Carbon Nanofiber Nanocomposites Research Articles

A Ce2MgMoO6 double perovskite decorated on a functionalized carbon nanofiber nanocomposite for quantification of ciprofloxacin in milk and honey samples: Density functional theory interpretation

In this study, a novel Ce2MgMoO6/CNFs (cerium magnesium molybdite double perovskite decorated on carbon nanofibers) nanocomposite was developed for selective and ultra-sensitive detection of ciprofloxacin (CFX). Physical characterization and analytical techniques were used to explore the morphology, structure, and electrocatalytic characteristics of the Ce2MgMoO6/CNFs nanocomposite. The sensor has a wide linear range (0.005–7.71 μM and 9.75–77.71 μM), a low limit of detection (0.012 μM), high sensitivity (0.807 μA μM−1 cm−2 nM), remarkable repeatability, and an appreciable storage stability. Here, we used density functional theory to investigate CFX and oxidized CFX as well as the locations of the energy levels and electron transfer sites. Furthermore, the Ce2MgMoO6/CNFs-modified electrode was successfully tested in food samples (milk and honey), indicating an acceptable response with a recovery percentage and relative standard deviation of less than 4%, which is comparable to that of GC-MS. Finally, the developed sensor exhibited high selectivity and stability for CFX detection.

Neodymium(III) Vanadate-Decorated Functionalized Carbon Nanofiber Nanocomposite: An Electrochemical Tool for Tartrazine Monitoring

Neodymium(III) Vanadate-Decorated Functionalized Carbon Nanofiber Nanocomposite: An Electrochemical Tool for Tartrazine Monitoring

Adjustable core-sheath architecture of polyaniline-decorated hollow carbon nanofiber nanocomposites with negative permittivity for superb electromagnetic interference shielding

Adjustable core-sheath architecture of polyaniline-decorated hollow carbon nanofiber nanocomposites with negative permittivity for superb electromagnetic interference shielding

Ultrasensitive electrochemical sensor for the detection of carbamazepine based on gadolinium vanadate nanostructure decorated functionalized carbon nanofiber nanocomposite

The gadolinium vanadate nanostructure decorated functionalized carbon nanofiber (GdVO4/f-CNF) nanocomposite was prepared by the hydrothermal method, which is fabricated on a glassy carbon electrode (GCE) for the determination of carbamazepine (CBZ). The structural morphology of the hydrothermally synthesized GdVO4/f-CNF material was investigated by several spectroscopy methods such as FESEM, HRTEM, EDS-mapping, XRD, XPS, and Raman. Moreover, the electrical conductivity of our synthesized material was inspected by the electrochemical impedance spectroscopy (EIS) analysis, and the electrochemical performance towards CBZ was inspected by the cyclic voltammetry (CV) and amperometry (AMP) analysis under optimized conditions. The AMP determination of CBZ exhibits the lowest level LOD of 0.0018 μM and a good linear range of 0.01–157 μM. Additionally, our proposed sensor was used to determine the CBZ in the pharmaceutical and, human urine samples which have exposed the acceptable recoveries.

Synchronously activated strontium aluminate nanoflakes anchored functionalized carbon nanofiber nanocomposite for sensitive amperometric detection of food additive: Propyl gallate

The contemporary dietary pattern is ruined by taste enhancers, flavoring agents, and preservatives. Propyl gallate (PG) is an imperative phenolic antioxidant cast-off to inhibit the oxidative mutilation in foodstuffs thereby preventing rancidity. Determination and annihilation of PG are extensively concerned because of its probable lethal effects on human well-being. Herein, we report an electrochemical sensor using SrAl2O4/f-CNF nanocomposite as an efficient electrode modifier with peculiar synergistic quantum confinement effects supporting the formation of heterojunction to facilitate electron transportation between its counterparts. The structural, morphological, and crystalline features of SrAl2O4/f-CNF nanocomposite was thoroughly examined. The proposed sensor possesses a wide linear range (0.1–1104.75 µM) with a remarkably low limit of detection (0.075 µM) and sensitivity (1.142 µA⋅µM−1⋅cm−2) measured at 0.2 V (vs. Ag/AgCl). The reliability of this sensor was evidenced through real-time monitoring of PG in edible oil which is beneficial for food quality monitoring and dropping the danger of abuse of PG in foods.

