Hierarchical Bi2O3 nanosheets and ZIF-8 derived porous nitrogen-doped carbon fibers as novel assembled nanocomposites for high-performance flexible supercapacitors.

The unique design of the core-shell heterostructure is significant for obtaining electrode materials with excellent electrochemical properties. In this paper, porous carbon nanofibers (NPC@PPZ) embedded with N-doped porous carbon nanoparticles are used to construct flexible electrodes (NPC@PPZ@Bi2O3). Zeolite imidazole skeleton (ZIF)-8 and poly(methyl methacrylate) (PMMA) derived porous carbon fibers and Bi2O3 nanosheets, were utilized as the porous core and multilayer shell, respectively. The unique core and shell result in abundant pores and channels for fast ion transport and storage, high specific surface area, and additional electroactive sites. This perfect structural design enables the NPC@PPZ@Bi2O3 composite electrode to have excellent electrochemical performance. The results show that this electrode can obtain a high specific capacitance of 697 F g-1 at a current density of 1 A g-1 and a stable cycling performance at a high current density of 5 A g-1. The strategy developed in this study provides a new approach for the design and fabrication of flexible supercapacitors by electrostatic spinning combined with hierarchical porous structures.

Multiplex electrochemical aptasensor for the simultaneous detection of linomycin and neomycin antibiotics.

The escalating use of antibiotics across diverse sectors, including human healthcare, agriculture, and livestock, has led to their pervasive presence in the environment, raising concerns about their impact on ecosystems and human health. Traditional detection methods, reliant on high-performance liquid chromatography and immuno-assays, face challenges of complexity, cross-reactivity, and limited specificity. Aptamer-based biosensors offer a promising alternative, leveraging the specificity, stability, and cost-effectiveness of aptamers. Herein, we present a novel dual-screen-printed carbon electrode (SPCE) biosensor, modified with a nanocomposite of gold nanoparticles (AuNPs) and carbon nanofibers (CNFs), for the label-free electrochemical detection of lincomycin and neomycin antibiotics. Lincomycin and neomycin, two antibiotics of environmental concern due to their widespread usage and potential ecological impact, were simultaneously detected using square wave voltammetry. The aptasensors showed high sensitivity with detection limits of 0.02 pg/mL and 0.035 pg/mL for lincomycin and neomycin, respectively. The developed biosensor exhibited high selectivity and reproducibility in detecting both antibiotics. This multiplex biosensing platform offers a promising strategy for efficient and cost-effective monitoring of antibiotic residues in environmental samples, addressing the critical need for robust detection methods in environmental monitoring and public health surveillance.

Partial oxidation of Rh/Ru nanoparticles within carbon nanofibers for high-efficiency hydrazine oxidation-assisted hydrogen generation.

Hydrazine oxidation reaction (HzOR), an alternative to oxygen evolution reaction, effectively mitigates hydrazine pollution while achieving energy-efficient hydrogen production. Herein, partially oxidized Ru/Rh nanoparticles embedded in carbon nanofibers (CNFs) are fabricated as a bifunctional electrocatalyst for hydrogen evolution reaction (HER) and HzOR. The presence of multiple components including metallic Ru and Rh and their oxides provides numerous electrochemically active sites and superior charge transfer properties, thus improving the electrocatalytic performance. Additionally, the confinement of the active components within CNFs further enhances structural stability. Consequently, the optimized electrocatalyst exhibits ultralow overpotentials of 16 mV at 10 mA cm-2 and 176 mV to reach an industry-level current density of 1 A cm-2 for HER, considerably outperforming the benchmark Pt/C catalyst. Furthermore, it shows an outstanding anodic HzOR activity, achieving a small potential of -0.019 V to generate 10 mAcm-2. A two-electrode overall hydrazine splitting (OHzS) cell prepared using the electrocatalyst operates at a compelling voltage that is 1.953 V lower than that of the overall water splitting (OWS) cell at 200 mA cm-2. Furthermore, the OHzS cell achieves a hydrogen production rate of 1.17 mmol h-1, which is 15-fold that of OWS. Additionally, Rh1Ru1Ox-CNFs-350 is used to construct a Zn-hydrazine battery with excellent performance. This study presents an effective system for achieving high-yielding green H2 production with low energy consumption while simultaneously addressing hydrazine pollution.

