Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR clo...Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR cloaking mechanisms and functional integration limitations.Here,we propose a multiscale hierarchical structure design,integrating wrinkled MXene IR shielding layer and flexible Fe_(3)O_(4)@C/PDMS microwave absorption layer.The top wrinkled MXene layer induces the intensive diffuse reflection effect,shielding IR radiation signals while allowing microwave to pass through.Meanwhile,the permeable microwaves are assimilated into the bottom Fe_(3)O_(4)@C/PDMS layer via strong magneto-electric synergy.Through theoretical and experimental optimization,the assembled stealth devices realize a near-perfect stealth capability in both X-band(8–12 GHz)and long-wave infrared(8–14μm)wavelength ranges.Specifically,it delivers a radar cross-section reduction of−20 dB m^(2),a large apparent temperature modulation range(ΔT=70℃),and a low average IR emissivity of 0.35.Additionally,the optimal device demonstrates exceptional curved surface conformability,self-cleaning capability(contact angle≈129°),and abrasion resistance(recovery time≈5 s).This design strategy promotes the development of multispectral stealth technology and reinforces its applicability and durability in complex and hostile environments.展开更多
Exploring high-efficiency and broadband microwave absorption(MA)materials with corrosion resistance and low cost is ur-gently needed for wide practical applications.Herein,the natural porous attapulgite(ATP)nanorods e...Exploring high-efficiency and broadband microwave absorption(MA)materials with corrosion resistance and low cost is ur-gently needed for wide practical applications.Herein,the natural porous attapulgite(ATP)nanorods embedded with TiO_(2)and polyaniline(PANI)nanoparticles are synthesized via heterogeneous precipitation and in-situ polymerization.The obtained PANI-TiO_(2)-ATP one-di-mensional(1D)nanostructures can intertwine into three-dimensional(3D)conductive network,which favors energy dissipation.The min-imum reflection loss(RL_(min))of the PANI-TiO_(2)-ATP coating(20wt%)reaches-49.36 dB at 9.53 GHz,and the effective absorption band-width(EAB)can reach 6.53 GHz with a thickness of 2.1 mm.The excellent MA properties are attributed to interfacial polarization,mul-tiple loss mechanisms,and good impedance matching induced by the synergistic effect of PANI-TiO_(2)nanoparticle shells and ATP nanor-ods.In addition,salt spray and Tafel polarization curve tests reveal that the PANI-TiO_(2)-ATP coating shows outstanding corrosion resist-ance performance.This study provides a low-cost and high-efficiency strategy for constructing 1D nanonetwork composites for MA and corrosion resistance applications using natural porous ATP nanorods as carriers.展开更多
Exploring efficient microwave absorbing materials(MAMs)has gradually become a hot topic in recent years because it is crucial in both civil and military fields.Metal-organic framework(MOF)has great potential due to it...Exploring efficient microwave absorbing materials(MAMs)has gradually become a hot topic in recent years because it is crucial in both civil and military fields.Metal-organic framework(MOF)has great potential due to its unique composition and bonding mode,which has advantages such as large specific surface area,high porosity,adjustable structure,and designable composition.Herein,MOF-derived MAMs are highlighted based on morphology and structure.The synthesis strategies of MOF-derived MAMs of different dimensions are discussed.On this basis,the structure-activity relationships can be deeply explored through the precise control of material structure and property by atomic engineering.Finally,perspectives are given for the existing problems of MOF-derived MAMs,which will open a new horizon and promote the development of MAMs.展开更多
There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and grea...There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and great surface conformability.To meet these requirements,we designed and fabricated a flexible bioinspired meta-structure with ultra-broadband MA,thin thickness and excellent surface conformality.The carbonyl iron powder-carbon nanotubes-polydimethylsiloxane composite was synthesized by physical blending method for fabricating the MA meta-structure.Through geometry-electromagnetic optimal design by heuristic optimization algorithm,the meta-structure mimicking to the nipple photonic nanostructures on the eyes of moth can achieve ultra-broadband MA performance of 35.14 GHz MA bandwidth(reflection loss≤–10 dB),covering 4.86–40.00 GHz,with thickness of only 4.3 mm.Through simple fabrication processes,the meta-structure has been successfully fabricated and bonded on wings’leading edges,exhibiting excellent surface conformability.Furthermore,the designed flexible MA meta-structure possesses significant Radar Cross-Section(RCS)reduction capability,as demonstrated by the RCS analysis of an unmanned aerial vehicle.This flexible ultra-broadband MA meta-structure provides an outstanding candidate to meet the radar stealth requirement of variable curvature structures on aircraft.展开更多
Inspired by the remarkable electromagnetic response capabilities of the complex morphologies and subtle microstructures evolved by natural organisms,this paper delves into the research advancements and future applicat...Inspired by the remarkable electromagnetic response capabilities of the complex morphologies and subtle microstructures evolved by natural organisms,this paper delves into the research advancements and future application potential of bionic microwave-absorbing materials(BMAMs).It outlines the significance of achieving high-performance microwave-absorbing materials through ingenious microstructural design and judicious composition selection,while emphasizing the innovative strategies offered by bionic manufacturing.Furthermore,this work meticulously analyzes how inspiration can be drawn from the intricate structures of marine organisms,plants,animals,and nonmetallic minerals in nature to devise and develop BMAMs with superior electromagnetic wave absorption properties.Additionally,the paper provides an in-depth exploration of the theoretical underpinnings of BMAMs,particularly the latest breakthroughs in broadband absorption.By incorporating advanced methodologies such as simulation modeling and bionic gradient design,we unravel the scientific principles governing the microwave absorption mechanisms of BMAMs,thereby furnishing a solid theoretical foundation for understanding and optimizing their performance.Ultimately,this review aims to offer valuable insights and inspiration to researchers in related fields,fostering the collective advancement of research on BMAMs.展开更多
Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_...Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal method.Various mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these composites.Consequently,compared with pure residual carbon materials,this composite offers superior capabilities in microwave absorption.At 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 mm.Moreover,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of 1.18mm.This study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.展开更多
