Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is con...Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is considered an effective means to achieve high-efficiency EMW absorption.However,interface modulation engineering has not been fully discussed and has great potential in the field of EMW absorption.In this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal reduction.By utilizing the different properties of different substances,rich heterogeneous interfaces are constructed.This effectively promotes charge transfer and enhances interfacial polarization and conduction loss.The prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy resin.The minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 GHz.Moreover,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel surfaces.Therefore,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.展开更多
With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electro...With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electronic instruments.Therefore,the design and preparation of electromagnetic absorbing composites represent an efficient approach to mitigate the current hazards of electromagnetic radiation.However,traditional electromagnetic absorbers are difficult to satisfy the demands of actual utilization in the face of new challenges,and emerging absorbents have garnered increasing attention due to their structure and performance-based advantages.In this review,several emerging composites of Mxene-based,biochar-based,chiral,and heat-resisting are discussed in detail,including their synthetic strategy,structural superiority and regulation method,and final optimization of electromagnetic absorption ca-pacity.These insights provide a comprehensive reference for the future development of new-generation electromagnetic-wave absorption composites.Moreover,the potential development directions of these emerging absorbers have been proposed as well.展开更多
Reasonable manipulation of component and microstructure is considered as a potential route to realize high-performance microwave absorber.In this paper,micro-sized hexapod-like CuS/Cu_(9)S_(5) composites were synthesi...Reasonable manipulation of component and microstructure is considered as a potential route to realize high-performance microwave absorber.In this paper,micro-sized hexapod-like CuS/Cu_(9)S_(5) composites were synthesized via a facile approach involving the solvothermal method and subsequent sulfuration treatment.The resultant CuS/Cu_(9)S_(5) exhibited superb microwave absorbing capacity with a minimum reflection loss(RLmin)of-59.38 dB at 2.7 mm.The maximum effective absorption bandwidth(EABmax)was 7.44 GHz(10.56-18 GHz)when the thickness was reduced to 2.3 mm.The outstanding microwave absorbing ability of CuS/Cu_(9)S_(5) composites is mainly related to its unique hexapod shape and the formation of heterogeneous interfaces.The unique hexapod shape significantly promotes the multi-reflection of the incident electromagnetic wave(EMW)increasing the attenuation path of EMWs in the material.Hetero-geneous interfaces between CuS/Cu_(9)S_(5) enable powerful interface polarization,contributing to the atten-uation of EMWs propagating in the medium.In addition,the EMW absorption performance of CuS/Cu_(9)S_(5) composites is also inseparable from the conduction loss.This study provides a strong reference for the research of EMW absorbent materials based on transition metal sulfides.展开更多
Non-stoichiometric carbides have been proven to be effective electromagnetic wave(EMW)absorbing materials.In this study,phase and morphology of XZnC(X=Fe/Co/Cu)loaded on a three dimensional(3D)network structure melami...Non-stoichiometric carbides have been proven to be effective electromagnetic wave(EMW)absorbing materials.In this study,phase and morphology of XZnC(X=Fe/Co/Cu)loaded on a three dimensional(3D)network structure melamine sponge(MS)carbon composites were investigated through vacuum filtration followed by calcination.The FeZnC/CoZnC/CuZnC with carbon nanotubes(CNTs)were uniformly dispersed on the surface of melamine sponge carbon skeleton and Co-containing sample exhibits the highest CNTs concentration.The minimum reflection loss(RL_(min))of the CoZnC/MS composite(m_(composite):m_(paraffin)=1:1,m represents mass)reached-33.60 dB,and the effective absorption bandwidth(EAB)reached 9.60 GHz.The outstanding electromagnetic wave absorption(EMWA)properties of the CoZnC/MS composite can be attributed to its unique hollow structure,which leads to multiple reflections and scattering.The formed conductive network improves dielectric and conductive loss.The incorporation of Co enhances the magnetic loss capability and optimizes interfacial polarization and dipole polarization.By simultaneously improving dielectric and magnetic losses,ex-cellent impedance matching performance is achieved.The clarification of element replacement in XZnC/MS composites provides an effi-cient design perspective for high-performance non-stoichiometric carbide EMW absorbers.展开更多
With the booming development of electronic information science and 5G communication technology,electromagnetic radi-ation pollution poses a huge threat and damage to humanity.Developing novel and high-performance elec...With the booming development of electronic information science and 5G communication technology,electromagnetic radi-ation pollution poses a huge threat and damage to humanity.Developing novel and high-performance electromagnetic wave(EMW)ab-sorbers is an effective method to solve the above issue and has attracted the attention of many researchers.As a typical magnetic material,ferrite plays an important role in the design of high-performance EMW absorbers,and related research focuses on diversified synthesis methods,strong absorption performance,and refined microstructure development.Herein,we focus on the synthesis of ferrites and their composites and introduce recent advances in the high-temperature solid-phase method,sol-gel method,chemical coprecipitation method,and solvent thermal method in the preparation of high-performance EMW absorbers.This review aims to help researchers understand the advantages and disadvantages of ferrite-based EMW absorbers fabricated through these methods.It also provides important guidance and reference for researchers to design high-performance EMW absorption materials based on ferrite.展开更多
Demand for high-performance power devices continues to grow with the continuous development of power electronics and high-end field applications.Although packaging materials based on epoxy resins and silica gels have ...Demand for high-performance power devices continues to grow with the continuous development of power electronics and high-end field applications.Although packaging materials based on epoxy resins and silica gels have been widely developed,higher operating temperatures and operating voltages are still critical to the performance of power devices.Here,a composite film containing functionalized meso-porous hollow silica particles(MH-SiO_(2))and polyimide(PI)was prepared by a template method and layer-by-layer coating strategy to address the current bottlenecks in packaging material development.The electrical breakdown strength of the prepared PI/SiO_(2) composite film was 323.41 kV/mm,while the mass fraction of MH-SiO_(2) was only 5%.This indicates that the mesoporous structure can effectively inhibit electron collisions with nano-restricted domains.The simulation results also indicate that the size variation of inorganic fillers and the interaction of organic/inorganic heterogeneous interfaces are the main reasons affecting the performance of the composites.Meanwhile,the PI/SiO_(2) composite films achieved other properties required for practical applications,such as matched coefficient of thermal ex-pansion(CTE)(23.5 ppm/℃),excellent thermal stability(T_(5)%=559.0℃)and low dielectric constant(2.27@1 M Hz).These results highlight the great potential of inorganic phase-specific structural designs for the preparation of high-performance power device packaging materials.展开更多