Electrospun mesoporous Ni0.5Zn0.5Fe2O4 - CNT - hollow carbon ternary composite nanofibers as high performance electrodes for advanced symmetric supercapacitors.

Despite being potential electrode materials for supercapacitors, Spinel ferrites suffer from poor electronic conductivity and low specific capacity. We have addressed this limitation by synthesizing composite hollow carbon nanofibers (HCNF) embedded with nanostructured Nickel Zinc Ferrite (NZF) and Multiwalled carbon nanotubes (CNT), through coaxial electrospinning. These ternary composite nanofibers NZF-CNT-HCNF have a high specific capacity of 833 C g-1 at a current density of 1 A g-1 and have a capacity retention of 90% after 3000 cycles. This is much better than that of pure NZF fibers (180 C g-1) or hollow carbon nanofibers (96 C g-1), suggesting synergy between various constituents of the composite. A symmetric supercapacitor fabricated from NZF-CNT-HCNF composite nanofibers (30% NZF) has a high specific capacity of 302 C g-1 (302 A g-1) at a current density of 1 A g-1 and has a capacity retention of 95% after 5000 cycles. At the same current density, the device has a high energy density of 39 Whkg-1 and power density of 1000 Wkg-1 at a current density of 1 A g-1. This performance can be attributed to high specific surface area (776 m2 g-1), mesoporosity (pore size ~ 4 nm) and high electrical conductivity of CNTs..

Adsorptive removal of organophosphate pesticides from aqueous solution using electrospun carbon nanofibers.

Organophosphate pesticides (OPPs) are widely prevalent in the environment primarily due to their low cost and extensive use in agricultural lands. However, it is estimated that only about 5% of these applied pesticides reach their intended target organisms. The remaining 95% residue linger in the environment as contaminants, posing significant ecological and health risks. This underscores the need for materials capable of effectively removing, recovering, and recycling these contaminants through adsorption processes. In this research, adsorbent materials composed of electro-spun carbon nanofibers (ECNFs) derived from polyacrylonitrile was developed. The materials were characterized through several techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) analysis, and contact angle measurements. SEM analysis revealed details of the structural properties and inter-fiber spacing variations of the carbon nanofibers. The results revealed that ECNFs possess remarkable uniformity, active surface areas, and high efficiency for adsorption processes. The adsorption studies were conducted using batch experiments with ethion pesticide in aqueous solution. High-Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) was utilized to quantify the concentrations of the OPP. Various parameters, including adsorbent dosage, pH, contact time, and initial ethion concentration, were investigated to understand their impact on the adsorption process. The adsorption isotherm was best described by the Freundlich model, while the kinetics of adsorption followed a non-integer-order kinetics model. The adsorption capacity of the ECNFs for OPP removal highlights a significant advancement in materials designed for environmental remediation applications. This study demonstrates the potential of ECNFs to serve as effective adsorbents, contributing to the mitigation of pesticide contamination in agricultural environments.

Solid-state Ru(bpy)32+ electrochemiluminescence sensor for trace detection of fenpropathrin using loofah sponge-like carbon nanofibers and CdS.

Loofah sponge-like carbon nanofibers (LF-Co,N/CNFs) were utilized as a carrier for Ru(bpy)32+, and then combined with CdS to create a novel solid-state electrochemiluminescence sensor capable of detecting trace amounts of fenpropathrin. LF-Co,N/CNFs, obtained through the high-temperature pyrolysis of ZIF-67 coaxial electrospinning fibers, were characterized by a loofah-like morphology and exhibited a significant specific surface area and porosity. Apart from serving as a carrier, LF-Co,N/CNFs also functioned as a luminescence accelerator, enhancing the system's luminescence efficiency by facilitating electron transmission and reducing the transmission distance. The inclusion of CdS in the luminescence reaction, in conjunction with Ru(bpy)32+, further boosted the sensor's luminescence signal. The resulting sensor demonstrated a satisfactory signal, with fenpropathrin causing significant quenching of the ECL signal. Under optimized conditions, a linear relationship between the signal quench value and fenpropathrin concentration in the range 1 × 10-12 to 1 × 10-6 M was observed, with a detection limit of 3.3 × 10-13 M (S/N = 3). This developed sensor is characterized by its simplicity, sensitivity, and successful application in detecting fenpropathrin in real samples. The study not only presents a straightforward detection platform for fenpropathrin but also introduces new avenues for the rapid determination of various food contaminants, thereby expanding the utility of carbon fibers in electrochemiluminescence sensors.