The previous studies mainly focused on improving microwave absorbing(MA)performances of MA materials.Even so,these designed MA materials were very difficult to be employed in complex and changing environments owing to...The previous studies mainly focused on improving microwave absorbing(MA)performances of MA materials.Even so,these designed MA materials were very difficult to be employed in complex and changing environments owing to their single-functionalities.Herein,a combined Prussian blue analogues derived and catalytical chemical vapor deposition strategy was proposed to produce hierarchical cubic sea urchin-like yolk–shell CoNi@Ndoped carbon(NC)-CoNi@carbon nanotubes(CNTs)mixed-dimensional multicomponent nanocomposites(MCNCs),which were composed of zerodimensional CoNi nanoparticles,three-dimensional NC nanocubes and onedimensional CNTs.Because of good impedance matching and attenuation characteristics,the designed CoNi@NC-CoNi@CNTs mixed-dimensional MCNCs exhibited excellent MA performances,which achieved a minimum reflection loss(RL_(min))of−71.70 dB at 2.78 mm and Radar Cross section value of−53.23 dB m^(2).More importantly,the acquired results demonstrated that CoNi@NC-CoNi@CNTs MCNCs presented excellent photothermal,antimicrobial and anti-corrosion properties owing to their hierarchical cubic sea urchin-like yolk–shell structure,highlighting their potential multifunctional applications.It could be seen that this finding not only presented a generalizable route to produce hierarchical cubic sea urchin-like yolk–shell magnetic NC-CNTs-based mixed-dimensional MCNCs,but also provided an effective strategy to develop multifunctional MCNCs and improve their environmental adaptabilities.展开更多
Carbon materials have made significant progress in the field of microwave absorption(MA),but achieving wide effective absorption bandwidth(EAB)at low filler content still remains a great challenge.In this work,we desi...Carbon materials have made significant progress in the field of microwave absorption(MA),but achieving wide effective absorption bandwidth(EAB)at low filler content still remains a great challenge.In this work,we design multi-shell bowl-like mesoporous carbon microspheres(MBMCs)by a facile hard template method for efficient MA.It is demonstrated that the spacing between inner and outer shell and second shell thickness play a vital role on the configuration of carbon microspheres.By controlling the second addition of silica template,the microstructure of carbon microsphere evolves from spherical to bowl shape geometry.Expanded shell spacing is beneficial for forming bowl-like microsphere.The dielectric loss and MA properties are highly associated with the configuration of MBMCs.Well-proportioned MBMCs with appropriate shell spacing present wide EAB of 7.3 GHz under a low filling ratio of 12 wt.%.This work paves a new way to broaden EAB and lower filling content of carbon materials via asymmetric multilayer microstructure design.展开更多
Lightweight materials with wide absorption capabilities,particularly in the C-band,have remained a challenge thus far.Recent research has indicated that effective absorption networks built by microfiber polarization l...Lightweight materials with wide absorption capabilities,particularly in the C-band,have remained a challenge thus far.Recent research has indicated that effective absorption networks built by microfiber polarization loss can be a significant factor in increasing the effective absorption bandwidth(EAB).In this study,leaf vein-like carbon(LVC)was synthesized using an in situ blowing strategy.Taking inspiration from photosynthesis energy conversion mechanisms,a leaf veins-like hierarchical structure was created to establish an effective impedance-matching network and generate a high-density polarization region through leaf vein microfibers.This enhanced polarization relaxation effectively broadens the EAB of the LVC.At a low filling ratio of 6.3 wt%,the EAB of the LVC covers 80%of the C-band,as well as100%of the X-band and Ku-band.Achieving such a wide EAB in the C-band,especially in the multi-band context,relies on impedance matching and optimized polarization relaxation.This work demonstrates the crucial role of leaf vein micronetwork engineering in enhancing the C-band absorption properties of carbon-based materials,thus providing a viable reference for the development of lightweight,broadband,and highly absorptive materials for electromagnetic applications.展开更多
Heterojunction and morphology control assume a significant part in adjusting the intrinsic electromagnetic properties of absorbers to acquire outstanding microwave absorption(MA)performance,but this still faces huge c...Heterojunction and morphology control assume a significant part in adjusting the intrinsic electromagnetic properties of absorbers to acquire outstanding microwave absorption(MA)performance,but this still faces huge challenges.Herein,FeS_(2)/C/MoS_(2)composite with core–shell structure was successfully designed and prepared via a multi-interface engineering.MoS_(2)nanosheets with 1T and 2H phases are coated on the outside of FeS_(2)/C to form a porous interconnected structure that can optimize the impedance matching characteristics and strengthen the interfacial polarization loss capacity.Remarkably,as-fabricated FCM-3 harvests a broad effective absorption bandwidth(EAB)of 5.12 GHz and a minimum reflection loss(RL_(min))value of-45.1 d B.Meanwhile,FCM-3 can accomplish a greatest radar cross section(RCS)reduction value of 18.52 d B m^(2)when the detection angle is 0°.Thus,the convenient computer simulation technology(CST)simulations and encouraging accomplishments provide a novel avenue for the further development of efficient and lightweight MA materials.展开更多
Multiscale shell structure design is a rational and promising way to regulate the performance of hollow spheres in terms of both functionality and structural robustness,but it remains a big challenge to realize micro-...Multiscale shell structure design is a rational and promising way to regulate the performance of hollow spheres in terms of both functionality and structural robustness,but it remains a big challenge to realize micro-nano engineering of the thin shell while maintaining the low density.In this work,the divisional shell design strategy was adopted to obtain the glass-cobalt-cobalt sulfide composite hollow microspheres(CSH),and an unprecedented stepwise high-temperature chemical reaction-induced aggregation and sub-sequent volume expansion strategy was developed to achieve rational regulation of core-shell structured cobalt-cobalt sulfide building units(BU)assembled on hollow glass microspheres.Special attention has been paid to the sulfidation degree-induced volume control with the underlying mechanism of volume expansion during chemical conversion from metallic cobalt to cobalt sulfide.The electromagnetic prop-erty was found to depend largely on the sulfidation degree due to the volume expansion-induced inter-connecting status regulation among the BU.When evaluated as microwave absorbent,an optimized broad bandwidth of 5.12 GHz and a minimum reflection loss(RLmin)of-45.58 dB of our CSH can be achieved at a thin matching thickness of 1.67 mm and a low filling ratio of 20.04 wt%.In addition to functionality,the divisional shell design also brings the CSH high structural strength(92.36%survival rate at a high hydrostatic pressure of 20 MPa)at low density(0.73 g cm^(-3)).展开更多
The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields.In-situ integrated hierarchical structure const...The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields.In-situ integrated hierarchical structure construction is thought as a promising route to improve the microwave absorption performance of the materials.In the present work,layer-structured Co-metal-organic frameworks(Co-MOFs)precursors were grown in-situ on the surface of carbon fibers with the hydrothermal method.After annealed at 500℃ under Ar atmosphere,a novel multiscale hierarchical composite(Co@C/CF)was obtained with the support of carbon fibers,keeping the flower-like structure.Scanning electron microscope,transmission electron microscope,X-ray diffraction,Raman,and X-ray photoelectron spectroscopy were performed to analyze the microstructure and composition of the hierarchical structure,and the microwave absorption performance of the Co@C/CF composites were investigated.The results showed that the growth of the flower-like structure on the surface of carbon fiber was closely related to the metal-to-ligand ratio.The optimized Co@C/CF flower-like composites achieved the best reflection loss of−55.7 dB in the low frequency band of 6–8 GHz at the thickness of 2.8 mm,with the corresponding effective absorption bandwidth(EAB)of 2.1 GHz.The EAB of 3.24 GHz was achieved in the high frequency range of 12–16 GHz when the thickness was 1.5 mm.The excellent microwave absorption performance was ascribed to the introduction of magnetic components and the construction of the unique structure.The flower-like structure not only balanced the impedance of the fibers themselves,but also extended the propagation path of the microwave and then increased the multiple reflection losses.This work provides a convenient method for the design and development of wave-absorbing composites with in-situ integrated structure.展开更多
