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.

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.

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.

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.

Nanofibers enabled advanced gas sensors:A review

The advancement of gas sensor technology over the past decades has led to remarkable progress and achievements in pollution control and environmental protection.Compared with other sensing materials,electrospun nanofibers have attracted significant attention,which is mainly due to their unique characteristics,including but not limited to high surface area,easy structure design,facile facility setup,multifunctional properties,etc.,making them outstanding candidates for potential applications in this field.This review provides an overview of the applications of electrospun nanofibers in gas sensors,concentrating on carbon monoxide,hydrogen,carbon dioxide,hydrogen sulfide,ammonia,nitrogen oxides,oxygen,and volatile organic compounds.It begins with a brief introduction to sensing materials and the advantages of electrospun nanofibers along with their ongoing research.The principles and progress of electrospinning are then discussed.Afterward,the corresponding properties of electrospun nanofibers in diverse gas sensors are thoroughly reviewed.Finally,a future vision regarding challenges and perspectives in this area is proposed.This review provides an extensive and comprehensive reference to utilize advanced electrospun nanofibers to generate novel sensors,facilitating their performance in high-demand areas.

Flexural destructive process of unidirectional carbon/carbon composites reinforced with in situ grown carbon nanofibers

Unidirectional carbon/carbon（C/C） composites modified with in situ grown carbon nanofibers（CNFs） were prepared by catalysis chemical vapor deposition. The effect of in situ grown CNFs on the flexural properties of the C/C composites was investigated by detailed analyses of destructive process. The results show that there is a sharp increase in the flexural load-displacement curve in the axial direction of the CNF-C/C composites, followed by a serrated yielding phenomenon similar to the plastic materials. The failure mode of the C/C composites modified with in situ grown CNFs is changed from the pull-out of single fiber to the breaking of fiber bundles. The existence of interfacial layer composed by middle-textured pyrocarbon, CNFs and high-textured pyrocarbon can block the crack propagation and change the propagation direction of the main crack, which leads to the higher flexural strength and modulus of C/C composites.

Efficient and Stable Photoassisted Lithium‑Ion Battery Enabled by Photocathode with Synergistically Boosted Carriers Dynamics

Efficient and stable photocathodes with versatility are of significance in photoassisted lithium-ion batteries(PLIBs),while there is always a request on fast carrier transport in electrochemical active photocathodes.Present work proposes a general approach of creating bulk heterojunction to boost the carrier mobility of photocathodes by simply laser assisted embedding of plasmonic nanocrystals.When employed in PLIBs,it was found effective for synchronously enhanced photocharge separation and transport in light charging process.Additionally,experimental photon spectroscopy,finite difference time domain method simulation and theoretical analyses demonstrate that the improved carrier dynamics are driven by the plasmonic-induced hot electron injection from metal to TiO_(2),as well as the enhanced conductivity in TiO2 matrix due to the formation of oxygen vacancies after Schottky contact.Benefiting from these merits,several benchmark values in performance of TiO2-based photocathode applied in PLIBs are set,including the capacity of 276 mAh g^(−1) at 0.2 A g^(−1) under illumination,photoconversion efficiency of 1.276%at 3 A g^(−1),less capacity and Columbic efficiency loss even through 200 cycles.These results exemplify the potential of the bulk heterojunction strategy in developing highly efficient and stable photoassisted energy storage systems.

A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury

Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.

多尺度复合涤纶织物的制备及其水分传递性能

为了改善涤纶的疏水性,拓展涤纶织物的应用场景,采用静电纺纱技术在涤纶芯纱外包覆聚丙烯腈(PAN)亚微米纤维以构建多尺度复合涤纶纱,进而织造成多尺度复合涤纶机织物;同时利用静电纺丝技术在涤纶织物一侧沉积PAN亚微米纤维,并通过热压技术将纤维和织物进行一体化处理,得到多层级多尺度复合涤纶织物。随后对多尺度复合织物的水分传递性能进行深入分析。结果显示,多尺度复合涤纶纱的力学性能主要由芯纱涤纶决定,其芯吸能力和浸润速率均优于传统涤纶纱线,在线密度为28.12 tex时芯吸高度达到51 mm,在59.05 tex时60 s内即可达到浸润平衡状态。此外,机织多尺度复合涤纶织物均可在15 s内实现浸润平衡,而多层级多尺度复合涤纶织物则能在38 s内完成液体的单向传输,展现了良好的反渗透性能。

静电纺纳米纤维在果蔬保鲜中的应用研究进展

新鲜果蔬营养丰富,但是采后易发生失水、衰老、腐烂等品质劣变。包装是果蔬采后重要的商品化处理方式,对于延长果蔬货架期、保持果蔬营养与安全具有重要的作用。静电纺丝技术制备的功能性纳米纤维因相对于传统包装材料的结构和功能优势而受到越来越多的关注。其原理是利用纳米纤维对功能性成分进行包埋或功能修饰,实现抗菌、抗氧化和智能指示或响应等功能的纳米纤维,是食品包装技术的一大进步,其在果蔬采后保鲜方面效果显著。该文综述了静电纺丝制备纳米纤维在不同食品包装领域内的应用,重点总结了纳米纤维在果蔬包装保鲜领域应用的研究进展及发展过程中面临的问题,并对其未来的发展前景进行了展望,以期为果蔬包装保鲜的产业化应用提供理论参考。

