Nanoscale
·
2022
·Vol. 14
·期 29
·10375-10388
·
IF 8.307
Congyu Zhou,Zhengjun Yao,Bo Wei,Wenying Li,Zhejia Li,Xuewei Tao,Jintang Zhou
The increasing hazard of electromagnetic radiation prompts people to pursue absorbing materials with better performance. However, absorbing materials with a single loss mechanism usually is unable to obtain better absorbing performance due to low impedance matching or high filling ratio. Therefore, this work proposes a C/NiCo2S4 (CNCS) material with both dielectric loss/magnetic loss to achieve efficient absorption of electromagnetic waves. The simple preparation of CNCS materials was achieved through the etching of the ZIF-67 template by nickel nitrate and the subsequent hydrothermal vulcanization process. Its unique prismatic dodecahedron hollow structure promotes multiple scattering of electromagnetic waves. The attachment of the magnetic NiCo2S4 particles on the surface of the carbon template further promotes the interface polarization and dipole polarization, which is equivalent to the formation of a resistance-rich microcircuit and enhances the effect of the conductance loss on electromagnetic waves. At 2–18 GHz, the CNCS-2 with 30% paraffin addition achieves an effective bandwidth of 5.54 GHz at a matching thickness of 1.7 mm, and has a maximum reflection loss of −36.44 dB at 1.5 mm. By adjusting the thickness of the material matching layer (1–3 mm), an effective bandwidth of up to 13.48 GHz can be achieved, perfectly covering the X-band and Ku-band. Based on the simple preparation process of the material, the special hollow structure and the multiple loss mechanisms for electromagnetic waves, we believe that CNCS can become a strong competitor for high-efficiency broadband absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Jing Ouyang,Zilong He,Yi Zhang,Huaming Yang,Qihang Zhao
Organic ligands and metal ions in the metal–organic frameworks (MOFs, a type of porous magnetic metal/carbon nanocomposites obtained through high-temperature carbonization) have caused widespread concerns in the field of microwave absorption because of the existence of various microwave loss mechanisms in these materials. However, MOF-driven microwave absorbing materials with high absorption intensity and wide absorption band still require further research and development. In this work, hollow sphere trimetallic FeCoNi@C microwave absorbing materials via high-temperature carbonization were obtained using FeCoNi-based MOF-74 (FeCoNi-MOF) as the precursor. The effects of different carbonization conditions on the microwave absorption properties of the materials were studied. FeCoNi-MOF-74 annealed at 700 °C showed superior microwave absorption capacity, where the RL value reached −64.75 dB at 15.44 GHz corresponding to the actual application thickness of the absorber (only 2.1 mm), and the minimum RL values reached −69.03 dB at 5.52 GHz. Furthermore, the as-prepared sample can fully cover the Ku band and X band at only 2.1 and 3.1 mm, respectively. The maximum EAB reached 8.08 GHz (9.92–18 GHz) when the thickness of the absorber was 2.47 mm. Such remarkable absorption performance is attributed to the synergetic effects between the multiple loss mechanisms of the FeCoNi@C, and the improved impedance matching characteristic came from the hollow sphere morphology.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Xueyun Han,Siyu Zhang,Lei Qiao,Peidong Peng,Chenghao Fu,Ke Liu,Zhongjun Ma
