Search Results (364)

Iron-based carbon nanofibers (Fe-CNFs) have garnered significant attention due to their promising applications as functional materials or precursors in the field of catalysis, energy storage, and electromagnetic interference shielding. In this work, electrospun Fe₃O₄-CNFs were reduced under a H₂/Ar atmosphere to obtain Fe-CNFs, and the reduction temperature and holding time were systematically optimized. Notably, a pronounced carbon gasification phenomenon was observed at elevated temperatures (>550 °C), leading to a complete consumption of the carbon matrix. The underlying mechanism was explored using temperature-programmed reduction with mass spectrometry (TPR-MS) and density functional theory (DFT) calculations. The results suggest that the carbon gasification during the H₂ reduction process is primarily driven by the carbon-water reaction, which can be catalyzed by the in situ-formed Fe nanoparticles. As the temperature increases, various reactions—including hydrogen dissociation, H₂ spillover, carbon-water reaction, and Boudouard reaction—may progressively consume the carbon framework, ultimately leading to structural collapse and complete material loss. This study elucidates the underlying mechanism of carbon-water reaction and provides practical guidance for the optimization of synthesis parameters, thereby enhancing the yield and structural integrity of free-standing Fe-CNFs for their application in catalysis and energy storage-related fields. Full article

As global energy demand continues to rise and the need for environmental conservation grows more urgent, solar energy has attracted substantial attention owing to its inherent cleanliness and sustainability. Perovskite solar cells (PSCs), an innovative photovoltaic technology, have shown significant improvements in photoelectric conversion efficiency (PCE) since their introduction. Nevertheless, significant challenges remain in enhancing efficiency and ensuring long-term stability. Naturally abundant and environmentally benign carbon materials represent a promising alternative. Incorporating carbon materials into PSCs can yield beneficial effects, such as controlling the crystallization rate of the perovskite layer, improving carrier transport properties, and realizing interface modification between various functional layers. This review systematically reviews the application of carbon materials in PSCs, including carbon nanotubes (CNT s), carbon dots (CDs), carbon nanofibers (CNFs), fullerenes, and their derivatives, thereby contributing to sustainable development by enhancing resource efficiency, device stability, and environmental compatibility of PSCs. Full article

In the present study, a kinetic model was developed for the process of oxidative desulfurization of light gas oil with 7329 ppm sulfur using a newly synthesized nanocomposite catalyst. The batch reactor experiments were conducted at different thermal conditions (313–373 K) and reaction times (30–90 min) to explain this endeavor of desulfurization performance as a function of these variables, targeting the design of a reliable reactor system. Carbon nanofibers (CNFs) were integrated into the support γ-Al₂O₃ at various concentrations of 5%, 7.5%, and 10% to improve mechanical properties, surface area, and distribution of active metals. The nanocomposite support was impregnated with molybdenum trioxide (MoO₃) and iron oxide (Fe₂O₃) to form four variants of the catalyst: CAT-1 with 10% MoO₃ + 5% Fe₂O₃/Al₂O₃ + 5% CNF, CAT-2 with 10% MoO₃ + 5% Fe₂O₃/Al₂O₃ + 7.5% CNF, CAT-3 with 10% MoO₃ + 5% Fe₂O₃/Al₂O₃ + 10% CNF, and CAT-4 with 10% MoO₃ + 5% Fe₂O₃/Al₂O₃ with no CNF. CAT-3 had the best effectiveness for sulfur removal with 87.5% at 373 K and a reaction time of 90 min. The model predicts a maximum sulfur removal rate of 99.86% under optimal conditions of 550 K and 200 min (for an initial sulfur concentration of 7329 ppm). The experimental and modeling results therefore indicate the potential of the developed catalyst system, while the optimum condition at 550 K and 200 min should be interpreted as a model-predicted outcome. The development of such highly efficient nanocatalysts for deep desulfurization is a crucial advancement in green chemistry, directly contributing to the production of cleaner fuels to mitigate air pollution and supporting the aims of the United Nations Sustainable Development Goals (SDGs), particularly SDG 9 (Industry, Innovation, and Infrastructure) and SDG 12 (Responsible Consumption and Production). From a sustainability perspective, the proposed ODS system supports cleaner fuel production and reduced sulfur-derived emissions, while operating-condition optimization helps improve process efficiency in support of more sustainable refining strategies. Full article

