Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell...Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell proliferation and differentiation,thereby exerting neuroprotective effects.However,the beneficial effects of endogenous VEGFA/b FGF are limited as their expression is only transiently increased.In this study,we generated multilayered nanofiber membranes loaded with VEGFA/b FGF using layer-by-layer self-assembly and electrospinning techniques.We found that a membrane containing 10 layers had an ideal ultrastructure and could efficiently and stably release growth factors for more than 1 month.This 10-layered nanofiber membrane promoted brain microvascular endothelial cell tube formation and proliferation,inhibited neuronal apoptosis,upregulated the expression of tight junction proteins,and improved the viability of various cellular components of neurovascular units under conditions of oxygen/glucose deprivation.Furthermore,this nanofiber membrane decreased the expression of Janus kinase-2/signal transducer and activator of transcription-3(JAK2/STAT3),Bax/Bcl-2,and cleaved caspase-3.Therefore,this nanofiber membrane exhibits a neuroprotective effect on oxygen/glucose-deprived neurovascular units by inhibiting the JAK2/STAT3 pathway.展开更多
Exploration of advanced gel polymer electrolytes(GPEs)represents a viable strategy for mitigating dendritic lithium(Li)growth,which is crucial in ensuring the safe operation of high energy density Li metal batteries(L...Exploration of advanced gel polymer electrolytes(GPEs)represents a viable strategy for mitigating dendritic lithium(Li)growth,which is crucial in ensuring the safe operation of high energy density Li metal batteries(LMBs).Despite this,the application of GPEs is still hindered by inadequate ionic conductivity,low Li^(+)transference number,and subpar physicochemical properties.Herein,Ti O_(2-x)nanofibers(NF)with oxygen vacancy defects were synthesized by a one-step process as inorganic fillers to enhance the thermal/mechanical/ionic-transportation performances of composite GPEs.Various characterizations and theoretical calculations reveal that the oxygen vacancies on the surface of Ti O_(2-x)NF accelerate the dissociation of Li PF_6,promote the rapid transfer of free Li^(+),and influence the formation of Li F-enriched solid electrolyte interphase.Consequently,the composite GPEs demonstrate enhanced ionic conductivity(1.90m S cm^(-1)at room temperature),higher lithium-ion transference number(0.70),wider electrochemical stability window(5.50 V),superior mechanical strength,excellent thermal stability(210℃),and improved compatibility with lithium,resulting in superior cycling stability and rate performance in both Li||Li,Li||Li Fe PO_(4),and Li||Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2)cells.Overall,the synergistic influence of nanofiber morphology and enriched oxygen vacancy structure of fillers on electrochemical properties of composite GPEs is comprehensively investigated,thus,it is anticipated to shed new light on designing high-performance GPEs LMBs.展开更多
Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibe...Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibers/polypyrrole/nickel(APN)aerogels,which serve dual roles as both microwave absorbers and pressure sensors.In this work,we focused on the preparation of aramid nanofibers/polypyrrole(AP15)aerogels,where the mass ratio of aramid nanofibers to pyrrole was 1:5.We employed the oxidative polymerization method for the preparation process.Following this,nickel was thermally evaporated onto the surface of the AP15 aerogels,resulting in the creation of an ultralight(9.35 mg·cm^(-3)).This aerogel exhibited a porous structure.The introduction of nickel into the aerogel aimed to enhance magnetic loss and adjust impedance matching,thereby improving electromagnetic wave absorption performance.The minimum reflection loss value achieved was-48.7 dB,and the maximum effective absorption bandwidth spanned 8.42 GHz with a thickness of 2.9 mm.These impressive metrics can be attributed to the three-dimensional network porous structure of the aerogel and perfect impedance matching.Moreover,the use of aramid nanofibers and a three-dimensional hole structure endowed the APN aerogels with good insulation,flame-retardant properties,and compression resilience.Even under a compression strain of 50%,the aerogel maintained its resilience over 500 cycles.The incorporation of polypyrrole and nickel particles further enhanced the conductivity of the aerogel.Consequently,the final APN aerogel sensor demonstrated high sensitivity(10.78 kPa-1)and thermal stability.In conclusion,the APN aerogels hold significant promise as ultra-broadband microwave absorbers and pressure sensors.展开更多
Quantum light sources are the core resources for photonics-based quantum information processing.We investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversio...Quantum light sources are the core resources for photonics-based quantum information processing.We investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversion in micro/nanofiber.The phase mismatching at one-third pump frequency gives rise to non-degenerate photon triplets,the joint spectral intensity of which has an elliptical locus with a fixed eccentricity of√6/3.Therefore,we propose a frequency-division scheme to separate non-degenerate photon triplets into three channels with high heralding efficiency for the first time.Choosing an appropriate pump wavelength can compensate for the fabrication errors of micro/nanofiber and also generate narrowband,non-degenerate photon triplet sources with a high signal-to-noise ratio.Furthermore,the long-period micro/nanofiber grating introduces a new controllable degree of freedom to tailor phase matching,resulting from the periodic oscillation of dispersion.In this scheme,the wavelength of photon triplets can be flexibly tuned using quasi-phase matching.We study the generation of photon triplets from this novel perspective of spectrum engineering,and we believe that this work will accelerate the practical implementation of photon triplets in quantum information processing.展开更多
This work presents the development of hierarchical niobium pentoxide(Nb_(2)O_(5))-based composite nanofiber membranes for integrated adsorption and photocatalytic degradation of methylene blue(MB)pollutants from aqueo...This work presents the development of hierarchical niobium pentoxide(Nb_(2)O_(5))-based composite nanofiber membranes for integrated adsorption and photocatalytic degradation of methylene blue(MB)pollutants from aqueous solutions.The Nb_(2)O_(5) nanorods were vertically grown using a hydrothermal process on a base electrospun nanofibrous membrane made of polyacrylonitrile/polyvinylidene fluoride/ammonium niobate(V)oxalate hydrate(Nb_(2)O_(5)@PAN/PVDF/ANO).They were characterized using field-emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD)analysis,and Fourier transform infrared(FTIR)spectroscopy.These composite nanofibers possessed a narrow optical bandgap energy of 3.31 eV and demonstrated an MB degradation efficiency of 96%after 480 min contact time.The pseudo-first-order kinetic study was also conducted,in which Nb_(2)O_(5)@PAN/PVDF/ANO nanofibers have kinetic constant values of 1.29×10^(-2) min^(-1) and 0.30×10^(-2) min^(-1) for adsorption and photocatalytic degradation of MB aqueous solutions,respectively.These values are 17.7 and 7.8 times greater than those of PAN/PVDF/ANO nanofibers without Nb_(2)O_(5) nanostructures.Besides their outstanding photocatalytic performance,the developed membrane materials exhibit advantageous characteristics in recycling,which subsequently widen their practical use in environmental remediation applications.展开更多