Copper dual-doping strategy of porous carbon nanofibers and nickel fluoride nanorods as bi-functional oxygen electrocatalysis for effective zinc-air batteries.

Designing and developing efficient, low-cost bi-functional oxygen electrocatalysts is essential for effective zinc-air batteries. In this study, we propose a copper dual-doping strategy, which involves doping both porous carbon nanofibers (PCNFs) and nickel fluoride nanoparticles with copper alone, successfully preparing copper-doped nickel fluoride (NiF2) nanorods and copper nanoparticles co-modified PCNFs (Cu@NiF2/Cu-PCNFs) as an efficient bi-functional oxygen electrocatalyst. When copper is doped into the PCNFs in the form of metallic nanoparticles, the doped elemental copper can improve the electronic conductivity of composite materials to accelerate electron conduction. Meanwhile, the copper doping for NiF2 can significantly promote the transformation of nickel fluoride nanoparticles into nanorod structures, thus increasing the electrochemical active surface area and enhancing mass diffusion. The Cu-doped NiF2 nanorods also possess an optimized electronic structure, including a more negative d-band center, smaller bandgap width and lower reaction energy barrier. Under the synergistic effect of these advantages, the obtained Cu@NiF2/Cu-PCNFs exhibit outstanding bi-functional catalytic performances, with a low overpotential of 0.68 V and a peak power density of 222 mW cm-2 in zinc-air batteries (ZABs) and stable cycling for 800 h. This work proposes a one-step way based on the dual-doping strategy, providing important guidance for designing and developing efficient catalysts with well-designed architectures for high-performance ZABs.

A Review of Carbon Nanofiber Materials for Dendrite-Free Lithium-Metal Anodes.

Lithium metal is regarded as ideal anode material due to its high theoretical specific capacity and low electrode potential. However, the uncontrollable growth of lithium dendrites seriously hinders the practical application of lithium-metal batteries (LMBs). Among various strategies, carbon nanofiber materials have shown great potential in stabilizing the lithium-metal anode (LMA) due to their unique functional and structural characteristics. Here, the latest research progress on carbon nanofibers (CNFs) for LMA is systematically reviewed. Firstly, several common preparation techniques for CNFs are summarized. Then, the development prospects, strategies and the latest research progress on CNFs for dendrite-free LMA are emphatically introduced from the perspectives of neat CNFs and CNF-based composites. Finally, the current challenges and prospects of CNFs for stabilizing LMA are summarized and discussed. These discussions and proposed strategies provide new ideas for the development of high-performance LMBs.

Nanoengineered electrochemical sensor for sensitive detection of carbendazim in environmental waters using Er3NbO7/f-CNF nanocomposite.

Water contamination by agricultural chemicals is a pressing environmental issue today. Carbendazim (CBZ), a potent fungicide with broad-spectrum antifungal properties and significant toxicity, poses substantial risks to ecosystems and human health. This study introduces an advanced electrochemical sensor by modifying screen-printed carbon electrodes (SPCEs) with a nanocomposite of erbium niobate (Er3NbO7) and functionalized carbon nanofibers (f-CNF). The Er3NbO7/f-CNF nanocomposite enhances electrochemical performance through its high surface area, excellent electrical conductivity, and catalytic activity. This synergy results in exceptional attributes such as a low detection limit of 6.0 nmolL-1, low quantification limit of 19.98 nmolL-1, sensitivity of 3.522 µAµ(molL-1)-1.cm-2, and precision of 0.05%. The sensor demonstrates a wide linear range from 0.2 to 222 µmolL-1, combined with high selectivity and robust stability, making it suitable for precise CBZ detection. Successful deployment in environmental monitoring underscores its versatility and effectiveness in safeguarding human health and ecological balance, establishing it as a pivotal tool in environmental protection efforts.

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.

Solid electrochemiluminescence sensor by immobilization luminol in Zn-Co-ZIF CNFs for sensitive detection of procymidone in vegetables.

