Facile synthesis of Co/SC microwave absorbents by recycling coal hydrogasification residue

Gao, Fei; Li, Yuyan; Mao, Lutao; Wang, Yake; Zhu, Baoshun; Liang, Liping; Li, Guomin; Zhang, Rong

doi:10.1016/j.matlet.2021.131168

Cited by 11 publications

(6 citation statements)

References 12 publications

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“…For a deep understanding of the microwave response mechanism, the frequency ( f )-dependency curves of ε r and μ r are shown in Figure a,b. Generally, the electromagnetic parameters are the fundamental roots to the outstanding MAPs of an absorber. , The real part (ε′, μ′) of ε r and μ r separately reflect the storage ability of the electric and magnetic energy, and the corresponding imaginary part (ε′′, μ′′) denotes the dissipation capacity of electromagnetic energy Figure a shows that the whole ε′– f and ε′′– f curves tend to monotonically decrease, accompanied by some mild fluctuations.…”

Section: Results and Discussionmentioning

confidence: 99%

Facile Synthesis of Fe_xO_y/C-Based Microwave Absorption Composites under Elevated-Temperature Heat Treatment for the High-Value Utilization of Red Mud

Xue,

Su,

Jia

et al. 2024

ACS Appl. Electron. Mater.

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To achieve the high-value utilization of solid waste red mud and the low-cost preparation of efficient microwave absorbers, we recycled red mud (RM) and coal (C) to economically synthesize Fe x O y /C-based microwave absorbers (named RMCs) via a one-pot method and carbothermal reduction technology. It was found that the magnetic species and carbon crystallinity are sensitive to the carbothermal temperature. Interestingly, the microwave absorption performances of RMC composites display strong inclusiveness to the variable magnetic components with temperature. Benefiting from the suitable magnetic species and graphitization degree of carbon, excellent microwave absorption properties are achieved in the RMC composites. For RMC-700 composites, all of the minimum reflection loss (RL min ) values are less than −30 dB when the coating thickness is above 1.5 mm, and its maximum efficient absorption bandwidth (EAB max ) covers five-sixths of the Ku band (5 GHz). For RMC-900 samples with a coating thickness of 1.5 mm, the RL min value could reach −25 dB with a corresponding EAB of 4.16 GHz. An RL min value of −34.6 dB and an EAB max of 4.08 GHz are also obtained in RMC-1000 composites. The above excellent properties are mainly benefited by the strong dielectric loss, which is derived from Fe and its oxide particles as well as graphitized carbon. Moreover, multiple interface polarization and dipole polarization loss provide a guarantee for the powerful attenuation capability of the RMC composite. Impedance matching is also effectively regulated by the changeable magnetic constituents. More importantly, this work provides a direction for the application of recycled red mud, further reducing the environmental pollution caused by its stacking, and is expected to make certain contributions toward protection against electromagnetic radiation.

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Section: Results and Discussionmentioning

confidence: 99%

Facile Synthesis of Fe_xO_y/C-Based Microwave Absorption Composites under Elevated-Temperature Heat Treatment for the High-Value Utilization of Red Mud

Xue,

Su,

Jia

et al. 2024

ACS Appl. Electron. Mater.

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“…The electromagnetic absorption performance of the absorber is closely related to the relative complex permittivity ( ε r = ε ′– jε ″) and the complex permittivity ( μ r = μ ′– jμ ″), where the real part ( ε ′ and μ ″) represents the storage capacity of electric and magnetic energy, respectively, whereas the imaginary part ( ε ″ and μ ″) represents the dissipation capacity of electric and magnetic energy, respectively. [ 34–36 ]…”

Section: Resultsmentioning

confidence: 99%

Magnetic Carbon Composites Derived from Coal Hydrogasification Residue for Microwave Absorption

Mao

Liang

et al. 2022

Physica Status Solidi (a)

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To cut the cost of microwave absorption materials (MAMs) and achieve the recycling of semicoke (SC), the by‐product in coal hydrogasification process, SC was applied to prepare composite MAMs. The facile synthesis process involves liquid‐phase impregnation, and then in situ carbothermal reduction treatment. Champion sample prepared under 800 °C (FeSC800) exhibits the minimum reflection loss (RLmin) of −39.3 dB under a coating thickness of 2.5 mm, and the effective absorption bandwidth (EAB) can reach 3.9 GHz (14.1–18 GHz) at a coating thickness of 1.5 mm. The enhancement of interfacial and dipole polarization, as well as the synergistic effect between the dielectric properties of SC matrix and the magnetic properties of Fe particles, can account for the excellent microwave absorption (MA) performance. In view of the source of SC matrix, the prepared FeSC800 was not only expected to become a candidate in the field of MAMs, but also presented a promising approach for the resource utilization of SC.