Hydrogels have emerged as a crucial category of polymeric materials in materials science due to their three-dimensional network structure and remarkable capacity for water absorption and retention. However, conventional single-function hydrogels do not satisfy the increasing demands of advanced applications in biomedicine and environmental engineering. This paper focuses on the design, preparation, and performance characterization of nanofiber-reinforced polyacrylamide hydrogels to overcome this limitation. A bilayer structure, consisting of tensile layers and actuator layers based on a polyacrylamide/sodium alginate (PAM/SA) matrix integrated with functional materials, was developed. Nanocellulose (CNF) was incorporated to regulate mechanical properties by adjusting its content ratio with PAM, while poly-N-isopropylacrylamide (PNIPAM) and multi-walled carbon nanotubes (MWCNTs) were added to confer photothermal responsiveness. The deformation of the hydrogel was induced by temperature changes resulting from infrared illumination. The results indicate that the CNF-reinforced hydrogels exhibit enhanced mechanical strength—with the tensile strength reaching 17 kPa (89% higher than pure PAM) and fracture strain approaching 900% when the CNF content is 0.44 wt.% and PAM/SA mass ratio is 4:1—and they display reversible thermosensitive responses (reaching 60 °C within 100 s under near-infrared irradiation) following the incorporation of carbon nanotubes. This paper presents a novel strategy for the development of multifunctional hydrogel-based actuated systems, expanding the application potential of hydrogels in human motion tracking and drug delivery. Full article

Electrical stimulation enhances functionality and accelerates maturation in biofabricated tissues, which are particularly important for muscle tissue engineering applications. Accordingly, there is demand for 3D-printable electrically conductive cytocompatible scaffolds that enable patient-specific geometries and localized electrical stimulation, as well as incorporate further maturation-promoting geometrical cues. Filament-based scaffolds from fused filament fabrication could overcome current limitations in geometric freedom, size and partially cytotoxic additives. In this study, biodegradable polylactic acid (PLA)-based conductive filaments incorporating graphene nanoplatelets (GNPs) or carbon nanofibers (CNFs) were developed via melt-mixing extrusion to possibly enable the electrical functionalization of muscle scaffolds. A two-stage process combining twin-screw and single-screw extrusion was preferred to allow for higher filler incorporation. Filament morphology, printability, electrical conductivity, and cytocompatibility were systematically evaluated. Homogeneous filaments containing up to 16 wt.% GNPs or 3.6 wt.% CNFs were successfully produced and processed by fused filament fabrication into scaffold geometries supporting myoblast orientation. Electrical conductivity was measured above 16 wt.% GNPs, with up to 2.7 µS/m, with printed constructs capable of connecting a circuit. GNP-based filaments were cytocompatible, supporting myoblast attachment and elongated morphology. An adjustable electrical stimulation setup demonstrated improved muscle maturation and contractile responses of C2C12 myoblasts, highlighting biodegradable conductive filaments’ potential for electrically active muscle tissue scaffolds. Full article

In the present work, the elastic modulus of several types of polymer nanocomposites has been analyzed with a semiempirical model which takes into consideration agglomerate formation and their impact on the nanocomposites’ mechanical performance. The nanocomposites under investigation were either hybrids with a combination of graphene oxide (GO) with multi-walled carbon nanotubes (MWCNTs) or carbon nanofibers (CNFs) at various loadings, or monofillers with varying nanoparticle sizes, at a constant nanofiller loading. In addition, the effect of the type of polymeric matrix on the same nanofiller combinations has been examined. The basic assumption of two phases, namely a matrix with finely dispersed nanoparticles coexisting with agglomerates, was analyzed. The elastic stiffness of the first phase was calculated by the Mori–Tanaka model, and hereafter a semiempirical model was utilized for the estimation of the agglomerates’ stiffness. Within the context of this model, it was shown that the agglomerates’ volume fraction, combined with the nanoparticles’ density, namely the nanoparticles’ volume fraction in the agglomerates and consequently the inclusions’/agglomerates’ enhanced modulus, may cause a substantial improvement in the Young’s modulus, which cannot be explained by conventional mechanical models. These results apply to both nanocomposite types, hybrids at various nanofiller loadings and monofillers with varying particle sizes. Full article