Perovskite barium titanate(BaTiO3)demonstrates exceptional dielectric properties as a promising microwave-absorbing(MA)material.Leveraging structural flexibility of perovskites,magnetic components can be incorporated ...Perovskite barium titanate(BaTiO3)demonstrates exceptional dielectric properties as a promising microwave-absorbing(MA)material.Leveraging structural flexibility of perovskites,magnetic components can be incorporated at A/B-sites to enhance MA performance,yet the fundamental disparity in MA mechanisms between A/B-site magnetic doping remains elusive.Herein,nickel-doped BaTiO3 perovskites were systematically synthesized through precise adjustment of the Ba/Ti molar ratio to achieve both A-site(Ni_(x)Ba_(1−x)TiO_(3),N_(x)BTO)and B-site(BaTi_(1−x)Ni_(x)O_(3),BTN^(x)O)substitutions(0≤x≤0.1)via a simple one-step hydrothermal method.Notably,A-site Ni^(2+)substitution in N_(x)BTO induced superior magnetic loss(tanδμ=0.39)attributed to eddy-current dissipation,while B-site doping in BTN^(x)O achieved higher dielectric loss(tanδε=0.49).The N0.1BTO sample exhibited optimal MA performance with a remarkable minimum reflection loss(RLmin)of−44.39 dB and broad effective absorption bandwidth(EAB=8.66 GHz)covering the Ku-band and 67%X-band.Multimodal analysis revealed synergistic interactions among multiple reflection and scattering,multi-polarization relaxation,natural resonance,and eddy currents.In contrast,BTN0.01O demonstrated deeper RLmin(−50.88 dB)but narrower EAB(3.33 GHz)governed by dielectric mechanisms.Structural characterization indicated A-site doping induced lattice distortion,reduced unit-cell volume,and optimized oxygen vacancy distribution,synergistically balancing magneto-dielectric parameters.Conversely,B-site substitution increased oxygen vacancy concentration and carrier mobility while amplifying dielectric fluctuations.The spatial occupation preference of A/B dopants(A-site and B-site)governs lattice symmetry breaking,consequently establishing structure-property relationships and underpinning the material’s tunable dielectric behavior and magnetic phenomena.This work proposes a site-selective doping strategy for designing high-performance perovskite MA materials through magneto-dielectric equilibrium optimization.展开更多
Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle a...Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle and the high oxide dissolution capacity of molten salts,CaO is herein introduced into the affordable molten NaCl-CaCl_(2)-FeO salt to generate CO_(3)^(2-)through an efficient capture of CO_(2).The subsequent coelectrolysis of FeO and CO_(3)^(2-)successfully produces cathodic Fe-encapsulated carbon nanotubes(Fe@CNT)with enhanced energy efficiency(current efficiency of 83.1%for CO_(2)reduction and energy consumption of 22.49 kWh kg^(1)for Fe@CNT generation).The in-situ capture of CO_(2)by O^(2)generated from the electro-deoxidation of FeO bridges the electrolysis of CO_(2)and FeO,rendering the enhanced current efficiency of the co-electrolysis and template-free generation of Fe@CNT.When evaluated as functional materials for electromagnetic wave absorption,the Fe@CNT integrates dielectric loss of CNT and electromagnetic loss from Fe.The Fe well-defined in CNT induces the synergistic loss and further improves the impedance matching,resulting in excellent electromagnetic wave absorption performance.The coelectrolysis establishes a promising strategy for converting CO_(2)into highly functional materials directly from CO_(2)-containing flue gas from steel industrial without dust removal.展开更多
Highly developed electronic information technology has undoubtedly resulted in numerous benefits to the military and public life.However,the resulting electromagnetic wave(EW)pollution cannot be ignored.Therefore,the ...Highly developed electronic information technology has undoubtedly resulted in numerous benefits to the military and public life.However,the resulting electromagnetic wave(EW)pollution cannot be ignored.Therefore,the application of highly efficient EW materials is becoming an important requirement.In this study,magnetic-dielectric heterointerface strategy was applied to construct absorbers with desirable electromagnetic wave properties.A novel CoO/Co nanoparticle anchored to N-doped mesoporous carbon(CoO/Co/N-CMK-3)composites was fabricated by facile precipitation reaction and the electromagnetic characteristics have been well optimized by adjusting pyrolysis temperature.The CoO/Co/N-CMK-3 yielded its highest performance at an annealing temperature of 800℃,with an extended effective absorption bandwidth of 5.83 GHz and unusually low minimum reflection loss of−63.82 dB,even at a thickness of just 1.8 mm and low filler loading(10%).For the excellent microwave absorption property,the advantages of the CoO/Co/N-CMK-3 can be summed up as follows.Firstly,the incorporation of heterointerfaces among N-CMK-3,CoO,and Co introduces abundant polarization centers,triggering various polarization effects and increasing dielectric losses.Secondly,the CoO/Co magnetic component introduced the strong magnetic loss and improved the impedance matching capability of CoO/Co/N-CMK-3.Thirdly,the extraordinary magnetic-dielectric behavior is supported by multiple magnetic coupling networks and enriched air-material heterointerfaces,boosted the magnetoelectric cooperative loss for further optimizing the electromagnetic dissipation and broadening the effective absorption frequency band.Moreover,the CST simulation results validate the impressive operational bandwidth and reflection loss characteristics of the obtained absorbers.This study demonstrates a novel heterointerface engineering strategy for designing lightweight,wide-band,and high-performance EW absorbers.展开更多
Multifunctional carbon aerogels have garnered significant attention due to their promising applications in thermal insulation and electromagnetic wave(EMW)absorption.In this study,MIL-88C/CuCo_(2)S_(4) composite powde...Multifunctional carbon aerogels have garnered significant attention due to their promising applications in thermal insulation and electromagnetic wave(EMW)absorption.In this study,MIL-88C/CuCo_(2)S_(4) composite powders were self-assembled and anchored onto the aerogel framework,followed by the deposition of carbon nanotubes(CNTs)via catalytic chemical vapor deposition,yielding MIL-88C/CuCo_(2)S_(4)-derived bamboo-like CNTs/carbon nanofiber aerogels(FCC@CC series).By modulating component loading ratios,the formation of a three-dimensional conduction network,the presence of heterogeneous interfaces,enhanced magnetic loss,and engineered defects synergistically optimized dielectric and magnetic loss.This adjustment improved the impedance matching of the composite carbon aerogel,resulting in exceptional EMW absorption performance.The FCC@CC2 sample achieved a minimum reflection loss of−71.15 dB and an effective absorption bandwidth of 6.10 GHz.CST simulations further demonstrated the practical applicability,showing a maximum radar cross-section reduction of 34.92 dB·m2.Power loss density and electric field distribution analyses corroborated the superior electromagnetic attenuation capabilities of the FCC@CC.This work establishes a methodology for developing lightweight multifunctional aerogels with pressure resistance,thermal insulation,and infrared stealth properties,providing a novel strategy for the fabrication of microwave absorbers for use under complex conditions.展开更多
