One-dimensional Carbon Nanofibers Research Articles

2D/0D/1D Construction of Ti3C2@ZnCo2O4@Carbon Nanofibers for High-Capacity Lithium Storage

Zn and Co oxides possess high theoretical capacity; however, their application in the field of lithium-ion batteries (LIBs) is greatly limited because of poor conductivity and large volume fluctuation. Herein, the multi-protuberant nanofiber structure was formed by combining two-dimensional (2D) Ti3C2 nanosheets and zero-dimensional (0D) ZnCo2O4 nanoparticles on the surface and inside one-dimensional (1D) carbon nanofibers (Ti3C2@ZnCo2O4@carbon nanofibers) for lithium-ion storage. The Ti3C2@ZnCo2O4@carbon nanofiber composite prepared by electrospinning, annealing, and oxidation at low temperature provides abundant active sites and an efficient conductive network to enhance the storage capacity and transfer rate of lithium ions. The Ti3C2@ZnCo2O4@carbon nanofiber anode provides high reversible specific capacity (1112.51 mA h g–1 at 0.2 A g–1), outstanding cycle stability (603.796 mA h g–1 at 0.5 A g–1 after 300 cycles), and excellent rate performance (455.05 mA h g–1 at 3 A g–1 and maintains 920.17 mA h g–1 when current is restored to 0.1 A g–1). The remarkable Li storage originates from the stable multi-protuberant nanofiber structure and fast electrochemical kinetics. The unique structure design of Ti3C2@ZnCo2O4@carbon nanofibers also provides an effective strategy for other electrochemical fields.

Excellent microwave absorption of lightweight PAN-based carbon nanofibers prepared by electrospinning

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 (RLmin) 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.

A self-supported bifunctional air cathode composed of Co3O4/Fe2O3 nanoparticles embedded in nanosheet arrays grafted onto carbon nanofibers for secondary zinc-air batteries

Secondary zinc-air batteries (ZABs) with a free-standing and flexible air electrode integrated with distinguished bifunctional oxygen electrocatalysts are crucial for achieving better performance. Herein, benefitting from the rational design and simple synthesis, a highly controlled design can be achieved for the first showing of the synthesis of Co3O4/Fe2O3NAs@CNFs with a unique hierarchical nanostructure, consisting of randomly distributed zero-dimensional (0D) Co3O4/Fe2O3 nanoparticles embedded in two-dimensional (2D) MOF derived nitrogen-doped mesoporous carbon flake nanoarrays grown on three-dimensional (3D) microporous network with interconnected conductive one-dimensional (1D) carbon nanofibers from carbonized electrospinning polymer nanofiber film (PMNFs). Under the synergy of 3D hierarchical porous nanostructure and abundant accessible active sites, Co3O4/Fe2O3NAs@CNFs is endowed with excellent bifunctional electrocatalytic activities like those of commercial Pt/C and RuO2, respectively. Rechargeable aqueous ZABs based on Co3O4/Fe2O3NAs@CNFs as air electrodes outperform their counterparts based on Pt/C and RuO2 loaded carbon nanofibers (CNFs) as air electrodes, with a maximum power density of 246 mW cm−2 and excellent cycling stability with no increased polarization even after 40 h. And the assembled flexible solid-state ZABs with Co3O4/Fe2O3NAs@CNFs also display superior performance and bendability.

Rational design of freestanding necklace-like ZnSe with double N-doped carbon layer protection for efficient sodium storage

ZnSe, as a promising electrode material for sodium storage, has a high theoretical capacity, low cost, and excellent physicochemical properties. The poor reaction kinetics and huge volume variation of ZnSe hinder its practical applications. Therefore, in this study, ZnSe electrode materials embedded in carbon nanofibers (ZnSe@NC@NCNFs) were synthesized through electrospinning and selenization using a Zn-based metal-organic framework (Zn-MOF) precursor. During the calcination process, the MOF-derived porous N-doped carbon layer wraps the ZnSe nanoparticles, and the one-dimensional (1D) carbon nanofiber forms a second N-doped carbon protective layer. The interwoven nanofibers can be severed as a freestanding electrode for sodium storage without conductive and binder agents. In situ X-ray diffraction (XRD) demonstrates the formation of irreversible NaZn13 during the initial discharge process, which can act as sodiophilic sites and buffering matrices for subsequent Na+ insertion/extraction. The ZnSe@NC@NCNFs exhibit significant electrochemical performance for sodium storage with high reversible capacity and desired rate performance.

