Search Results (260)

The widespread adoption of sodium-ion batteries (SIBs) remains constrained by the inherent limitations of conventional anode materials, particularly their inadequate electronic conductivity, limited active sites, and pronounced structural degradation during cycling. To overcome these limitations, we propose a novel redox engineering approach to fabricate oxygen-vacancy-rich SnO₂ dots anchored on reduced graphene oxide (rGO), which are encapsulated within N-doped carbon nanofibers (denoted as ov-SnO₂/rGO@N-CNFs) through electrospinning and subsequent carbonization. The introduction of rich oxygen vacancies establishes additional sodium intercalation sites and enhances Na⁺ diffusion kinetics, while the conductive N-doped carbon network effectively facilitates charge transport and mitigates SnO₂ aggregation. Benefiting from the well-designed architecture, the hierarchical ov-SnO₂/rGO@N-CNFs electrode achieves remarkable reversible specific capacities of 351 mAh g⁻¹ after 100 cycles at 0.1 A g⁻¹ and 257.3 mAh g⁻¹ after 2000 cycles at 1.0 A g⁻¹ and maintains 177 mAh g⁻¹ even after 8000 cycles at 5.0 A g⁻¹, demonstrating exceptional long-term cycling stability and rate capability. This work offers a versatile design strategy for developing high-performance anode materials through synergistic interface engineering for SIBs. Full article

Background/Objectives: A nanostructured membrane of polycaprolactone (a synthetic polymer) was synthesized using an electrospinning technique aiming to enhance its hydrophilicity and rate of degradation by surface modification via aminolysis. Since polycaprolactone nanofibrous films are naturally hydrophobic and with slow degradation, which restricts their use in biological systems, amino groups were added to the fiber surface using the aminolysis technique, greatly increasing the wettability of the membranes. Methods: Polycaprolactone nanofibrous membranes were synthesized via the electrospinning technique and surface modification by aminolysis. Trypsin, pepsin, and pancreatin were conjugated onto the aminolyzed PNF surface to further strengthen biocompatibility by enhancing the hydrophilicity, porosity, and biodegradation rate. SEM, FTIR, EDX, and liquid displacement method were performed to investigate proteolytic efficiency and morphological and physical characteristics such as hydrophilicity, porosity, and degradation rates. Results: Enzyme activity tests, which showed a zone of clearance, validated the successful enzyme conjugation and stability over a wide range of pH and temperatures. Scanning electron microscopy (SEM) confirms the smooth morphology of nanofibers with diameters ranging from 150 to 950 nm. Fourier transform infrared spectroscopy (FTIR) revealed the presence of O–H, C–O, C=O, C–N, C–H, and O–H functional groups. Energy-dispersive X-ray (EDX) elemental analysis indicates the presence of carbon, oxygen, and nitrogen atoms owing to the presence of peptide and amide bonds. The liquid displacement technique and contact angle proved that Pepsin-PNFs possess notably increased porosity (88.50% ± 0.31%) and hydrophilicity (57.6° ± 2.3 (L), 57.9° ± 2.5 (R)), respectively. Pancreatin-PNFs demonstrated enhanced enzyme activity and degradation rate on day 28 (34.61%). Conclusions: These enzyme-conjugated PNFs thus show improvements in physicochemical properties, making them ideal candidates for various biomedical applications. Future studies must aim for optimization of enzyme conjugation and in vitro and in vivo performance to investigate the versatility of these scaffolds. Full article

Room-temperature vulcanizing (RTV) silicone foams are used in many industrial applications that require the material to perform over long time periods. However, mechanical properties tend to deteriorate when these foams age under a compressive load. The chemical aging is attributed to the presence of unreacted functional groups of the prepolymers, residues from acid, and catalytically active tin (II) species. Here, an optimized thermal treatment of an RTV foam that achieves completion of curing reactions and deactivation of reactive species is proposed. Foams that were thermally aged for three months under compressive load showed no signs of compression set, indicative of the effectiveness of the implemented post-curing approach. In addition, the effects of fillers (diatomaceous earth, fumed silica, and carbon nanofibers) on thermomechanical properties were investigated. Tensile strength, tear strength, and thermal conductivity increased when these fillers were added to the unfilled RTV formulation, with carbon nanofibers (CNFs) being the most effective filler. Rheological studies of RTV formulations indicated that 2.5 wt.% of CNFs is the upper limit that can be added to the RTV formulation. Full article

