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1.
Jiahao Wang Lei Zhang Junfeng Yan Jiangni Yun Wu Zhao Kun Dai Huan Wang Yushan Sun 《Advanced functional materials》2024,34(37):2402419
MXene, a highly regarded material, has garnered significant attention within the electromagnetic wave (EMW) absorption field. However, the practical application of MXene is limited in harsh environments. Herein, a magic technique strategy of intercalation growth nucleation engineering is employed to prepare multifunctional MXene-based EMW absorption materials. By regularly introducing different metal ions between the layers of MXene, an ultrathin absorber can be achieved by annealing after reacting in specific positions. The synthesized MCFC-69-8 shows hydrophobicity properties and exhibits a large charge-transfer resistance of 18112 Ω cm2 with a low corrosion rate and corrosion rate, indicating a good anti-corrosion property. Through applying a series of mathematical methods, MCFC-69-8 shows 25% relaxation polarization loss and 75% conduction loss, and its relaxation time is linked with the specific type of relaxation polarization loss, resulting in an effective absorption bandwidth (EAB) of 4.9 GHz with an ultra-thin optimal matching thickness of 1.48 mm. Finally, an absorber is built using CST to attain an ultrabroad EAB covering 2–18 GHz. This engineering not only simplifies the intercalation process but also achieves a high-performance and anti-corrosion EMW absorber, providing a valuable perception for realizing thinner MXene-based EMW absorbers in the future. 相似文献
2.
Ruiwen Shu Gengyuan Zhang Chao Zhang Yue Wu Jiabin Zhang 《Advanced Electronic Materials》2021,7(2):2001001
Heteroatom nitrogen doping is considered an effective strategy to enhance the electromagnetic wave (EMW) absorption capacity of reduced graphene oxide (RGO). Herein, nitrogen-doped RGO aerogels (NGAs) are synthesized via hydrothermal self-assembly followed by lyophilization processes. Results of micromorphology analysis show that the as-prepared NGAs display unique 3D porous and netlike structure. Moreover, the effects of nitrogen doping and filler contents on EMW absorption properties of NGAs are studied. The as-synthesized NGA with nitrogen content of 9.41 at% and a bulk density of 8.7 mg cm–3 presents the integrated optimal EMW absorption performance. Specifically, the minimum reflection loss of –56.4 dB is achieved and maximum absorption bandwidth of 6.8 GHz is reached, covering the whole Ku band. In addition, the possible EMW absorption mechanisms of obtained NGAs are proposed. Therefore, the as-synthesized NGAs can be exploited as promising high-efficiency and lightweight EMW absorbers. 相似文献
3.
Rational manipulation of multimetal hybrid materials (HMs) with tunable substitution or phases is evolving as an effective strategy to meet the controllable electromagnetic (EM) properties and EM wave (EMW) absorption. Herein, a new thermodynamic and kinetic cocontrol strategy is proposed to construct Zn/Co bimetal HMs with tuning ion and phase hybridization for synergistic effect on EM properties for the first time. Auxiliary chelating agent triethanolamine (TEA) dominates the phase separation by stepwise Zn/Co deposition in metal–organic frameworks, then the pyrolysis process under gradient temperature give rise to controllable ion hybridization products due to thermal motion. Benefiting from the tunable collaboration between defects polarization and interfacial polarization, the 700 °C HMs exhibit ultrahigh EM parameters and EMW absorption, of which products with no TEA deliver the effective absorbing bandwidth of 4.80 GHz (1.6 mm) and minimum reflection loss of −45.85 dB. The results indicated that synergistic effect of ion and phase hybridization can improve the defects induced “polarization centers” and coherent interfaces induced interfacial polarization. Furthermore, the comprehensive research and deep understanding on respective contribution of hybridization forms provide a precise inspiration in developing bimetal and even multimetal ferrite with tunable hybridization structure. 相似文献
4.
