Materials Today Communications
·
2025
·
IF 4.5
Yuntong Wen,Hao Bian,Yongpeng Ran,Yonghao Xie,Minmin You,Huimin Wen,Liyun Shi,Jingquan Liu,Zude Lin
The 2D Ti 3 C 2 T x MXene anchored with magnetic particles has garnered significant attention due to its superior electromagnetic shielding performance and low reflection coefficient. However, current research on MXene-anchored magnetic particles faces several challenges, including complex fabrication processes, difficulty in controlling compositional ratios, the predominant use of spherical magnetic particles. In this work, by employing surfactants, FeCo alloy and Ni flakes were uniformly anchored onto MXene, the preparation process of the composite is simple and facilitates better control over the ratios of individual samples. Due to the unique structure formed by the intercalation of FeCo alloy and Ni flakes within the MXene layers, M-FC-N-35 exhibits an average electromagnetic shielding effectiveness of 61.2 dB within the Ku-band and maintains a reflection coefficient as low as 0.69. Additionally, the M-FC-N-35 composite was applied to the surface of the temperature sensor casing. It was found that under an electromagnetic field strength of 200 V/m and within a frequency range of 6–18 GHz, the temperature measurement deviation was reduced to 9.35 % of that of the sensor without the shielding material, demonstrating high electromagnetic interference resistance. This work provides guidance for simplifying the fabrication process of MXene composites with magnetic metals and enriching the system of electromagnetic shielding materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2024
·
IF 7.5
Feng Zhang,Yu Lei,Guang Li,Yangchen Xie,Xinjia Guo,Xiaoyan Zhang,Xianyou Wang
Graphical ORR or OER : CoFe layered double hydroxide (CoFe-LDH) nanosheets are deposited on nitrogen-doped graphite-carbon polyhedra with FeCo alloy nanoparticles to form a composite bifunctional oxygen electrocatalyst. The FeCo/LDH-NGCP catalyst shows wonderful ORR and OER bifunctional electrocatalytic performance, which is superior to that of the precious metal based catalyst. Reasonably screening the targeted oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) constituents and constructing high-efficiency and stabilized ORR/OER bifunctional electrocatalysts are pivotal for the advancement of rechargeable zinc-air batteries (ZABs). Here, CoFe layered double hydroxide (CoFe-LDH) nanosheets are deposited on nitrogen-doped graphite-carbon polyhedra with FeCo alloy nanoparticles (FeCo/LDH-NGCP). Due to the synergic effect between FeCo-NGCP, CoFe-LDH and FeCo/LDH-NGCP, the electrocatalyst with the abundant and accessible active sites can provide good charge/mass transfer, and thus shows wonderful ORR and OER bifunctional electrocatalytic performance. In ORR tests, FeCo/LDH-NGCP catalyst displays larger half-wave potential (E 1/2 , 0.89 V vs. 0.85 V), higher limiting current density (J L , 5.91 mA/cm 2 vs. 5.14 mA/cm 2 ) and better stability than commercial Pt/C. As for OER, FeCo/LDH-NGCP possesses a smaller overpotential (η) of 299.6 mV at a current density of 10 mA/cm 2 and more durable stability than commercial RuO 2 (330.6 mV). Furthermore, in ZAB tests, the cycling stability of ZAB-FeCo/LDH-NGCP (over 470 h) outperforms the ZAB-Pt/C+RuO 2 (92 h) with commercial electrocatalyst (Pt/C+RuO 2 ). Therefore, the FeCo/LDH-NGCP catalyst offers a new perspective to construct ZABs bifunctional catalysts and their commercial application in ZABs.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2023
·
IF 10.9
Junru Yao,Jintang Zhou,Lu Lu,Feng Yang,Zhengjun Yao,Bo Ouyang,Erjun Kan,Yuxin Zuo,Renchao Che,Fan Wu
Magnetic metal absorbers exhibit remarkable microwave absorption capacity. However, their practical application is severely limited due to their susceptibility to corrosion, particularly in marine environments. To address this challenge, we propose a novel approach involving the modification and control of FeCo/rGO microwave absorbers using rare earth lanthanum (La). This strategy aims to achieve both high-performance microwave absorption and enhanced resistance to marine corrosion. In this study, we employ a La 2 O 3 modifying control strategy to refine the FeCo magnetic particles and coat them with CoFe 2 O 4 on the surface, leveraging the pinning effect of in situ generated La 2 O 3 . This process enhances the interface polarization of the absorbers, thereby improving their electromagnetic performance and marine corrosion resistance . Consequently, the La 2 O 3 modified FeCo@rGO composites exhibit broadband absorption, covering a wide frequency range of 6.11 GHz at 1.55 mm. Notably, the electromagnetic