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The reduced graphene oxide (RGO)/cobalt ferrite (CoFe 2 O 4 ) composites with three different (RGO)/(CoFe 2 O 4 ) ratios were synthesized by a one-pot hydrothermal route. To research the influence of graphene reduction degree on electromagnetic parameters of graphene composites, RGO/CoFe 2 O 4 -2 was treated further by reduction process with different reducing agents (N 2 H 4 /NaBH 4 ). The crystalline structure, morphology, thermal stability, magnetic property of the synthesized samples were characterized by XRD, TEM, SEM, FT-IR, Raman, TG, VSM and XPS. The absorption properties of the RGO/CoFe 2 O 4 composites were studied. The maximum R L of RGO/CoFe 2 O 4 -2 composite is −47.9 dB at 12.4 GHz with a thickness of 2.3 mm, and the absorption bandwidth with the R L below −10 dB is up to 5.0 GHz (from 12.4 to 17.4 GHz) with a thickness of 2.0 mm. The results indicated that the RGO/CoFe 2 O 4 composites have remarkably electromagnetic performance, which are attributed to effective complementarities between the dielectric loss and the magnetic loss. Additionally, the microwave absorption properties of the RGO/CoFe 2 O 4 composites can be tuned easily by varying the (RGO)/(CoFe 2 O 4 ) ratio, the reduction degree of graphene and layer thickness of the samples. [ABSTRACT FROM AUTHOR]

The electromagnetic wave absorption properties of the ternary nanocomposites consisting of graphene, poly (3,4-ethylenedioxythiophene) and Fe 3 O 4 nanoparticles had never been reported. Herein, in order to expand the scope of electromagnetic wave absorption materials, the nanostructured graphene/poly (3,4-ethylenedioxythiophene) hybrid materials with Fe 3 O 4 nanoparticles had been synthesized by a controllable co-precipitation method. The nanocomposites were characterized by FTIR, XRD, TEM, Raman spectroscopy, XPS and TG analysis. The investigation of the electromagnetic parameters revealed that the excellent electromagnetic wave absorption properties of the nanocomposites may be attributed to the improved impedance matching, the enhanced interfacial effects and the geometric effect. The maximum reflection loss of the nanocomposites was up to −56.5 dB at 8.9 GHz and the absorption bandwidths exceeding −10 dB were 3 GHz with a thickness of 2.9 mm. Furthermore, our development strategies expanded the scope of the electromagnetic wave absorption materials and confirmed that the modification of graphene with poly (3,4-ethylenedioxythiophene) and Fe 3 O 4 nanoparticles makes the nanocomposites have a promising future in electromagnetic wave absorption materials. [ABSTRACT FROM AUTHOR]

Highlights: [•] The ternary nanocomposites of GN–PANI–Fe3O4 were synthesized via a two-step method. [•] The size of Fe3O4 nanoparticles on GN–PANI is in the range of 5–20nm. [•] The maximum RL of GN–PANI–Fe3O4 is −43.9dB at 11.4GHz with a thickness of 2.5mm. [•] All the maximum RL was less than −24.2dB when the thicknesses vary from 2 to 4mm. [•] The bandwidths exceeding −10dB are 11.0GHz when the thicknesses in 2–4mm. [ABSTRACT FROM AUTHOR]