Fe2O3/spinel NiFe2O4 heterojunctions in-situ wrapped by one-dimensional porous carbon nanofibers for boosting oxygen evolution/reduction reactions

One-dimensional (1D) nanofiber structure of electrocatalyst has attracted increasing attention in oxygen evolution/reduction reactions (OER/ORR) owing to its unique structural properties. Here, MIL-53(Fe) and Ni(NO3)2·6H2O are incorporated into the electrospun carbon nanofibers (CNFs) to prepare the nickel-iron spinel-based catalysts (Fe2O3/NiFe2O4@CNFs) with 1D and porous structure. The marked Fe2O3/NiFe2O4@CNFs-2 catalyst has a tube diameter of approximately 300 nm, a high surface area of 282.4 m2 g−1 and a hydrophilic surface (contact angle of 16.5°), which obtains a promising bifunctional activity with ΔE = 0.74 V (E1/2 = 0.84 V (ORR) and Ej10 = 1.58 V (OER)) in alkaline media. Fe2O3/NiFe2O4@CNFs-2 has a higher catalytic stability (93.35%) than Pt/C (89.36%) for 30,000 s tests via an efficient 4e− ORR pathway. For OER, Fe2O3/NiFe2O4@CNFs-2 obtains a low overpotential of 350 mV and a high Faraday efficiency of 92.7%. NiFe2O4 (Ni2+ in tetrahedral position) relies on its variable valence states (NiOOH and/or FeOOH) to obtain good catalytic activity and stability for OER, while CNFs wrap/protect the active components (Fe–N and graphic N) in the carbon skeleton to effectively improve the charge transfer (conductivity), activity and stability for ORR. Porous 1D nanofiber structure provides abundant smooth pathways for mass transfer. It indicates that the bimetallic active substances can promote bifunctional activity by synergistically changing the oxide/spinel interface structure.

One-dimensional ZnSe@N-doped carbon nanofibers with simple electrospinning route for superior Na/K-ion storage

One-dimensional carbon nanofibers are widely applied as anode material in the energy storage field due to its unique structure and high conductivity. In this work, one-dimensional ZnSe@N-doped carbon nanofibers (ZnSe@NC NFs) are successfully synthesized by electrospinning and annealed without extra troublesome conditions. ZnSe nanocrystals are enfolded in the N-doped carbon nanofibers, which can act as a protective layer to avoid the volume expansion of active material and promote ion transport during the cycling process. More importantly, the as-synthesized ZnSe@NC NFs are served as the anode material and display the admirable storage properties for Na/K-ion batteries. The one-dimensional ZnSe@NC NFs material shows the high capacity of 237 mAh/g for Na-ion batteries at a current density of 1 A/g for 2000 cycles. Meanwhile, it also delivers a high discharge capacity of 337 mAh/g for K-ion batteries at 0.2 A/g for 300 cycles. Additionally, it is confirmed that the pseudocapacitive contribution of the nano-structure material is up to 54.5% at a scan rate of 0.6 mV/s through the cyclic voltammetry (CV) measurement in K-ion batteries.