Inspired by the Chinese Knotting weave structure,an electromagnetic interference(EMI)nanofiber composite membrane with a twill surface was prepared.Poly(vinyl alcohol-co-ethylene)(Pva-co-PE)nanofibers and twill nylon ...Inspired by the Chinese Knotting weave structure,an electromagnetic interference(EMI)nanofiber composite membrane with a twill surface was prepared.Poly(vinyl alcohol-co-ethylene)(Pva-co-PE)nanofibers and twill nylon fabric were used as the matrix and filter templates,respectively.A Pva-co-PEMXene/silver nanowire(Pva-co-PE-MXene/AgNW,PM_(x)Ag)membrane was successfully prepared using a template method.When the MXene/AgNW content was only 7.4 wt%(PM_(7.4)Ag),the EMI shielding efficiency(SE)of the composite membrane with the oblique twill structure on the surface was 103.9 dB and the surface twill structure improved the EMI by 38.5%.This result was attributed to the pre-interference of the oblique twill structure in the direction of the incident EM wave,which enhanced the probability of the electromagnetic waves randomly colliding with the MXene nanosheets.Simultaneously,the internal reflection and ohmic and resonance losses were enhanced.The PM_(7.4)Ag membrane with the twill structure exhibited both an outstanding tensile strength of 22.8 MPa and EMI SE/t of 3925.2 dB cm^(-1).Moreover,the PM_(x)Ag nanocomposite membranes demonstrated an excellent thermal management performance,hydrophobicity,non-flammability,and performance stability,which was demonstrated by an EMI SE of 97.3%in a high-temperature environment of 140℃.The successful preparation of surface-twill composite membranes makes it difficult to achieve both a low filler content and a high EMI SE in electromagnetic shielding materials.This strategy provides a new approach for preparing thin membranes with excellent EMI properties.展开更多
A lightweight flexible thermally stable composite is fabricated by com-bining silica nanofiber membranes(SNM)with MXene@c-MWCNT hybrid film.The flexible SNM with outstanding thermal insulation are prepared from tetrae...A lightweight flexible thermally stable composite is fabricated by com-bining silica nanofiber membranes(SNM)with MXene@c-MWCNT hybrid film.The flexible SNM with outstanding thermal insulation are prepared from tetraethyl orthosilicate hydrolysis and condensation by electrospinning and high-temperature calcination;the MXene@c-MWCNT_(x:y)films are prepared by vacuum filtration tech-nology.In particular,the SNM and MXene@c-MWCNT_(6:4)as one unit layer(SMC_(1))are bonded together with 5 wt%polyvinyl alcohol(PVA)solution,which exhibits low thermal conductivity(0.066 W m^(-1)K^(-1))and good electromagnetic interference(EMI)shielding performance(average EMI SE_(T),37.8 dB).With the increase in func-tional unit layer,the overall thermal insulation performance of the whole composite film(SMC_(x))remains stable,and EMI shielding performance is greatly improved,especially for SMC_(3)with three unit layers,the average EMI SET is as high as 55.4 dB.In addition,the organic combination of rigid SNM and tough MXene@c-MWCNT_(6:4)makes SMC_(x)exhibit good mechanical tensile strength.Importantly,SMC_(x)exhibit stable EMI shielding and excellent thermal insulation even in extreme heat and cold environment.Therefore,this work provides a novel design idea and important reference value for EMI shielding and thermal insulation components used in extreme environmental protection equipment in the future.展开更多
The unique characteristics of nanofibers in rational electrode design enable effec-tive utilization and maximizing material properties for achieving highly efficient and sustainable CO_(2) reduction reactions( CO_(2)R...The unique characteristics of nanofibers in rational electrode design enable effec-tive utilization and maximizing material properties for achieving highly efficient and sustainable CO_(2) reduction reactions( CO_(2)RRs)in solid oxide elec-trolysis cells(SOECs).However,practical appli-cation of nanofiber-based electrodes faces chal-lenges in establishing sufficient interfacial contact and adhesion with the dense electrolyte.To tackle this challenge,a novel hybrid nanofiber electrode,La_(0.6)Sr_(0.4)Co_(0.15)Fe_(0.8)Pd_(0.05)O_(3-δ)(H-LSCFP),is developed by strategically incorporating low aspect ratio crushed LSCFP nanofibers into the excess porous interspace of a high aspect ratio LSCFP nanofiber framework synthesized via electrospinning technique.After consecutive treatment in 100% H_(2) and CO_(2) at 700°C,LSCFP nanofibers form a perovskite phase with in situ exsolved Co metal nanocatalysts and a high concentration of oxygen species on the surface,enhancing CO_(2) adsorption.The SOEC with the H-LSCFP electrode yielded an outstanding current density of 2.2 A cm^(-2) in CO_(2) at 800°C and 1.5 V,setting a new benchmark among reported nanofiber-based electrodes.Digital twinning of the H-LSCFP reveals improved contact adhesion and increased reaction sites for CO_(2)RR.The present work demonstrates a highly catalytically active and robust nanofiber-based fuel electrode with a hybrid structure,paving the way for further advancements and nanofiber applications in CO_(2)-SOECs.展开更多
As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progres...As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented.展开更多
This study proposes a facile, but precise method to back-calculate the effective modulus of nanocomposite interleaving plies. Adaptation of a conventional dry-reinforcement resin film infusion (RFI) approach allows in...This study proposes a facile, but precise method to back-calculate the effective modulus of nanocomposite interleaving plies. Adaptation of a conventional dry-reinforcement resin film infusion (RFI) approach allows interleaving neat epoxy layers (NE) with the epoxy-infused nanofibrous plies (XE) of constant thickness. The final cured nanocomposite laminate thus has the form (NE/XE)n, where “n” denotes the number of the repeats and enables clear distinction of the nanocomposite interlayers through the thickness. Mechanical testing of neat epoxy and laminated nanocomposite specimens can be coupled with the classical lamination theory for back-calculating in-plane elastic modulus of the individual epoxy-infused nanofibrous plies (EXE). Finite element analysis (FEA) and testing the laminated nanocomposite subject to flexural loading (3-point bending) are proposed to validate the analytically back-calculated EXE. It is shown that the FEA prediction incorporating EXE and testing for flexural modulus of (NE/XE)20 laminated nanocomposites correlate well and the results are within 5%. This finding suggests that the back-calculation scheme reported herein would be attractive for accurately determining the properties of an individual nanocomposite building block layer. The proposed framework is beneficial for modelling laminated structural composites incorporating XE-like nanocomposite interlayers.展开更多
Highly dispersed bimetallic alloy nanoparticle electrocatalysts have been demonstrated to exhibit exceptional performance in driving the nitrate reduction reaction(NO_(3)RR)to generate ammonia(NH_(3)).In this study,we...Highly dispersed bimetallic alloy nanoparticle electrocatalysts have been demonstrated to exhibit exceptional performance in driving the nitrate reduction reaction(NO_(3)RR)to generate ammonia(NH_(3)).In this study,we prepared mesoporous carbon nanofibers(mCNFs)functionalized with ordered PtFe alloys(O-PtFe-mCNFs)by a composite micelle interface-induced co-assembly method using poly(ethylene oxide)-block-polystyrene(PEO-b-PS)as a template.When employed as electrocatalysts,O-PtFe-mCNFs exhibited superior electrocatalytic performance for the NO_(3RR)compared to the mCNFs functionalized with disordered PtFe alloys(D-PtFe-mCNFs).Notably,the NH_(3)production performance was particularly outstanding,with a maximum NH_(3)yield of up to 959.6μmol/(h·cm~2).Furthermore,the Faraday efficiency(FE)was even 88.0%at-0.4 V vs.reversible hydrogen electrode(RHE).This finding provides compelling evidence of the potential of ordered PtFe alloy catalysts for the electrocatalytic NO_(3)RR.展开更多