properties of the La 2 O 3 modified FeCo@rGO absorbers remain stable even after prolonged exposure to a 3.5 wt% NaCl solution, simulating marine conditions, for at least 15 days. Furthermore, we perform first-principle calculations on FeCo and FeCo O to validate the corrosion resistance of the La 2 O 3 modified FeCo@rGO composites at the atomic level. This comprehensive investigation explores the control of rare earth lanthanum modification on the size of magnetic metal particles, enabling efficient electromagnetic wave absorption and marine corrosion resistance. The results of this study provide a novel and facile strategy for the control of microwave absorbers, offering promising prospects for future research and development in this field.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Zhaoying Yang,Xinge Wu,Gaowu Qin,Xiangying Meng
FeCo-N-C is considered a promising electrode material for hydrogen fuel cells. However, its oxygen reduction reaction (ORR) performance is limited by the strong adsorption of intermediates. In this work, we regulated the adsorption of “metal-intermediates” by modulating the interaction between the metal and support. The sulfur atoms were introduced to modify the periphery of the M-N x sites, and an atom-dispersed bimetallic site micro-mesoporous catalyst (FeCo-SN-C) was synthesized. The S dopant enhances the bonding between the metal catalytic sites and the support, which weakens the adsorption of ORR intermediates on catalytic sites, resulting in exceptional stability and ORR activity of the catalyst. ORR tests showed that FeCo-SN-C in 0.1 M KOH exhibited superior half-wave potential (0.863 V vs. RHE), which outperformed Pt/C (0.833 V), along with high stability and methanol tolerance. Theoretical calculations demonstrated that the doping of S effectively shifted the 3d electron orbital of the Fe site to a deeper level, optimized the adsorption and desorption energy barriers of the key oxygen-containing intermediate (∗OH), and promoted the ORR. Additionally, the Zn-air batteries based on FeCo-SN-C exhibited excellent discharge performance and durability. This study provides insights and solutions for the rational design of TM-N-C catalysts to enhance their activity and stability.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Yuancai Lv,Shiyu He,Shuting Liu,Zhendong Yu,Yanting Jiang,Yihui Hu,Yifan Liu,Chunxiang Lin,Xiaoxia Ye,Guifang Yang,Minghua Liu
Doping polymetals on Fe-based catalysts is proved to be an effective way to improve the performance on activating persulfate. In this paper, a highly efficient persulfate activation catalyst (FeCo@MoS 2 ) was successfully synthesized by introducing MoS 2 onto the surface of FeCo nanoboxes. During the activation of PMS the introduced of MoS 2 effectively promoted the formation of free radicals (∙OH, SO 4 · - ), 1 O 2 and Fe(IV). Due to the synergistic effects between Mo and Fe, FeCo@MoS 2 has better catalytic activity (2.01 times larger of defluorination efficiency and 3.91 times larger of the apparent rate constant ( k obs )) than FeCo. Under the optimal conditions (catalyst dosage of 0.2 g L −1 , PMS dosage of 1.0 g L −1 and initial pH 4.0), the perfluorooctanoic acid (PFOA, 10 mg L −1 ) could be degraded in 60 min, with 90.26 ± 2.64% of the defluorination efficiency. The LC- MS results showed that under the attack of free radicals (∙OH, SO 4 · - ), 1 O 2 and Fe(IV), the PFOA underwent step-by-step defluorination process. In addition, the ECOSAR results showed that during the whole degradation of PFOA in FeCo@MoS 2 /PMS system, no highly toxic intermediates was accumulated, suggesting a green degradation process. This work showed new ideas and strategies for studying the influence of polymetallic doping on the catalytic process of PMS multiphase catalytic system.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2021
·
IF 3.315
Yang Fan,Jingyu Wang,Ximing Zhang,Zaisheng Zhu,Yin Liu,Atian Xie,Hongcun Bai,Ling Bing Kong
The introduction of magnetic materials into carbon materials has been proved to be an effective approach to tailor and improve electromagnetic wave (EM) absorption. In this study, coal-based carbon/FeCo (CBC/FeCo) magnetic composites were designed and prepared. These samples exhibit layered stripes similar to graphite. In these novel composites, the FeCo alloy exhibits strong magnetic loss and the coal-based carbon (CBC) not only acts as an impedance matching medium but also exhibits excellent dielectric loss. Therefore, the CBC/FeCo composites exhibit strong EM absorption, with minimum reflection loss ( RL min ) of −60.81 and −49.82 dB at thicknesses ( d ) of 1.38 and 2.45 mm, respectively. Compared with pure coal-based carbon and FeCo alloy, the improvement in EM absorption can be mainly attributed to the improved impedance matching and enhanced multiple interfacial polarization . In addition, the effects of reaction temperature and the content of FeCo on EM absorption performance of the composites were also studied. Specifically, samples of S-2 with process temperature at 800 °C for 2 h and the FeCo alloy mass loading was 0.3 g (CBC/FeCo-0.3), the EM absorption performance was optimized. It is believed that the CBC/FeCo composites could be promising candidates for EM absorbers.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS RESEARCH