A solid-state electrochemiluminescence (ECL) sensor was fabricated by immobilizing luminol, a classical luminescent reagent, on a Zn-Co-ZIF carbon fiber-modified electrode for the rapid and sensitive detection of procymidone (PCM) in vegetable samples. The sensor was created by sequentially modifying the glassy carbon electrode with Zn-Co-ZIF carbon fiber (Zn-Co-ZIF CNFs), Pt@Au NPs, and luminol. Zn-Co-ZIF CNFs, prepared through electrospinning and high-temperature pyrolysis, possessed a large specific surface area and porosity, making it suitable as carrier and electron transfer accelerator in the system. Pt@Au NPs demonstrated excellent catalytic activity, effectively enhancing the generation of active substances. The ECL signal was significantly amplified by the combination of Zn-Co-ZIF CNFs and Pt@Au NPs, which can subsequently be diminished by procymidone. The ECL intensity decreased proportionally with the addition of procymidone, displaying a linear relationship within the concentration range 1.0 × 10-13 to 1.0 × 10-6 mol L-1 (R2 = 0.993). The sensor exhibited a detection limit of 3.3 × 10-14 mol L-1 (S/N = 3) and demonstrated outstanding reproducibility and stability, making it well-suited for the detection of procymidone in vegetable samples.

The effect of using two stabilization temperatures and fixation process on preparation of carbon nanofibers.

Carbon nanofibers (CNFs) are prepared from electrospun polyacrylonitrile (PAN) because of their high carbon content. Heat treatment (oxidative stabilization and carbonization) is necessary to convert PAN nanofibers into CNFs. The fixation of fibrous structure of polymer precursor during heat treatment is always considered as a problem. The aim of this work is to study the effects of two different stabilization temperatures and fixation on CNFs prepared from electrospun PAN nanofibers. In this study, we use two different stabilization temperatures (275 and 300 °C) to investigate the effect of temperature on the oxidation, cyclization, crosslinking, aromatization, and dehydrogenation processes that occur during the stabilization heat treatment. Further, we study the effect of electrospun sheet fixation during heat treatment on the fibrous structure of electrospun fibers and methods to prevent shrinkage and folding of the electrospun sheet. Fourier transform infrared spectroscopy revealed the effectiveness of stabilization at 300 °C when transforming PAN elctrospun nanofibers to CNFs. Raman spectroscopy showed that carbonization at 800 °C after stabilization at 300 °C lowers the R-value (ID/IG ratio) comparing with that stabilized at 275 °C which indicates increasing the amount of structurally ordered graphite crystallites relative to the disordered structure. Scanning electron microscopy (SEM) revealed that fixation process maintained a uniform fibrous structure for the stabilized sheets without shrinkage, whereas carbonization at 800 °C without fixation resulted in deformed and folded carbonized PAN with loss in the fibrous structure.

Improving the Oxidation Resistance of Phenolic Resin Pyrolytic Carbons by In Situ Catalytic Formation of Carbon Nanofibers via Copper Nitrate.

Phenolic resin pyrolytic carbons were obtained by catalytic pyrolysis of phenolic resin at 500 °C, 600 °C, 700 °C, and 800 °C for 3 h in an argon atmosphere using copper nitrate as a catalyst precursor. The effects of copper salts on the pyrolysis process of phenolic resin as well as the structural evolution and oxidation resistance of phenolic resin pyrolytic carbons were studied. The results showed that copper oxide (CuO) generated from the thermal decomposition of copper nitrate was reduced to copper (Cu) by the gas generated from the thermal decomposition of the phenolic resin. Carbon nanofibers with tapered structures were synthesized by Cu catalysis of pyrolysis gas at 500-800 °C. The catalytic pyrolysis of phenolic resin with Cu increased the graphitization degree and reduced the pore volume of the phenolic resin pyrolytic carbons. The combined action improved the oxidation resistance of phenolic resin pyrolytic carbons.

The Effect of Carbon Nanofibers on the Mechanical Performance of Epoxy-Based Composites: A Review.