Anion exchange membrane electrolysis (AEMWE) is currently a promising technology to produce hydrogen from water. Developing the highly intrinsic activity of electrodes is extremely important. In this paper, nitrogen v...Anion exchange membrane electrolysis (AEMWE) is currently a promising technology to produce hydrogen from water. Developing the highly intrinsic activity of electrodes is extremely important. In this paper, nitrogen vacancies-rich cobalt nitride (Co_(4)N-VN) is used as the anode catalyst of the urea oxidation reaction (UOR) and its loading Pt (Pt@Co_(4)N-VN) acted as the cathode of hydrogen evolution reaction (HER). The introduction of N-vacancies gained the electron-deficient Co_(4)N more favorable for the UOR process. Meanwhile, the electron transfer between the Co_(4)N-VN carrier and Pt can enhance the intrinsic HER activity of loaded Pt. Specifically, in the 0.33 M urea and 1.0 M KOH electrolyte, the UOR potential of CO_(4)N-VN is only 1.58 V at the current density of 300.0 mA cm^(-2), which is much lower than that of Co_(4) N and Co_(3)O_(4). At the same time, the HER overpotential at 1.0 M KOH and 300.0 mA cm^(-2) is only 120.0 mV, lower than 20 wt% Pt/C. By measuring the bode phase diagram, the presence of N-vacancies can accelerate the electron transfer rate of catalysts to improve the UOR and HER electrocatalytic activity. The overall water-splitting device featuring Pt@Co_(4)N-VN||Co_(4)N-VN electrodes achieves a voltage of 2.99 V at a current density of 300.0 mA cm^(-2).展开更多
In the face of the increasingly serious electromagnetic wave (EMW) pollution, a component modulation strategy is proposed in this study. By integrating ZIF-67 and FeOOH into MXene nanosheets and performing heat treatm...In the face of the increasingly serious electromagnetic wave (EMW) pollution, a component modulation strategy is proposed in this study. By integrating ZIF-67 and FeOOH into MXene nanosheets and performing heat treatment, a multiphase heterogeneous structure based on the multicomponent synergistic effect was successfully constructed. The synergistic effect of dielectric loss and magnetic loss is realized, and the rich heterogeneous interface and multi-scale structure significantly enhance the interface polarization and multiple scattering. The results show that the EMW absorption performance can be optimized by adjusting the composition of the composites. MXene@CoFe_(2)O_(4) exhibits a minimum reflection loss (RLmin) of -44.98 dB at 2.3 mm thickness and a maximum effective absorption bandwidth (EAB_(max)) of 4.64 GHz at 2.1 mm. MXene@CoFe_(2)O_(4)/CoFe composite has an RLmin of -55.14 dB at a thickness of 2.1 mm and an EAB_(max) of 5.60 GHz at a thickness of 1.9 mm. This work provides important insights into the development of wideband EMW absorbent materials.展开更多
The study of delicate nano-topological structures has been a prominent area of research,largely due to the distinctive electromagnetic characteristics of this structure.However,the relationship between topo-logical tr...The study of delicate nano-topological structures has been a prominent area of research,largely due to the distinctive electromagnetic characteristics of this structure.However,the relationship between topo-logical transformations,material properties,and electromagnetic wave(EMW)absorption performance remains insufficiently understood.In this study,a series of carbon fiber-based Co/MnO nanocomposites is derived from Co/Mn bimetal Prussian blue analogs encapsulated in polymer nanofiber networks by electrospinning.It has been demonstrated that various topological shapes can be modulated by modulat-ing surfactants,thereby changing the degree of graphitization and electrical conductivity.The optimized spherical precursor composite carbon fiber exhibits superior EMW absorption capability with minimum reflection loss(RL_(min))of-58.15 dB with a thickness of 2.3 mm.Moreover,ultrabroad effective absorption bandwidth(EAB)as large as 8.96 GHz is obtained.This work offers a significant contribution to the field of topology,while also promoting the development of manganese-based microwave-absorbing materials(MAMs)with enhanced electromagnetic absorption properties.展开更多
The development of next-generation electromagnetic wave(EMW)absorbers requires a shift in interface design.By employing hierarchical work function programming,we propose an approach to tune interfacial polarization dy...The development of next-generation electromagnetic wave(EMW)absorbers requires a shift in interface design.By employing hierarchical work function programming,we propose an approach to tune interfacial polarization dynamics.This method utilizes multi-gradient work functions to guide carrier migration and polarization effectively,thereby enhancing energy dissipation under alternating electromagnetic fields.Here,we constructed a 1T/2H-MoS_(2)/PPy/VS_(2) composite absorber with integrated gradient interfaces.The composite achieved a powerful absorption(RLmin)of-58.59 dB at 2.3 mm,and an effective absorption bandwidth(EAB)of 7.44 GHz at 2.5 mm,demonstrating improved broadband absorption.Radar cross-section(RCS)simulations show an EMW loss of-7.2 dB m^(2) at 0°,highlighting its potential for stealth and communication applications.This study introduces hierarchical work function programming as a promising strategy in EMW absorber design,contributing to advancements in material performance and functionality.展开更多
Metal nitrides exhibit excellent properties and application potential as electromagnetic wave(EMW)ab-sorbing materials.Their high conductivity and adjustable dielectric properties allow them to effectively attenuate E...Metal nitrides exhibit excellent properties and application potential as electromagnetic wave(EMW)ab-sorbing materials.Their high conductivity and adjustable dielectric properties allow them to effectively attenuate EMW.However,the current research on the synergistic effect of metal nitrides is scarce and has limited applications in the field of EMW absorption.In this work,Co/Ni metal-nitride fiber composites with multiphase structures were constructed by electrostatic spinning and multiphase composite process.The synergistic loss mechanism of multiphase structure and N atomic modulation is explored by modu-lating the components and microstructure of the materials.By constructing the multiphase composites,the controllable tuning of non-homogeneous interfaces and the enhanced interfacial polarization loss ef-fect were achieved.Electrochemical impedance spectroscopy was used to analyze the charge transfer ca-pability at the interface of multiphase Co/Ni metal nitride fiber composites.Through the controllable reg-ulation of the multiphase structure,the Co/Ni bimetallic nitride fiber composite(Co_(5.47)N/Ni_(4)N/CF)exhib-ited the strongest polarization loss capability,achieving a minimum reflection loss(RL_(min))of−43.82 dB and a maximum effective absorption bandwidth(EAB_(max))of 7.04 GHz.This study provides a valuable reference for multiphase composites in the field of EMW absorption by exploring the polarization loss mechanism of Co/Ni metal nitride multiphase materials.展开更多
