Functionalized Carbon Nanofibers Research Articles

Electrochemical Detection of Ornidazole Using a WS2 /CNFs Sensor

In recent decades, pharmaceutical compounds, notably antibiotics, have played a significant role in preventing infections and illnesses that affect both animals and humans. However, the utilization of antibiotics in the pharmaceutical industry, farming and other applications has led to environmental concerns 1. Nitroimidazole, an oral drug, is commonly used as an antibacterial agent. An example of a drug in nitroimidazole family is ornidazole (ORZ, (1-(3-chloro-2-hydroxy) propyl-2-methyl- 5-nitroimidazole)), and it is used in treating and preventing various infections, including genitourinary tract, intestinal and protozoal infections. Ornidazole has a heterocyclic structure comprising of an imidazole-based nucleus with a nitro group (NO2)1 and have become a well-established group of antiprotozoan and antibacterial agents. Beyond immediate therapeutic benefits, ornidazole could persist in the environment, posing long-term risks such as potential mutagenic and carcinogenic effects. Moreover, excessive antibiotics such as antibiotics such as ORZ in the environment can lead to the development of antibiotic-resistant pathogens. The widespread use of antibiotics in medical treatment and agriculture contributes to water contamination as these substances find their way into water bodies through various pathways. There is escalating concern over pharmaceutical contaminants therefore highlighting the importance of monitoring and regulating antibiotic levels in the environment. This requires significant research and electrochemical methods portray possibilities for drug detection due to their advantages of high sensitivity, low cost, simplicity and selectivity.Recent developments have brought to the spotlight, two dimensional materials as promising candidates for environmental sensing, due to their unique characteristics and wide-ranging applications. In particular, Transition-metal dichalcogenides (TMDs), comprising of MX2 , with M a transition metal atom e.g. Mo, W etc. and X, a chalcogen atom S, Se or Te 2, have garnered attention for their exceptional features. These materials consist of M atoms closely sandwiched between two layers of X atoms, linked by strong in-plane covalent bonds, and further bonded by weak van der Waals forces between the layers. Among the TMDs, tungsten disulfide (WS2) exhibits exceptional properties, including high electronic conductivity, good chemical stability, large capacitance and surface area. Those inherent properties of WS2, make it a suitable material for various applications, especially in environmental sensing 3.This study explores the detection of ornidazole using a composite material of WS2 with functionalized carbon nanofibers (CNFs). Carbon nanofibers (CNFs) are featured for their equally outstanding electrical and mechanical properties that make them promising candidates for sensor applications. CNFs also provide a unique platform for developing sensitive and selective sensors. Their versatility allows for functionalization, enhancing chemical properties and enabling tailored interactions with target analytes. The study emphasizes how CNFs, with their notable properties, complement WS2 in the creation of innovative sensor structures to create composites with improved sensing capabilities for drug compounds. In this study, the WS2/CNF nanocomposite was synthesized using hydrothermal synthesis and subsequently dispersed in ethanol and water, and then drop casted on a glassy carbon electrode. Prior to synthesis, the CNFs were functionalized using a low cost, environmental friendly method, thus enhancing their chemical properties. Herein, the resulting WS2/CNF composite demonstrates its efficacy in detecting ornidazole, and shows excellent potential for the development of electrochemical sensors. Overall, the work here aims to highlight the ongoing progress of electrochemical sensor technology, emphasizing its crucial role in addressing the growing challenges associated with drug contamination in the environment.References(1) Ettadili, F. E.; Azriouil, M.; Matrouf, M.; Tahiri Alaoui, O.; Laghrib, F.; Farahi, A.; Bakasse, M.; Saqrane, S.; Lahrich, S.; El Mhammedi, M. A. Materials Framework Based Bio/Sensors for the Detection of Ornidazole and Metronidazole Antibiotics in Environment and Foodstuffs. Inorganic Chemistry Communications. 2022. https://doi.org/10.1016/j.inoche.2022.109416.(2) Manzeli, S.; Ovchinnikov, D.; Pasquier, D.; Yazyev, O. V.; Kis, A. 2D Transition Metal Dichalcogenides. Nature Reviews Materials. 2017. https://doi.org/10.1038/natrevmats.2017.33.(3) Santos, B. G.; Gonçalves, J. M.; Rocha, D. P.; Higino, G. S.; Yadav, T. P.; Pedrotti, J. J.; Ajayan, P. M.; Angnes, L. Electrochemical Sensor for Isoniazid Detection by Using a WS2/CNTs Nanocomposite. Sensors and Actuators Reports 2022, 4. https://doi.org/10.1016/j.snr.2021.100073.

