Carbon Nanotube Composite Electrode Research Articles

Bi-objective optimization of an EDM process with Cu-MWCNT composite tool using single-valued neutrosophic grey relational analysis

Purpose In many of today’s manufacturing industries, such as automobile, aerospace, defence, die and mould making, medical and electrical discharge machining (EDM) has emerged as an effective material removal process. In this process, a series of discontinuous electric discharges is used for removing material from the workpiece in the form of craters generating a replica of the tool into the workpiece in a dielectric environment. Appropriate selection of the tool electrode material and combination of input parameters is an important requirement for performance enhancement of an EDM process. This paper aims to optimize an EDM process using single-valued neutrosophic grey relational analysis using Cu-multi-walled carbon nanotube (Cu-MWCNT) composite tool electrode. Design/methodology/approach This paper proposes the application of grey relational analysis (GRA) in a single-valued neutrosophic fuzzy environment to identify the optimal parametric intermix of an EDM process while considering Cu-MWCNT composite as the tool electrode material. Based on Taguchi’s L9 orthogonal array, nine experiments are conducted at varying combinations of four EDM parameters, i.e. pulse-on time, duty factor, discharge current and gap voltage, with subsequent measurement of two responses, i.e. material removal rate (MRR) and tool wear rate (TWR). The electrodeposition process is used to fabricate the Cu-MWCNT composite tool. Findings It is noticed that both the responses would be simultaneously optimized at higher levels of pulse-on time (38 µs) and duty factor (8), moderate level of discharge current (5 A) and lower level of gap voltage (30 V). During bi-objective optimization (maximization of MRR and minimization of TWR) of the said EDM process, the achieved values of MRR and TWR are 243.74 mm3/min and 0.001034 g/min, respectively. Originality/value Keeping in mind the type of response under consideration, their measured values for each of the EDM experiments are expressed in terms of linguistic variables which are subsequently converted into single-valued neutrosophic numbers. Integration of GRA with single-valued neutrosophic sets would help in optimizing the said EDM process with the Cu-MWCNT composite tool while simultaneously considering truth-membership, indeterminacy membership and falsity-membership degrees in a human-centric uncertain decision-making environment.

Dip-coated graphene nanoplatelets and multiwall carbon nanotubes composite ink electrode for metal-free paper-based flexible heating device

A paper-based flexible heating device (PFHD - paper-based flexible heating device) composed of a cellulose paper substrate and a carbonaceous functional electrode is reported. The functional composite electrodes containing graphene nanoplatelets (GNP - graphene nanoplatelets) and multi-walled carbon nanotubes (MWCNT) in various compositional ratios were prepared by dip-coating the oxygen plasma-treated paper substrate into the composite ink, and subsequently dried at 110 ℃ for 30 min to prepare PFHDs. The electrochemical characteristics and heat generation properties of PFHDs indicated that the GNP component in the functional electrode enhanced the electrical conductivity of the electrode, and the physical stability was enhanced mainly by the MWCNT component. Accordingly, PFHD0.33 which contains 33 % GNP and 67 % MWCNT in the functional electrode shows excellent heating performance with high stability and areal rated power of 0.68 W cm−2 (specific rated power = 45 W g−1). The measured sensitivity of PFHD0.33 is 31.50 ℃ V−1 at the applied DC voltage of 0.1–2.0 V.

Preparation of Gold Nanoparticles via Anodic Stripping of Copper Underpotential Deposition in Bulk Gold Electrodeposition for High-Performance Electrochemical Sensing of Bisphenol A.

Bisphenol A is one of the most widely used industrial compounds. Over the years, it has raised severe concern as a potential hazard to the human endocrine system and the environment. Developing robust and easy-to-use sensors for bisphenol A is important in various areas, such as controlling and monitoring water purification and sewage water systems, food safety monitoring, etc. Here, we report an electrochemical method to fabricate a bisphenol A (BPA) sensor based on a modified Au nanoparticles/multiwalled carbon nanotubes composite electrocatalyst electrode (AuCu-UPD/MWCNTs/GCE). Firstly, the Au-Cu alloy was prepared via a convenient and controllable Cu underpotential/bulk Au co-electrodeposition on a multiwalled modified carbon nanotubes glassy carbon electrode (GCE). Then, the AuCu-UPD/MWCNTs/GCE was obtained via the electrochemical anodic stripping of Cu underpotential deposition (UPD). Our novel prepared sensor enables the high-electrocatalytic and high-performance sensing of BPA. Under optimal conditions, the modified electrode showed a two-segment linear response from 0.01 to 1 µM and 1 to 20 µM with a limit of detection (LOD) of 2.43 nM based on differential pulse voltammetry (DPV). Determination of BPA in real water samples using AuCu-UPD/MWCNTs/GCE yielded satisfactory results. The proposed electrochemical sensor is promising for the development of a simple, low-cost water quality monitoring system for the detection of BPA in ambient water samples.