Magnetic metal has broad application prospects in the field of electromagnetic wave(EMW)absorption due to its excellent dielectric and magnetic properties.However,high density and poor chemical stability constrain the...Magnetic metal has broad application prospects in the field of electromagnetic wave(EMW)absorption due to its excellent dielectric and magnetic properties.However,high density and poor chemical stability constrain their development potential.The combination of magnetic metals with other lightweight carbon materials is an effective solution.In this work,magnetic nanoparticle fiber composites were prepared by electrostatic spinning and high-temperature annealing processes.By adjusting the preparation process and annealing temperature,Co/Co7 Fe_(3)/CF-800 fiber composites containing double-shell hollow structured nanocubes were cleverly synthesized.The material is mixed with paraffin wax and has a minimum reflection loss(RL)of-52.14 dB and a maximum effective absorption bandwidth(EAB)of 6.16 GHz at a load of 10 wt%.By analyzing the electromagnetic parameters of the material,it was demonstrated that the material absorbs EMW through the synergistic effect of dielectric and magnetic losses.Electrochemical testing in a simulated seawater environment demonstrated that the material also has a degree of self-anticorrosion capability.This work provides new strategies for designing materials with excellent electromagnetic wave absorption and self-anticorrosion properties.展开更多
With the rapid development of 5G technology and the interconnection of industrial production,electro-magnetic pollution has become a serious problem.Achieving lightweight and controllable loads of ab-sorbers while obt...With the rapid development of 5G technology and the interconnection of industrial production,electro-magnetic pollution has become a serious problem.Achieving lightweight and controllable loads of ab-sorbers while obtaining corrosion-resistant absorbers with high electromagnetic response properties is still considered a huge challenge.In this work,carbon fiber with a multichannel hollow structure is ob-tained by PAN/PS hybrid electrospinning and subsequent high-temperature roasting process.The spatial structure inside the carbon fiber plays an active role in optimizing the impedance matching character-istics of the absorber.In addition,bimetallic metal-organic frameworks(MOFs)derivatives are obtained by a precisely controlled ion exchange as well as a high-temperature gas-phase selenization process.The resulting introduction of a non-homogeneous interface induces interfacial polarization and improves the absorption behavior of the absorber.The analysis of the experimental results shows that the electro-magnetic wave(EMW)absorption performance can be effectively enhanced due to the mechanisms of interface polarization and dipole polarization.The prepared NiSe/ZnSe/MHCFs composite can obtain ex-cellent EMW absorption properties in C,X,and Ku bands by adjusting the thickness.Structural design and component modulation play a crucial role in realizing the strong absorption and wide bandwidth of the absorber.Radar cross-section calculations indicate that NiSe/ZnSe/MHCFs have tremendous potential in practical military stealth technology.And the prepared composite coating can provide periodic corrosion resistance to Q235 steel sheet when dealing with complex and extreme environments.展开更多
Polymer dielectrics are required to maintain high energy density at elevated temperatures for advanced power and electronic systems.Herein,we report a novel solution-processed core-shell structured poly-imide(PI)nanoc...Polymer dielectrics are required to maintain high energy density at elevated temperatures for advanced power and electronic systems.Herein,we report a novel solution-processed core-shell structured poly-imide(PI)nanocomposite with moderate dielectric constant HfO_(2)core and wide-bandgap Al_(2)O_(3)shell,ef-fectively addressing the typical trade-off between dielectric constant and breakdown strength in dielectric nanocomposites predominant at elevated temperatures.The formation of improved dielectrically match-ing interfaces by the rationally designed dielectric constant gradient from core-shell-matrix remarkably mitigates the distortion of the electric field around the interfaces,resulting in a high breakdown strength.Wide band gap Al_(2)O_(3)shell also introduces deeper traps to impede the conduction loss.The validity of Al_(2)O_(3)shell has been proved via experiments and simulations.Accordingly,HfO_(2)@Al_(2)O_(3)/PI nanocompos-ite exhibits an excellent charge-discharge efficiency of 91.7%at 300 MV/m and a maximum discharged energy density of 2.94 J/cm^(3)at 150℃,demonstrating its potential for high-temperature energy storage.展开更多
The exponential growth of Internet of Things(IoT),wireless communication systems and the deployment of 5G networks has resulted in a significant increase in electromagnetic pollution,which has become a pressing global...The exponential growth of Internet of Things(IoT),wireless communication systems and the deployment of 5G networks has resulted in a significant increase in electromagnetic pollution,which has become a pressing global concern.The ubiquitous presence of electromagnetic wave(EMW)in the environment leads to electromagnetic interference(EMI),which can disrupt the normal operation of electronic devices and pose potential health risks to humans through prolonged exposure.展开更多
The development of wearable multifunctional electromagnetic protective fabrics with multifunctional,low cost,and high efficiency remains a challenge.Here,inspired by the unique flower branch shape of“Thunberg’s mead...The development of wearable multifunctional electromagnetic protective fabrics with multifunctional,low cost,and high efficiency remains a challenge.Here,inspired by the unique flower branch shape of“Thunberg’s meadowsweet”in nature,a nanofibrous composite membrane with hierarchical structure was constructed.Integrating sophisticated 0D@2D@1D hierarchical structures with multiple heterointerfaces can fully unleash the multifunctional application potential of composite membrane.The targeted induction method was used to precisely regulate the formation site and morphology of the metal–organic framework precursor,and intelligently integrate multiple heterostructures to enhance dielectric polarization,which improves the impedance matching and loss mechanisms of the electromagnetic wave absorbing materials.Due to the synergistic enhancement of electrospinning-derived carbon nanofiber“stems”,MOF-derived carbon nanosheet“petals”and transition metal selenide nano-particle“stamens”,the CoxSey/NiSe@CNSs@CNFs(CNCC)composite membrane obtains a minimum reflection loss value(RL_(min))of-68.40 dB at 2.6 mm and a maximum effective absorption bandwidth(EAB)of 8.88 GHz at a thin thickness of 2.0 mm with a filling amount of only 5 wt%.In addition,the multi-component and hierarchical heterostructure endow the fibrous membrane with excellent flexibility,water resistance,thermal management,and other multifunctional properties.This work provides unique perspectives for the precise design and rational application of multifunctional fabrics.展开更多
Application of novel radio technologies and equip-ment inevitably leads to electromagnetic pollution.One-dimensional polymer-based composite membrane structures have been shown to be an effective strategy to obtain hi...Application of novel radio technologies and equip-ment inevitably leads to electromagnetic pollution.One-dimensional polymer-based composite membrane structures have been shown to be an effective strategy to obtain high-performance microwave absorbers.Herein,we reported a one-dimensional N-doped carbon nanofibers material which encapsulated the hollow Co_(3)SnC_(0.7) nano-cubes in the fiber lumen by electrospinning.Space charge stacking formed between nanoparticles can be channeled by longitudinal fibrous structures.The dielectric constant of the fibers is highly related to the carbonization temperature,and the great impedance matching can be achieved by synergetic effect between Co_(3)SnC_(0.7) and carbon network.At 800℃,the necklace-like Co_(3)SnC_(0.7)/CNF with 5%low load achieves an excellent RL value of−51.2 dB at 2.3 mm and the effective absorption bandwidth of 7.44 GHz with matching thickness of 2.5 mm.The multiple electromagnetic wave(EMW)reflections and interfacial polarization between the fibers and the fibers internal contribute a major effect to attenuating the EMW.These strategies for regulating electromagnetic performance can be expanded to other electromagnetic functional materials which facilitate the development of emerging absorbers.展开更多
