Search Results (949)

This study explores the direct synthesis of carbon nanostructures on AISI 1018 low-carbon steel via spray pyrolysis, using α-pinene—a turpentine-derived terpene—as a sustainable carbon source. Two synthesis routes were evaluated: a catalyst-aided approach using ferrocene and a catalyst-free approach. Both methods yielded homogeneous coatings; however, the addition of ferrocene produced carbon nanotube (CNT) films (~70 μm), while the catalyst-free method resulted in carbon nanofiber (CNF) films (~50 μm). Tribological testing revealed that CNF coatings maintained a consistently low friction coefficient of ~0.12. In contrast, CNT coatings exhibited higher friction, increasing from 0.15 to 0.35 under loads of 2–5 N. SEM and Raman spectroscopy of the wear tracks suggest that CNFs retain their crystalline structure during friction, whereas CNTs become increasingly defective, leading to higher friction levels. Full article

Aramid nanofibers (ANFs) inherit the exceptional properties of the bulk counterparts, while introducing a large specific surface area and excellent processability. However, the strong inter-fibrillar interactions and tendency to agglomerate hinder their high-content incorporation into polymer matrices. Here, we report a one-pot reprotonation–compounding strategy for fabricating aramid nanofiber-reinforced poly(vinyl alcohol) (ANF–PVA) composite films, where the ANF dispersion was mixed with polymers during the protonation process to form a continuous 3D network in the ANF-PVA film. The optimized film with a loading of 20 wt% ANFs exhibited a tensile strength of 122.2 MPa and a toughness of 28.36 J m⁻³. Furthermore, the high ANF loading enabled versatile applications. A robust ANF-PVA hydrogel, prepared via salt-induced gelation, delivered 132% enhancement in tear strength and 38.2% increase in cyclic compressive strength compared with the PVA hydrogel. Moreover, inspired by the “brick-and-mortar” architecture of natural nacre, the fully organic ANF-PVA film was incorporated into carbon fiber/epoxy laminates, with a configuration of one nacre-inspired film per five prepreg plies, achieving a 36.5% improvement in impact toughness and minimal loss in flexural strength. This scalable reprotonation–compounding approach provides a general route for producing high-loading ANF-based composites, paving the way for the broader utilization in advanced materials. Full article

Chloride-induced corrosion is a major threat to excavated bronze artifacts, yet conventional alkaline desalination requires repeated solution replacement and generates secondary chemical waste. Herein, a series of BiOCl-loaded carbon nanofiber composites (CNFs@BiOCl-X) were prepared by KOH activation followed by hydrothermal growth of BiOCl, aiming to develop regenerable electrodes for chloride removal in capacitive deionization systems. Alkali activation regulated the surface roughness, oxygen-containing functional groups, hydrophilicity, and BiOCl loading of CNFs, while the three-dimensional conductive network helped immobilize BiOCl nanostructures and buffer the volume variation associated with reversible Bi/BiOCl conversion. Electrochemical analyses confirmed the pseudocapacitive chloride-storage behavior of the composites, with ion removal governed by the coupled effects of BiOCl redox activity, charge transfer, and interfacial ion transport. In a fixed-electrode membrane capacitive deionization system, CNFs@BiOCl-2 exhibited the best overall performance, delivering a salt adsorption capacity of 100.44 mg g⁻¹ at 1.4 V and retaining 93.17% of its desalination capacity after 35 cycles at 1.2 V. For flow-electrode capacitive deionization, the higher BiOCl-loading CNFs@BiOCl-5 showed superior utilization of active sites and achieved 94.75% NaCl removal from a 1000 mg L⁻¹ solution within 3 h, with an average desalination rate of 15.48 μg cm⁻² min⁻¹ and an energy consumption of 0.88 kWh kg⁻¹-NaCl. These findings demonstrate that rationally matching BiOCl loading with electrode configuration enables efficient and sustainable chloride management, offering a promising electrochemical strategy for conservation electrolytes and related desalination applications. Full article