Recent trends in the design and engineering of incorporated carbon nanofiber nanocomposites and their advanced applications – A review

Over the past few decades, carbon nanofibers (CNFs) have attracted attention in terms of technological development due to their remarkable mechanical and chemical characteristics as well as electrical conductivity. Currently, CNFs are being fabricated over electrospinning and catalytic approaches in two steps including stabilization and carbonization of polyacrylonitrile (PAN) nanofibers, respectively. Lately, the medical and industrial sectors dealing with quite expensive nanofibrous materials which have less flexibility in the functionalization of their chemical and surface characteristics for specific applications. To eliminate these limitations, CNFs are being multi-functionalized in diverse forms. This article reviews the recent progress in the design and synthesis of CNFs and their industrial and biomedical applications. In this article, the main focus is to review the recent breakthroughs in the field of CNFs, the modification of structural and chemical characteristics of CNFs used for various commercial applications. Furthermore, a brief summary is provided for various inexpensive substitutes for the currently existing materials.

Additive manufacturing of polyamide nanocomposites for electrostatic charge dissipation applications

Polyamide 6 (PA 6) nanocomposites are viable engineered nanocomposite materials with potential application in electrostatic discharge dissipation applications. Creating an electrically conductive path to dissipate electrostatic charges in such materials can be a viable solution to electrostatic discharge (ESD) concerns. The addition of nanofillers can also enhance mechanical properties of the parent polyamide 6, a structural thermoplastic ideal for 3D printing via fused deposition modelling (FDM). While improving the ESD capability, it is imperative to sustain the structural integrity of the nanocomposites. Hence, this study evaluated the mechanical, thermal, and electrical properties of 3D printed PA6 nanocomposites for electrostatic discharge applications. 3 and 5 wt% of carbon nanofibers (CNF) was compounded with PA6 using co-rotating twin screw extruder to produce 1.75 mm diameter monofilaments for fused deposition modelling (FDM). The test samples were printed using commercial-off-the-shelf (COTS) 3D printer, Lulzbot TAZ 6 FDM printer. Mechanical, electrical, and thermal characterization was carried out according to their respective ASTM standard. The tensile and flexural properties were enhanced by 3 wt% addition of CNF, but no significant improvement was observed at 5 wt%. The CNF nanocomposites exhibited good thermal stability and crystallization phenomenon at both loading levels. The volume resistivity of the of the PA6 matrix was reduced to order of 1011 and 1012 by 3 wt% and 5 wt% CNF addition respectively, which seems promising for manufacturing static discharge products.

Preparation of ferric oxide-aluminium oxide carbon nanofiber nanocomposites for ultrasound-assisted dispersive magnetic solid phase extraction of 17-beta estradiol in wastewater

Abstract In this work, Fe3O4-Al2O3@CNFs nanocomposite was synthesised and used as a nanosorbent in the ultrasound-assisted dispersive magnetic solid phase extraction (UA-DMSPE) of 17-beta estradiol (E2) in wastewater samples. The quantification of E2 was achieved using high performance liquid chromatography coupled with diode array detector (HPLC-DAD). Various parameters affecting the efficiency of this sample preparation technique were optimised to achieve excellent sensitivity and high recoveries of E2. Response surface methodology was utilised for optimisation of these parameters. Using the optimised conditions, the linear dynamic range was achieved in the range of 0.1–1000 μg L−1 and the correlation coefficient was found to be 0.9981. The preconcentration factor, enrichment factor, limit of detection (LOD) and limit of quantification (LOQ) were 67, 169, 0.025 μg L−1 and 0.083 μg L−1, respectively. The relative standard deviation (%RSD) for the intraday (n = 10) and interday (n = 5 working days) were 1.8% and 3.3%, respectively. The developed UA-DMSPE/HPLC-DAD method was applied for the preconcentration and determination of E2 in wastewater samples. The obtained results indicated that E2 was present in the wastewater samples.

