With the rapid development of modern electronic technology,the demand for high-performance microwave absorption materials has increased dramatically.In order to meet this demand,the electrospinning of FeNiCo/carbon na...With the rapid development of modern electronic technology,the demand for high-performance microwave absorption materials has increased dramatically.In order to meet this demand,the electrospinning of FeNiCo/carbon nanofiber(FeNiCo/CNF)composites with excellent microwave absorption properties was developed,and their potential as high frequency microwave absorption materials was evaluated.Experiment showed that FeNiCo/CNFs achieve a minimum reflection loss(RL_(min))of−55.5 dB with a matching thickness of only 1.6 mm.Microstructure analysis and electromagnetic parameter testing showed that the excellent microwave absorbing properties were mainly due to the combined effect of the network structure of carbon nanofibers and the FeNiCo alloy.This interaction promotes multiple reflections and the efficient absorption of microwaves.Computer simulation also showed that the FeNiCo/CNF composites produce an excellent radar cross-section reduction in typical radar operating frequency bands,which validates their potential application in stealth technology.This is a new concept in the development of high-performance microwave absorption materials.展开更多
Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_...Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_(2)(PO_(4))_(3)(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.展开更多
Advanced healthcare monitors for air pollution applications pose a significant challenge in achieving a balance between high-performance filtration and multifunctional smart integration.Electrospinning triboelectric n...Advanced healthcare monitors for air pollution applications pose a significant challenge in achieving a balance between high-performance filtration and multifunctional smart integration.Electrospinning triboelectric nanogenerators(TENG)provide a significant potential for use under such difficult circumstances.We have successfully constructed a high-performance TENG utilizing a novel multi-scale nanofiber architecture.Nylon 66(PA66)and chitosan quaternary ammonium salt(HACC)composites were prepared by electrospinning,and PA66/H multiscale nanofiber membranes composed of nanofibers(≈73 nm)and submicron-fibers(≈123 nm)were formed.PA66/H multi-scale nanofiber membrane as the positive electrode and negative electrode-spun PVDF-HFP nanofiber membrane composed of respiration-driven PVDF-HFP@PA66/H TENG.The resulting PVDF-HFP@PA66/H TENG based air filter utilizes electrostatic adsorption and physical interception mechanisms,achieving PM_(0.3)filtration efficiency over 99%with a pressure drop of only 48 Pa.Besides,PVDF-HFP@PA66/H TENG exhibits excellent stability in high-humidity environments,with filtration efficiency reduced by less than 1%.At the same time,the TENG achieves periodic contact separation through breathing drive to achieve self-power,which can ensure the long-term stability of the filtration efficiency.In addition to the air filtration function,TENG can also monitor health in real time by capturing human breathing signals without external power supply.This integrated system combines high-efficiency air filtration,self-powered operation,and health monitoring,presenting an innovative solution for air purification,smart protective equipment,and portable health monitoring.These findings highlight the potential of this technology for diverse applications,offering a promising direction for advancing multifunctional air filtration systems.展开更多
The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precis...The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.展开更多
With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivit...With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivity for radar antenna systems are urgently needed.Herein,a down-top strategy was employed to synthesize poly(p-phenylene benzobisoxazole)precursor nanofibers(prePNF).The prePNF was then uniformly mixed with fluorinated graphene(FG)to fabricate FG/PNF composite papers through consecutively suction filtration,hot-pressing,and thermal annealing.The hydroxyl and amino groups in prePNF enhanced the stability of FG/prePNF dispersion,while the increasedπ-πinteractions between PNF and FG after annealing improved their compatibility.The preparation time and cost of PNF paper was significantly reduced when applying this strategy,which enabled its large-scale production.Furthermore,the prepared FG/PNF composite papers exhibited excellent wave-transparent performance and thermal conductivity.When the mass fraction of FG was 40 wt%,the FG/PNF composite paper prepared via the down-top strategy achieved the wave-transparent coefficient(|T|2)of 96.3%under 10 GHz,in-plane thermal conductivity(λ_(∥))of 7.13 W m^(−1)K^(−1),and through-plane thermal conductivity(λ_(⊥))of 0.67 W m^(−1)K^(−1),outperforming FG/PNF composite paper prepared by the top-down strategy(|T|2=95.9%,λ_(∥)=5.52 W m^(−1)K^(−1),λ_(⊥)=0.52 W m^(−1)K^(−1))and pure PNF paper(|T|2=94.7%,λ_(∥)=3.04 W m^(−1)K^(−1),λ_(⊥)=0.24 W m^(−1)K^(−1)).Meanwhile,FG/PNF composite paper(with 40 wt%FG)through the down-top strategy also demonstrated outstanding mechanical properties with tensile strength and toughness reaching 197.4 MPa and 11.6 MJ m^(−3),respectively.展开更多
Constructing nanofibers with specific therapeutic effects against cancer is a challenge.Here,we present the synthesis approach and application prospects of supramolecular nanofibers,which are based on cucurbit[8]uril(...Constructing nanofibers with specific therapeutic effects against cancer is a challenge.Here,we present the synthesis approach and application prospects of supramolecular nanofibers,which are based on cucurbit[8]uril(CB[8])as the host and terpyridine lanthanum ions metal complex as the vip,constructed by layer-by-layer self-assembly through supramolecular interaction.Moreover,nanofibers with lanthanide luminescence properties exhibit surprising pH-responsive deformation properties and antibacterial behavior.In the tumor micro-environment,the dramatic reduction in the size of the nanofibers enables specific and hierarchical release of anticancer drugs in tumor cells to exert an advanced therapeutic effect.In addition,the synergistic therapeutic efficacy was achieved by reducing the excess of Gram-positive and Gram-negative bacteria surrounding tumor cells.The novel supramolecular nanofibers with sequential drug release and combined therapeutic mode provide new guidance for the synthesis of drug carrier materials and direction for the promotion of nanomaterial-mediated cancer therapy.展开更多
Ceramic aerogels(CAs)have emerged as a significant research frontier across various applications due to their lightweight,high porosity,and easily tunable structural characteristics.However,the intrinsic weak interact...Ceramic aerogels(CAs)have emerged as a significant research frontier across various applications due to their lightweight,high porosity,and easily tunable structural characteristics.However,the intrinsic weak interactions among the constituent nanoparticles,coupled with the limited toughness of traditional CAs,make them susceptible to structural collapse or even catastrophic failure when exposed to complex mechanical external forces.Unlike 0D building units,1D ceramic nanofibers(CNFs)possess a high aspect ratio and exceptional flexibility simultaneously,which are desirable building blocks for elastic CAs.This review presents the recent progress in electrospun ceramic nanofibrous aerogels(ECNFAs)that are constructed using ECNFs as building blocks,focusing on the various preparation methods and corresponding structural characteristics,strategies for optimizing mechanical performance,and a wide range of applications.The methods for preparing ECNFs and ECNFAs with diverse structures were initially explored,followed by the implementation of optimization strategies for enhancing ECNFAs,emphasizing the improvement of reinforcing the ECNFs,establishing the bonding effects between ECNFs,and designing the aggregate structures of the aerogels.Moreover,the applications of ECNFAs across various fields are also discussed.Finally,it highlights the existing challenges and potential opportunities for ECNFAs to achieve superior properties and realize promising prospects.展开更多