Trade-offs between biomass productivity and metabolite accumulation constrain microalgae cultivation for high-value biomolecules due to nutrient competition and concurrent metabolic pathways. This study evaluated the independent and combined effects of static magnetic fields (SMF) and polymeric nanofibers on growth performance, biomass composition, and exopolysaccharide (EPS) profiles of Porphyridium purpureum. A process intensification strategy was applied by integrating external physical forcing and structured functional materials to enhance mass transfer and carbon utilization efficiency. Cultivations were conducted under controlled photobioreactor conditions using SMF exposure for 1 h d⁻¹ or 24 h d⁻¹, combined with polyacrylonitrile (PAN) nanofibers or monoethanolamine-functionalized nanofibers (MEA). Intermittent SMF increased maximal biomass concentration by 36% compared to the control, whereas continuous SMF, MEA nanofibers, and combined conditions reduced biomass accumulation by up to 45%. SMF promoted metabolic reallocation toward carbon-rich fractions, increasing released polysaccharides by 83% and lipid content by 38%. Nanofibers strongly enhanced pigment biosynthesis, with β-phycoerythrin reaching 41.3 mg g⁻¹, threefold higher than the control. EPS characterization showed increased purity, uronic acid content, and sulfation depending on treatment. Overall, SMF and nanofibers acted as selective intensification tools, enabling tunable modulation of growth, metabolism, and product formation. Full article

Capacitive deionization (CDI) is an environmentally advantageous desalination technology that is particularly suitable for the treatment of low- to medium-concentration saline water. Among different electrode materials, carbon materials are widely used due to their good electrical conductivity and high specific surface area, while they suffer from limited ion adsorption capacity. In this study, a cobalt/nitrogen-doped porous carbon fiber composite with Zn-induced porosity (CoNG@V@CNF), where “V” stands for “volatile pore-forming agent”, has been successfully prepared via electrospinning combined with a high-temperature carbonization process. The introduction of trace Co nanoparticles enhances the stability of porous graphene. In addition, N doping contributes to improved wettability and electronic conductivity, and the carbon fiber structure constructs a three-dimensional conductive network, providing fast channels for ion transport. Electrochemical tests show that the specific capacitance of CoNG@V@CNF reaches 252.76 F g⁻¹, demonstrating its superior charge storage capability. Furthermore, this study achieved a high salt adsorption capacity of 58.28 mg g⁻¹ and a competitive desalination rate performance of 1.94 mg g⁻¹ min⁻¹. After 40 cycles of testing, the salt adsorption capacity (SAC) remains at 56.72 mg g⁻¹, demonstrating its high stability during multiple charging and discharging processes. This work provides a new design strategy for developing high-performance CDI electrode materials. Full article

Catalytic oxidation is one of the most effective technologies for controlling atmospheric pollutants like carbon monoxide (CO), volatile organic compounds (VOCs), and diesel soot. Catalyst performance is governed by the interplay between reaction mechanisms, physicochemical properties, and catalyst architecture. This review provides a comprehensive overview of the fundamental oxidation pathways, including Langmuir–Hinshelwood, Eley–Rideal, and Mars–van Krevelen mechanisms, highlighting their relationship with oxygen mobility, oxygen vacancies, redox behavior, and metal–support interactions. The catalytic roles of noble metals and transition metal oxides are comparatively discussed, with emphasis on the contribution of lattice oxygen and defect chemistry to oxidation activity. The review also examines recent advances in structured catalysts designed to improve heat and mass transfer, catalyst accessibility, and practical reactor performance. Particular attention is given to biomorphic fibers, electrospun nanofibers, catalytic ceramic papers, conventional monoliths, and additively manufactured (3D-printed) monolithic structures as emerging platforms for environmental catalysis. Unlike previous reviews focused primarily on catalyst composition or individual oxidation reactions, this review integrates oxidation mechanisms, catalyst chemistry, and emerging structured catalyst architectures to provide a unified perspective on the design of efficient, durable, and scalable catalytic systems for environmental oxidation applications, while identifying key challenges and future research directions. Full article