Nitrogen and oxygen co-doped porous biocarbon@sulfur/carbon nanotubes as cathodes for high-performance lithium-sulfur batteries

Practical applications of lithium-sulfur batteries (LSBs) are limited due to the shuttle effect and the low conductivity of sulfur (S) and lithium polysulfide (LiPS). Currently, porous carbon materials doped with heteroatoms show extraordinary potential in this regard. Therefore, using KOH activation, we successfully prepared porous London Plane seed stems biochar (LPSC) with nitrogen and oxygen co-doping as the S carrier. We used carbon nanotubes (CNTs) as electrode coatings to improve the conductivity and suppress the shuttle effect. The results showed that the LPSC@S/CNTs composite electrode had an initial discharge capacity of 1090.4 mAh g−1 at 0.05 C. Furthermore, the capacity remained at 86.0 % after 300 cycles. This study provides a promising and sustainable approach to high-performance energy storage solutions.

Development of Lithium/Sodium-Ion Battery Electrodes Based on Solvent Engineered Tin(II) Oxide Nanomaterials

With the global economy pushing towards a greener and cleaner energy future for the world, renewable energy storage technologies must continue to develop and improve to allow for a seamless transition from the ways of the past to a carbon neutral future. To this end, renewable battery technology and in particular the capacity of the anode must be improved. Furthermore this improvement must be made across various battery technologies (Lithium/Sodium-ion) and be cost-effective to allow for its widespread implementation and use worldwide.In this work, Tin(II) Oxide (SnO)/single wall carbon nanotube (SWCNT) composite electrodes are analysed as a possible alternative dual anode material for both lithium (LIB) and sodium-ion batteries (NIB). The LIB is limited by the current commercial anode material of graphite with a relatively low theoretical capacity of 372 mAh g-1 whilst NIBs use hard carbon with a capacity of roughly 300 mAh g-1. Alloy/de-alloy materials are envisioned to be a suitable candidate for next generation LIBs/NIBs due to their large specific capacities (875mAh g-1/ 847 mAh g-1 for SnO respectively) although major drawbacks concern the poor cycling life associated with the volume change and the associated irreversible capacity. To overcome such issues the downsizing of materials and the fabrication of composites which incorporate both lithium active and inactive material are viewed as promising solutions. Nanostructured metal oxides, forming an inactive oxide matrix are appealing candidates.Through the implementation of a solvent engineered wet chemistry synthesis, various layered SnO microparticles are produced with several morphologies well-suited to energy storage applications. This synthesis method is facile, scalable and is favourable in comparison to hydrothermal synthesese normally used to synthesise nanomaterials. While SWCNTs are themselves not suited towards energy storage applications, their incorporation in the electrodes allows them to act as a conductive additive at a lower weight loading than other conventional carbon sources (carbon black/graphite), presenting a more effective strategy to form an effective electrical percolation network while also removing the need for polymer binders/copper current collector.The optimised morphology of SnO produces a high capacity, high rate and stable anode for LIB technology. An initial coloumbic efficiency (ICE) in excess of 80% is recorded and a stable cycling capacity of 815 mAh g-1 at 0.5C after 300 cycles is also achieved, demonstrating its long term stability. A maximum capacity of 980 mAh g-1 is recorded at 0.1C, whilst high rate capacities of 775, 671 and 364 mAh g-1 are recorded at 1,2 and 5C respectively. Furthermore a full-cell is composed with a NMC cathode to demonstrate a potential full-cell real world device. As an NIB anode, a maximum capacity of 568 mAh g-1 was recorded at 0.05C, whilst a low ICE of 50% proves an issue under further investigation. Furthermore a cycling capacity of 595 mAh g-1 is recorded after 50 cycles at 0.1C, dropping to 360 mAh g-1 at 100 cycles which is still in excess of that recorded for hard carbon in NIBs.A high capacity, scalable and cost effective anode has been developed that is interchangeable between LIBs/NIBs and exceeds the performance of the current commercial anodes. Reference s : [1] S. Jaśkaniec, S. R. Kavanagh, S. Ryan, J. Coelho, C. Hobbs, A. Walsh, D. O. Scanlon and V. Nicolosi, npj 2D Mater. Appl., 2021, 5, 27. [2] J. H. Shin and J. Y. Song, Nano Converg., 2016, 3(1), 9. [3] F. Zhang, J. Zhu, D. Zhang, U. Schwingenschlögl and H. N. Alshareef, Nano Lett., 2017, 17, 1302–1311.