A WS2/CNF Nanocomposite for Electrochemical Sensing Applications

Successful environmental monitoring is crucial to safeguarding humans and the natural world. The presence of antibiotics in aquatic environments has become a pressing global concern, posing potential risks to both ecosystems and public health. Extensive use of antibiotics in medical treatment and agriculture has led to their release into water bodies through various pathways, contributing to water contamination. Detecting and monitoring antibiotic residues in water is crucial to understanding the extent of contamination and mitigating its adverse effects. Furthermore, the escalating concern over pharmaceutical contaminants in the environment has prompted significant research efforts towards the development of advanced sensing technologies.Recently, 2D materials have emerged as promising candidates for environmental sensing, due to their unique properties and potential applications. Transition-metal dichalcogenides or TMDs, are two-dimensional (2D) materials comprising of MX2, with M a transition metal atom e.g. Mo, W etc. and X, a chalcogen atom S, Se or Te1. The M atoms are sandwiched between two layers of X atoms with robust in-plane covalent bonds, and weak van der Waals forces between the planes. Among the TMDs, tungsten disulfide (WS2) exhibits outstanding properties, such as high electronic conductivity, large capacitance, high surface area, and chemical stability. This study explores the promising characteristics of WS2 and its synergistic potential of combining it with carbon materials to develop hybrid structures2. Carbon nanofibers (CNFs) exhibit exceptional properties that make them promising candidates for sensor applications. With their large surface area, and excellent electrical conductivity, CNFs offer a unique platform for the development of sensitive and selective sensors. In addition, CNFs versatility allows for functionalization, enhancing their chemical properties and facilitating tailored interactions with target analytes. Furthermore, owing to these notable properties, carbon nanofibers complement WS2 in the development of innovative sensor structures. Here, WS2 was combined with functionalized carbon nanofibers, to create a composite structure that was employed to detect ornidazole (ORZ), an antibiotic drug.Ornidazole, belonging to the nitroimidazole class of antibiotics, is commonly employed in the treatment of various genitourinary tract and protozoal infections3. Beyond the immediate therapeutic benefits, antibiotics such as ornidazole can persist in the environment, posing long-term risks. Moreover, excess ORZ in the environment has potential mutagenic & carcinogenic effects, and can lead to the development of antibiotic resistant pathogens. In this study, the WS2 /CNF nanocomposite was synthesized using hydrothermal synthesis and subsequently dispersed in ethanol and water, and then drop casted on a glassy carbon electrode. Prior to synthesis, the CNFs were functionalized using a low cost, environmental friendly method, thus enhancing their chemical properties. Herein, the resulting WS2/CNF composite demonstrates its efficacy in detecting ornidazole (ORZ), and shows excellent potential for the development of electrochemical sensors. Overall, the work here aims to underscore the continuous development of electrochemical sensor technology, emphasizing its pivotal role in addressing the growing challenges associated with drug contamination in the environment.(1) Manzeli, S.; Ovchinnikov, D.; Pasquier, D.; Yazyev, O. V.; Kis, A. 2D Transition Metal Dichalcogenides. Nature Reviews Materials. 2017. https://doi.org/10.1038/natrevmats.2017.33.(2) Santos, B. G.; Gonçalves, J. M.; Rocha, D. P.; Higino, G. S.; Yadav, T. P.; Pedrotti, J. J.; Ajayan, P. M.; Angnes, L. Electrochemical Sensor for Isoniazid Detection by Using a WS2/CNTs Nanocomposite. Sensors and Actuators Reports 2022, 4. https://doi.org/10.1016/j.snr.2021.100073.(3) Koventhan, C.; Vinothkumar, V.; Chen, S. M. Development of an Electrochemical Sensor Based on a Cobalt Oxide/Tin Oxide Composite for Determination of Antibiotic Drug Ornidazole. New Journal of Chemistry 2021, 45 (28). https://doi.org/10.1039/d1nj01345a

Finely Tunable Carbon Nanofiber Catalysts for the Efficient Production of HMF in Biphasic MIBK/H2O Systems.