Cobalt ferrite(CoFe_(2)O_(4)),with good chemical stability and magnetic loss,can be used to prepare composites with a unique structure and high absorption.In this study,CoFe_(2)O_(4)@mesoporous carbon hollow spheres(M...Cobalt ferrite(CoFe_(2)O_(4)),with good chemical stability and magnetic loss,can be used to prepare composites with a unique structure and high absorption.In this study,CoFe_(2)O_(4)@mesoporous carbon hollow spheres(MCHS)with a core-shell structure were prepared by introducing CoFe_(2)O_(4)magnetic particles into hollow mesoporous carbon through a simple in situ method.Then,the microwave absorption performance of the CoFe_(2)O_(4)@MCHS composites was investigated.Magnetic and dielectric losses can be effectively coordinated by constructing the porous structure and adjusting the ratio of MCHS and CoFe_(2)O_(4).Results show that the impedance matching and absorption properties of the Co Fe_(2)O_(4)@MCHS composites can be altered by tweaking the mass ratio of MCHS and CoFe_(2)O_(4).The minimum reflection loss of the Co Fe_(2)O_(4)@MCHS composites reaches-29.7 dB at 5.8 GHz.In addition,the effective absorption bandwidth is 3.7 GHz,with the thickness being 2.5 mm.The boosted microwave absorption can be ascribed to the porous core-shell structure and introduction of magnetic particles.The coordination between the microporous morphology and the core-shell structure is conducive to improving the attenuation coefficient and achieving good impedance matching.The porous core-shell structure provides large solid-void and CoFe_(2)O_(4)-C interfaces to induce interfacial polarization and extend the electromagnetic waves’multiple scattering and reflection.Furthermore,natural resonance,exchange resonance,and eddy current loss work together for the magnetic loss.This method provides a practical solution to prepare core-shell structure microwave absorbents.展开更多
Layered double hydroxides(LDHs)have a special structure and atom composition,which are expected to be an excellent electromagnetic wave(EMW)absorber.However,it is still a problem that obtaining excellent EMWabsorbing ...Layered double hydroxides(LDHs)have a special structure and atom composition,which are expected to be an excellent electromagnetic wave(EMW)absorber.However,it is still a problem that obtaining excellent EMWabsorbing materials from LDHs.Herein,we designed heterostructure NiCo-LDHs@ZnO nanorod and then subsequent heat treating to derive NiCo@C/ZnO composites.Finally,with the synergy of excellent dielectric loss and magnetic loss,an outstanding absorption performance could be achieved with the reflection loss of−60.97 dB at the matching thickness of 2.3 mm,and the widest absorption bandwidth of 6.08 GHz was realized at 2.0 mm.Moreover,this research work provides a reference for the development and utilization of LDHs materials in the field of microwave absorption materials and can also provide ideas for the design of layered structural absorbers.展开更多
Although multifunctional aerogels are expected to be used in applications such as portable electronic devices,it is still a great challenge to confer multifunctionality to aerogels while maintaining their inherent mic...Although multifunctional aerogels are expected to be used in applications such as portable electronic devices,it is still a great challenge to confer multifunctionality to aerogels while maintaining their inherent microstructure.Herein,a simple method is proposed to prepare multifunctional NiCo/C aerogels with excellent electromagnetic wave absorption properties,superhydrophobicity,and self-cleaning by water-induced NiCo-MOF self-assembly.Specifically,the impedance matching of the three-dimensional(3D)structure and the interfacial polarization provided by CoNi/C as well as the defect-induced dipole polarization are the primary contributors to the broadband absorption.As a result,the prepared NiCo/C aerogels have a broadband width of 6.22 GHz at 1.9 mm.Due to the presence of hydrophobic functional groups,CoNi/C aerogels improve the stability in humid environments and obtain hydrophobicity with large contact angles>140°.This multifunctional aerogel has promising applications in electromagnetic wave absorption,resistance to water or humid environments.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52377026 and No.52301192)Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+4 种基金Postdoctoral Fellowship Program of CPSF under Grant Number(No.GZB20240327)Shandong Postdoctoral Science Foundation(No.SDCXZG-202400275)Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)China Postdoctoral Science Foundation(No.2024M751563)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites).
文摘Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is considered an effective means to achieve high-efficiency EMW absorption.However,interface modulation engineering has not been fully discussed and has great potential in the field of EMW absorption.In this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal reduction.By utilizing the different properties of different substances,rich heterogeneous interfaces are constructed.This effectively promotes charge transfer and enhances interfacial polarization and conduction loss.The prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy resin.The minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 GHz.Moreover,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel surfaces.Therefore,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.
基金supported by the Surface Project of Local De-velopment in Science and Technology Guided by Central Govern-ment(No.2021ZYD0041)the National Natural Science Founda-tion of China(Nos.52377026 and 52301192)+3 种基金the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Special Financial of Shandong Province(Struc-tural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Tal-ent Teams)the“Sanqin Scholars”Innovation Teams Project of Shaanxi Province(Clean Energy Materials and High-Performance Devices Innovation Team of Shaanxi Dongling Smelting Co.,Ltd.).
文摘With the increasing complexity of the current electromagnetic environment,excessive microwave radi-ation not only does harm to human health but also forms various electromagnetic interference to so-phisticated electronic instruments.Therefore,the design and preparation of electromagnetic absorbing composites represent an efficient approach to mitigate the current hazards of electromagnetic radiation.However,traditional electromagnetic absorbers are difficult to satisfy the demands of actual utilization in the face of new challenges,and emerging absorbents have garnered increasing attention due to their structure and performance-based advantages.In this review,several emerging composites of Mxene-based,biochar-based,chiral,and heat-resisting are discussed in detail,including their synthetic strategy,structural superiority and regulation method,and final optimization of electromagnetic absorption ca-pacity.These insights provide a comprehensive reference for the future development of new-generation electromagnetic-wave absorption composites.Moreover,the potential development directions of these emerging absorbers have been proposed as well.