Construction and electrochemical properties of carbon nanotube composite Mn-MOFs materials electrode for high-performance flexible supercapacitors

Metal organic frameworks (MOFs) as electrode materials for supercapacitors have attracted extensive attention due to their porous structure. However, the poor conductivity of MOFs limits the charge transfer. In this work, Mn-MOF/carbon nanotube (CNT) composites were grown directly on carbon cloth (CC) in one step by the traditional hydrothermal synthesis of MOFs to improve the electrical conductivity of Mn-MOFs. The structural and performance tests show that CNTs, as a conductive backbone, can connect Mn-MOFs to each other, which can obviously solve the problem of poor conductivity of MOF materials. The Mn-MOFs/CNTs/CC electrodes show a larger specific capacitance and excellent cycling stability by electrochemical tests. Compared to the original Mn-MOF electrode, the surface capacitance obtained increases from 188.8 mF·cm−2 to 385.8 mF·cm−2 at a current density of 0.8 mA·cm−2 and maintains a high capacitance retention of 118% after 5000 charge/discharge cycles at a current density of 5 mA·cm−2. This work confirms that the in- situ synthesis of MOFs and CNTs has promising applications in fabric-based flexible supercapacitors.

Fabrication of Co3O4 particles‐modified multi‐walled carbon nanotube and poly(phenosafranine) composite electrode for selective and sensitive rutin detection

AbstractThe preparation and characterisation of a new composite electrode with Co3O4 particles‐modified multi‐walled carbon nanotube (MWCNT) and poly(phenosafranine), as well as its novel application for the voltammetric detection of rutin was described. The resulting composite electrode was characterised using scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). In the optimised experimental conditions, the oxidation peak current (Ipa) of rutin showed a linear increase in concentration, between 0.008–0.6 and 0.80–6.0 μmol L−1, with a detection limit of 0.00379 μmol L−1. Due to its good selectivity and stability, the composite electrode was successfully applied in detecting rutin in pharmaceutical formulations.

Protein Adsorption and Its Effects on Electroanalytical Performance of Nanocellulose/Carbon Nanotube Composite Electrodes.

Protein fouling is a critical issue in the development of electrochemical sensors for medical applications, as it can significantly impact their sensitivity, stability, and reliability. Modifying planar electrodes with conductive nanomaterials that possess a high surface area, such as carbon nanotubes (CNTs), has been shown to significantly improve fouling resistance and sensitivity. However, the inherent hydrophobicity of CNTs and their poor dispersibility in solvents pose challenges in optimizing such electrode architectures for maximum sensitivity. Fortunately, nanocellulosic materials offer an efficient and sustainable approach to achieving effective functional and hybrid nanoscale architectures by enabling stable aqueous dispersions of carbon nanomaterials. Additionally, the inherent hygroscopicity and fouling-resistant nature of nanocellulosic materials can provide superior functionalities in such composites. In this study, we evaluate the fouling behavior of two nanocellulose (NC)/multiwalled carbon nanotube (MWCNT) composite electrode systems: one using sulfated cellulose nanofibers and another using sulfated cellulose nanocrystals. We compare these composites to commercial MWCNT electrodes without nanocellulose and analyze their behavior in physiologically relevant fouling environments of varying complexity using common outer- and inner-sphere redox probes. Additionally, we use quartz crystal microgravimetry with dissipation monitoring (QCM-D) to investigate the behavior of amorphous carbon surfaces and nanocellulosic materials in fouling environments. Our results demonstrate that the NC/MWCNT composite electrodes provide significant advantages for measurement reliability, sensitivity, and selectivity over only MWCNT-based electrodes, even in complex physiological monitoring environments such as human plasma.