Baojun Wang Wei Wei Fangzhi Huang Fenghua Liu Shikuo Li Hui Zhang 《Advanced functional materials》2024,34(45):2404484
Manipulating the electronic structure and geometric coordination environment of single metal atoms has been considered as promising approach for enhancing dipole polarization and enriching electromagnetic attenuation mechanisms. However, achieving precise control of the dielectric polarization response at atomic scale remains a huge challenge. Herein, a metal-acetate coordination complexes-assisted strategy is proposed to prepare spatially isolated cobalt (Co) atoms embedded in accordion-like nitrogen-doped carbon (NC) matrix. The interactions between metal atoms and NC matrix are carefully tailored through the successive evolution of dispersion states of Co species, ranging from individual atoms to atomic clusters to nanoparticles. Density functional theory reveals that the orbital hybridization between the d electrons of embedded Co atoms and p electrons of coordinated N atoms induces the electron redistribution at N sites, enabling enhanced electric dipole polarization and robust room temperature magnetism (a saturation magnetization of 0.108 emu g−1 at 300 K). Consequently, Co-SAs@NC exhibits optimal electromagnetic wave absorption properties with a minimum reflection loss of -54.4 dB and an effective absorption bandwidth of 8.4 GHz. This work demonstrates an efficient strategy for modulating electromagnetic response at atomic level and provides a novel insight into the d/p electrons orbital hybridization between single metal atoms and NC species. 相似文献
5.
Ji Liu Zhangshuo Liu Hao‐Bin Zhang Wei Chen Zhenfang Zhao Qi‐Wei Wang Zhong‐Zhen Yu 《Advanced Electronic Materials》2020,6(1)
Ultrathin and flexible electromagnetic interference (EMI) shielding materials are urgently required to shield increasingly serious radiation pollution. Newly emerged 2‐dimensional transition‐metal carbides (MXenes) are promising for efficient EMI shielding due to their superb electrical conductivity, versatile surface chemistry, and layered structure. However, the mechanical performance of MXene films is not satisfactory for engineering applications, and the traditional reinforcement approaches usually cause serious reduction in electrical conductivity of the films. An efficient strategy is demonstrated to reinforce MXene films with graphene oxide, leading to enhanced interfacial interactions and more densely packed layered structures. The modified MXene film exhibits a high tensile strength of 209 MPa while maintaining its high electrical conductivity close to that of pristine MXene film. An outstanding shielding effectiveness of 50.2 dB is achieved at a small film thickness of 7 µm. Moreover, a facile technique is used to tune the wetting behavior of the modified MXene films. The water contact angle can be readily regulated from 65.7° to 95.7°. This film, with excellent EMI shielding performance and tunable wetting behavior, is highly promising for various applications in aerospace, flexible supercapacitors, and smart electronics. 相似文献
6.
Zonglin Liu Xu Zhao Fuhua Xue Liangliang Xu He Chen Zhong Chen Qian Yan Jinhua Xiong Haowen Zheng Pengyang Li Huanxin Lian Yunxiang Chen Qingyu Peng Xiaodong He 《Advanced functional materials》2024,34(49):2409069
MXenes, a burgeoning family of 2D materials with high conductivity and large specific surface area, are ideal electromagnetic absorbing materials. However, the ample polar functional groups lead to poor dispersion in the non-polar matrix, limiting its application in non-polar-polymer-based composites. With the help of the shear rheological properties of SiO2, the conflict is resolved here by directly dispersing MXene aqueous dispersion into the non-polar resin. Water is locked dynamically through SiO2 nanoparticles among the MXene@SiO2 nanosheets, suppressing MXene's self-restacking and aggregation in the resin matrix. Therefore, the fabrication of uniform MXene/non-polar polymer composites is achieved. Meanwhile, this method allows different nanoparticles (Fe3O4, etc.) to be evenly dispersed among the MXene nanosheets to further improve the composites' electromagnetic parameters. The as-prepared composites achieve remarkable absorbing performance with a low MXene concentration (≤5 wt.‰). The SMEP-h achieves the maximum reflection loss value of over 60 dB at 12 GHz (at the thickness of 2.15 mm), and the SMEP-F possesses a broad effective absorbing bandwidth of over 6.18 GHz (at the thickness of 1.75 mm). The shear-rheological-assisted MXene dispersion method in the non-polar matrix paves an avenue for the design of outstanding MXene-based electromagnetic absorbing composites. 相似文献
7.