Application of novel radio technologies and equip-ment inevitably leads to electromagnetic pollution.One-dimensional polymer-based composite membrane structures have been shown to be an effective strategy to obtain hi...Application of novel radio technologies and equip-ment inevitably leads to electromagnetic pollution.One-dimensional polymer-based composite membrane structures have been shown to be an effective strategy to obtain high-performance microwave absorbers.Herein,we reported a one-dimensional N-doped carbon nanofibers material which encapsulated the hollow Co_(3)SnC_(0.7) nano-cubes in the fiber lumen by electrospinning.Space charge stacking formed between nanoparticles can be channeled by longitudinal fibrous structures.The dielectric constant of the fibers is highly related to the carbonization temperature,and the great impedance matching can be achieved by synergetic effect between Co_(3)SnC_(0.7) and carbon network.At 800℃,the necklace-like Co_(3)SnC_(0.7)/CNF with 5%low load achieves an excellent RL value of−51.2 dB at 2.3 mm and the effective absorption bandwidth of 7.44 GHz with matching thickness of 2.5 mm.The multiple electromagnetic wave(EMW)reflections and interfacial polarization between the fibers and the fibers internal contribute a major effect to attenuating the EMW.These strategies for regulating electromagnetic performance can be expanded to other electromagnetic functional materials which facilitate the development of emerging absorbers.展开更多
An efficient chamber-induced activation method was applied for the preparation of holey graphene/cellulose nanofiber-based film with high specific surface area(SSA)and multiple channels through the graphene nanosheets...An efficient chamber-induced activation method was applied for the preparation of holey graphene/cellulose nanofiber-based film with high specific surface area(SSA)and multiple channels through the graphene nanosheets.With the cellulose nanofiber(CNF)simultaneously serving as“dispersing agent,”“spacer,”and“activating agent,”the graphene oxide(GO)nanosheets are perforated by the pyrolysis gas from CNF in the confined space inside the hybrid films,uniformly dispersed,and sandwiched between CNF networks with less agglomeration and restacking.Additionally,we have proved that H2O and H2 are primarily responsible for the activation and etching of GO/CNF film.As the CNF content increases,the mesoporosity of the activated reduced GO/CNF(A-RGO/CNF)film increases,and the graphene nanosheets show more nanopore perforations.Benefitting from the high SSA,high density,moderate mesoporosity,and abundant channels for ion diffusion through the graphene nanosheets,the A-RGO/CNF film exhibits the highest specific capacitance of 323(236)F g^(−1)(F cm^(−3))at 1Ag^(−1).For the A-RGO5/CNF5 film containing half CNF and half GO,an excellent comprehensive electrochemical performance including superior rate performance(208(160)F g^(−1)(F cm^(−3))at 60Ag^(−1))is exhibited.Moreover,the A-RGO5/CNF5 electrode in an all-solid-state flexible symmetric supercapacitor delivers a high specific capacitance of 250(193)F g^(−1)(F cm^(−3))at 1Ag^(−1).This study provides a novel idea for the preparation of holey graphene-based film for supercapacitor electrodes.The strategy of simultaneously employing CNF as“dispersing agent,”“spacer,”and“activating agent”also offers a new vision for the assembly of homogeneous nanohybrid material and the utilization of pyrolysis gas.展开更多
Highly ordered and uniformly porous structure of conductive foams is a vital issue for various functional purposes such as piezoresistive sensing and electromagnetic interference(EMI) shielding. With the aids of Kevla...Highly ordered and uniformly porous structure of conductive foams is a vital issue for various functional purposes such as piezoresistive sensing and electromagnetic interference(EMI) shielding. With the aids of Kevlar polyanionic chains, thermoplastic polyurethane(TPU) foams reinforced by aramid nanofibers(ANF) with adjustable pore-size distribution were successfully obtained via a nonsolvent-induced phase separation. In this regard, the most outstanding result is the in situ formation of ANF in TPU foams after protonation of Kevlar polyanion during the NIPS process. Furthermore, in situ growth of copper nanoparticles(Cu NPs) on TPU/ANF foams was performed according to the electroless deposition by using the tiny amount of pre-blended Ti_(3)C_(2)T_(x) MXene as reducing agents. Particularly, the existence of Cu NPs layers significantly promoted the storage modulus in 2,932% increments, and the well-designed TPU/ANF/Ti_(3)C_(2)T_(x) MXene(PAM-Cu) composite foams showed distinguished compressive cycle stability. Taking virtues of the highly ordered and elastic porous architectures, the PAM-Cu foams were utilized as piezoresistive sensor exhibiting board compressive interval of 0–344.5 kPa(50% strain) with good sensitivity at 0.46 kPa^(-1). Meanwhile,the PAM-Cu foams displayed remarkable EMI shielding effectiveness at 79.09 dB in X band. This work provides an ideal strategy to fabricate highly ordered TPU foams with outstanding elastic recovery and excellent EMI shielding performance, which can be used as a promising candidate in integration of satisfactory piezoresistive sensor and EMI shielding applications for human–machine interfaces.展开更多
The rational synergy of chemical composition and spatial nanostructures of electrode materials play important roles in high-performance energy storage devices.Here,we designed pea-like MoS_(2)@NiS_(1.03)-carbon hollow...The rational synergy of chemical composition and spatial nanostructures of electrode materials play important roles in high-performance energy storage devices.Here,we designed pea-like MoS_(2)@NiS_(1.03)-carbon hollow nanofibers using a simple electrospinning and thermal treatment method.The hierarchical hollow nanofiber is composed of a nitrogen-doped carbon-coated NiS_(1.03) tube wall,in which pea-like uniformly discrete MoS_(2) nanoparticles are enclosed.As a sodium-ion battery electrode material,the MoS_(2)@NiS_(1.03)-carbon hollow nanofibers have abundant diphasic heterointerfaces,a conductive network,and appropriate volume variation-buffering spaces,which can facilitate ion diffusion kinetics,shorten the diffusion path of electrons/ion,and buffer volume expansion during Na^(+)insertion/extraction.It shows outstanding rate capacity and long-cycle performance in a sodium-ion battery.This heterogeneous hollow nanoarchitectures designing enlightens an efficacious strategy to boost the capacity and long-life stability of sodium storage performance of electrode materials.展开更多
Flexible and stretchable transparent electrodes are widely used in smart display,energy,wearable devices and other fields.Due to the limitations of flexibility and stretchability of indium tin oxide electrodes,alterna...Flexible and stretchable transparent electrodes are widely used in smart display,energy,wearable devices and other fields.Due to the limitations of flexibility and stretchability of indium tin oxide electrodes,alternative electrodes have appeared,such as metal films,metal nanowires,and conductive meshes.However,few of the above electrodes can simultaneously have excellent flexibility,stretchability,and optoelectronic properties.Nanofiber(NF),a continuous ultra-long one-dimensional conductive material,is considered to be one of the ideal materials for high-performance transparent electrodes with excellent properties due to its unique structure.This paper summarizes the important research progress of NF flexible transparent electrodes(FTEs)in recent years from the aspects of NF electrode materials,preparation technology and application.First,the unique advantages and limitations of various NF materials are systematically discussed.Then,we summarize the preparation technology of various advanced NF FTEs,and point out the future development trend.We also discuss the application of NFs in solar cells,supercapacitors,electric heating equipments,sensors,etc,and analyze its development potential in flexible electronic equipment,as well as problems that need to be solved.Finally,the challenges and future development trends are proposed in the wide application of NF FTEs in the field of flexible optoelectronics.展开更多