Derivation of both EDLC and pseudocapacitance characteristics based on synergistic mixture of NiCo2O4 and hollow carbon nanofiber: An efficient electrode towards high energy density supercapacitor

In this study we fabricated a hollow carbon nanofiber (CNF) via a facile dual nozzle electrospinning process and directly used as low-cost and environmental friendly carbon source material, which were incorporated to NiCo2O4 (NCO). We designed a hybrid nanocomposite based on synergistic mixture of hollow structure CNF and spinel NCO, with 3D dandelion like morphology, hierarchical mesoporous surface, high specific surface area, and directly grown onto the surface of nickel foam substrate. We modified the structural properties of hybrid NCO–CNF nanocomposite in aim to improve its overall electrochemical performance towards supercapacitor application. In here, we fabricated our hollow CNF using dual concentric nozzle electrospinning method, comprising of poly (vinyl pyrrolidone) (PVP) as soluble core and polyacrylonitrile (PAN) as shell. It was essential in our study to fully leach out the PVP to obtain a hollow structure: this hollow structure of CNF provided a conductive network that guaranteed the high speed movement of electron/electrolyte. Furthermore, the overall specific capacitance and energy density of the hybrid NCO–CNF electrode were remarkably boost up due to the derivation of both electric double layer capacitance and pseudocapacitance characteristics based on the synergistic mixture of graphitic carbon and transition metal oxides. The fabricated binder-free hybrid NCO–CNF electrode displayed efficient charge transfer and achieved outstanding specific capacitance and energy density as high as 1188.19 F g−1 and 37.23 W h kg−1, respectively, even at high current density of 50 A g−1.

Hierarchical hollow urchin-like structured MnO2 microsphere/carbon nanofiber composites as anode materials for Li-ion batteries

In this work, novel hollow urchin-like MnO2 microspheres (u-MnO2), consisting of a hollow core with nanotubes, are synthesized by a simple hydrothermal process. The morphology of the MnO2 structures could be tuned from round particles to a hierarchical hollow urchin structure by controlling the hydrothermal reaction time, with no need for surfactant or templates. The nanostructures of the obtained u-MnO2 are characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The X-ray diffraction (XRD) pattern of the u-MnO2 reveals a tetragonal structure of α-MnO2. The carbon nanofibers (CNFs) are uniformly deposited on u-MnO2 to improve the electrical conductivity and to utilize the hierarchical architecture of u-MnO2. As the anode electrode of Li-ion batteries, the u-MnO2/CNFs nanocomposites exhibit discharge capacity of 988 mAh·g−1 after 100 cycles with a good rate capability. The superior electrochemical performances of the u-MnO2/CNFs nanocomposites can be attributed to the hierarchical urchin-like structures and the superior electrical conductivity of the nanocomposites, which can facilitate fast electron and ion transport and accommodate a large volume change during charge/discharge.

Effect of carbon nanofibers on electrode performance of symmetric supercapcitors with composite α-MnO2 nanorods

α-MnO2 nanorods have been grown on the surface of carbon nanofibers (CNFs) for enhancing the electrical conductivity of MnO2. We have synthesized α-MnO2/CNF (0–5 wt%) nanocomposites using a co-precipitation method. The x-ray diffraction results confirm the formation of a single phase α-MnO2 and SEM/TEM images reveal the formation of α-MnO2 nanorods, whose size depends on the amount of CNF in the nanocomposite. Both the surface area and electrical conductivity of nanocomposites are found to be strongly influenced by the presence of CNF. While α-MnO2/CNF(1.25 wt%) exhibits the largest surface area (381 m2/g) and only a modest increase in the electrical conductivity compared to pure α-MnO2 nanorods, the α-MnO2/CNF(5 wt%) shows the least surface area (131 m2/g) but an order of magnitude higher electrical conductivity (0.67 S/cm). Cyclic voltammetry measurements show improved performance (higher specific capacitance and better cyclic stability) in all α-MnO2/CNF supercapacitors compared to that of pure α-MnO2. Ragone plot shows that although α-MnO2/CNF(1.25 wt%) exhibits the highest specific capacitance (313 F/g at 1 A/g) and hence the highest energy density of 32.8 Wh/kg, it has the least power density of 4250 W/kg. On the other hand, α-MnO2/CNF(5 wt%) shows the least energy density of 7.9 Wh/kg but with a higher power density of 8478 W/kg compared to α-MnO2/CNF(1.25 wt%). Our studies demonstrate that one can optimize both energy and power densities by controlling the amount of CNF in the nanocomposites.

