Ternary Mo2C/Co/C composites with enhanced electromagnetic waves absorption

Wang, Yahui; Li, Xuandong; Han, Xijiang; Xu, Ping; Cui, Liru; Zhao, Honghong; Liu, Dawei; Wang, Fengyuan; Du, Yunchen

doi:10.1016/j.cej.2020.124159

Cited by 138 publications

(72 citation statements)

References 81 publications

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“…And the RL value of − 10 dB refers to 90% of incident EMWs can be converted into thermal energy. Correspondingly, the frequency range in which RL value is smaller than − 10 dB stands for the effective absorption bandwidth [ 60 ]. On the basis of transmission line theory, the specific calculation process from electromagnetic parameters to RL is expressed as the followed formulas [ 61 , 62 ]: where f is the frequency, d is the matching thickness, c is the velocity of light in vacuum, and Z 0 and Z in are the free space impedance and the input impedance of absorbers, respectively.…”

Section: Theories Of Electromagnetic Wave Absorptionmentioning

confidence: 99%

Carbon-Based MOF Derivatives: Emerging Efficient Electromagnetic Wave Absorption Agents

et al. 2021

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To tackle the aggravating electromagnetic wave (EMW) pollution issues, high-efficiency EMW absorption materials are urgently explored. Metal–organic framework (MOF) derivatives have been intensively investigated for EMW absorption due to the distinctive components and structures, which is expected to satisfy diverse application requirements. The extensive developments on MOF derivatives demonstrate its significantly important role in this research area. Particularly, MOF derivatives deliver huge performance superiorities in light weight, broad bandwidth, and robust loss capacity, which are attributed to the outstanding impedance matching, multiple attenuation mechanisms, and destructive interference effect. Herein, we summarized the relevant theories and evaluation methods, and categorized the state-of-the-art research progresses on MOF derivatives in EMW absorption field. In spite of lots of challenges to face, MOF derivatives have illuminated infinite potentials for further development as EMW absorption materials.

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Section: Theories Of Electromagnetic Wave Absorptionmentioning

confidence: 99%

Carbon-Based MOF Derivatives: Emerging Efficient Electromagnetic Wave Absorption Agents

et al. 2021

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“…Interestingly, the negative μʹʹ values from 8.7 to 18 GHz www.advelectronicmat.de are detected, evidenced by the stronger induced magnetic field than the initial it under the alternating electromagnetic field. [46,47] As displayed in Figure 4f, tanδμ gives the similar tendency as μʹʹ. It is widely accepted that the magnetic loss is due to the eddy current loss, natural resonance and exchange resonance.…”

Section: Resultsmentioning

confidence: 77%

High‐Efficiency Microwave Attenuation of Magnetic Carbon Nanoparticle‐Decorated Tubular Carbon Nanofibers Composites at an Ultralow Filling Content

Kang

Qiao

Cao

et al. 2021

Adv Elect Materials

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Faced with the formidable challenge to achieve a powerful absorption and broad bandwidth under a thin response thickness at a low filler content, tailoring the composition and microstructure of the absorbers is generally regarded as a potential method to tackle it. In the study, unprecedented tubular carbon nanofiber/Co/nanoporous carbon (TCNFs/Co/NPC) hybrids with rich holes are obtained by the direct thermal treatment of tubular polymer nanofibers/ZIF-67 (TPNFs/ZIF-67) precursor, which is fabricated by controllable anchor of ZIF-67 nanocrystals on the surface of sulfonated TPNFs (TPNFs-SO 3 H). The dielectric parameters of the resultant samples are reasonably monitored by adjustable TPNFs-SO 3 H dosage and filling content. Benefiting from the dielectric-magnetic compositions and unique heterogeneous and porous configurations, the boosted impedance matching and polarization relaxation are given. Hence, under an ultralow filling content of 8 wt%, a minimum reflection loss (RL min ) value of −54.1 dB corresponding to a matching thickness of 2 mm and an effective absorption bandwidth (EAB) of 6.2 GHz at 2.5 mm are exhibited at the TPNFs-SO 3 H usage of 100 mg and carbonization temperature of 700 °C, respectively. This work provides an instructive guidance for constructing highly efficient absorbers with strong attenuation and wide frequency range at a low thickness.