基金supported by the National Natural Science Foundation of China(Nos.52377026 and 52301192)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+3 种基金the Postdoctoral Fellow-ship Program of CPSF under Grant Number(No.GZB20240327)the Shandong Postdoctoral Science Foundation(No.SDCX-ZG-202400275)the Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites).
文摘Reasonable manipulation of component and microstructure is considered as a potential route to realize high-performance microwave absorber.In this paper,micro-sized hexapod-like CuS/Cu_(9)S_(5) composites were synthesized via a facile approach involving the solvothermal method and subsequent sulfuration treatment.The resultant CuS/Cu_(9)S_(5) exhibited superb microwave absorbing capacity with a minimum reflection loss(RLmin)of-59.38 dB at 2.7 mm.The maximum effective absorption bandwidth(EABmax)was 7.44 GHz(10.56-18 GHz)when the thickness was reduced to 2.3 mm.The outstanding microwave absorbing ability of CuS/Cu_(9)S_(5) composites is mainly related to its unique hexapod shape and the formation of heterogeneous interfaces.The unique hexapod shape significantly promotes the multi-reflection of the incident electromagnetic wave(EMW)increasing the attenuation path of EMWs in the material.Hetero-geneous interfaces between CuS/Cu_(9)S_(5) enable powerful interface polarization,contributing to the atten-uation of EMWs propagating in the medium.In addition,the EMW absorption performance of CuS/Cu_(9)S_(5) composites is also inseparable from the conduction loss.This study provides a strong reference for the research of EMW absorbent materials based on transition metal sulfides.
基金supported by the National Natural Science Foundation of China(Nos.52101274,52377026 and 52472131)Taishan Scholars and Young Experts Program of Shandong Province,China(No.tsqn202103057)+4 种基金Natural Science Foundation of Shandong Province,China(Nos.ZR2020QE011 and ZR2022ME089)the Qingchuang Talents Induction Program of Shandong Higher Education Institution,China(Research and Innovation Team of Structural-Functional Polymer Composites)Youth Top Talent Foundation of Yantai University,China(No.2219008)Graduate Innovation Foundation of Yantai University,China(No.GIFYTU2240)College Student Innovation and Entrepreneurship Training Program Project,China(No.202311066088).
文摘Non-stoichiometric carbides have been proven to be effective electromagnetic wave(EMW)absorbing materials.In this study,phase and morphology of XZnC(X=Fe/Co/Cu)loaded on a three dimensional(3D)network structure melamine sponge(MS)carbon composites were investigated through vacuum filtration followed by calcination.The FeZnC/CoZnC/CuZnC with carbon nanotubes(CNTs)were uniformly dispersed on the surface of melamine sponge carbon skeleton and Co-containing sample exhibits the highest CNTs concentration.The minimum reflection loss(RL_(min))of the CoZnC/MS composite(m_(composite):m_(paraffin)=1:1,m represents mass)reached-33.60 dB,and the effective absorption bandwidth(EAB)reached 9.60 GHz.The outstanding electromagnetic wave absorption(EMWA)properties of the CoZnC/MS composite can be attributed to its unique hollow structure,which leads to multiple reflections and scattering.The formed conductive network improves dielectric and conductive loss.The incorporation of Co enhances the magnetic loss capability and optimizes interfacial polarization and dipole polarization.By simultaneously improving dielectric and magnetic losses,ex-cellent impedance matching performance is achieved.The clarification of element replacement in XZnC/MS composites provides an effi-cient design perspective for high-performance non-stoichiometric carbide EMW absorbers.
基金supported by the National Natural Science Foundation of China(No.52377026)Taishan Scholars and Young Experts Program of Shandong Province,China(No.tsqn202103057)the Natural Science Foundation of Shandong Province,China(No.ZR2024ME046).
文摘With the booming development of electronic information science and 5G communication technology,electromagnetic radi-ation pollution poses a huge threat and damage to humanity.Developing novel and high-performance electromagnetic wave(EMW)ab-sorbers is an effective method to solve the above issue and has attracted the attention of many researchers.As a typical magnetic material,ferrite plays an important role in the design of high-performance EMW absorbers,and related research focuses on diversified synthesis methods,strong absorption performance,and refined microstructure development.Herein,we focus on the synthesis of ferrites and their composites and introduce recent advances in the high-temperature solid-phase method,sol-gel method,chemical coprecipitation method,and solvent thermal method in the preparation of high-performance EMW absorbers.This review aims to help researchers understand the advantages and disadvantages of ferrite-based EMW absorbers fabricated through these methods.It also provides important guidance and reference for researchers to design high-performance EMW absorption materials based on ferrite.
基金supported by the National Natural Science Foundation of China(Nos.52377026 and 52301192)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+1 种基金the Natural Science Foundation of Shandong Province(Nos.ZR2024ME046 and ZR2024QE313)the China Postdoctoral Science Foundation(No.2024M761554).
文摘Demand for high-performance power devices continues to grow with the continuous development of power electronics and high-end field applications.Although packaging materials based on epoxy resins and silica gels have been widely developed,higher operating temperatures and operating voltages are still critical to the performance of power devices.Here,a composite film containing functionalized meso-porous hollow silica particles(MH-SiO_(2))and polyimide(PI)was prepared by a template method and layer-by-layer coating strategy to address the current bottlenecks in packaging material development.The electrical breakdown strength of the prepared PI/SiO_(2) composite film was 323.41 kV/mm,while the mass fraction of MH-SiO_(2) was only 5%.This indicates that the mesoporous structure can effectively inhibit electron collisions with nano-restricted domains.The simulation results also indicate that the size variation of inorganic fillers and the interaction of organic/inorganic heterogeneous interfaces are the main reasons affecting the performance of the composites.Meanwhile,the PI/SiO_(2) composite films achieved other properties required for practical applications,such as matched coefficient of thermal ex-pansion(CTE)(23.5 ppm/℃),excellent thermal stability(T_(5)%=559.0℃)and low dielectric constant(2.27@1 M Hz).These results highlight the great potential of inorganic phase-specific structural designs for the preparation of high-performance power device packaging materials.
基金supported by the National Natural Science Foundation of China(Nos.52302272 and 52377026)the Taishan Scholars Program(Nos.tsqn202211124 and tsqn202103057)+4 种基金the Natural Science Foundation of Shandong Province(Nos.ZR2022QB023 and ZR2024ME046)the Qingchuang Talents Induction Program of Shandong Higher Education Insti-tution(Research and Innovation Team of Marine Polysaccharides Fibers-based Energy Materials)the Key Innovative Research Team of New Energy Materials and Devices(No.BBXYKYTDxjZD01)the University Natural Science Research Project of Anhui Province(No.2022AH010101)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZKT10 and GZRC202006).