MnO2 Nanoparticles and Carbon Nanofibers Nanocomposites with High Sensing Performance Toward Glucose

By combining the advantages of manganese dioxide nanoparticles (MnO2 NPs) and carbon nanofibers (CNFs), a biosensing electrode surface as a high-performance enzyme biosensor is designed in this work. MnO2 NPs and CNFs nanocomposites (MnO2–CNFs) were prepared by using a simple hydrothermal method and then were characterized by scanning electron microscopy, powder X-ray diffraction, fourier transform infrared spectroscopy, energy dispersive spectrometry and electrochemisty. The results showed that MnO2 NPs are uniformly attached to the surface of CNFs. Meanwhile, the MnO2–CNFs nanocomposites as a supporting matrix can provide an efficient and advantageous platform for electrochemical sensing applications. On the basis of the improved sensitivity of MnO2–CNFs modified electrode toward H2O2 at low overpotential, a MnO2–CNFs based glucose biosensor was fabricated by monitoring H2O2 produced by an enzymatic reaction between glucose oxidase and glucose. The constructed biosensor exhibited a linear calibration graph for glucose in a concentration range of 0.08–4.6 mM and a low detection limit of 0.015 mM. In addition, the biosensor showed other excellent characteristics, such as high sensitivity and selectivity, short response time, and the relative low apparent Michaelis–Menten constant. Analysis of human urine spiked with glucose at different concentration levels yielded recoveries between 101.0 and 104.8%.

Synthesis of rose like structured LaCoO3 assisted functionalized carbon nanofiber nanocomposite for efficient electrochemical detection of anti-inflammatory drug 4-aminoantipyrine

For the first time, lanthanum cobalt oxide was prepared in a rose like structure and assisted with functionalized carbon nanofiber (f-CNF/LaCoO3) using the hydrothermal technique. Further, the prepared f-CNF/LaCoO3 was used as an electrode material for sensitive electrochemical detection of non-steroid anti-inflammatory drug 4-Aminoantipyrine (4-AAP). The formation of f-CNF/LaCoO3 nanocomposite was characterized by using various analytical techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). In addition, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and amperometric i-t technique were performed to scrutinize the electrochemical activity of f-CNF/LaCoO3/GCE toward the electrochemical oxidation of 4-AAP. The proposed sensor exhibits excellent electrochemical performance with wide linear range (0.001–1374.87 μM) and ultra low detection limit of as low as concentration (1.0 nM) of 4-AAP. Moreover, the excellent selectivity of the sensor was recorded and the practicability of the sensor also demonstrated for detection of 4-AAP in the human urine sample.

Electrochemical Determination of Glucose Using a Platinum–Palladium Nanoparticle Carbon Nanofiber Glassy Carbon Electrode

ABSTRACTA novel platinum–palladium nanoparticle-decorated carbon nanofiber nanocomposite was greenly prepared by attaching the nanoparticles to the nanofibers for the preparation of glucose biosensors. The platinum–palladium bimetallic nanoparticle-modified carbon nanofiber nanocomposite was characterized by transmission electron microscopy, X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. The glucose biosensor was constructed by immobilizing glucose oxidase on the nanocomposite-modified glassy carbon electrode by cross-linking with glutaraldehyde. The resulting biosensor exhibited a good response to glucose with a wide linear range from 2.5 × 10−6 to 1.3 × 10−2 M with a high sensitivity of 154.6 µA mM−1 cm−2 and a detection limit of 0.7 µM. This biosensor was shown to offer good accuracy, precision, and reproducibility. The determination of glucose in human serum by the modified electrode was in good agreement with standard values. The nanocomposite electrode offers a suitable platform for the determination of glucose.

