Surface-Oxidized Amorphous Fe Nanoparticles Supported on Reduced Graphene Oxide Sheets for Microwave Absorption

Abstract

A simple one-pot chemical reduction synthesis is provided to prepare a novel metal–graphene nanostructure, in which surface-oxidized amorphous Fe nanoparticles grow uniformly on reduced graphene oxide (rGO) sheets to form amorphous-Fe/rGO nanocomposites. A relatively low coercivity of 60.2 Oe is achieved in these magnetic graphene-based nanosheets supported with uniformly distributed amorphous Fe nanoparticles. The dielectric properties of amorphous-Fe/rGO nanocomposites are effectively tuned by suitable rGO additions. Improved impedance matching resulting from balanced magnetic and dielectric loss can be obtained in the Fe/5 wt % rGO nanocomposites, which results in their good wave absorption performance containing a high maximum reflection loss (−72.8 dB at 4.48 GHz) for a 3.26 mm thickness and a wide absorption bandwidth (5.90 GHz, <−10 dB). The simple synthesis, high structural stability, low density, and excellent wave absorption properties for amorphous-Fe/rGO nanocomposites enable their significant latent applications in lightweight electromagnetic microwave absorbers.

CoFe Nanoparticle-Decorated Reduced Graphene Oxide for the Highly Efficient Reduction of 4-Nitrophenol

“…For example, Lianbo Ma synthesized CoFe nanospheres decorated on N-doped carbon and investigated their electrochemical properties . Wu et al designed a one-pot synthesis method to fabricate Fe/reduced graphene oxide (RGO) nanocomposites, and in the nanocomposites, Fe NPs were uniformly decorated on RGO sheets . Zhang et al presented the preparation of Co-based NPs supported by graphene, which was encapsulated in nitrogen-doped graphitic layers for oxygen reduction reaction applications .…”

“…7 Wu et al designed a one-pot synthesis method to fabricate Fe/reduced graphene oxide (RGO) nanocomposites, and in the nanocomposites, Fe NPs were uniformly decorated on RGO sheets. 14 Zhang et al presented the preparation of Co-based NPs supported by graphene, which was encapsulated in nitrogen-doped graphitic layers for oxygen reduction reaction applications. 15 These investigations highlight the wide range of interactions between magnetic metal NPs and carbon-based auxiliary materials.…”

High-Performance, Lightweight, and Flexible Thermoplastic Polyurethane Nanocomposites with Zn2+-Substituted CoFe2O4 Nanoparticles and Reduced Graphene Oxide as Shielding Materials against Electromagnetic Pollution

“…113 For the determination of the electromagnetic wave absorption by the shielding material, better impedance matching resulting from a balance between permeability and permittivity is also required. 114 In general, the electromagnetic wave absorption level of the shielding material is determined by impedance matching. The value of Z = |Z in / Z o | can provide the degree of impedance matching.…”

“…The value of the attenuation constant is not the only prerequisite for excellent electromagnetic shielding characteristics . For the determination of the electromagnetic wave absorption by the shielding material, better impedance matching resulting from a balance between permeability and permittivity is also required . In general, the electromagnetic wave absorption level of the shielding material is determined by impedance matching.…”

Facile One-Pot Solvothermal Synthesis of the RGO/MWCNT/Fe3O4 Hybrids for Microwave Absorption

“…Carbon-based materials, including graphene, carbon nanotube (CNT), carbon black, and carbon fiber, show absorption performance with lightweight, high specific surface area, and tunable properties of permittivity, electrical, and thermal conductivity. − In addition, the carbon-based materials show many other applications, such as membrane materials, cathodes, supercapacitors, carbon-reinforced polymer composites, uranium adsorption materials, , anticorrosion materials, dye-sensitized solar cells, lithium-ion batteries, biosensors, thermal conductive materials, antiwear materials, and ceramic nanocomposites . Nevertheless, carbon materials are unilateral dielectric materials with high permittivity value and possess no magnetism, resulting in impedance mismatch, which limits the improvement of the MA performance.…”