The construction of carbon nanocoil(CNC)-based chiral-dielectric-magnetic trinity composites is considered as a promising approach to achieve excellent low-frequency microwave absorption.However,it is still challengin...The construction of carbon nanocoil(CNC)-based chiral-dielectric-magnetic trinity composites is considered as a promising approach to achieve excellent low-frequency microwave absorption.However,it is still challenging to further enhance the low frequency microwave absorption and elucidate the related loss mechanisms.Herein,the chiral CNCs are first synthesized on a threedimensional(3D)carbon foam and then combined with the FeNi/NiFe_(2)O_(4) nanoparticles to form a novel chiral-dielectric-magnetic trinity foam.The 3D porous CNC-carbon foam network provides excellent impedance matching and strong conduction loss.The formation of the FeNi-carbon interfaces induces interfacial polarization loss,which is confirmed by the density functional theory calculations.Further permeability analysis and the micromagnetic simulation indicate that the nanoscale chiral magnetic heterostructures achieve magnetic pinning and coupling effects,which enhance the magnetic anisotropy and magnetic loss capability.Owing to the synergistic effect between dielectricity,chirality,and magnetism,the trinity composite foam exhibits excellent microwave absorption performance with an ultrabroad effective absorption bandwidth(EAB)of 14 GHz and a minimum reflection of loss less than-50 dB.More importantly,the C-band EAB of the foam is extended to 4 GHz,achieving the full C-band coverage.This study provides further guidelines for the microstructure design of the chiral-dielectric-magnetic trinity composites to achieve broadband microwave absorption.展开更多
To address the severe electromagnetic(EM)pollution and thermal exhaustion issues in modern electronics,C@Mn_(x)O_(y) foams were first reported as an advanced multifunctional filler with superior microwave absorption,R...To address the severe electromagnetic(EM)pollution and thermal exhaustion issues in modern electronics,C@Mn_(x)O_(y) foams were first reported as an advanced multifunctional filler with superior microwave absorption,Radar wave stealth,and thermal dissipation.They were synthesized using a simple one-step annealing route,in which PVP and in-situ generated gas bubbles play a crucial role in the foam formation.Our results show that the C@Mn_(x)O_(y) foams possess excellent electrical insulation and a large thermal conductivity of 3.58 W(m K)^(–1) at a low load of 5 wt.%.Also,they exhibit prominent microwave absorption capabilities(MWACs)with a strong absorption(–46.03 dB)and a wide bandwidth(11.04 GHz)in a low load(30 wt.%).When they are then used as a patch,the wideband Radar cross-section can be effectively reduced by up to 41.34 dB m^(2).This performance outperforms most other heterostructures.Furthermore,the mechanism of dielectric loss and thermal transfer at the atomic level is revealed by the First-principle calculations of the density of states(DOS)and the phonon density of states(PDOS).The combination of C,MnO,and Mn_(3)O_(4) disrupts local microstructure symmetry and induces extra electrical dipoles at the heterointerfaces,benefiting the enhanced MWACs of C@Mn_(x)O_(y) foams along with defect polarization and multiple scattering.Their enhanced TC could be credited to the co-transmission of low phonon-boundary/phonon-defect scattering and multiple-frequency phonons from C,MnO,and Mn_(3)O_(4).Overall,the C@Mn_(x)O_(y) foams are highly promising for application in EM protection,absorption,and thermal management.What is more,this study provides a theoretical guide for designing heterostructures as effective microwave absorbing and thermally conductive materials used in modern electronics.展开更多
The intrinsic high magnetocrystalline anisotropy equivalent field can help the hexaferrites break through Snoek’s limit and increase the resonance frequency.This is advantageous for microwave absorption applications ...The intrinsic high magnetocrystalline anisotropy equivalent field can help the hexaferrites break through Snoek’s limit and increase the resonance frequency.This is advantageous for microwave absorption applications in the mid to low-frequency range of gigahertz.In this study,we prepared Z-type Ba_(3)Co_(1.6−x)Zn_(x)Cu_(0.4)Fe_(24)O_(41)hexaferrites using the sol-gel auto-combustion method.By changing the ratio of Co and Zn ions,the magnetocrystalline anisotropy of ferrite is further ma-nipulated,resulting in significant changes in their magnetic resonance frequency and intensity.Ba_(3)Zn_(1.6)Cu_(0.4)Fe_(24)O_(41)with high-frequency resonance achieved the lowest reflectivity of−72.18 dB at 15.56 GHz,while Ba_(3)Co_(1.5)Zn_(0.1)Cu_(0.4)Fe_(24)O_(41)with stronger loss obtained the widest bandwidth of 4.93 GHz(6.14-11.07).Additionally,we investigated surface wave suppression properties previously overlooked.Ba_(3)Co_(1.5)Zn_(0.1)Cu_(0.4)Fe_(24)O_(41)can achieve a larger attenuation at low frequency under low thickness,which has an excellent effect on reducing backscattering.This work provides a useful reference for the preparation and application of high-performance magnetic-loss materials.展开更多
Developing bifunctional materials with smart discoloration and microwave absorption properties has attracted widespread interest in microwave absorption/shielding,yet it is challenging for reversible discoloration per...Developing bifunctional materials with smart discoloration and microwave absorption properties has attracted widespread interest in microwave absorption/shielding,yet it is challenging for reversible discoloration performance in humid(such as forest)and dry(desert)environments.Herein,we combined catalytic chemical vapor deposition(CCVD)technology and a hydrothermal synthesis method to develop a FeSiB@C@NiBr_(2) atomic-scale double-shell gradient structure with rich interfaces.These nanosheet arrays favor interface polarization,impedance matching,and dipole polarization of the material,thereby optimizing the microwave absorption performance.The optimal reflection loss(RL)value of FeSiB@C@NiBr_(2) reached-59.6 dB at 9.2 GHz,and the effective absorption bandwidth(EAB)reached 7.0 GHz at a thickness of 2.5 mm.Compared with pure FeSiB(RL_(min) of-13.5 dB),the RLmin value of the absorber designed by this method increased by~3 times.The color of NiBr_(2) in the outermost nanosheet arrays changes between yellow and green in the case of water molecule harvesting and loss,respectively.This novel FeSiB@C@NiBr_(2) composite structure material is expected to provide a promising platform for wave-absorbing and smart discoloring materials.展开更多
基金financial support from the National Nature Science Foundation of China(No.52273247)the National Science and Technology Major Project of China(J2019-VI-0017-0132).
文摘Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR cloaking mechanisms and functional integration limitations.Here,we propose a multiscale hierarchical structure design,integrating wrinkled MXene IR shielding layer and flexible Fe_(3)O_(4)@C/PDMS microwave absorption layer.The top wrinkled MXene layer induces the intensive diffuse reflection effect,shielding IR radiation signals while allowing microwave to pass through.Meanwhile,the permeable microwaves are assimilated into the bottom Fe_(3)O_(4)@C/PDMS layer via strong magneto-electric synergy.Through theoretical and experimental optimization,the assembled stealth devices realize a near-perfect stealth capability in both X-band(8–12 GHz)and long-wave infrared(8–14μm)wavelength ranges.Specifically,it delivers a radar cross-section reduction of−20 dB m^(2),a large apparent temperature modulation range(ΔT=70℃),and a low average IR emissivity of 0.35.Additionally,the optimal device demonstrates exceptional curved surface conformability,self-cleaning capability(contact angle≈129°),and abrasion resistance(recovery time≈5 s).This design strategy promotes the development of multispectral stealth technology and reinforces its applicability and durability in complex and hostile environments.
基金support from the National Key Research and Development Program of China(No.2021YFB3701503)the Key Research and Development Program of Ningbo,China(No.2023Z107)+1 种基金the Jiangsu Key R&D program,China(No.BE2019072)the special project of Gansu regional science and technology cooperation,China(No.20JR10 QA579).
