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Engineering porous organic polymers (POPs) into 1D morphology holds significant promise for diverse applications due to their exceptional processability and increased surface contact for enhanced interactions with guest molecules. This article reviews the latest developments in nanofibrous POPs and their derivatives, encompassing porous organic polymer nanofibers, their composites, and POPs‐derived carbon nanofibers. The review delves into the design and fabrication strategies, elucidates the formation mechanisms, explores their functional attributes, and highlights promising applications. The first section systematically outlines two primary fabrication approaches of nanofibrous POPs, i.e., direct bulk synthesis and electrospinning technology. Both routes are discussed and compared in terms of template utilization and post‐treatments. Next, performance of nanofibrous POPs and their derivatives are reviewed for applications including water treatment, water/oil separation, gas adsorption, energy storage, heterogeneous catalysis, microwave absorption, and biomedical systems. Finally, highlighting existent challenges and offering future prospects of nanofibrous POPs and their derivatives are concluded. [ABSTRACT FROM AUTHOR]

Lightweight and low-cost one-dimensional carbon materials, especially biomass carbon fibers with multiple porous structures, have received wide attention in the field of electromagnetic wave absorption. In this paper, graphene-coated N-doped porous carbon nanofibers (PCNF) with excellent wave absorption properties were successfully synthesized via electrostatic spinning, electrostatic self-assembly, and high-temperature carbonization. The obtained results showed that the minimum reflection loss of the absorbing carbon fiber obtained under the carbonization condition of 800 °C is −51.047 dB, and the absorption bandwidth of reflection loss below −20 dB is 10.16 GHz. This work shows that carbonization temperature and filler content have a certain effect on the wave-absorbing properties of fiber, graphene with nanofiber, and the design and preparation of high-performance absorbing materials by combining the characteristics of graphene and nanofibers and multi-component coupling to provide new ideas for the research of absorbing materials. [ABSTRACT FROM AUTHOR]

Supercapacitors have attracted attention as efficient energy storage systems owing to their high power density and cycling stability. The use of appropriate electrode materials is important for high-performance supercapacitors, and various carbon materials have been studied as supercapacitor electrodes. In this study, carbon nanofibers with high specific surface areas were fabricated via a simple electrospinning process. Carbon nanofibers were fabricated by adjusting the ratio of polyacrylonitrile (PAN) to bisphenol A (BPA) and evaluated as electrode materials for supercapacitors. With the addition of BPA, improved specific surface area and oxygen functional groups were observed compared with nanofibers using only PAN. Therefore, BPA3, which had the highest specific surface area, exhibited a 28% improvement in capacitance (162 F/g) compared with BPA0 fabricated using only PAN. Carbon nanofibers fabricated by adjusting the ratio of BPA to PAN are promising electrodes for supercapacitors owing to their high capacitance and stability. [ABSTRACT FROM AUTHOR]

The electrospinning technique is employed for the synthesized cobalt ferrite/carbon nanofibers, utilizing iso-propanol as the solvent. The nanofibers prepared are subjected to sintering at three different temperatures. A comprehensive analysis is carried out on the structural, morphological, dielectric, impedance, and electromagnetic shielding effectiveness within the X-band frequency range (8.2–12.4 GHz). The application of the Debye-Scherer formula yielded an estimated crystallite size of 22 nm. The electrical response of cobalt ferrite/carbon nanofibers pellet is characterized by employing impedance spectroscopy. Variations in impedance plane plots are discussed based on frequency dependent relaxation time modulations. The impact of sintering temperature is observed in terms of increased impedance values and modifications in the conduction mechanism. These changes are contributed to distinct hopping carriers' linkages between Fe3+-Fe2+ and Co3+-Co2+ ions. Dielectric studies are elucidated considering cation polarizability, colossal resistivity, and tangent loss. This study revealed notable characteristics of CoFe 2 O 4 /C nanofibers, including colossal resistivity (8.45 × 108 Ωcm), a dielectric constant of 22, and colossal tangent loss. The CoFe 2 O 4 /C nanofibers exhibit a characteristic electromagnetic interference (EMI) shielding performance of 30–35 dB. This remarkable shielding performance is observed in nanofibers with a 3 mm thickness, specifically in sample S1 that underwent sintering at a low temperature. The shielding effectiveness is demonstrated within the X-band frequency range. [ABSTRACT FROM AUTHOR]

This contribution describes the preparation, coupled with detailed characterization, of Nb2O5 nanofibers and their application in lithium–sulfur batteries for the improvement of electrochemical performance. The utilization of reactive needle-less electrospinning allowed us to obtain, in a single step, amorphous pre-ceramic composite PAN/Nb2O5 fibers, which were transformed into porous ceramic Nb2O5 nanofibers via calcination. Thermogravimetric studies defined that calcination at 600 °C results in crystalline ceramic fibers without carbon residues. The fibrous morphology and mean diameter (614 ± 100 nm) of the ceramic nanofibers were analyzed via scanning and transmission electron microscopy. A surface area of 7.472 m2/g was determined through nitrogen adsorption measurements, while a combination of X-ray diffraction and Raman spectroscopy was used to show the crystallinity and composition of the fibers after calcination—single T-phase Nb2O5. Its performance in the cathode of lithium–sulfur batteries was defined through electrochemical tests, and the obtained results were compared to a similar blank electrode. The initial discharge capacity of 0.5 C reached a value of 570 mAh∙g−1, while the reversible capacity of 406 mAh∙g−1 was retained after 200 cycles, representing a capacity retention of 71.3%. The presence of Nb2O5 nanofibers in the carbon cathode inhibits the shuttle effect through polysulphide confinement, which originates from porosity and chemical trapping. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel CCMS NCNFs electrode was synthesized via an electrospinning route followed by hydrothermal process. • The multidimensional structure can synergistically shorten ion diffusion path and improve the electronic conductivity. • The formed heterointerface of heterostructured multi-component metal sulfides can accelerate reaction kinetics by synergetic effect. • The obtained CCMS NCNFs electrode shows notable Li+/Na+/K+ storage performance. Transition metal sulfides with the high theoretical capacity and low cost have been considered as advanced anode candidate for alkali metal ion batteries, but suffered from unsatisfactory electrical conductivity and huge volume expansion. Herein, a multidimensional structure Cu-doped Co 1- x S 2 @MoS 2 in-situ-grown on N -doped carbon nanofibers (denoted as Cu-Co 1- x S 2 @MoS 2 NCNFs) have been elaborately constructed for the first time. The bimetallic zeolitic imidazolate framework CuCo-ZIFs were encapsulated in the one-dimensional (1D) NCNFs through an electrospinning route and then on which the two-dimensional (2D) MoS 2 nanosheets were in-situ grown via a hydrothermal process. The architecture of 1D NCNFs can effectively shorten ion diffusion path and enhance electrical conductivity. Besides, the formed heterointerface between MOF-derived binary metal sulfides and MoS 2 can provide extra active centers and accelerate reaction kinetics, which guarantee a superior reversibility. As expected, the resulting Cu-Co 1- x S 2 @MoS 2 NCNFs electrode delivers excellent specific capacity of Na-ion batteries (845.6 mAh/g at 0.1 A/g), Li-ion batteries (1145.7 mAh/g at 0.1 A/g), and K-ion batteries (474.3 mAh/g at 0.1 A/g). Therefore, this innovative design strategy will bring a meaningful prospect for developing high-performance multi-component metal sulfides electrode for alkali metal ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] Electrochemical nitrate (NO 3 −) reduction is a promising approach to relieve nitrate pollution and produce value-added ammonia (NH 3), but efficient and durable catalysts are required due to the large bond dissociation energy of nitrate and low selectivity. Herein, we propose chromium carbide (Cr 3 C 2) nanoparticles loaded carbon nanofibers (Cr 3 C 2 @CNFs) as electrocatalysts to convert nitrate to ammonia. In phosphate buffer saline containing 0.1 mol L−1 NaNO 3 , such catalyst achieves a large NH 3 yield of 25.64 mg h−1 mg−1 cat. and a high faradaic efficiency of 90.08% at −1.1 V vs the reversible hydrogen electrode, which also shows excellent electrochemical durability and structural stability. Theoretical calculations reveal the adsorption energy for nitrate at Cr 3 C 2 surfaces reaches −1.92 eV and the potential determining step (*NO→*N) for Cr 3 C 2 hits a low energy increase of 0.38 eV. [ABSTRACT FROM AUTHOR]