Bacterial cellulose (BC) is a high-purity biopolymer with significant potential for sustainable material applications. However, its production remains limited by the metabolic behavior and compositional complexity of available carbon substrates. Simple sugars such as fructose, glucose, and sucrose support BC synthesis but differ in their metabolic pathways and associated byproduct formation, which can influence medium pH and cellulose biosynthesis. Across refined substrates, fructose generally outperforms glucose, producing the most favorable balance between productivity and structure. Reported fructose-based yields range from 1.55 to 6.29 g/L depending on the composition. In media containing hexoses, such as fructose, and three-carbon compounds, such as glycerol and pyruvate, biosynthesis proceeds via the pentose phosphate pathway. Additionally, pyruvate can be further metabolized via gluconeogenesis coupled with the tricarboxylic acid cycle, producing more BC precursors. In contrast, glucose-based yields are limited primarily by oxidation to gluconic acid, and sucrose often shows slower or lower initial production due to delayed metabolism, depending on the medium’s composition. Interestingly, structural trends showed that yield and structural quality are not always coupled. Fructose-based BC can reach around 90% to 92% crystallinity index (CrI) and is associated with lower porosity and larger nanoribbon networks, while sucrose-based BC can reach up to a 95.2% CrI despite slower initial production. Dual sugar systems further reveal differences in metabolism. Glucose-containing carbon sources are often suppressive because glucose dominates metabolism and acidification, whereas fructose-containing systems more often show synergistic behavior and support higher yields. Structural outcomes in these systems depend more on biosynthesis rates and strain-specific behavior than on carbon sources only. Additionally, low-cost substrates derived from agro-industrial residues and lignocellulosic biomass offer economically viable feedstock but introduce variability due to inhibitory compounds such as organic acids and phenolics. This review examines how sugar type and substrate complexity affect BC production and its structural properties in acetic acid bacteria, particularly the genera Acetobacter, Gluconacetobacter, and Komagataeibacter, with emphasis on the relationship between BC yield and CrI. Our analysis of the reported fermentation and characterization data in this review reveals a recurring paradox between yield and structural quality, in which substrates that promote higher BC yields do not always produce materials with superior structural properties such as crystallinity or degree of polymerization. Comparative examination of the literature revealed that inhibitory compounds such as phenolic compounds may act as structural modulators rather than simple yield suppressors. Phenolic compounds are predicted to bind to BC through non-covalent interactions facilitated by the large surface area and porous structure of BC. These interactions may influence the self-assembly of BC nanofibers. These findings indicate that fructose often offers the best balance of yield and structure. While sucrose tends to favor structural order, glucose is susceptible to yield loss from acidification, and waste-derived substrates can provide economic, high-yield, and structural properties only when their inhibitory compounds are well controlled. Full article

Phenolic resin is widely used as a binder in high-temperature industries; however, its pyrolysis generally yields isotropic glassy carbon, which strongly influences its high-temperature oxidation behavior. In this work, cupric tartrate was introduced as a catalyst precursor to investigate its effects on the thermal decomposition behavior, microstructural evolution, and oxidation behavior of the phenolic resin pyrolytic carbon. Upon heating, cupric tartrate decomposed at 250–320 °C into nanoscale Cu/Cu₂O composites, which were then converted into metallic Cu nanoparticles through reduction by gaseous products generated during the pyrolysis of phenolic resin. The in situ formed Cu nanoparticles were associated with the growth of tapered carbon nanofibers (CNFs), reaching maximum lengths of 30–50 μm at 700 °C. Based on the observed microstructural features and established literature reports, a dissolution–precipitation pathway is proposed to rationalize the formation of these CNFs. The presence of Cu-catalyzed CNFs correlates with enhanced structural ordering of the pyrolytic carbon, as reflected by reduced I_D/I_G ratios, and with an increased apparent oxidation activation energy in the selected fitting region (from 103.73 to 137.45 kJ/mol). Overall, this work demonstrates a facile strategy in which cupric tartrate serves as an effective catalyst precursor that generates Cu nanoparticles in situ; these nanoparticles then catalyze CNF growth from phenolic resin, enabling the construction of low-dimensional carbon nanostructures. Full article

