Facile Fabrication of Three-Dimensional Lightweight RGO/PPy Nanotube/Fe₃O₄ Aerogel with Excellent Electromagnetic Wave Absorption Properties

Abstract

In this article, a three-dimensional chemically reduced graphene oxide/polypyrrole nanotubes (PPy nanotubes)/Fe 3 O 4 aerogel (GPFA) was fabricated by a simple one-step self-assembly process through hydrothermal reduction. The addition of both PPy nanotubes and Fe 3 O 4 nanoparticles is aimed to avoid the aggregation of graphene sheets, effectively adjust the permittivity, and make better impedance matching between dielectric loss and magnetic loss of the composite aerogel to gain excellent electromagnetic (EM) wave absorption performance. The EM wave-absorbing results indicate that the ternary composite with an ultralow density of about 38.3 mg/cm 3 shows an improved EM wave-absorbing property with a maximum reflection loss of −49.2 dB at the frequency of 11.8 GHz, with an effective absorption bandwidth below −10 dB reaching 6.1 GHz (9.8–15.9 GHz) at a thickness of 3.0 mm. Such an outstanding EM wave absorption behavior can be attributed to the multiple reflections, polarizations, and relaxation processes in the aerogel.

Reduced Graphene Oxide/Fe3O4/Polyaniline Ternary Composites as a Superior Microwave Absorber in the Shielding of Electromagnetic Pollution

“…Alternatively, enhancements in electronic polarization, interfacial polarization, and magnetic loss could increase the EM absorption properties of RGO/Fe 3 O 4 /PANI due to improved impedance matching. 46 , 51 , 52 The incident EM waves are also likely to undergo multiple reflections and scattering due to the presence of interfaces between RGO/Fe 3 O 4 , Fe 3 O 4 /PANI, and RGO/PANI. RGO sheets of high specific area could also result in the absorption of EM waves and account its absorption following the dissipation of their energy as heat.…”

“…In view of this, attenuation of EM waves have also been achieved in fabricating ternary composites derived from different permutation combination of conducting polymers, graphene, and Fe 3 O 4 , such as, graphene/Fe 3 O 4 incorporated polyaniline (PANI), 44 PANI nanorod/Fe 3 O 4 microspheres on graphene nanosheets, 45 graphene/polypyrrole (PPY)/Fe 3 O 4 , 46 N-doped graphene@PANI nanorod arrays hierarchical structures modified by Fe 3 O 4 nanoclusters, 47 and graphene/PPY/Fe 3 O 4. 48 In addition, RGO-based ternary composites comprising Fe 3 O 4 and PANI (or PPY) have also been studied in electromagnetic shielding interference applications, such as PANI-coated Fe 3 O 4 /reduced graphene, 49 RGO-magnetic porous nanospheres-PANI, 50 RGO/PPY nanotube/Fe 3 O 4 aerogel, 51 RGO-PANI-Co 3 O 4, 52 PPY-RGO-Co 3 O 4, 53 RGO/Fe 3 O 4 /PANI, 54 γ-Fe 2 O 3 /(SiO 2 ) x –SO 3 H/PPY core/shell/shell microspheres 55 for the application of electromagnetic interference shielding.…”

Tunable, large X-band microwave absorbers using variable chessboard surfaces

“…In the present study, the rGO/Fe3O4/PPy composite reported by Zhang et al [6] was used as coating material. The PPy and the addition of Fe3O4 adjust the permittivity and improve the impedance matching between the dielectric and the magnetic losses which allows the EM wave to penetrate the material and its subsequent dissipation as thermal energy.…”

“…However, despite the large absorption peaks achieved in the literature, most of the studied metamaterials show a narrow absorption bandwidth, therefore, many efforts have been made to extend the bandwidth and cover wider bands of the electromagnetic spectrum [3][4][5]. For example, a 3 mm coating of a composite made of reduced graphene oxide (rGO), magnetite (Fe3O4) and polypyrrole (PPy) has a reported maximum absorption of -49.2 dB at 11.8 GHz, with a maximum effective absorption i.e., attenuation above -10 dB in the studied band, of -28.76 dB/GHz [6]. Some strategies to increase the bandwidth are the use of multilayer materials [7,8], although they could suffer delamination due to interfacial stress during wearing.…”

Nitrogen‐Doping‐Regulated Electromagnetic Wave Absorption Properties of Ultralight Three‐Dimensional Porous Reduced Graphene Oxide Aerogels

“…Recently, 3D RGO aerogels and RGO‐based composite aerogels have been regarded as potential lightweight EMW absorbents because of their unique porous structure, large specific surface area, and ultralow density. [ 18–29 ] For instance, Liu et al. fabricated a 3D graphene/polypyrrole aerogel (GPA) by a simple one‐step reduction self‐assembly process, and found that the composite aerogel with a filler content (ϕ w ) of 50 wt% displayed the minimum reflection loss (RL min ) of –51.12 dB at 6.4 GHz, and effective absorption bandwidth (EAB, RL less than –10 dB) of 5.88 GHz under a matching thickness ( d ) of 3 mm.…”