Hierarchical porous carbon nanofibers with enhanced capacitive behavior as a flexible self-supporting anode for boosting potassium storage

Carbonaceous materials with various morphologies and structures have been widely investigated as anode for potassium-ion batteries (PIBs), due to their low cost, nontoxicity, and high conductivity. However, there is still sluggish bulk diffusion in most carbon electrodes, which cannot well meet ever-increasing requirements for high power density. Herein, hierarchical porous one-dimensional carbon nanofibers (HPCNF-5) are successfully fabricated, in which one-dimensional (1D) conductivity nanostructure can facilitate electrons transfer. While the in-situ N-doping and suitable micro/mesopores configurations are beneficial for promoting surface-induced capacitive behaviors. Also, the resulting HPCNF-5 has excellent mechanical flexibility, indicating it can be directly used as a self-supporting electrode, thus endowing decreased overall battery weight and promoting reaction reversibility. These prominent structure advantages give HPCNF-5 electrode a fast ions/electrons diffusion capability, thus realizing superior rate property at a high current density of 2 A g−1 (204.6 mAh g−1) and excellent cyclability (with a capacity retention of 88% after 2000 cycles). Therefore, the findings demonstrate the comprehensive merits by combining 1D conductivity nanostructure, N-doping, hierarchical porous, and flexible self-supporting in one material, contributing to offering reference for constructing other advanced carbon materials.

Nitrogen-doped carbon nanofibers derived from phenolic-resin-based analogues for high-performance lithium-ion batteries

The preparation of one-dimensional (1-D) carbon nanofibers (CNFs) for lithium-ion battery (LIB) anode materials plays a crucial role in electrochemical energy storage, but it still remains a great challenge due to the limited synthesis methods. Herein, we use a facile strategy to prepare the nitrogen-doped porous CNFs with high aspect ratio by direct pyrolysis of their phenolic-resin-based precursors in ammonium atmosphere. The polymer precursors are synthesized via a hydrothermal approach and have very high carbon yield over 50% in mass. Benefited from the unique 1-D porous structure, high nitrogen content and good conductivity, the ammonium-treated N-doped porous CNFs demonstrate an outstanding electrochemical lithium storage performance. The as-prepared N-doped porous CNFs demonstrates a high irreversible capacity of 325.2 mA h g−1 at 1000 mA g−1 together with an excellent long cycling performance (485.1 mA h g−1 at 500 mA g−1) after 500 cycles. This work offers a facile preparation strategy of the N-doped porous CNFs for high-efficiency energy storage electrode materials.

One-dimensional N-doped carbon nanofibers produced by pre-oxide treatment for effective lithium storage.

Amorphous carbon materials have been confirmed as attractive anode materials for lithium-ion batteries. Herein, an effective strategy to fabricate amorphous carbon materials at low temperature under air atmosphere is proposed. As demonstrated, one-dimensional nitrogen-doping carbon nanofibers were obtained through simple electrospinning technology, following low-temperature heat treatment. Meanwhile, the nitrogen-doping concentration can be regulated by the heating temperature, which can further introduce different levels of adsorption sites on the surface of carbon and enhance the electronic conductivity. Based on experimental investigation, carbon nanofibers with a high nitrogen doping concentration of 18.1 at% achieved an outstanding cycling durability (194.0 mA h g-1 at 2.0 A g-1 after 2000 cycles).

Coupling core–shell Bi@Void@TiO2 heterostructures into carbon nanofibers for achieving fast potassium storage and long cycling stability

A multi-core–shell heterostructured Bi@Void@TiO2 embedded in one-dimensional carbon nanofibers was developed, and the obtained Bi@Void@TiO2⊂CNF delivers a comprehensive K-ion storage ability.

Design of Ti4+-doped Li3V2(PO4)3/C fibers for lithium energy storage

In this work, we propose a facile approach to fabricate Ti4+-doped Li3V2(PO4)3/C (abbreviated as C-LVTP) nanofibers using an electrospinning route followed by a high temperature treatment. In this designed nanocomposite, the ultrafine LVTP dots are homogeneously dispersed into one-dimensional carbon nanofibers and the Ti4+ doping does not destroy the crystal structure of monoclinic Li3V2(PO4)3. Compared to the undoped Li3V2(PO4)3/C (abbreviated as C-LVP), the as-fabricated C-LVTP fibers present higher reversible capacity, superior high-rate capability as well as better cyclic property. Especially, the C-LVT7%P cathode delivers not only high capacities of 187.2 and 160.3 mAh g−1 at 0.5 and 10 C respectively, but also stable cyclic property with the reversible capacity of 135.8 mAh g−1 at 20 C following 500-cycle spans. The good battery characteristics of C-LVT7%P can be mainly ascribed to Ti4+ doping, which can increase the electrical conductivity and Li+ diffusion coefficient.