Metal–organic framework (MOF)-derived materials have gained popularity as microwave absorbing materials due to their electromagnetic dissipation advantages. In this study, a special type of MOF (ZIF-L) was used as a precursor; tannic acid was introduced for chemical etching. The resulting material obtained by in situ carbonization was a hollow structure of N-doped carbon embedded by Co nanoparticles (CoHNC), which retained the original pumpkin seed shape but had a hierarchical porous structure on the inside. By adjustment of the amount of cobalt nitrate and the carbonation temperature, the electromagnetic parameters could be altered, improving impedance matching and enabling different microwave absorption properties to be obtained. At 16.96 GHz, the material exhibits an optimal reflection loss of −45.5 dB, an effective bandwidth of 3.04 GHz, and a matching thickness of only 1.4 mm with a material filler of 30 wt %. The microwave loss mechanism is formed by the dual loss mechanism with dielectric loss as the main loss and magnetic loss as the auxiliary one. Therefore, the synthesis of the CoHNC composite through simple etching provides a useful idea for optimizing microwave absorbing 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
ACS Applied Nano Materials
·
2025
·
IF 5.5
Shiqi Li,Qingfeng Zhang,Yixuan Zhang,Shengyong Mo,Xuezhen Qi,Yurong Cai
Loss capacity and impedance matching are critical factors that govern the electromagnetic wave-absorption performance of materials. However, achieving an optimal synergistic balance between these two factors remains a significant challenge. In this study, we fabricate an ultralight and anisotropic aerogel synthesized using directional freeze-drying with bacterial cellulose and MXene as the structural framework. Subsequently, MoS2 nanosheets were uniformly deposited onto the aerogel via an in situ hydrothermal process, forming nanoarrays that enhance multiple scattering and interfacial polarization. The aerogel demonstrates an ultralow reflection loss of −53.6 dB (2.26 mm thickness) and an ultrawide absorption bandwidth of 8.16 GHz (2.66 mm thickness). The oriented porous architecture and multiphase composition of the bacterial cellulose/MXene aerogel synergistically enhance performance through multiscale loss mechanisms (e.g., conductive loss and polarization loss) and adjustable impedance matching. Furthermore, the aerogel demonstrated excellent thermal insulation. This work provides valuable insights into the rational design of electromagnetic wave-absorbing materials with enhanced adaptability for diverse application scenarios.
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 FUNCTIONAL MATERIALS
·
2022
·Vol. 32
·期 34
·2204499
·
IF 19.924
Yue Liu,Xinfeng Zhou,Zirui Jia,Hongjing Wu,Guanglei Wu
Polymeric metal-organic framework (MOF)-derived composites are promising functional materials because of their exceptional chemical homogeneity, designable components, and adjustable pore size. The modulation of oxygen and Mn vacancies via the introduction of heteroatoms and changes in the annealing temperature in MOFs-derived composites can be a possible solution to investigate the polarization loss mechanism, which facilitates the improvement of electromagnetic loss capacity. Herein, the design of laminate-stacked sphere-shaped trimetallic CoNiMn-MOFs is presented. The derived CoNi/MnO@C composites retain the original topography of the MOFs. The concentration of oxygen vacancies increases with the incorporation of heteroatoms, but decreases with annealing temperature, which prevails in the polarization loss mechanism rather than the contribution of Mn 2+ vacancies and heterogeneous interfaces. Therefore, the minimum reflection loss of the CoNi/MnO@C sample demonstrates −55.2 dB at 2.6 mm and the broad effective absorption bandwidth reaches 8.0 GHz at 2.1 mm. This work is expected to provide meaningful insights into the significant effect of ion vacancy modulation on the EM wave-absorbing performance of Mn-based MOFs-derived composites.