With the rapid development of the pharmaceutical industry and animal husbandry, conventional wastewater treatment plants have difficulty effectively degrading the widely occurring ceftiofur sodium (CEF) in aquatic environments. To address this issue, this study successfully loaded Fe/Co-ZIF onto carbon nanofibers (CNF), thereby preparing Fe/Co-ZIF@CNF composites with well-dispersed supported materials and a stable structure. The as-prepared Fe/Co-ZIF@CNF was further applied in a persulfate-based advanced oxidation system (SR-AOPs) for CEF degradation and exhibited good catalytic performance. When the Fe/Co molar ratio was 1.25:1, the Fe/Co-ZIF_1.25 material achieved a CEF degradation efficiency, k_obs value, and TOC removal rate of 94.0%, 0.135 min⁻¹, and 43.8%, respectively. Radical quenching experiments preliminarily indicated that SO₄^•− played a dominant role in the reaction system, while •OH and ¹O₂ also made non-negligible contributions to CEF degradation. This work provides a new strategy for constructing composite catalysts based on carbon nanofiber-supported polymetallic MOFs. Full article

To develop high-performance and eco-friendly passive daytime radiative cooling (PDRC) materials, calcium carbonate (CaCO₃)/porous polylactic acid (PLA) nanofibers were fabricated via electrospinning. This fabrication utilized PLA as the matrix and 40 nm CaCO₃ nanoparticles as fillers, with ambient humidity controlled above 85%RH during electrospinning. The resulting nanofibers possessed numerous CaCO₃/PLA interfaces and porous surface structures. Experimental results demonstrated that the CaCO₃/porous PLA nanofibers achieved a solar reflectivity of ~92.3%, significantly exceeding that of PLA (~72.1%), CaCO₃/PLA (~86.0%), and porous PLA (~79.6%) nanofibers. During outdoor testing, CaCO₃/porous PLA nanofibers exhibited optimal PDRC performance with a temperature reduction of ~10.3 °C, representing a 6.1 °C improvement compared to PLA nanofibers. This enhancement is attributed to synergistic light-scattering sites generated by surface porosity and CaCO₃/PLA interfaces, which collectively strengthen solar spectrum scattering. Furthermore, significant morphological degradation was observed after 80-day soil burial, confirming biodegradability. This study proposes a facile strategy for developing high-performance eco-friendly PDRC materials. Full article

Impaired wound healing arises from interacting biological and material challenges, including persistent infection, biofilm formation, oxidative stress, unresolved inflammation, impaired angiogenesis, defective epithelialization, hemorrhage, and insufficient real-time assessment of wound status. Quantum dot (QD) and nanodot nanosystems have emerged as a versatile class of bioactive wound interfaces capable of addressing these barriers through functions that extend beyond passive coverage. This review synthesizes the design rationale, material composition, validation strategies, functional outcomes, mechanistic interpretation, and translational relevance of QD-enabled platforms for precision wound repair. Across the reviewed literature, carbon dots, graphene QDs, black phosphorus QDs, metal and metal oxide QDs, transition-metal nanodots, and hybrid nanocomposites were incorporated into hydrogels, films, sponges, nanofibers, microneedles, scaffolds, membranes, sprays, and injectable matrices. Their major precision-enabling attributes include localized antimicrobial and antibiofilm activity, redox-adaptive behavior, photothermal and photodynamic activation, inflammatory and macrophage modulation, hemostasis, controlled therapeutic delivery, angiogenic and epithelial support, and fluorescence-based monitoring. The strongest conceptual advance is the transition from static wound dressings toward adaptive biointerfaces that can sense, respond to, or compensate for local wound state abnormalities. Nevertheless, the field remains largely preclinical, with important gaps in long-term safety, standardized characterization, clinically predictive models, manufacturing reproducibility, regulatory alignment, and human validation. Future progress will depend on rationally simplified multifunctional platforms, rigorous comparative testing, wound state-specific evaluation frameworks, and translation-oriented safety and usability studies. QD nanosystems therefore represent a promising foundation for precision wound repair, provided that their multifunctionality is matched by equally rigorous evidence of safety, reproducibility, and clinical relevance. Full article