This work proposes catalytic systems for fructose dehydration to 5-hydroxymethylfurfural using a series of functionalized carbon nanofibers. The catalysts were synthesized via finely selected covalent grafting in order to include a variety of functionalities like pure Bronsted acid, tandem Brønsted/Lewis acid, and tandem Lewis acid/Lewis base catalysts. After the characterization and evaluation of acidity strength and the amount of acid centers, the catalyst series was screened and related to the product distribution. The best-performing catalyst was also used to optimize the reaction parameters in order to achieve 5-hydroxymethylfurfural yields rounding at 60% without significant humin formation.

Dithizone functionalized carbon nanofibers as novel nanomaterial for microextraction and determination of mercury in non-alcoholic beverages

In this work, a new nanomaterial obtained by surface functionalization of carbon nanofibers with dithizone (CNF@DTZ) was implemented as adsorbent in the dispersive micro-solid phase extraction technique. Preconcentration and determination of Hg in non-alcoholic beverage samples including fruit juices and drinking water were performed with the proposed method. Important parameters of the extraction and back-extraction steps were optimized. Using 3 mg CNF@DTZ only, an extraction efficiency of 98.0 % was achieved for 30 mL of sample. Quantitative back-extraction was achieved with 600 µL of 12 mol/L HCl. A sensitivity enhancement factor of 50 was obtained. The calibration curve was linear in the range from 0.23 to 4.0 µg/L, the LOD was 0.07 µg/L and the RSD% was 3.5 % (2 µg/L Hg, n = 10). This methodology was successfully applied on spiked samples with recoveries from 96.0 to 100 %. This work reports the first application of CNF@DTZ in the dispersive micro-solid phase extraction technique for trace Hg determination in non-alcoholic beverages.

Application of functionalized carbon nanofibers as a modifying additive to motor oil

Due to the widespread of lubricants, improving their tribological characteristics remains an important practical task. Among the promising modifying additives, carbon nanomaterials attract special attention. Such materials are found to improve the antifriction characteristics of lubricants and oils. In the present research, carbon nanofibers were synthesized via catalytic pyrolysis of a mixture of light hydrocarbons (C2-C4) over the NiCu catalyst. In order to form functional groups on the surface of carbon nanofibers, they were treated with diluted acids HCl, HNO3, and H2SO4 as well as with concentrated HNO3. The functionalized samples were comprehensively characterized by a set of physicochemical methods including atomic absorption spectroscopy, scanning and transmission electron microscopies, low-temperature nitrogen adsorption, X-ray photoelectron spectroscopy, temperature-programmed desorption/oxidation, and Raman spectroscopy. As defined, the surface oxygen concentration in the samples varies from 3.5 to 16.3 at.%. It was shown that the addition of modified carbon nanofibers to a motor oil leads to an improvement in its tribological characteristics. In particular, the most effective additive was the sample treated with diluted HNO3. The motor oil with this modifying additive exhibited the heating temperature decreased by 10 °C and the contact spot area on the stationary body decreased by 20 %.

Modification of Zinc Tungstate with Functionalized Carbon Nanofibers for Electrochemical Detection of 3-Nitro-L-Tyrosine in Tap Water and Bovine Serum Albumin

Abstract Precise revealing and early detection of 3-Nitro-L-Tyrosine (3-NLT), a biomarker of oxidative stress in biological media is critical for the early treatment of cancer tumorigenic cells and immunologic disorders. In this study, zinc tungstate (ZnWO4) was incorporated with functionalized carbon nanofibers (f-CNF) to form a ZnWO4/f-CNF composite. The composite improves detection of 3-NLT by increasing the electrical conductivity, electrocatalytic activity, and rapid electron transfer kinetics. Various physical characterization techniques were employed to confirm the ZnWO4/f-CNF composite. Electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry were utilized to detect 3-NLT after modifying ZnWO4/f-CNF on glassy carbon electrode (GCE). The ZnWO4/f-CNF/GCE achieved an elevated electrochemically active surface area (0.08 cm2), a linear range of 1.0-117.0 µM, and a low detection limit of 0.07 µM. Finally, the ZnWO4/f-CNF/GCE was tested with bovine serum albumin and tap water in the real sample investigation.

