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
The rational construction of lightweight composites with multiple heterogeneous interfaces represents an effective strategy for achieving efficient electromagnetic wave(EMW)absorption.However,the impact of multiple he...The rational construction of lightweight composites with multiple heterogeneous interfaces represents an effective strategy for achieving efficient electromagnetic wave(EMW)absorption.However,the impact of multiple heterogeneous interfaces on electromagnetic performance still needs further exploration.Herein,reduced graphene oxide(rGO)@Ni-FeCo layered hydroxide(LDH)derivatives with multiple heterostructures were synthesized by a series of processes including electrostatic self-assembly,freeze-drying and thermal annealing.The conductive network in rGO and the cavities inside LDH facilitate electron migration and effectively prolong the propagation path of EMW,thereby enhancing conductivity loss.The abundant heterogeneous interfaces between carbon components and metal nanoparticles induce interfacial polarization.In addition,the catalytic activity differences of different metal particles generate different dielectric electromagnetic interfaces,which further promote interfacial polarization.The natural and exchange resonance formed by magnetic particles under a magnetic field provides magnetic losses.Therefore,the successful construction of multiple heterogeneous interfaces effectively enhances the conductivity loss and polarization loss.With a thickness of only 1.4 mm,the composite achieves a minimum reflection loss of-51.8 dB and an effective absorption bandwidth of 4.5 GHz.This work provides an effective strategy for achieving thin thickness and efficient EMW absorption through precise structural design and multi-component construction of absorbers.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
One-dimensional(1D)carbon nanofibers with unique three-dimensional(3D)network structure and high electrical conductivity are an important microwave absorbing material.However,due to poor impedance matching and single ...One-dimensional(1D)carbon nanofibers with unique three-dimensional(3D)network structure and high electrical conductivity are an important microwave absorbing material.However,due to poor impedance matching and single loss mechanism,its effective absorption bandwidth(EAB)is limited.Therefore,in this work,a porous hollow carbon fiber is designed using coaxial electrostatic spinning,and the magnetic component CoFe alloy is introduced during high temperature sintering to prepare porous CoFe hollow carbon fiber composite(CF@HCF).Its unique 1D nanostructure and 3D interconnected structure facili-tates multiple reflection losses of electromagnetic waves within the material.In addition,the presence of porous and hollow structures increases heterogeneous interfaces and surface area.The introduction of magnetic components on carbon fibers not only increases the magnetic loss,but also forms a variety of heterogeneous interfaces.In addition,the porous hollow structure improves the spatial efficiency and porosity of the composites,thus optimizing impedance matching.The results indicate that,at a filler ra-tio of 25 wt%,the EAB reaches 7.04 GHz,with a minimum reflection loss(RL_(min))of−50.04 dB under a matching thickness of 2.4 mm.In addition,to extend practical applications,CF@HCF composite membrane with excellent flexibility was prepared using PDMS encapsulation technology,and the sample also shows an average electromagnetic shielding performance of>30 dB.Besides,the radar cross section(RCS)val-ues are below−10 dB m²,demonstrating the material’s significant radar wave attenuation capability and practical application potential.This work provides some perspectives on the preparation of hollow carbon fiber magnetic powder composites,and lays the foundation for the application of magnetic carbon-based composites.展开更多
TiAl/Ti_(2)AlNb intermetallic-intermetallic laminated(IIL)composites featuring brittle/ductile heterogeneous interfaces were fabricated through vacuum hot-pack rolling.The microstructures and the phase transfor-mation...TiAl/Ti_(2)AlNb intermetallic-intermetallic laminated(IIL)composites featuring brittle/ductile heterogeneous interfaces were fabricated through vacuum hot-pack rolling.The microstructures and the phase transfor-mation behaviors of the interfaces of the IIL composites before and after annealing at 900°C/6 h were in-vestigated.The heterogeneous interfaces are composed of four distinct regions,individually I(β_(o)+γ+α_(2)),II(β_(o)/B_(2)+ω)(brittle part),III(O lath),and IV(equiaxed O)(ductile part)regions from TiAl to Ti_(2)AlNb side.Notably,after annealing,an equiaxed O band approximately 50μm wide was observed in region IV of the interface.In addition,a significant microhardness variation was observed between regions II and IV of the interface,where region II exhibited higher hardness compared to the TiAl alloy,and region IV displayed lower hardness than the Ti_(2)AlNb alloy.The enhanced fracture toughness of the IIL composites,three times that of the TiAl base alloy,is attributed to the formation of the brittle/ductile heterogeneous interfaces and the layered design incorporating the Ti_(2)AlNb alloy.The corresponding toughening mech-anism was further discussed.The brittle II region plays a role in increasing crack branching,while the ductile IV region inhibits the propagation of microcracks and prevents the formation of main cracks.This work highlights the crucial role of the brittle/ductile heterogeneous interface in the toughening of lam-inated composites.Furthermore,the discovery of the O band provides novel insights into the design of TiAl/Ti_(2)AlNb heterostructures.展开更多
Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion batteries.However,due to low inherent conductivity and significant volume expansion,the electro...Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion batteries.However,due to low inherent conductivity and significant volume expansion,the electrochemical performance is greatly limited.In this study,a nickel/manganese sulfide material(Ni_(0.96)S_(x)/MnS_(y)-NC)with adjustable sulfur vacancies and heterogeneous hollow spheres was prepared using a simple method.The introduction of a concentration-adjustable sulfur vacancy enables the generation of a heterogeneous interface between bimetallic sulfide and sulfur vacancies.This interface collectively creates an internal electric field,improving the mobility of electrons and ions,increasing the number of electrochemically active sites,and further optimizing the performance of Na~+storage.The direction of electron flow is confirmed by Density functional theory(DFT)calculations.The hollow nano-spherical material provides a buffer for expansion,facilitating rapid transfer kinetics.Our innovative discovery involves the interaction between the ether-based electrolyte and copper foil,leading to the formation of Cu_9S_5,which grafts the active material and copper current collector,reinforcing mechanical supporting.This results in a new heterostructure of Cu_9S_5 with Ni_(0.96)S_(x)/MnS_(y),contributing to the stabilization of structural integrity for long-cycle performance.Therefore,Ni_(0.96)S_(x)/MnS_(y)-NC exhibits excellent electrochemical properties following our modification route.Regarding stability performance,Ni0_(.96)S_(x)/MnS_(y)-NC demonstrates an average decay rate of 0.00944%after 10,000 cycles at an extremely high current density of 10000 mA g^(-1),A full cell with a high capacity of 304.2 mA h g^(-1)was also successfully assembled by using Na_(3)V_(2)(PO_(4))_(3)/C as the cathode.This study explores a novel strategy for interface/vacancy co-modification in the fabrication of high-performance sodium-ion batteries electrode.展开更多