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

Numerous surface modification strategies, particularly nanoengineering approaches, have been explored to tailor the physicochemical and topographical properties of titanium surfaces in order to enhance osteogenic responses at the implant interface. In this study, we propose an alkaline ozonation strategy as a novel approach to generate nanostructured TiO₂ layers on Ti-6Al-4V alloy surfaces. Titanium discs were treated in a 6 M KOH solution under continuous bubbling of ozone, allowing the formation of reactive oxygen species (ROS) responsible for oxidative surface restructuring. Scanning electron microscopy (SEM) revealed the formation of a homogeneous three-dimensional TiO₂ nanonetwork composed of intertwined nanofibers. X-ray photoelectron spectroscopy (XPS) confirmed the oxidative reconstruction of the Ti alloy surface. The fraction of Ti⁴⁺ species characteristic of TiO₂ increased markedly from 44.2 at% to 92.2 at%, accompanied by a strong reduction in Ti⁰ (from 40.2 at% to 5.8 at%) and Ti³⁺ (from 15.7 at% to 2.1 at%). Concomitantly, lattice oxygen associated with Ti–O–Ti bonding increased from 48 at% to 78 at% as deduced from the O 1s signal, while the surface carbon content decreased from 48 at% to 18 at%. The modification induced a pronounced increase in surface hydrophilicity, with the water contact angle decreasing from 85° to 32° and the surface free energy increasing from 40.8 mJ/m² to 69.8 mJ/m². In vitro studies demonstrated good cytocompatibility and enhanced osteogenic differentiation of human mesenchymal stem cells, with twice as much alkaline phosphatase activity after 14 days and mineralization of the extracellular matrix after 28 days than those on TCPS, and also significantly higher than those on the nonmodified Ti alloy control. These findings indicate that the generated three-dimensional TiO₂ nanonetwork acts as a surface-confined nanoscaffold providing nanoscale cues that promote osteogenic cell responses on titanium implant surfaces. 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

To improve the durability of terahertz (THz) electromagnetic shielding materials in atomic oxygen environments relevant to low Earth orbit (LEO), two MXene/para-aramid nanofiber (ANF) composite architectures were designed, including a uniformly blended structure and a sandwich configuration. Ti₃C₂T_x MXene was used as the conductive phase, while ANF served as a protective matrix. Oxygen plasma treatment was employed to simulate atomic oxygen exposure. The results show that the plasma resistance of blended films strongly depends on MXene content. Increasing the MXene fraction enhances conductive network redundancy and reduces conductivity degradation. In contrast, the sandwich-structured film exhibits superior structural stability. The outer ANF layers effectively limit direct plasma–MXene interaction and undergo surface carbonization during plasma exposure, forming an additional diffusion barrier. As a result, the sandwich film maintains stable THz shielding performance, with the average shielding effectiveness increasing from 42.6 dB to 44.9 dB after plasma treatment. These results indicate that structural regulation of the internal conductive network, which limits plasma penetration, is essential for maintaining stable MXene-based THz shielding performance under oxidative plasma conditions. Full article