Facile fabrication of Fe/Fe3C embedded in N-doped carbon nanofiber for efficient degradation of tetracycline via peroxymonosulfate activation: Role of superoxide radical and singlet oxygen

The toxic metal ions leaching and metal nanoparticles agglomeration were the critical issues for metal-based carbon materials during the peroxymonosulfate (PMS) activation processes. Herein, a facile strategy was first proposed that zero-dimensional Fe/Fe3C nanoparticles were embedded in one-dimensional N-doped carbon nanofiber (Fe/Fe3C@NCNF) to solve the above challenges. The as-obtained Fe/Fe3C@NCNF-800 possessed a low Ea value (11.7 kJ/mol) and exhibited high activity for activating PMS to degrade tetracycline (TC) in a wide range of pH 3–11. As expected, the iron ions leaching concentration of Fe/Fe3C@NCNF-800 was very low (0.082 mg/L). Meanwhile, the Fe/Fe3C@NCNF-800 was easily recovered from the reaction solution due to its magnetic properties. Both superoxide radicals (O2∙−) and non-radical of singlet oxygen (1O2) were the primary reactive oxygen species (ROS) in the Fe/Fe3C@NCNF-800/PMS system via quenching tests and electron spin resonance spectroscopy (ESR). The catalytic mechanism suggested that the Fe/Fe3C and graphitic N were the main active sites in the Fe/Fe3C@NCNF-800 for PMS activation. This work provided a facile method for the preparation of Fe-based carbon materials with high catalytic ability, low metal leaching and easy recycling, showing a broad prospect for environmental applications.

Constructing one-dimensional mesoporous carbon nanofibers loaded with NaTi2(PO4)3 nanodots as novel anodes for sodium energy storage

In this research, the novel one-dimensional mesoporous NaTi2(PO4)3@C fibers (abbreviated as C-NTP-1D) are synthesized via an electrospinning method to promote the rate capability of pristine NaTi2(PO4)3 (NTP). The electrochemical properties, crystal structure and morphology for the resulted fibers have been explored by various electrochemical testing techniques, XRD, XPS, Raman spectroscopy, SEM as well as TEM. Benefiting from the designed mesoporous structure, the C-NTP-1D anode displays superior electrochemical properties. The specific capacities of 130.1 and 117.7 mAh g−1 is achieved at 0.1 and 2 C, and the C-NTP-1D presents the high capability of 89.1 mAh g−1 at 10 C following 500-cycle spans. Therefore, the designed mesoporous C-NTP-1D nanofibers can find potential applications as novel electrode for sodium-ion batteries.

Scalable Synthesis of High Entropy Alloy Nanoparticles by Microwave Heating

High entropy alloy nanoparticles (HEA-NPs) are reported to have superior performance in catalysis, energy storage, and conversion due to the broad range of elements that can be incorporated in these materials, enabling tunable activity, excellent thermal and chemical stability, and a synergistic catalytic effect. However, scaling the manufacturing of HEA-NPs with uniform particle size and homogeneous elemental distribution efficiently is still a challenge due to the required critical synthetic conditions where high temperature is typically involved. In this work, we demonstrate an efficient and scalable microwave heating method using carbon-based materials as substrates to fabricate HEA-NPs with uniform particle size. Due to the abundant functional group defects that can absorb microwave efficiently, reduced graphene oxide is employed as a model substrate to produce an average temperature reaching as high as ∼1850 K within seconds. As a proof-of-concept, we utilize this rapid, high-temperature heating process to synthesize PtPdFeCoNi HEA-NPs, which exhibit an average particle size of ∼12 nm and uniform elemental mixing resulting from decomposition nearly at the same time and liquid metal solidification without diffusion. Various carbon-based materials can also be employed as substrates, including one-dimensional carbon nanofibers and three-dimensional carbonized wood, which can achieve temperatures of >1400 K. This facile and efficient microwave heating method is also compatible with the roll-to-roll process, providing a feasible route for scalable HEA-NPs manufacturing.

