Co/C reached −41.2 dB with a thickness of 4.0 mm and the effective absorption bandwidth (EAB) reached 7.1 GHz with a thickness of 2.0 mm. Therefore, the results could be significant for synthesizing EMW absorbers with excellent performance, a broad bandwidth, strong absorption, thin thickness and light weight.