Two-dimensional molybdenum disulfide (MoS2) is considered as a highly promising anode material for lithium-ion batteries (LIBs) due to its unique layer structure, large plane spacing, and high theoretical specific capacity; however, the overlap of MoS2 nanosheets and inherently low electrical conductivity lead to rapid capacity decay, resulting in poor cycling stability and low multiplicative performance. This severely limits its practical application in LIBs. To overcome the above problems, composite fibers with a core//sheath structure have been designed and fabricated. The sheath moiety of MoS2 nanosheets is uniformly anchored by the hydrothermal treatment of the axial of carbon nanofibers derived from an electrospinning method (CNFs//MoS2). The quantity of the MoS2 nanosheets on the CNFs substrates can be tuned by controlling the amount of utilized thiourea precursor. The influence of the MoS2 nanosheets on the electrochemical properties of the composite fibers has been investigated. The synergistic effect between MoS2 and carbon nanofibers can enhance their electrical conductivity and ionic reversibility as an anode for LIBs. The composite fibers deliver a high reversible capacity of 866.5 mA h g−1 after 200 cycles at a current density of 0.5 A g−1 and maintain a capacity of 703.3 mA h g−1 after a long cycle of 500 charge–discharge processes at 1 A g−1. [ABSTRACT FROM AUTHOR]

Bone tissue engineering integrates biomaterials, cells, and bioactive agents to propose sophisticated treatment options over conventional choices. Scaffolds have central roles in this scenario, and precisely designed and fabricated structures with the highest similarity to bone tissue have shown promising outcomes. On the other hand, using nanotechnology and nanomaterials as the enabling options confers fascinating properties to the scaffolds, such as precisely tailoring the physicochemical features and better interactions with cells and surrounding tissues. Among different nanomaterials, polymeric nanofibers and carbon nanofibers have attracted significant attention due to their similarity to bone extracellular matrix (ECM) and high surface-to-volume ratio. Moreover, bone ECM is a biocomposite of collagen fibers and hydroxyapatite crystals; accordingly, researchers have tried to mimic this biocomposite using the mineralization of various polymeric and carbon nanofibers and have shown that the mineralized nanofibers are promising structures to augment the bone healing process in the tissue engineering scenario. In this paper, we reviewed the bone structure, bone defects/fracture healing process, and various structures/cells/growth factors applicable to bone tissue engineering applications. Then, we highlighted the mineralized polymeric and carbon nanofibers and their fabrication methods. [ABSTRACT FROM AUTHOR]

ZnS–graphene composites (ZnSGO) were synthesized by a hydrothermal process and loaded onto carbon nanofibers (CNFs) by electrospinning (ZnS–GO/CNF), to obtain self-standing anodes for SIBs. The characterization techniques (XRPD, SEM, TEM, EDS, TGA, and Raman spectroscopy) confirm that the ZnS nanocrystals (10 nm) with sphalerite structure covered by the graphene sheets were successfully synthesized. In the ZnS–GO/CNF anodes, the active material is homogeneously dispersed in the CNFs' matrix and the ordered carbon source mainly resides in the graphene component. Two self-standing ZnS–GO/CNF anodes (active material amount: 11.3 and 24.9 wt%) were electrochemically tested and compared to a tape-casted ZnS–GO example prepared by conventional methods (active material amount: 70 wt%). The results demonstrate improved specific capacity at high C-rate for the free-standing anodes compared to the tape-casted example (69.93 and 92.59 mAh g−1 at 5 C for 11.3 and 24.9 wt% free-standing anodes, respectively, vs. 50 mAh g−1 for tape-casted). The 24.9 wt% ZnS–GO/CNF anode gives the best cycling performances: we obtained capacities of 255–400 mAh g−1 for 200 cycles and coulombic efficiencies ≥ 99% at 0.5 C, and of 80–90 mAh g−1 for additional 50 cycles at 5 C. The results suggest that self-standing electrodes with improved electrochemical performances at high C-rates can be prepared by a feasible and simple strategy: ex situ synthesis of the active material and addition to the carbon precursor for electrospinning. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethane (TPU) has been widely used as the elastic polymer substrate to be combined with conductive nanomaterials to develop stretchable strain sensors for a variety of applications such as health monitoring, smart robotics, and e-skins. However, little research has been reported on the effects of deposition methods and the form of TPU on their sensing performance. This study intends to design and fabricate a durable, stretchable sensor based on composites of thermoplastic polyurethane and carbon nanofibers (CNFs) by systematically investigating the influences of TPU substrates (i.e., either electrospun nanofibers or solid thin film) and spray coating methods (i.e., either air-spray or electro-spray). It is found that the sensors with electro-sprayed CNFs conductive sensing layers generally show a higher sensitivity, while the influence of the substrate is not significant and there is no clear and consistent trend. The sensor composed of a TPU solid thin film with electro-sprayed CNFs exhibits an optimal performance with a high sensitivity (gauge factor ~28.2) in a strain range of 0–80%, a high stretchability of up to 184%, and excellent durability. The potential application of these sensors in detecting body motions has been demonstrated, including finger and wrist-joint movements, by using a wooden hand. [ABSTRACT FROM AUTHOR]

Sol-gel electrospinning process was used to prepare electrospun carbon nanofibers (ECNFs) from polyacrylonitrile and graphite nanoplatelets. The nanofibers of as-electrospun carbon were calcinated in argon from room temperature to 500 °C for 1h. Scanning and transmission electron microscopy with energy-dispersive X-ray spectroscopy and X-ray diffractometry (XRD) were used to characterize the synthesized ECNFs. The smooth ECNFs with a diameter of 129 ± 43 nm comprised conical platelets of 30–200 µm length. The plane-layered nanofibers contained crystallites along the long fiber axis and were mainly parallel. [ABSTRACT FROM AUTHOR]

The schematic diagram of the synthesis process of the Sb-SnSb/TiO 2 @CNFs-0 and Sb-SnSb/TiO 2 @CNFs-2 composite nanofibers and the corresponding cycling comparison curves of the assembled coin cells. [Display omitted] • The Sb-SnSb/TiO 2 @CNFs composite nanofibers are fabricated through electrospinning. • TiO 2 mitigates the phase separation between SnSb alloy particles and CNFs matrix. • CNFs can accommodate volume changes and increase electronic conductivity. • The Sb-SnSb/TiO 2 @CNFs-2 composite anode exhibits enhanced cycle and rate capacity. The SnSb and TiO 2 nanoparticles uniformly embedded into continuous and conductive carbon nanofibers (CNFs) are successfully fabricated through facile electrospinning combined with calcination treatments. The characterization results of the targeted composite nanofibers (Sb-SnSb/TiO 2 @CNFs-2) confirm that the presence of TiO 2 is of significant importance to construct the elaborately designed and intact fiber structure, in which the optimal dosage of the TiO 2 precursor is precisely controlled at 2 mmol. Moreover, high theoretical specific capacity of SnSb, available inhibitory effect of TiO 2 , and great electronic conductivity of CNFs are cooperatively integrated into the Sb-SnSb/TiO 2 @CNFs-2 composite nanofibers, guaranteeing the enhanced lithium storage capacity and cycling performance when being employed as the anode electrodes. Specifically, the Sb-SnSb/TiO 2 @CNFs-2 electrode can not only deliver initial discharge specific capacity of 1146.6 mAh/g at 100 mA/g and reversible discharge specific capacity of 580.4 mAh/g after 100 cycles, but also retain discharge specific capacity of 561.3 mAh/g after rate cycles along with recovering the current density to 100 mA/g. Importantly, the Sb-SnSb/TiO 2 @CNFs-2 electrode is also endowed with prominent advantages in the pseudocapacitive contribution of 66.89 % at 0.8 mV/s. Those investigations and findings of the Sb-SnSb/TiO 2 @CNFs-2 composite electrodes with facile fabrication process and excellent electrochemical performance can contribute to the practical application of the alloy anodes in the field of the energy storage. [ABSTRACT FROM AUTHOR]

A nanocomposite comprised of nickel titanate/titania nanoparticles decorated with carbon nanofibers (NiTiO3/TiO2-decorated CNFs) is successfully synthesized via electrospinning and further utilized for methylene blue (MB) photodegradation. The morphology, phase, structural and chemical composition of the nanocomposite is investigated via scanning electron microscope, X-ray diffraction and transmission electron microscope equipped with energy dispersive X-ray. A mathematical model is developed to predict the photocatalytic activity of the produced nanocomposite by considering parameters such as initial dye concentration, light intensity, reaction temperature, and catalyst dosage. The reaction rate constant K1 decreased from 0.0153 to 0.0044 min−1 with an increase in the MB concentration from 5 to 15 mg L−1, while K2, K3, and K4 were found to increase with the increase in reaction temperature (0.0153 to 0.0222 min−1), light intensity (0.0153 to 0.0228 min−1) and catalyst dose concentration (0.0153 to 0.0324 min−1), respectively. The results obtained are found to be in good agreement with the modeling results and showed effective photodegradation activity. The performance of our catalyst is found to be better compared to other catalysts previously reported in the literature. The recyclability data of the synthesized NiTiO3/TiO2-decorated CNFs catalyst for four runs show that the catalyst is quite stable and recyclable. This nanocomposite photocatalyst offers a low-cost solution for wastewater pollution problems and opens new avenues to further explore the electrospinning method for the synthesis of nanocomposites. [ABSTRACT FROM AUTHOR]