文摘Exploring high-efficiency and broadband microwave absorption(MA)materials with corrosion resistance and low cost is ur-gently needed for wide practical applications.Herein,the natural porous attapulgite(ATP)nanorods embedded with TiO_(2)and polyaniline(PANI)nanoparticles are synthesized via heterogeneous precipitation and in-situ polymerization.The obtained PANI-TiO_(2)-ATP one-di-mensional(1D)nanostructures can intertwine into three-dimensional(3D)conductive network,which favors energy dissipation.The min-imum reflection loss(RL_(min))of the PANI-TiO_(2)-ATP coating(20wt%)reaches-49.36 dB at 9.53 GHz,and the effective absorption band-width(EAB)can reach 6.53 GHz with a thickness of 2.1 mm.The excellent MA properties are attributed to interfacial polarization,mul-tiple loss mechanisms,and good impedance matching induced by the synergistic effect of PANI-TiO_(2)nanoparticle shells and ATP nanor-ods.In addition,salt spray and Tafel polarization curve tests reveal that the PANI-TiO_(2)-ATP coating shows outstanding corrosion resist-ance performance.This study provides a low-cost and high-efficiency strategy for constructing 1D nanonetwork composites for MA and corrosion resistance applications using natural porous ATP nanorods as carriers.
基金supported by the National Natural Science Foundation of China(Nos.52373280,52177014 and 52273257).
文摘Exploring efficient microwave absorbing materials(MAMs)has gradually become a hot topic in recent years because it is crucial in both civil and military fields.Metal-organic framework(MOF)has great potential due to its unique composition and bonding mode,which has advantages such as large specific surface area,high porosity,adjustable structure,and designable composition.Herein,MOF-derived MAMs are highlighted based on morphology and structure.The synthesis strategies of MOF-derived MAMs of different dimensions are discussed.On this basis,the structure-activity relationships can be deeply explored through the precise control of material structure and property by atomic engineering.Finally,perspectives are given for the existing problems of MOF-derived MAMs,which will open a new horizon and promote the development of MAMs.
基金supported by the Basic Research Development Program of China(No.JCKY2021607B036)the National Natural Science Foundation of China(No.52275512).
文摘There is an urgent need for the application of broadband Microwave Absorption(MA)structures on the leading edges of aircraft wings,which requires the MA structures to possess both the broadband MA performance and great surface conformability.To meet these requirements,we designed and fabricated a flexible bioinspired meta-structure with ultra-broadband MA,thin thickness and excellent surface conformality.The carbonyl iron powder-carbon nanotubes-polydimethylsiloxane composite was synthesized by physical blending method for fabricating the MA meta-structure.Through geometry-electromagnetic optimal design by heuristic optimization algorithm,the meta-structure mimicking to the nipple photonic nanostructures on the eyes of moth can achieve ultra-broadband MA performance of 35.14 GHz MA bandwidth(reflection loss≤–10 dB),covering 4.86–40.00 GHz,with thickness of only 4.3 mm.Through simple fabrication processes,the meta-structure has been successfully fabricated and bonded on wings’leading edges,exhibiting excellent surface conformability.Furthermore,the designed flexible MA meta-structure possesses significant Radar Cross-Section(RCS)reduction capability,as demonstrated by the RCS analysis of an unmanned aerial vehicle.This flexible ultra-broadband MA meta-structure provides an outstanding candidate to meet the radar stealth requirement of variable curvature structures on aircraft.
基金the financial support provided by Graduate Scientific Research and Innovation Foundation of Chongqing,China(CYB22007,CYS22005)Projects(No.2020CDJXZ001)supported by the Fundamental Research Funds for the Central Universities+2 种基金the Technology Innovation and Application Development Special Project of Chongqing(Z20211350 and Z20211351)Scientific Research Project of Chongqing Ecological Environment Bureau(No.CQEE2022STHBZZ118)Fundamental Research Funds for the Central Universities(Grant No.2024IAIS-QN008)。
文摘Inspired by the remarkable electromagnetic response capabilities of the complex morphologies and subtle microstructures evolved by natural organisms,this paper delves into the research advancements and future application potential of bionic microwave-absorbing materials(BMAMs).It outlines the significance of achieving high-performance microwave-absorbing materials through ingenious microstructural design and judicious composition selection,while emphasizing the innovative strategies offered by bionic manufacturing.Furthermore,this work meticulously analyzes how inspiration can be drawn from the intricate structures of marine organisms,plants,animals,and nonmetallic minerals in nature to devise and develop BMAMs with superior electromagnetic wave absorption properties.Additionally,the paper provides an in-depth exploration of the theoretical underpinnings of BMAMs,particularly the latest breakthroughs in broadband absorption.By incorporating advanced methodologies such as simulation modeling and bionic gradient design,we unravel the scientific principles governing the microwave absorption mechanisms of BMAMs,thereby furnishing a solid theoretical foundation for understanding and optimizing their performance.Ultimately,this review aims to offer valuable insights and inspiration to researchers in related fields,fostering the collective advancement of research on BMAMs.
基金financially supported by the Key Project of Natural Science Research in Colleges and Universities of Anhui Province,China(No.2022AH050816)the Open Research Grant of Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining(Nos.EC2023013 and EC2022018)+1 种基金the National Natural Science Foundation of China(No.52200139)the Introduction of Talent in Anhui University of Science and Technology,China(Nos.2021yjrc18 and 2023yjrc79)。
文摘Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary society.In this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal method.Various mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these composites.Consequently,compared with pure residual carbon materials,this composite offers superior capabilities in microwave absorption.At 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 mm.Moreover,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of 1.18mm.This study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.
基金support from the National Natural Science Foundation of China(U21A2093)Shaanxi Province Key Research and Development Plan Project(2023-YBGY-461)+4 种基金Platform of Science and Technology and Talent Team Plan of Guizhou province(GCC[2023]007)Guizhou Provincial Basic Research Program(Natural Science)(No.ZK[2025]Key 086)Fok Ying Tung Education Foundation(171095)financial support,Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(CX2024094)。
文摘The previous studies mainly focused on improving microwave absorbing(MA)performances of MA materials.Even so,these designed MA materials were very difficult to be employed in complex and changing environments owing to their single-functionalities.Herein,a combined Prussian blue analogues derived and catalytical chemical vapor deposition strategy was proposed to produce hierarchical cubic sea urchin-like yolk–shell CoNi@Ndoped carbon(NC)-CoNi@carbon nanotubes(CNTs)mixed-dimensional multicomponent nanocomposites(MCNCs),which were composed of zerodimensional CoNi nanoparticles,three-dimensional NC nanocubes and onedimensional CNTs.Because of good impedance matching and attenuation characteristics,the designed CoNi@NC-CoNi@CNTs mixed-dimensional MCNCs exhibited excellent MA performances,which achieved a minimum reflection loss(RL_(min))of−71.70 dB at 2.78 mm and Radar Cross section value of−53.23 dB m^(2).More importantly,the acquired results demonstrated that CoNi@NC-CoNi@CNTs MCNCs presented excellent photothermal,antimicrobial and anti-corrosion properties owing to their hierarchical cubic sea urchin-like yolk–shell structure,highlighting their potential multifunctional applications.It could be seen that this finding not only presented a generalizable route to produce hierarchical cubic sea urchin-like yolk–shell magnetic NC-CNTs-based mixed-dimensional MCNCs,but also provided an effective strategy to develop multifunctional MCNCs and improve their environmental adaptabilities.
基金supported by the National Natural Science Foundation of China(Nos.52202105,51772177,52231007,12327804)the Project Funded by China Postdoctoral Science Foundation(No.2021M702056).