In view of the current serious electromagnetic pollution problem,it is urgent to study efficient electromagnetic wave absorbing materials.The construction of multiphase inhomogeneous interfaces is an effective means,e...In view of the current serious electromagnetic pollution problem,it is urgent to study efficient electromagnetic wave absorbing materials.The construction of multiphase inhomogeneous interfaces is an effective means,especially for the fine design of multicomponent materials.In this study,multiphase composites with tunable heterogeneous interfaces were prepared by hydrothermal synthesis,carbon coating and high-temperature annealing processes.Multiple component composites constructed rich heterogeneous interfaces,which exhibited strong interfacial polarization effects and effectively improved the absorption efficiency of electromagnetic wave(EMW).The fine tuning of the heterogeneous interfaces is achieved through component adjustment,which enhances the charge carrier transport efficiency and the polarization loss capability.Ultimately,the multiphase VS_(2)@C@WS_(2)composites obtained excellent EMW absorption performance,with the minimum reflection loss and the maximum effective absorption bandwidth of-66.35 dB and 5.12 GHz,respectively.In this work,the controllable construction of heterogeneous interfaces is achieved through the tuning of components,which provides a valuable method for optimizing the polarization loss.展开更多
Optimizing the oxygen reduction reaction(ORR)kinetics requires precise control of intermediate adsorption at active sites,which can be achieved through orbital engineering by regulating the electronic structure.This s...Optimizing the oxygen reduction reaction(ORR)kinetics requires precise control of intermediate adsorption at active sites,which can be achieved through orbital engineering by regulating the electronic structure.This study addresses the challenge by exploring how modulation of the 3d-orbital electronic structure of FeN_(4) active sites influences ORR electrocatalysis.To realize this,a catalyst composed of Fe_(3)C nanoparticles and FeN_(4) single atoms anchored on carbon black(Fe_(3)C-FeN_(4)/CB)was synthesized via a synergistic strategy of spatial confinement and atmosphere control.This unique heterostructure creates interfaces between Fe_(3)C and FeN_(4) that modulate the electronic configuration of the FeN_(4) center,transforming its geometry from square-planar to quasi-octahedral.Spectroscopic characterizations and theoretical calculations reveal that this orbital modulation results in a downward shift of the Fe dband center,altering the reaction pathway and lowering the energy barrier for ORR.Consequently,the Fe_(3)C-FeN_(4)/CB catalyst exhibits outstanding ORR activity,four-electron selectivity,excellent methanol tolerance,and remarkable electrochemical stability.When applied in a zinc-air battery,it achieves a peak power density of 178.4 mW cm^(-2)and superior cycling stability compared to commercial Pt/C catalysts.This work provides valuable insights into heterointerface-induced orbital modulation as a promising design principle for high-performance ORR electrocatalysts.展开更多
The transition metal chalcogenides represented by MoS_(2)are the ideal choice for non-precious metal-based hydrogen evolution catalysts.However,whether in acidic or alkaline environments,the catalytic activity of pure...The transition metal chalcogenides represented by MoS_(2)are the ideal choice for non-precious metal-based hydrogen evolution catalysts.However,whether in acidic or alkaline environments,the catalytic activity of pure MoS_(2)is still difficult to compete with Pt.Recent studies have shown that the electronic structure of materials can be adjusted by constructing lattice-matched heterojunctions,thus optimizing the adsorption free energy of intermediates in the catalytic hydrogen production process of materials,so as to effectively improve the electrocatalytic hydrogen production activity of catalysts.However,it is still a great challenge to prepare heterojunctions with lattice-matched structures as efficient electrocatalytic hydrogen production catalysts.Herein,we developed a one-step hydrothermal method to construct Ni-MoS_(2)@NiS_(2)@Ni_(3)S_(2)(Ni-MoS_(2)on behalf of Ni doping MoS_(2))electrocatalyst with multiple heterogeneous interfaces which possesses rich catalytic reaction sites.The Ni-MoS_(2)@NiS_(2)@Ni_(3)S_(2)electrocatalyst produced an extremely low overpotential of 69.4 mV with 10 mA·cm^(−2)current density for hydrogen evolution reaction(HER)in 1.0 M KOH.This work provides valuable enlightenment for exploring the mechanism of HER enhancement to optimize the surface electronic structure of MoS_(2),and provides an effective idea for constructing rare metal catalysts in HER and other fields.展开更多
Metallic iron particles are of great potential for microwave absorption materials due to their strong magnetic loss ability.However,the oxidation susceptibility of metallic iron particles in the atmospheric environmen...Metallic iron particles are of great potential for microwave absorption materials due to their strong magnetic loss ability.However,the oxidation susceptibility of metallic iron particles in the atmospheric environment is regarded as a major factor causing performance degradation.Although many efforts have been developed to avoid their oxidation,whether partial surface oxidized iron particles can improve the microwave absorbing performance is rarely concerned.In order to explore the effect of partial surface oxidation of iron on its properties,the designed yolk–shelled(Fe/FeO_(x))@C composites with multiple heterointerfaces were synthesized via an in-situ polymerization and a finite reduction–oxidation process of Fe_(2)O_(3)ellipsoids.The performance enhancement mechanisms of Fe/FeO_(x)heterointerfaces were also elaborated.It is demonstrated that the introduction of Fe-based heterogeneous interfaces can not only enhance the dielectric loss,but also increase the imaginary part of the permeability in the higher frequency range to strengthen the magnetic loss ability.Meanwhile,the yolk–shell structure can effectively improve impedance matching and enhance microwave absorption performances via increasing multiple reflection and scattering behaviors of incident microwaves.Compared to Fe@C composite,the effective absorption(reflection loss(RL)<−10 dB)bandwidth of the optimized(Fe/FeO_(x))@C-2 increases from 5.7 to 7.3 GHz(10.7–18.0 GHz)at a same matching thickness of 2 mm,which can completely cover Ku-band.This work offers a good perspective for the enhancement of magnetic loss ability and microwave absorption performance of Fe-based microwave absorption materials with promising practical applications.展开更多