PPy@B-NCS/CNF composites exhibit excellent electrochemical performance as electrode materials for asymmetric supercapacitors. [Display omitted] • Thedensity functional theory calculation shows that the doping of boron increases the conductivity and oxidation resistance of Ni-Co sulfide, reduces the adsorption energy of hydroxide ions, and thus significantly improves the electrochemical performance. • Electrospinning Carbon Nanofibers (CNF) as the framework and substrate of composites can effectively improve the specific surface area and conductivity of electrode materials, showing excellent electrochemical properties. Surface coating of polypyrrole further improves conductivity and electrochemical stability. • The PPy@B-NCS/CNF delivers high specific capacity, high rate performance and excellent cycle stability. The device has good cycle reversibility and stability after low temperature treatment back to 20 °C. Although nickel–cobalt bimetallic sulfides have been widely studied for supercapacitor electrodes, how to obtain high specific capacity and cycle stability is still an important challenge. Here, an efficient chemical redox method is used to adjust the crystal and electronic structure of cobalt–nickel sulfide (NCS) via B doping, combined with electrospinning technology and conductive polymer polypyrrole (PPy) coating to facilitate faraday redox reactions and obtain high energy density electrode materials. The resulting composite with boron-doped nickel–cobalt sulfide on electrospinned carbon nanofibers with polypyrrole-coating (PPy@B-NCS/CNF) has a high specific capacity (751.61C/g at 1 A/g) and good cycle stability (82.49 % retention after 4000 cycles at 5 A/g). With PPy@B-NCS/CNF as the positive electrode and activated carbon as the negative electrode, an asymmetric supercapacitor (ASC) is prepared. It has excellent electrochemical properties with a power density of 65.58 Wh kg−1 and an energy density of 819.72 W kg−1. The low-temperature performance test shows high reversibility, which provides the possibility for the development of low-temperature electrolytes. Finally, density functional theory (DFT) explains that B-doped NCS has better electrochemical properties from the energy band and state density. [ABSTRACT FROM AUTHOR]

Transition−metal−based materials show great promise for energy conversion and storage due to their excellent chemical properties, low cost, and excellent natural properties. In this paper, through simple strategies such as classical electrospinning, air calcination, and the one−step hydrothermal method, a large area of Ni(OH)2 nanosheets were grown on NiMoO4 nanofibers, forming NiMoO4@Ni(OH)2 nanofibers. The one−dimensional nanostructure was distributed with loose nanosheets, and this beneficial morphology made charge−transfer and diffusion more rapid, so the newly developed material showed good capacitance and conductivity. Under the most suitable experimental conditions, the optimal electrode exhibited the highest specific capacitance (1293 F/g at 1 A/g) and considerable rate capability (56.8% at 10 A/g) under typical test conditions. Most interestingly, the corresponding asymmetrical capacitors exhibited excellent electrochemical cycle stability, maintaining 77% of the original capacitance. NiMoO4@Ni(OH)2 nanofibers were verified to be simple to prepare and to have good performances as energy−storage devices within this experiment. [ABSTRACT FROM AUTHOR]

Nanocarriers are gaining significant importance in the modern era of drug delivery. Nanofiber technology is one of the prime paradigms in nanotechnology for various biomedical and theranostic applications. Nanofibers obtained after successful electrospinning subjected to surface functionalized for drug delivery, biomedical, tissue engineering, biosensing, cell imaging and wound dressing application. Surface functionalization entirely changes physicochemical and biological properties of nanofibers. In physicochemical properties, wettability, melting point, glass transition temperature, and initial decomposition temperature significantly change offer several advantageous for nanofibers. Similarly, biological properties include cell adhesion, biocompatibility, and proliferation, also changes by functionalization of nanofibers. Various natural and synthetic materials polymers, metals, carbon materials, functional groups, proteins, and peptides, are currently used for surface modification of nanofibers. Various research studies across the globe demonstrated the usefulness of surface functionalized nanofibers in tissue engineering, wound healing, skin cancers, melanoma, and disease diagnosis. The delivery of drug through surface functionalized nanofibers results in improved permeation and bioavailability of drug which is important for better targeting of disease and therapeutic efficacy. This review provides a comprehensive insight about various techniques of surface functionalization of nanofibers along with its biomedical applications, toxicity assessment and global patent scenario. [ABSTRACT FROM AUTHOR]

Carbon nanofibers (CNFs) with excellent conductivity and stability have become a promising material to design the strain sensing network. To date, however, the effect of the stacked structure of CNF membrane on the sensing performance has rarely been studied. In this work, we reported a high-performance sensor based on the cross-stacked aligned CNF membrane. The effects of cross-stacked structures on the sensing characteristics were systematically investigated. The flexible strain sensor could capture low detection limit (<0.1%) with a gauge factor (GF) of 4.24 and wide strain range up to 130%. The uniform GF value reached 2050 when the strain was in the range of 100–130%. In addition, the high linearity under 40% strain (>0.998), excellent durability and quick response time (<200 ms) were demonstrated. The excellent comprehensive performances were simultaneously obtained. The sensor could be used in extensive applications, such as monitoring body movements and distinguishing the track of writing. [ABSTRACT FROM AUTHOR]

The efficient use of renewable energy sources requires development of new electrocatalytic materials for electrochemical energy storage systems, particularly fuel cells. To increase durability of high temperature polymer electrolyte fuel cell (HT-PEMFC), Pt/carbon black based catalysts should be replaced by more durable ones, for example Pt/carbon nanofibers (CNF). Here, we report for the first time the quantitative ascorbic acid assisted deposition of Pt onto electrospun polyacrylonitrile-based CNF composite materials. The effect of their subsequent post-treatment at various temperatures (250 and 500 °C) and media (vacuum or argon-hydrogen mixture) on the Pt/C catalyst morphology is investigated. All obtained samples are thoroughly studied by high resolution electron microscopy, and Pt electrochemically active specific surface area was evaluated by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

Herein, we present a novel approach to achieve hierarchical porous nitrogen-doped carbon nanofibers comprising PAN-derived N-doped graphitic carbon and ZIF-8-derived hollow N-doped carbon nanocages and utilized as anodes for potassium-ion batteries. The synergistic effect of N-doped graphitic carbon and hollow N-doped carbon nanocages within the nanostructures resulted in enhanced battery performance. [Display omitted] • Hierarchical porous N-doped carbon nanofibers designed as anodes for potassium-ion batteries. • The nanofibers possess high structural integrity and support rapid electron/ion transfer via numerous conductive pathways. • The nanofibers exhibits high K-ion diffusivity, considerable rate capability, and ultra-long cycle life. Hierarchical porous carbon nanofibers (NFs) are designed via electrospinning, followed by simple carbonization, and applied as the anode for K-ion batteries (KIBs). The carbonization process is optimized to simultaneously satisfy sufficient graphitization of polyacrylonitrile (PAN)-derived soft carbon and complete conversion of zeolitic imidazolate framework-8 (ZIF-8) to hollow N-doped C nanocages. The prepared NFs through an optimized carbonization consists of porous and hollow N-doped C nanocages, which are encapsulated within the conductive graphitic carbon (GC) matrix, that acts as an efficient electron transport pathway. Moreover, the interconnected porous and hollow nanocages ensure a high contact area between the electrode and electrolyte and reduces the K-ion diffusion length. The N-doped GC with high electrical conductivity in the structure demonstrates reinforcing structural integrity as well as providing additional transport pathways for the unique electron transport. Therefore, the hierarchical porous carbon NFs show outstanding energy storage properties, such as stable cycle performance up to 10,000 cycles at the high current density of 1.0 A g-1 with high areal loading mass (1.8–1.9 mg cm−2) of the active material, which clearly suggests the structural advantages of the nanostructure introduced in this study. [ABSTRACT FROM AUTHOR]

The hurdle of fabricating asymmetric supercapacitor (ASC) devices using a faradic cathode and a double layer anode is challenging due to the required large amount of active mass of anodic material compared to that of the cathodic material during mass balancing due to the large difference in capacitance values of the two electrodes. Here, the problem is addressed by engineering a negative electrode that furnishes an ultrahigh capacitance. An in situ developed metal–organic framework (MOF)‐based thermal treatment is adopted to grow highly porous N‐doped carbon nanotubes (CNTs) containing submerged Co nanoparticles over nano‐fibrillated electrospun hollow carbon nanofibers (HCNFs). The optimized CNT@HCNF‐1.5 furnishes an ultrahigh capacitance approaching 712 F g–1 with excellent rate capability. The capacitance reported from this work is the highest for any carbonaceous material reported to date. The CNT@HCNF‐1.5 is further used to fabricate symmetric supercapacitors (SSCs), as well as ASC devices. Remarkably, both the SSC and ASC devices furnish incredible performances in all aspects of SCs, such as a high energy density, long cycle life, and high rate capability, displaying decent practical applicability. The energy density of the SSC device reaches as high as 20.13 W h kg–1, whereas that of ASC approaches 87.5 W h kg–1. [ABSTRACT FROM AUTHOR]