Introduction: Functional endoscopic sinus surgery is commonly performed to treat paranasal sinus diseases, often necessitating nasal packing to control bleeding and aid healing. However, current materials can cause discomfort or lack adequate antibacterial properties. This study aimed to develop a biodegradable, biocompatible nasal packing material by combining polyvinyl alcohol (PVA) and carbon dots (CDs), and to evaluate its antibacterial activity and tissue compatibility. Materials and Methods: Electrospun nanofiber membranes were fabricated using PVA and biomass-derived CDs. Antibacterial efficacy of nasal packing variants (PVA, PVA-chitosan [CS], PVA-CS-CDs-1 mL, and PVA-CS-CDs-2 mL) was assessed using the Kirby–Bauer disk diffusion method against Escherichia coli, Salmonella spp., and Staphylococcus aureus. The in vivo biocompatibility was evaluated via histological analysis following implantation into the nasal cavity of mice. Results: All materials demonstrated antibacterial activity, with PVA-CS-CDs-2 mL showing the largest inhibition zones. Histological examination revealed minimal epithelial damage and no inflammation, with PVA-CS-CDs-2 mL yielding the most favorable tissue response. Conclusion: The PVA-CS-CDs composite demonstrates potential as a biocompatible, antibacterial nasal packing material. Further studies are warranted to validate its long-term clinical utility. Full article

Celiac disease (CD), a human leukocyte antigen-associated disorder, is caused by gluten sensitivity and is characterized by mucosal alterations in the small intestine. Currently, its diagnosis involves the determination of serological markers. The traditional method for clinically determining these markers is the enzyme-linked immunosorbent assay. However, immunosensors offer sensitivity and facilitate the development of miniaturized and portable analytical systems. This work focuses on developing an amperometric immunosensor for the quantification of IgA antibodies against tissue transglutaminase (IgA anti-TGA) in human serum samples, providing information on a critical biomarker for CD diagnosis. The electrochemical device was designed on a polyimide substrate using a novel solid ink of wax and carbon nanofibers (CNFs). The working electrode microzone was defined by incorporating aminofunctionalized TiO₂ nanoparticles (TiO₂NPs). The interactions and morphology of CNFs/wax and TiO₂NPs/CNFs/wax electrodes were assessed through different characterization techniques. Furthermore, the device was electrochemically characterized, demonstrating that the incorporation of CNFs into the wax matrix significantly enhanced its conductivity and increased the active surface area of the electrode, while TiO₂NPs contributed to the immunoreaction area. The developed device exhibited remarkable sensitivity, selectivity, and reproducibility. These results indicate that the fabricated device is a robust and reliable tool for the precise serological diagnosis of CD. Full article

To address mass transport limitations in carbon nanofiber membrane electrodes for overall water splitting, a self-supporting nitrogen-doped hollow carbon nanofiber membrane embedded with Co/Co₂P heterojunctions (Co/Co₂P-NCNFs-H) was fabricated via continuous coaxial electrospinning. The architecture features uniform hollow channels (200–250 nm diameter, 30–50 nm wall thickness) and a high specific surface area (254 m² g⁻¹), as confirmed by SEM, TEM, and BET analysis. The Co/Co₂P heterojunction was uniformly dispersed on nitrogen-doped hollow carbon nanofibers through electrospinning, leverages interfacial electronic synergy to accelerate charge transfer and optimize the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Electrochemical tests demonstrated exceptional catalytic activity, achieving current densities of 100 mA cm⁻² at ultralow overpotentials of 405.6 mV (OER) and 247.9 mV (HER) in 1.0 M KOH—surpassing most reported transition metal catalysts for both half-reactions. Moreover, the electrode exhibited robust long-term stability, maintaining performance for nearly 20 h at 0.6 V (vs. Ag/AgCl) (OER) and over 250 h at −1.5 V (vs. Ag/AgCl) (HER), attributed to the mechanical integrity of the hollow architecture and strong metal–carbon interactions. This work demonstrates that integrating hollow nanostructures (enhanced mass transport) and heterojunction engineering (optimized electronic configurations) creates a scalable strategy for designing efficient bifunctional catalysts, offering significant promise for sustainable hydrogen production via water electrolysis. Full article