This review is a fundamental tool for researchers and engineers involved in the design and optimization of fiber-reinforced composite materials. The aim is to provide a comprehensive analysis of the mechanical performance of composites with epoxy matrices reinforced with carbon nanofibers (CNFs). The review includes studies investigating the static mechanical response through three-point bending (3PB) tests, tensile tests, and viscoelastic behavior tests. In addition, the properties of the composites' resistance to interlaminar shear strength (ILSS), mode I and mode II interlaminar fracture toughness (ILFT), and low-velocity impact (LVI) are analyzed. The incorporation of small amounts of CNFs, mostly between 0.25 and 1% by weight was shown to have a notable impact on the static and viscoelastic properties of the composites, leading to greater resistance to time-dependent deformation and better resistance to creep. ILSS and ILFT modes I and II of fiber-reinforced composites are critical parameters in assessing structural integrity through interfacial bonding and were positively affected by the introduction of CNFs. The response of composites to LVI demonstrates the potential of CNFs to increase impact strength by reducing the energy absorbed and the size of the damage introduced. Epoxy matrices reinforced with CNFs showed an average increase in stiffness of 15% and 20% for bending and tensile, respectively. The laminates, on the other hand, showed an increase in bending stiffness of 20% and 15% for tensile and modulus, respectively. In the case of ILSS and ILFT modes I and II, the addition of CNFs promoted average increases in the order of 50%, 100%, and 50%, respectively.

Can Two-Dimensional Correlation Spectroscopy (2D-COS) Indicate Biocompatible Material?

Carbon nanofibers are a new type of carbon materials. One of the methods of obtaining them is the carbonization of a polymer precursor. They are attractive in many areas, including medicine, due to the possibility of modifying their properties in a wide range. For example, the conditions of the carbonization process result in the creation of materials with designed structures and surface parameters. In the current work, the nanoprecursor was polyacrylonitrile (PAN) fibers. Two types of carbon fibers obtained by carbonization of the PAN precursor at 1000 °C were tested. The first electrospun carbon nanofibers (ESCNFs) were cytotoxic, while the second ESCNF-f were biocompatible after functionalization. The parameters obtained from Raman tests did not clearly discriminate between the tested materials. Multiwavelength Raman studies, analyzed using the two-dimensional correlation spectroscopy (2D-COS), treating the laser energy as an external disturbance, showed a difference between both fibrous structures. 2D-COS indicates that structures resembling graphite systems, devoid of disordered carbon forms, are nontoxic.

Unveiling the In Situ Evolution of Li2O-Rich Solid Electrolyte Interface on CoOx Embedded Carbon Fibers as Li Anode Host.

Modification of three-dimensional (3D) carbon hosts with metal oxides has been considered as advantageous for the formation of Li2O-rich solid electrolyte interface (SEI), which can show fast Li+ diffusion, and meanwhile alleviate dendrite problems caused by fragility and nonuniformity of native SEIs. However, the lack of convincing experimental evidence has made it difficult to unveil the true origin of oxygen in Li2O-rich SEIs until now. Herein, CoOx embedded carbon nanofibers (CNF-CoOx) are successfully prepared as high-performance Li anode hosts. By employing 18O isotope labeling, the role of CoOx during SEI evolution is elucidated, revealing that CoOx contributes significantly to Li2O formation by delivering oxygen. Benefiting from the rich Li2O content, the as-formed SEIs greatly improve the Li+ migration kinetics, and therefore, the CNF-CoOx@Li anode can exhibit excellent cycling stability in half, symmetrical, and full cells.

A Review of Electrospun Carbon-Based Nanofibers Materials used in Lithium-Sulfur Batteries.

Commercial lithium-ion batteries are gradually approaching their theoretical specific energy, which cannot meet the fast-growing energy storage demands. Lithium-sulfur (Li-S) batteries are anticipated to supersede lithium-ion batteries as the next-generation energy storage system owing to their high atheoretical specific capacity (1675 mAh g-1) and energy density (2600 Wh kg-1). Nonetheless, Li-S batteries encounter several challenges, including the inadequate conductivity of sulfur and lithium sulfide, sulfur's volume expansion, and the shuttle effect of lithium polysulfides, all of which significantly impact the practical utilization of Li-S batteries. Electrospun carbon-based nanofibers can simultaneously resolve these issues with their economical preparation, distinctive nanostructure, and exceptional flexibility. This review presents the most recent research findings on electrospun carbon-based nanofibers materials serving as sulfur hosts and interlayer components in Li-S batteries. We analyzed the impact of the material's structural design on the performance of Li-S batteries and the relative underlying mechanism. Finally, the current challenges and issues faced by carbon-based nanofibers composites in the application of Li-S batteries are summarized, and the future development trajectory are outlined.

A Hybrid Structure to Improve Electrochemical Performance of SiO Anode Materials in Lithium-Ion Battery.