Carbon-based bifunctional oxygen electrocatalysts with rationally designed architectures are essential for high-performance rechargeable zinc–air batteries (ZABs), yet the concurrent optimization of catalytic activity, durability, and mass transport remains challenging. Herein, hierarchical ZnCo carbon nanofibers/carbon nanotubes (CNFs@CNTs) are fabricated via single-nozzle electrospinning followed by melamine-assisted pyrolysis under a ZnCl₂-regulated atmosphere. During thermal treatment, Co species embedded within carbon nanofibers catalyze in situ carbon nanotube growth, while ZnCl₂ vapor modulates the carbonization process and surface chemistry, collectively generating a hierarchical CNFs@CNTs architecture with high surface area and abundant exposed active sites. As a result, ZnCo CNFs@CNTs exhibit outstanding bifunctional ORR/OER activity, surpassing Zn-free and Co-free counterparts. Combined structural and electrochemical analyses reveal that the synergistic interaction between Co active centers and Zn-assisted carbon structural regulation enhances reaction kinetics and long-term stability. When implemented as air electrodes in rechargeable ZABs, ZnCo CNFs@CNTs deliver high power density, reduced charge–discharge polarization, and excellent cycling durability, demonstrating strong practical applicability. This work presents an effective strategy for constructing hierarchical CNFs@CNTs composites via electrospinning and dual-component thermal regulation, offering new insights into the design of high-efficiency bifunctional air electrodes for advanced ZABs. Full article

Flexible supercapacitors have attracted significant attention as promising power sources for portable and wearable electronic devices. However, achieving simultaneous high power density, energy density and long-term cyclic stability in a simple device configuration remains a critical challenge. Herein, we report an all-solid-state flexible planar supercapacitor based on hierarchically structured cellulose nanofiber-carbon nanotube@manganese dioxide (CNF-CNT@MnO₂) composite aerogels. The electrode architecture is rationally designed by first dispersing CNTs within a hydrophilic CNF scaffold to form a conductive three-dimensional network, followed by in situ oxidative polymerization of MnO₂ onto the CNF-CNT fibrous skeleton. The hydrophilic CNFs network ensures thorough electrolyte penetration, the interconnected CNTs facilitate rapid electron transport, and the uniformly coated MnO₂ layer provides substantial pseudocapacitance. The aerogel electrode with a low density of 14.6 mg cm⁻³ and a high specific surface area of 214.4 m² g⁻¹ delivers a specific capacitance of 273.0 F g⁻¹ at 0.4 A g⁻¹. The assembled planar supercapacitor, incorporating gel electrolyte and a flexible hydrogel substrate, achieves an impressive areal capacitance of 885.0 mF cm⁻² at 2 mA cm⁻², energy density of 122.9 μWh cm⁻² and corresponding power density of 1000.0 μW cm⁻². The device exhibits excellent electrochemical stability, retaining 83.3% capacitance after 2500 charge–discharge cycles, and outstanding mechanical flexibility, with 96.3% capacitance retention after 200 repeated bending cycles. Furthermore, multiple devices can be connected in series or parallel to proportionally increase output voltage or current, meeting the practical power requirements of electronic applications. This work offers a viable pathway toward high-performance, durable energy storage solutions for next-generation wearable electronics. Full article

