Carbon Nanofibers Research Articles

Boronate affinity molecularly imprinted electrochemical sensor based on electrospun carbon nanofibres for selective kanamycin detection

The presence of trace kanamycin (KANA) residues in animal-derived foods from its improper use present a critical public health issue, making the urgent need for the development of sensitive and selective KANA detection methods. In this study, we developed molecularly imprinted polymers (MIPs)-based electrochemical sensor for the detection of KANA, incorporating Co, Mo-doped carbon nanofibres (Co, Mo@CNFs) to modify a glassy carbon electrode (GCE). Then, the MIPs layer was synthesized via electropolymerization using KANA as a template molecule and 3-aminophenylboronic acid (3-APBA) as the functional monomer (as MIPs/Co, Mo@CNFs/GCE), facilitating selective recognition through boric acid affinity. The presence of Co, Mo@CNFs enhanced electron transport across the otherwise insulating MIPs layer, thereby improving the sensor’s selective recognition capabilities. Under optimal conditions, the MIPs/Co, Mo@CNFs/GCE sensor demonstrated precise KANA detection within a concentration range of 1 × 10−2 to 1 × 105 nmol·L−1, achieving a detection limit of 2.56 pmol·L−1. Furthermore, the sensor’s applicability was validated in complex matrices, successfully detecting KANA in serum and milk samples with recovery rates ranging from 95.05 % to 116.43 %. These results confirmed that the proposed sensor is highly effective for detecting KANA in both biological and animal-origin food samples.

Electromagnetic interference shielding properties of foamed SiCnws/SiC composites reinforced by in-situ grown carbon nanofibers

Interwoven network structures composed of one-dimensional nanomaterials with excellent dielectric properties present promising potential for application in the field of electromagnetic interference (EMI) shielding. In this work, the disordered carbon nanofibers (CNFs) are in-situ grown on the interconnected silicon carbide nanowires (SiCnws) aerogel by chemical vapor infiltration (CVI), which is foamed by unidirectional freeze casting. Subsequently, the SiC interface is deposited to construct an engagement of CNFs and SiCnws. Arising from the penetrating structure, the average total EMI shielding efficiency (SET) of the SiCnws/CNFs/SiC composites increases from 28.9 dB to 42.8 dB in X band with just 2 mm thickness. Moreover, the maximum SET value of the composites can be up to 57.2 dB, indicating more than 99.999 % of microwaves will be shielded. The excellent EMI shielding performance can be attributed to integrating multiple loss mechanisms such as conductivity loss, interface polarization loss, and dipole polarization loss. The integrated lightweight composites provide a new design routine for electromagnetic shielding structure components.

Multifunctional hybrid composites from novel asphaltene-based carbon nanofiber mats and woven carbon fiber

Multifunctional hybrid composites from novel asphaltene-based carbon nanofiber mats and woven carbon fiber

Sulfate salt assistant fabrication of Fe-doped Ni2P modified with SO42−/carbon as highly efficient oxygen evolution reaction electrocatalyst

The incorporation of oxyanion groups offers a greater potential for enhancing the activity of oxygen evolution reaction (OER) electrocatalysts compared to traditional metal cations doping, owing to their unique configurations and high electronegativity. However, the incorporation of oxyanion groups that differ from those derived from the oxidation of anions in transition metal monoxides poses significant challenges, thereby limiting further applications of oxyanion group modification approach. Herein, we present a novel sulfate salt assistant approach to fabricate Fe-doped Ni2P modified with SO42−/carbon (Fe-Ni2P-S/C) nanofibers as highly efficient OER electrocatalyst. The optimized Fe-Ni2P-S/C nanofibers display superb OER activity, requiring low overpotentials of 266, 323, and 357 mV at 100, 500, and 1000 mA cm−2, respectively. Theoretical calculations reveal that the co-adsorption of PO43− and SO42− on the surface of reconstructed electrocatalyst can reduce the energy barrier of rate-determining step, thereby resulting in enhanced OER activity. The present study emphasizes the crucial role played by anion groups in OER activity as well as proposes a novel approach for incorporating anion groups into electrocatalysts.