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“…29 These features contribute to conductive, polarization, and magnetic losses as well as multiple occurrences of reflection and scattering, respectively. For example, Gao et al 29 used a Co/SC composite as a microwave absorber. The Co/SC content of 60% used in their study afforded an excellent MA performance of the composites with paraffin as the matrix.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Compared with their direct utilization, the use of the residue or waste left behind after the extraction of active ingredients such as natural gas is considered as a more efficient and environment-friendly strategy. SC, a solid waste produced during the hydrogasification of coal, has a considerably high production rate of 40–50% and a well-developed pore structure, which make this material suitable as an organic pollutant-absorption material or for further hydrogasification. , In addition, SC is an ideal MAM owing to its inherent advantageous properties, including favorable graphitization, residual heterogeneous atoms, minor magnetic components, and a well-developed pore structure . These features contribute to conductive, polarization, and magnetic losses as well as multiple occurrences of reflection and scattering, respectively.…”

Section: Introductionmentioning

confidence: 99%

“…27,28 In addition, SC is an ideal MAM owing to its inherent advantageous properties, including favorable graphitization, residual heterogeneous atoms, minor magnetic components, and a well-developed pore structure. 29 These features contribute to conductive, polarization, and magnetic losses as well as multiple occurrences of reflection and scattering, respectively. For example, Gao et al 29 used a Co/SC composite as a microwave absorber.…”

Section: ■ Introductionmentioning

confidence: 99%

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Fabrication of Flexible Thermoplastic Polyurethane/Coal Hydrogasification Semi-coke Composites with Low rGO Content for High-Performance Microwave Absorption

et al. 2022

ACS Appl. Electron. Mater.

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Semi-coke (SC), a residue of coal hydrogasification, is recycled and incorporated into thermoplastic polyurethane (TPU) to create composites for microwave absorption (MA). Herein, we developed porous reduced SC (rSC)−reduced graphene oxide (rGO) hybrids (SGHs) via in situ reduction of a preoxidized SC (oSC) and graphene oxide (GO) mixture. Lowcontent GO was introduced to considerably improve the dielectric properties of SGHs while decreasing the production cost. Then, a solution blending technique was applied to develop microwave absorbers using TPU as the matrix. The obtained TPU/SGH5 composite with a feed ratio of 5:1 (oSC:GO) showed an optimum reflection loss of −48.81 dB at a thickness of 2.5 mm and an effective absorption bandwidth of 4.30 GHz (7.74−12.04 GHz) in 2−18 GHz. However, the MA property of the obtained composites with the same amount of rSC or rGO alone was not comparable to that of the TPU/SGH5 composite. The inherent magnetism, heteroatoms, and abundance of heterogeneous surfaces of rSC and the considerable dielectric loss of rGO worked together to improve the MA performance of TPU/SGH composites. This study offers an easy and effective technical method for producing high-performance microwave absorbers with a low rGO content, illuminating the path toward achieving sustainable development by converting waste into wealth.

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Facile synthesis of Co/SC microwave absorbents by recycling coal hydrogasification residue

Cited by 11 publications

References 12 publications

Facile Synthesis of Fe_xO_y/C-Based Microwave Absorption Composites under Elevated-Temperature Heat Treatment for the High-Value Utilization of Red Mud

Facile Synthesis of Fe_xO_y/C-Based Microwave Absorption Composites under Elevated-Temperature Heat Treatment for the High-Value Utilization of Red Mud

Magnetic Carbon Composites Derived from Coal Hydrogasification Residue for Microwave Absorption

Fabrication of Flexible Thermoplastic Polyurethane/Coal Hydrogasification Semi-coke Composites with Low rGO Content for High-Performance Microwave Absorption

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Facile synthesis of Co/SC microwave absorbents by recycling coal hydrogasification residue

Cited by 11 publications

References 12 publications

Facile Synthesis of FexOy/C-Based Microwave Absorption Composites under Elevated-Temperature Heat Treatment for the High-Value Utilization of Red Mud

Facile Synthesis of FexOy/C-Based Microwave Absorption Composites under Elevated-Temperature Heat Treatment for the High-Value Utilization of Red Mud

Magnetic Carbon Composites Derived from Coal Hydrogasification Residue for Microwave Absorption

Fabrication of Flexible Thermoplastic Polyurethane/Coal Hydrogasification Semi-coke Composites with Low rGO Content for High-Performance Microwave Absorption

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Facile Synthesis of Fe_xO_y/C-Based Microwave Absorption Composites under Elevated-Temperature Heat Treatment for the High-Value Utilization of Red Mud

Facile Synthesis of Fe_xO_y/C-Based Microwave Absorption Composites under Elevated-Temperature Heat Treatment for the High-Value Utilization of Red Mud