Yan Cheng Huanqin Zhao Hualiang Lv Tengfei Shi Guangbin Ji Yanglong Hou 《Advanced Electronic Materials》2020,6(1)
Currently, a versatile route is urgently required to achieve excellent electromagnetic wave (EMW) absorption and shielding functions simultaneously. A lightweight, flexible and sustainable 3D framework aerogel is designed to reach this goal, which is assembled by unique “1D‐1D” combination, nanoscale carbon nanotubes (CNTs) grown on microscale carbon fiber. EM absorption requires appropriate conductivity of filler to acquire moderate permittivity. On the contrary, EM shielding requires great conductivity to reflect most of the incident EMW. Based on this design concept, the change of electric conductivity of as‐obtained samples through in situ regulation of the growth state of CNTs is successfully controlled. When the CNTs are short and curly, the optimized conductivity favors excellent microwave absorption with wide absorption bandwidth of 5.08 GHz at only 1.6 mm. When the CNTs are long and straight, the increased conductivity is clearly boosted with 29.8 dB EM shielding effectiveness. This elaborate architecture and controlled CNT growth allow the designed 3D framework aerogel to be applied in both EM wave absorption and shielding. This conductivity tunable route gives inspiration for fabricating other efficient EM absorption and shielding devices. 相似文献
8.
本文考虑材料的磁性,利用电磁场的边值关系研究磁导率对菲涅尔公式的修正。文中利用所定义的介质界面矢量将电磁场量正交分解,统一处理垂直和平行于入射面的场分量关系,提供推导菲涅尔公式的另外方法,并对结果进行深入讨论。结果表明,材料磁性对菲涅尔公式的修正可以由两种材料的相对磁导率之比描述。 相似文献
9.
10.
Jiawei Ding Rongrong Shi Chuangchuang Gong Chenxu Wang Yue Guo Tong Chen Yijing Zhang Hongwei Cong Chunsheng Shi Fang He 《Advanced functional materials》2023,33(48):2305463
To tackle the increasingly complex electromagnetic (EM) pollution environment, the application-oriented electromagnetic wave (EMW) absorption materials with ultra-thin, light weight and strong tolerance to harsh environment are urgently explored. Although graphene aerogel-based lightweight EMW absorbers have been developed, thinner thickness and more effective polarization loss strategies are still essential. Based on the theory of EMW transmission, this work innovatively proposes a high attenuation design strategy for obtaining ultra-thin EMW absorption materials, cobalt selenide (CoSe2) is determined as animportant part of ultra-thin absorbers. In order to obtain a dielectric parameter range that satisfies the ultra-thin absorption characteristics and improve the lightweight properties of EMW absorption materials, a composite of CoSe2 modified N-doped reduced graphene oxide (N-RGO/CoSe2) is designed. Meanwhile, the controllable introduction of defect engineering into RGO can activate Schottky heterointerfaces of composites to generate a strong interfacial polarization effect, achieving ultra-thin characteristics while significantly improving the EM loss capability. In addition, infrared thermal images and anti-icing experiments show that the composite has good corrosion resistance, infrared stealth, and thermal insulation properties. Therefore, this work provides an effective strategy for obtaining thin-thickness, light-weight, and high-performance EMW absorption materials, embodying the advantages of N-RGO/CoSe2 composites in practical applications. 相似文献
11.