Nanofiber carbon aerogels with 3D interconnected microfibrillar networks exhibit fascinating physical properties and present great application potential.However,it is still a challenge to fabricate superelastic nanofi...Nanofiber carbon aerogels with 3D interconnected microfibrillar networks exhibit fascinating physical properties and present great application potential.However,it is still a challenge to fabricate superelastic nanofiber carbon aerogels owing to their extremely dilute brittle interconnections and poor fiber toughness after carbonization.Herein,aramid nanofibers(ANF)/nanocellulose(CNF)dual-fibrous carbon aerogels are prepared,which exhibited supercompressibility and superelasticity due to the"skeleton-binder"synergistic effect of ANF and CNF and the design of in-plane micro-wrinkle honeycomb structure.The"skeleton-binder"synergistic effect improves interfacial interactions of nanofibers and optimizes the stress distribution of carbon aerogel.The highly ordered honeycomb structure with in-plane microwrinkles,formed by the bidirectional freezing and the difference in volume shrinkage during the carbonization between CNFs and ANFs,endows the CNF/ANF carbon aerogel with negative Poisson's ratio and high energy absorption capacity.These strategies significantly improve the overall mechanical properties of ANF/CNF carbon aerogel including the elasticity and fatigue resistance.As a result,the ultralight carbon aerogel(3.46 mg/cm^(3))exhibits excellent supercompression(undergoing an extreme strain of 95%)and elasticity(a stress retention up to 81.38% at 90% strain with 500 cycles and 96.15% at 50%strain with 10,000 cycles).The nanofiber carbon aerogel shows excellent multifunctional properties in flexible piezoresistive sensor and anisotropic thermal insulation materials,including a desirable sensitivity(as high as 48.74 kPa^(-1))and an instant response time(~40 ms),an anisotropy factor of 3.69 and an ultralow radial thermal conductivity(0.012 W m^(-1) K^(-1)).These properties make dual-fibrous carbon aerogels highly attractive in pressure sensors and thermal management applications.展开更多
Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longr...Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longrange continuous structure of the nanofiber,ion-charged groups can be induced to form long-range continuous ion transfer channels in the nanofiber composite membrane,significantly increasing the ion conductivity of the membrane.This review stands apart from previous endeavors by offering a comprehensive overview of the strategies employed over the past decade in utilizing both electrospun and natural nanofibers as key components of proton exchange membranes and anion exchange membranes for fuel cells.Electrospun nanofibers are categorized based on their material properties into two primary groups:(1)ionomer nanofibers,inherently endowed with the ability to conduct H+(such as perfluorosulfonic acid or sulfonated poly(ether ether ketone))or OH-(e.g.,FAA-3),and(2)nonionic polymer nanofibers,comprising inert polymers like polyvinylidene difluoride,polytetrafluoroethylene,and polyacrylonitrile.Notably,the latter often necessitates surface modifications to impart ion transport channels,given their inherent proton inertness.Furthermore,this review delves into the recent progress made with three natural nanofibers derived from biodegradable cellulose—cellulose nanocrystals,cellulose nanofibers,and bacterial nanofibers—as crucial elements in polyelectrolyte membranes.The effect of the physical structure of such nanofibers on polyelectrolyte membrane properties is also briefly discussed.Lastly,the review emphasizes the challenges and outlines potential solutions for future research in the field of nanofiber-based polyelectrolyte membranes,aiming to propel the development of high-performance polymer electrolyte fuel cells.展开更多
Tetracycline(TC)is a broad-spectrum antibiotic,and its residues in the environment and food are harmful to human health.Therefore,it is essential to rapidly,sensitively,and conveniently detect TC.In this work,we devel...Tetracycline(TC)is a broad-spectrum antibiotic,and its residues in the environment and food are harmful to human health.Therefore,it is essential to rapidly,sensitively,and conveniently detect TC.In this work,we developed a portable silicon nanoparticles chelated Europium(Ⅲ)-based polyacrylonitrile(Eu-SiNPs/PAN)nanofiber membrane for rapid,sensitive,and convenient detection of TC.The Eu-SiNPs were synthesized with a facile one-pot method.The Eu-SiNPs/PAN nanofiber membrane was fabricated by electrospinning,combining Eu-SiNPs and PAN with three-dimensional porous membrane structures and UV resistance.Both the Eu-SiNPs and the Eu-SiNPs/PAN nanofiber membranes have good selectivity and anti-interference ability towards TC.The combined merits of rapid response,long storage life,easy portability,and naked-eye recognition of TC make the Eu-SiNPs/PAN nanofiber membrane a promising material for convenient TC detection applications.The practicability of these nanofiber membranes was further verified by detecting TC in real samples,such as lake water,drinking water and honey,and achieved quantitative detection.展开更多
Manganese-based chalcogenides have significant potential as anodes for sodium-ion batteries(SIBs) due to their high theoretical specific capacity, abundant natural reserves, and environmental friendliness. However, th...Manganese-based chalcogenides have significant potential as anodes for sodium-ion batteries(SIBs) due to their high theoretical specific capacity, abundant natural reserves, and environmental friendliness. However, their application is hindered by poor cycling stability, resulting from severe volume changes during cycling and slow reaction kinetics due to their complex crystal structure. Here, an efficient and straightforward strategy was employed to in-situ encapsulate single-phase porous nanocubic MnS_(0.5)Se_(0.5) into carbon nanofibers using electrospinning and the hard template method, thus forming a necklace-like porous MnS_(0.5)Se_(0.5)-carbon nanofiber composite(MnS_(0.5)Se_(0.5)@N-CNF). The introduction of Se significantly impacts both the composition and microstructure of MnS_(0.5)Se_(0.5), including lattice distortion that generates additional defects, optimization of chemical bonds, and a nano-spatially confined design. In situ/ex-situ characterization and density functional theory calculations verified that this MnS_(0.5)Se_(0.5)@N-CNF allevi- ates the volume expansion and facilitates the transfer of Na+/electron. As expected, MnS_(0.5)Se_(0.5)@N-CNF anode demonstrates excellent sodium storage performance, characterized by high initial Coulombic efficiency(90.8%), high-rate capability(370.5 m Ahg^(-1) at 10 Ag^(-1)) and long durability(over 5000 cycles at 5 Ag^(-1)). The MnS_(0.5)Se_(0.5)@N-CNF//NVP@C full cell, assembled with MnS_(0.5)Se_(0.5)@N-CNF as anode and Na_(3)V_(2)(PO_4)_(3)@C as cathode, exhibits a high energy density of 254 Wh kg^(-1) can be provided. This work presents a novel strategy to optimize the design of anode materials through structural engineering and Se substitution, while also elucidating the underlying reaction mechanisms.展开更多
