Controllable permittivity in 3D Fe₃O₄/CNTs network for remarkable microwave absorption performances

Abstract

Fe3O4 porous spheres are anchored onto carbon nanotubes (CNTs) to form three-dimension Fe3O4/CNTs nanocomposites, which exhibit remarkable EM microwave absorption performances with RL value of −51 dB at 5.52 GHz and effective bandwidth of 3.9 GHz.

Boosted Interfacial Polarization from Multishell TiO2@Fe3O4@PPy Heterojunction for Enhanced Microwave Absorption

“…In addition, the moderate attenuation constant and impendence matching also make the TF@PPy composite a prospect candidate for the excellent MA material (Figure S4, Supporting Information). Compared with other relative absorbers ( Table ), the hierarchical TF@PPy composite demonstrates considerable merits such as enhanced absorption properties, adjustable absorption frequency, and thin coating thickness (Figure g–i), which cater to the requirements of wider applicability in the microwave absorption . As mentioned above, the involved microwave absorption mechanisms can be divided into the following aspects ( Scheme ): a)Polarization loss: By comparing with TiO 2 @Fe 3 O 4 , the complex permittivity of TF@PPy increases significantly, demonstrating the excellent dielectric properties (Figure a,b).…”

Template‐Free Formation of Uniform Fe3O4 Hollow Nanoflowers Supported on Reduced Graphene Oxide and Their Excellent Microwave Absorption Performances

“…Furthermore, the MHF are supported and tightly anchored on the two‐dimensional reduced graphene oxide sheets due to the large contact surface and abundant functional groups of rGO sheets . The high‐conductivity rGO sheets across the whole composites and tightly bind the MHF, which can enhance their microwave absorption performances . Generally, the incident EM microwaves can be dissipated and absorbed as a result of being repeatedly scattered and reflected between the interfaces.…”

One‐Pot Hydrothermal Synthesis of Co3O4/MWCNTs/Graphene Composites with Enhanced Microwave Absorption in Low Frequency Band

“…The enhanced microwave absorption performance of Co 3 O 4 /MWCNTs/Graphene ternary composite is mainly attributed to a number of factors as shown in Scheme . Firstly, with the addition of the graphene and MWCNTs, the impedance matching was enhanced due to the synergistic effect of the dielectric and magnetic loss, so that more electromagnetic wave can enter into the inner of composite to be dissipated . Secondly, the porous structure of the composite can enhance the multi‐scattering of electromagnetic wave during the transfer process.…”

“…Firstly, with the addition of the graphene and MWCNTs, the impedance matching was enhanced due to the synergistic effect of the dielectric and magnetic loss, so that more electromagnetic wave can enter into the inner of composite to be dissipated. [27] Secondly, the porous structure of the composite can enhance the multi-scattering of electromagnetic wave during the transfer process. This will be also helpful to improve microwave absorption.…”

“…The maximum reflection loss values of the composites were À 44.5 dB, À 43.5 dB and À 46.5 dB corresponding to the component consisting of polyaniline, polypyrrole and poly (3,4-ethyendioxythiophene) respectively. Zhu et al [27] anchored Fe 3 O 4 porous spheres onto the surface of CNTs by a simple solvothermal method and the as-prepared nanocomposites showed a threedimension network. The high surface areas and porous structure of magnetic Fe 3 O 4 spheres presented a good synergetic with CNTs.…”