Carbon nanofiber(CNF)was widely utilized in the field of electrochemical energy storage due to its superiority of conductivity and mechanics.However,CNF was generally prepared at relatively high temperature.Herein,nit...Carbon nanofiber(CNF)was widely utilized in the field of electrochemical energy storage due to its superiority of conductivity and mechanics.However,CNF was generally prepared at relatively high temperature.Herein,nitrogen-doped hard carbon nanofibers(NHCNFs)were prepared by a lowtemperature carbonization treatment assisted with electrospinning technology.Density functional theory analysis elucidates the incorporation of nitrogen heteroatoms with various chemical states into carbon matrix would significantly alter the total electronic configurations,leading to the robust adsorption and efficient diffusion of Na atoms on electrode interface.The obtained material carbonized at 600°C(NHCNF-600)presented a reversible specific capacity of 191.0 mAh g^(−1)and no capacity decay after 200 cycles at 1 A g^(−1).It was found that the sodium-intercalated degree had a correlation with the electrochemical impedance.A sodium-intercalated potential of 0.2 V was adopted to lower the electrochemical impedance.The constructed sodium-ion capacitor with activated carbon cathode and presodiated NHCNF-600 anode can present an energy power density of 82.1 Wh kg^(−1)and a power density of 7.0 kW kg^(−1).展开更多
Hydrogen sulfide(H_(2)S)is an industrial exhausted gas that is highly toxic to humans and the environment.Combining desulfurization and fabrication of cathode materials for lithium-sulfur batteries(LSBs)can solve this...Hydrogen sulfide(H_(2)S)is an industrial exhausted gas that is highly toxic to humans and the environment.Combining desulfurization and fabrication of cathode materials for lithium-sulfur batteries(LSBs)can solve this issue with a double benefit.Herein,the amino-functionalized lotus root-like carbon nanofibers(NH_(2)-PLCNFs)are prepared by the amination of electrospinning carbon nanofibers under dielectric barrier discharge plasma.Selective catalytic oxidation of H_(2)S to elemental sulfur(S)is achieved over the metalfree NH_(2)-PLCNFs catalyst,and the obtained composite S@NH_(2)-PLCNFs is further used as cathode in LSBs.NH_(2)-PLCNFs enable efficient desulfurization(removal capacity as high as 3.46 g H_(2)S g^(−1) catalyst)and strongly covalent stabilization of S on modified carbon nanofibers.LSBs equipped with S@NH_(2)-PLCNFs deliver a high specific capacity of 705.8 mA h g^(−1) at 1 C after 1000 cycles based on the spatial confinement and the covalent stabilization of electroactive materials on amino-functionalized porous carbon matrix.It is revealed that S@NH_(2)-PLCNFs obtained by this kind of chemical vapor deposition leads to a more homogeneous S distribution and superior electrochemical performance to the sample S/NH_(2)-PLCNF-M prepared by the traditional molten infusion.This work opens a new avenue for the combination of environment protection and energy storage.展开更多
OER catalyst of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C(NiFeSC series)mixed crystal composite nanofibers was prepared by electrospinning and atmospheric heat treatment process.The testing results indicate that the diameters of Ni_(...OER catalyst of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C(NiFeSC series)mixed crystal composite nanofibers was prepared by electrospinning and atmospheric heat treatment process.The testing results indicate that the diameters of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C composite nanofibers is about 200 nm,the grains size is about 1-3 nm,and the fiber surface is rough.The electrochemical test results show that the heterojunction of the prepared Ni_(3)Fe/Ni_(4)S_(3)/Ni/C hybrid crystal composite nanofiber has synergistic effect with sulfide,and exhibits good electrocatalytic activity of water decomposition and OER in alkaline system.The OER electrocatalytic performance of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C composite electrode prepared via a heat treatment at 1000℃process was tested in 1 mol/L KOH electrolytes.The results show that the overpotential is about 298 mV,the Tafel slope is about 74 mV?dec-1,and the surface resistance is about 1.69Ω·cm^(2),at the current density of 10 mA·cm^(-2).展开更多
A high performance preoxidized poly(acrylonitrile)(O-PAN)nanofiber membrane with excellent solvent resistance,thermal stability and flexibility was fabricated by the preoxidation of electrospun PAN nanofiber membrane....A high performance preoxidized poly(acrylonitrile)(O-PAN)nanofiber membrane with excellent solvent resistance,thermal stability and flexibility was fabricated by the preoxidation of electrospun PAN nanofiber membrane.The performance of resultant O-PAN nanofiber membrane was optimized by altering the PAN concentration and preoxidation temperature.The results showed that the O-PAN nanofiber membrane which made from PAN concentration of 14%(mass)and preoxidation temperature of 250.0℃ have a more optimal comprehensive performance.In the long-term separation test of SiO2 particle(1 μm)in DMAc suspension,the permeate flux of O-PAN nanofiber membrane stabilized at 227.91 L·m^(-2)·h^(-1)(25℃,0.05 MPa)while the SiO2 rejection above 99.6%,which showed excellent solvent resistance and separation performance.In order to further explore the application of the O-PAN nanofiber membrane,the OPAN nanofiber membrane was treated with fluoride and used in oil/water separation process.The O-PAN nanofiber membrane after hydrophobic treatment showed excellent hydrophobicity and good oil/water separation performance with the permeate flux about 969.59 L·m^(-2)·h^(-1)while the separation efficiency above 96.1%.The O-PAN nanofiber membrane exhibited a potential application prospect in harsh environment separation.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81974207(to JH),82001383(to DW)the Special Clinical Research Project of Health Profession of Shanghai Municipal Health Commission,No.20204Y0076(to DW)。
文摘Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell proliferation and differentiation,thereby exerting neuroprotective effects.However,the beneficial effects of endogenous VEGFA/b FGF are limited as their expression is only transiently increased.In this study,we generated multilayered nanofiber membranes loaded with VEGFA/b FGF using layer-by-layer self-assembly and electrospinning techniques.We found that a membrane containing 10 layers had an ideal ultrastructure and could efficiently and stably release growth factors for more than 1 month.This 10-layered nanofiber membrane promoted brain microvascular endothelial cell tube formation and proliferation,inhibited neuronal apoptosis,upregulated the expression of tight junction proteins,and improved the viability of various cellular components of neurovascular units under conditions of oxygen/glucose deprivation.Furthermore,this nanofiber membrane decreased the expression of Janus kinase-2/signal transducer and activator of transcription-3(JAK2/STAT3),Bax/Bcl-2,and cleaved caspase-3.Therefore,this nanofiber membrane exhibits a neuroprotective effect on oxygen/glucose-deprived neurovascular units by inhibiting the JAK2/STAT3 pathway.