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 Composites and Hybrid Materials
·
2024
·Vol. 7
·期 3
·1-15
·
IF 23.2
Xiang Yao,Qiu Jiahang,Elsharkawy Eman Ramadan,Melhi Saad,Zhang Mu,Luo Zhengtang,Zhao Rongzhi,Sun Xudong
The pursuit of achieving wideband electromagnetic wave absorption to meet the demands in multiple fields has attracted attention in the field of electromagnetic wave absorption. Considering that the dipole moments of different scales can correspond to different polarization bands, the coupling of multi-scale loss mechanisms may help to realize the electromagnetic wave absorption in the wide band. Therefore, we fabricated N-doped Co/C composites derived from ZIF-67 through a facile wet chemistry approach and pyrolysis process. Due to the precise fabrication method and the design of the Stranski-Krastanow growth mode, the prepared N-doped Co/C composites contain abundant functional groups, magnetic particles, and cobalt quantum dots. By combining atomic-scale doping loss and mesoscopic-scale hollow structures, the Co/C composite materials achieve the coupling of multiple-scale loss mechanisms and demonstrate outstanding electromagnetic wave absorption performance: the minimum reflection loss (RL min ) value reaches −57.0 dB at 17.9 GHz when the thickness is 1.73 mm, and the effective absorption bandwidth (EABD) reaches the maximum value of 5.7 GHz when the thickness is 2 mm. To sum up, this work provides a new strategy for realizing the broadband absorption of further electromagnetic wave absorption 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
ACS Applied Electronic Materials
·
2019
·
IF 0
Ting Huang,Zhengchen Wu,Jiawei Lin,Qi Yu,Donggui Tan,Lei Li
The hierarchically porous Co/C foam with low density has been successfully prepared by a facile sequential process of foaming–lyophilization–carbonization. In the hierarchical structure, the macro- and mesoscopic pores are created by surfactant-assisted foaming and lyophilization processes, while the nanoscale pores spring from the etching reaction between gelatin-derived carbon and metal oxides during the high-temperature carbonization. By adjustment of the carbonization temperature and loading of the as-prepared absorbent, a maximum reflection loss (RL) achieves −56.5 dB at the thickness of 2.49 mm, and a broad effective absorption bandwidth (EAB) of 6.0 GHz is reached. The corresponding mechanism demonstrates that such an outstanding performance is rooted in the synergetic loss capacities from dielectric and magnetic components. Therefore, it is believed that this work provides a significant guidance for exploring high-performance and lightweight microwave absorbents.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
Small
·
2023
·Vol. 19
·期 27
·2300257
·
IF 13.3
Fangyu Gan,Qingrong Rao,Jianqiu Deng,Lichun Cheng,Yan Zhong,Zhao Lu,Feng Wang,Jiang Wang,Huaiying Zhou,Guanghui Rao
The optimization design of micro-structure and composition is an important strategy to obtain high-performance metal-based electromagnetic (EM) wave absorption materials. In this work, ZnO/FeNi composites derived from ZnFeNi layered double hydroxides are prepared by a one-step hydrothermal method and subsequent pyrolysis process, and can be employed as an effective alternative for high-performance EM wave absorber. A series of ZnO/FeNi composites with different structures are obtained by varying the molar ratios of Zn 2+ /Fe 3+ /Ni 2+ , and the ZnO/FeNi composites with a Zn 2+ /Fe 3+ /Ni 2+ molar ratio of 6:1:3 show a hierarchical flower-like structure. Owing to the strong synergistic loss mechanism of dielectric-magnetic components and favorable structural features, this hierarchical flower-like ZnO/FeNi sample supplies the optimal EM wave absorption performance with the highest reflection loss of −52.08 dB and the widest effective absorption bandwidth of 6.56 GHz. The EM simulation further demonstrates that impedance matching plays a determining role in EM wave absorption performance. This work provides a new way for the fabrication of a high-performance metal-based EM wave absorber.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2020
·
IF 4.217
Zhongji Qu,Yu Wang,Wei Wang,Dan Yu
With the increasing demand for microwave absorbing materials, to develop a microwave absorber with a simple synthesis process is of great significance to the field of protection. Herein we have successfully loaded iron-cobalt-nickel oxide (FeCoNiO x ) onto the as-prepared polydopamine-reduced graphene oxide (PDA-rGO) through a two-step process. The preparation method has mild reaction conditions without high temperature and pressure compared with the traditional method, which is conducive to large-scale production. Based on effectively combining dielectric loss and magnetic loss mechanism, the obtained material possesses excellent electromagnetic waves absorbing performance with the minimum RL value of −36.28 dB. The results proved that the composites can be endowed with various microwave absorption effects by the adjustion of different component ratios. In addition, the microwave absorption mechanism was dicussed in detail, and we believe that the results of our research have certain guiding significance for preparation of efficient microwave absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITE STRUCTURES