Electrochemical nitrogen reduction reaction(NRR)is a sustainable alterna-tive to the Haber-Bosch process for ammonia(NH3)production.However,the significant uphill energy in the multistep NRR pathway is a bottleneck fo...Electrochemical nitrogen reduction reaction(NRR)is a sustainable alterna-tive to the Haber-Bosch process for ammonia(NH3)production.However,the significant uphill energy in the multistep NRR pathway is a bottleneck for favorable serial reactions.To overcome this challenge,we designed a vanadium oxide/nitride(V_(2)O_(3)/VN)hybrid electrocatalyst in which V_(2)O_(3)and VN coex-ist coherently at the heterogeneous interface.Since single-phase V_(2)O_(3)and VN exhibit different surface catalytic kinetics for NRR,the V_(2)O_(3)/VN hybrid elec-trocatalyst can provide alternating reaction pathways,selecting a lower energy pathway for each material in the serial NRR pathway.As a result,the ammo-nia yield of the V_(2)O_(3)/VN hybrid electrocatalyst was 219.6µg h^(-1)cm^(-2),and the Faradaic efficiency was 18.9%,which is much higher than that of single-phase VN,V_(2)O_(3),and VNxOy solid solution catalysts without heterointerfaces.Density functional theory calculations confirmed that the composition of these hybrid electrocatalysts allows NRR to proceed from a multistep reduction reaction to a low-energy reaction pathway through the migration and adsorption of interme-diate species.Therefore,the design of metal oxide/nitride hybrids with coherent heterointerfaces provides a novel strategy for synthesizing highly efficient elec-trochemical catalysts that induce steps favorable for the efficient low-energy progression of NRR.展开更多
The heterogeneous multilayer interface of VN/Ag coatings and transition multilayer interface of VN/Ag coatings were prepared on Inconel 781 and Si(100),and the microstructures,mechanical and tribological properties we...The heterogeneous multilayer interface of VN/Ag coatings and transition multilayer interface of VN/Ag coatings were prepared on Inconel 781 and Si(100),and the microstructures,mechanical and tribological properties were investigated from 25 to 700℃.The results showed that the surface roughness and average grain size of VN/Ag coatings with transition multilayer interface are obviously larger than those of VN/Ag coatings with heterogeneous multilayer interface.The coatings with transition multilayer interface have higher adhesion force and hardness than the coatings with heterogeneous multilayer interface,and both coatings can effectively restrict the initiation and propagation of microcracks.Both coatings have excellent self-adaptive lubricating properties with a decrease of friction coefficient as the temperature increases,but their wear rates reveal a drastic increase.The phase composition of the worn area of both coatings was investigated,which indicates that a smooth Ag,Magnéli phase(V2O5)and bimetallic oxides(Ag3VO4 and AgVO3)can be responsible to the excellent lubricity of both coatings.To sum up,the coatings with transition multilayer interface have excellent adaptive lubricating properties and can properly control the diffusion rate and release rate of the lubricating phase,indicating that they have great potential in solving the problem of friction and wear of mechanical parts.展开更多
The formation of interphase layers,including the cathode-electrolyte interphase(CEI)and solidelectrolyte interphase(SEI),exhibits significant chemical complexity and plays a pivotal role in determining the performance...The formation of interphase layers,including the cathode-electrolyte interphase(CEI)and solidelectrolyte interphase(SEI),exhibits significant chemical complexity and plays a pivotal role in determining the performance of lithium batteries.Despite considerable advances in simulating the bulk phase properties of battery materials,the understanding of interfaces,including crystalline interfaces that represent the simplest case,remains limited.This is primarily due to challenges in performing ground-state searches for interface microstructures and the high computational costs associated with first-principles methods.Herein,we introduce InterOptimus,an automated workflow designed to efficiently search for ground-state heterogeneous interfaces.InterOptimus incorporates a rigorous,symmetry-aware equivalence analysis for lattice matching and termination scanning.Additionally,it introduces stereographic projection as an intuitive and comprehensive framework for visualizing and classifying interface structures.By integrating universal machine learning interatomic potentials(MLIPs),InterOptimus enables rapid predictions of interface energy and stability,significantly reducing the necessary computational cost in density functional theory(DFT)by over 90%.We benchmarked several MLIPs at three critical lithium battery interfaces,Li_(2)S|Ni_(3)S_(2),LiF|NCM,and Li_(3)PS_(4)|Li,and demonstrated that the MLIPs achieve accuracy comparable to DFT in modeling potential energy surfaces and ranking interface stabilities.Thus,InterOptimus facilitates the efficient determination of ground-state heterogeneous interface structures and subsequent studies of structure-property relationships,accelerating the interface engineering of novel battery materials.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
The design of efficient and cost‐effective bifunctional catalysts, which are capable of driving both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), is of paramount importance for advancing...The design of efficient and cost‐effective bifunctional catalysts, which are capable of driving both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), is of paramount importance for advancing overall water splitting. Here, we developed an innovative heterogeneous interface engineering strategy to boost the electrocatalytic performance of overall water splitting. This approach involves the synergistic integration of ultra‐fine CoMoP nanocrystals coupled with three‐ dimensional (3D) porous C3N4/N‐doped carbon (NC) architectures, constructing a distinctive CoMoP/C3N4/NC heterogeneous interface. The CoMoP/C3N4/NC exhibits distinguished overall water splitting performance. To drive the overall water splitting current of 10 mA cm−2, the CoMoP/C3N4/NC||CoMoP/C3N4/NC electrolysis cell only needs an ultralow cell voltage of 1.496 V. The electronic properties and localized coordination environments characterizations, and density functional theory (DFT) calculations elucidate that the improved catalytic activities of CoMoP/C3N4/NC are primarily attributed to the synergistic interfacial coupling between CoMoP/C3N4/NC heterogeneous interface. A novel multi‐site synergistic catalytic mechanism was revealed by the DFT calculations, in which the optimum H* adsorption site on CoMoP/C3N4/NC for HER is on the cobalt atoms in CoMoP with the ultralow Gibbs free energy of hydrogen bonding (ΔGH*) of 0.018 eV, while for the OER, the optimum intermediates adsorption site of the CoMoP/C3N4/NC is on the carbon atoms in C3N4/NC. Besides, the intricately engineered 3D hierarchical porous framework of the CoMoP/C3N4/NC can facilitate the ion and electron transport and improve mass transfer, which gives rise to enhanced water splitting performance.展开更多
Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion...Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion at low potentials remains challenging due to complex multi-electron transfer processes and competing reactions.Herein,we tackle this challenge by developing a cascade catalysis approach using synergistic active sites at Cu-Fe_(2)O_(3)interfaces,significantly reducing the NO_(3)^(-)to NH_(3)at a low onset potential to about+0.4 V_(RHE).Specifically,Cu optimizes^(*)NO_(3)adsorption,facilitating NO_(3)^(-)to nitrite(NO_(2)-)conversion,while adjacent Fe species in Fe_(2)O_(3)promote the subsequent NO_(2)-reduction to NH_(3)with favorable^(*)NO_(2)adsorption.Electrochemical operating experiments,in situ Raman spectroscopy,and in situ infrared spectroscopy consolidate this improved onset potential and reduction kinetics via cascade catalysis.An NH_(3)partial current density of~423 mA cm^(-2)and an NH_(3)Faradaic efficiency(FENH_(3))of 99.4%were achieved at-0.6 V_(RHE),with a maximum NH_(3)production rate of 2.71 mmol h^(-1)cm^(-2)at-0.8 V_(RHE).Remarkably,the half-cell energy efficiency exceeded 35%at-0.27 V_(RHE)(80%iR corrected),maintaining an FENH_(3)above 90%across a wide range of NO_(3)^(-)concentrations(0.05^(-1)mol L^(-1)).Using 15N isotopic tracing,we confirmed NO_(3)^(-)as the sole nitrogen source and attained a 98%NO_(3)^(-)removal efficiency.The catalyst exhibit stability over 106-h of continuous operation without noticeable degradation.This work highlights distinctive active sites in Cu-Fe_(2)O_(3)for promoting the cascade NO_(3)^(-)to NO_(2)^(-)and NO_(2)^(-)to NH_(3)electrolysis at industrial relevant current densities.展开更多
Designing cost-effective and high-efficiency electrocatalysts is critical to the water splitting performance during hydrogen generation.Herein,we have developed Fe_(2)P-Co_(2)P heterostructure nanowire arrays with exc...Designing cost-effective and high-efficiency electrocatalysts is critical to the water splitting performance during hydrogen generation.Herein,we have developed Fe_(2)P-Co_(2)P heterostructure nanowire arrays with excellent lattice torsions and grain boundaries for highly efficient water splitting.According to the microstructural investigations and theoretical calculations,the lattice torsion interface not only contributes to the exposure of more active sites but also effectively tunes the adsorption energy of hydrogen/oxygen intermediates via the accumulation of charge redistribution.As a result,the Fe_(2)P-Co_(2)P heterostructure nanowire array exhibits exceptional bifunctional catalytic activity with overpotentials of 65 and 198 mV at 10 mA cm^(-2) for hydrogen and oxygen evolution reactions,respectively.Moreover,the Fe_(2)P-Co_(2)P/NF-assembled electrolyzer can deliver 10 mA cm^(-2) at an ultralow voltage of1.51 V while resulting in a high solar-to-hydrogen conversion efficiency of 19.8%in the solar-driven water electrolysis cell.展开更多
Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT...Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.展开更多
The total internal reflection(TIR)behavior of interface shear waves is crucial for ensuring the reliability of dielectric elastomer(DE)devices.However,due to the complex force-electric coupling and large deformation o...The total internal reflection(TIR)behavior of interface shear waves is crucial for ensuring the reliability of dielectric elastomer(DE)devices.However,due to the complex force-electric coupling and large deformation of DEs,the TIR behavior of shear waves in heterogeneous force-electric interface models is still unclear.This study modeled an elastic/DE bi-material interface to analyze the trajectory of out-of-plane shear waves.Employing Dorfmann and Ogden’s nonlinear electroelastic framework and the related linear small incremental motion theory,a method has been developed to control the TIR behavior of interface shear waves.It has been found that the TIR behavior is significantly influenced by the strain-stiffening effect induced by biasing fields.Consequently,a biasing field principle involving preset electric displacement and pre-stretch has been proposed for TIR occurrence.By controlling the pre-stretch and preset electric displacement,active regulation of TIR behavior can be achieved.These results suggest a potential method for achieving autonomous energy shielding to improve the reliability of DE devices.展开更多
There is limited research reported on the multiple loss mechanism of electromagnetic waves(EMW)and the development of interface models.Dielectric loss and magnetic loss,as the two primary attenuation mechanisms in EMW...There is limited research reported on the multiple loss mechanism of electromagnetic waves(EMW)and the development of interface models.Dielectric loss and magnetic loss,as the two primary attenuation mechanisms in EMW absorbers,still pose challenges,especially in elucidating the correlation between composition,morphology,interface,and performance.Here,we construct 3D hierarchical porous conducting network structures and Schottky heterojunctions(MoNi_(4)@NC-NiFe_(2)O_(4)@NC)with a high density of defects,using trimetallic NiMoFe-MOFs.Synergistic enhancement of the dielectric and magnetic losses is realized through manipulation of the defects,interfaces,phase engineering,and magnetic resonance.In particular,the even dispersion of magnetic MoNi_(4) and NiFe_(2)O_(4)nanoparticles(NPs)within the carbon matrix triggers the creation of multiple heterogeneous interfaces.These inseparable interfaces,along with oxygen vacancies,play a role in enhancing dielectric polarization,while the closely spaced interactions among magnetic units contribute to magnetic loss.After optimizing the interfacial structure,NiFe_(2)O_(4)/MoNi_(4)-NC exhibits remarkable EMW absorption properties.A reflection loss(RL)value of-67.91 dB can be achieved at an ultra-thin thickness of 1.95 mm,and the effective absorption bandwidth(EAB,RL≤-10 dB)is as high as 5.76 GHz.Furthermore,we conducted radar scattering cross-section(RCS)simulations using computer simulation technology(CST)software,which revealed that NiFe_(2)O_(4)/MoNi_(4)-NC exhibits an RCS reduction value of 39.1 dB m^(2).Hence,this work provides comprehensive guidance for the construction of Schottky heterojunctions for lightweight EMW absorbers from a mechanistic point of view.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 National Natural Science Foundation of China(Nos.52103334,52071053,U1704253,52272288,52401035)the Fundamental Research Funds for the Central Universities(No.DUT24GF102).
文摘The rational construction of lightweight composites with multiple heterogeneous interfaces represents an effective strategy for achieving efficient electromagnetic wave(EMW)absorption.However,the impact of multiple heterogeneous interfaces on electromagnetic performance still needs further exploration.Herein,reduced graphene oxide(rGO)@Ni-FeCo layered hydroxide(LDH)derivatives with multiple heterostructures were synthesized by a series of processes including electrostatic self-assembly,freeze-drying and thermal annealing.The conductive network in rGO and the cavities inside LDH facilitate electron migration and effectively prolong the propagation path of EMW,thereby enhancing conductivity loss.The abundant heterogeneous interfaces between carbon components and metal nanoparticles induce interfacial polarization.In addition,the catalytic activity differences of different metal particles generate different dielectric electromagnetic interfaces,which further promote interfacial polarization.The natural and exchange resonance formed by magnetic particles under a magnetic field provides magnetic losses.Therefore,the successful construction of multiple heterogeneous interfaces effectively enhances the conductivity loss and polarization loss.With a thickness of only 1.4 mm,the composite achieves a minimum reflection loss of-51.8 dB and an effective absorption bandwidth of 4.5 GHz.This work provides an effective strategy for achieving thin thickness and efficient EMW absorption through precise structural design and multi-component construction of absorbers.