基金supported by the National Natural Science Foundation of China(52122702,52277215)the Natural Science Foundation of Heilongjiang Province of China(JQ2021E005)。
文摘Exploration of advanced gel polymer electrolytes(GPEs)represents a viable strategy for mitigating dendritic lithium(Li)growth,which is crucial in ensuring the safe operation of high energy density Li metal batteries(LMBs).Despite this,the application of GPEs is still hindered by inadequate ionic conductivity,low Li^(+)transference number,and subpar physicochemical properties.Herein,Ti O_(2-x)nanofibers(NF)with oxygen vacancy defects were synthesized by a one-step process as inorganic fillers to enhance the thermal/mechanical/ionic-transportation performances of composite GPEs.Various characterizations and theoretical calculations reveal that the oxygen vacancies on the surface of Ti O_(2-x)NF accelerate the dissociation of Li PF_6,promote the rapid transfer of free Li^(+),and influence the formation of Li F-enriched solid electrolyte interphase.Consequently,the composite GPEs demonstrate enhanced ionic conductivity(1.90m S cm^(-1)at room temperature),higher lithium-ion transference number(0.70),wider electrochemical stability window(5.50 V),superior mechanical strength,excellent thermal stability(210℃),and improved compatibility with lithium,resulting in superior cycling stability and rate performance in both Li||Li,Li||Li Fe PO_(4),and Li||Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2)cells.Overall,the synergistic influence of nanofiber morphology and enriched oxygen vacancy structure of fillers on electrochemical properties of composite GPEs is comprehensively investigated,thus,it is anticipated to shed new light on designing high-performance GPEs LMBs.
基金The authors acknowledge the financial support from the National Natural Science Foundation of China(Nos.52071280 and 51972280)the Natural Science Foundation of Hebei Province,China(Nos.E2020203151 and E2022203208)+1 种基金the Research Program of the College Science&Technology of Hebei Province,China(No.ZD2020121)the Cultivation Project for Basic Research and Innovation of Yanshan University,China(No.2021LGZD016).
文摘Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibers/polypyrrole/nickel(APN)aerogels,which serve dual roles as both microwave absorbers and pressure sensors.In this work,we focused on the preparation of aramid nanofibers/polypyrrole(AP15)aerogels,where the mass ratio of aramid nanofibers to pyrrole was 1:5.We employed the oxidative polymerization method for the preparation process.Following this,nickel was thermally evaporated onto the surface of the AP15 aerogels,resulting in the creation of an ultralight(9.35 mg·cm^(-3)).This aerogel exhibited a porous structure.The introduction of nickel into the aerogel aimed to enhance magnetic loss and adjust impedance matching,thereby improving electromagnetic wave absorption performance.The minimum reflection loss value achieved was-48.7 dB,and the maximum effective absorption bandwidth spanned 8.42 GHz with a thickness of 2.9 mm.These impressive metrics can be attributed to the three-dimensional network porous structure of the aerogel and perfect impedance matching.Moreover,the use of aramid nanofibers and a three-dimensional hole structure endowed the APN aerogels with good insulation,flame-retardant properties,and compression resilience.Even under a compression strain of 50%,the aerogel maintained its resilience over 500 cycles.The incorporation of polypyrrole and nickel particles further enhanced the conductivity of the aerogel.Consequently,the final APN aerogel sensor demonstrated high sensitivity(10.78 kPa-1)and thermal stability.In conclusion,the APN aerogels hold significant promise as ultra-broadband microwave absorbers and pressure sensors.
基金Project supported by the National Natural Science Foundation of China(Grant No.61605249)the Science and Technology Key Project of Henan Province of China(Grant Nos.182102210577 and 232102211086).
文摘Quantum light sources are the core resources for photonics-based quantum information processing.We investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversion in micro/nanofiber.The phase mismatching at one-third pump frequency gives rise to non-degenerate photon triplets,the joint spectral intensity of which has an elliptical locus with a fixed eccentricity of√6/3.Therefore,we propose a frequency-division scheme to separate non-degenerate photon triplets into three channels with high heralding efficiency for the first time.Choosing an appropriate pump wavelength can compensate for the fabrication errors of micro/nanofiber and also generate narrowband,non-degenerate photon triplet sources with a high signal-to-noise ratio.Furthermore,the long-period micro/nanofiber grating introduces a new controllable degree of freedom to tailor phase matching,resulting from the periodic oscillation of dispersion.In this scheme,the wavelength of photon triplets can be flexibly tuned using quasi-phase matching.We study the generation of photon triplets from this novel perspective of spectrum engineering,and we believe that this work will accelerate the practical implementation of photon triplets in quantum information processing.
基金funded by the Minister of Education,Culture,Research,and Technology of Indonesia through a research scheme of“Penelitian Fundamental–Reguler(PFR)2023”under a contract number of 1115c/IT9.2.1/PT.01.03/2023.
文摘This work presents the development of hierarchical niobium pentoxide(Nb_(2)O_(5))-based composite nanofiber membranes for integrated adsorption and photocatalytic degradation of methylene blue(MB)pollutants from aqueous solutions.The Nb_(2)O_(5) nanorods were vertically grown using a hydrothermal process on a base electrospun nanofibrous membrane made of polyacrylonitrile/polyvinylidene fluoride/ammonium niobate(V)oxalate hydrate(Nb_(2)O_(5)@PAN/PVDF/ANO).They were characterized using field-emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD)analysis,and Fourier transform infrared(FTIR)spectroscopy.These composite nanofibers possessed a narrow optical bandgap energy of 3.31 eV and demonstrated an MB degradation efficiency of 96%after 480 min contact time.The pseudo-first-order kinetic study was also conducted,in which Nb_(2)O_(5)@PAN/PVDF/ANO nanofibers have kinetic constant values of 1.29×10^(-2) min^(-1) and 0.30×10^(-2) min^(-1) for adsorption and photocatalytic degradation of MB aqueous solutions,respectively.These values are 17.7 and 7.8 times greater than those of PAN/PVDF/ANO nanofibers without Nb_(2)O_(5) nanostructures.Besides their outstanding photocatalytic performance,the developed membrane materials exhibit advantageous characteristics in recycling,which subsequently widen their practical use in environmental remediation applications.