Hierarchical design of carbon nanofibers wrapped antimony selenide nanorods with heteroatom-doped carbon quantum dots as efficient anode material of high-performance sodium-ion batteries

Researchers have focused on sodium-ion batteries (SIBs) due to low precursor costs and abundant reserves. However, low efficiency of anode materials hinders SIB commercialization, mainly due to large ionic radius and slow kinetics of Na+. Metal selenides such as Sb2Se3 have regarded as promising anode materials of SIBs due to high theoretical capacities. Despite this, the practical application has been limited by the poor rate capability, conductivity, and stability. In this study, one-dimensional Sb2Se3 nanorods and nitrogen-doped carbon quantum dots (N-CQDs) combined with carbon nanofibers (CNFs) have been developed as an effective anode material of SIBs. The uniform distribution of N-CQDs in the Sb2Se3 coated CNFs (Sb2Se3/CNFs) anode results in the highest reversible capacity of 647.9 mAhg−1 at 0.05 Ag-1. Moreover, the Sb2Se3 and N-CQDs coated CNFs (Sb2Se3@N-CQDs/CNFs) anode presents a good rate performance and retains a high reversible capacity of 444.7 mAhg−1 at a high current density of 0.4 Ag-1. Additionally, the Sb2Se3@N-CQDs/CNFs anode demonstrates excellent stability, retaining 78.8% of the initial capacity after 100 cycles. The improved electrochemical performance is attributed to low volume expansion and good conductivity due to carbon coating and addition of N-CQDs. Galvanostatic intermittent titration technique is also used to examine Na+ diffusion coefficients.

Electrostatic Interactions Dominate the Surface Assembly of Silicon‐Based Nanospheres on Carbon Nanofibers for Flexible Lithium‐Ion Batteries

AbstractThe construction of flexible freestanding silicon‐based electrodes eliminates the addition of inactive materials, improving the overall energy density, and effectively avoiding the disadvantage of active materials being easily separated from the collector due to the volume effect. However, many reports of flexible freestanding electrodes lack long‐term cycling stability. Here, 3 different silicon‐based freestanding electrodes are designed and find that the freestanding electrode with surface assembly dominated by electrostatic interactions can significantly improve long‐term cycling stability. Owing to better mechanical properties, this surface‐assembled electrode demonstrates unique flexibility. The conductive framework and unique void structure not only reveal the excellent lithium‐ion diffusion capability and charge‐transfer kinetics but also provide ample space for the volume expansion of the silicon‐based material, which endows electrodes with excellent electrochemical performance. With 2 folds, the capacity remains at 471 mA h g−1 after 1000 cycles (0.5 A g−1). In addition, the as‐prepared flexible pouch cell maintains high capacity and cycling stability after folding, with an average capacity degradation of only 0.01% per cycle during 1000 cycles, highlighting its considerable potential in the development of flexible devices. Remarkably, such interfacial assembly on the fiber surface also enables the modulation of multilayer assembly.

MoC nanoparticles decorated carbon nanofibers loaded with Li2S as high-performance lithium sulfur battery cathodes

Lithium sulfur (Li-S) batteries have broad development potential in the field of electrochemical energy storage due to their high theoretical specific capacity, low cost, and environmentally friendly. However, the notorious shuttle effect of lithium polysulfides (LiPSs) during cycling process severely limits the performance improvement of Li-S batteries. In this work, carbon nanofibers (CNFs) decorated by MoC nanoparticles have been successfully established through electrospin combined with carbothermal reduction method. The effect of calcination temperature and MoC loading amount on the catalytic activity on LiPSs, as well as the electrochemical performance have been first investigated in detail. Based on the visualized adsorption and LiPSs conversion kinetics testing, the CNFs@MoC composites with 37 wt% MoC loading (CNFs@MoC-37 %) are confirmed to be the optimized sample. By using liquid-phase impregnation to load Li2S onto the CNFs@MoC-37 % composites to act as cathode, the assembled cells can achieve a reversible capacity of 941 mAh g−1 and 751 mAh g−1 at the current density of 0.1C and 1C respectively. The reversible capacity can still maintain at 550 mAh g−1 at 1C after 500 cycles, corresponding to the capacity decay rate of 0.054 % per cycle.

