Magnetic carbon fiber/reduced graphene oxide film for electromagnetic microwave absorption

Abstract

Adding 10 wt% carbon fiber (CF) into graphene oxide (GO) dispersion were performed to fabricate CF10/reduced graphene oxide (rGO) film without the use of surfactants, binders or polymer matrices. The all-carbon CF10/rGO film possesses plausible tensile strength over one page of regular A4 printing paper and improved room-temperature ferromagnetism compared with the as-assembled rGO film, with saturation magnetization of about 0.327 emu/g and coercivity of about 100.4 Oe. The CF10/rGO composite with 50 wt% filler loading exhibits a good electromagnetic wave (EMW) absorption performance in the measured frequency range of 2–18 GHz. A minimal reflection loss reaches −34.3 dB@6.2 GHz (C-band), −35.4 dB@9.6 GHz (X-band), and −33.7 dB@13.1 GHz (Ku-band) with a thickness of 3.0 mm, 2.0 mm and 1.5 mm, respectively. The enhanced complex permittivity and permeability causing by the introduction of CF in rGO film are in favor of achieving an excellent impedance matching characteristic between the carbon materials and the air, responsible for more amount of EMW incidence; furthermore, localized electronic spin states and multi-relaxation processes arisen from the topological defects, oxygen-containing groups, and interfaces are ascribed to the enhanced microwave attenuation ability.