Advancements in thermoregulating textiles have been propelled by innovations in nanotechnology, composite materials, and smart fiber engineering. This article reviews recent scholarly papers on experimental passive and active thermoregulating textiles to present the latest advancements in these fabrics, their mechanisms of thermoregulation, and their feasibility for use. The review underscores that phase-change materials enhanced with graphene, boron nitride, and carbon nanofibers offer superior thermal conductivity, phase stability, and flexibility, making them ideal for wearable applications. Shape-stabilized phase-change materials and aerogel-infused fibers have shown promising results in outdoor, industrial, and emergency settings due to their durability and high insulation efficiency. Radiative cooling textiles, engineered with hierarchical nanostructures and Janus wettability, demonstrate passive temperature regulation through selective solar reflection and infrared emission, achieving substantial cooling effects without external energy input. Thermo-responsive, shape-memory materials, and moisture-sensitive polymers enable dynamic insulation and actuation. Liquid-cooling garments and thermoelectric hybrids deliver precise temperature control but face challenges in portability and power consumption. While thermoregulating textiles show promise, the main challenges include achieving scalable manufacturing, ensuring material flexibility, and integrating multiple functions without sacrificing comfort. Future research should focus on hybrid systems combining passive and active mechanisms, user-centric wearability studies, and cost-effective fabrication methods. These innovations hold significant potential for applications in extreme environments, athletic wear, military uniforms, and smart clothing, contributing to energy efficiency, health, and comfort in a warming climate. Full article

The intrinsic trade-off among sensitivity, response speed, and measurement range continues to hinder the wider adoption of flexible pressure sensors in areas such as medical diagnostics and gesture recognition. In this work, we propose a grid-structured polycaprolactone/thermoplastic-polyurethane nanofiber pressure sensor decorated with multi-walled carbon nanotubes (PCL/TPU@MWCNTs). By introducing a gradient grid membrane, the strain distribution and reconstruction of the conductive network can be modulated, thereby alleviating the conflict between sensitivity, response speed, and operating range. First, static mechanical simulations were performed to compare the mechanical responses of planar and grid membranes, confirming that the grid architecture offers superior sensitivity. Next, PCL/TPU@MWCNT nanofiber membranes were fabricated via coaxial electrospinning followed by vacuum-filtration and assembled into three-layer planar and grid piezoresistive pressure sensors. Their sensing characteristics were evaluated by simple index-finger motions and slide the mouse wheel identified. Within 0–34 kPa, the sensitivities of the planar and grid sensors reached 1.80 kPa⁻¹ and 2.24 kPa⁻¹, respectively; in the 35–75 kPa range, they were 1.03 kPa⁻¹ and 1.27 kPa⁻¹. The rise/decay times of the output signals were 10.53 ms/11.20 ms for the planar sensor and 9.17 ms/9.65 ms for the grid sensor. Both sensors successfully distinguished active index-finger bending at 0–0.5 Hz. The dynamic range of the grid sensor during the extension motion of the index finger is 105 dB and, during the scrolling mouse motion, is 55 dB, affording higher measurement stability and a broader operating window, fully meeting the requirements for high-precision hand-motion recognition. Full article

To comparatively study the effects of cold plasma activation and chemical treatment on the adsorption capacities of biomass carbon nanofiber membranes (BCNMs), microcrystalline cellulose (MCC) and chitosan (CS) were used to fabricate porous BCNMs by electrospinning and carbonization. Two modification methods, including oxygen (O₂) plasma activation and chemical treatment using nitric acid (HNO₃), sulfuric acid (H₂SO₄), hydrogen peroxide (H₂O₂), and urea, were further employed to enhance their adsorption performance. Various carbonyl group (C=O), ether bond (C-O), carboxyl group (O-C=O) and pyridinic nitrogen (N), pyrrolic N, and quaternary N functional groups were successfully introduced onto the surface of the BCNMs by the two methods. The BCNM-O₂ showed optimal formaldehyde absorption capacity (120.67 mg g⁻¹), corresponding to its highest contents of N, O-containing functional groups, and intact network structure. However, chemical treatment in strong acid or oxidative solutions destructed the microporous structures and changed the size uniformity of fibers in the BCNMs, resulting in a decline in formaldehyde adsorption capacity. A synergistically physical–chemical adsorption took place during formaldehyde adsorption by the modified biomass nanofiber membranes, due to the coexistence of suitable functional groups and porous structures in the membranes. Full article