Polymorph interface strategy presents avenues for kinetics-enhanced and dendrite-free lithium sulfur batteries

Shuttle effect and slow kinetic property are the challenges for the practical application of lithium-sulfur (Li-S) batteries. As an effective strategy, the polymorph effect is applied to rationally design multifunctional catalysts. Herein, the unique polymorph interface was constructed by different CoSe2 crystalline phases, and the systematic investigation on the sulfur cathodes and lithium anode is reported. Carbon nanofiber (CNF) derived from bacterial cellulose (BC) is used as a scaffold for disperse CoSe2 catalysts to construct electrically conductive highways. According to the experimental and calculation results, orthorhombic CoSe2 exhibits superior adsorption capacity and catalytic activity towards LiPSs, while cubic CoSe2 shows better electronic conductivity. Mixed phase CoSe2 not only balances the advantages of both, but also showcases impressive performance due to its unique polymorph interface structure. Besides, uniform lithium deposition can be also achieved. Consequently, the modified separators endow Li-S batteries with a high reversible discharge capacity (700 cycles at 1 C with only 0.063 % capacity decay per cycle) and excellent rate performance (702 mAh g−1 is maintained at 5 C). The pouch cell with separator modifications on both sides was assembled and exhibits a high discharge capacity. This work provides a polymorph interface strategy for the rational design of catalysts.

Enhancement on the thermal and tribological behaviors of polyurethane/epoxy-based interpenetrating network composites by orientationally aligned CNF/MXene/WPU aerogels

Tribological behaviour of polyurethane/epoxy interpenetrating polymer network (PU/EP IPN) as friction materials was investigated. This was a combination of the good flexibility of PU and high hardness of EP to realize polymer synergistic effect of interpenetrating network structure, aiming to broaden and develop the application of polymer-based composites in friction engineering materials. A novel CNF/MXene/WPU aerogel (CMW) was prepared by employing flexible NCO-terminated waterborne polyurethane prepolymer (WPU) as the supporting skeleton of aerogel, and synchronously combining the reinforcing-phase carbon nanofibers (CNF) and lubricating-phase MXene. Subsequently, the prepared ultralight porous yet mechanically robust CMW aerogels were encapsulated with IPN by vacuum impregnation. As expected, the addition of aerogel imparted IPN matrix with enhanced thermal and tribological properties due to the thermal dispersion and enhancement effects conferred on the matrix by the highly aligned and ordered three-dimensional interconnected structure of aerogel. Meanwhile, CMW reinforced IPN composites were explored for the formation of a high-quality transfer film on the contact surface during friction. The transfer film prevented direct contact between the friction couples, which facilitated the improvement of wear resistance of composites, thus giving this material great potential for tribological applications.

3D printed Ti3C2@Polymer based artificial forest for autonomous water harvesting system

The escalating scarcity of freshwater resources presents significant challenges to global sustainability, demanding innovative solutions by integrating cutting-edge materials and technologies. Here we introduce an autonomous artificial forest (3D AF) for continuous freshwater acquisition. This system features a three-dimensional (3D) architecture incorporating a carbon nanofiber (CNF) network and MXene@polypyrrole (Ti3C2@PPy), enhancing surface area, light absorption, heat distribution, and surface wettability to improve solar vapor generation and fog collection efficiency. The autonomous operation is facilitated by an integrated photothermal actuator that adjusts to the day and night conditions. During daylight, the 3D AF tilts downward to maximize solar exposure for water evaporation, while at night, it self-adjusts to optimize fog particle collection. Notably, our device demonstrates the ability to harvest over 5.5 L m−2 of freshwater daily outdoors. This study showcases the potential of integrating advanced materials and technologies to address pressing global freshwater challenges, paving the way for future innovations in water harvesting.

