Tailored design of -phenylenediamine functionalized graphene decorated with cobalt ferrite for microwave absorption.

Structural design and componential optimization are two primary directions in the study of microwave absorbers. In this study, a novel cobalt ferrite (CoFeO) decorated with -phenylenediamine (PPD) functionalized graphene (PG/CoFeO) binary hybrid with unique hierarchical porous structure was synthesized by a two-step route. The chemical composition, morphology and electromagnetic parameters of the as-prepared sample were investigated successively. The porous CoFeO microspheres with an average diameter of about 160 nm were uniformly anchored on rGO nanosheets. Owing to the uniquely hierarchical porous structure, synergistic effects of dielectric loss (conductive loss, interface and dipole polarization) and magnetic loss (eddy current loss, natural and exchange resonance), the as-prepared sample exhibited excellent microwave absorption (MA) performance. The maximum reflection loss (RL) could attain up to -53.3 dB, and the effective absorption bandwidth (EAB) reached 6.6 GHz (11.4-18.0 GHz) at 2.40 mm, which completely covered the band. These results showed that this functional material can be applied in the MA field.