Enhanced electrochemical detection of tartrazine in beverages and liquid soap via nickel phosphide-adorned functionalized carbon nanofibers

BackgroundTartrazine (TAT) is a widely used food colorant dye, offering an orange-yellow hue in various products such as foods, cosmetics, and pharmaceuticals. Despite its popularity, TAT is banned in several countries due to its potential health risks, including respiratory issues, migraines, and skin allergies. Moreover, TAT is linked with adverse effects on human physiology, including mutagenicity, biliary cirrhosis, changes in liver and kidney functions, and neurodegeneration at varying doses. Consequently, the detection of this food additive is crucial for safeguarding human health and protecting aquatic organisms. MethodsIn this study, a novel sensor was developed for the detection of TAT, utilizing a composite material made from nickel phosphide decorated with functionalized carbon nanofiber (Ni2P@f-CNF). The Ni2P@f-CNF was synthesized and characterized through several techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, field emission-scanning electron microscopy, and elemental mapping. The composite was then integrated with a glassy carbon electrode to create a sensor. The sensor's performance was evaluated in terms of detection limit, linear range, selectivity, sensitivity, reproducibility, repeatability, and long-term stability. Main FindingsThe developed Ni2P@f-CNF composite sensor displayed a lower detection limit of 0.011 µM and a broad linear range from 0.01 to 1875 µM. Its selectivity and sensitivity were exceptional, primarily due to the catalytic activity of the Ni2P@f-CNF composite towards TAT. The sensor also demonstrated excellent reproducibility, repeatability, and notable long-term stability. Importantly, when applied in real-world scenarios, the sensor successfully detected TAT in soft drink and liquid soap samples, yielding high recovery rates between 97.45 % to 99.37 % and 98.26 % to 99.01 %, respectively, underscoring its potential applicability in practical settings.

A disposable tartrazine sensor fabricated with a synchronously activated nanocomposite comprising gadolinium molybdate nanoflowers anchored on functionalized carbon nanofibers

Preparation and fabrication of a Gd2MoO6/f-CNF nanocomposite for the electro-oxidation of TRZ in food samples.

Design and fabrication of La-based perovskites incorporated with functionalized carbon nanofibers for the electrochemical detection of roxarsone in water and food samples.

The pentavalent arsenic compound roxarsone (RSN) is used as a feed additive in poultry for rapid growth, eventually ending up in poultry litter. Poultry litter contains chicken manure, which plays a vital role as an affordable fertilizer by providing rich nutrients to agricultural land. Consequently, the extensive use of poultry droppings serves as a conduit for the spread of toxic forms of arsenic in the soil and surface water. RSN can be easily oxidized to release highly carcinogenic As(III) and As(IV) species. Thus, investigations were conducted for the sensitive detection of RSN electrochemically by developing a sensor material based on lanthanum manganese oxide (LMO) and functionalized carbon nanofibers (f-CNFs). The successfully synthesised LMO/f-CNF composite was confirmed by chemical, compositional, and morphological studies. The electrochemical activity of the prepared composite material was examined using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The obtained results confirmed that LMO/f-CNF showed enhanced electrocatalytic activity and improved current response with a good linear range (0.01-0.78 μM and 2.08-497 μM, respectively), exhibiting a low limit of detection (LOD) of 0.004 μM with a high sensitivity of 13.24 μA μM-1 cm-2 towards the detection of RSN. The noteworthy features of LMO/f-CNF composite with its superior electrochemical performance enabled reliable reproducibility, exceptional stability and reliable practical application in the analysis of tap water and food sample, affording a recovery range of 86.1-98.87%.

Neodymium niobate nanospheres on functionalized carbon nanofibers: a nanoengineering approach for highly sensitive vanillin detection.

Vanillin (VAN), the primary aroma compound in vanilla, contributes significantly to sensory delight; however, its unrestrained presence poses notable health risks. In response to the demanding concern regarding food safety, researchers have directed their efforts towards the detection of VAN, seeking sustainable strategies for contamination prevention. A groundbreaking solution has emerged in the form of a novel sensing platform, whose core lies on a finely tuned electrode, crafted through the incorporation of nano-sized NdNbO4 spheres onto carbon nanofibers (CNFs). This incorporation serves to augment the capabilities of a glassy carbon electrode (GCE), transforming it into a highly sensitive detector primed for vanillin detection. The NdNbO4/f-CNF nanocomposite embodies a paradigm of synergistic collaboration, wherein the nonlinear cumulative effects of synergism and quantum confinement impart exceptional performance characteristics. Notably, the sensor achieves a low detection limit of 6.3 nmol L-1, indicative of its remarkable sensitivity of 2.3 μA μ(mol L-1)-1 cm-2 and precision of 1.519 and 4.72%. Moreover, the sensor boasts a wide linear range spanning from 0.001 to 63.101 μmol L-1. These attributes, coupled with its discerning selectivity and robust stability, underscore its efficacy as a versatile tool for vanillin detection. Indeed, its successful deployment in monitoring food samples underscores its applicability across diverse culinary contexts, further cementing its status as a pivotal asset in safeguarding food quality and consumer well-being.