Optimization of the TiO2 content and location in core–shell tubular carbon nanofibers to improve the photocatalytic activity under visible light irradiation

Optimization of the TiO2 content and location in core–shell tubular carbon nanofibers to improve the photocatalytic activity under visible light irradiation

Studies on cytocompatibility of human dermal fibroblasts on carbon nanofiber nanoparticle-containing bioprinted constructs

Functional nanocomposite-based printable inks impart strength, mechanical stability, and bioactivity to the printed matrix due to the presence of nanomaterials or nanostructures. Carbonaceous nanomaterials are known to improve the electrical conductivity, osteoconductivity, mechanical, and thermal properties of printed materials. In the current work, we have incorporated carbon nanofiber nanoparticles (CNF NPs) into methacrylated gelatin (GelMA) to investigate whether the resulting nanocomposite printable ink constructs (GelMA-CNF NPs) promote cell proliferation. Two kinds of printable constructs, cell-laden bioink and biomaterial ink, were prepared by incorporating various concentrations of CNF NPs (50, 100, and 150 µg/mL). The CNF NPs improved the mechanical strength and dielectric properties of the printed constructs. The in vitro cell line studies using normal human dermal fibroblasts (nHDF) demonstrated that CNF NPs are involved in cell-material interaction without affecting cellular morphology. Though the presence of NPs did not affect cellular viability on the initial days of treatment, it caused cytotoxicity to the cells on days 4 and 7 of the treatment. A significant level of cytotoxicity was observed in the highly CNF-concentrated bioink scaffolds (100 and 150 µg/mL). The unfavorable outcomes of the current work necessitate further study of employing functionalized CNF NPs to achieve enhanced cell proliferation in GelMA-CNF NPs-based bioprinted constructs and advance the application of skin tissue regeneration.Graphical abstract

High-loading NaCrO2 @C nanofibers as binder-free cathode for high-stable sodium-ion batteries

A NaCrO2 @C flexible free-standing cathode is designed and fabricated via a facile electrospinning strategy, in which electrochemically active NaCrO2 nanoparticles homogeneously dispersed in the flexible carbon nanofibers. Serving as the binder-free cathode for sodium-ion batteries, the as-constructed NaCrO2@C flexible free-standing cathode delivers a long cycling life (81 % capacity retention after 1000 cycles) with a high loading (7.6 mg cm−2). The enhancements for sodium-ion insertion/desertion is assigned to the dramatically decrease the polarization between electrodes and avoid the volume expansion during high-rate cycling. The NaCrO2@C flexible free-standing cathode opens up exciting possibilities for the development of advanced flexible sodium-ion batteries with both excellent mechanical flexibility and electrochemical properties.

Flexible electrospun carbon nanofibers - Nickel disulfide@carbon nanofibers - Carbon nanofibers sandwich structure as binder-free anode for high performance lithium-ion batteries

People have recently shown increasing interest in wearable and flexible electronics. Due to their high electrical conductivity and flexibility, carbon nanofibers can be utilized for various flexible applications. However, pure carbon nanofibers have low capacity, which makes it challenging to achieve high capacity for flexible applications. Herein, sandwich-like nanofibers - nickel disulfide@carbon nanofibers - carbon nanofibers are obtained through a multi-step electrospinning process to serve as a flexible binder-free anode for lithium-ion batteries. This strategy stabilizes the structure well with two layers of carbon nanofibers, effectively accelerating the Li+diffusion and promoting the electrolyte infiltration. Accordingly, the electrode exhibits a discharge capacity of 551.8 mAh g-1 at 0.1 A g-1 after 100 cycles and achieves a discharge capacity of 523.8 mAh g-1 at 1 A g-1 after 1000 cycles, demonstrating excellent cyclic stability and high capacity for Li+ storage. The kinetic analysis also reveals that the sandwich structure provides a higher capacity contribution. This work introduces a novel approach for creating flexible binder-free anodes with high performance, effectively expanding the application of sulfides through electrospinning.