2D materials and their composites with electromagnetic properties are becoming increasingly popular. Obtaining insight into the nature of electromagnetic (EM) response manipulation is imperative to guide scientific research and technological exploitation at such a critical time. From this perspective, the dielectric genes of 2D material hybrids have been highlighted based on the recent literature. This endows an unlimited possibility of manipulating the EM response, even at elevated temperatures. The definitions and criteria of dielectric genes toward 2D material hybrids and composites are systematically clarified and summarized. The dielectric gene categories are successfully discriminated, including the conduction networks, intrinsic defects, impurity defects, and interfaces in the composite, and their temperature evolution is revealed in detail. More importantly, tuning strategies for microwave absorption, electromagnetic shielding effectiveness, and expanded electromagnetic functions are thoroughly discussed. Finally, significant predictions are provided for multispectral electromagnetic functions, and future applications of multifunctional exploration are anticipated. Dielectric genes will open an unexpected horizon for advanced functional materials in the coming 5G/6G age, providing a significant boost to promoting environmental electromagnetic protection, electromagnetic devices, and next-generation smart devices. 相似文献
12.
Xue Yang Qian Wang Kai Zhu Ke Ye Guiling Wang Dianxue Cao Jun Yan 《Advanced functional materials》2021,31(20):2101087
2D MXene materials have attracted intensive attention in energy storage application. However, MXene usually undergoes serious face-to-face restacking and inferior stability, significantly preventing its further commercial application. Herein, to suppress the oxidation and self-restacking of MXene, an efficient and fast self-assembly route to prepare a 3D porous oxidation-resistant MXene/graphene (PMG) composite with the assistance of an in situ sacrificial metallic zinc template is demonstrated. The self-assembled 3D porous architecture can effectively prevent the oxidation of MXene layers with no evident variation in electrical conductivity in air at room temperature after two months, guaranteeing outstanding electrical conductivity and abundant electrochemical active sites accessible to electrolyte ions. Consequently, the PMG-5 electrode possesses a striking specific capacitance of 393 F g−1, superb rate performance (32.7% at 10 V s−1), and outstanding cycling stability. Furthermore, the as-assembled asymmetric supercapacitor possesses a pronounced energy density of 50.8 Wh kg−1 and remarkable cycling stability with a 4.3% deterioration of specific capacitance after 10 000 cycles. This work paves a new avenue to solve the two long-standing significant challenges of MXene in the future. 相似文献
13.
Meng Zhu Yang Yue Yongfa Cheng Yanan Zhang Jun Su Fei Long Xueliang Jiang Yanan Ma Yihua Gao 《Advanced Electronic Materials》2020,6(2)
Pressure sensing is key to smart wearable electronics and human–machine interaction interfaces. To achieve a high‐performance pressure sensor that has broad linear range and is capable of detecting subtle changes of pressure, the good choice of sensing materials and rational design of structures are both needed. A novel piezoresistive sensor based on hollow MXene spheres/reduced graphene composite aerogel and flexible interdigital electrodes is presented. Benefiting from the unique microstructure of the composite aerogel, the prepared pressure sensor exhibits high sensitivity (609 kPa−1 in the range of 6.4–10 kPa), broad linear range (0–10 kPa), low detection limit (6 Pa), short response time (232 ms), and good durability (6000 cycles). Moreover, the device is able to monitor various human activities in real time, as well as distinguish tiny differences of grain. The potential application of mapping the location and intensity of the pressures is also explored. 相似文献
14.