文摘Anion exchange membrane electrolysis (AEMWE) is currently a promising technology to produce hydrogen from water. Developing the highly intrinsic activity of electrodes is extremely important. In this paper, nitrogen vacancies-rich cobalt nitride (Co_(4)N-VN) is used as the anode catalyst of the urea oxidation reaction (UOR) and its loading Pt (Pt@Co_(4)N-VN) acted as the cathode of hydrogen evolution reaction (HER). The introduction of N-vacancies gained the electron-deficient Co_(4)N more favorable for the UOR process. Meanwhile, the electron transfer between the Co_(4)N-VN carrier and Pt can enhance the intrinsic HER activity of loaded Pt. Specifically, in the 0.33 M urea and 1.0 M KOH electrolyte, the UOR potential of CO_(4)N-VN is only 1.58 V at the current density of 300.0 mA cm^(-2), which is much lower than that of Co_(4) N and Co_(3)O_(4). At the same time, the HER overpotential at 1.0 M KOH and 300.0 mA cm^(-2) is only 120.0 mV, lower than 20 wt% Pt/C. By measuring the bode phase diagram, the presence of N-vacancies can accelerate the electron transfer rate of catalysts to improve the UOR and HER electrocatalytic activity. The overall water-splitting device featuring Pt@Co_(4)N-VN||Co_(4)N-VN electrodes achieves a voltage of 2.99 V at a current density of 300.0 mA cm^(-2).
基金supported by the National Nat-ural Science Foundation of China(No.52377026)the Tais-han Scholars Program(No.tsqn202103057)+6 种基金the Natural Sci-ence Foundation of Shandong Province(No.ZR2024ME046)the Postdoctoral Fellowship Program of CPSF(No.GZB20240327)the Shandong Postdoctoral Science Foundation(No.SDCX-ZG-202400275)the Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)the Postdoctoral Science Foundation of China(No.2024M751563)the Key Innovative Research Team of New Energy Materials and Devices(No.BBXYKYTDxjZD01)the University Natural Science Research Project of Anhui Province(No.2022AH010101).
文摘In the face of the increasingly serious electromagnetic wave (EMW) pollution, a component modulation strategy is proposed in this study. By integrating ZIF-67 and FeOOH into MXene nanosheets and performing heat treatment, a multiphase heterogeneous structure based on the multicomponent synergistic effect was successfully constructed. The synergistic effect of dielectric loss and magnetic loss is realized, and the rich heterogeneous interface and multi-scale structure significantly enhance the interface polarization and multiple scattering. The results show that the EMW absorption performance can be optimized by adjusting the composition of the composites. MXene@CoFe_(2)O_(4) exhibits a minimum reflection loss (RLmin) of -44.98 dB at 2.3 mm thickness and a maximum effective absorption bandwidth (EAB_(max)) of 4.64 GHz at 2.1 mm. MXene@CoFe_(2)O_(4)/CoFe composite has an RLmin of -55.14 dB at a thickness of 2.1 mm and an EAB_(max) of 5.60 GHz at a thickness of 1.9 mm. This work provides important insights into the development of wideband EMW absorbent materials.
基金supported by the National Natural Science Foundation of China(Nos.52377026 and 52301192)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+4 种基金the Natural Science Foundation of Shan-dong Province(Nos.ZR2024ME046 and ZR2024QE313)Postdoc-toral Fellowship Program of CPSF(No.GZB20240327)the Post-doctoral Science Foundation of Shandong Province(No.SDCX-ZG-202400275)the Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)Postdoctoral Science Foundation of China(Nos.2024M751563 and 2024M761554).
文摘The study of delicate nano-topological structures has been a prominent area of research,largely due to the distinctive electromagnetic characteristics of this structure.However,the relationship between topo-logical transformations,material properties,and electromagnetic wave(EMW)absorption performance remains insufficiently understood.In this study,a series of carbon fiber-based Co/MnO nanocomposites is derived from Co/Mn bimetal Prussian blue analogs encapsulated in polymer nanofiber networks by electrospinning.It has been demonstrated that various topological shapes can be modulated by modulat-ing surfactants,thereby changing the degree of graphitization and electrical conductivity.The optimized spherical precursor composite carbon fiber exhibits superior EMW absorption capability with minimum reflection loss(RL_(min))of-58.15 dB with a thickness of 2.3 mm.Moreover,ultrabroad effective absorption bandwidth(EAB)as large as 8.96 GHz is obtained.This work offers a significant contribution to the field of topology,while also promoting the development of manganese-based microwave-absorbing materials(MAMs)with enhanced electromagnetic absorption properties.
基金supported by the National Natural Science Foundation of China(Nos.22275156,52025132,21,621,091,52300138,22021001 and 22121001)the Fundamental Research Funds for the Central Universities of China(No.20720220019)+2 种基金the National Science Foundation of Fujian Province of China(No.2022J02059)the 111 Project(Nos.B17027,B16029)the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘The development of next-generation electromagnetic wave(EMW)absorbers requires a shift in interface design.By employing hierarchical work function programming,we propose an approach to tune interfacial polarization dynamics.This method utilizes multi-gradient work functions to guide carrier migration and polarization effectively,thereby enhancing energy dissipation under alternating electromagnetic fields.Here,we constructed a 1T/2H-MoS_(2)/PPy/VS_(2) composite absorber with integrated gradient interfaces.The composite achieved a powerful absorption(RLmin)of-58.59 dB at 2.3 mm,and an effective absorption bandwidth(EAB)of 7.44 GHz at 2.5 mm,demonstrating improved broadband absorption.Radar cross-section(RCS)simulations show an EMW loss of-7.2 dB m^(2) at 0°,highlighting its potential for stealth and communication applications.This study introduces hierarchical work function programming as a promising strategy in EMW absorber design,contributing to advancements in material performance and functionality.
基金supported by the National Natural Science Foundation of China(Nos.52377026 and 52301192)the Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+4 种基金the Natural Science Foundation of Shandong Province(Nos.ZR2024ME046 andZR2024QE313)the Post-doctoral Fellowship Program of CPSF(No.GZB20240327)the Post-doctoral Science Foundation of Shandong Province(No.SDCX-ZG-202400275)the Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)Postdoctoral Science Foundation of China(Nos.2024M751563 and 2024M761554).