As photovoltaic modules advance toward higher efficiency, environmental sustainability and carbon emission reduction in materials have become important issues. In this study, large-area transparent films were fabricated using TEMPO-oxidized cellulose nanofibers (CNFs), and their feasibility as replacements for conventional petroleum-based polymer films in photovoltaic module materials was evaluated. The CNF films were stably fabricated under large-area processing conditions with uniform thickness. The CNF films exhibited high optical transmittance in the visible region comparable to commercial polymer films, sufficient mechanical stiffness, and thermal stability under module lamination conditions. Module-level performance analysis showed that the effect of CNF film application depended on the application position, with different output trends for front and rear configurations. These results demonstrate the potential of large-area CNF films as sustainable photovoltaic module materials and their contribution to carbon emission reduction through the use of renewable bio-based resources. Full article

Thermal interface materials are critical components for ensuring efficient heat dissipation in thermal management systems. The current research focus is to fabricate thermal interface materials (TIMs) that demonstrate high thermal conductivity while at low filler loadings. In this study, an aligned, thermally conductive skeleton was fabricated via the freeze casting method, utilizing carbon nanofibers (CNFs) and nickel (Ni) particles. This skeleton was subsequently infiltrated with silicone rubber (SR) to obtain the polymer composite. Within the aligned skeleton, CNFs and Ni particles are densely packed, with the Ni particles acting as conductive bridges between adjacent CNFs. This bridging effect facilitates a substantial enhancement in the overall thermal conductivity with only a minimal addition of Ni. By combining the skeleton’s microstructure with thermal performance, the effects of key parameters on thermal conductivity were systematically investigated. A maximum thermal conductivity improvement of 64.8% was achieved by hybridizing CNFs with a small amount of Ni (1.09 vol%) compared to the CNF-only counterpart. Furthermore, at a low total loading (8.02 vol% CNFs and 1.09 vol% Ni), the composite achieved a thermal conductivity of 3.30 W/(m·K). This value was 47.2% higher than that of a CNF-only TIM and 36.2% higher than that of a composite prepared by common freezing under the same filler composition. Additionally, the incorporation of Ni enhanced the composite’s thermal stability. Moreover, the composite exhibited a favorable combination of enhanced mechanical strength and excellent elasticity. Full article

A chemiresistive nitric oxide (NO) gas sensor based on Pt/WO₃ co-decorated carbon nanofibers (CNFs) was fabricated using a simple and scalable electrospinning process. This sensor demonstrates high-ppb-level NO detection at room temperature (25 °C), with an experimentally demonstrated detection limit of 100 ppb. It exhibits rapid response, good signal repeatability, excellent batch-to-batch reproducibility, and high selectivity toward NO. Compared with previously reported NO sensors, this work highlights the integration of Pt and WO₃ within a conductive CNF network, enabling room-temperature NO detection down to 100 ppb using a simple chemiresistive architecture. In addition, preliminary sensing tests were conducted using dried simulated breath samples prepared by introducing exogenous NO into exhaled breath from healthy volunteers, demonstrating the sensor’s capability to resolve different NO levels in a complex breath-related background. Owing to its reliable performance and cost-effective fabrication, the sensor holds potential as a NO sensing platform, providing a materials-level basis for future breath NO analysis and other related applications. Full article

At present, composite phase change materials are widely studied for battery thermal management. However, to ensure the battery’s thermal safety, it is necessary not only to control the temperature during regular operation, but also to prevent sudden thermal runaway. This basic function depends on the flame-retardant properties of the composite phase change materials. In this study, a hexagonal double-layer hollow nanocage S2 with defect orientation was prepared and combined with carbon nanotubes (PNT) derived from polypyrrole (PPy) tubes to form a high adsorption mixture. Multifunctional composite phase change material PNT/S2@PEG/TEP was prepared by adsorbing and coating polyethylene glycol 8000 (PEG-8000) and triethyl phosphate (TEP) with microfibrillated cellulose nanofibers (CNF) as the skeleton. The characterization shows that its thermal conductivity is 0.65 W/m·K and its phase transition enthalpy is 146.1 J/g, demonstrating its excellent thermal regulation. Microcalorimetric testing (MCC) confirmed its flame-retardant ability, attributed to the strong adsorption of PNT/S2 on PEG-8000 and TEP, the improvement in PNT’s thermal conductivity, and the contribution of CNF to flexibility. This composite phase change material, with excellent comprehensive properties, has broad application prospects in thermal safety for electronic equipment, significantly expanding its practical scope. Full article