The development of multicomponent dielectric composites has become a mainstream approach for obtaining excellent electromagnetic wave (EMW) absorbers. However, conventional component introduction is often performed blindly and based only on semiempirical rules, lacking precise modulation of components, interfaces, and defects during the reaction process. Herein, a competitive reaction mechanism is proposed for the first time, in which not only the metal ion concentration but also its characteristic are two feasible parameters to control the components, interfaces, and defects to tailor the EMW absorption performances of Cu-based binary metal sulfides. The appropriate heterogeneous interfaces and components and the abundant defects can synergistically benefit the EMW absorption capacity by forming perfect impedance matching and multiple dielectric polarizations. As a result, combined with these advantages, an effective absorption band) of 6.80 GHz (6.3–13.1 GHz) is achieved at 2.80 mm for Cu–Co binary metal sulfide, showing the sole middle-frequency broadband absorption of reported sulfide-based absorbers to date. Other Cu-based binary metal sulfides deliver different EMW absorption behaviors. This work breaks through the limitation of traditional component design, opening up a novel methodology for designing multicomponent composites beyond sulfides with broadband absorption. 相似文献
15.
Chunyang Xu Kaicheng Luo Yiqian Du Huibin Zhang Xiaowei Lv Hualiang Lv Ruixuan Zhang Chang Zhang Jincang Zhang Renchao Che 《Advanced functional materials》2023,33(47):2307529
The fabrication of nanometer-sized magnetic heterostructures with controlled magnetic components and specific interfaces holds great significance in the field of electromagnetic (EM) wave absorption. However, the process of achieving these structures still poses significant challenges. Here, abundant magnetic heterostructures are successfully fabricated by utilizing the surface energy anisotropy differences of the nonasymmetric hammer-shaped interface to support the nucleation and growth of magnetic heterostructure components while effectively inhibiting their aggregation. Through a confined growth strategy via in situ growth of FeOOH and sequentially precise thermal treatments, dispersion of the heterostructures is achieved at the nanometer scale, while also observing a high degree of chemical stability due to occurrence of a charge-compensation effect at the interface. Consequently, a series of magnetic heterostructures are obtained via phase translations of FeOOH precursors. The nanometer-sized heterostructures demonstrate multilevel interfacial polarization effects. Furthermore, the hierarchical core–shell structure of the heterostructures promotes anisotropic polarization absorption. As a result, the multiple interfaces and nanometer-sized Fe/Fe3O4@SiO2@Fe-2 heterostructures demonstrate improved EM wave attenuation performance. Remarkably, they achieve an absorption bandwidth of 9 GHz at a thickness of 1.8 mm. A novel avenue is introduced here for investigating the intricate relationship between structure and properties in magnetic heterostructures. 相似文献
16.
为精确计算太赫兹波大气传输吸收衰减,需建立太赫兹波传播路径模型,而后获取沿传播路径的相关变化大气参量,并通过国际电联(ITU)标准计算分段的吸收衰减值,最终进行累加计算得出总的大气衰减量值。受限于气象观测设备及手段,沿传播路径完整的大气参量难以获取。由于地球重力场产生的大气折射效应,电磁波在大气层中传播时其路径呈现曲线弯曲传播。基于区域大气再分析资料集基础数据转化的太赫兹波大气传输衰减精确计算方法,通过ITU标准这个桥梁,在气象数据和大气传输衰减间建立关联关系,最终运用在飞行器太赫兹波地面探测类工程技术上,以预估太赫兹波通信链路的大气吸收衰减值。 相似文献
17.
Jun Yan Chang E. Ren Kathleen Maleski Christine B. Hatter Babak Anasori Patrick Urbankowski Asya Sarycheva Yury Gogotsi 《Advanced functional materials》2017,27(30)
A strategy to prepare flexible and conductive MXene/graphene (reduced graphene oxide, rGO) supercapacitor electrodes by using electrostatic self‐assembly between positively charged rGO modified with poly(diallyldimethylammonium chloride) and negatively charged titanium carbide MXene nanosheets is presented. After electrostatic assembly, rGO nanosheets are inserted in‐between MXene layers. As a result, the self‐restacking of MXene nanosheets is effectively prevented, leading to a considerably increased interlayer spacing. Accelerated diffusion of electrolyte ions enables more electroactive sites to become accessible. The freestanding MXene/rGO‐5 wt% electrode displays a volumetric capacitance of 1040 F cm?3 at a scan rate of 2 mV s?1 , an impressive rate capability with 61% capacitance retention at 1 V s?1 and long cycle life. Moreover, the fabricated binder‐free symmetric supercapacitor shows an ultrahigh volumetric energy density of 32.6 Wh L?1, which is among the highest values reported for carbon and MXene based materials in aqueous electrolytes. This work provides fundamental insight into the effect of interlayer spacing on the electrochemical performance of 2D hybrid materials and sheds light on the design of next‐generation flexible, portable and highly integrated supercapacitors with high volumetric and rate performances. 相似文献
18.