Polymer-based aerogels are emerging as promising candidates for lightweight and high performance electromagnetic(EM)wave absorption materials.In this study,an ultralight and rigid poly(p-phenylene benzobisoxazole)nano...Polymer-based aerogels are emerging as promising candidates for lightweight and high performance electromagnetic(EM)wave absorption materials.In this study,an ultralight and rigid poly(p-phenylene benzobisoxazole)nanofiber(PNF)based composite aerogel with excellent EM wave absorption performance was fabricated with cobalt-nickel alloy(CoNi)nanoparticles and carbon nanotubes(CNTs)as magnetic and conductive fillers,respectively.A CNT/PNF composite aerogel was first prepared through a sol-gel and freeze-drying method,and then CoNi nanoparticles were introduced therein through hydrothermal reaction and thermal annealing to obtain the CoNi/CNT/PNF aerogel.CNTs and PNFs were interwoven and constructed a three-dimensional conductive/magnetic cage-like skeleton structure decorating with magnetic CoNi nanoparticles.The cage-like skeleton structure allowed the dissipation of EM waves through multiple mechanisms encompassing conduction loss,magnetic loss,multiple reflection,scattering,and absorption.When its thickness was 4 mm,the CoNi/CNT/PNF aerogel showed a minimal reflection loss of-44.7 dB(at 6.88 GHz),and its broad effective absorption bandwidth covered the entire X-band and Ku-band and most of the C-band(12.32 GHz,from 5.68 GHz to 18 GHz).In addition,the rigid aerogel exhibited an ultralow density(0.107 g/cm^(3)),excellent thermal insulation,and flame retardancy,demonstrating its potential application as a high-performance EM wave absorption material in the fields of aerospace and national defense.展开更多
The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofi...The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofibers(Fe_(4)N@CNF-NH_(3))as a highly efficient ORR catalyst.The Fe_(4)N@CNF-NH_(3)catalyst was synthesized via electrospinning,followed by high-temperature annealing in an NH_(3)atmosphere.This electrospinning technique ensured the uniform dispersion of Fe_(4)N nanoparticles within the carbon nanofibers(CNFs),preventing agglomeration and enhancing the availability of active sites.Structural and morphological analyses confirmed the formation of Fe_(4)N nanoparticles with a lattice spacing of 0.213 nm,surrounded by graphitic carbon structures that significantly improved the material’s conductivity and stability.Electrochemical tests demonstrated that Fe_(4)N@CNF-NH_(3)exhibited superior ORR activity,with a half-wave potential of 0.904 V,surpassing that of commercial Pt/C catalysts.This enhanced performance is attributed to the synergistic effects of Fe_(4)N nanoparticles and the conductive carbon framework,which facilitated efficient charge and mass transfer during the ORR process.Density functional theory calculations further revealed that the introduction of CNFs positively shifted the d-band center of Fe atoms,optimizing oxygen intermediate adsorption and lowering energy barriers for ORR.The practical applicability of Fe_(4)N@CNF-NH_(3)was validated through the assembly of both liquid-state and solid-state ZABs,which exhibited excellent cycling stability,high power density,and superior discharge voltage.This study offers a promising strategy for developing highly active,low-cost ORR catalysts and advances the potential for the commercialization of ZABs.展开更多
Aramid papers (AP), made of aramid fibers, demonstrate superiority in electrical insulation applications. Unfortunately, the strength and electrical insulating properties of AP remain suboptimal, primarily due to the ...Aramid papers (AP), made of aramid fibers, demonstrate superiority in electrical insulation applications. Unfortunately, the strength and electrical insulating properties of AP remain suboptimal, primarily due to the smooth surface and chemical inertness of aramid fibers. Herein, AP are modified via the nacre-mimetic structure composed of aramid nanofibers (ANF) and carbonylated basalt nanosheets (CBSNs). This is achieved by impregnating AP into an ANF-CBSNs (A-C) suspension containing a 3D ANF framework as the matrix and 2D CBSNs as fillers. The resultant biomimetic composite papers (AP/A-C composite papers) exhibit a layered “brick-and-mortar” structure, demonstrating superior mechanical and electrical insulating properties. Notably, the tensile strength and breakdown strength of AP/A-C5 composite papers reach 39.69 MPa and 22.04 kV mm^(−1), respectively, representing a 155 % and 85 % increase compared to those of the control AP. These impressive properties are accompanied with excellent volume resistivity, exceptional dielectric properties, impressive folding endurance, outstanding heat insulation, and remarkable flame retardance. The nacre-inspired strategy offers an effective approach for producing highly promising electrical insulating papers for advanced electrical equipment.展开更多
High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of...High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of phosphides.Herein,electrospinning and in situ phosphating were employed to prepare three-dimensional(3D)networks of self-supporting HEMP nanofibers with varying degrees of phosphate content.Comprehensive characterizations via X-ray diffraction and X-ray photoelectron spectroscopy,as well as density functional theory calculations,demonstrate that the introduction of phosphorus(P)atoms to HEMP carbon nanofibers mediates their electronic structure,leads to lattice expansion,which in turn enhances their catalytic performance in the hydrogen evolution reaction(HER).Moreover,the formation of metal-P bonds weakens metal-metal interaction and decreases the free energy of hydrogen adsorption,contributing to the exceptional activity observed in the HEMP catalyst.Electrochemical measurements demonstrate that the HEMP-0.75 catalyst with an ultralow loading of 1.22 wt%ruthenium(Ru)exhibits the highest HER catalytic activity and stability in a 1 M KOH electrolyte,achieving a minimal overpotential of 26 mV at a current density of 10 mA·cm^(-2)and Tafel slope of 50.9 mV·dec^(-1).展开更多
Blister wounds are featured with over-generated wound exudate and extensive skin peeling,call for breathable temporary skin with effective exudate management,and function as an extracellular matrix to accelerate regen...Blister wounds are featured with over-generated wound exudate and extensive skin peeling,call for breathable temporary skin with effective exudate management,and function as an extracellular matrix to accelerate regeneration of wound skin.Traditional extracellular matrix(ECM)mimicked nanofibrous 3D scaffold and corresponding hydrogel composites suffer from poor mechanical strength,and the wound exudate management behavior is seldom studied.Herein,we proposed the strategy to enhance the mechanical properties of a 3D nanofiber scaffold via constructing a long nanofiber(NF)and sodium alginate(SA)aerogel interpenetrated architecture(NF/SA).The as-prepared scaffold was then evaluated as temporary skin for a full-thickness defect wound.After absorption of blister fluid,the aerogel transferred into a hydrogel and imparted a wet wound care environment with a water-vapor transmission rate of(6001.90±522.04)g/(m^(2)·24 h),and Young s modulus of(2.97±0.38)MPa.The exudate was continuously refreshed by a directed and dynamic pump,followed by volatilization driven by Brownian motion.Meanwhile,the NF/SA scaffold exhibited decent compatibility with blister fluid.The basic fibroblast growth factor(bFGF)-loaded NF/SA improved the wound healing rate by 36.46%on Day 3 and 15.34%on Day 7 in the full-thickness defect wound model.展开更多