Environmentally Benign Fast-Degrading Conductive Composites.

An environmentally benign conductive composite that rapidly degrades in the presence of warm water via enzyme-mediated hydrolysis is described. This represents the first time that hydrolytic enzymes have been immobilized onto eco-friendly conductive carbon sources with the express purpose of degrading the encapsulating biodegradable plastic. Amano Lipase (AL)-functionalized carbon nanofibers (CNF) were compounded with polycaprolactone (PCL) to produce the composite film CNFAL-PCL (thickness ∼ 600 μm; CNFAL = 20.0 wt %). To serve as controls, films of the same thickness were also produced, including CNF-AL5-PCL (CNF mixed with AL and PCL; CNF = 19.2 wt % and AL = 5.00 wt %), CNF-PCL (CNF = 19.2 wt %), ALx-PCL (AL = x = 1.00 or 5.00 wt %), and PCL. The electrical performance of the CNF-containing composites was measured, and conductivities of 14.0 ± 2, 22.0 ± 5, and 31.0 ± 6 S/m were observed for CNFAL-PCL, CNF-AL5-PCL, and CNF-PCL, respectively. CNFAL-PCL and control films were degraded in phosphate buffer (2.00 mg/mL film/buffer) at 50 °C, and their average percent weight loss (Wtavg%) was recorded over time. After 3 h CNFAL-PCL degraded to a Wtavg% of 90.0% and had completely degraded after 8 h. This was considerably faster than CNF-AL5-PCL, which achieved a total Wtavg% of 34.0% after 16 days, and CNF-PCL, which was with a Wtavg% of 7.00% after 16 days. Scanning electron microscopy experiments (SEM) found that CNFAL-PCL has more open pores on its surface and that it fractures faster during degradation experiments which exposes the interior enzyme to water. An electrode made from CNFAL-PCL was fabricated and attached to an AL5-PCL support to form a fast-degrading thermal sensor. The resistance was measured over five cycles where the temperature was varied between 15.0-50.0 °C. The sensor was then degraded fully in buffer at 50 °C over a 48 h period.

Palladium-Containing Catalysts Based on Functionalized Carbon Nanofibers for the Dehydrogenation of Methylcyclohexane

Palladium-Containing Catalysts Based on Functionalized Carbon Nanofibers for the Dehydrogenation of Methylcyclohexane

Ultrasensitive detection and photocatalytic degradation of polyketide drug tetracycline in environment and food samples using dual-functional Ag doped zinc ferrite embedded functionalized carbon nanofibers

The efficient degradation and accurate quantification of tetracycline in environment and food samples is pivotal for ensuring public health and safety by monitoring potential contamination and maintaining regulatory standards. Hence, in this study, photocatalytic degradation of tetracycline and its electrochemical detection in environment and food samples based on dual-functional silver-doped zinc ferrite nanoparticles embedded chitosan-functionalized carbon nanofibers fabricated on a screen-printed carbon electrode (AgZFO/CHIT-CNF/SPCE) is presented. A hydrothermal method was used in the synthesis of Ag-doped ZFO, and chitosan was functionalized on the CNF surface using a swift and cost-effective chemical modification process of carboxyl groups. Various techniques, such as XRD, HRTEM, elemental mapping, EIS, XPS, FTIR, VSM, BET, UV–Vis DRS, and Raman spectroscopy were used to analyze the characteristics of the prepared nanocomposite. Cyclic voltammetry and differential pulse voltammetry were used to evaluate the surface-controlled electrocatalytic properties of AgZFO/CHIT-CNF towards tetracycline. Electrochemical tests revealed that the proposed electrode exhibited excellent sensitivity for detecting tetracycline. The fabricated electrode had a low detection limit of 1 nM and a wide linear range (0.2–53.2 μM). The sensor also demonstrated exceptional selectivity, stability, and reusability. The practical feasibility evaluated with real samples, including chicken feed, shrimp, milk, soil, and wastewater, resulted in high recovery values.