羰基铁粉作为常见的电磁波吸收涂料,其形貌和含量对电磁波吸收性能有极大影响。为掌握羰基铁粉吸波涂料的介电常数、磁导率等参数随频率的变化规律,制备并测试了不同配比的微米级片状羰基铁粉同轴环样品。测试结果表明:羰基铁粉的最佳质量分数为60%~80%,样品厚度为2 mm、2.5 mm时,反射损耗-10 dB以下的有效吸收频宽分别为7.36 GHz、2.4 GHz,最大反射损耗值分别为-19.612 dB、-27.707 dB。样品厚度增加,最大吸收频率移向低频端。 相似文献
19.
Yajie Liu Xin Sun Zhiming Song Xiaofang Liu Ronghai Yu 《Advanced Electronic Materials》2021,7(3):2000970
Soft magnetic micro/nanostructures are highly desirable for pursuing excellent magnetic properties and electromagnetic wave (EMW) absorption performance. However, their magnetic loss at high frequency is usually very low due to the sharp drop of permeability, and thus results in a heavy loading in matrix and a large layer thickness, which are not conductive to the development of ultralight and ultrathin EMW absorbers. Here, an ultralight and ultrathin EMW absorber based on a parallel Ni wire array are reported, and an orientation-enhanced strategy to improve EMW absorption performance is proposed. Combining with the finite element simulation, it is found that the parallel orientation of Ni wires with a capacitor-like structure enhances the interfacial polarization, thereby improving dielectric loss. The strong shape anisotropy caused by orientation increases magnetic loss by enhancing magnetic resonances, which further improves impedance matching. The parallel Ni wire array exhibits excellent EMW absorption and achieves the largest specific reflection loss (reflection loss/(thickness × loading)) among magnetic wire-based absorbers. 相似文献
20.
Hu Liu Xueqian Li Xiaoying Zhao Min Zhang Xinhua Liu Shichun Yang Hongjing Wu Zhenhui Ma 《Advanced functional materials》2023,33(40):2304442
It is very challenging to demonstrate the intrinsic feature and absorption mechanism for electromagnetic (EM) wave absorber since dipole polarization loss is always discussed together with magnetic loss, conductive loss, defects/interfacial polarization, and so on. To address this issue, here, a kind of atomic composites is reported, including single-atom Co and Co cluster with controllable atom dipole to tune the polarization and establish the link between dipole polarization and the EM wave absorption. Using a chemical synthesis route, the atomic composites are fabricated, including Co single-atom (SA) sites and cluster (Cs) on nitrogen-doped graphitic carbon (Co1+Cs/NGC). Due to the special design, the effect of magnetic loss, conductive loss, and interfacial polarization on EM wave dissipation can be ignored so that it can only highlight dielectric loss caused by dipole polarization. And, by controlling the Co atoms concentration, it can tune the valence state of Co atoms between 0 to +2 to control dipole polarization and relaxation. As a result, the Co1+Cs/NGC-2 with Co concentration of 6.0 wt% exhibits optimized dipole moments and thus excellent absorption performance (the reflection loss exceeds −54.3 dB, and the effective absorption bandwidth with RL ≤−10 dB reaches 7.0 GHz at 2.0 mm) due to the effective dipole polarization caused by the large annular dipole bounded between Co SA sites and Co Cs. This study proposes a simplified model to clarify EM wave absorption mechanism from atom view. 相似文献