Mechanical properties and cross-scale synergistic modification mechanism of micro-nano carbon fiber modified concrete

In order to explore the cross-scale synergistic modification effect of carbon fiber (CF) and carbon nanofiber (CNF) on the mechanical properties of concrete, based on CNF modified concrete (NCFC, with CNF volume content of 0.3 %), four kinds of micro-nano carbon fiber modified concrete (MNCFMC, with CNF volume content of 0.3 % and CF volume content of 0.1∼0.4 %) are prepared. For comparison, four kinds of CF modified concrete (CFMC, with CF volume content of 0.1∼0.4 %) are also prepared. The compressive, flexural and splitting tensile strength of concrete are tested, and the cross-scale synergistic modification mechanism is analyzed by SEM and MIP tests. The results show that CF and CNF have cross-scale synergistic improvement effect on the mechanical properties of concrete. The mechanical properties of concrete can be further improved by adding CF with appropriate content on the basis of the addition of CNF. With the increase of CF content, the compressive, flexural and splitting tensile strength of MNCFMC first increase and then decrease. The mechanical properties of MNCFMC are the best when the CF content is 0.2 %, the compressive, flexural and splitting tensile strength of MNCFMC increase by 14.12 %, 19.69 % and 30.32 %, respectively. Compared with CFMC, the mechanical properties of MNCFMC with the same CF content are better. The physical bond between CF and concrete matrix is poor, CNF can enhance the physical bond between CF and concrete matrix by attracting the deposition of cement hydration product crystals. When CF and CNF are added together, the pore size refinement and pore structure optimization effects of fiber on concrete are the best. When the CF content is 0.2 %, the average pore size and total pore volume of MNCFMC decrease by 30.66 % and 16.86 % compared with CFMC, respectively.

Free‐Standing Si@C/CNFs Prepared by Simple Electrospinning as a Stable Anode for Lithium‐Ion Batteries

AbstractThe development of free‐standing and foldable electrodes with excellent electrochemical performance is paramount for flexible electronic devices. However, the silicon‐based free‐standing anodes lack a straightforward preparation process. Herein, we successfully designed a hierarchical Si@C/CNFs composite material by combining hydrothermal and electrospinning techniques, in which the carbon‐coated silicon (Si@C) is served as the primary nanostructure and carbon nanofibers (CNFs) from electrospinning are maintained as the network matrix, resulting in a free‐standing anode. Owing to the amorphous carbon coating on Si nanoparticles and the formation of a 3D network structure of CNFs, which tightly encases the primary Si@C nanostructure, the Si@C/CNFs electrode demonstrates exceptional conductivity and flexibility. This dual carbon‐layer structure further enhances kinetics and mitigates the volume expansion of Si nanoparticles. The Si@C/CNFs electrode exhibits a high specific capacity (1573 mAh g−1 at 0.1 A g−1), exceptional rate capability, and excellent cycling stability (78.5 % capacity retention after 100 cycles). Thus, Si@C/CNFs can be a promising material for the anode electrode in flexible lithium‐ion batteries.

Boron/phosphorus co-doped nitrogen-rich carbon nanofiber with flexible anode for robust sodium-ion battery

Flexible energy storage devices have been paid much attention and adapts to apply in various fields. Benefiting from the active sites of boron (B) and phosphorus (P) doping materials, co-doped carbon materials are widely used in energy storage devices for the enhanced electrochemical performance. Herein, B and P co-doped flexible carbon nanofibers with nitrogen-rich (B-P/NC) are investigated with electrospinning for sodium-ion battery. The flexible of binderless B-P/NC with annealing of 600 °C (B-P/NC-600) exhibits the remarkable performance for the robust capacity of 200 mAh/g at 0.1 A/g after 500 cycles and a durable reversible capacity of 160 mAh/g even at 1 A/g after 12,000 cycles, exhibiting the equally commendable stability of flexible B-P/NC-600. In addition, B-P/NC-600 delivers the reversible capacity of 265 mAh/g with the test temperature of 60 °C. More importantly, the flexible B-P/NC-600 is fabricated as anode for the whole battery, delivering the capacity of 90 mAh/g at 1 A/g after 200 cycles. Meanwhile, theoretical calculation further verified that boron and phosphorus co-doping can improve the adsorption capacity of nitrogen carbon materials. The favorable performance of flexible B-P/NC-600 can be ascribed to the nitrogen-rich carbon nanofibers with three-dimensional network matrix for the more active site of boron and phosphorus co-doping. Our work paves the way for the improvement of flexible anodes and wide-operating temperature of sodium-ion batteries by doping approach of much heteroatom.