文摘Metal nitrides exhibit excellent properties and application potential as electromagnetic wave(EMW)ab-sorbing materials.Their high conductivity and adjustable dielectric properties allow them to effectively attenuate EMW.However,the current research on the synergistic effect of metal nitrides is scarce and has limited applications in the field of EMW absorption.In this work,Co/Ni metal-nitride fiber composites with multiphase structures were constructed by electrostatic spinning and multiphase composite process.The synergistic loss mechanism of multiphase structure and N atomic modulation is explored by modu-lating the components and microstructure of the materials.By constructing the multiphase composites,the controllable tuning of non-homogeneous interfaces and the enhanced interfacial polarization loss ef-fect were achieved.Electrochemical impedance spectroscopy was used to analyze the charge transfer ca-pability at the interface of multiphase Co/Ni metal nitride fiber composites.Through the controllable reg-ulation of the multiphase structure,the Co/Ni bimetallic nitride fiber composite(Co_(5.47)N/Ni_(4)N/CF)exhib-ited the strongest polarization loss capability,achieving a minimum reflection loss(RL_(min))of−43.82 dB and a maximum effective absorption bandwidth(EAB_(max))of 7.04 GHz.This study provides a valuable reference for multiphase composites in the field of EMW absorption by exploring the polarization loss mechanism of Co/Ni metal nitride multiphase materials.
基金supported by the National Natural Science Foundation of China(Nos.52377026 and 52301192)Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites).
文摘Magnetic metal has broad application prospects in the field of electromagnetic wave(EMW)absorption due to its excellent dielectric and magnetic properties.However,high density and poor chemical stability constrain their development potential.The combination of magnetic metals with other lightweight carbon materials is an effective solution.In this work,magnetic nanoparticle fiber composites were prepared by electrostatic spinning and high-temperature annealing processes.By adjusting the preparation process and annealing temperature,Co/Co7 Fe_(3)/CF-800 fiber composites containing double-shell hollow structured nanocubes were cleverly synthesized.The material is mixed with paraffin wax and has a minimum reflection loss(RL)of-52.14 dB and a maximum effective absorption bandwidth(EAB)of 6.16 GHz at a load of 10 wt%.By analyzing the electromagnetic parameters of the material,it was demonstrated that the material absorbs EMW through the synergistic effect of dielectric and magnetic losses.Electrochemical testing in a simulated seawater environment demonstrated that the material also has a degree of self-anticorrosion capability.This work provides new strategies for designing materials with excellent electromagnetic wave absorption and self-anticorrosion properties.
基金supported by the National Natural Sci-ence Foundation of China(Nos.52377026 and 52301192)Tais-han Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+4 种基金Postdoctoral Fellowship Program of CPSF(No.GZB20240327)Shandong Postdoctoral Science Foundation(No.SDCX-ZG-202400275)Qingdao Postdoctoral Application Re-search Project(No.QDBSH20240102023)China Postdoctoral Sci-ence Foundation(No.2024M751563)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Re-search and Innovation Team of Structural-Functional Polymer Composites).
文摘With the rapid development of 5G technology and the interconnection of industrial production,electro-magnetic pollution has become a serious problem.Achieving lightweight and controllable loads of ab-sorbers while obtaining corrosion-resistant absorbers with high electromagnetic response properties is still considered a huge challenge.In this work,carbon fiber with a multichannel hollow structure is ob-tained by PAN/PS hybrid electrospinning and subsequent high-temperature roasting process.The spatial structure inside the carbon fiber plays an active role in optimizing the impedance matching character-istics of the absorber.In addition,bimetallic metal-organic frameworks(MOFs)derivatives are obtained by a precisely controlled ion exchange as well as a high-temperature gas-phase selenization process.The resulting introduction of a non-homogeneous interface induces interfacial polarization and improves the absorption behavior of the absorber.The analysis of the experimental results shows that the electro-magnetic wave(EMW)absorption performance can be effectively enhanced due to the mechanisms of interface polarization and dipole polarization.The prepared NiSe/ZnSe/MHCFs composite can obtain ex-cellent EMW absorption properties in C,X,and Ku bands by adjusting the thickness.Structural design and component modulation play a crucial role in realizing the strong absorption and wide bandwidth of the absorber.Radar cross-section calculations indicate that NiSe/ZnSe/MHCFs have tremendous potential in practical military stealth technology.And the prepared composite coating can provide periodic corrosion resistance to Q235 steel sheet when dealing with complex and extreme environments.
基金supported by the National Natu-ral Science Foundation of China(Nos.52107232 and 52377026)China Postdoctoral Science Foundation(No.2021M702563)+2 种基金State Key Laboratory of Electrical Insulation and Power Equipment(No.EIPE22312)Taishan Scholars and Young Experts Program of Shan-dong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)and Fundamental Research Funds for the Central Universities(No.xzy012024004).
文摘Polymer dielectrics are required to maintain high energy density at elevated temperatures for advanced power and electronic systems.Herein,we report a novel solution-processed core-shell structured poly-imide(PI)nanocomposite with moderate dielectric constant HfO_(2)core and wide-bandgap Al_(2)O_(3)shell,ef-fectively addressing the typical trade-off between dielectric constant and breakdown strength in dielectric nanocomposites predominant at elevated temperatures.The formation of improved dielectrically match-ing interfaces by the rationally designed dielectric constant gradient from core-shell-matrix remarkably mitigates the distortion of the electric field around the interfaces,resulting in a high breakdown strength.Wide band gap Al_(2)O_(3)shell also introduces deeper traps to impede the conduction loss.The validity of Al_(2)O_(3)shell has been proved via experiments and simulations.Accordingly,HfO_(2)@Al_(2)O_(3)/PI nanocompos-ite exhibits an excellent charge-discharge efficiency of 91.7%at 300 MV/m and a maximum discharged energy density of 2.94 J/cm^(3)at 150℃,demonstrating its potential for high-temperature energy storage.
文摘The exponential growth of Internet of Things(IoT),wireless communication systems and the deployment of 5G networks has resulted in a significant increase in electromagnetic pollution,which has become a pressing global concern.The ubiquitous presence of electromagnetic wave(EMW)in the environment leads to electromagnetic interference(EMI),which can disrupt the normal operation of electronic devices and pose potential health risks to humans through prolonged exposure.
基金supported by the National Natural Science Foundation of China(No.51407134,No.52002196)Natural Science Foundation of Shandong Province(No.ZR2019YQ24,No.ZR2020QF084)+2 种基金Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)Special Financial of Shandong Province(Structural Design of Highefficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams(No.37000022P990304116449)).