基金supported by the National Natural Science Foundation of China(12205225,52373063,and 51873166)。
文摘Inspired by the Chinese Knotting weave structure,an electromagnetic interference(EMI)nanofiber composite membrane with a twill surface was prepared.Poly(vinyl alcohol-co-ethylene)(Pva-co-PE)nanofibers and twill nylon fabric were used as the matrix and filter templates,respectively.A Pva-co-PEMXene/silver nanowire(Pva-co-PE-MXene/AgNW,PM_(x)Ag)membrane was successfully prepared using a template method.When the MXene/AgNW content was only 7.4 wt%(PM_(7.4)Ag),the EMI shielding efficiency(SE)of the composite membrane with the oblique twill structure on the surface was 103.9 dB and the surface twill structure improved the EMI by 38.5%.This result was attributed to the pre-interference of the oblique twill structure in the direction of the incident EM wave,which enhanced the probability of the electromagnetic waves randomly colliding with the MXene nanosheets.Simultaneously,the internal reflection and ohmic and resonance losses were enhanced.The PM_(7.4)Ag membrane with the twill structure exhibited both an outstanding tensile strength of 22.8 MPa and EMI SE/t of 3925.2 dB cm^(-1).Moreover,the PM_(x)Ag nanocomposite membranes demonstrated an excellent thermal management performance,hydrophobicity,non-flammability,and performance stability,which was demonstrated by an EMI SE of 97.3%in a high-temperature environment of 140℃.The successful preparation of surface-twill composite membranes makes it difficult to achieve both a low filler content and a high EMI SE in electromagnetic shielding materials.This strategy provides a new approach for preparing thin membranes with excellent EMI properties.
基金the China Scholarship Council(2021)the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FPEJ-2024-249-03”.
文摘A lightweight flexible thermally stable composite is fabricated by com-bining silica nanofiber membranes(SNM)with MXene@c-MWCNT hybrid film.The flexible SNM with outstanding thermal insulation are prepared from tetraethyl orthosilicate hydrolysis and condensation by electrospinning and high-temperature calcination;the MXene@c-MWCNT_(x:y)films are prepared by vacuum filtration tech-nology.In particular,the SNM and MXene@c-MWCNT_(6:4)as one unit layer(SMC_(1))are bonded together with 5 wt%polyvinyl alcohol(PVA)solution,which exhibits low thermal conductivity(0.066 W m^(-1)K^(-1))and good electromagnetic interference(EMI)shielding performance(average EMI SE_(T),37.8 dB).With the increase in func-tional unit layer,the overall thermal insulation performance of the whole composite film(SMC_(x))remains stable,and EMI shielding performance is greatly improved,especially for SMC_(3)with three unit layers,the average EMI SET is as high as 55.4 dB.In addition,the organic combination of rigid SNM and tough MXene@c-MWCNT_(6:4)makes SMC_(x)exhibit good mechanical tensile strength.Importantly,SMC_(x)exhibit stable EMI shielding and excellent thermal insulation even in extreme heat and cold environment.Therefore,this work provides a novel design idea and important reference value for EMI shielding and thermal insulation components used in extreme environmental protection equipment in the future.
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korean Government(MSIT)(2019M3E6A1103944,2020R1A2C2010690).
文摘The unique characteristics of nanofibers in rational electrode design enable effec-tive utilization and maximizing material properties for achieving highly efficient and sustainable CO_(2) reduction reactions( CO_(2)RRs)in solid oxide elec-trolysis cells(SOECs).However,practical appli-cation of nanofiber-based electrodes faces chal-lenges in establishing sufficient interfacial contact and adhesion with the dense electrolyte.To tackle this challenge,a novel hybrid nanofiber electrode,La_(0.6)Sr_(0.4)Co_(0.15)Fe_(0.8)Pd_(0.05)O_(3-δ)(H-LSCFP),is developed by strategically incorporating low aspect ratio crushed LSCFP nanofibers into the excess porous interspace of a high aspect ratio LSCFP nanofiber framework synthesized via electrospinning technique.After consecutive treatment in 100% H_(2) and CO_(2) at 700°C,LSCFP nanofibers form a perovskite phase with in situ exsolved Co metal nanocatalysts and a high concentration of oxygen species on the surface,enhancing CO_(2) adsorption.The SOEC with the H-LSCFP electrode yielded an outstanding current density of 2.2 A cm^(-2) in CO_(2) at 800°C and 1.5 V,setting a new benchmark among reported nanofiber-based electrodes.Digital twinning of the H-LSCFP reveals improved contact adhesion and increased reaction sites for CO_(2)RR.The present work demonstrates a highly catalytically active and robust nanofiber-based fuel electrode with a hybrid structure,paving the way for further advancements and nanofiber applications in CO_(2)-SOECs.
基金financial supports from the National Natural Science Foundation of China(No.61975173)the Key Research and Development Project of Zhejiang Province(No.2022C03103,2023C01045).
文摘As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented.
文摘This study proposes a facile, but precise method to back-calculate the effective modulus of nanocomposite interleaving plies. Adaptation of a conventional dry-reinforcement resin film infusion (RFI) approach allows interleaving neat epoxy layers (NE) with the epoxy-infused nanofibrous plies (XE) of constant thickness. The final cured nanocomposite laminate thus has the form (NE/XE)n, where “n” denotes the number of the repeats and enables clear distinction of the nanocomposite interlayers through the thickness. Mechanical testing of neat epoxy and laminated nanocomposite specimens can be coupled with the classical lamination theory for back-calculating in-plane elastic modulus of the individual epoxy-infused nanofibrous plies (EXE). Finite element analysis (FEA) and testing the laminated nanocomposite subject to flexural loading (3-point bending) are proposed to validate the analytically back-calculated EXE. It is shown that the FEA prediction incorporating EXE and testing for flexural modulus of (NE/XE)20 laminated nanocomposites correlate well and the results are within 5%. This finding suggests that the back-calculation scheme reported herein would be attractive for accurately determining the properties of an individual nanocomposite building block layer. The proposed framework is beneficial for modelling laminated structural composites incorporating XE-like nanocomposite interlayers.
基金National Natural Science Foundation of China(Nos.52225204,52173233 and 52202085)Innovation Program of Shanghai Municipal Education Commission,China(No.2021-01-07-00-03-E00109)+3 种基金Natural Science Foundation of Shanghai,China(No.23ZR1479200)“Shuguang Program”Supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission,China(No.20SG33)Fundamental Research Funds for the Central Universities,China(No.2232024Y-01)DHU Distinguished Young Professor Program,China(Nos.LZA2022001 and LZB2023002)。
文摘Highly dispersed bimetallic alloy nanoparticle electrocatalysts have been demonstrated to exhibit exceptional performance in driving the nitrate reduction reaction(NO_(3)RR)to generate ammonia(NH_(3)).In this study,we prepared mesoporous carbon nanofibers(mCNFs)functionalized with ordered PtFe alloys(O-PtFe-mCNFs)by a composite micelle interface-induced co-assembly method using poly(ethylene oxide)-block-polystyrene(PEO-b-PS)as a template.When employed as electrocatalysts,O-PtFe-mCNFs exhibited superior electrocatalytic performance for the NO_(3RR)compared to the mCNFs functionalized with disordered PtFe alloys(D-PtFe-mCNFs).Notably,the NH_(3)production performance was particularly outstanding,with a maximum NH_(3)yield of up to 959.6μmol/(h·cm~2).Furthermore,the Faraday efficiency(FE)was even 88.0%at-0.4 V vs.reversible hydrogen electrode(RHE).This finding provides compelling evidence of the potential of ordered PtFe alloy catalysts for the electrocatalytic NO_(3)RR.