Titanium oxynitride carbon composite nanofibers (TiON/C-CNFs) were synthesised with electrospinning and subsequent heat treatment in ammonia gas. In situ four-probe electrical conductivity measurements of individual TiON/C-CNFs were performed. Additionally, the TiON/C-CNFs were thoroughly analysed with various techniques, such as X-ray and electron diffractions, electron microscopies and spectroscopies, thermogravimetric analysis and chemical analysis to determine the crystal structure, morphology, chemical composition, and N/O at. ratio. It was found that nanofibers were composed of 2–5 nm sized titanium oxynitride (TiON) nanoparticles embedded in an amorphous carbon matrix with a small degree of porosity. The average electrical conductivity of a single TiON/C-CNF was 1.2 kS/m and the bulk electrical conductivity of the TiON/C-CNF fabric was 0.053 kS/m. From the available data, the mesh density of the TiON/C-CNF fabric was estimated to have a characteristic length of 1.0 µm and electrical conductivity of a single TiON/C-CNF was estimated to be from 0.45 kS/m to 19 kS/m. The electrical conductivity of the measured TiON/C-CNFs is better than that of amorphous carbon nanofibers and has ohmic behaviour, which indicates that it can effectively serve as a new type of support material for electrocatalysts, batteries, sensors or supercapacitors. [ABSTRACT FROM AUTHOR]

The (Ni,Fe)S 2 /NiFe(3:1)-CNFs exhibit a highly efficient property for oxygen evolution reaction at a low potential in an alkaline medium. [Display omitted] • Fe-doped NiS 2 crystals on NiFe-carbon nanofibers are successfully prepared. • The electrocatalyst shows abundant exposed active sites and excellent electron/mass transport properties. • The electrocatalyst presents a low overpotential of 287 mV at 30 mA cm−2 for OER. • The overall water splitting device exhibits a cell voltage of 1.54 V to attain 10 mA cm−2. The construction of high-efficiency and low-cost electrocatalysts toward oxygen evolution reaction (OER) to improve the overall water decomposition performance is a fascinating route to deal with the clean energy application. Herein, Fe-doped NiS 2 crystals grown on the surface of carbon nanofibers (CNFs) encapsulated with NiFe alloy nanoparticles ((Ni,Fe)S 2 /NiFe-CNFs) are fabricated through an electrospinning-calcination-vulcanization process, which has been used as a splendid electrocatalyst for OER. Benefitting from the abundant electrochemical active sites from the incorporation of Fe element in NiS 2 and the synergistic effect between NiFe-CNFs and surface sulfides, the obtained (Ni,Fe)S 2 /NiFe-CNFs catalyst exhibits highly electrochemical activities and satisfactory durability toward OER in an alkaline medium with a low overpotential of only 287 mV at a high current density of 30 mA cm−2, and with a little decline in the current retention after 48 h, suggesting its superior OER performance even compared with some noble metal-based electrocatalysts. Additionally, a two-electrode system conducted by using the (Ni,Fe)S 2 /NiFe-CNFs and commercial Pt/C as electrodes, only needs a cell voltage of 1.54 V to afford 10 mA cm−2 for overall water splitting, which is even much better than the RuO 2 ||Pt/C electrolyzer. This study offers a promising approach to prepare high-efficiency OER catalysts toward overall water splitting. [ABSTRACT FROM AUTHOR]

Polycarbosilane nanofiber-ferroferric oxide (PCS nf -Fe 3 O 4) films were assembled on both sides of carbon nanotube-polyaniline buckypaper (CNT-PANI BP) by electrospinning to obtain PCS nf -Fe 3 O 4 /CNT-PANI BP/PCS nf -Fe 3 O 4 sandwich porous composites, with a diameter of 110–120 mm and a thickness of 150–200 µm. The Fe 3 O 4 nanoparticles adhered on the PCS nanofibers formed a bamboo-like or plum-like structure. The PANI nanoparticles were uniformly embedded in the CNT network. Both PCS nf -Fe 3 O 4 film skin layers were well bonded to the CNT-PANI BP core layer, with two main forms of the interlayer interface of rattan-like and root-like entanglement. The sandwich composite film (SCF) with 15.1 wt% Fe 3 O 4 in the skin layers had a density of 0.97 g/cm3, a porosity of 61% and a total pore area of 30.1 m2/g, with a multimodal pore size distribution. The SCFs were superflexible, being tightly wound around a 4 mm diameter glass rod and repeated 100 times without damage. The absorption performance of the SCF was significantly improved by introducing Fe 3 O 4 nanoparticles into its skin layers. The SCF with 11.8 wt% Fe 3 O 4 in its skin layers achieved optimal dielectric and magnetic loss matching, with minimum reflection loss of − 43.54 dB and maximum effective absorption bandwidth of 6.97 GHz. • A superflexible, ultralight, ultrathin and porous SCF absorber was constructed. • The SCFs tightly wound around a 4 mm diameter rod for 100 cycles without damage. • The SCFs had minimum RL of − 43.54 dB and maximum EAB of 6.97 GHz. • Skin and core layers bonded well, with rattan- and root-like entanglement interface. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of NiMnS/carbon fibers (CFs) was made as anodes by regulating Ni/Mn ratio. • NiMnS/CFs delivered the final discharge capacities of 730 mA h g−1 at 0.1 A g−1. • After 250 cycle, NiMnS/CFs exhibited 99% of capacity retention at 1 A g−1. • DFT predicts fast charge–discharge rate with low diffusion energy barrier for Li+. • NiMnS/CFs-based full cell shows a specific energy 529 W h kg−1 and stable durability. Transition metal sulfides (TMSs) have been appraised as promising anode materials for lithium-ion batteries (LIBs), however, the average conductivity and drastic pulverization produced by specific volume variation during discharge–charge cycles limit their practical application. To resolve these critical issues, an in-situ fabrication approach has been utilized to develop binary TMS-embedded carbon nanofibers (CFs) by regulating the loading of metallic (cationic) components. Herein, a series of NiMnS/CFs-n composites was prepared by controlling Ni/Mn feeding ratios (n) via successive electrospinning, carbonization and sulfidation method. The inventive engineering procedure provides excellent durability (∼99 % compared to 2nd cycle) up to 250 cycles at 1 A g−1 and superb rate performance for NiMnS/CFs-2.0 anode. The final discharge capacities of NiMnS/CFs-2.0 are 730, 608, 562, 468, 370, and 306 mA h g−1 at 0.1, 0.3, 0.5, 1, 3, and 5 A g−1, respectively. Theoretical calculations enable us to understand the role of typical Ni/Mn feeding ratio on electronic properties and confirm that the hybrid NiMnS/CFs-2.0 surface provides enhanced material conductivity, improved Li adsorption energies for S-top sites, and fast discharge–charge rate with low diffusion energy barrier. Meanwhile, the full-cell containing NiMnS/CFs-2.0 anode outperforms the commercialized graphite anode with a high specific energy of ∼529 W h kg−1 and stable durability, which also successfully enlightens a light bulb. The present study will provide a scalable and simple method to fabricate the integrated composite of binary TMS/CFs by proper cationic regulation and offer useful guidelines for commercial applications of TMS-based anode. [ABSTRACT FROM AUTHOR]

[Display omitted] Electrospinning is an effective technique to fabricate one-dimensional materials. In this study, cobalt-embedded carbon nanofibers (Co@CNFs) are obtained via carbonization of electrospun cobalt Prussian blue analogue (Co-Co PBA) under nitrogen atmosphere. The Co@CNFs have metallic cobalt surrounded by graphitic carbon shells and possess high specific surface area, rich porosity, high graphitic degree, and rational nitrogen doping. The structure merits endow them with excellent electrocatalytic performances for oxygen reduction reaction (ORR): an onset potential of 0.867 V vs. RHE and 0.784 V vs. RHE at j = − 3 mA cm−2 with a four-electron transfer process. Through a further mild oxidation process, we obtain Co 3 O 4 nanoparticles-embedded nitrogen-doped carbon (Co 3 O 4 @CNFs) with spindle-like morphology. When working as the anode materials for lithium-ion batteries (LIBs), Co 3 O 4 @CNFs show high specific capacity, good stability, and excellent rate capability. The Co 3 O 4 @CNFs anode delivers a discharge specific capacity of 1404 mA h g−1 after 100 cycles at a current density of 100 mA g−1 and about 500 mA h g−1 after 500 cycles at 2000 mA g−1. The diffusion- and capacitive-controlled processes both contribute to the charge storage of the Co 3 O 4 @CNFs electrode. This study provides a new strategy to fabricate the excellent electrocatalysts for ORR and anode materials for LIBs via facile electrospinning. [ABSTRACT FROM AUTHOR]

High-performance electromagnetic (EM) wave absorption property could be achieved by architecture design of nanomaterials. Herein, two layer hybrid Co 0.2 Fe 2.8 O 4 /carbon nanofibers with porous three-dimensional (3D) hierarchical structure were synthesized successfully through facile electrospinning, carbonization and mild chemical treatment. The Co 0.2 Fe 2.8 O 4 particles grew along the carbon nanofibers, forming the enhanced heterogeneous interfaces and high specific areas. As expected, the EM wave absorbent showed an excellent absorbing capability. The composites achieved a maximum reflection loss (RL) of −43.45 dB at 11.1 GHz with thickness of 3.0 mm. More importantly, the effective bandwidth (RL ≤ −10dB) was 5.85 GHz, covering 30% of the entire measured bandwidth. The absorption intensity and bandwidth were superior to other typical CoFe-based composites. The intrinsic mechanism of the absorption revealed that the polarization losses, magnetic losses, magnetic natural resonance and exchanged resonance losses contributed to the high-performance microwave absorption. Moreover, good impedance matching and complex transmission paths that generated from unique porous network also played an important role. This study is expected to guide future exploration on designing and synthesizing high performance EM wave absorbents. [ABSTRACT FROM AUTHOR]