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financially supported by the National Natural Science Foundation of China(No.22265031)the Yunnan Univer-sity Scientific Research and Innovation Program(Nos.KC-23236054 and KC-24249310)the Program for Innovative Research Team(in Science and Technology)at the University of Yunnan Province.
文摘One-dimensional(1D)carbon nanofibers with unique three-dimensional(3D)network structure and high electrical conductivity are an important microwave absorbing material.However,due to poor impedance matching and single loss mechanism,its effective absorption bandwidth(EAB)is limited.Therefore,in this work,a porous hollow carbon fiber is designed using coaxial electrostatic spinning,and the magnetic component CoFe alloy is introduced during high temperature sintering to prepare porous CoFe hollow carbon fiber composite(CF@HCF).Its unique 1D nanostructure and 3D interconnected structure facili-tates multiple reflection losses of electromagnetic waves within the material.In addition,the presence of porous and hollow structures increases heterogeneous interfaces and surface area.The introduction of magnetic components on carbon fibers not only increases the magnetic loss,but also forms a variety of heterogeneous interfaces.In addition,the porous hollow structure improves the spatial efficiency and porosity of the composites,thus optimizing impedance matching.The results indicate that,at a filler ra-tio of 25 wt%,the EAB reaches 7.04 GHz,with a minimum reflection loss(RL_(min))of−50.04 dB under a matching thickness of 2.4 mm.In addition,to extend practical applications,CF@HCF composite membrane with excellent flexibility was prepared using PDMS encapsulation technology,and the sample also shows an average electromagnetic shielding performance of>30 dB.Besides,the radar cross section(RCS)val-ues are below−10 dB m²,demonstrating the material’s significant radar wave attenuation capability and practical application potential.This work provides some perspectives on the preparation of hollow carbon fiber magnetic powder composites,and lays the foundation for the application of magnetic carbon-based composites.
基金supported by the National Key Re-search and Development Program of China(No.2021YFB3702603)the Innovation Foundation for Doctor Dissertation of Northwest-ern Polytechnical University(No.CX2023045)+2 种基金the National Nat-ural Science Foundation of China(No.52174377)Chongqing Technology Innovation and Application Development Project(No.CSTB2022TIAD-KPX0032)the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(No.2022-TS-06).
文摘TiAl/Ti_(2)AlNb intermetallic-intermetallic laminated(IIL)composites featuring brittle/ductile heterogeneous interfaces were fabricated through vacuum hot-pack rolling.The microstructures and the phase transfor-mation behaviors of the interfaces of the IIL composites before and after annealing at 900°C/6 h were in-vestigated.The heterogeneous interfaces are composed of four distinct regions,individually I(β_(o)+γ+α_(2)),II(β_(o)/B_(2)+ω)(brittle part),III(O lath),and IV(equiaxed O)(ductile part)regions from TiAl to Ti_(2)AlNb side.Notably,after annealing,an equiaxed O band approximately 50μm wide was observed in region IV of the interface.In addition,a significant microhardness variation was observed between regions II and IV of the interface,where region II exhibited higher hardness compared to the TiAl alloy,and region IV displayed lower hardness than the Ti_(2)AlNb alloy.The enhanced fracture toughness of the IIL composites,three times that of the TiAl base alloy,is attributed to the formation of the brittle/ductile heterogeneous interfaces and the layered design incorporating the Ti_(2)AlNb alloy.The corresponding toughening mech-anism was further discussed.The brittle II region plays a role in increasing crack branching,while the ductile IV region inhibits the propagation of microcracks and prevents the formation of main cracks.This work highlights the crucial role of the brittle/ductile heterogeneous interface in the toughening of lam-inated composites.Furthermore,the discovery of the O band provides novel insights into the design of TiAl/Ti_(2)AlNb heterostructures.
基金financially supported by the National Nature Science Foundation of Jiangsu Province(BK20221259)。
文摘Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion batteries.However,due to low inherent conductivity and significant volume expansion,the electrochemical performance is greatly limited.In this study,a nickel/manganese sulfide material(Ni_(0.96)S_(x)/MnS_(y)-NC)with adjustable sulfur vacancies and heterogeneous hollow spheres was prepared using a simple method.The introduction of a concentration-adjustable sulfur vacancy enables the generation of a heterogeneous interface between bimetallic sulfide and sulfur vacancies.This interface collectively creates an internal electric field,improving the mobility of electrons and ions,increasing the number of electrochemically active sites,and further optimizing the performance of Na~+storage.The direction of electron flow is confirmed by Density functional theory(DFT)calculations.The hollow nano-spherical material provides a buffer for expansion,facilitating rapid transfer kinetics.Our innovative discovery involves the interaction between the ether-based electrolyte and copper foil,leading to the formation of Cu_9S_5,which grafts the active material and copper current collector,reinforcing mechanical supporting.This results in a new heterostructure of Cu_9S_5 with Ni_(0.96)S_(x)/MnS_(y),contributing to the stabilization of structural integrity for long-cycle performance.Therefore,Ni_(0.96)S_(x)/MnS_(y)-NC exhibits excellent electrochemical properties following our modification route.Regarding stability performance,Ni0_(.96)S_(x)/MnS_(y)-NC demonstrates an average decay rate of 0.00944%after 10,000 cycles at an extremely high current density of 10000 mA g^(-1),A full cell with a high capacity of 304.2 mA h g^(-1)was also successfully assembled by using Na_(3)V_(2)(PO_(4))_(3)/C as the cathode.This study explores a novel strategy for interface/vacancy co-modification in the fabrication of high-performance sodium-ion batteries electrode.
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)+1 种基金Natural Science Foundation of Shandong Province(Nos.ZR2024ME046 and ZR2024QE313)Postdoctoral Science Foundation of China(No.2024M761554).
文摘In view of the current serious electromagnetic pollution problem,it is urgent to study efficient electromagnetic wave absorbing materials.The construction of multiphase inhomogeneous interfaces is an effective means,especially for the fine design of multicomponent materials.In this study,multiphase composites with tunable heterogeneous interfaces were prepared by hydrothermal synthesis,carbon coating and high-temperature annealing processes.Multiple component composites constructed rich heterogeneous interfaces,which exhibited strong interfacial polarization effects and effectively improved the absorption efficiency of electromagnetic wave(EMW).The fine tuning of the heterogeneous interfaces is achieved through component adjustment,which enhances the charge carrier transport efficiency and the polarization loss capability.Ultimately,the multiphase VS_(2)@C@WS_(2)composites obtained excellent EMW absorption performance,with the minimum reflection loss and the maximum effective absorption bandwidth of-66.35 dB and 5.12 GHz,respectively.In this work,the controllable construction of heterogeneous interfaces is achieved through the tuning of components,which provides a valuable method for optimizing the polarization loss.
