Reduced Graphene Oxide-CoFe₂O₄/FeCo Nanoparticle Composites for Electromagnetic Wave Absorption

We have prepared reduced graphene oxide-CoFe2O4/FeCo nanocomposites with tunable and excellent absorbing properties through a simple one-step hydrothermal method. The obtained nanocomposites show magnetic particles with a diameter of ∼40 nm that are homogeneously wrapped by ∼5 nm thick graphene layers. Benefiting from its binary magnetic phases and the 3D dielectric-magnetic nanostructure, the nanocomposite shows microwave absorption performance with minimum reflection loss of −53.1 dB and broadened bandwidth of ∼7 GHz, which is superior to most carbon/magnet-based absorbers. This work may provide insights into developing high-performance hybrid absorbers with tunable frequency and broad absorption bandwidth via a facile coreduction preparation process and being more competitive in the commercialization of hybrid absorbers.