N-, Fe-Doped carbon sphere/oriented carbon nanofiber nanocomposite with synergistically enhanced electrochemical activities

Excellent electrocatalyst for oxygen reduction in zinc–air batteries: N-, Fe-doped carbon sphere/oriented carbon nanofiber nanocomposite was prepared. The typical product is a competitive alternative to commercial Pt/C in the practical application of zinc–air batteries.

Fabrication of a novel visible-light-driven photocatalyst Ag-AgI-TiO2 nanoparticles supported on carbon nanofibers

Novel visible-light-driven photocatalysts Ag-AgI-TiO2 nanoparticles embedded onto carbon nanofibers were successfully prepared. Electrospinning technology followed by high-temperature calcination was adopted for the fabrication of carbon nanofibers (CNFs) acting as a supporter. Ag-TiO2/CNFs nanocomposites were prepared by combining in situ reduction with physical adsorption process. Ag-AgI-TiO2/CNFs were synthesized by oxidizing some silver nanoparticles (Ag NPs) contained in Ag-TiO2/CNFs to silver iodine (AgI) via chemical oxidation method using iodine (I2) as oxidation agents. The as-prepared nanocomposites were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (DRS), and Fourier transform infrared spectroscopy (FTIR). The as-fabricated Ag-AgI-TiO2/CNFs showed high efficient adsorption and photocatalytic activity for decomposition of methyl orange (MO), acid red 18 (AR18), methylene blue (MB), and fluorescence sodium under visible light irradiation, which were attributed to the synergistic effects between the high adsorption capacity, good conductivity of carbon nanofibers, and the extraordinary plasma effect of Ag-AgI nanoparticles. In addition, the as-prepared composites could be easily separated from the solution phase due to the large length–diameter ratio of CNFs. The mechanism for the enhanced photocatalytic activity concerned with Ag-AgI-TiO2/CNFs was proposed.

Sensitive Hydrazine Electrochemical Biosensor Based on a Porous Chitosan–Carbon Nanofiber Nanocomposite Modified Electrode

A novel electrochemically-based biosensor was developed for the determination of hydrazine by modifying a glassy carbon electrode with an aqueous dispersion of carboxylic group-functionalized carbon nanofiber/chitosan solution, and then absorbing hemoglobin on the surface of chitosan-carbon nanofibers. Nafion was used to coat the hemoglobin membrane. The interactions of hemoglobin and the nafion/chitosan-carbon nanofibers were investigated by ultraviolet-visible absorption, infrared, and circular dichroism spectroscopies. The results indicated that the native structure of hemoglobin was retained post-immobilization. The circular dichroism results showed that the α-helical structure of hemoglobin was preserved though a small change was observed in the presence of the nafion/chitosan-carbon nanofibers. The modified nanofibers were further characterized by scanning electron microscopy, electron impendence spectroscopy, and cyclic voltammetry. The electrocatalytic mechanism of hemoglobin to the oxidation of hydrazine was investigated and an irreversible diffusion-controlled electrode process was obtained. The electron transfer rate constant (ks), transfer coefficient (α), and Michaelis–Menten constant (Km) were also evaluated. The peak current of the catalytic oxidation was linear with hydrazine concentration from 3.722 × 10−5 to 1.601 × 10−3 molar with a correlation coefficient of 0.995. The detection limit was estimated to be 2.7 micromoles per liter. The sensitivity, stability, and reproducibility of the nafion/hemoglobin/chitosan-carbon nanofiber/glassy carbon electrode for the oxidation of hydrazine were also investigated.