Planar on-chip micro-supercapacitors based on reduced graphene oxide and carbon nanotube by liquid–air interface self-assembly and photolithography

Recently, the development of miniaturized electronic devices has accelerated the demand for the rate capability of planar on-chip micro-supercapacitors (POMSs). The POMSs based on reduced graphene oxide and carbon nanotube (rGO/CNT) composite electrodes (rGO/CNT-POMSs) were manufactured in the work and detailed electrochemical tests of devices were carried out over a wide range of scanning rates (0.01–10000 V s−1). The rGO/CNT composite electrode films without binder were prepared on silicon substrates by a modified liquid–air interface self-assembly method and a hydroiodic acid reduction method. The electrodes were fabricated into interdigital structure with 50 μm width of electrode and gap of electrode by photolithography. Interdigital POMSs based on different electrodes were prepared by gold sputtering on the electrode lugs. The area capacitance of the rGO/CNT-POMSs was 28.62 μF cm−2. They also had 0.004 μWh cm−2 of energy density and 1.068 μW cm−2 of power density. In addition, the charge–discharge time constant of the device was only 5.6 μs, and the charge–discharge rate was very quick. After 10,000 cycles of charge–discharge, the capacitance retention rate was still above 88%. At the ultra-high scan rate of 10000 V s−1, the devices still worked well. Compared with the POMSs based on reduced graphene oxide electrodes (rGO-POMSs) and the POMSs based on carbon nanotube electrodes (CNT-POMSs), the introduction of the CNT significantly increased the area capacitance, energy density and power density of rGO/CNT-POMSs, and significantly shortened the charge–discharge time constant. This indicated that the rGO/CNT composite electrodes had a good application prospect in the micro-chip accumulator devices.

Effect of Carbon Nanotubes on the Na+ Intercalation Capacity of Binder Free Mn2V2O7-CNTs Electrode: A Structural Investigation

Improvements in sodium intercalation in sodium cathodes have been debated in recent years. In the present work, we delineate the significant effect of the carbon nanotubes (CNTs) and their weight percent in the intercalation capacity of the binder-free manganese vanadium oxide (MVO)-CNTs composite electrodes. The performance modification of the electrode is discussed taking into account the cathode electrolyte interphase (CEI) layer under optimal performance. We observe an intermittent distribution of the chemical phases on the CEI, formed on these electrodes after several cycles. The bulk and superficial structure of pristine and Na+ cycled electrodes were identified via micro-Raman scattering and Scanning X-ray Photoelectron Microscopy. We show that the inhomogeneous CEI layer distribution strongly depends on the CNTs weight percentage ratio in an electrode nano-composite. The capacity fading of MVO-CNTs appears to be associated with the dissolution of the Mn2O3 phase, leading to electrode deterioration. This effect is particularly observed in electrodes with low weight percentage of the CNTs in which the tubular topology of the CNTs are distorted due to the MVO decoration. These results can deepen the understanding of the CNTs role on the intercalation mechanism and capacity of the electrode, where there are variations in the mass ratio of CNTs and the active material.

Dye-sensitized solar cells based on highly catalytic CNTs/Ti3C2Tx MXenes composite counter electrode.

Establishing stable and efficient Pt-free counter electrodes (CEs) is an important challenge for dye-sensitized solar cells (DSSCs). Ti3C2Tx MXene, with its high catalytic activity and conductivity, has gained attention as a CE in DSSCs. The focus of this paper is on the preparation of Ti3C2Tx decorated carbon nanotubes (CNTs) composite electrode materials (CNTs/Ti3C2Tx), and testing their performance as CEs in DSSCs. Through a series of electrochemical tests, a CNTs/Ti3C2Tx CE exhibits good electrocatalytic activity toward iodine-based electrolytes with low charge transfer resistance, which is close to the performance of a Pt CE. The photoelectric conversion efficiency (PCE) of the CNTs/Ti3C2Tx (1.0 wt%) CE-based DSSCs reaches 5.83%, which is much higher than that of the CNTs CE (3.70%), and approximates that of the Pt CE (6.61%). We attribute the improved performance to the synergistic effect of the excellent conductivity and unique two-dimensional chemical structure of Ti3C2Tx MXene. Moreover, the photostability test of continuous light exposure shows that the CNTs/Ti3C2Tx-1.0 wt% (C/T-1.0 wt%) CE exhibits good stability to the electrolyte. Therefore, CNTs/Ti3C2Tx composites can be used as an efficient Pt-free CE for DSSCs in the future.