High-temperature piezoelectric sen-sors are very important in severe environments such as fire safety,aerospace and oil drills,however,most current sensors are not heat res-istant(<300℃)and are fragile,which limit...High-temperature piezoelectric sen-sors are very important in severe environments such as fire safety,aerospace and oil drills,however,most current sensors are not heat res-istant(<300℃)and are fragile,which limits their use,especially in high-temperature environ-ments.A high-temperature resistant flexible piezoelectric film based on graphene oxide(GO)/polyacrylonitrile(PAN)composites was prepared by electrospinning and thermal treat-ment.It was packed into a micro-device,which could work continuously at 500℃.The intro-duction of GO significantly increased the mechanical properties of the PAN nanofibers because the oxygen-containing func-tional groups(electronegative groups)on the surface of the GO initiated a nucleophilic attack on the PAN molecule during heat treatment,enabling the GO to initiate the cyclization of the PAN at lower heat-treatment temperatures.In addition,the abund-ant oxygen-containing functional groups on GO acted as pro-oxidants to hasten the oxidation of PAN during heat treatment.The effects of GO content and heat treatment temperature on the properties of the nanofiber films were investigated.A GO/PAN nanofiber piezoelectric sensor heat-treated at 300℃had a 9.10 V and 2.25μA peak output,which are respectively 101.3%and 78.6%higher than those of the untreated films.Cyclic testing over 5000 cycles at 350℃confirmed the stable out-put performance of the GO/PAN nanofiber piezoelectric sensor.Furthermore,a sensor heat-treated at 400℃had a sensitivity of 1.7 V/N,which is 83.5%higher than that of an untreated one.The results show that the prepared GO/PAN nanofiber piezo-electric sensor combines high temperature resistance,high flexibility,stability and high sensitivity,and may have broad applic-ations in high temperature environments such as the aerospace and petroleum industries.展开更多
The need for bi-functional catalysts that facilit-ate both the oxygen reduction(ORR)and carbon dioxide re-duction(CO_(2)RR)reactions arises from their potential to help solve the critical problems of carbon neutrality...The need for bi-functional catalysts that facilit-ate both the oxygen reduction(ORR)and carbon dioxide re-duction(CO_(2)RR)reactions arises from their potential to help solve the critical problems of carbon neutrality and renew-able energy conversion.However,there are few reports on the development of bi-functional catalysts for zinc-air bat-tery-driven CO_(2)RR devices.We introduce a novel approach for synthesizing Fe_(2)N/Fe_(3)C species embedded in nitrogen-doped carbon nanofibers by electrospinning a solution of Hemin and polyacrylonitrile in N,N-dimethylformamide.The material has an exceptional catalytic performance,with a half-wave potential of 0.91 V versus RHE for the ORR and values of over 90%for both the selectivity and Faradaic efficiency for the CO_(2)RR.The high catalytic performances are attrib-uted to the strong coupling between the Fe_(3)C/Fe_(2)N heterostructure and the Fe-N-C sites in the nitrogen-doped carbon nan-ofibers.Notably,both Fe_(3)C and Fe_(2)N play distinct roles in both the ORR and CO_(2)RR.This investigation indicates a way for designing advanced carbon-based bi-functional catalysts for use in this field.展开更多
Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of opera...Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of operation.However,the low adsorption capacity of the reported adsorbents is still a challenge for wastewater treatment with highefficiency.Here,we developed a super adsorbent(SUA-1),which was a kind of porous carbon nanofibers derived from a composite of PAN-based electrospinning and ZIF-8(PAN/ZIF-8)via simple heat treatment process.The asprepared SUA showed an ultra-high adsorption capacity for adsorbing methyl blue(MB)at nearly three times its own weight,as high as 2998.18 mg/g.A series tests demonstrated that the pore-making effect of ZIF-8 during heat treatment process endowed high BET surface area and generated ZnO components as chemical adsorption center.Under the synergistic effect of bonding and non-bonding forces including ionic bond,electrostatic interaction,andπ-πinteraction,the adsorption capacity has been greatly improved.In view of promising efficiency,this work provides guidance and insights for the preparation of highly efficient adsorbents based on electrospinning derived porous carbon nanofibers.展开更多
To address the dual challenges of resource utilization of mining solid waste(e.g.,coal gangue)and performance enhancement of cemented rockfill,this study systematically investigates the mechanisms of ultrasonic disper...To address the dual challenges of resource utilization of mining solid waste(e.g.,coal gangue)and performance enhancement of cemented rockfill,this study systematically investigates the mechanisms of ultrasonic dispersion time and polycarboxylate superplasti-cizer(PCE)on the properties of cellulose nanofiber(CNF)-modified cemented rockfill.A series of comparative experiments were de-signed with varying ultrasonic dispersion times(0-60 min)and PCE dosages(0.1wt%-0.4wt%).Through mechanical testing,hydration product analysis,and microstructural characterization,the study revealed the advantages of PCE in promoting CNF dispersion to enhance the engineering applicability of cemented rockfill.The results demonstrate that:(1)Ultrasonic dispersion for 30 min increases the com-pressive strength by 37.7%compared to the untreated group;however,excessive ultrasonication(60 min)induces hydrolysis of CNF,re-leasing reducing sugars that retard hydration.(2)PCE facilitates CNF dispersion,achieving a 29.1%increase in compressive strength at a dosage of 0.4wt%,while simultaneously improving hydration products and microstructural development.(3)While ultrasonic dispersion yields slightly higher strength improvements,PCE demonstrates superior cost-effectiveness and operational convenience,rendering it more viable for industrial adoption.This study provides a theoretical foundation for the nano-enhanced modification of cemented rockfill,offering new insights into the recycling of solid waste and the development of high-performance materials.展开更多
基金supported by the Natural Science Foundation of Shanxi Province(202203021212205)Shanxi Province Major Science and Technology Special Project‘Jiebang Guashuai’Project(202101120401008)+1 种基金National Natural Science Foundation of China(52371231)Key R&D Program of Shanxi Province(202302040201008).
文摘With the rapid development of modern electronic technology,the demand for high-performance microwave absorption materials has increased dramatically.In order to meet this demand,the electrospinning of FeNiCo/carbon nanofiber(FeNiCo/CNF)composites with excellent microwave absorption properties was developed,and their potential as high frequency microwave absorption materials was evaluated.Experiment showed that FeNiCo/CNFs achieve a minimum reflection loss(RL_(min))of−55.5 dB with a matching thickness of only 1.6 mm.Microstructure analysis and electromagnetic parameter testing showed that the excellent microwave absorbing properties were mainly due to the combined effect of the network structure of carbon nanofibers and the FeNiCo alloy.This interaction promotes multiple reflections and the efficient absorption of microwaves.Computer simulation also showed that the FeNiCo/CNF composites produce an excellent radar cross-section reduction in typical radar operating frequency bands,which validates their potential application in stealth technology.This is a new concept in the development of high-performance microwave absorption materials.
