Bifunctional TiO_(2-x)nanofibers enhanced gel polymer electrolyte for high performance lithium metal batteries

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.

Hard Superconducting Gap in Pb Te Nanowires

Semiconductor nanowires coupled to a superconductor provide a powerful testbed for quantum device physics such as Majorana zero modes and gate-tunable hybrid qubits.The performance of these quantum devices heavily relies on the quality of the induced superconducting gap.A hard gap.

Determination of Thermal Properties of Unsmooth Si Nanowires

We estimate the thermal properties of unsmooth Si nanowires,considering key factors such as size(diameter),surface texture(roughness)and quantum size effects(phonon states)at different temperatures.For nanowires with a diameter of less than 20 nm,we highlight the importance of quantum size effects in heat capacity calculations,using dispersion relations derived from the modified frequency equation for the elasticity of a rod.The thermal conductivities of nanowires with diameters of 37,56,and 115nm are predicted using the Fuchs–Sondheimer model and Soffer’s specular parameter.Notably,the roughness parameters are chosen to reflect the technological characteristics of the real surfaces.Our findings reveal that surface texture plays a significant role in thermal conductivity,particularly in the realm of ballistic heat transfer within nanowires.This study provides practical recommendations for developing new thermal management materials.

Diameter-dependent ultra-high thermoelectric performance of ZnO nanowires

Zinc oxide(ZnO)shows great potential in electronics,but its large intrinsic thermal conductivity limits its thermoelectric applications.In this work,we explore the significant carrier transport capacity and diameter-dependent thermoelectric characteristics of wurtzite-ZnO(0001)nanowires based on first-principles and molecular dynamics simulations.Under the synergistic effect of band degeneracy and weak phonon-electron scattering,P-type(ZnO)_(73) nanowires achieve an ultrahigh power factor above 1500μW·cm^(-1)·K^(-2)over a wide temperature range.The lattice thermal conductivity and carrier transport properties of ZnO nanowires exhibit a strong diameter size dependence.When the ZnO nanowire diameter exceeds 12.72A,the carrier transport properties increase significantly,while the thermal conductivity shows a slight increase with the diameter size,resulting in a ZT value of up to 6.4 at 700 K for P-type(ZnO)_(73).For the first time,the size effect is also illustrated by introducing two geometrical configurations of the ZnO nanowires.This work theoretically depicts the size optimization strategy for the thermoelectric conversion of ZnO nanowires.

Flexible polydimethylsiloxane pressure sensor with micro-pyramid structures and embedded silver nanowires:A novel application in urinary flow measurement

Flexible pressure sensors are lightweight and highly sensitive,making them suitable for use in small portable devices to achieve precise measurements of tiny forces.This article introduces a low-cost and easy-fabrication strategy for piezoresistive flexible pressure sensors.By embedding silver nanowires into a polydimethylsiloxane layer with micro-pyramids on its surface,a flexible pressure sensor is created that can detect low pressure (17.3 Pa) with fast response (<20 ms) and high sensitivity (69.6 mA kPa-1).Furthermore,the pressure sensor exhibits a sensitive and stable response to a small amount of water flowing on its surface.On this basis,the flexible pressure sensor is innovatively combined with a micro-rotor to fabricate a novel urinary flow-rate meter (uroflowmeter),and results from a simulated human urination experiment show that the uroflowmeter accurately captured all the essential shape characteristics that were present in the pump-simulated urination curves.Looking ahead,this research provides a new reference for using flexible pressure sensors in urinary flow-rate monitoring.

Facile Semiconductor p-n Homojunction Nanowires with Strategic p-Type Doping Engineering Combined with Surface Reconstruction for Biosensing Applications

Photosensors with versatile functionalities have emerged as a cornerstone for breakthroughs in the future optoelectronic systems across a wide range of applications.In particular,emerging photoelectrochemical(PEC)-type devices have recently attracted extensive interest in liquid-based biosensing applications due to their natural electrolyte-assisted operating characteristics.Herein,a PEC-type photosensor was carefully designed and constructed by employing gallium nitride(GaN)p-n homojunction semiconductor nanowires on silicon,with the p-GaN segment strategically doped and then decorated with cobalt-nickel oxide(CoNiO_(x)).Essentially,the p-n homojunction configuration with facile p-doping engineering improves carrier separation efficiency and facilitates carrier transfer to the nanowire surface,while CoNiO_(x)decoration further boosts PEC reaction activity and carrier dynamics at the nanowire/electrolyte interface.Consequently,the constructed photosensor achieves a high responsivity of 247.8 mA W^(-1)while simultaneously exhibiting excellent operating stability.Strikingly,based on the remarkable stability and high responsivity of the device,a glucose sensing system was established with a demonstration of glucose level determination in real human serum.This work offers a feasible and universal approach in the pursuit of high-performance bio-related sensing applications via a rational design of PEC devices in the form of nanostructured architecture with strategic doping engineering.

