Facile Synthesis of Fe₃O₄/GCs Composites and Their Enhanced Microwave Absorption Properties

Abstract

Graphene has good stability and adjustable dielectric properties along with tunable morphologies, and hence can be used to design novel and high-performance functional materials. Here, we have reported a facile synthesis method of nanoscale Fe3O4/graphene capsules (GCs) composites using the combination of catalytic chemical vapor deposition (CCVD) and hydrothermal process. The resulting composite has the advantage of unique morphology that offers better synergism among the Fe3O4 particles as well as particles and GCs. The microwave-absorbing characteristics of developed composites were investigated through experimentally measured electromagnetic properties and simulation studies based on the transmission line theory, explained on the basis of eddy current, natural and exchange resonance, as well as dielectric relaxation processes. The composites bear minimum RL value of -32 dB at 8.76 GHz along with the absorption bandwidth range from 5.4 to 17 GHz for RL lower than -10 dB. The better performance of the composite based on the reasonable impedance characteristic, existence of interfaces around the composites, and the polarization of free carriers in 3D GCs that make the as-prepared composites capable of absorbing microwave more effectively. These results offer an effective way to design high-performance functional materials to facilitate the research in electromagnetic shielding and microwave absorption.

Heteronanostructured Co@carbon nanotubes-graphene ternary hybrids: synthesis, electromagnetic and excellent microwave absorption properties

“…Among these hybrids, heteronanostructured hybrids have been proved to exhibit strong EM wave absorption properties because of their interfacial and synergistic effects. Therefore, different categories of heteronanostructured hybrids were developed to further improve their EM wave absorbing capabilities, such as Fe@ZnO11, Fe 3 O 4 @SiO 2 12, Fe 3 O 4 @SnO 2 13, FeCo@ZnO14, Ni@TiO 2 15, and so on16171819. Generally, the previously reported results indicated that the microwave absorption (MA) capability of MAMs was mainly determined by the ε r , μ r , EM impedance matching and microstructure.…”

<strong>Preparation and characterization of MWCNT/Zn_0.25Co_0.75Fe₂O₄ nanocomposite and investigation of its microwave absorption properties at x-band by silicone rubber polymeric matrix</strong>

“…According to the transmission line theory, permeability and permittivity are the most important factors in the microwave absorbing properties that have been provided by magnetic nanoparticles, dielectric silicone rubber, and dielectric MWCNTs. Moreover, because of homogenous coating of nanoparticles base on the functionalized MWCNTs through the sonochemical and solvothermal complementary methods, interfacial polarization and Maxwell-Wagner effect was reinforced that enhanced charges accumulation and microwave absorption of sample [9,13]. Magnetic loss of the spinel ferrites because of eddy current loss effect and conductive loss of the MWCNTs according to the free electron theory caused the desirable microwave absorption in this nanocomposite [9,11].…”

“…Modified Ba 0.2 Sr 0.2 La 0.6 MnO 3 nanoparticles have absorbed 22.36 dB at 14.78 GHz and showed that can be a promissing microwave absorber between the other magnetic nanoparticles [1]. Recently, Polyaniline, polypyrrole, graphene, and carbon nanotube as the conductive polymers were used to dielecteric loss of the microwave absorbent nanocomposite [2,3,5,[9][10][11][12]. One of the most important factors having effect on the microwave attenuation is the polimeric matrix effect of the microwave absorbent samples.…”

Fe3C/helical carbon nanotube hybrid: Facile synthesis and spin-induced enhancement in microwave-absorbing properties

“…Exploration and preparation of high-performance microwave absorption materials is an effective approach to resolve the challenge related to EMI pollution. In practical application, excellent the microwave absorbing material usually has the advantages of low density, low thickness strong absorption at a broad frequency and high thermal stability [1]. At present, microwave absorbing material is one of typical functional materials and has a variety of applications in EMI shielding and countermeasure to radar detection [2,3].…”