·
2021
·
IF 5.407
Wentong Yang,Xiaoming Qi,Jiawen Sun,Laiming Yu,Yubing Dong,Yaqin Fu,Yaofeng Zhu
In this work, a novel deformable honeycomb sandwich composite felt (DCF) was fabricated through dipping method that using polyester felt (PET-F) as matrix, water-borne epoxy resin mixed with self-made microwave absorbent as microwave absorbing coating. The DCF with honeycomb-like sandwich structure possesses enhanced mechanical properties and excellent microwave absorption (MA) performance. In addition, the components of coating also endow DCF with shape memory behavior which makes it more suitable for various scenarios. The minimum reflection loss of the DCF with the optimal comprehensive performance can reach −55.90 dB with the thickness of only 1.4 mm and the effective absorption bandwidth is 4.87 GHz. The excellent MA performance of DCF is attributed to the well impedance matching and strong loss characteristics, which is closely related to moderate conductive network, multiple loss mechanism and special structural. This work may have reference significance for the practical application of MA materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Jixing Chai,Junye Cheng,Deqing Zhang,Yingfei Xiong,Xiuying Yang,Xuewei Ba,Sana Ullah,Guangping Zheng,Ming Yan,Maosheng Cao
The 2D molybdenum disulfide nanosheets (MoS 2 -NS) has exhibited great potential in electromagnetic wave absorbing (EMA) due to larger surface area and peculiar electronic properties. However, due to the poor impedance matching and limited electromagnetic loss capability of pure MoS 2 -NS, its practical applications are significantly challenging. Herein, we firstly implanted Co 3 O 4 nanoparticles (Co 3 O 4 -NPS) on MoS 2 -NS by a facile hydrothermal method to improve the EMA performance. The resulting MoS 2 /Co 3 O 4 hybrids exhibit the minimum reflection loss (RL) value of −43.56 dB at 6.96 GHz with 20 wt% Co 3 O 4 loading under the samples thickness of 4.0 mm. The widest bandwidth with the RL value less than −10 dB of MoS 2 /Co 3 O 4 hybrids was determined to be 4.76 GHz (13.24 to 18 GHz) under the absorber thickness of 2.0 mm. The excellent performance is ascribed to that implanted Co 3 O 4 -NPS on MoS 2 -NS could turn tuning impedance matching and improving synergetic magnetic loss and dielectric loss. Herein, this work not only presents a facile strategy of achieving high-performance MoS 2 -based EMA materials, but also provides important implications for designing the other EMA 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
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Bo Wei,Congyu Zhou,Zhengjun Yao,Linling Xu,Zhejia Li,Li Wan,Jinsen Hou,Jintang Zhou
Due to the excessively high electrical conductivity and single dielectric properties of the graphene material, when used as a wave absorbing material, the imbalance of impedance matching causes strong reflection effects, resulting in poor wave absorbing performance. In this research, we partially reduced graphene oxide (GO) and loaded magnetic quantum dots (MQDs) through a one-step pyrolysis method, and a novel composite material of three MQDs (Fe, Fe 3 O 4 , Fe 3 C) embedded partially reduced graphene oxide (P-rGO) was prepared and the influence of pyrolysis temperature on its electromagnetic performance was systematically studied. The research found that ethylene glycol selectively reduced the C O functional group of the GO component and enhanced its dielectric properties; the loading of MQDs for a single carbon material increased the magnetic loss mechanism and improved the impedance matching and attenuation capabilities. In addition, the flaky structure of GO and the ultra-small nanostructure of MQDs suppress the eddy current effect and promote the occurrence of exchange resonance between magnetic particles. The prepared four sets of samples exhibit excellent absorbing properties in the 2–18 GHz frequency band. Among them, the samples prepared by pyrolysis at 800 °C can obtain 5.59 GHz broadband electromagnetic wave absorption at an ultra-thin thickness of 1.7 mm. The special quantum size effect and enhanced electromagnetic wave attenuation capabilities are the main reasons for the high-efficiency microwave absorption of MQDs/P-rGO 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
危险品化学品经营许可证（带存储）