文摘Carbon materials have made significant progress in the field of microwave absorption(MA),but achieving wide effective absorption bandwidth(EAB)at low filler content still remains a great challenge.In this work,we design multi-shell bowl-like mesoporous carbon microspheres(MBMCs)by a facile hard template method for efficient MA.It is demonstrated that the spacing between inner and outer shell and second shell thickness play a vital role on the configuration of carbon microspheres.By controlling the second addition of silica template,the microstructure of carbon microsphere evolves from spherical to bowl shape geometry.Expanded shell spacing is beneficial for forming bowl-like microsphere.The dielectric loss and MA properties are highly associated with the configuration of MBMCs.Well-proportioned MBMCs with appropriate shell spacing present wide EAB of 7.3 GHz under a low filling ratio of 12 wt.%.This work paves a new way to broaden EAB and lower filling content of carbon materials via asymmetric multilayer microstructure design.
基金financially supported by the National Natural Science Youth Foundation of China(No.52402086)Natural Science Foundation of Shandong Province(No.ZR2023QE002)+6 种基金Youth Innovation Team Program in Colleges of Shandong Province(No.2023KJ144)Shandong Province Science and Technology Small and Medium-sized Enterprises Innovation Capability Improvement Project(No.2022TSGC1158)China Postdoctoral Science Foundation(No.2021M691963)Key Research and Development Program of Shandong Province of China(No.2020JMRH0503)the Fundamental Research Funds for the Central Universities(No.HIT.OCEF.2021003)National Natural Science Foundation of China(No.52272067)Doctoral Scientific Research Start-up Foundation from Shandong University of Technology(No.4041/419008)
文摘Lightweight materials with wide absorption capabilities,particularly in the C-band,have remained a challenge thus far.Recent research has indicated that effective absorption networks built by microfiber polarization loss can be a significant factor in increasing the effective absorption bandwidth(EAB).In this study,leaf vein-like carbon(LVC)was synthesized using an in situ blowing strategy.Taking inspiration from photosynthesis energy conversion mechanisms,a leaf veins-like hierarchical structure was created to establish an effective impedance-matching network and generate a high-density polarization region through leaf vein microfibers.This enhanced polarization relaxation effectively broadens the EAB of the LVC.At a low filling ratio of 6.3 wt%,the EAB of the LVC covers 80%of the C-band,as well as100%of the X-band and Ku-band.Achieving such a wide EAB in the C-band,especially in the multi-band context,relies on impedance matching and optimized polarization relaxation.This work demonstrates the crucial role of leaf vein micronetwork engineering in enhancing the C-band absorption properties of carbon-based materials,thus providing a viable reference for the development of lightweight,broadband,and highly absorptive materials for electromagnetic applications.
基金financially supported by the National Natural Science Foundation of China(Nos.52402354,62174016 and 12374394)China Postdoctoral Science Foundation(Nos.2023M740471)the Natural Science Foundation of Jiangsu Higher Education Institutions(Nos.24KJB430002)。
文摘Heterojunction and morphology control assume a significant part in adjusting the intrinsic electromagnetic properties of absorbers to acquire outstanding microwave absorption(MA)performance,but this still faces huge challenges.Herein,FeS_(2)/C/MoS_(2)composite with core–shell structure was successfully designed and prepared via a multi-interface engineering.MoS_(2)nanosheets with 1T and 2H phases are coated on the outside of FeS_(2)/C to form a porous interconnected structure that can optimize the impedance matching characteristics and strengthen the interfacial polarization loss capacity.Remarkably,as-fabricated FCM-3 harvests a broad effective absorption bandwidth(EAB)of 5.12 GHz and a minimum reflection loss(RL_(min))value of-45.1 d B.Meanwhile,FCM-3 can accomplish a greatest radar cross section(RCS)reduction value of 18.52 d B m^(2)when the detection angle is 0°.Thus,the convenient computer simulation technology(CST)simulations and encouraging accomplishments provide a novel avenue for the further development of efficient and lightweight MA materials.
基金supported by the National Natural Science Foundation of China(project No 51872298)the fund of the State Key Laboratory of Technologies in Space Cryogenic Pro-pellants(project No SKLTSCP202202)the Strategic Priority Re-search Program of the Chinese Academy of Science(project No XDA22010202).
文摘Multiscale shell structure design is a rational and promising way to regulate the performance of hollow spheres in terms of both functionality and structural robustness,but it remains a big challenge to realize micro-nano engineering of the thin shell while maintaining the low density.In this work,the divisional shell design strategy was adopted to obtain the glass-cobalt-cobalt sulfide composite hollow microspheres(CSH),and an unprecedented stepwise high-temperature chemical reaction-induced aggregation and sub-sequent volume expansion strategy was developed to achieve rational regulation of core-shell structured cobalt-cobalt sulfide building units(BU)assembled on hollow glass microspheres.Special attention has been paid to the sulfidation degree-induced volume control with the underlying mechanism of volume expansion during chemical conversion from metallic cobalt to cobalt sulfide.The electromagnetic prop-erty was found to depend largely on the sulfidation degree due to the volume expansion-induced inter-connecting status regulation among the BU.When evaluated as microwave absorbent,an optimized broad bandwidth of 5.12 GHz and a minimum reflection loss(RLmin)of-45.58 dB of our CSH can be achieved at a thin matching thickness of 1.67 mm and a low filling ratio of 20.04 wt%.In addition to functionality,the divisional shell design also brings the CSH high structural strength(92.36%survival rate at a high hydrostatic pressure of 20 MPa)at low density(0.73 g cm^(-3)).
基金financially supported by the National Natural Science of Foundation of China(No.52371097)the Shenyang Unveiling and Leading Project,China(No.22-301-1-01)。
文摘The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields.In-situ integrated hierarchical structure construction is thought as a promising route to improve the microwave absorption performance of the materials.In the present work,layer-structured Co-metal-organic frameworks(Co-MOFs)precursors were grown in-situ on the surface of carbon fibers with the hydrothermal method.After annealed at 500℃ under Ar atmosphere,a novel multiscale hierarchical composite(Co@C/CF)was obtained with the support of carbon fibers,keeping the flower-like structure.Scanning electron microscope,transmission electron microscope,X-ray diffraction,Raman,and X-ray photoelectron spectroscopy were performed to analyze the microstructure and composition of the hierarchical structure,and the microwave absorption performance of the Co@C/CF composites were investigated.The results showed that the growth of the flower-like structure on the surface of carbon fiber was closely related to the metal-to-ligand ratio.The optimized Co@C/CF flower-like composites achieved the best reflection loss of−55.7 dB in the low frequency band of 6–8 GHz at the thickness of 2.8 mm,with the corresponding effective absorption bandwidth(EAB)of 2.1 GHz.The EAB of 3.24 GHz was achieved in the high frequency range of 12–16 GHz when the thickness was 1.5 mm.The excellent microwave absorption performance was ascribed to the introduction of magnetic components and the construction of the unique structure.The flower-like structure not only balanced the impedance of the fibers themselves,but also extended the propagation path of the microwave and then increased the multiple reflection losses.This work provides a convenient method for the design and development of wave-absorbing composites with in-situ integrated structure.