Fabrication of novel metal oxide nanosheets-decorated carbon nanofibers for highly efficient removal of ultra-small nanoplastics

The extensive use of plastic products leads to white pollution and the formation of nanoplastics (NPs) through physicochemical processes. Due to their large specific surface area and small size, NPs can easily enter the human body, posing significant health risks. In this work, we prepared NiFe2O4 nanosheets-decorated carbon nanofibers (NiFe2O4@CNF) via electrospinning, carbonization, hydrothermal growth, and low-temperature calcination for NPs removal. Characterization techniques, including SEM, FTIR, XRD, XPS, and zeta potential analysis, assessed the surface morphology, functional groups, crystal structure, chemical composition, and surface charge of the NiFe2O4@CNF adsorbent. Adsorption kinetics, isotherms, and thermodynamics studies demonstrated that the adsorption process follows pseudo-second-order kinetics and the Langmuir model, indicating chemisorption and monolayer adsorption with a maximum adsorption capacity of 147.842 mg/g. Thermodynamic data confirmed that the reaction is spontaneous and endothermic. Additionally, the practical application of the adsorbent was evaluated by studying the effects of pH, competing ions, and different water bodies on adsorption behavior, all showing high removal efficiency and robust performance. Computer simulations further provided understanding into the driving forces and the binding sites of adsorption. These results underscore the efficacy of NiFe2O4@CNF for NPs removal and provide critical insights for designing advanced environmental remediation materials.

Cooperative Control of Bioelectrocatalytic Activity for Thermo- and Photo-Switchable Cup-Stacked Carbon Nanofiber Electrodes Modified with Phase Transition Polymer and Heme Peptide.

Empowering biocatalyst-modified electrodes with the ability to both enforce and perceive will enable the development of intrinsically switchable bioelectrode systems, which exhibit autonomous and heteronomous actions specific to living organisms. However, the electrocatalytic activity of switchable bioelectrodes reported so far has been controlled by changes in the rate of substrate transport to biocatalysts. Here, we prepared a cup-stacked carbon nanofiber (CSCNF) electrode modified with a thermoresponsive N-isopropylacrylamide-based polymer containing peroxidase model compounds (HP). As CSCNFs worked as a converter from near-infrared (NIR) light to heat, bioelectrocatalytic activity of the electrode to H2O2 reduction was reversibly controlled by changes in the amount of electroactive HP, based on expanded and contracted states of the polymers induced by not only environmental temperature changes but also external NIR light irradiation. This intrinsically switchable bioelectrode technique would hold promise for adding new performances in electrochemical biosensors and biofuel cells, for example, autonomous and heteronomous tunable sensitivity and capacity.

Understanding the Carbon Additive/Sulfide Solid Electrolyte Interface in Nickel-Rich Cathode Composites and Prioritizing the Corresponding Interplay between the Electrical and Ionic Conductive Networks to Enhance All-Solid-State-Battery Rate Capability.

All-solid-state lithium batteries, including sulfide electrolytes and nickel-rich layered oxide cathode materials, promise safer electrochemical energy storage with high gravimetric and volumetric densities. However, the poor electrical conductivity of the active material results in the requirement for additional conducive additives, which tend to react negatively with the sulfide electrolyte. The fundamental scientific principle uncovered through this work is simple and suggests that the electrical network benefits associated with the introduction of short-length carbons will eventually be overpowered by the increase in bulk resistance associated with their instability in the sulfide electrolyte. However, applying just the right amount of short carbon fibres minimizes degradation of the sulfide solid electrolyte and maximizes the electron movement. Therefore, we propose the application of a low-weight-percent carbon nanotubes (CNTs) coating on the nickel-rich cathode LiNi0.8Co0.1Mn0.1O2 (NCM811) along with large-aspect-ratio carbon nanofibers (CNFs) as the primary conductive additive. When only 0.3 wt % CNTs was utilized with 4.7 wt % CNFs, an initial Coulombic efficiency of 83.55% at 0.05C and a notably excellent capacity retention of 90.1% over 50 cycles at 0.5C were achieved along with a low ionic resistance. This work helps to confirm the validity of applying short carbon pathways in sulfide-electrolyte-based cathode composites and proposes their combination with a larger primary carbon additive as a solution to the ongoing all-solid-state battery rate and instability issues.