Electrospun IrP2-carbon nanofibers for hydrogen evolution reaction in alkaline medium

Platinum-group metals are the most promising catalysts choice for hydrogen evolution reaction (HER) due to their good catalytic stability and optimum Gibbs free energy for hydrogen adsorption and desorption. However, high cost restricts their industrial application. To lower price, the most commonly used method is to reduce noble metals’ dosage. Herein, iridium (Ir) and its diphosphide (IrP2) based on one-dimensional carbon nanofibers (CNFs) are easily fabricated by electrospinning and following calcination, and then are applied as efficient catalysts for HER. Both Ir-CNFs and IrP2-CNFs show excellent HER performances with overpotentials of 22 mV and 19 mV under the current density of 10 mA cm−2 in alkaline medium, respectively. The experimental results are further proved by density function theory (DFT) calculations, in which IrP2 (2 0 0) shows better HER kinetics than Ir (1 1 1) with lower water adsorption and hydrogen evolution energies. This work presents a simple method to prepare Ir-CNFs and IrP2-CNFs and provides a new feasibility for design and synthesis of efficient and stable HER catalysts.

Gelatin-Derived 1D Carbon Nanofiber Architecture with Simultaneous Decoration of Single Fe-Nx Sites and Fe/Fe3 C Nanoparticles for Efficient Oxygen Reduction.

Exploring high-performance non-precious-metal electrocatalysts for the oxygen reduction reaction (ORR) is critical. Herein, a scalable and cost-effective strategy is reported for the construction of one-dimensional carbon nanofiber architectures with simultaneous decoration of single Fe-Nx sites and highly dispersed Fe/Fe3 C nanoparticles for efficient ORR, through the FeIII -complex-assisted electrospinning of gelatin nanofibers with subsequent pre-oxidation and carbonization. Results show that the presence of a FeIII complex enables the 1D gelatin nanofibers to be well retained during the pre-oxidation process. Owing to the distinct 1D nanofiber structure and the synergistic effect of Fe/Fe3 C and Fe-Nx sites, the resulting electrocatalyst is highly active for ORR with a half-wave potential of 0.885 V (outperforming commercial Pt/C) and a superior electrochemical stability in alkaline electrolytes. Similarly, it also shows a high power density (144.7 mW cm-2 ) and a superior stability in Zn-air batteries. This work opens a path for the design and synthesis of 1D carbon electrocatalyst for efficient ORR catalysis.

Electrospun FeCo nanoparticles encapsulated in N-doped carbon nanofibers as self-supporting flexible anodes for lithium-ion batteries

This work reports a flexible, self-supporting anode, as a novel electrode material to improve the energy density of lithium-ion batteries (LIBs). In this work, FeCo nanoparticles uniformly encapsulated in one-dimensional N-doped carbon nanofibers (denoted as FeCo@NCNFs) were synthesized by electrospinning and subsequent thermal treatment. The as-prepared FeCo@NCNFs films with high electrical conductivity and good flexibility can be directly used as LIBs anodes without the addition of any conductive agents and binders. The lithium storage performance of FeCo@NCNFs is far superior to that of pure NCNFs. The impact of the carbonization temperature on the structure and electrochemical properties of FeCo@NCNFs was also investigated. Results show that FeCo@NCNFs obtained at 600 °C exhibits the optimal electrochemical performance with a relatively high reversible capacity, i.e., 566.5 mA h g−1 at 100 mA h g−1 after 100 cycles. The enhanced electrochemical properties can be mainly attributed to the synergy between 3D conductive NCNFs network and small FeCo nanoparticles, which can effectively improve the utilization rate of active materials, facilitate the transport of the electrons and lithium ions, and promote the charge-transport kinetics. Moreover, the homogeneous dispersion of FeCo nanoparticles in the NCNFs can also greatly buffer the volume change and improve the structural stability of the electrodes during the charge-discharge cycling.