Fabricating AC/DC nanogenerators based on single ZnO nanowires by using a nanomanipulator in a scanning electron microscope

Single zinc oxide nanowires(ZnO NWs)are promising for nanogenerators because of their excellent semiconducting and piezoelectric properties,but characterizing the latter efficiently is challenging.As reported here,an electrical breakdown strategy was used to construct single ZnO NWs with a specific length.With the high operability of a nanomanipulator in a scanning electron microscope,ZnO-NW-based twoprobe and three-probe structures were constructed for fabricating AC/DC nanogenerators,respectively.For a ZnO NW,an AC output of between−15.31 mV and 5.82 mV was achieved,while for a DC nanogenerator,an output of24.3 mV was realized.Also,the three-probe structure’s output method was changed to verify the distribution of piezoelectric charges when a single ZnO NW is bent by a probe,and DC outputs of different amplitudes were achieved.This study provides a low-cost,highly convenient,and operational method for studying the AC/DC output characteristics of single NWs,which is beneficial for the further development of nanogenerators.

Integrated adsorption and photocatalytic removal of methylene blue dye from aqueous solution by hierarchical Nb_(2)O_(5)@PAN/PVDF/ANO composite nanofibers

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.

Optical Properties of GaAs/AlGaAs Nanowires Grown on Pre-etched Si Substrates

GaAs-based nanomaterials are essential for near-infrared nano-photoelectronic devices due to their exceptional optoelectronic properties.However,as the dimensions of GaAs materials decrease,the development of GaAs nanowires(NWs)is hindered by type-Ⅱquantum well structures arising from the mixture of zinc blende(ZB)and wurtzite(WZ)phases and surface defects due to the large surface-to-volume ratio.Achieving GaAs-based NWs with high emission efficiency has become a key research focus.In this study,pre-etched silicon substrates were combined with GaAs/AlGaAs core-shell heterostructure to achieve GaAs-based NWs with good perpendicularity,excellent crystal structures,and high emission efficiency by leveraging the shadowing effect and surface passivation.The primary evidence for this includes the prominent free-exciton emission in the variable-temperature spectra and the low thermal activation energy indicated by the variable-power spectra.The findings of this study suggest that the growth method described herein can be employed to enhance the crystal structure and optical properties of otherⅢ-Ⅴlow-dimensional materials,potentially paving the way for future NW devices.

Constructing orthogonally structured graphene nanointerface on SiC nanowires reinforced carbon/carbon composites to boost mechanical strength and strength retention rate

Carbon/carbon composites with higher mechanical strength and better reliability at elevated tempera-tures are urgently needed to satisfy the practical applications requirements.SiC nanowires(SiCNWs)modified C/C(SC-CC)composites have attracted an abundance of attention for their excellent mechanical performance.To further boost the mechanical strengths of composites and maximize the reinforcing efficiency of SiCNWs,we introduce orthogonally structured graphene nanosheets(OGNs)into SC-CC composites,in which OGNs are grafted on the SiCNWs via chemical vapor deposition(CVD)method,forming SC-G-CC composites.Benefiting from the nano-interface effects,uniform stress distribution,strong SiCNWs/PyC interfacial bonding and elevated stress propagation efficiency in the PyC matrix are achieved,thus SC-G-CC composites accomplish brilliant mechanical properties before and after 1,600℃ heat treatment.As temperature rises to 2,100℃,SiCNWs lose efficacy,whereas OGNs with excellent thermal stability continue to play the nano-interface role in the PyC matrix.Therefore,SC-G-CC com-posites show better mechanical performance after 2,100℃ heat treatment,and the mechanical strength retention rate(MSR)of interlaminar shear strength,out-of-plane and in-plane compressive strength of SC-G-CC composites reach 61.0%,55.7%and 55.3%,respectively.This work proposes an alternative thought for maximizing the potentiality of nanomaterials and edifies the mechanical modification of composites.

Novel Perovskite Oxide Hybrid Nanofibers Embedded with Nanocatalysts for Highly Efficient and Durable Electrodes in Direct CO_(2) Electrolysis

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.