The rich redox chemistry of vanadate-based materials makes them a potential anode for the fabrication of advanced lithium-ion batteries (LiBs). However, poor electrical conductivity as well as volume variation of vanadate-based anode materials hinders practical applications. Herein, magnesium vanadate (MgV 3 O 8) incorporated carbon nanofibers (CNFs) (MgVO@CNFs) composites were prepared via a simple and scalable electrospinning technique, followed by pyrolysis. The synergistic effect of MgVO and CNFs effectively offers a good conductive path and excellent integrity between the active particles with highly porous network. As an anode for LiBs, the MgVO@CNFs composite electrode exhibited good discharge capacity values of 457 mA h g−1 (over 300 cycles) and 245 mA h g−1 (over 500 cycles) at 0.1 and 0.5 A g−1, respectively and revealed excellent rate performance. The charge storage mechanism of MgVO@CNFs is contributed by both capacitive and diffusion-controlled behaviors. Consequently, this novel preparation process of the MgVO@CNFs may provide a new idea for the fabrication of different kinds of nanostructures for LiB applications. [Display omitted] • MgVO@CNFs composite materials are prepared by a facile and scalable electrospinning method. • The MgVO@CNFs composite materials are used as an anode material for lithium-ion batteries. • The MgVO@CNFs composite electrode provide a good conductive path and excellent integrity. • The MgVO@CNFs composite electrode exhibits an excellent specific capacity. • Even at 0.5 A g−1, the MgVO@CNFs composite electrode delivers a capacity of 245 mA h g−1 after 500 cycles. [ABSTRACT FROM AUTHOR]

Lithium-ion supercapacitors (LICs) have received widespread interests because of their high power density, high energy and long life characteristics. The electrodes for LICs play a significant role in enhancing their performance. Therefore, it is of great significance to design and develop high-performance electrode materials for LIC through integrating various materials to make up for each other's disadvantages. Herein, a bimetallic composite nanomaterial with hierarchical structures (CoSn X /CNFM) and a porous carbon nanomaterial with high specific surface area (PCNFM) were obtained through combining electrospinning, anion exchange or alkali etching and subsequent high-temperature carbonization, respectively. The LIC assembled with the pre-lithiated CoSn X /CNFM as anode and the PCNFM as cathode exhibited a high energy density of 41.48 Wh/kg at a power density of 1500 W/kg, and still had an energy density of 28.13 Wh/kg at a high power density of 7500 W/kg, illustrating its high power density and high energy density. Thus, this paper proposes an effective method for designing and manufacturing high-performance LICs. • Nanofibers with uniformly distributed ZIF-67 NPs were prepared in batches by EMAI. • Hierarchical-structured CoSn X /CNFM was prepared by anion exchange and carbonization. • PCNFM with high specific surface area was prepared by etching and carbonization. • A LIC with pre-lithiated CoSn X /CNFM as anode and PCNFM as cathode was assembled. • The assembled LIC had high power density and high energy density. [ABSTRACT FROM AUTHOR]

In this study, carbon nanofibers (CNFs) were successfully manufactured from special polyacrylonitrile (SPAN) copolymer/graphene nanoplates (GNPs) via an electrospinning process after that stabilization and carbonization approaches. The carbonization stage for stabilized SPAN/GNPs nanofibers was applied by heating the samples to 900 °C under an N 2 inert atmosphere. The relationship of the GNPs concentration with morphological and structural properties of SPAN/GNPs composite nanofibers has been examined. The fineness and crystallinity of composite nanofiber increase with increasing concentration of GNPs from 0 to 4 wt%. With increasing the GNPs concentration in the SPAN/GNPs solutions from 0 to 4 wt%, the average diameter of nanofibers decreased from 480 ± 78 nm to 174 ± 18 nm. All CNFs samples synthesized at 900 °C have acceptable morphological, structural, and electrical properties. Moreover, the microstructure of the SCNFs can be controlled with GNPs concentration in composite nanofibers. The electrical conductivity of CNFs attained from neat nanofibers is 0.25 × 10+4 S/m, which is increased to 1.37 × 10+4 S/m with 4 wt% GNPs. Therefore, the unique 2D structure of GNPs is very suitable for the development of low-cost and conductive CNFs with low temperatures of carbonization. [Display omitted] [ABSTRACT FROM AUTHOR]

A flexible gas sensor based on carbon quantum dot decorated TiO 2 nanofibers (CQD/TiO 2) was prepared by hydrothermal and electrostatic spinning methods to detect formaldehyde at room temperature. SEM, TEM, EDS, XRD and XPS were used to analyze the morphology, structure and composition of the composite. The gas sensing test results show that the working temperature of the material is reduced to room temperature by UV excitation, and subsequently, CQD/TiO 2 exhibits a lower detection limit and faster response/recovery time for formaldehyde by carbon material modification. The flexibility test of CQD/TiO 2 shows that the composite material of metal oxide and carbon material has a certain degree of flexibility. The enhanced sensing performance by UV excitation and CQD modification is attributed mainly to the photogenerated electron transfer and the formation of p-n heterojunctions. The modification of TiO 2 with carbon quantum dots provides an experimental reference for the development of room-temperature flexible MOS-based formaldehyde sensors. [Display omitted] [ABSTRACT FROM AUTHOR]

Tin-based composites have been extensively investigated as a potential anode for high performance lithium-ion batteries (LIBs) up until this point. However, because of extreme volume expansion and crystal crushing, the researchers have consistently experienced a loss in capacity during lithiation and alloying. To buffer the volume change and achieve superior rate capability, the hollow cube-shaped Zn 2 SnO 4 /SnO 2 which is wrapped with one-dimensional N-doped carbon nanofibers (CNFs) is prepared. The composites display a delicate bean pod-like heterointerface structure, in which the built-in electric field between Zn 2 SnO 4 and SnO 2 can help to speed up the transportation of Li-ions during lithiation and delithiation processes. Additionally, the abundant Zn 2 SnO 4 /SnO 2 heterointerfaces expose more active sites and make it easier for electrolyte and Li-ion to penetrate. And the N-doped carbon skeleton outside of the Zn 2 SnO 4 /SnO 2 can help to keep the structural integrity and suppress volume expansion during cycling. As expected, the as-prepared samples exhibit excellent rate performance and a very high ultimate discharge capacity of 765.9 mA h g−1 after 500 cycles at current density of 1.0 A g−1. Furthermore, a full-cell with a prelithiated Zn 2 SnO 4 /SnO 2 @CNFs-600 anode and a LiFePO 4 cathode also displays superior rate and cycling performance. This work highlights the significance of chemical heterointerface engineering in the design of high-performance electrodes for LIBs. • Bean pod-like heterointerface Zn 2 SnO 4 /SnO 2 @CNFs obtained by electrostatic spinning and in-situ pyrolysis. • High reversible capacity (754.9 mA h g−1 at 1.0 A g−1 for 500 cycles) and excellent stability. • Nitrogen-doped carbon nanofibers and heterostructures with synergistic effects. • The in-situ generated Zn 2 SnO 4 /SnO 2 heterointerface facilitates electrolyte infiltration and Li+ storage. [ABSTRACT FROM AUTHOR]

High-performance sodium-ion batteries (SIBs) are highly expected in the field of large-scale static energy storage due to the low expenditure and abundant sodium resource. However, the sodium storage performance of anode materials for SIBs has suffered from the foot-dragging reaction kinetics arising from large-size Na+ during intercalation/deintercalation, which imposes more stringent requirements on the morphology and structure of the potential anode electrodes. Herein, we successfully designed and synthesized a three-dimensional (3D) heterojunction as anode material for SIBs, which assembled by interlayer-expanded MoSe 2 nanosheets perpendicularly anchored on the nitrogen-doped branched TiO 2 @C nanofibers (MoSe 2 @NBT@CNFs). Not only does the branched TiO 2 @C nanofibers suppress the severe self-aggregation of MoSe 2 nanosheets but also buffer the volume expansion during the cycling process. Moreover, an expanded interlamellar distance of MoSe 2 nanosheets accelerate sodium ion diffusion, and strong chemical interactions between MoSe 2 nanosheets and carbon nanofibers are conducive to improve the charge-transfer kinetics and reinforce the structural durability. As might be expected, the MoSe 2 @NBT@CNFs anode can deliver excellent cycling performance with high reversibility (315.2 mAh g 1 after 800 cycles at 2 A g 1) and remarkable rate capability (194.2 mAh g 1 at 30 A g 1). The rational design strategy could offer guidance for developing high-performance metal chalcogenide-based electrode materials for SIBs. [Display omitted] • MoSe 2 @NBT@CNFs heterojunction was successfully designed and synthesized. • TiO 2 @C branches as a backbone to suppress the self-aggregation of MoSe 2 nanosheets. • The formed chemical bonds improve the structure integrity and charge-transfer kinetics. • As-synthesized nanocomposite demonstrates excellent sodium storage performance. [ABSTRACT FROM AUTHOR]