基金supported by the National Natural Science Foundation of China(Grant Nos.22272105 and 22572118)Natural Science Foundation of Shanghai(Grant No.23ZR1423900)。
文摘Optimizing the oxygen reduction reaction(ORR)kinetics requires precise control of intermediate adsorption at active sites,which can be achieved through orbital engineering by regulating the electronic structure.This study addresses the challenge by exploring how modulation of the 3d-orbital electronic structure of FeN_(4) active sites influences ORR electrocatalysis.To realize this,a catalyst composed of Fe_(3)C nanoparticles and FeN_(4) single atoms anchored on carbon black(Fe_(3)C-FeN_(4)/CB)was synthesized via a synergistic strategy of spatial confinement and atmosphere control.This unique heterostructure creates interfaces between Fe_(3)C and FeN_(4) that modulate the electronic configuration of the FeN_(4) center,transforming its geometry from square-planar to quasi-octahedral.Spectroscopic characterizations and theoretical calculations reveal that this orbital modulation results in a downward shift of the Fe dband center,altering the reaction pathway and lowering the energy barrier for ORR.Consequently,the Fe_(3)C-FeN_(4)/CB catalyst exhibits outstanding ORR activity,four-electron selectivity,excellent methanol tolerance,and remarkable electrochemical stability.When applied in a zinc-air battery,it achieves a peak power density of 178.4 mW cm^(-2)and superior cycling stability compared to commercial Pt/C catalysts.This work provides valuable insights into heterointerface-induced orbital modulation as a promising design principle for high-performance ORR electrocatalysts.
基金the National Natural Science Foundation of China(No.51902101)Natural Science Foundation of Jiangsu Province(No.BK20201381)+1 种基金Science Foundation of Nanjing University of Posts and Telecommunications(Nos.NY219144 and NY221046)the National College Student Innovation and Entrepreneurship Training Program(No.202210293171K).
文摘The transition metal chalcogenides represented by MoS_(2)are the ideal choice for non-precious metal-based hydrogen evolution catalysts.However,whether in acidic or alkaline environments,the catalytic activity of pure MoS_(2)is still difficult to compete with Pt.Recent studies have shown that the electronic structure of materials can be adjusted by constructing lattice-matched heterojunctions,thus optimizing the adsorption free energy of intermediates in the catalytic hydrogen production process of materials,so as to effectively improve the electrocatalytic hydrogen production activity of catalysts.However,it is still a great challenge to prepare heterojunctions with lattice-matched structures as efficient electrocatalytic hydrogen production catalysts.Herein,we developed a one-step hydrothermal method to construct Ni-MoS_(2)@NiS_(2)@Ni_(3)S_(2)(Ni-MoS_(2)on behalf of Ni doping MoS_(2))electrocatalyst with multiple heterogeneous interfaces which possesses rich catalytic reaction sites.The Ni-MoS_(2)@NiS_(2)@Ni_(3)S_(2)electrocatalyst produced an extremely low overpotential of 69.4 mV with 10 mA·cm^(−2)current density for hydrogen evolution reaction(HER)in 1.0 M KOH.This work provides valuable enlightenment for exploring the mechanism of HER enhancement to optimize the surface electronic structure of MoS_(2),and provides an effective idea for constructing rare metal catalysts in HER and other fields.
基金supported by the National Natural Science Foundation of China(Nos.21771151 and 21931009)the Natural Science Foundation of Fujian Province of China(No.2022J01042).
文摘Metallic iron particles are of great potential for microwave absorption materials due to their strong magnetic loss ability.However,the oxidation susceptibility of metallic iron particles in the atmospheric environment is regarded as a major factor causing performance degradation.Although many efforts have been developed to avoid their oxidation,whether partial surface oxidized iron particles can improve the microwave absorbing performance is rarely concerned.In order to explore the effect of partial surface oxidation of iron on its properties,the designed yolk–shelled(Fe/FeO_(x))@C composites with multiple heterointerfaces were synthesized via an in-situ polymerization and a finite reduction–oxidation process of Fe_(2)O_(3)ellipsoids.The performance enhancement mechanisms of Fe/FeO_(x)heterointerfaces were also elaborated.It is demonstrated that the introduction of Fe-based heterogeneous interfaces can not only enhance the dielectric loss,but also increase the imaginary part of the permeability in the higher frequency range to strengthen the magnetic loss ability.Meanwhile,the yolk–shell structure can effectively improve impedance matching and enhance microwave absorption performances via increasing multiple reflection and scattering behaviors of incident microwaves.Compared to Fe@C composite,the effective absorption(reflection loss(RL)<−10 dB)bandwidth of the optimized(Fe/FeO_(x))@C-2 increases from 5.7 to 7.3 GHz(10.7–18.0 GHz)at a same matching thickness of 2 mm,which can completely cover Ku-band.This work offers a good perspective for the enhancement of magnetic loss ability and microwave absorption performance of Fe-based microwave absorption materials with promising practical applications.
基金National Research Foundation of Korea,Grant/Award Numbers:2022R1A2C1012419,2022R1A2C1011559,2022R1C1C1007004。
文摘Electrochemical nitrogen reduction reaction(NRR)is a sustainable alterna-tive to the Haber-Bosch process for ammonia(NH3)production.However,the significant uphill energy in the multistep NRR pathway is a bottleneck for favorable serial reactions.To overcome this challenge,we designed a vanadium oxide/nitride(V_(2)O_(3)/VN)hybrid electrocatalyst in which V_(2)O_(3)and VN coex-ist coherently at the heterogeneous interface.Since single-phase V_(2)O_(3)and VN exhibit different surface catalytic kinetics for NRR,the V_(2)O_(3)/VN hybrid elec-trocatalyst can provide alternating reaction pathways,selecting a lower energy pathway for each material in the serial NRR pathway.As a result,the ammo-nia yield of the V_(2)O_(3)/VN hybrid electrocatalyst was 219.6µg h^(-1)cm^(-2),and the Faradaic efficiency was 18.9%,which is much higher than that of single-phase VN,V_(2)O_(3),and VNxOy solid solution catalysts without heterointerfaces.Density functional theory calculations confirmed that the composition of these hybrid electrocatalysts allows NRR to proceed from a multistep reduction reaction to a low-energy reaction pathway through the migration and adsorption of interme-diate species.Therefore,the design of metal oxide/nitride hybrids with coherent heterointerfaces provides a novel strategy for synthesizing highly efficient elec-trochemical catalysts that induce steps favorable for the efficient low-energy progression of NRR.
