Synthesis of nonstoichiometric Co0.8Fe2.2O4/reduced graphene oxide (rGO) nanocomposites and their excellent electromagnetic wave absorption property

In this paper, nonstoichiometric cobalt ferrite (Co0.8Fe2.2O4) and reduce graphene oxide (rGO) nanocomposites were synthesized by a facile one-pot hydrothermal method. The effect of rGO addition on the structure, morphology and magnetic properties of Co0.8Fe2.2O4/rGO nanocomposites was systematically investigated. Herein, owing to adjustable microstructure as well as the synergistic effects of Co0.8Fe2.2O4 and rGO, the electromagnetic (EM) wave absorption property of Co0.8Fe2.2O4/rGO nanocomposites can be well tunable by changing the addition amount of rGO. In comparison to pure Co0.8Fe2.2O4 ferrites, the introduction of rGO can greatly enhance EM wave absorption properties. Notably, the composite with the addition amount of 10 mg GO exhibits the minimum reflection loss (RL) of -51.2 dB at 11.4 GHz with the effective absorption bandwidth (<=-10 dB) 5.7 GHz when the absorber thickness is 2.1 mm. Meanwhile, when the addition amount of GO is 20 mg, a super-broad effective absorption bandwidth of the corresponding sample reaches 7.2 GHz from 10.8 to 18 GHz with a thickness of 2 mm. Owing to the good impedance matching and the synergistic effect between magnetic and dielectric loss, the as-synthesized Co0.8Fe2.2O4/rGO nanocomposites can be regarded as a new candidate for the lightweight EM wave absorber. (C) 2018 Elsevier B.V. All rights reserved.