Palladium-Containing Catalysts Based on Functionalized CNFs for the Dehydrogenation of Methylcyclohexane

The activity of palladium-containing catalysts based on functionalized carbon nanofibers prepared by an incipient wetness impregnation method in the dehydrogenation reaction of methylcyclohexane was investigated. Methylcyclohexane is considered as one of the most promising liquid hydrogen carriers. The dependence of the catalytic characteristics of the samples on the functionalization conditions of carbon nanofibers has been studied. By temperature-programmed desorption, it was shown that an increase in the treatment time of carbon nanofibers in concentrated nitric acid from 1 to 3 h increases the number of hydroxyl groups on their surface, and treatment for 6 h contributes to a rise in the concentration of carboxyl groups and their derivatives (esters and anhydrides). Additional calcination of the functionalized nanofibers in an inert atmosphere at 530°C yielded a sample containing predominantly hydroxyl groups. The presence of hydroxyl groups on the surface of the carbon material has a positive effect on the performance of the catalysts, while the presence of carboxyl groups leads to a decrease in the yield of toluene. It is assumed that the observed differences in catalyst activity are due to differences in dispersion and localization of palladium particles.

BiFeO3/g-C3N4/f-CNF ternary nanocomposite as an efficient photocatalyst for methylene blue dye degradation under solar light irradiation

The development of Perovskite oxide photocatalysts with superior dye degradation efficiency under solar light irradiation has gained attention in recent years, owing to their extraordinary flexibility, chemical composition, and tunability. Herein, we report the facile synthesis of a novel ternary composite composed of BiFeO3 (BFO) perovskite, g-C3N4, and functionalized carbon nanofibers (f-CNF), referred to as BFO/g-C3N4/f-CNF using a simple solution method as a photocatalyst to accelerate the degradation of methylene blue dye. Detailed structural and microstructural features confirm the formation of a ternary composite composed of BFO nanoparticles and f-CNFs mounted on g-C3N4 nanosheets. The photocatalytic activity of the sample for the degradation of methylene blue dye was studied in solar light using UV–visible spectroscopy. The BFO/g-C3N4/f-CNF ternary composite displays excellent photocatalytic activity with a degradation rate of 87 % after illumination for 120 min under solar light than BFO, g-C3N4, and binary composites BFO/g-C3N4 and BFO/f-CNF. The highest rate constant (k = 0.01675 min−1) for BFO/g-C3N4/f-CNF further confirms improved photocatalytic efficiency. The red shift in the UV–visible absorption spectrum of BFO/g-C3N4/f-CNF indicates a reduced band gap (1.9 eV) compared to that of pure BFO (2.28 eV) and g-C3N4 ( 2.72 eV). A decrease in the photoluminescence intensity of the ternary composite compared to that of BFO indicates the inhibition of photoexcited electron recombination which results in the availability of more charge carriers for the photocatalytic process. The enhanced efficiency of BFO/g-C3N4/f-CNF can be explained by the synergistic effect between BFO and g-C3N4 and the incorporation of f-CNF further promotes the migration rate of electrons from BFO to g-C3N4.

Flexible, Stretchable, and Thin Films Based on Functionalized Carbon Nanofiber/Graphene Nanostructures for Electromagnetic Interference Shielding

Flexible electromagnetic shielding materials (ESMs) are becoming progressively important to flexible and conformal electronic devices operating in civil, aerospace, and military industries. There is a legitimate need to fabricate flexible, thin, featherweight, and stretchable materials with higher electromagnetic interference shielding effectiveness (EMI SE) that can handle harsh environments. Graphene nanoplatelets (GNPs) are synthesized by microwave-supported exfoliation of graphite proceeded by water-bath sonication, whereas functionalized carbon nanofibers (FCNFs) are synthesized via acid functionalization using HNO3. The effects of conventional CNF, FCNF, and GNP are observed by embedding in the polyurethane (PU) matrix to obtain flexible, highly stretchable (>400%), lightweight, and thin (300 μm) nanocomposites for enhanced EMI shielding performance. The GFCNF/PU nanocomposite showed uniform distribution and excellent microwave properties at low weight%. An improvement in the total EMI SE (SET) value is noticed by adding GNP (2, 4, and 6 wt %) in FCNF4, and a maximum SET value of 60.55 dB is obtained for FCNF/GNP (4/6 wt %). A negligible change in the value of EMI SE is observed after 500 mechanical bending cycles and bath-sonicating the nanocomposites in distilled water, confirming the efficiency of operating in the complex environmental condition. Further, the value of SET is measured by placing the nanocomposites at different bending radii inside the waveguide to verify the practical applicability of fabricated nanocomposites in conformal devices. EMI shielding is also calculated for nanocomposites through simulation in the CST microwave studio tool (in the X-band), further extending the analysis for broadband frequency (1–18 GHz).