Lithium-ion batteries (LIBs) with high power, high capacity, and support for fast charging are increasingly favored by consumers. As a commercial electrode material for power batteries, LiFePO₄ was limited from further wide application due to its low conductivity and lithium-ion diffusion rate. The development of advanced architectures integrating rational conductive networks with optimized ion transport pathways represents a critical frontier in optimizing the performance of cathode materials. In this paper, a novel self-supporting cathode material (designated as LFP@LVP-CES) was synthesized through an integrated coaxial electrospinning and controlled pyrolysis strategy. This methodology directly converts LiFePO₄, Li₃V₂(PO₄)₃, and polyacrylonitrile (PAN)) into flexible, binder-free cathodes with a hierarchical structural organization. The 3D carbon nanofiber (CNF) matrix synergistically integrates LiFePO₄ (Li/Fe/PO_x) and Li₃V₂(PO₄)₃ (Li/V/PO_x) nanoparticles, where CNFs act as a conductive scaffold to enhance electron transport, while the PO_x polyanionic frameworks stabilize Li⁺ diffusion pathways. Morphological characterizations (SEM and TEM) revealed a 3D cross-connected carbon nanofiber matrix (diameter: 250 ± 50 nm) uniformly embedded with active material particles. Electrochemical evaluations demonstrated that the LFP@LVP-CES cathode delivers an initial specific capacity of 165 mAh·g⁻¹ at 0.1 C, maintaining 80 mAh·g⁻¹ at 5 C. Notably, the material exhibited exceptional rate capability and cycling stability, demonstrating a 96% capacity recovery after high-rate cycling upon returning to 0.1 C, along with 97% capacity retention over 200 cycles at 1 C. Detailed kinetic analysis through EIS revealed significantly reduced R_ct and increased Li⁺ diffusion. This superior electrochemical performance can be attributed to the synergistic effects between the 3D conductive network architecture and dual active materials. Compared with traditional coating processes and high-temperature calcination, the preparation of controllable electrospinning and low-temperature pyrolysis to some extent avoid the introduction of harmful substances and reduce raw material consumption and carbon emissions. This original integration strategy establishes a paradigm for designing freestanding electrode architectures through 3D structural design combined with a bimodal active material, providing critical insights for next-generation energy storage systems. Full article

Carbon fibers, with high modulus of elasticity, tensile strength, and electrical conductivity, can modify the mechanical and electrical properties of cementitious composites, facilitating their practical application in smart infrastructure. This study investigates the effects of carbon nanofibers (including carbon nanotubes, a special type of carbon nanofibers) and micron carbon fibers with different aspect ratios and surface treatments on the uniaxial tensile and electrical properties of cementitious composites. The results demonstrate that appropriate carbon fiber doping markedly improves the uniaxial tensile strength of cementitious composites, with enhancement effects following a gradient trend based on a geometric scale: carbon nanotubes (CNTs) < carbon nanofibers (CNFs) < short-cut carbon fibers (CFs). Hydroxyl-functionalized multi-walled carbon nanotubes (MWCNTs) form continuous conductive networks due to surface active groups (-OH content: 5.58 wt.%), increasing the composite’s electrical conductivity by two orders of magnitude (from 3.56 × 10⁸ to 2.74 × 10⁶ Ω·cm), with conductivity enhancement becoming more pronounced at higher doping levels. Short-cut CFs also improve conductivity, with longer fibers (6 mm) exhibiting a 12.4% greater reduction in resistivity. However, exceeding the percolation threshold (0.5–1.0 vol.%) leads to limited conductivity improvement (<5%) and mechanical degradation (8.7% tensile strength reduction) due to fiber agglomeration-induced interfacial defects. This study is a vital reference for material design and lays the groundwork for self-sensing cementitious composites. Full article