The wide utilization of lithium-ion batteries (LIBs) prompts extensive research on the anode materials with large capacity and excellent stability. Despite the attractive electrochemical properties of pure Si anodes outperforming other Si-based materials, its unsafety caused by huge volumetric expansion is commonly admitted. Silicon monoxide (SiO) anode is advantageous in mild volume fluctuation, and would be a proper alternative if the low initial columbic efficiency and conductivity can be ameliorated. Herein, a hybrid structure composed of active material SiO particles and carbon nanofibers (SiO/CNFs) is proposed as a solution. CNFs, through electrospun processes, serve as a conductive skeleton for SiO nanoparticles and enable SiO nanoparticles to be uniformly embedded in. As a result, the SiO/CNF electrochemical performance reaches a peak at 20% the mass ratio of SiO, where the retention rate reaches 73.9% after 400 cycles at a current density of 100 mA g-1, and the discharge capacity after stabilization and 100 cycles are 1.47 and 1.84 times higher than that of pure SiO, respectively. A fast lithium-ion transport rate during cycling is also demonstrated as the corresponding diffusion coefficient of the SiO/CNF reaches ~8 × 10-15 cm2 s-1. This SiO/CNF hybrid structure provides a flexible and cost-effective solution for LIBs and sheds light on alternative anode choices for industrial battery assembly.

Growth of Carbon Nanofibers and Carbon Nanotubes by Chemical Vapour Deposition on Half-Heusler Alloys: A Computationally Driven Experimental Investigation.

The possibility of directly growing carbon nanofibers (CNFs) and carbon nanotubes (CNTs) on half-Heusler alloys by Chemical Vapour Deposition (CVD) is investigated for the first time, without using additional catalysts, since the half-Heusler alloys per se may function as catalytic substrates, according to the findings of the current study. As a carbon source, acetylene is used in the temperature range of 700-750 °C. The n-type half-Heusler compound Zr0.4Ti0.60.33Ni0.33Sn0.98Sb0.020.33 is utilized as the catalytic substrate. At first, a computational model is developed for the CVD reactor, aiming to optimize the experimental process design and setup. The experimental process conditions are simulated to investigate the reactive species concentrations within the reactor chamber and the activation of certain reactions. SEM analysis confirms the growth of CNFs with diameters ranging from 450 nm to 1 µm. Raman spectroscopy implies that the formed carbon structures resemble CNFs rather than CNTs, and that amorphous carbon also co-exists in the deposited samples. From the characterization results, it may be concluded that a short reaction time and a low acetylene flow rate lead to the formation of a uniform CNF coating on the surface of half-Heusler alloys. The purpose of depositing carbon nanostructures onto half-Heusler alloys is to improve the current transfer, generated from these thermoelectric compounds, by forming a conductive coating on their surface.

Elucidating the enduring transformations in cellulose-based carbon nanofibers through prolonged isothermal treatment.

This study investigates the conversion of highly acetylated sugarcane bagasse into high-modulus carbon nanofibers (CnNFs) with exceptional electrical conductivity. By electrospinning the bagasse into nanofibers with diameters ranging from 80 nm to 800 nm, a cost-effective CnNFs precursor is obtained. The study reveals the transformation of the cellulose crystalline structure into a stable antiparallel chain arrangement of cellulose II following prolonged isothermal treatment, leading to a remarkable 50 % increase in CnNFs recovery with carbon contents ranging from 80 % to 90 %. This surpasses the performance of any other reported biomass precursors. Furthermore, graphitization-induced shrinkage of CnNFs diameter results in significant growth of specific surface area and pore volume in the resulting samples. This, along with a highly ordered nanostructure and high crystallinity degree, contributes to an impressive tensile modulus of 9.592 GPa, surpassing that of most petroleum-based CnNFs documented in the literature. Additionally, the prolonged isothermal treatment influences the d002 value (measured at 0.414 nm) and CnNFs degree of crystallinity, leading to an enhancement in electrical conductivity. However, the study observes no size effect advantages on mechanical properties and electrical conductivity, possibly attributed to the potential presence of point defects in the ultrathin CnNFs. Overall, this research opens a promising and cost-effective pathway for converting sugarcane biomasses into high-modulus carbon nanofibers with outstanding electrical conductivity. These findings hold significant implications for the development of sustainable and high-performance materials for various applications, including electronics, energy storage, and composite reinforcement.