基金the Central Universities(Nos.SWU-KF25028 and SWU-XDJH202314)Natural Science Foundation Project of Chongqing(No.cstc2024ycjh-bgzxm0005)the Opening Project of State Key Laboratory of Solid Lubrication(No.LSL2416)for financial support.We also thank Analytical&Testing Center in Southwest University for SEM test.
文摘Perovskite barium titanate(BaTiO3)demonstrates exceptional dielectric properties as a promising microwave-absorbing(MA)material.Leveraging structural flexibility of perovskites,magnetic components can be incorporated at A/B-sites to enhance MA performance,yet the fundamental disparity in MA mechanisms between A/B-site magnetic doping remains elusive.Herein,nickel-doped BaTiO3 perovskites were systematically synthesized through precise adjustment of the Ba/Ti molar ratio to achieve both A-site(Ni_(x)Ba_(1−x)TiO_(3),N_(x)BTO)and B-site(BaTi_(1−x)Ni_(x)O_(3),BTN^(x)O)substitutions(0≤x≤0.1)via a simple one-step hydrothermal method.Notably,A-site Ni^(2+)substitution in N_(x)BTO induced superior magnetic loss(tanδμ=0.39)attributed to eddy-current dissipation,while B-site doping in BTN^(x)O achieved higher dielectric loss(tanδε=0.49).The N0.1BTO sample exhibited optimal MA performance with a remarkable minimum reflection loss(RLmin)of−44.39 dB and broad effective absorption bandwidth(EAB=8.66 GHz)covering the Ku-band and 67%X-band.Multimodal analysis revealed synergistic interactions among multiple reflection and scattering,multi-polarization relaxation,natural resonance,and eddy currents.In contrast,BTN0.01O demonstrated deeper RLmin(−50.88 dB)but narrower EAB(3.33 GHz)governed by dielectric mechanisms.Structural characterization indicated A-site doping induced lattice distortion,reduced unit-cell volume,and optimized oxygen vacancy distribution,synergistically balancing magneto-dielectric parameters.Conversely,B-site substitution increased oxygen vacancy concentration and carrier mobility while amplifying dielectric fluctuations.The spatial occupation preference of A/B dopants(A-site and B-site)governs lattice symmetry breaking,consequently establishing structure-property relationships and underpinning the material’s tunable dielectric behavior and magnetic phenomena.This work proposes a site-selective doping strategy for designing high-performance perovskite MA materials through magneto-dielectric equilibrium optimization.
基金supported by the National Key R&D Program of China(2023YFA1508001)the National Natural Science Foundation of China(22272120 and U2202251)+2 种基金the Fundamental Research Funds for the Central Universities(2042022kf1174)the Hainan Province Science and Technology Special Fund(ZDYF2023SHFZ120 and ZDYF2021SHFZ058)the Research Foundation of Marine Science and Technology Collaborative Innovation Center of Hainan University(XTCX2022HYB01)。
文摘Direct utilization of co-existed ferrous oxide(FeO)dust in CO_(2)flue gas from the steel industry to product value-added materials is yet to be established.Inspired by the form of CaO-CaCO_(3)as natural carbon cycle and the high oxide dissolution capacity of molten salts,CaO is herein introduced into the affordable molten NaCl-CaCl_(2)-FeO salt to generate CO_(3)^(2-)through an efficient capture of CO_(2).The subsequent coelectrolysis of FeO and CO_(3)^(2-)successfully produces cathodic Fe-encapsulated carbon nanotubes(Fe@CNT)with enhanced energy efficiency(current efficiency of 83.1%for CO_(2)reduction and energy consumption of 22.49 kWh kg^(1)for Fe@CNT generation).The in-situ capture of CO_(2)by O^(2)generated from the electro-deoxidation of FeO bridges the electrolysis of CO_(2)and FeO,rendering the enhanced current efficiency of the co-electrolysis and template-free generation of Fe@CNT.When evaluated as functional materials for electromagnetic wave absorption,the Fe@CNT integrates dielectric loss of CNT and electromagnetic loss from Fe.The Fe well-defined in CNT induces the synergistic loss and further improves the impedance matching,resulting in excellent electromagnetic wave absorption performance.The coelectrolysis establishes a promising strategy for converting CO_(2)into highly functional materials directly from CO_(2)-containing flue gas from steel industrial without dust removal.
基金financially supported by National Key Research and Development Program of China(Nos.2022YFB3807100 and 2022YFB3807101)National Science Fund for Distinguished Young Scholars(No.52025034)+3 种基金National Natural Science Foundation of China(No.22205182)Guangdong Basic and Applied Basic Re-search Foundation(No.2024A1515011516)China Postdoctoral Science Foundation(Nos.2022M722594 and 2024T171710)financially supported by Innovation Team of Shaanxi Sanqin Scholars.
文摘Highly developed electronic information technology has undoubtedly resulted in numerous benefits to the military and public life.However,the resulting electromagnetic wave(EW)pollution cannot be ignored.Therefore,the application of highly efficient EW materials is becoming an important requirement.In this study,magnetic-dielectric heterointerface strategy was applied to construct absorbers with desirable electromagnetic wave properties.A novel CoO/Co nanoparticle anchored to N-doped mesoporous carbon(CoO/Co/N-CMK-3)composites was fabricated by facile precipitation reaction and the electromagnetic characteristics have been well optimized by adjusting pyrolysis temperature.The CoO/Co/N-CMK-3 yielded its highest performance at an annealing temperature of 800℃,with an extended effective absorption bandwidth of 5.83 GHz and unusually low minimum reflection loss of−63.82 dB,even at a thickness of just 1.8 mm and low filler loading(10%).For the excellent microwave absorption property,the advantages of the CoO/Co/N-CMK-3 can be summed up as follows.Firstly,the incorporation of heterointerfaces among N-CMK-3,CoO,and Co introduces abundant polarization centers,triggering various polarization effects and increasing dielectric losses.Secondly,the CoO/Co magnetic component introduced the strong magnetic loss and improved the impedance matching capability of CoO/Co/N-CMK-3.Thirdly,the extraordinary magnetic-dielectric behavior is supported by multiple magnetic coupling networks and enriched air-material heterointerfaces,boosted the magnetoelectric cooperative loss for further optimizing the electromagnetic dissipation and broadening the effective absorption frequency band.Moreover,the CST simulation results validate the impressive operational bandwidth and reflection loss characteristics of the obtained absorbers.This study demonstrates a novel heterointerface engineering strategy for designing lightweight,wide-band,and high-performance EW absorbers.
基金supported by the Natural Science Foundation of Shandong Province(Nos.2024TSGC0550,2023TSGC0545,and 2023TATSGC025)Key Technology Research and Development Program of Shandong Province(No.2021ZLGX01)The authors would like to thank Conghua Qi from Shiyanjia Lab(www.shiyanjia.com)for TEM test.The scientific calculations in this paper have been done on the HPC Cloud Platform of Shandong University.