基金Project(51505100)supported by the National Natural Science Foundation of China
文摘The heterogeneous multilayer interface of VN/Ag coatings and transition multilayer interface of VN/Ag coatings were prepared on Inconel 781 and Si(100),and the microstructures,mechanical and tribological properties were investigated from 25 to 700℃.The results showed that the surface roughness and average grain size of VN/Ag coatings with transition multilayer interface are obviously larger than those of VN/Ag coatings with heterogeneous multilayer interface.The coatings with transition multilayer interface have higher adhesion force and hardness than the coatings with heterogeneous multilayer interface,and both coatings can effectively restrict the initiation and propagation of microcracks.Both coatings have excellent self-adaptive lubricating properties with a decrease of friction coefficient as the temperature increases,but their wear rates reveal a drastic increase.The phase composition of the worn area of both coatings was investigated,which indicates that a smooth Ag,Magnéli phase(V2O5)and bimetallic oxides(Ag3VO4 and AgVO3)can be responsible to the excellent lubricity of both coatings.To sum up,the coatings with transition multilayer interface have excellent adaptive lubricating properties and can properly control the diffusion rate and release rate of the lubricating phase,indicating that they have great potential in solving the problem of friction and wear of mechanical parts.
基金supported by the National Natural Science Foundation of China(92470110)the Special Funds for the Development of Strategic Emerging Industries in Shenzhen(XMHT20240108008)the Shenzhen Stable Support Program for Higher Education Institutions(WDZC20231126215806001)。
文摘The formation of interphase layers,including the cathode-electrolyte interphase(CEI)and solidelectrolyte interphase(SEI),exhibits significant chemical complexity and plays a pivotal role in determining the performance of lithium batteries.Despite considerable advances in simulating the bulk phase properties of battery materials,the understanding of interfaces,including crystalline interfaces that represent the simplest case,remains limited.This is primarily due to challenges in performing ground-state searches for interface microstructures and the high computational costs associated with first-principles methods.Herein,we introduce InterOptimus,an automated workflow designed to efficiently search for ground-state heterogeneous interfaces.InterOptimus incorporates a rigorous,symmetry-aware equivalence analysis for lattice matching and termination scanning.Additionally,it introduces stereographic projection as an intuitive and comprehensive framework for visualizing and classifying interface structures.By integrating universal machine learning interatomic potentials(MLIPs),InterOptimus enables rapid predictions of interface energy and stability,significantly reducing the necessary computational cost in density functional theory(DFT)by over 90%.We benchmarked several MLIPs at three critical lithium battery interfaces,Li_(2)S|Ni_(3)S_(2),LiF|NCM,and Li_(3)PS_(4)|Li,and demonstrated that the MLIPs achieve accuracy comparable to DFT in modeling potential energy surfaces and ranking interface stabilities.Thus,InterOptimus facilitates the efficient determination of ground-state heterogeneous interface structures and subsequent studies of structure-property relationships,accelerating the interface engineering of novel battery 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 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(Grant No.12375303)the Natural Science Foundation of Guangdong Province(Grants No.2024A1515030034 and 2023A1515140156).
文摘The design of efficient and cost‐effective bifunctional catalysts, which are capable of driving both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), is of paramount importance for advancing overall water splitting. Here, we developed an innovative heterogeneous interface engineering strategy to boost the electrocatalytic performance of overall water splitting. This approach involves the synergistic integration of ultra‐fine CoMoP nanocrystals coupled with three‐ dimensional (3D) porous C3N4/N‐doped carbon (NC) architectures, constructing a distinctive CoMoP/C3N4/NC heterogeneous interface. The CoMoP/C3N4/NC exhibits distinguished overall water splitting performance. To drive the overall water splitting current of 10 mA cm−2, the CoMoP/C3N4/NC||CoMoP/C3N4/NC electrolysis cell only needs an ultralow cell voltage of 1.496 V. The electronic properties and localized coordination environments characterizations, and density functional theory (DFT) calculations elucidate that the improved catalytic activities of CoMoP/C3N4/NC are primarily attributed to the synergistic interfacial coupling between CoMoP/C3N4/NC heterogeneous interface. A novel multi‐site synergistic catalytic mechanism was revealed by the DFT calculations, in which the optimum H* adsorption site on CoMoP/C3N4/NC for HER is on the cobalt atoms in CoMoP with the ultralow Gibbs free energy of hydrogen bonding (ΔGH*) of 0.018 eV, while for the OER, the optimum intermediates adsorption site of the CoMoP/C3N4/NC is on the carbon atoms in C3N4/NC. Besides, the intricately engineered 3D hierarchical porous framework of the CoMoP/C3N4/NC can facilitate the ion and electron transport and improve mass transfer, which gives rise to enhanced water splitting performance.
文摘Electrochemical nitrate(NO_(3)^(-))reduction offers a promising route for ammonia(NH_(3))synthesis from industrial wastewater using renewable energy.However,achieving selective and active NO_(3)^(-)to NH_(3)conversion at low potentials remains challenging due to complex multi-electron transfer processes and competing reactions.Herein,we tackle this challenge by developing a cascade catalysis approach using synergistic active sites at Cu-Fe_(2)O_(3)interfaces,significantly reducing the NO_(3)^(-)to NH_(3)at a low onset potential to about+0.4 V_(RHE).Specifically,Cu optimizes^(*)NO_(3)adsorption,facilitating NO_(3)^(-)to nitrite(NO_(2)-)conversion,while adjacent Fe species in Fe_(2)O_(3)promote the subsequent NO_(2)-reduction to NH_(3)with favorable^(*)NO_(2)adsorption.Electrochemical operating experiments,in situ Raman spectroscopy,and in situ infrared spectroscopy consolidate this improved onset potential and reduction kinetics via cascade catalysis.An NH_(3)partial current density of~423 mA cm^(-2)and an NH_(3)Faradaic efficiency(FENH_(3))of 99.4%were achieved at-0.6 V_(RHE),with a maximum NH_(3)production rate of 2.71 mmol h^(-1)cm^(-2)at-0.8 V_(RHE).Remarkably,the half-cell energy efficiency exceeded 35%at-0.27 V_(RHE)(80%iR corrected),maintaining an FENH_(3)above 90%across a wide range of NO_(3)^(-)concentrations(0.05^(-1)mol L^(-1)).Using 15N isotopic tracing,we confirmed NO_(3)^(-)as the sole nitrogen source and attained a 98%NO_(3)^(-)removal efficiency.The catalyst exhibit stability over 106-h of continuous operation without noticeable degradation.This work highlights distinctive active sites in Cu-Fe_(2)O_(3)for promoting the cascade NO_(3)^(-)to NO_(2)^(-)and NO_(2)^(-)to NH_(3)electrolysis at industrial relevant current densities.