文摘Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_(2)(PO_(4))_(3)(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.
基金financial support from the National Key Research and Development Program of China(2022YFB3804905)National Natural Science Foundation of China(22375047,22378068,and 22378071)+1 种基金Natural Science Foundation of Fujian Province(2022J01568)111 Project(No.D17005).
文摘Advanced healthcare monitors for air pollution applications pose a significant challenge in achieving a balance between high-performance filtration and multifunctional smart integration.Electrospinning triboelectric nanogenerators(TENG)provide a significant potential for use under such difficult circumstances.We have successfully constructed a high-performance TENG utilizing a novel multi-scale nanofiber architecture.Nylon 66(PA66)and chitosan quaternary ammonium salt(HACC)composites were prepared by electrospinning,and PA66/H multiscale nanofiber membranes composed of nanofibers(≈73 nm)and submicron-fibers(≈123 nm)were formed.PA66/H multi-scale nanofiber membrane as the positive electrode and negative electrode-spun PVDF-HFP nanofiber membrane composed of respiration-driven PVDF-HFP@PA66/H TENG.The resulting PVDF-HFP@PA66/H TENG based air filter utilizes electrostatic adsorption and physical interception mechanisms,achieving PM_(0.3)filtration efficiency over 99%with a pressure drop of only 48 Pa.Besides,PVDF-HFP@PA66/H TENG exhibits excellent stability in high-humidity environments,with filtration efficiency reduced by less than 1%.At the same time,the TENG achieves periodic contact separation through breathing drive to achieve self-power,which can ensure the long-term stability of the filtration efficiency.In addition to the air filtration function,TENG can also monitor health in real time by capturing human breathing signals without external power supply.This integrated system combines high-efficiency air filtration,self-powered operation,and health monitoring,presenting an innovative solution for air purification,smart protective equipment,and portable health monitoring.These findings highlight the potential of this technology for diverse applications,offering a promising direction for advancing multifunctional air filtration systems.
基金supported by the National Natural Science Foundation of China(No.52403035)the Shanghai Sailing Program(23YF1400300)+1 种基金the Fundamental Research Funds for the Central Universities(2232023D-05)the Weiqiao Teaching and Research Innovation Program.
文摘The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.
基金the support from the National Natural Science Foundation of China(52473083,52373089,52403085)Natural Science Basic Research Program of Shaanxi(2024JC-TBZC-04)+2 种基金the Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57)Natural Science Basic Research Plan in Shaanxi Province of China(2024JC-YBMS-279)Natural Science Foundation of Chongqing,China(2023NSCQMSX2547)
文摘With the miniaturization and high-frequency evolution of antennas in 5G/6G communications,aerospace,and transportation,polymer composite papers integrating superior wave-transparent performance and thermal conductivity for radar antenna systems are urgently needed.Herein,a down-top strategy was employed to synthesize poly(p-phenylene benzobisoxazole)precursor nanofibers(prePNF).The prePNF was then uniformly mixed with fluorinated graphene(FG)to fabricate FG/PNF composite papers through consecutively suction filtration,hot-pressing,and thermal annealing.The hydroxyl and amino groups in prePNF enhanced the stability of FG/prePNF dispersion,while the increasedπ-πinteractions between PNF and FG after annealing improved their compatibility.The preparation time and cost of PNF paper was significantly reduced when applying this strategy,which enabled its large-scale production.Furthermore,the prepared FG/PNF composite papers exhibited excellent wave-transparent performance and thermal conductivity.When the mass fraction of FG was 40 wt%,the FG/PNF composite paper prepared via the down-top strategy achieved the wave-transparent coefficient(|T|2)of 96.3%under 10 GHz,in-plane thermal conductivity(λ_(∥))of 7.13 W m^(−1)K^(−1),and through-plane thermal conductivity(λ_(⊥))of 0.67 W m^(−1)K^(−1),outperforming FG/PNF composite paper prepared by the top-down strategy(|T|2=95.9%,λ_(∥)=5.52 W m^(−1)K^(−1),λ_(⊥)=0.52 W m^(−1)K^(−1))and pure PNF paper(|T|2=94.7%,λ_(∥)=3.04 W m^(−1)K^(−1),λ_(⊥)=0.24 W m^(−1)K^(−1)).Meanwhile,FG/PNF composite paper(with 40 wt%FG)through the down-top strategy also demonstrated outstanding mechanical properties with tensile strength and toughness reaching 197.4 MPa and 11.6 MJ m^(−3),respectively.
基金supported by the National Natural Science Foundation of China(No.82273919)Natural Science Foundation of Heilongjiang Province(No.LH2024H013)China Postdoctoral Science Foundation(No.2022MD723781).
文摘Constructing nanofibers with specific therapeutic effects against cancer is a challenge.Here,we present the synthesis approach and application prospects of supramolecular nanofibers,which are based on cucurbit[8]uril(CB[8])as the host and terpyridine lanthanum ions metal complex as the vip,constructed by layer-by-layer self-assembly through supramolecular interaction.Moreover,nanofibers with lanthanide luminescence properties exhibit surprising pH-responsive deformation properties and antibacterial behavior.In the tumor micro-environment,the dramatic reduction in the size of the nanofibers enables specific and hierarchical release of anticancer drugs in tumor cells to exert an advanced therapeutic effect.In addition,the synergistic therapeutic efficacy was achieved by reducing the excess of Gram-positive and Gram-negative bacteria surrounding tumor cells.The novel supramolecular nanofibers with sequential drug release and combined therapeutic mode provide new guidance for the synthesis of drug carrier materials and direction for the promotion of nanomaterial-mediated cancer therapy.
基金supported by the National Natural Science Foundation of China(Nos.92371110 and 52373281)Weiqiao Science Foundation(H2872302 and H2872303)the Scientific Research Innovation Capability Support Project for Young Faculty.
文摘Ceramic aerogels(CAs)have emerged as a significant research frontier across various applications due to their lightweight,high porosity,and easily tunable structural characteristics.However,the intrinsic weak interactions among the constituent nanoparticles,coupled with the limited toughness of traditional CAs,make them susceptible to structural collapse or even catastrophic failure when exposed to complex mechanical external forces.Unlike 0D building units,1D ceramic nanofibers(CNFs)possess a high aspect ratio and exceptional flexibility simultaneously,which are desirable building blocks for elastic CAs.This review presents the recent progress in electrospun ceramic nanofibrous aerogels(ECNFAs)that are constructed using ECNFs as building blocks,focusing on the various preparation methods and corresponding structural characteristics,strategies for optimizing mechanical performance,and a wide range of applications.The methods for preparing ECNFs and ECNFAs with diverse structures were initially explored,followed by the implementation of optimization strategies for enhancing ECNFAs,emphasizing the improvement of reinforcing the ECNFs,establishing the bonding effects between ECNFs,and designing the aggregate structures of the aerogels.Moreover,the applications of ECNFAs across various fields are also discussed.Finally,it highlights the existing challenges and potential opportunities for ECNFAs to achieve superior properties and realize promising prospects.