静电纺丝聚甲基丙烯酸甲酯基纳米纤维膜的应用

为深入探索聚甲基丙烯酸甲酯(PMMA)基静电纺丝纳米纤维复合材料的应用潜力,文章综述了该材料的制备方法及其在污染物处理、生物医学、能源和光电应用中的研究概况。系统分析了静电纺丝技术在实现纳米级纤维结构中的关键工艺因素,评述了该材料在不同领域的应用效果,阐明了其在光电特性、生物兼容性及可加工性等方面的优势和实际应用潜能,探讨了该材料的未来发展趋势,尤其是在材料功能化改性与多领域集成方面的创新潜力,可为未来相关研究提供理论依据和实践指导。

Preparation of Co_3O_4 Nanofibers via an Electrospinning Technique

Thin PVA/cobalt acetate composite fibers were prepared by using sol-gel processing and electrospinning technique. After calcination of the above precursor fibers, Co3O4 nanofibers with a diameter of 50-150 nm could be successfully obtained. The fibers were characterized by SEM, FT-IR, WAXD, respectively.

Highly Responsive and Selective Ethanol Gas Sensor Based on Co3O4-Modified SnO2 Nanofibers

SnO2 nanofibers were synthesized by electrospinning and modified with Co3O4 via impregnation in this work. Chemical composition and morphology of the nanofibers were system- atically characterized, and their gas sensing properties were investigated. Results showed that Co3O4 modification significantly enhanced the sensing performance of SnO2 nanofibers to ethanol gas. For a sample with 1.2 mol% Co3O4, the response to 100 ppm ethanol was 38.0 at 300 ℃, about 6.7 times larger than that of SnO2 nanofibers. In addition, the response/recovery time was also greatly reduced. A power-law dependence of the sensor response on the ethanol concentration as well as excellent ethanol selectivity was observed for the Co3O4/SnO2 sensor. The enhanced ethanol sensing performance may be attributed to the formation of p-n heterojunctions between the two oxides.

Na_(3.3)La_(0.3)Zr_(1.7)Si_(2)PO_(12)纳米纤维基复合固体电解质研究

利用静电纺丝法制备了一种Na_(3.3)La_(0.3)Zr_(1.7)Si_(2)PO_(12)(NLZSP)纳米纤维,研究了前驱体溶液中聚合物含量和热处理温度对其微观形貌、结构和电化学性能的影响。在前驱体溶液中PVP含量为6%,800℃热处理4 h制备的NLZSP纳米纤维的纯度和结晶度高,纤维尺寸均匀且表面光滑。基于NLZSP纳米纤维制备的PEO(NaClO_(4))复合聚合物电解质(CPE)的室温离子电导率达3.3×10^(−4)S/cm,而PVDF-HFP(NaClO_(4))基CPE的室温离子电导率也达到了3.24×10^(−4)S/cm,活化能仅有0.24 eV,电化学稳定窗口可达5 V以上,显示出优异的电化学性能和稳定性。基于PVDF-HFP-NaClO_(4)-NLZSP纳米纤维的CPE、Na_(4)MnCr(PO_(4))3@C正极的固态钠金属电池在0.1 C时的首次放电比容量可达106.2 mAh/g,经倍率循环后容量保持率为94.8%;其在2 C下循环100次后的容量保持率也高达85.4%,显示出良好的循环稳定性。

纤维素纳米纤维和LATP修饰的PEO固体电解质的制备及其性能研究

采用静电纺丝制备了醋酸纤维素纳米纤维膜,并进行去乙酰化处理和引入Li_(1.4)Al_(0.4)Ti_(1.6)(PO_(4))_(3)无机颗粒对聚氧化乙烯(PEO)电解质进行改性,可提高离子电导率,锂离子迁移数以及锂硫电池的循环稳定性。结果表明:经纤维素纳米纤维和LATP改性的PEO固体电解质在60℃下离子电导率达3.43×10^(-4)S/cm,锂离子迁移数达0.44,高于PEO固体电解质。改性PEO固体电解质在60℃,0.1C下初始放电比容量为844.13mAh/g,且达到了50圈循环。

