Graphene-carbonyl iron cross-linked composites with excellent electromagnetic wave absorption properties

Graphene is a highly desirable material for efficient electromagnetic wave absorption due to its strong dielectric loss and low density. However, the main drawbacks in pristine graphene, such as high dielectric constant and low permeability, inevitably limit its performance due to the poor impedance matching. In this paper, reduced graphene oxide spherical carbonyl iron composites (RGO-SCI) have been successfully fabricated through a facile wet chemical method. As expected, an apparent improvement of impedance matching in electromagnetic wave absorption could be found through the combination of RGO and SCI. A carbon-bridge effect was adopted to explain the electromagnetic wave absorbing process, which is closely related to a cross-linked framework structure of as-synthesized composites. Besides, in the range of 7.79-11.98 GHz with the thickness of 3.0 mm, the RGO-SCI composites exhibited efficient electromagnetic wave absorption characteristics (RL < 10 dB) with a minimum reflection loss of -52.46 dB.