Embedded high-quality ternary GaAs_(1−x)Sb_(x) quantum dots in GaAs nanowires by molecular-beam epitaxy

Semiconductor quantum dots are promising candidates for preparing high-performance single photon sources.A basic requirement for this application is realizing the controlled growth of high-quality semiconductor quantum dots.Here,we report the growth of embedded GaAs_(1−x)Sb_(x) quantum dots in GaAs nanowires by molecular-beam epitaxy.It is found that the size of the GaAs_(1−x)Sb_(x) quantum dot can be well-defined by the GaAs nanowire.Energy dispersive spectroscopy analyses show that the antimony content x can be up to 0.36 by tuning the growth temperature.All GaAs_(1−x)Sb_(x) quantum dots exhibit a pure zinc-blende phase.In addition,we have developed a new technology to grow GaAs passivation layers on the sidewalls of the GaAs_(1−x)Sb_(x) quantum dots.Different from the traditional growth process of the passivation layer,GaAs passivation layers can be grown simultaneously with the growth of the embedded GaAs_(1−x)Sb_(x) quantum dots.The spontaneous GaAs passivation layer shows a pure zinc-blende phase due to the strict epitaxial relationship between the quantum dot and the passivation layer.The successful fabrication of embedded high-quality GaAs_(1−x)Sb_(x) quantum dots lays the foundation for the realization of GaAs_(1−x)Sb_(x)-based single photon sources.

Mesoporous Carbon Nanofibers Loaded with Ordered PtFe Alloy Nanoparticles for Electrocatalytic Nitrate Reduction to Ammonia

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.

Assembly of CdS Nanowires from Solution Using Oriented Nanofibers

This paper presents an universal assembly approach,based on the oriented nanofibers,for the formation of large-scale ordered nanowire arrays.First,CdS NWs solution is dripped onto the substrate surface.Second,before the CdS NWs solution evaporates,the oriented nanofibers slides along the substrate surface to assemble the CdS nanowires.The mechanism involving ordered alignment of nanowires on the substrate surface was investigated based on our experimental results.The resulting nanowires arrays can be further used for the creation of massive nanoelectronic-device arrays.

Nanofiber/nanowires-based flexible and stretchable sensors

Nanofibers/nanowires with one-dimension(1D)nanostructure or well-patterned microstructure have shown distinctly advantages in flexible and stretchable sensor fields,owing to their remarkable tolerance against mechanical bending or stretching,outstanding electronic/optoelectronic properties,good transparency,and excellent geometry.Herein,latest summaries in the unique structure and properties of nanofiber/nanowire function materials and their applications for flexible and stretchable sensor are highlighted.Several types of high-performance nanofiber/nanowire-based flexible pressure and stretchable sensors are also reviewed.Finally,a conclusion and prospect for 1D nanofiber/nanowires-based flexible and stretchable sensors are also intensively discussed.This summary offers new insights for the development of flexible and stretchable sensor based 1D nanostructure in next-generation flexible electronics.

Multicomponent Nanoparticles Synergistic One-Dimensional Nanofibers as Heterostructure Absorbers for Tunable and Efficient Microwave Absorption

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.

Pea-like MoS_(2)@NiS_(1.03)-carbon heterostructured hollow nanofibers for high-performance sodium storage

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.

Integration of Desulfurization and Lithium-Sulfur Batteries Enabled by Amino-Functionalized Porous Carbon Nanofibers

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.

Ni_(3)Fe/Ni_(4)S_(3)/Ni/C Mixed Crystal Composite Nanofibers Prepared by Electrospinning and Heat Treatment Methods for Oxygen Evolution Reaction

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).

ZnO nanowires based degradable high-performance photodetectors for eco-friendly green electronics

Disposable devices designed for single and/or multiple reliable measurements over a short duration have attracted considerable interest recently. However, these devices often use non-recyclable and non-biodegradable materials and wasteful fabrication methods. Herein, we present ZnO nanowires(NWs) based degradable high-performance UV photodetectors(PDs) on flexible chitosan substrate. Systematic investigations reveal the presented device exhibits excellent photo response, including high responsivity(55 A/W), superior specific detectivity(4×10^(14) jones), and the highest gain(8.5×10~(10)) among the reported state of the art biodegradable PDs. Further, the presented PDs display excellent mechanical flexibility under wide range of bending conditions and thermal stability in the measured temperature range(5–50 ℃).The biodegradability studies performed on the device, in both deionized(DI) water(pH≈6) and PBS solution(pH=7.4),show fast degradability in DI water(20 mins) as compared to PBS(48 h). These results show the potential the presented approach holds for green and cost-effective fabrication of wearable, and disposable sensing systems with reduced adverse environmental impact.