Thermal properties of carbon nanofiber reinforced high-density polyethylene nanocomposites

Reinforcing polymers with the appropriate nanofillers is an effective way to obtain a variety of enhanced material properties. In this paper, high-density polyethylene nanocomposites reinforced with either pristine or silane-treated carbon nanofibers at various weight percentages (0.5 wt%, 1 wt%, and 3 wt%) were fabricated through melt-mixing and compressive processing. Silane coatings with two thicknesses, 2.8 nm and 46 nm, were applied on the oxidized carbon nanofibers to improve the interfacial bonding between the carbon nanofibers and the matrix. Scanning electron microscopy and transmission electron microscopy demonstrated the dispersion of carbon nanofibers and the strongly improved interfacial adhesion between the carbon nanofibers and high-density polyethylene matrix due to the silane coating. The thermal properties of high-density polyethylene / carbon nanofiber nanocomposites were characterized and compared with those of the neat high-density polyethylene. The measurement results showed that the thermal conductivity of the high-density polyethylene /carbon nanofiber nanocomposites increased with the carbon nanofiber loading. The enhancement of thermal conductivity was not only due to the high thermal conductivity of carbon nanofibers but also due to the interfacial quality between the carbon nanofibers and the high-density polyethylene matrix. The interfacial thermal contact resistance between the carbon nanofibers and the matrix was determined to be in the range of [Formula: see text] to [Formula: see text]. Furthermore, the coefficient of thermal expansion of the nanocomposite was found to be reduced by the incorporation of carbon nanofibers.

Effect of filler functionalization on thermo-mechanical properties of polyamide-12/carbon nanofibers composites: a study of filler–matrix molecular interactions

The effect of carbon nanofiber (CNF) functionalization on the thermo-mechanical properties of polyamide-12/CNF nanocomposites was investigated. Three main different surface treatments were performed to obtain CNF-OH (OH rich), CNF-Silane (C6H5Si–O–), and CNF-peroxide. CNF modified with poly-(tert-butyl acrylate) chains grown from the surface via ATRP (atom transfer radical polymerization) were also prepared and tested. The modified CNFs and neat CNFs were used as fillers in polyamide-12 nanocomposites and the properties of the ensuing materials were characterized and compared. Universal tensile tests demonstrated a substantial increase (up to 20 %) of the yield strength, without reduction of the final elongation, for all functionalized samples tested within 1 wt% filler content. Further evidences of mechanical properties improvement were given by dynamic mechanical thermal analyses. CNFs functionalized with poly-(tert-butyl acrylate) and silane exhibited the best performance with stiffening and strengthening at low (≤1 wt%) filler loadings, via a partial decrease of the intensity of β-transitions attributed to favorable interactions between the functional groups on the surface of functionalized CNFs and polyamide-12. CNFs treated with peroxide proved to be the most simple preparation technique and the ensuing nanocomposites exhibited the highest storage modulus at high (5 wt%) filler content. Theoretical simulations using the micro-mechanics model were used to predict the Young modulus of the composites and compare them with experimental data. The results obtained suggest a synergistic effect between the matrix and the filler enhanced by surface functionalization.

Synthesis and electrochemical performance of MnO2/CNTs–embedded carbon nanofibers nanocomposites for supercapacitors

MnO2/carbon nanotubes (CNTs)–embedded carbon nanofibers (CNFs) nanocomposites (MnO2/CNTs–CNFs) have been prepared using electrospinning and in situ redox deposition technique. The as-prepared nanocomposites were directly employed as freestanding electrodes to evaluate the electrochemical properties. Results showed that the nanoscopic MnO2 deposits were incorporated uniformly into the CNTs–embedded CNFs network structure, which hold a great promise for high-performance supercapacitor applications. Compared to the pure CNFs substrate, the improved electric conductivity of CNTs–embedded CNFs substrate enabled a better utilization of MnO2 coating, thus resulting in higher specific capacitance (374F/g) and better rate capability (53.4%). Excellent capacitance retention of 94% of the initial capacitance after 1000cycles was achieved on the freestanding MnO2/CNTs–CNFs nanocomposites electrode. The specific capacitance was found to increase significantly with the increase in the electrolyte temperature, which offered an insight into the practical supercapacitor applications.