文摘Nanofiber carbon aerogels with 3D interconnected microfibrillar networks exhibit fascinating physical properties and present great application potential.However,it is still a challenge to fabricate superelastic nanofiber carbon aerogels owing to their extremely dilute brittle interconnections and poor fiber toughness after carbonization.Herein,aramid nanofibers(ANF)/nanocellulose(CNF)dual-fibrous carbon aerogels are prepared,which exhibited supercompressibility and superelasticity due to the"skeleton-binder"synergistic effect of ANF and CNF and the design of in-plane micro-wrinkle honeycomb structure.The"skeleton-binder"synergistic effect improves interfacial interactions of nanofibers and optimizes the stress distribution of carbon aerogel.The highly ordered honeycomb structure with in-plane microwrinkles,formed by the bidirectional freezing and the difference in volume shrinkage during the carbonization between CNFs and ANFs,endows the CNF/ANF carbon aerogel with negative Poisson's ratio and high energy absorption capacity.These strategies significantly improve the overall mechanical properties of ANF/CNF carbon aerogel including the elasticity and fatigue resistance.As a result,the ultralight carbon aerogel(3.46 mg/cm^(3))exhibits excellent supercompression(undergoing an extreme strain of 95%)and elasticity(a stress retention up to 81.38% at 90% strain with 500 cycles and 96.15% at 50%strain with 10,000 cycles).The nanofiber carbon aerogel shows excellent multifunctional properties in flexible piezoresistive sensor and anisotropic thermal insulation materials,including a desirable sensitivity(as high as 48.74 kPa^(-1))and an instant response time(~40 ms),an anisotropy factor of 3.69 and an ultralow radial thermal conductivity(0.012 W m^(-1) K^(-1)).These properties make dual-fibrous carbon aerogels highly attractive in pressure sensors and thermal management applications.
基金National Natural Science Foundation of China,Grant/Award Numbers:52173091,62101391。
文摘Developing low-cost and high-performance nanofiber-based polyelectrolyte membranes for fuel cell applications is a promising solution to energy depletion.Due to the high specific surface area and one-dimensional longrange continuous structure of the nanofiber,ion-charged groups can be induced to form long-range continuous ion transfer channels in the nanofiber composite membrane,significantly increasing the ion conductivity of the membrane.This review stands apart from previous endeavors by offering a comprehensive overview of the strategies employed over the past decade in utilizing both electrospun and natural nanofibers as key components of proton exchange membranes and anion exchange membranes for fuel cells.Electrospun nanofibers are categorized based on their material properties into two primary groups:(1)ionomer nanofibers,inherently endowed with the ability to conduct H+(such as perfluorosulfonic acid or sulfonated poly(ether ether ketone))or OH-(e.g.,FAA-3),and(2)nonionic polymer nanofibers,comprising inert polymers like polyvinylidene difluoride,polytetrafluoroethylene,and polyacrylonitrile.Notably,the latter often necessitates surface modifications to impart ion transport channels,given their inherent proton inertness.Furthermore,this review delves into the recent progress made with three natural nanofibers derived from biodegradable cellulose—cellulose nanocrystals,cellulose nanofibers,and bacterial nanofibers—as crucial elements in polyelectrolyte membranes.The effect of the physical structure of such nanofibers on polyelectrolyte membrane properties is also briefly discussed.Lastly,the review emphasizes the challenges and outlines potential solutions for future research in the field of nanofiber-based polyelectrolyte membranes,aiming to propel the development of high-performance polymer electrolyte fuel cells.
基金supported by the Natural Science Foundation of Tianjin(Nos.18JCQNJC72400 and 22JCQNJC01510).
文摘Tetracycline(TC)is a broad-spectrum antibiotic,and its residues in the environment and food are harmful to human health.Therefore,it is essential to rapidly,sensitively,and conveniently detect TC.In this work,we developed a portable silicon nanoparticles chelated Europium(Ⅲ)-based polyacrylonitrile(Eu-SiNPs/PAN)nanofiber membrane for rapid,sensitive,and convenient detection of TC.The Eu-SiNPs were synthesized with a facile one-pot method.The Eu-SiNPs/PAN nanofiber membrane was fabricated by electrospinning,combining Eu-SiNPs and PAN with three-dimensional porous membrane structures and UV resistance.Both the Eu-SiNPs and the Eu-SiNPs/PAN nanofiber membranes have good selectivity and anti-interference ability towards TC.The combined merits of rapid response,long storage life,easy portability,and naked-eye recognition of TC make the Eu-SiNPs/PAN nanofiber membrane a promising material for convenient TC detection applications.The practicability of these nanofiber membranes was further verified by detecting TC in real samples,such as lake water,drinking water and honey,and achieved quantitative detection.
基金financially supported by the National Natural Science Foundation of China (No. 22225902, U22A20436, 22209185)National Key Research&Development Program of China (2022YFE0115900, 2023YFA1507101, 2021YFA1501500)+1 种基金the Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences (No. CXZX-2022-GH04, CXZX-2023-JQ08)Science and Technology Program of Fuzhou (2023-P-009)。
文摘Manganese-based chalcogenides have significant potential as anodes for sodium-ion batteries(SIBs) due to their high theoretical specific capacity, abundant natural reserves, and environmental friendliness. However, their application is hindered by poor cycling stability, resulting from severe volume changes during cycling and slow reaction kinetics due to their complex crystal structure. Here, an efficient and straightforward strategy was employed to in-situ encapsulate single-phase porous nanocubic MnS_(0.5)Se_(0.5) into carbon nanofibers using electrospinning and the hard template method, thus forming a necklace-like porous MnS_(0.5)Se_(0.5)-carbon nanofiber composite(MnS_(0.5)Se_(0.5)@N-CNF). The introduction of Se significantly impacts both the composition and microstructure of MnS_(0.5)Se_(0.5), including lattice distortion that generates additional defects, optimization of chemical bonds, and a nano-spatially confined design. In situ/ex-situ characterization and density functional theory calculations verified that this MnS_(0.5)Se_(0.5)@N-CNF allevi- ates the volume expansion and facilitates the transfer of Na+/electron. As expected, MnS_(0.5)Se_(0.5)@N-CNF anode demonstrates excellent sodium storage performance, characterized by high initial Coulombic efficiency(90.8%), high-rate capability(370.5 m Ahg^(-1) at 10 Ag^(-1)) and long durability(over 5000 cycles at 5 Ag^(-1)). The MnS_(0.5)Se_(0.5)@N-CNF//NVP@C full cell, assembled with MnS_(0.5)Se_(0.5)@N-CNF as anode and Na_(3)V_(2)(PO_4)_(3)@C as cathode, exhibits a high energy density of 254 Wh kg^(-1) can be provided. This work presents a novel strategy to optimize the design of anode materials through structural engineering and Se substitution, while also elucidating the underlying reaction mechanisms.