基金financially supported by the National Natural Science Foundation of China(U2002213)the Creative Project of Engineering Research Center of Alternative Energy Materials&Devices,Ministry of Education,Sichuan University(AEMD202207)+7 种基金the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials of Guangxi University(2022GXYSOF10)the Guangdong Colleges&Universities Characteristic Innovation Project(2021KTSCX263)the Guangdong Education&Scientific Research Project(2021GXJK535)the Guangzhou Panyu Polytechnic Science&Technology Project(2021KJ01)the East-Land Middle-aged and Young Backbone Teacher of Yunnan University(C176220200)the Yunnan Applied Basic Research Projects(202001BB050006,202001BB050007)the Double Tops Joint Fund of the Yunnan Science and Technology Bureau and Yunnan University(2019FY003025)the Double First Class University Plan(C176220100042)。
文摘Designing cost-effective and high-efficiency electrocatalysts is critical to the water splitting performance during hydrogen generation.Herein,we have developed Fe_(2)P-Co_(2)P heterostructure nanowire arrays with excellent lattice torsions and grain boundaries for highly efficient water splitting.According to the microstructural investigations and theoretical calculations,the lattice torsion interface not only contributes to the exposure of more active sites but also effectively tunes the adsorption energy of hydrogen/oxygen intermediates via the accumulation of charge redistribution.As a result,the Fe_(2)P-Co_(2)P heterostructure nanowire array exhibits exceptional bifunctional catalytic activity with overpotentials of 65 and 198 mV at 10 mA cm^(-2) for hydrogen and oxygen evolution reactions,respectively.Moreover,the Fe_(2)P-Co_(2)P/NF-assembled electrolyzer can deliver 10 mA cm^(-2) at an ultralow voltage of1.51 V while resulting in a high solar-to-hydrogen conversion efficiency of 19.8%in the solar-driven water electrolysis cell.
基金the National Natural Science Foundation(No.52073187)NSAF Foundation(No.U2230202)for their financial support of this project+3 种基金National Natural Science Foundation(No.51721091)Programme of Introducing Talents of Discipline to Universities(No.B13040)State Key Laboratory of Polymer Materials Engineering(No.sklpme2022-2-03)support of China Scholarship Council
文摘Pre-polymerized vinyl trimethoxy silane(PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization,sol-gel transition and supercritical CO_(2)drying.The fabricated organic-inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size(30-40 nm),high specific surface area(559 m^(2)g^(−1)),high void fraction(91.7%)and enhanced mechanical property:(1)the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect(beneficial for infrared(IR)stealth);(2)the heterogeneous interface was beneficial for IR reflection(beneficial for IR stealth)and MWCNT polarization loss(beneficial for electromagnetic wave(EMW)attenuation);(3)the high void fraction was beneficial for enhancing thermal insulation(beneficial for IR stealth)and EMW impedance match(beneficial for EMW attenuation).Guided by the above theoretical design strategy,PVTMS@MWCNT nano-aerogel shows superior EMW absorption property(cover all Ku-band)and thermal IR stealth property(ΔT reached 60.7℃).Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity,an extremely high electromagnetic interference shielding material(66.5 dB,2.06 mm thickness)with superior absorption performance of an average absorption-to-reflection(A/R)coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz(A/R ratio more than 10)was experimentally obtained in this work.
基金supported by the National Natural Science Foundation of China(Grant No.12372154)National Science and Technology Major Project(Grant No.J2019-III-0010-0054).
文摘The total internal reflection(TIR)behavior of interface shear waves is crucial for ensuring the reliability of dielectric elastomer(DE)devices.However,due to the complex force-electric coupling and large deformation of DEs,the TIR behavior of shear waves in heterogeneous force-electric interface models is still unclear.This study modeled an elastic/DE bi-material interface to analyze the trajectory of out-of-plane shear waves.Employing Dorfmann and Ogden’s nonlinear electroelastic framework and the related linear small incremental motion theory,a method has been developed to control the TIR behavior of interface shear waves.It has been found that the TIR behavior is significantly influenced by the strain-stiffening effect induced by biasing fields.Consequently,a biasing field principle involving preset electric displacement and pre-stretch has been proposed for TIR occurrence.By controlling the pre-stretch and preset electric displacement,active regulation of TIR behavior can be achieved.These results suggest a potential method for achieving autonomous energy shielding to improve the reliability of DE devices.
基金supported by the National Natural Science Foundation of China(No.22269010)the Jiangxi Provincial Natural Science Foundation(No.20224BAB214021).
文摘There is limited research reported on the multiple loss mechanism of electromagnetic waves(EMW)and the development of interface models.Dielectric loss and magnetic loss,as the two primary attenuation mechanisms in EMW absorbers,still pose challenges,especially in elucidating the correlation between composition,morphology,interface,and performance.Here,we construct 3D hierarchical porous conducting network structures and Schottky heterojunctions(MoNi_(4)@NC-NiFe_(2)O_(4)@NC)with a high density of defects,using trimetallic NiMoFe-MOFs.Synergistic enhancement of the dielectric and magnetic losses is realized through manipulation of the defects,interfaces,phase engineering,and magnetic resonance.In particular,the even dispersion of magnetic MoNi_(4) and NiFe_(2)O_(4)nanoparticles(NPs)within the carbon matrix triggers the creation of multiple heterogeneous interfaces.These inseparable interfaces,along with oxygen vacancies,play a role in enhancing dielectric polarization,while the closely spaced interactions among magnetic units contribute to magnetic loss.After optimizing the interfacial structure,NiFe_(2)O_(4)/MoNi_(4)-NC exhibits remarkable EMW absorption properties.A reflection loss(RL)value of-67.91 dB can be achieved at an ultra-thin thickness of 1.95 mm,and the effective absorption bandwidth(EAB,RL≤-10 dB)is as high as 5.76 GHz.Furthermore,we conducted radar scattering cross-section(RCS)simulations using computer simulation technology(CST)software,which revealed that NiFe_(2)O_(4)/MoNi_(4)-NC exhibits an RCS reduction value of 39.1 dB m^(2).Hence,this work provides comprehensive guidance for the construction of Schottky heterojunctions for lightweight EMW absorbers from a mechanistic point of view.