The persistent threat of heavy metal ions (e.g., Pb²⁺, Hg²⁺, Cd²⁺) in aqueous environments to human health underscores an urgent need for advanced sensing platforms capable of rapid and precise pollutant monitoring. Graphitic carbon nitride (g-C₃N₄), a metal-free polymeric semiconductor, has emerged as a revolutionary material for constructing next-generation environmental sensors due to its exceptional physicochemical properties, including tunable electronic structure, high chemical/thermal stability, large surface area, and unique optical characteristics. This review systematically explores the integration of g-C₃N₄ with functional nanomaterials (e.g., metal nanoparticles, metal oxide nanomaterials, carbonaceous materials, and conduction polymer) to engineer high-performance sensing interfaces for heavy metal detection. The structure-property relationship is critically analyzed, emphasizing how morphology engineering (nanofibers, nanosheets, and mesoporous) and surface functionalization strategies enhance sensitivity and selectivity. Advanced detection mechanisms are elucidated, including electrochemical signal amplification, and photoinduced electron transfer processes enabled by g-C₃N₄’s tailored bandgap and surface active sites. Furthermore, this review addresses challenges in real-world deployment, such as scalable nanomaterial synthesis, matrix interference mitigation, and long-term reliable detection. This work provides valuable insights for advancing g-C₃N₄-based electrochemical sensing technologies toward sustainable environmental monitoring and intelligent pollution control systems. Full article

MnO is an attractive material due to its high specific capacitance and thermal and chemical activity. It can be recycled from alkaline batteries with a good yield and can be used for supercapacitor applications after enhancing its poor conductivity. In this study, Ru-MnO-Carbon nanofibers(Ru-MnO-CNFs) were prepared by the impregnation of Ru (1 wt%) into MnO recovered from used alkaline batteries, followed by their incorporation into polyacrylnitrile (PAN) nanofibers by electrospinning and carbonization. The prepared materials, Ru-MnO and Ru-MnO-CNFs, were characterized by scanning electron microscopy and Fourier infrared spectroscopy. The electrochemical characterization was performed, comparing the characteristics of Ru-MnO and Ru-MnO-CNFs samples. It was found that the capacitance of MnO recovered from used alkaline batteries could be enhanced by combining it with Ru and CNFs. The hybrid Ru-MnO/CNFs composite could be used as stable electrode material for high performance supercapacitors. Full article

Solid oxide cells (SOCs) can operate efficiently in solid oxide fuel cell (SOFC) and/or solid oxide electrolysis cell (SOEC) modes, and are one of the most promising electrochemical devices for energy conversion and storage, facilitating the integration of renewable energies with the electric grid. However, the SOC electrodes suffer performance and stability issues, especially in the case of fuel electrodes when SOCs are fueled by cheaper and more available fuels such as methane and natural gas. Typical Ni-YSZ cermet fuel electrodes suffer problems of coarsening, carbon deposition, and sulfur poisoning. Therefore, developing new electrodes using novel design strategies for SOCs is crucial. In this review work, the fuel electrode development strategies including the in situ exsolution of nanoparticles, multi-elemental nanocatalysts, and nanofiber materials have been reviewed and summarized for the design of new electrodes for SOCs. Nanofiber electrodes with in situ exsolved nanoparticles, which combine the advantages of a unique nanofiber microstructure and stable and active exsolved nanoparticles, are of great interest and significantly contribute to the development of high-performance fuel electrodes for SOCs. Full article

This study focuses on making non-precious electrocatalysts for improving the performance of Direct Alcohol Fuel Cells (DAFCs). Specifically, it examines the oxidation of ethanol and methanol. Conventional platinum-based catalysts are expensive and suffer from problems such as degradation and poisoning. To overcome these challenges, we fabricated tri-metallic catalysts composed of nickel, cobalt, and titanium dioxide (TiO₂) embedded in carbon nanofibers (CNFs). The synthesis included electrospinning and subsequent carbonization as well as optimization of parameters to achieve uniform nanofiber morphology and high surface area. Electrochemical characterization revealed that the incorporation of TiO₂ significantly improved electrocatalytic activity for ethanol and methanol oxidation, with current densities increasing from 57.8 mA/cm² to 74.2 mA/cm² for ethanol and from 38.69 mA/cm² to 60.39 mA/cm² for methanol as the TiO₂ content increased. The catalysts showed excellent stability, with the TiO₂-enriched sample (T2) showing superior performance during longer cycling tests. Chronoamperometry and electrochemical impedance spectroscopy are used to examine the stability of the catalysts and the dynamics of the charge carriers. Impedance spectroscopy indicated reduced charge transfer resistance, confirming enhanced activities. These findings suggest that the synthesized non-precious electrocatalysts can serve as effective alternatives to platinum-based materials, offering a promising pathway for the development of cost-efficient and durable fuel cells. Research highlights non-precious metal catalysts for sustainable fuel cell technologies. Full article