基金financially supported by the Natural Science Foundation of Shandong Province (No. ZR2019YQ24)Taishan Scholars and Young Experts Program of Shandong Province (No.tsqn202103057)+1 种基金the Qingchuang Talents Induction Program of Shandong Higher Education Institution (Research and Innovation Team of Structural-Functional Polymer Composites)Special Financial of Shandong Province (Structural Design of High-efficiency Electromagnetic Wave-absorbing Composite Materials and Construction of Shandong Provincial Talent Teams)
文摘Application of novel radio technologies and equip-ment inevitably leads to electromagnetic pollution.One-dimensional polymer-based composite membrane structures have been shown to be an effective strategy to obtain high-performance microwave absorbers.Herein,we reported a one-dimensional N-doped carbon nanofibers material which encapsulated the hollow Co_(3)SnC_(0.7) nano-cubes in the fiber lumen by electrospinning.Space charge stacking formed between nanoparticles can be channeled by longitudinal fibrous structures.The dielectric constant of the fibers is highly related to the carbonization temperature,and the great impedance matching can be achieved by synergetic effect between Co_(3)SnC_(0.7) and carbon network.At 800℃,the necklace-like Co_(3)SnC_(0.7)/CNF with 5%low load achieves an excellent RL value of−51.2 dB at 2.3 mm and the effective absorption bandwidth of 7.44 GHz with matching thickness of 2.5 mm.The multiple electromagnetic wave(EMW)reflections and interfacial polarization between the fibers and the fibers internal contribute a major effect to attenuating the EMW.These strategies for regulating electromagnetic performance can be expanded to other electromagnetic functional materials which facilitate the development of emerging absorbers.
基金funded by the Ministry of Business,Innovation and Employment Endeavour Fund of New Zealand(MAUX1801)supported by the China Postdoctoral Science Foundation(2021M692622).
文摘An efficient chamber-induced activation method was applied for the preparation of holey graphene/cellulose nanofiber-based film with high specific surface area(SSA)and multiple channels through the graphene nanosheets.With the cellulose nanofiber(CNF)simultaneously serving as“dispersing agent,”“spacer,”and“activating agent,”the graphene oxide(GO)nanosheets are perforated by the pyrolysis gas from CNF in the confined space inside the hybrid films,uniformly dispersed,and sandwiched between CNF networks with less agglomeration and restacking.Additionally,we have proved that H2O and H2 are primarily responsible for the activation and etching of GO/CNF film.As the CNF content increases,the mesoporosity of the activated reduced GO/CNF(A-RGO/CNF)film increases,and the graphene nanosheets show more nanopore perforations.Benefitting from the high SSA,high density,moderate mesoporosity,and abundant channels for ion diffusion through the graphene nanosheets,the A-RGO/CNF film exhibits the highest specific capacitance of 323(236)F g^(−1)(F cm^(−3))at 1Ag^(−1).For the A-RGO5/CNF5 film containing half CNF and half GO,an excellent comprehensive electrochemical performance including superior rate performance(208(160)F g^(−1)(F cm^(−3))at 60Ag^(−1))is exhibited.Moreover,the A-RGO5/CNF5 electrode in an all-solid-state flexible symmetric supercapacitor delivers a high specific capacitance of 250(193)F g^(−1)(F cm^(−3))at 1Ag^(−1).This study provides a novel idea for the preparation of holey graphene-based film for supercapacitor electrodes.The strategy of simultaneously employing CNF as“dispersing agent,”“spacer,”and“activating agent”also offers a new vision for the assembly of homogeneous nanohybrid material and the utilization of pyrolysis gas.
基金financially sponsored by the Science and Technology Commission of Shanghai Municipality (20230742300 and 18595800700)Key Laboratory of Resource Chemistry, Ministry of Education (KLRC_ME2103)the project of “joint assignment” in Shanghai University led by Prof. Tongyue Gao from School of Mechatronic Engineering and Automation。
文摘Highly ordered and uniformly porous structure of conductive foams is a vital issue for various functional purposes such as piezoresistive sensing and electromagnetic interference(EMI) shielding. With the aids of Kevlar polyanionic chains, thermoplastic polyurethane(TPU) foams reinforced by aramid nanofibers(ANF) with adjustable pore-size distribution were successfully obtained via a nonsolvent-induced phase separation. In this regard, the most outstanding result is the in situ formation of ANF in TPU foams after protonation of Kevlar polyanion during the NIPS process. Furthermore, in situ growth of copper nanoparticles(Cu NPs) on TPU/ANF foams was performed according to the electroless deposition by using the tiny amount of pre-blended Ti_(3)C_(2)T_(x) MXene as reducing agents. Particularly, the existence of Cu NPs layers significantly promoted the storage modulus in 2,932% increments, and the well-designed TPU/ANF/Ti_(3)C_(2)T_(x) MXene(PAM-Cu) composite foams showed distinguished compressive cycle stability. Taking virtues of the highly ordered and elastic porous architectures, the PAM-Cu foams were utilized as piezoresistive sensor exhibiting board compressive interval of 0–344.5 kPa(50% strain) with good sensitivity at 0.46 kPa^(-1). Meanwhile,the PAM-Cu foams displayed remarkable EMI shielding effectiveness at 79.09 dB in X band. This work provides an ideal strategy to fabricate highly ordered TPU foams with outstanding elastic recovery and excellent EMI shielding performance, which can be used as a promising candidate in integration of satisfactory piezoresistive sensor and EMI shielding applications for human–machine interfaces.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.22175007,21975007,52172080,and 22005012)the National Natural Science Foundation for Outstanding Youth Foundation,the Fundamental Research Funds for the Central Universities,the National Program for Support of Top-notch Young Professionalsthe 111 project(Grant No.B14009).
文摘The rational synergy of chemical composition and spatial nanostructures of electrode materials play important roles in high-performance energy storage devices.Here,we designed pea-like MoS_(2)@NiS_(1.03)-carbon hollow nanofibers using a simple electrospinning and thermal treatment method.The hierarchical hollow nanofiber is composed of a nitrogen-doped carbon-coated NiS_(1.03) tube wall,in which pea-like uniformly discrete MoS_(2) nanoparticles are enclosed.As a sodium-ion battery electrode material,the MoS_(2)@NiS_(1.03)-carbon hollow nanofibers have abundant diphasic heterointerfaces,a conductive network,and appropriate volume variation-buffering spaces,which can facilitate ion diffusion kinetics,shorten the diffusion path of electrons/ion,and buffer volume expansion during Na^(+)insertion/extraction.It shows outstanding rate capacity and long-cycle performance in a sodium-ion battery.This heterogeneous hollow nanoarchitectures designing enlightens an efficacious strategy to boost the capacity and long-life stability of sodium storage performance of electrode materials.
