Hollow Beaded Fe₃C/N-Doped Carbon Fibers toward Broadband Microwave Absorption

Abstract

Microwave-absorbing materials have attracted enormous attention for electromagnetic (EM) pollution. Herein, hollow beaded Fe3C/N-doped carbon fibers (Fe3C/NCFs) were synthesized through convenient electrospinning and subsequent thermal treatment. The special hollow morphology of the samples is conducive to achieve lightweight and broadband microwave absorption properties. The thermal treatment temperatures exhibit a significant impact on conductivity and EM properties. The broadest effective absorption bandwidth (EAB) is 5.28 GHz at 2.16 mm when the thermal treatment temperature is 700 °C, and the EAB can cover 13.13 GHz with a tunable absorber thickness from 1.0 to 3.5 mm when the thermal treatment temperature is 750 °C. The excellent microwave absorption properties of the samples are due to the synergistic effect of impedance matching and strong EM energy attenuation abilities. Hence, the magnetic hollow beaded Fe3C/NCFs are expected to be an attractive candidate material as a lightweight and efficient microwave absorber in the future.

The excellent electromagnetic wave absorbing properties of carbon fiber composites: the effect of metal content

“…26 For instance, hollow beaded Fe 3 C/N-doped CNFs gained an effective absorption bandwidth of 5.28 GHz at 2.16 mm. 27 Wang et al 28 synthesized a hierarchical nest-like structure derived from CoFe-MOF-74 nanorods with different molar ratios of Co/Fe, achieving a minimum RL of −61.8 dB and a broad bandwidth of 9.2 GHz at 2.8 mm with a low filler loading of 10 wt%. Furthermore, our research group also prepared Fe III -MOF-5-derived/CNF composites, which exhibited a minimum RL of −39.2 dB and a bandwidth of 4.44 GHz at a small matching thickness of 1.4 mm.…”

An Equivalent Substitute Strategy for Constructing 3D Ordered Porous Carbon Foams and Their Electromagnetic Attenuation Mechanism

“…For polarization loss, the main contribution can be ascribed to interface polarization and dipole polarization, because the electron/ion displacement polarization phenomenon doesn’t seem to have an impact on ε r . In order to clarify the source of dielectric loss of the EDCF samples, the conduction loss and polarization loss should be analyzed in detail, which can be measured according to the following equation [ 62 , 63 ]: where represents the contribution of polarization loss; is the contribution of conduction loss; σ refers to the dielectric conductivity, and ε 0 ( ε 0 = 8.854 × 10 –12 F m −1 ) denotes the vacuum permittivity. The theoretical fitting calculation values of σ for various EDCF samples were shown in Fig.…”

“…For polarization loss, the main contribution can be ascribed to interface polarization and dipole polarization, because the electron/ion displacement polarization phenomenon doesn't seem to have an impact on ε r . In order to clarify the source of dielectric loss of the EDCF samples, the conduction loss and polarization loss should be analyzed in detail, which can be measured according to the following equation [62,63]:…”

Lightweight electromagnetic wave absorbent composites with Fe3O4 nanocrystals uniformly decorated on the surface of carbon spheres

“…[1][2][3][4][5] Electromagnetic wave absorption materials have gained widespread application in the fields of national defense security, electronic security, and healthcare. 6,7 Electromagnetic wave absorbent materials have shown a trend in advances in terms of compounds used, low-dimensionality, multi-spectrum compatibility, and intelligence. [8][9][10][11] Conventional electromagnetic wave absorbent materials can be divided into magnetic loss and dielectric loss materials.…”