·
2022
·Vol. 37
·期 10
·1798-1809
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IF 2.909
Yu Qi,Liu Chaofan,Nie Weicheng,Chen Ping,Xue Yanan,Tang Yiming
A kind of reduced graphene oxide hollow microspheres loaded with FeCo alloy (AirRGO@FeCo) was synthesized by oil-in-water emulsification technology and high-temperature calcination process. By controlling the concentration of GO aqueous solution, five kinds of hollow microspheres with different RGO contents were synthesized. The diameter of the synthesized hollow microspheres was 4–6 μm, and the thickness of the spherical wall was 0.1–1 μm adjustable. As the concentration of GO aqueous solution is 6 mg/ml, the AirRGO@FeCo exhibits excellent electromagnetic wave absorption properties with an optimal reflection loss value reaching up to − 73.47 dB at 13.75 GHz and a broad effective bandwidth (lower than − 10 dB) of 7.23 GHz (10.77 to 18 GHz) at a thickness of 2.4 mm. The synergistic effects of dielectric loss and magnetic loss mechanisms as well as excellent impedance matching characteristics and strong attenuation characteristics make AirRGO@FeCo hollow microspheres obtain high efficient microwave absorption capacity. Graphical abstract
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2022
·
IF 4.969
Ximing Zhang,Guiyang Xian,Jingyu Wang,Yang Fan,Yin Liu,Won-chun Oh,Zhenying Liu,Yueqin Wang,Ling Bing Kong
FeCo@C with a hollow porous dodecahedron structure was obtained through carbonization of ZIF-67 etched with Fe 3+ . During the pyrolysis process, the organic skeleton of the ZIF-67 was carbonized, forming graphitic carbon and carbon nanotubes. The etching effect of Fe 3+ with different concentrations on the morphology of ZIF-67 is studied. The MOF-derived porous carbon bimetallic nanocomposites exhibited stronger electromagnetic wave absorption performance than the monometallic ones. Specifically, the optimized sample has a reflection loss of −70.69 dB at 11.28 GHz, as the thickness is 2.07 mm. The enhanced electromagnetic wave (EMW) absorption performance of the nanocomposites can be attributed to the multiple interfaces and capacitive structure formed by catalytically produced carbon nanotubes. This achievement could be used as a reference for the development of MOF-derived porous carbon nanocomposite EMW absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
CARBON
·
2021
·
IF 9.594
Xiao Li,Caiyue Wen,Liting Yang,Ruixuan Zhang,Xiaohui Li,Yuesheng Li,Renchao Che
MXene , an emerging two-dimensional (2D) material, is widely used as a microwave absorber to defense the electromagnetic pollution in the high-frequency communication. However, how to reasonably reduce the excessive conductivity of the single-layer MXene itself remains a challenge. Herein, via vacuum-assisted filtration, a flexible MXene/FeCo film was prepared by the electrostatic interaction between negatively charged MXene and positively charged FeCo alloy. The continuous layered structure composed of single-layered MXene stacking was destroyed due to the intercalation of the magnetic nanoparticles , resulting in the reduced conductivity and proper impedance matching. Because of the anisotropy associated with different morphologies, the rough surface of nanoflower-like FeCo alloy has better interfacial polarization and magnetic loss capabilities that induced by the more active response sites, confirming by electron holography. The MXene-FeCo nanoflower-like film demonstrated better microwave absorption (MA) performance with the maximum RL value of −43.7 dB at 3.76 GHz, while the RL max reached −36.2 dB at 10.16 GHz of MXene-FeCo nanoplate-like film. Thus this effective frequency adjustment also expands the practical applications of absorbers to deal with different frequency of the outer microwave changes. It is expected that regulating morphology might shed new light on the absorbers designing with tunable MA performance.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 12
·期 3
·1617-1628
·
IF 11.9
Meng Ma,Wenqin Shao,Qindan Chu,Wenting Tao,Si Chen,Yanqin Shi,Huiwen He,Yulu Zhu,Xu Wang