The escalating demand for high-performance energy storage devices has driven extensive research into flexible electrode materials for supercapacitors. Integrating structured carbon nanomaterials with flexible substrates to construct binder-free electrode architectures represents a promising strategy for improving supercapacitor capacitance and rate capability. However, achieving stable, binder-free integration of structure-controlled nanostructured carbon materials with flexible substrates remains a critical challenge. In this study, we report a direct synthesis approach for one-dimensional (1D) carbon nanofibers (CNFs) on commercial flexible carbon fabric (CF) via chemical vapor deposition (CVD). The resulting CNFs exhibit two typical average diameters—approximately 25 nm and 50 nm—depending on the growth temperature, with both displaying highly graphitized structures. Electrochemical characterization of the CNFs/CF composites in 1 M H₂SO₄ electrolyte revealed typical electric double-layer capacitor (EDLC) behavior. Notably, the 25 nm-CNFs/CF electrode achieves a high specific capacitance of 87.5 F/g, significantly outperforming the 50 nm-CNFs/CF electrode, which reaches 50.2 F/g. Compared with previously reported carbon nanotube CNTs/CF electrodes, the 25 nm-CNFs/CF electrode exhibits superior capacitance and lower resistance. Full article

Silicon is considered one of the most promising anode materials for lithium-ion batteries because of its high theoretical capacity and low lithiation potential. However, its practical application is limited by significant volume expansion, unstable solid–electrolyte interphase formation, and poor intrinsic conductivity. This review summarizes recent advances in hybrid strategies using multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), graphene, carbon nanofibers (CNFs), and pitch-derived carbons. We compare their respective benefits and drawbacks regarding conductivity, structural resilience, and scalability, while also addressing critical challenges such as dispersion, defect control, and processing costs. The discussion emphasizes the importance of hierarchical, multifunctional architectures that combine different forms of carbon to achieve synergistic performance. Finally, we outline future directions in interfacial engineering, defect and doping optimization, and electrode design under high-loading conditions. We believe that this review can offer perspectives on developing durable, energy-dense, and commercially viable silicon anodes for next-generation lithium-ion batteries. Full article

This study is devoted to the determination of the role of aerosol spraying in the formation of NO₂ sensor properties of carbon nanofiber (CNF)-based films. This is the first paper to systematically apply the aerosol spraying technique to CNF-based films and link the spraying parameters directly to sensor performance metrics (response, signal-to-noise ratio, response times, etc.). Chemiresistive gas sensors were created based on CNFs and tested at room temperature (25 ± 1 °C). It has been shown that the increase in the concentration of the CNF/ethanol mixture used for spraying from 3 to 30 mg/mL led to a growth in sensor response from 1.2% to 12.0% at 2 ppm NO₂. The increase in the thickness of the CNF film of the sensor induced a growth in ΔR/R₀ to NO₂ that is attributed to the formation of a porous film. With increased film thickness, the response improves (from 7.0% to 10.6% at 2 ppm NO₂) as does the signal-to-noise ratio (from 735:1 to 1892:1). The creation of hybrid all-carbon composites based on CNFs and multi-walled carbon nanotubes (MWCNTs) resulted in a decrease in both sensor response and signal-to-noise ratio; however, the response time and recovery degree improved. Two types of hybrid materials based on CNFs and MWCNTs were created using aerosol spraying to enhance the sensor behavior of CNFs. The obtained data confirm the dominant role of the thickness of CNF-based films and their density (in terms of distance between nearest carbon inclusions within the film) in sensor characteristics. The machine learning data used to describe the sensing behavior of two gases with opposite resistance changes when in contact with CNFs, namely NO₂ and NH₃, showed final accuracies of 92.13% on training data and 91.98% on validation data. Full article