文摘Multifunctional carbon aerogels have garnered significant attention due to their promising applications in thermal insulation and electromagnetic wave(EMW)absorption.In this study,MIL-88C/CuCo_(2)S_(4) composite powders were self-assembled and anchored onto the aerogel framework,followed by the deposition of carbon nanotubes(CNTs)via catalytic chemical vapor deposition,yielding MIL-88C/CuCo_(2)S_(4)-derived bamboo-like CNTs/carbon nanofiber aerogels(FCC@CC series).By modulating component loading ratios,the formation of a three-dimensional conduction network,the presence of heterogeneous interfaces,enhanced magnetic loss,and engineered defects synergistically optimized dielectric and magnetic loss.This adjustment improved the impedance matching of the composite carbon aerogel,resulting in exceptional EMW absorption performance.The FCC@CC2 sample achieved a minimum reflection loss of−71.15 dB and an effective absorption bandwidth of 6.10 GHz.CST simulations further demonstrated the practical applicability,showing a maximum radar cross-section reduction of 34.92 dB·m2.Power loss density and electric field distribution analyses corroborated the superior electromagnetic attenuation capabilities of the FCC@CC.This work establishes a methodology for developing lightweight multifunctional aerogels with pressure resistance,thermal insulation,and infrared stealth properties,providing a novel strategy for the fabrication of microwave absorbers for use under complex conditions.
基金supported by the National Natural Science Foundation of China[Grant Nos.52272288 and 51972039]the China Postdoctoral Science Foundation[No.2021M700658].
文摘The construction of carbon nanocoil(CNC)-based chiral-dielectric-magnetic trinity composites is considered as a promising approach to achieve excellent low-frequency microwave absorption.However,it is still challenging to further enhance the low frequency microwave absorption and elucidate the related loss mechanisms.Herein,the chiral CNCs are first synthesized on a threedimensional(3D)carbon foam and then combined with the FeNi/NiFe_(2)O_(4) nanoparticles to form a novel chiral-dielectric-magnetic trinity foam.The 3D porous CNC-carbon foam network provides excellent impedance matching and strong conduction loss.The formation of the FeNi-carbon interfaces induces interfacial polarization loss,which is confirmed by the density functional theory calculations.Further permeability analysis and the micromagnetic simulation indicate that the nanoscale chiral magnetic heterostructures achieve magnetic pinning and coupling effects,which enhance the magnetic anisotropy and magnetic loss capability.Owing to the synergistic effect between dielectricity,chirality,and magnetism,the trinity composite foam exhibits excellent microwave absorption performance with an ultrabroad effective absorption bandwidth(EAB)of 14 GHz and a minimum reflection of loss less than-50 dB.More importantly,the C-band EAB of the foam is extended to 4 GHz,achieving the full C-band coverage.This study provides further guidelines for the microstructure design of the chiral-dielectric-magnetic trinity composites to achieve broadband microwave absorption.
基金financially supported by the National Natural Science Foundation of China(No.52073260)the Zhejiang Provincial Natural Science Foundation of China(Nos.LGG21E020002 and LZ24E020004)the Major industrial projects of Jinhua City(No.2024A11011).
文摘To address the severe electromagnetic(EM)pollution and thermal exhaustion issues in modern electronics,C@Mn_(x)O_(y) foams were first reported as an advanced multifunctional filler with superior microwave absorption,Radar wave stealth,and thermal dissipation.They were synthesized using a simple one-step annealing route,in which PVP and in-situ generated gas bubbles play a crucial role in the foam formation.Our results show that the C@Mn_(x)O_(y) foams possess excellent electrical insulation and a large thermal conductivity of 3.58 W(m K)^(–1) at a low load of 5 wt.%.Also,they exhibit prominent microwave absorption capabilities(MWACs)with a strong absorption(–46.03 dB)and a wide bandwidth(11.04 GHz)in a low load(30 wt.%).When they are then used as a patch,the wideband Radar cross-section can be effectively reduced by up to 41.34 dB m^(2).This performance outperforms most other heterostructures.Furthermore,the mechanism of dielectric loss and thermal transfer at the atomic level is revealed by the First-principle calculations of the density of states(DOS)and the phonon density of states(PDOS).The combination of C,MnO,and Mn_(3)O_(4) disrupts local microstructure symmetry and induces extra electrical dipoles at the heterointerfaces,benefiting the enhanced MWACs of C@Mn_(x)O_(y) foams along with defect polarization and multiple scattering.Their enhanced TC could be credited to the co-transmission of low phonon-boundary/phonon-defect scattering and multiple-frequency phonons from C,MnO,and Mn_(3)O_(4).Overall,the C@Mn_(x)O_(y) foams are highly promising for application in EM protection,absorption,and thermal management.What is more,this study provides a theoretical guide for designing heterostructures as effective microwave absorbing and thermally conductive materials used in modern electronics.
基金supported by the National Natural Science Foundation of China(No.62371222)the Defense Industrial Technology Development Program(No.JCKY2023605C002)thePriority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)and the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory(No.ZHD202305).
文摘The intrinsic high magnetocrystalline anisotropy equivalent field can help the hexaferrites break through Snoek’s limit and increase the resonance frequency.This is advantageous for microwave absorption applications in the mid to low-frequency range of gigahertz.In this study,we prepared Z-type Ba_(3)Co_(1.6−x)Zn_(x)Cu_(0.4)Fe_(24)O_(41)hexaferrites using the sol-gel auto-combustion method.By changing the ratio of Co and Zn ions,the magnetocrystalline anisotropy of ferrite is further ma-nipulated,resulting in significant changes in their magnetic resonance frequency and intensity.Ba_(3)Zn_(1.6)Cu_(0.4)Fe_(24)O_(41)with high-frequency resonance achieved the lowest reflectivity of−72.18 dB at 15.56 GHz,while Ba_(3)Co_(1.5)Zn_(0.1)Cu_(0.4)Fe_(24)O_(41)with stronger loss obtained the widest bandwidth of 4.93 GHz(6.14-11.07).Additionally,we investigated surface wave suppression properties previously overlooked.Ba_(3)Co_(1.5)Zn_(0.1)Cu_(0.4)Fe_(24)O_(41)can achieve a larger attenuation at low frequency under low thickness,which has an excellent effect on reducing backscattering.This work provides a useful reference for the preparation and application of high-performance magnetic-loss materials.
基金supported by the National Natural Science Foundation of China(Nos.51972045 and 52202368)the Fundamental Research Funds for the Chinese Central Universities,China(No.ZYGX2019J025)Sichuan Science and Technology Program(No.2021YFG0373).
文摘Developing bifunctional materials with smart discoloration and microwave absorption properties has attracted widespread interest in microwave absorption/shielding,yet it is challenging for reversible discoloration performance in humid(such as forest)and dry(desert)environments.Herein,we combined catalytic chemical vapor deposition(CCVD)technology and a hydrothermal synthesis method to develop a FeSiB@C@NiBr_(2) atomic-scale double-shell gradient structure with rich interfaces.These nanosheet arrays favor interface polarization,impedance matching,and dipole polarization of the material,thereby optimizing the microwave absorption performance.The optimal reflection loss(RL)value of FeSiB@C@NiBr_(2) reached-59.6 dB at 9.2 GHz,and the effective absorption bandwidth(EAB)reached 7.0 GHz at a thickness of 2.5 mm.Compared with pure FeSiB(RL_(min) of-13.5 dB),the RLmin value of the absorber designed by this method increased by~3 times.The color of NiBr_(2) in the outermost nanosheet arrays changes between yellow and green in the case of water molecule harvesting and loss,respectively.This novel FeSiB@C@NiBr_(2) composite structure material is expected to provide a promising platform for wave-absorbing and smart discoloring materials.