基金supported by the National Natural Science Foundation of China(Grant No.52175331)the Support plan for Outstanding Youth Innovation Team in Universities of Shandong Province,China(Grand No.2020KJB003)Natural Science Foundation of Shandong Province,China(Granted Nos.ZR2022ME014,ZR2021ME139 and ZR2020ZD04)。
文摘Flexible and stretchable transparent electrodes are widely used in smart display,energy,wearable devices and other fields.Due to the limitations of flexibility and stretchability of indium tin oxide electrodes,alternative electrodes have appeared,such as metal films,metal nanowires,and conductive meshes.However,few of the above electrodes can simultaneously have excellent flexibility,stretchability,and optoelectronic properties.Nanofiber(NF),a continuous ultra-long one-dimensional conductive material,is considered to be one of the ideal materials for high-performance transparent electrodes with excellent properties due to its unique structure.This paper summarizes the important research progress of NF flexible transparent electrodes(FTEs)in recent years from the aspects of NF electrode materials,preparation technology and application.First,the unique advantages and limitations of various NF materials are systematically discussed.Then,we summarize the preparation technology of various advanced NF FTEs,and point out the future development trend.We also discuss the application of NFs in solar cells,supercapacitors,electric heating equipments,sensors,etc,and analyze its development potential in flexible electronic equipment,as well as problems that need to be solved.Finally,the challenges and future development trends are proposed in the wide application of NF FTEs in the field of flexible optoelectronics.
基金supported by the National Natural Science Foundation of China(No.51907193,51822706,and 51777200)the Key Research Program of Frontier Sciences,CAS(No.ZDBS-LY-JSC047)the Youth Innovation Promotion Association,CAS(No.2020145)
文摘Carbon nanofiber(CNF)was widely utilized in the field of electrochemical energy storage due to its superiority of conductivity and mechanics.However,CNF was generally prepared at relatively high temperature.Herein,nitrogen-doped hard carbon nanofibers(NHCNFs)were prepared by a lowtemperature carbonization treatment assisted with electrospinning technology.Density functional theory analysis elucidates the incorporation of nitrogen heteroatoms with various chemical states into carbon matrix would significantly alter the total electronic configurations,leading to the robust adsorption and efficient diffusion of Na atoms on electrode interface.The obtained material carbonized at 600°C(NHCNF-600)presented a reversible specific capacity of 191.0 mAh g^(−1)and no capacity decay after 200 cycles at 1 A g^(−1).It was found that the sodium-intercalated degree had a correlation with the electrochemical impedance.A sodium-intercalated potential of 0.2 V was adopted to lower the electrochemical impedance.The constructed sodium-ion capacitor with activated carbon cathode and presodiated NHCNF-600 anode can present an energy power density of 82.1 Wh kg^(−1)and a power density of 7.0 kW kg^(−1).
基金financial support from projects funded by the National Natural Science Foundation of China(22179017,52172038).
文摘Hydrogen sulfide(H_(2)S)is an industrial exhausted gas that is highly toxic to humans and the environment.Combining desulfurization and fabrication of cathode materials for lithium-sulfur batteries(LSBs)can solve this issue with a double benefit.Herein,the amino-functionalized lotus root-like carbon nanofibers(NH_(2)-PLCNFs)are prepared by the amination of electrospinning carbon nanofibers under dielectric barrier discharge plasma.Selective catalytic oxidation of H_(2)S to elemental sulfur(S)is achieved over the metalfree NH_(2)-PLCNFs catalyst,and the obtained composite S@NH_(2)-PLCNFs is further used as cathode in LSBs.NH_(2)-PLCNFs enable efficient desulfurization(removal capacity as high as 3.46 g H_(2)S g^(−1) catalyst)and strongly covalent stabilization of S on modified carbon nanofibers.LSBs equipped with S@NH_(2)-PLCNFs deliver a high specific capacity of 705.8 mA h g^(−1) at 1 C after 1000 cycles based on the spatial confinement and the covalent stabilization of electroactive materials on amino-functionalized porous carbon matrix.It is revealed that S@NH_(2)-PLCNFs obtained by this kind of chemical vapor deposition leads to a more homogeneous S distribution and superior electrochemical performance to the sample S/NH_(2)-PLCNF-M prepared by the traditional molten infusion.This work opens a new avenue for the combination of environment protection and energy storage.
基金Funded by the Doctoral Fund of Chengdu University (2081919131)the Open Fund of Material Corrosion and Protection Key Laboratory of Sichuan Province (2021CL27)the Sichuan Science and Technology Program (2023YFG0229)。
文摘OER catalyst of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C(NiFeSC series)mixed crystal composite nanofibers was prepared by electrospinning and atmospheric heat treatment process.The testing results indicate that the diameters of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C composite nanofibers is about 200 nm,the grains size is about 1-3 nm,and the fiber surface is rough.The electrochemical test results show that the heterojunction of the prepared Ni_(3)Fe/Ni_(4)S_(3)/Ni/C hybrid crystal composite nanofiber has synergistic effect with sulfide,and exhibits good electrocatalytic activity of water decomposition and OER in alkaline system.The OER electrocatalytic performance of Ni_(3)Fe/Ni_(4)S_(3)/Ni/C composite electrode prepared via a heat treatment at 1000℃process was tested in 1 mol/L KOH electrolytes.The results show that the overpotential is about 298 mV,the Tafel slope is about 74 mV?dec-1,and the surface resistance is about 1.69Ω·cm^(2),at the current density of 10 mA·cm^(-2).
基金supported by the Science and Technology Plans of Tianjin(18PTSYJC00170)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(YESS20160168)The Analytical&Testing Center of Tiangong University was appreciated.
文摘A high performance preoxidized poly(acrylonitrile)(O-PAN)nanofiber membrane with excellent solvent resistance,thermal stability and flexibility was fabricated by the preoxidation of electrospun PAN nanofiber membrane.The performance of resultant O-PAN nanofiber membrane was optimized by altering the PAN concentration and preoxidation temperature.The results showed that the O-PAN nanofiber membrane which made from PAN concentration of 14%(mass)and preoxidation temperature of 250.0℃ have a more optimal comprehensive performance.In the long-term separation test of SiO2 particle(1 μm)in DMAc suspension,the permeate flux of O-PAN nanofiber membrane stabilized at 227.91 L·m^(-2)·h^(-1)(25℃,0.05 MPa)while the SiO2 rejection above 99.6%,which showed excellent solvent resistance and separation performance.In order to further explore the application of the O-PAN nanofiber membrane,the OPAN nanofiber membrane was treated with fluoride and used in oil/water separation process.The O-PAN nanofiber membrane after hydrophobic treatment showed excellent hydrophobicity and good oil/water separation performance with the permeate flux about 969.59 L·m^(-2)·h^(-1)while the separation efficiency above 96.1%.The O-PAN nanofiber membrane exhibited a potential application prospect in harsh environment separation.