With the strong support of the government for emerging technology industries, electromagnetic waves have brought convenience to people's lives, but also become an undeniable new source of pollution. Therefore, it is vital to develop new high-performance electromagnetic shielding materials. Herein, we designed a well-structured asymmetrical gradient multilayer composite film by constructing a controllable electromagnetic gradient. Using cellulose nanofibers as the matrix, a layer-by-layer filtration method was used to rationally distribute FeCo@rGO and MXene fillers to build an ordered multilayer structure that provides alternating conductive and magnetic gradients. Owing to gradient absorption shielding and reflection mechanisms for electromagnetic waves within the film layer, the EMI shielding efficiency (EMI SE) of the asymmetrical gradient alternating six-layer composite film reached 45.2 dB (X-band), and the reflection coefficient was reduced to 0.71 when 20 wt% filler was added. In addition, this composite film has good thermal conductivity and mechanical properties, exhibiting thermal conductivity of 2.90 W (m−1 K−1) and tensile strength of 26.2 MPa. This strategy provides a feasible approach for designing electromagnetic shielding composite materials with adjustable electromagnetic properties and has significant practical significance in expanding the application of MXene-based composite materials.
研究领域:
材料科学
·
电磁学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Kuankuan Wu,Zhangqi Liao,Yingli Zhu,Pingan Chen,Xiangcheng Li
Ferromagnetic metal/alloy particles are widely used in the field of electromagnetic wave absorption. Doping is an effective means of modulating the electromagnetic properties of magnetic metals and alloys. In this study, (Fe 3 Co 7 ) 1−x Ru x nanoparticles with different Ru doping contents are prepared using a polyvinylpyrrolidone (PVP)-assisted liquid-phase reduction process. First-principles calculations reveal that strong electron-orbit hybridization occurs between Ru-4 d and Fe/Co-3 d owing to the strong spin-orbit coupling effect of Ru-4 d orbital electrons. This generates a space charge distribution and carries a magnetic moment of 1.80 hbar/2. The use of Ru doping results in a reduction in FeCo alloy particle size from 1.5 µm to 200 nm, slight decrease in the saturation magnetization from 179 to 152 emu/g, and increase in the electrical conductivity from 2.79 × 10 -4 to 6.62 × 10 -4 S·cm -1 . The dielectric and magnetic loss values vary from 0.22 to 0.95 and 0.06–0.37, respectively, in the 2–18 GHz frequency range. Ru doping-induced dipole polarization relaxation, exchange resonance, and increased conductivity loss are the primary reasons for the enhanced electromagnetic loss of the material. When the level of Ru doping x reaches 0.10, the minimum reflection loss (RL min ) increases from − 21.5 to − 41.9 dB. Thus, (Fe 3 Co 7 ) 1−x Ru x is a promising material for electromagnetic loss due to its tunable composition, size, conductivity, magnetic properties , and excellent electromagnetic loss capability.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 10
·期 3
·1547-1559
·
IF 12.732
Ran Liu,Gaiping Du,Bin Liao,Weixin Xiao,Zhenguo An,Jingjie Zhang
Due to their multiple dissipation mechanisms, low density and easily tailored impedance matching, heterogeneous hollow structures are promising candidates for microwave absorbents towards wideband absorption and lightweight design. In this work, a new type of hollow microspheres with a porous carbon shell embedded with crystalline FeCo alloy nanoparticles have been prepared via a stepwise spray drying–calcination strategy. The effects of both the FeCo/C molar ratio and the calcination temperature on the structure and property of the porous hollow microspheres (PHMs) have been studied. It is found that the effective absorption bandwidth of the as-prepared FeCo/C PHMs surpassed 7.44 GHz at a matching thickness of 2.64 mm, which covers the full Ku-band. Moreover, with an elevated calcination temperature, high microwave absorbing performance can be achieved at a much reduced matching thickness. A probable absorbing mechanism has been proposed involving the synergistic effect of the hollow interior, the porous shell structure, and the electric and magnetic dissipation due to the coexistence of carbon and magnetic metals. This work opens a new pathway to synthesize microwave absorbents with a heterogeneous hollow structure, and may shed some light on the design and controlled preparation of other hollow structures with various shell compositions.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）