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“…In that case, the thickness of MAMs and the frequency of minimum absorption peak may satisfy Eq. 5 [33,64]:…”

Section: Microwave Absorption and Mechanismmentioning

confidence: 99%

“…It is well known that either SiC or Ti 3 C 2 has very large particle size even up to several microns, which means that these carbides particles cannot fully contact with carbon matrix, and thus, the contribution from interfacial polarization may be insufficient in such carbon/carbide composites [29,32]. More recently, some attempts were made to decorate carbon matrix with some unconventional carbide particles, whose ultrafine particle size could generate good dispersion and abundant interfaces, resulting in a significant enhancement in microwave absorption [33][34][35][36][37]. For example, Dai et al pioneered the involvement of Mo 2 C nanoparticles in carbon matrix through the pyrolysis of Cu-Mo-based metal organic frameworks (MOFs) and the subsequent removal of Cu species, and they confirmed that the synergistic effect of carbon frameworks and Mo 2 C nanoparticles were responsible for the good reflection loss (RL) characteristics [34].…”

Section: Introductionmentioning

confidence: 99%

Solvent-Free Synthesis of Ultrafine Tungsten Carbide Nanoparticles-Decorated Carbon Nanosheets for Microwave Absorption

et al. 2020

Self Cite

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HIGHLIGHTS • Ultrafine tungsten carbide nanoparticles-decorated carbon nanosheets were successfully fabricated via a simple solvent-free strategy. • The chemical composition of tungsten carbide/carbon composites can be easily manipulated by the weight ratio of dicyandiamide to ammonium metatungstate. • The advantages in good performance and simple preparation provide a promising prospect for the application of these tungsten carbide/ carbon composites. ABSTRACT Carbides/carbon composites are emerging as a new kind of binary dielectric systems with good microwave absorption performance. Herein, we obtain a series of tungsten carbide/carbon composites through a simple solvent-free strategy, where the solid mixture of dicyandiamide (DCA) and ammonium metatungstate (AM) is employed as the precursor. Ultrafine cubic WC 1−x nanoparticles (3-4 nm) are in situ generated and uniformly dispersed on carbon nanosheets. This configuration overcomes some disadvantages of conventional carbides/carbon composites and is greatly helpful for electromagnetic dissipation. It is found that the weight ratio of DCA to AM can regulate chemical composition of these composites, while less impact on the average size of WC 1−x nanoparticles. With the increase in carbon nanosheets, the relative complex permittivity and dielectric loss ability are constantly enhanced through conductive loss and polarization relaxation. The different dielectric properties endow these composites with distinguishable attenuation ability and impedance matching. When DCA/AM weight ratio is 6.0, the optimized composite can produce good microwave absorption performance, whose strongest reflection loss intensity reaches up to − 55.6 dB at 17.5 GHz and qualified absorption bandwidth covers 3.6-18.0 GHz by manipulating the thickness from 1.0 to 5.0 mm. Such a performance is superior to many conventional carbides/carbon composites.

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Ternary Mo2C/Co/C composites with enhanced electromagnetic waves absorption

Cited by 138 publications

References 81 publications

Carbon-Based MOF Derivatives: Emerging Efficient Electromagnetic Wave Absorption Agents

Carbon-Based MOF Derivatives: Emerging Efficient Electromagnetic Wave Absorption Agents

High‐Efficiency Microwave Attenuation of Magnetic Carbon Nanoparticle‐Decorated Tubular Carbon Nanofibers Composites at an Ultralow Filling Content

Solvent-Free Synthesis of Ultrafine Tungsten Carbide Nanoparticles-Decorated Carbon Nanosheets for Microwave Absorption

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