Carbon nanofibers (CNFs) have high specific surface area and great electrochemical stability as the anode materials for alkali metal batteries. However, they also have many defects such as low specific capacity and excessive voltage hysteresis, which hinder their wide application. In this work, Cr/S co-doped CNFs (Cr/S@CNFs) are successfully synthesized via electrospinning technique combined with high temperature treatment. As the anode for lithium ion batteries (LIBs), the Cr/S@CNFs electrode exhibits excellent cycle stability (291.7 mAh g−1 at 2 A g−1 after 900 cycles) and high rate performance (221.3 mAh g−1 at 10 A g−1). Moreover, the electrode also obtains the discharge capacity of 266.2 mAh g−1 after 100 cycles at 0.1 A g−1, showing good ion storage capacity for sodium ion batteries (SIBs). Such outstanding electrochemical performances attribute to the co-doping of Cr and S elements, presenting a reliable and efficient approach for the synthesis of high-performance anode materials. • Cr, S co-doped carbon nanofibers were obtained by electrospinning. • Cr, S co-doped induce defects in carbon nanofibers, and the properties of carbon fibers were optimized. • The Cr/S@CNFs electrode showed excellent performances for Li+/Na+ storage. [ABSTRACT FROM AUTHOR]

Transition metal selenides are regarded as one of the most promising anode materials because of their high theoretical specific capacity and large layer spacing. However, the unstable structural behavior and slow reaction kinetics during electrochemical reactions seriously hinder its application. Herein, a novel nanocomposite structure of WSe 2 /CoSe 2 nanocrystals vertically grown on carbon nanofibers (WSe 2 /CoSe 2 /CNFs) was developed as anode material by electrospinning and heat treatment. In which, the self-supporting structures formed by the intersecting carbon nanofibers effectively alleviate severe volume expansion during sodiation/desodiation process, thus ensuring excellent stability. And the highly exposed CoSe 2 /WSe 2 grown on the surface of carbon nanofibers provide abundant reaction interfaces and fast ion diffusion channels. As expected, the WSe 2 /CoSe 2 /CNFs anode shows excellent electrochemical performance, including high capacity (403.5 mAh g−1 at 0.2 A g−1), long-term cycling stability (333.5 mAh g−1 after 1800 cycles at 5 A g−1 with negligible capacity decay per cycle of only 0.0012 %) and remarkable rate performance (a reversible capacity of 312.6 mAh g−1 is achieved even at a high current density of 20 A g−1). Meanwhile, the excellent sodium storage performance of the WSe 2 /CoSe 2 /CNFs composites electrode was deeply investigated by kinetic analysis. [Display omitted] • Developed three-dimensional WSe 2 /CoSe 2 /CNFs nanocomposites with hierarchical heterostructures. • It was prepared by facile electrospinning method and selenization process. • WSe 2 /CoSe 2 /CNFs anode exhibits long cycle stability at high current density and excellent rate performance. • High performance benefits from the unique heterostructures and the synergistic effect of bimetallic selenium. [ABSTRACT FROM AUTHOR]

A synthesis strategy to obtain hierarchically porous N-doped carbon (P–N–C) nanofibers (NFs) comprising VN nanodots and highly densified-entangled N-doped CNTs (N-CNTs) was visualized. The unique redox-active nanostructure was applied as a multifunctional interlayer for highly stable Li–S batteries (LSBs). The P–N–C skeleton obtained via selective removal of amorphous carbon (AC) and polystyrene (PS) not only guarantees efficient electrolyte percolation but also facilitates rapid diffusion of charged species during charge-discharge processes. Moreover, the N-CNTs constituting the fiber matrix increase the overall conductivity of the framework. Besides, highly conductive vanadium nitride (VN) nanodots act as chemisorption sites for efficient lithium polysulfide capturing and prohibit their diffusion towards the anode through efficient catalytic conversion, thus improving the elemental S utilization. The Li–S cells utilizing P–N–C@VN/N-CNT NF as a multifunctional barrier resulted in decent rate capabilities (559 mA h g−1 at 2.0 C) and long-term cycling stabilities at low and high C-rates (432 mA h g−1 after the 400th cycle at 0.1 C and 290 mA h g−1 at the end of 600th cycle at 1.0 C). This is attributed to the combined synergistic effects of the P–N–C framework, N-CNT matrix, and polar VN nanodots. [Display omitted] • Hierarchically porous nitrogen-doped carbon (P–N–C) nanofibers are prepared. • Comprising VN nanodots and densified entangled N-doped CNTs (N-CNTs). • VN nanodots act as chemisorption sites for efficient anchoring of lithium polysulfide. • N-CNTs increase the overall conductivity of the nanostructure framework. • Li–S cell with P–N–C@VN/N-CNT NF-coated separator exhibits stable performance. [ABSTRACT FROM AUTHOR]

Current study introduces composite polyacrylonitrile - multiwall carbon nanotubes nanofibers (PAN-MWCNTs NFs) coated with conducting polymers (polypyrrole (PPy) or poly(3,4-ethylenedioxythiophene) (PEDOT)) by chemical vapor deposition for efficient glucose detection. The potential of nanofibrous assemblies and nano-conducting elements in biosensing was explored as pre-processing of NFs with MWCNTs and post-processing with CPs were both employed. These 'core-shell' conducting NFs were further employed as platforms for glucose oxidase immobilization for enzymatic detection of glucose. The performance of the biosensors was closely correlated with the concentration of immobilized enzyme and with the type of conducting polymer. The biosensors showed high sensitivities of 92.94 and 81.72 µA/mM.cm−2 for (PAN-MWCNTs)/ PEDOT and (PAN-MWCNTs)/ PPy accompanied by low limit of detection values of 2.30 and 2.38 µM, respectively. Good operational stability was observed throughout twenty-five consecutive measurements, over 90% activity was maintained for both sensors. This study represents proof of concept for the methodology, showcasing the advantages of nanomaterial synthesis for bio-applications. The work was compared thoroughly with previously reported biosensors showing some of the best results reported to date in terms of analytical characteristics. • High-performance glucose biosensors without need for redox mediators. • Chemical vapor deposition of PEDOT or PPy onto composite electrospun composite PAN-MWCNTs NFs. • Synergy between MWCNTs and conducting polymers leads to high sensitivity and low limit of detection. • Immobilization of glucose oxidase onto conducting polymer-coated composite NFs. • Correlation between enzyme concentration and analytical performance. [ABSTRACT FROM AUTHOR]

Designing cathode and anode materials that can accommodate capacity and rate performance is a significant challenge in developing lithium-ion capacitors (LICs). Herein, we synthesize a unique N/S dual-doped hierarchical porous carbon (NSC) under the effect of pore distribution modification and heteroatom doping. The nanosheet shape and pore distribution of NSC are highly adjustable, while it demonstrates a reversible capacity that is tens of times more than that of unaltered pristine active carbon. Meanwhile, the prepared glycerol-engineered polyacrylonitrile nanofiber (GPN) form a fast conducting network in the presence of glycerol and carbon nanotubes (CNTs) and exhibit a 300% higher capacity compared to pure polyacrylonitrile nanofibers at 5 A g−1. On this premise, the constructed highly stable LIC (NSC//GPN x @CNTs) can achieve an energy density of 131.48 Wh kg−1 and have an excellent capacity retention rate (93.5%) over 10,000 cycles at a high current density (5 A g−1). This work may lead to new avenues for the preparation of heteroatom-doped porous carbon and redefine the electrode matching of highly stable LICs. [Display omitted] • Highly tunable pore distribution and nanosheet shape of porous carbon. • The cathode nanofibers exhibit high electrical conductivity. • The LIC achieves high energy density and high power density simultaneously. [ABSTRACT FROM AUTHOR]

[Display omitted] • Functionalized nanofibers (N -CNFs) was produced by electrospinning. • N -CNFs was applied for guiding the oriented growth of perovskite for the first time. • N -CNFs provide nucleation sites as templates to induce crystalline orientation. • PCE of the devices with N -CNFs reaches 24.08 % and excellent stability. Perovskite solar cell (PerSC) is currently-one of the most promising third-generation photovoltaic technologies. However, the defects derived from the inhomogeneous growth of perovskite film exacerbate the charge recombination and ion migration in the devices, thus restricting their power conversion efficiency (PCE) and stability. In this work, we introduce nitrogen-doped carbon nanofibers (N -CNFs) via electrospinning technology to guide the preferential orientation of perovskite crystals for the first time. N -CNFs with abundant nitrogen-containing functional groups provide plentiful nucleation sites and fibrous templates, which guide the preferential orientation growth of crystals and diminish the defects density in the perovskite film. The PCE of the champion device achieved a remarkable improvement from 21.40 % to 24.08 % and demonstrated less than 5 % degradation after 600 h of continuous exposure to the ambient environment. This study provides a novel strategy to realize efficient and stable PerSCs by controlling the heterogeneous nucleation and preferentially oriented growth of perovskite crystals with electrospinning N -CNFs. [ABSTRACT FROM AUTHOR]