柔性PAN/TMAB复合纳米纤维膜的压电性能研究

自供电柔性压电纳米发电机因其优异的压电性、良好的柔性和舒适性引起了广泛的关注。通过静电纺丝技术制备了聚丙烯腈(PAN)掺杂三甲基氨硼烷(TMAB)柔性全有机复合纳米纤维膜。系统地研究了纺丝电压和辊筒转速对复合纳米纤维膜压电和铁电性能的影响。结果表明:在纺丝电压为21 kV和辊筒转速为1000 r/min时,PAN/TMAB复合纳米纤维膜的输出性能最佳,输出开路电压和短路电流可达2.60 V和0.59μA。在同样的纺丝条件下,剩余极化强度最大值为0.34μC/cm^(2)。经过6000次敲击循环测试,所制备的PAN/TMAB复合纳米纤维膜输出电压保持稳定。PAN/TMAB复合纳米纤维膜可实时监测手指关节弯曲,行走和跳跃等状态,在可穿戴电子领域有着潜在的应用前景。

多枝金纳米颗粒催化氢化物还原反应的无标记SERS监测

表面增强拉曼散射(SERS)技术,作为一种极具潜力的分子光谱手段,正引领着贵金属纳米粒子在催化化学反应领域的深入研究。其中,金纳米颗粒(AuNP)作为催化剂,在催化氢化物参与的化学反应中展现出卓越的催化性能。通过化学吸附将4-硝基硫酚分子(4-NTP)覆盖于AuNP纳米探针表面,通过在纳米探针表面修饰三种不同分枝的多枝金纳米颗粒(短枝纳米星、长枝纳米星和纳米树莓),用于4-硝基硫酚向4-氨基硫酚(4-NTP)的高效催化转化。利用SERS技术监测反应过程,捕捉金属纳米星与溶液界面处分子结构的变化,研究AuNP界面反应的动力学过程。研究结果表明,AuNP的催化活性与其尖端的尖锐程度和分枝的数量密切相关。研究结果为从分子层面理解并优化催化机制提供了借鉴。

多功能静电纺丝纳米纤维空气滤材研究进展

为了更好促进静电纺丝技术制备多功能高效低阻空气过滤材料,开发制备适用于不同场景的功能型空气过滤纳米纤维膜,推动静电纺丝产业发展,综述了近年来国内外利用静电纺丝技术制备多功能纳米纤维空气滤材的研究进展,对具有抗菌、舒适导湿、保健及抗紫外线等多功能高效低阻空气滤材进行了重点介绍,并回顾其研究进展,分析了现有多功能空气滤材研究中存在的不足,并对其应用前景和发展方向进行了总结与展望。对比传统纤维滤材,利用静电纺丝技术开发的多功能高效低阻空气滤材具有生产高效、应用广泛、易功能改性等优势,在空气过滤领域具有广泛的应用前景。

Electrospun nanofibers as a wound dressing for treating diabetic foot ulcer

Diabetes is one of the most prevalent diseases in the world with high-mortality and complex complications including diabetic foot ulcer(DFU). It has been reported that the difficulties in repairing the wound related to DFU has much relationship with the wound infection,change of inflammatory responses, lack of extracellular matrix(ECM), and the failure of angiogenesis. Following the development of medical materials and pharmaceutical technology, nanofibers has been developed by electrospinning with huge porosity, excellent humidity absorption, a better oxygen exchange rate, and some antibacterial activities. That is to say, as a potential material, nanofibers must be a wonderful candidate for the DFU treatment with so many benefits. Careful selection of polymers from natural resource and synthetic resource can widen the nanofibrous application. Popular methods applied for the nanofibrous fabrication consist of uniaxial electrospinning and coaxial electrospinning. Furthermore, nanofibers loading chemical, biochemical active pharmaceutical ingredient(API)or even stem cells can be wonderful dosage forms for the treatment of DFU. This review summarizes the present techniques applied in the fabrication of nanofibrous dressing(ND)that utilizes a variety of materials and active agents to offer a better health care for the patients suffering from DFU.

Direct fabrication of cerium oxide hollow nanofibers by electrospinning

Electrospinning technique was used to fabricate PVP/Ce（NO3）3 composite microfibers. Different morphological CeO2 nanofibers were obtained by calcination of the PVP/Ce（NO3）3 composite microfibers and were characterized by scanning electron microscopy （SEM）, Transmission electron microscopy （TEM）, X-ray diffraction （XRD）, thermal gravimetric and differential thermal analysis （TG-DTA）, and （FTIR）. SEM micrographs indicated that the surface of the composite fibers was smooth and became coarse with the increase of calcination temperatures. The diameters of CeO2 hollow nanofibers （300 nm at 600 ℃ and 600 nm at 800 ℃ ） were smaller than those of PVP/Ce（NO3）3 composite fibers （1-2 um ）. CeO2 hollow nanofibers were obtained at 600 ℃ and CeO2 hollow and porous nanofibers formed by nanoparti- cles were obtained at 800 ℃. The length of the CeO2 hollow nanofibers was greater than 50 um. XRD analysis revealed that the composite microfibers were amorphous in structure and CeO2 nanofibers were cubic in structure with space group O^5H - FM3m when calcination tem- peratures were 600-800 ℃. TG-DTA and FTIR revealed that the formation of CeO2 nanofibers was largely influenced by the calcination temperatures. Possible formation mechanism of CeO2 hollow nanofibers was proposed.