Zinc molybdate/functionalized carbon nanofiber composites modified electrodes for high-performance amperometric detection of hazardous drug Sulfadiazine

Pharmaceuticals are generally designed to be nondegradable or slowly degradable to prevent chemical degradation as it is employed as therapeutics for human or animal. This results in a widespread risk when they enter, accumulate or persist in the environment. Pharmaceutical pollution is emerging as wide-reaching concern due to its ostensible consequences, by dissemination in the environment. This demands for inventing novel analytical routes to monitor and mitigate pharmaceutical pollutants. Therefore, this paper presents synthesis of Zinc molybdate nano particles embedded on functionalized carbon nanofibers to fabricate glassy carbon electrode towards sensitive detection of Sulfadiazine (SDZ). The synergistic effect produced in the composite had enabled it with improved charge transfer kinetics and benefited with more active surface area. The proposed ZnMoO4/f-CNF sensor shows significant static characteristics such as wide linear response ranges (0.125 to1575.2 μM), low detection limit (0.0006 μM) and selectivity, and increased stability. Also, its practicability was analyzed by SDZ detection in real samples.

Selective hydrodeoxygenation of levulinic acid to γ-valerolactone over Ru supported on functionalized carbon nanofibers

In this work, carbon nanofibers (CNFs) have been successfully functionalized by using different approaches and finally used for the preparation of Ru based catalysts.

Rational design of Nd2O3 decorated functionalized carbon nanofiber composite for selective electrochemical detection of carbendazim fungicides in vegetables, water, and soil samples

Abuse of carbendazim (CBZ) leaves excessive pesticide residues on agricultural products, which endangers human health because of the residues' high concentrations. Hence, a composite consisting of functionalized carbon nanofibers (f-CNF) with neodymium oxide (Nd2O3) was fabricated to monitor CBZ at trace levels. The Nd2O3/f-CNF composite-modified electrode displays higher electro-oxidation ability towards CBZ than Nd2O3 and f-CNF-modified electrodes. The combined unique properties of Nd2O3 and f-CNF result in a substantial specific surface area, superior structural stability, and excellent electrocatalytic activity of the composite yielding enhanced sensitivity to detecting CBZ with a detection limit of 4.3 nM. Also, the fabricated sensor electrode can detect CBZ in the linear concentration range of up to 243.0 μM with high selectivity, appropriate reproducibility, and stability. A demonstration of the sensing capability of CBZ in vegetables, water, and soil samples was reported paving the way for its use in practical applications.

Lithium-enhanced functionalized carbon nanofibers as a mixed electronic/ionic conductor for sulfide all solid-state batteries

Despite the recent advancement of sulfide all-solid-state lithium batteries, the choice of their respective components yet requires further comprehensive investigations into their functionality and compatibility. While the development of cathode materials and sulfide electrolytes appears to be greatly advanced, there seems a lack of attention on carbon conductive additives. As sulfide electrolytes are unstable with conventional carbon conductive additives, it is necessary to develop conductive additives with a satisfactory electronic conductivity and good chemical/electrochemical stability with sulfide electrolytes. This study proposes a new mixed conductor based on carbon nanofiber (CNF), namely lithium-enhanced functionalized carbon nanofiber (LF-CNF), exhibiting a greatly enhanced Li-ion conductivity with a little compensation of their electronic conductivity. By utilizing LF-CNF, a discharge capacity of ca. 198 mAh g−1 at 0.05C and ca. 148mAh g−1 after 50 cycles at 0.1C were achieved from the cathode composite of LiNi0.8Co0.1Mn0.1O2, argyrodite solid electrolyte and LF-CNF (70:30:5 in mass). Furthermore, LF-CNF appears to reduce detrimental cation mixing after storage in Ar-atmosphere over one month and at high voltage cycling of 4.5 V. Our work highlights that the conductivity tuning of conductive additives offers a great performance enhancement for high-energy sulfide electrolyte based solid-state batteries.