Facile preparation of hierarchical CuO nanostructures as a integrate binder-free anode for high-performance lithium-ion batteries

Novel CuO hybrid nanostructures composed of one-dimensional (ID) porous carbon nanofibers and two-dimensional (2D) graphene nanosheets have been fabricated with the help of electrospinning technique, which is denoted as CuO@PCNF/GN. The microstructure and morphology of the CuO@PCNF/GN were investigated by X-ray diffraction and transmission electron microscopy. The electrochemical performances of the as-prepared materials as a novel bind-free anode for lithium ion battery (LIB) were investigated. The CuO@PCNF/GN electrode exhibited high discharge capacity of 665 mAh g−1 after 60 cycles at the current density of 100 mA g−1. Even at 800 mA g−1, the discharge capacity of the anode could still maintained at 443 mAh g−1. The excellent electrochemical properties of CuO are greatly related to the unique 3D interconnected structure of continuous PCNF and GN, which enables efficient electron/ion transport and migrate the volume change of active CuO materials.

MOF-derived porous carbon nanofibers wrapping Sn nanoparticles as flexible anodes for lithium/sodium ion batteries

Facile synthesis of flexible electrodes with high reversible capacity plays a key role in meeting the ever-increasing demand for flexible batteries. Herein, we incorporated Sn-based metal-organic framework (Sn-MOF) templates into crosslinked one-dimensional carbon nanofibers (CNFs) using an electrospinning strategy and obtained a hierarchical porous film (Sn@C@CNF) after a carbothermal reduction reaction. Merits of this modification strategy and its mechanism in improving the electrochemical performance of Sn nanoparticles (NPs) were revealed. Electrospun CNFs substrate ensured a highly conductive skeleton and excellent mechanical toughness, making Sn@C@CNF a self-supported binder-free electrode. Serving as a self-sacrificing template, Sn-MOF provided Sn NPs and derived into porous structures on CNFs after pyrolysis. The hierarchical porous structure of the carbon substrate was beneficial to enhancing the Li+/Na+ storage of the active materials, and the carbon wrappings derived from polyacrylonitrile (PAN) nanofibers and the MOF skeleton could jointly accommodate the violent volume variation during cycling, enabling Sn@C@CNF to have excellent cycle stability. The Sn@C@CNF anode exhibited a stable discharge specific capacity of 610.8 mAh g−1 under 200 mA g−1 for 180 cycles in lithium ion batteries (LIBs) and 360.5 mAh g−1 under 100 mA g−1 after 100 cycles in sodium ion batteries (SIBs). As a flexible electrode, Sn@C@CNF demonstrated a stable electromechanical response to repeated ‘bending-releasing’ cycles and excellent electrochemical performance when assembled in a soft-pack half-LIB. This strategy provided promising candidates of active materials and fabrication methods for advanced flexible batteries.

Effect of 1D carbon nano- tube and fiber reinforcement on the long-term creep performance of glass fiber/epoxy composite using the time-temperature superposition principle

In this article, one-dimensional (1D) carbon nanotube (CNT) and carbon nanofiber (CNF) is added to glass fiber/epoxy (GE) composite in an attempt to improve its life-long creep resistance. Accelerated deformation of GE and both nanofiller reinforced GE (CNT-GE and CNF-GE) composite were done in 30–120 °C temperature span, and the long-term creep behavior was evaluated by implementing time–temperature superposition principle at 30 °C and 90 °C reference temperature (RT). CNT-GE and CNF-GE composite showed positive creep compliance till ∼109.5 and ∼104.5 years, respectively, at RT of 30 °C as compared to GE composite. However, at a RT of 90 °C, positive creep compliance duration was reduced to ∼800 for CNT-GE and ∼8 days for CNF-GE composite. The creep resistance of both nanofiller reinforced GE composites was highly temperature-sensitive due to an increase in heterogeneity in the composite with second phase nano reinforcement addition. Higher specific surface area and strength of CNTs than CNFs produced better creep resistance in GE composite at lower temperatures.