Nanofibers are widely used in electrochemical energy storage and conversion because of their large specific surface area, high porosity, and excellent mass transfer capability. Electrospinning technology stands out among the methods for nanofibers preparation due to its advantages including high controllability, simple operation, low cost, and wide adjustability. The practical performance of these fibers is largely determined by their structure. Thus, the development of functional nanofibers must start with the regulation of their structure which has been demonstrated as an effective approach to optimize the electrochemical performance of fiber-based electrodes. After a brief introduction of the principles for electrospinning, the dependence of the fibers' structure on the electrospinning parameters is discussed, providing reliable guidance for the controlled modulation of fiber-based architectures. To highlight the advantages of controllability, the structures of the as-spun fibers are regulated at different scales, including the pores within the fibers, the morphology of the fibers, and the assembly manner of the fibers. Then, the use of these fibers for electrochemical energy storage and conversion is discussed with focused attention on the structure-performance relationship. The current challenges facing the electrospinning technology and proposed prospects for this emerging field are summarized to conclude this review. [Display omitted] [ABSTRACT FROM AUTHOR]

The design and development of flexible and free-standing molybdenum (Mo)-based composite nanomaterials have aroused intensive attention in the fields of electrocatalysis, energy storage, and wearable electronics. In this study, novel nanocomposite membranes constructed with Mo-based compound nanocrystals loaded carbon nanofibers (CNFs) were successfully generated by a combination of electrospinning molybdenum acetylacetone-contained polyacrylonitrile (PAN) solution and subsequent annealing process from 580 to 900 ºC. The relationship and mechanisms between the generation of different types of Mo-based nanocrystals and the annealing temperature were systematically explored. It was found that MoO 2 nanocrystals were formed when the annealing temperature was 580 °C. With the temperature increasing, Mo 2 N nanocrystals began to form due to the reaction between the formed MoO 2 and the N atoms in the PAN macromolecules. At higher temperature like 669 °C, Mo 2 C nanocrystals started to form due to the reaction between Mo 2 N and C atoms in the carbonized PAN macromolecules, and single-phase Mo 2 C nanocrystals were produced in CNFs at 900 ºC. Then, a series of flexible CNF-based nanocomposite membranes embedded with various different types of Mo-based compound nanocrystals were generated by effectively controlling the annealing temperature, which were all utilized as anodes for the construction of lithium-ion batteries. Electrochemical measurements showed that the anode materials annealed at 600 oC possessed the highest specific capacity, which were due to the high theoretical specific capacity of MoO 2 and significantly improved conductivity of Mo 2 N. Moreover, all the as-developed electrodes exhibited excellent cycling stability during the charge-discharge process. The present study provides a facile and broadly-applicable routine to tailor the component, structure, and electrochemical properties of Mo-based nanocrystals in CNFs, which finds huge application potential in the fields of various flexible electrochemical devices. • Mo-based compound nanocrystals loaded carbon nanofibrous membranes were created. • The formation mechanisms of different types of Mo-based nanocrystals were explored. • Tailing the annealing temperature could adjust the phase evolution of Mo-based Nanocrystals. • High performance Mo/C nanofibrous membranes were generated for the anode of LIBs. [ABSTRACT FROM AUTHOR]

Manufacturing lightweight, ultralow filler loading, broad bandwidth and highly efficient microwave absorbers is still a challenge. Herein, we have synthesized Co nanoparticles decorated N-self-doped carbon nanofibers (Co@NCNFs) composite by electrospinning followed by a two-step heat treatment and investigated its electromagnetic (EM) and microwave absorption performances under different filler contents (from 2.5 to 7.5 wt%) in paraffin wax matrix. It is found that the Co@NCNFs composite has strong ferromagnetism and moderate graphitization degree as well as abundant polar groups and defects, and Co nanoparticles encapsulated by graphitic carbon layers with sizes around 45–115 nm are uniformly dispersed in the NCNFs. With increasing the filler loading, the EM attenuation ability is gradually strengthened while the impedance matching level is just the opposite. The EM absorbing properties of the composites are more superior within 5.0 wt% Co@NCNFs loading owing to the synergy of improved impedance matching and satisfactory EM dissipation ability. Under an ultralow filler loading of 2.5 wt%, the optimal reflection loss (RL) can reach as strong as −49.3 dB at 17.83 GHz with a thin thickness of 1.61 mm and the maximum effective absorption bandwidth (EAB, RL<−10.0 dB) is as wide as 5.44 GHz (12.56–16.99 GHz) at 1.92 mm. When the filler loading is only 5.0 wt%, a minimum RL value of −52.3 dB is achieved at 6.36 GHz with the thickness of 3.03 mm and the maximum EAB is 4.64 GHz (13.36–18.00 GHz) at 1.42 mm. Compared to other Co/C composite absorbers, the as-prepared Co@NCNFs composite with well-designed constitute and structure demonstrates the better comprehensive absorption performance at a much lower filler loading. Therefore, the present Co@NCNFs may be more promising for practical applications as lightweight and high-performance EM wave absorbers especially in the medium and high frequency range. [Display omitted] • 1D Co@NCNFs were fabricated as lightweight and highly efficient microwave absorber. • The microwave absorption performance is more superior within 5 wt% filler loading. • The minimal reflection loss reaches −49.3 dB at ultralow filler content of 2.5 wt%. • A maximum effective absorption bandwidth of 5.44 GHz can be achieved. • Well-designed constitute and structure are responsible for the excellent property. [ABSTRACT FROM AUTHOR]

Electrospinning is a common method for preparing nanomaterials. Among many electrospinning materials, electrospun carbon nanofibers (CNFs) have become one of the hot research directions for advanced functional materials owing to their good mechanical properties, high surface area, excellent flexibility, physical and chemical stability. Particularly, significant progress has been made in the engineering advancement of electrospinning, electrospun CNFs and their derived reinforced composites to fulfill various applications. This review aims to afford a comprehensive overview of electrospun CNF reinforced composites. Firstly, the different precursors, the correlative properties, and surface modification strategies (e.g. , physical modification and chemical modification) of electrospun CNFs are introduced. Secondly, the preparation methods of reinforced composites based on electrospun CNFs are described in detail. Then, the functional applications of electrospun CNF reinforced composites are discussed. Finally, the challenges and future solutions of electrospun CNF reinforced composites are also prospected. This review is expected to offer a basic but deep understanding of modification strategies to heighten the surface performances of CNFs for the future development of high-performance electrospun CNF reinforced composites in the composite industry, defense, and aerospace applications. [Display omitted] • Electrospun CNF reinforced composites are widly used in engineering materials. • The precursors and modification strategies of electrospun CNFs are detailly reviewed. • Diverse preparation and application of CNF reinforced composites are summarized. • The current challenges of electrospun CNF reinforced composites are discussed. • The future prospects of CNF-based composites in advanced engineering are proposed. [ABSTRACT FROM AUTHOR]

Silicon-based electrodes hold a great potential application in lithium-ion batteries (LIBs) due to the high-energy-density. However, huge volume expansion and poor electric conductivity hinder the commercial application of silicon-based materials. To alleviate these problems, two different hierarchical core-shell composites, silicon/carbon@porous carbon nanofibers (Si/C@PCNF) and silicon@hollow porous carbon nanofiber (Si@HPCNF) are designed and prepared through coaxial electrospinning. The shell layer prevents silicon contacting with electrolyte directly, and the porous carbon nanofibers shorten Li+ diffusion distance and facilitate ion transport. Compared with Si@HPCNF composites, Si/C@PCNF composites achieve a better electrochemical performance owing to the high surface area (68.05 m2/g) and the fact that silicon nanoparticles are connected to each other by porous carbon in the core. The Si/C@PCNF electrodes deliver a large reversible capacity (842.1 mAh∙g−1 after 500 cycles at 0.5 A∙g−1), a good rate capability (1366.6 mAh∙g−1 at 0.5 A∙g−1) and an excellent cycle stability (420.3 mAh∙g−1 at 2.0 A∙g−1 after 1000 cycles), indicating that it can be served as a promising anode for high-performance LIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO 2) has been considered as a promising anode material for alkaline ion batteries (AIBs), yet the low electrical conductivity and sluggish reaction kinetics have restricted its practical applications, while rational structure design can significantly overcome these drawbacks. Herein, we report a one-step fabrication of ultrafine anatase TiO 2 nanoparticles within holely carbon nanofibers (denoted as A-TiO 2 @HCNFs) via a facile electrospinning method and subsequent annealing treatment. The chemical reaction between TEOS (Si(OC 2 H 5) 4) and PVDF ((CH 2 CF 2) n) in the precursor induces the generation of numerous holes (via 4HF + SiO 2 = SiF 4 ↑+ 2 H 2 O) during the carbonization process by annealing in Ar at 800 °C, leading to the formation of holely structure and the suppression of the anatase-to-rutile phase transformation. When employed as anode materials for AIBs, the A-TiO 2 @HCNFs exhibit a high sodium storage capacity of 206.8 mAh g−1 at 1.0 A g−1 after 500 cycles and a superior rate performance of 188.4 mAh g−1 at 5.0 A g−1, and a lithium storage capacity is 354.0/233.9 mAh g−1 at 0.2/1.0 A g−1 after 100/500 cycles with an excellent rate performance of 145.6 mAh g−1 at 5.0 A g−1. The superior electrochemical performance is related to the unique structure with integration of ultrafine anatase TiO 2 nanoparticles and holely carbon nanofibers, which bring many advantages including improved electrical conductivity, sufficient reaction sites and robust structure stability. [Display omitted] • Template-free one-pot hole generation within carbon nanofibers is realized through chemical reaction between TEOS and PVDF. • Ultrafine anatase TiO 2 nanoparticles were produced and uniformly distributed within the holely carbon nanofibers. • The anatase TiO 2 nanoparticles within holely carbon nanofibers demonstrate excellent sodium and lithium storage performances. [ABSTRACT FROM AUTHOR]