文摘The development of wearable multifunctional electromagnetic protective fabrics with multifunctional,low cost,and high efficiency remains a challenge.Here,inspired by the unique flower branch shape of“Thunberg’s meadowsweet”in nature,a nanofibrous composite membrane with hierarchical structure was constructed.Integrating sophisticated 0D@2D@1D hierarchical structures with multiple heterointerfaces can fully unleash the multifunctional application potential of composite membrane.The targeted induction method was used to precisely regulate the formation site and morphology of the metal–organic framework precursor,and intelligently integrate multiple heterostructures to enhance dielectric polarization,which improves the impedance matching and loss mechanisms of the electromagnetic wave absorbing materials.Due to the synergistic enhancement of electrospinning-derived carbon nanofiber“stems”,MOF-derived carbon nanosheet“petals”and transition metal selenide nano-particle“stamens”,the CoxSey/NiSe@CNSs@CNFs(CNCC)composite membrane obtains a minimum reflection loss value(RL_(min))of-68.40 dB at 2.6 mm and a maximum effective absorption bandwidth(EAB)of 8.88 GHz at a thin thickness of 2.0 mm with a filling amount of only 5 wt%.In addition,the multi-component and hierarchical heterostructure endow the fibrous membrane with excellent flexibility,water resistance,thermal management,and other multifunctional properties.This work provides unique perspectives for the precise design and rational application of multifunctional fabrics.
基金financially supported by the Natural Science Foundation of Shandong Province (No. ZR2019YQ24)Taishan Scholars and Young Experts Program of Shandong Province (No.tsqn202103057)+1 种基金the Qingchuang Talents Induction Program of Shandong Higher Education Institution (Research and Innovation Team of Structural-Functional Polymer Composites)Special Financial of Shandong Province (Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams)
文摘Application of novel radio technologies and equip-ment inevitably leads to electromagnetic pollution.One-dimensional polymer-based composite membrane structures have been shown to be an effective strategy to obtain high-performance microwave absorbers.Herein,we reported a one-dimensional N-doped carbon nanofibers material which encapsulated the hollow Co_(3)SnC_(0.7) nano-cubes in the fiber lumen by electrospinning.Space charge stacking formed between nanoparticles can be channeled by longitudinal fibrous structures.The dielectric constant of the fibers is highly related to the carbonization temperature,and the great impedance matching can be achieved by synergetic effect between Co_(3)SnC_(0.7) and carbon network.At 800℃,the necklace-like Co_(3)SnC_(0.7)/CNF with 5%low load achieves an excellent RL value of−51.2 dB at 2.3 mm and the effective absorption bandwidth of 7.44 GHz with matching thickness of 2.5 mm.The multiple electromagnetic wave(EMW)reflections and interfacial polarization between the fibers and the fibers internal contribute a major effect to attenuating the EMW.These strategies for regulating electromagnetic performance can be expanded to other electromagnetic functional materials which facilitate the development of emerging absorbers.
基金supported by the National Natural Science Foundation of China(No.51407134)the Sichuan Science and Technology Program(No.2021108)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2019YQ24)the Taishan Scholars and Young Experts Program of Shandong Province。
文摘Cobalt ferrite(CoFe_(2)O_(4)),with good chemical stability and magnetic loss,can be used to prepare composites with a unique structure and high absorption.In this study,CoFe_(2)O_(4)@mesoporous carbon hollow spheres(MCHS)with a core-shell structure were prepared by introducing CoFe_(2)O_(4)magnetic particles into hollow mesoporous carbon through a simple in situ method.Then,the microwave absorption performance of the CoFe_(2)O_(4)@MCHS composites was investigated.Magnetic and dielectric losses can be effectively coordinated by constructing the porous structure and adjusting the ratio of MCHS and CoFe_(2)O_(4).Results show that the impedance matching and absorption properties of the Co Fe_(2)O_(4)@MCHS composites can be altered by tweaking the mass ratio of MCHS and CoFe_(2)O_(4).The minimum reflection loss of the Co Fe_(2)O_(4)@MCHS composites reaches-29.7 dB at 5.8 GHz.In addition,the effective absorption bandwidth is 3.7 GHz,with the thickness being 2.5 mm.The boosted microwave absorption can be ascribed to the porous core-shell structure and introduction of magnetic particles.The coordination between the microporous morphology and the core-shell structure is conducive to improving the attenuation coefficient and achieving good impedance matching.The porous core-shell structure provides large solid-void and CoFe_(2)O_(4)-C interfaces to induce interfacial polarization and extend the electromagnetic waves’multiple scattering and reflection.Furthermore,natural resonance,exchange resonance,and eddy current loss work together for the magnetic loss.This method provides a practical solution to prepare core-shell structure microwave absorbents.
基金financially supported by the National Natural Science Foundation of China(No.51407134)Natural Science Foundation of Shandong Province(No.ZR2019YQ24)+3 种基金Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)China Postdoctoral Science Foundation(No.2016M590619)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)The authors acknowledge the support from The Thousand Talents Plan,The World-Class University and Discipline,The Taishan Scholar’s Advantageous and Distinctive Discipline Program of Shandong Province and The World-Class Discipline Program of Shandong Province.
文摘Layered double hydroxides(LDHs)have a special structure and atom composition,which are expected to be an excellent electromagnetic wave(EMW)absorber.However,it is still a problem that obtaining excellent EMWabsorbing materials from LDHs.Herein,we designed heterostructure NiCo-LDHs@ZnO nanorod and then subsequent heat treating to derive NiCo@C/ZnO composites.Finally,with the synergy of excellent dielectric loss and magnetic loss,an outstanding absorption performance could be achieved with the reflection loss of−60.97 dB at the matching thickness of 2.3 mm,and the widest absorption bandwidth of 6.08 GHz was realized at 2.0 mm.Moreover,this research work provides a reference for the development and utilization of LDHs materials in the field of microwave absorption materials and can also provide ideas for the design of layered structural absorbers.
基金financially supported by the National Natural Science Foundation of China (No.51407134, No.52002196)Natural Science Foundation of Shandong Province (No.ZR2019YQ24, No.ZR2020QF084)+2 种基金Taishan Scholars and Young Experts Program of Shandong Province (No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution (Research and Innovation Team of Structural-Functional Polymer Composites)Special Financial of Shandong Province (Structural Design of Highefficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams (No. 37000022P990304116449))
文摘Although multifunctional aerogels are expected to be used in applications such as portable electronic devices,it is still a great challenge to confer multifunctionality to aerogels while maintaining their inherent microstructure.Herein,a simple method is proposed to prepare multifunctional NiCo/C aerogels with excellent electromagnetic wave absorption properties,superhydrophobicity,and self-cleaning by water-induced NiCo-MOF self-assembly.Specifically,the impedance matching of the three-dimensional(3D)structure and the interfacial polarization provided by CoNi/C as well as the defect-induced dipole polarization are the primary contributors to the broadband absorption.As a result,the prepared NiCo/C aerogels have a broadband width of 6.22 GHz at 1.9 mm.Due to the presence of hydrophobic functional groups,CoNi/C aerogels improve the stability in humid environments and obtain hydrophobicity with large contact angles>140°.This multifunctional aerogel has promising applications in electromagnetic wave absorption,resistance to water or humid environments.