基金the National Natural Science Foundation of China(52203100)Shaanxi Province Key Research and Development Plan Project(2024GX-YBXM-386)+3 种基金the Innovation Capability Support Program of Shaanxi(2024RS-CXTD-57)Natural Science Foundation of Chongqing,China(2023NSCQ-MSX2682)Undergraduate Innovation&Business Program of Northwestern Polytechnical University(S202310699322)the Analytical&Testing Center of Northwestern Polytechnical University for SEM tests performed in this work.
文摘Polymer-based aerogels are emerging as promising candidates for lightweight and high performance electromagnetic(EM)wave absorption materials.In this study,an ultralight and rigid poly(p-phenylene benzobisoxazole)nanofiber(PNF)based composite aerogel with excellent EM wave absorption performance was fabricated with cobalt-nickel alloy(CoNi)nanoparticles and carbon nanotubes(CNTs)as magnetic and conductive fillers,respectively.A CNT/PNF composite aerogel was first prepared through a sol-gel and freeze-drying method,and then CoNi nanoparticles were introduced therein through hydrothermal reaction and thermal annealing to obtain the CoNi/CNT/PNF aerogel.CNTs and PNFs were interwoven and constructed a three-dimensional conductive/magnetic cage-like skeleton structure decorating with magnetic CoNi nanoparticles.The cage-like skeleton structure allowed the dissipation of EM waves through multiple mechanisms encompassing conduction loss,magnetic loss,multiple reflection,scattering,and absorption.When its thickness was 4 mm,the CoNi/CNT/PNF aerogel showed a minimal reflection loss of-44.7 dB(at 6.88 GHz),and its broad effective absorption bandwidth covered the entire X-band and Ku-band and most of the C-band(12.32 GHz,from 5.68 GHz to 18 GHz).In addition,the rigid aerogel exhibited an ultralow density(0.107 g/cm^(3)),excellent thermal insulation,and flame retardancy,demonstrating its potential application as a high-performance EM wave absorption material in the fields of aerospace and national defense.
基金supported by the National Natural Science Foundation of China(No.11904208the Project of Shandong Province Higher Educational Science and Technology Program(No.J18KB098).
文摘The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofibers(Fe_(4)N@CNF-NH_(3))as a highly efficient ORR catalyst.The Fe_(4)N@CNF-NH_(3)catalyst was synthesized via electrospinning,followed by high-temperature annealing in an NH_(3)atmosphere.This electrospinning technique ensured the uniform dispersion of Fe_(4)N nanoparticles within the carbon nanofibers(CNFs),preventing agglomeration and enhancing the availability of active sites.Structural and morphological analyses confirmed the formation of Fe_(4)N nanoparticles with a lattice spacing of 0.213 nm,surrounded by graphitic carbon structures that significantly improved the material’s conductivity and stability.Electrochemical tests demonstrated that Fe_(4)N@CNF-NH_(3)exhibited superior ORR activity,with a half-wave potential of 0.904 V,surpassing that of commercial Pt/C catalysts.This enhanced performance is attributed to the synergistic effects of Fe_(4)N nanoparticles and the conductive carbon framework,which facilitated efficient charge and mass transfer during the ORR process.Density functional theory calculations further revealed that the introduction of CNFs positively shifted the d-band center of Fe atoms,optimizing oxygen intermediate adsorption and lowering energy barriers for ORR.The practical applicability of Fe_(4)N@CNF-NH_(3)was validated through the assembly of both liquid-state and solid-state ZABs,which exhibited excellent cycling stability,high power density,and superior discharge voltage.This study offers a promising strategy for developing highly active,low-cost ORR catalysts and advances the potential for the commercialization of ZABs.
基金supported by the National Natural Science Foundation of China(No.22278260)the Open Foundation of Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry(No.KFKT2021-14)Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology(No.KFKT2021-14).
文摘Aramid papers (AP), made of aramid fibers, demonstrate superiority in electrical insulation applications. Unfortunately, the strength and electrical insulating properties of AP remain suboptimal, primarily due to the smooth surface and chemical inertness of aramid fibers. Herein, AP are modified via the nacre-mimetic structure composed of aramid nanofibers (ANF) and carbonylated basalt nanosheets (CBSNs). This is achieved by impregnating AP into an ANF-CBSNs (A-C) suspension containing a 3D ANF framework as the matrix and 2D CBSNs as fillers. The resultant biomimetic composite papers (AP/A-C composite papers) exhibit a layered “brick-and-mortar” structure, demonstrating superior mechanical and electrical insulating properties. Notably, the tensile strength and breakdown strength of AP/A-C5 composite papers reach 39.69 MPa and 22.04 kV mm^(−1), respectively, representing a 155 % and 85 % increase compared to those of the control AP. These impressive properties are accompanied with excellent volume resistivity, exceptional dielectric properties, impressive folding endurance, outstanding heat insulation, and remarkable flame retardance. The nacre-inspired strategy offers an effective approach for producing highly promising electrical insulating papers for advanced electrical equipment.
基金supported by the National Natural Science Foundation of China(Nos.22103045 and 52273077)the State Key Laboratory of Bio-Fibers and Eco-Textiles,Qingdao University(Nos.ZDKT202108,RZ2000003334 and G2RC202022)support from the Australian National Fabrication Facility’s Queensland Node(No.ANFF-Q),the UQ-Yonsei International Research Project,and the JST-ERATO Yamauchi Materials Space-Tectonics Project(No.JPMJER2003).
文摘High-entropy metal phosphide(HEMP)has considerable potential as an electrocatalyst owing to its beneficial properties,including high-entropy alloy synergy as well as the controllable structure and high conductivity of phosphides.Herein,electrospinning and in situ phosphating were employed to prepare three-dimensional(3D)networks of self-supporting HEMP nanofibers with varying degrees of phosphate content.Comprehensive characterizations via X-ray diffraction and X-ray photoelectron spectroscopy,as well as density functional theory calculations,demonstrate that the introduction of phosphorus(P)atoms to HEMP carbon nanofibers mediates their electronic structure,leads to lattice expansion,which in turn enhances their catalytic performance in the hydrogen evolution reaction(HER).Moreover,the formation of metal-P bonds weakens metal-metal interaction and decreases the free energy of hydrogen adsorption,contributing to the exceptional activity observed in the HEMP catalyst.Electrochemical measurements demonstrate that the HEMP-0.75 catalyst with an ultralow loading of 1.22 wt%ruthenium(Ru)exhibits the highest HER catalytic activity and stability in a 1 M KOH electrolyte,achieving a minimal overpotential of 26 mV at a current density of 10 mA·cm^(-2)and Tafel slope of 50.9 mV·dec^(-1).