Recently, electrospinning technology has high-potential applications in the large-scale manufacturing of one-dimensional (1D) nano-catalytic functional materials. Herein, Ni nanoparticles embedded within highly N-doped carbon nanofibers (Ni@NCNFs) were fabricated using polyacrylamide (PAM) and nickel acetate (NiAc) aqueous solutions as precursors by electrospinning and subsequent carbonization for the first time. The as-prepared Ni@NCNFs were smoothly applied to the hydrogenation of quinoline toward 1,2,3,4-tetrahydroquinoline and manifested excellent catalytic performance with extremely high selectivity (99.0%) at full conversion (99.3%). The influence factors on the physicochemical properties were further studied, including the carbonization temperature, the PAM mass fractions and the mole ratios between PAM and NiAc (PMA/Ni). The present work demonstrated that electrospinning and carbonization could be potential technologies for manufacturing Ni@NCNFs as an outstanding catalyst for quinoline hydrogenation. Furthermore, PAM rich in nitrogen could serve as a new alternative electrospinning precursor for future applications. [Display omitted] • Polyacrylamide was proved as an excellent electrospinning precursor loaded various metal, including Ni, Co and Cu. • Fibrous Ni@NCNFs with high N-doping were fabricated by electrospinning with subsequent carbonization. • Facilely prepared Ni@NCNFs manifested excellent catalytic performance in quinoline hydrogenation. • 99.0% of 1,2,3,4-tetrahydroquinoline selectivity was achieved at 99.3% of quinoline conversion. [ABSTRACT FROM AUTHOR]

The SnCu-SiO 2 @CNFs composite nanofibers are successfully fabricated by electrospinning and subsequent heat treatments, in which the Sn-Cu alloy particles are uniformly confined in carbon nanofibers (CNFs) in the presence of SiO 2. The characterization results show that incorporating SiO 2 into the CNFs matrix can mitigate the problem of the phase separation between Sn-Cu alloy particles and CNFs and increase the fibrous structural integrity of the composite electrodes. Importantly, the SnCu-SiO 2 @CNFs-1.0 composite electrode displays the improved electrochemical performance when the amount of Cu(Ac) 2 is controlled at 1.0 mmol, in which the discharge specific capacity of the electrode not only delivers 501.8 mAh/g after 100 cycles at 100 mA/g, but also retains 467.4 mAh/g after rate cycles when the current density is abruptly recovered to 100 mA/g. Moreover, the SnCu-SiO 2 @CNFs-1.0 electrode can possess an enhanced Li+ diffusion coefficient of approximately 1.58 × 10−16 cm2 s−1 and a high Warburg coefficient of 568.9 Ω cm2 s−0.5 at room temperature. The enhanced electrochemical performance can be partly ascribed to the complete encapsulation of Sn-Cu alloy particles by the CNFs matrix, and partly to the promotion of the over-all electronic conductivity. Furthermore, the flexible and conductive CNFs matrix and the stable Cu 6 Sn 5 phase can conjoinedly accommodate the volume change of the electrodes during charge/discharge processes. Therefore, the facile strategy for encapsulating Sn-Cu alloy particles into CNFs may offer some a prospective instruction for the alloy anodes in the field of energy storage. [Display omitted] • The SnCu-SiO 2 @CNFs nanofibers are successfully fabricated through electrospinning. • SiO 2 mitigates the phase separation between Sn-Cu alloy particles and CNFs matrix. • CNFs can accommodate volume changes and increase electronic conductivity. • The SnCu-SiO 2 @CNFs-1.0 composite anode exhibits enhanced cycle and rate capacity. [ABSTRACT FROM AUTHOR]

One-dimensional PAN-based carbon nanofibers were prepared by electrospinning in combination with a high-temperature carbonization process. The prepared PAN-based nanofibers were characterized by a high aspect ratio. The microwave absorption property was adjusted by controlling the carbonization temperature. The carbonization temperature affected the degree of graphitization, which directly affected the dielectric loss and further improved the microwave absorption properties of PAN-based carbon nanofibers. The PAN-based carbon fibers were optimized in terms of both maximum reflection loss (RL min) and effective absorption bandwidth (EAB) after carbonization at 800 °C. The PAN-based carbon fiber/paraffin composites containing 10 wt% filler exhibited excellent absorption performance with a maximum reflection loss of − 12.75 dB and an effective absorption bandwidth of 4.88 GHz (13.12–18 GHz) at 2.2 mm, which basically covered the Ku-band (12.88–17.88 GHz). When the absorber thickness was 2.4 mm, the reflection loss at 14.4 GHz was − 11.39 dB, and the maximum effective absorption bandwidth was 5.04 GHz (11.92–16.96 GHz). PAN-based carbon nanofibers showed excellent absorption properties due to the dielectric loss in cooperation with good impedance matching. [Display omitted] [ABSTRACT FROM AUTHOR]

Flexible electrochemical energy storage devices play a vital role in the subject of flexible wearable digital equipment. The key is to devise electrodes with wonderful flexibility, high capacity, and preeminent cycle stability. Therefore, we use tetraethyl orthosilicate as the coupling agent to develop Sb 2 Se 3 /Sb uniformly embedded in carbon nanofibers by electrospinning. Silicon oxide act as a form-stabilizing enhancer, the Sb 2 Se 3 /Sb/C nanofibers membrane exhibits superior mechanical flexibility and splendid electrochemical potassium storage performance. In specific, as the free-standing electrode, Sb 2 Se 3 /Sb/C nanofibers membrane can achieve a high reversible discharge capacity of 372 mAh g−1 at 0.05 A g−1 and 228 mAh g−1 at 1 A g−1 and deliver capacity retention of about 100% at 0.1 A g−1 after 300 cycles. All of these phenomena make it hopeful for the application in flexible potassium-ion batteries. [Display omitted] • Flexible and foldable Sb 2 Se 3 /Sb/C nanofibers membrane was prepared. • Ethyl orthosilicate improved the flexibility of the nanofibers membrane. • Free-standing Sb 2 Se 3 /Sb/C nanofibers membrane showed excellent performance. [ABSTRACT FROM AUTHOR]

Carbon nanofibers (CNFs) with high specific surface area and flexible lap structure are highly desirable for numerous applications such as adsorption films, supercapacitors, heat dissipation elements, and composites. In this work, CNFs were prepared using two major categories of pitches, isotropic pitch (IP) and mesophase pitch (MP), as raw materials to compare their molecular structure effects on the morphology and properties of CNFs. The analysis of scanning electron microscopy results found that some fusions among nanofibers easily formed in IP-derived electrospun nanofibers (IP-SNFs) while an independent and smooth nanofiber morphology were observed in MP-derived electrospun nanofibers (MP-SNFs). Besides, composed of high aromatic molecules content and appropriate aliphatic components, MP-SNFs showed a mitigating exothermic reaction and MP-CNFs exhibited higher specific surface area, conductivity and thermal diffusion coefficient. While with too abundant aliphatic components in IP, there was a violent exothermic reaction of IP-SNFs during the stabilization process, endowing the corresponding IP-CNFs with poor performances. Therefore, thermal behavior of SNFs varied with the molecular structure differences of IP and MP, which had a significant influence on the microstructure and properties of their CNFs. [Display omitted] • Fusions were found in IP-CNFs due to the rapid solidification and intense exotherm of IP-SNFs. • The σ and λ of IP-CNFs at 1000 °C (5.83 S cm−1 and 30.34 mm2 s−1) were lower than MP-CNFs' (10.00 S cm−1 and 53.98 mm2 s−1). • Much aliphatic contents in IP led to violent exothermic reactions while MP with more aromatic molecules slowed down them. [ABSTRACT FROM AUTHOR]