基金Natural Science Foundation of Shanghai(General Program,22ZR1409500)China Postdoctoral Science Foundation(23M742317,GZB240446)+3 种基金Shanghai Science and Technology Innovation Action Plan(22S31905500)Medical Engineering Fund of Fudan University(yg2021-032)Fundamental Research Project of CNTAC(J202104)Program of Introducing Talents of Discipline to Universities(BP0719035)。
文摘Blister wounds are featured with over-generated wound exudate and extensive skin peeling,call for breathable temporary skin with effective exudate management,and function as an extracellular matrix to accelerate regeneration of wound skin.Traditional extracellular matrix(ECM)mimicked nanofibrous 3D scaffold and corresponding hydrogel composites suffer from poor mechanical strength,and the wound exudate management behavior is seldom studied.Herein,we proposed the strategy to enhance the mechanical properties of a 3D nanofiber scaffold via constructing a long nanofiber(NF)and sodium alginate(SA)aerogel interpenetrated architecture(NF/SA).The as-prepared scaffold was then evaluated as temporary skin for a full-thickness defect wound.After absorption of blister fluid,the aerogel transferred into a hydrogel and imparted a wet wound care environment with a water-vapor transmission rate of(6001.90±522.04)g/(m^(2)·24 h),and Young s modulus of(2.97±0.38)MPa.The exudate was continuously refreshed by a directed and dynamic pump,followed by volatilization driven by Brownian motion.Meanwhile,the NF/SA scaffold exhibited decent compatibility with blister fluid.The basic fibroblast growth factor(bFGF)-loaded NF/SA improved the wound healing rate by 36.46%on Day 3 and 15.34%on Day 7 in the full-thickness defect wound model.
文摘High-temperature piezoelectric sen-sors are very important in severe environments such as fire safety,aerospace and oil drills,however,most current sensors are not heat res-istant(<300℃)and are fragile,which limits their use,especially in high-temperature environ-ments.A high-temperature resistant flexible piezoelectric film based on graphene oxide(GO)/polyacrylonitrile(PAN)composites was prepared by electrospinning and thermal treat-ment.It was packed into a micro-device,which could work continuously at 500℃.The intro-duction of GO significantly increased the mechanical properties of the PAN nanofibers because the oxygen-containing func-tional groups(electronegative groups)on the surface of the GO initiated a nucleophilic attack on the PAN molecule during heat treatment,enabling the GO to initiate the cyclization of the PAN at lower heat-treatment temperatures.In addition,the abund-ant oxygen-containing functional groups on GO acted as pro-oxidants to hasten the oxidation of PAN during heat treatment.The effects of GO content and heat treatment temperature on the properties of the nanofiber films were investigated.A GO/PAN nanofiber piezoelectric sensor heat-treated at 300℃had a 9.10 V and 2.25μA peak output,which are respectively 101.3%and 78.6%higher than those of the untreated films.Cyclic testing over 5000 cycles at 350℃confirmed the stable out-put performance of the GO/PAN nanofiber piezoelectric sensor.Furthermore,a sensor heat-treated at 400℃had a sensitivity of 1.7 V/N,which is 83.5%higher than that of an untreated one.The results show that the prepared GO/PAN nanofiber piezo-electric sensor combines high temperature resistance,high flexibility,stability and high sensitivity,and may have broad applic-ations in high temperature environments such as the aerospace and petroleum industries.
文摘The need for bi-functional catalysts that facilit-ate both the oxygen reduction(ORR)and carbon dioxide re-duction(CO_(2)RR)reactions arises from their potential to help solve the critical problems of carbon neutrality and renew-able energy conversion.However,there are few reports on the development of bi-functional catalysts for zinc-air bat-tery-driven CO_(2)RR devices.We introduce a novel approach for synthesizing Fe_(2)N/Fe_(3)C species embedded in nitrogen-doped carbon nanofibers by electrospinning a solution of Hemin and polyacrylonitrile in N,N-dimethylformamide.The material has an exceptional catalytic performance,with a half-wave potential of 0.91 V versus RHE for the ORR and values of over 90%for both the selectivity and Faradaic efficiency for the CO_(2)RR.The high catalytic performances are attrib-uted to the strong coupling between the Fe_(3)C/Fe_(2)N heterostructure and the Fe-N-C sites in the nitrogen-doped carbon nan-ofibers.Notably,both Fe_(3)C and Fe_(2)N play distinct roles in both the ORR and CO_(2)RR.This investigation indicates a way for designing advanced carbon-based bi-functional catalysts for use in this field.
基金Natural Science Foundation of China(22134005,22204011)Chongqing Talents Program for Outstanding Scientists(cstc2021ycjh-bgzxm0179)。
文摘Adsorption as an effective technique for the remediation of wastewater has been widely used in industrial wastewater treatment due to the advantage of cost-effectiveness,availability of the adsorbent and ease of operation.However,the low adsorption capacity of the reported adsorbents is still a challenge for wastewater treatment with highefficiency.Here,we developed a super adsorbent(SUA-1),which was a kind of porous carbon nanofibers derived from a composite of PAN-based electrospinning and ZIF-8(PAN/ZIF-8)via simple heat treatment process.The asprepared SUA showed an ultra-high adsorption capacity for adsorbing methyl blue(MB)at nearly three times its own weight,as high as 2998.18 mg/g.A series tests demonstrated that the pore-making effect of ZIF-8 during heat treatment process endowed high BET surface area and generated ZnO components as chemical adsorption center.Under the synergistic effect of bonding and non-bonding forces including ionic bond,electrostatic interaction,andπ-πinteraction,the adsorption capacity has been greatly improved.In view of promising efficiency,this work provides guidance and insights for the preparation of highly efficient adsorbents based on electrospinning derived porous carbon nanofibers.
基金support from the National Natural Science Foundation of China(Nos.42372328,U23B2091,52478253,and 52374147)Natural Science Foundation of Jiangsu Province,China(No.BK20240209).
文摘To address the dual challenges of resource utilization of mining solid waste(e.g.,coal gangue)and performance enhancement of cemented rockfill,this study systematically investigates the mechanisms of ultrasonic dispersion time and polycarboxylate superplasti-cizer(PCE)on the properties of cellulose nanofiber(CNF)-modified cemented rockfill.A series of comparative experiments were de-signed with varying ultrasonic dispersion times(0-60 min)and PCE dosages(0.1wt%-0.4wt%).Through mechanical testing,hydration product analysis,and microstructural characterization,the study revealed the advantages of PCE in promoting CNF dispersion to enhance the engineering applicability of cemented rockfill.The results demonstrate that:(1)Ultrasonic dispersion for 30 min increases the com-pressive strength by 37.7%compared to the untreated group;however,excessive ultrasonication(60 min)induces hydrolysis of CNF,re-leasing reducing sugars that retard hydration.(2)PCE facilitates CNF dispersion,achieving a 29.1%increase in compressive strength at a dosage of 0.4wt%,while simultaneously improving hydration products and microstructural development.(3)While ultrasonic dispersion yields slightly higher strength improvements,PCE demonstrates superior cost-effectiveness and operational convenience,rendering it more viable for industrial adoption.This study provides a theoretical foundation for the nano-enhanced modification of cemented rockfill,offering new insights into the recycling of solid waste and the development of high-performance materials.