Life and failure of oriented carbon nanotubes composite electrode for resistance spot welding

In view of the poor weldability of electrodes in resistance spot welding (RSW) of galvanized steel sheets, the life of oriented multi-walled carbon nanotubes reinforced Cu matrix composites (Cu@MWCNTs/Cu) electrodes was studied, in which Cu coated multi-walled carbon nanotubes (MWCNTs) are arranged along the flow direction of working electric/force. By analyzing the macro/microscopic morphology, microstructure, hardness, texture and composition of the failed composite electrodes and the commercially CuCrZr electrode, the mechanism of the weldability enhancement and failure of electrodes was discussed. The results show that the life of Cu@MWCNTs/Cu electrodes (2150 welds) is 3 times longer than that of CuCrZr electrode (600 welds), and the degradation rate is much slower. The hardness of Cu@MWCNTs/Cu electrodes is 30–40Hv higher. The content of recrystallized and recovery grains of Cu@MWCNTs/Cu electrodes is less. This is due to the pinning effect of MWCNTs, and straight and long MWCNTs are arranged along the electrical/force direction. These improve the hardness, mechanical properties, conductivity, and resistance to thermal deformation, cracking, and pitting of Cu@MWCNTs/Cu electrodes, which effectively slows down the failure rate and makes the spot welding life of Cu@MWCNTs/Cu electrodes longer. This work provides a new idea for the application of CNTs/Cu composites.

Thin carbon nanotube coiled around thick branched carbon nanotube composite electrodes for high-performance and flexible supercapacitors

TCNT/BCNT composites are designed for flexible supercapacitors that exhibit exceptional cycling performance and remarkable flexibility over 10 000 cycles under bending.

Hydrothermal synthesis of CuO@MnO2 on nitrogen-doped multiwalled carbon nanotube composite electrodes for supercapacitor applications

Nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs) have been used to fabricate nanostructured materials for various energy devices, such as supercapacitors, sensors, batteries, and electrocatalysts. Nitrogen-doped carbon-based electrodes have been widely used to improve supercapacitor applications via various chemical approaches. Based on previous studies, CuO@MnO2 and CuO@MnO2/N-MWCNT composites were synthesized using a sonication-supported hydrothermal reaction process to evaluate their supercapacitor properties. The structural and morphological properties of the synthesized composite materials were characterized via Raman spectroscopy, XRD, SEM, and SEM–EDX, and the morphological properties of the composite materials were confirmed by the nanostructured composite at the nanometer scale. The CuO@MnO2 and CuO@MnO2/N-MWCNT composite electrodes were fabricated in a three-electrode configuration, and electrochemical analysis was performed via CV, GCD, and EIS. The composite electrodes exhibited the specific capacitance of ~ 184 F g−1 at 0.5 A g−1 in the presence of a 5 M KOH electrolyte for the three-electrode supercapacitor application. Furthermore, it exhibited significantly improved specific capacitances and excellent cycling stability up to 5000 GCD cycles, with a 98.5% capacity retention.

Increasing the Pressure‐Free Stripping Capacity of the Lithium Metal Anode in Solid‐State‐Batteries by Carbon Nanotubes

AbstractLithium metal is the key anode material for solid‐state‐batteries as its successful implementation will drastically increase their energy and power densities. However, anode contact loss during stripping leads to dendrites upon plating and subsequent cell failure. Design strategies to mitigate these issues are crucial to enable the use of lithium metal anodes. This paper reports the dissolution kinetics of composite anodes made of lithium metal and carbon nanotubes (CNTs) with a garnet‐type solid electrolyte (SE). In addition to an enhancement of the effective diffusion within the anode, its dissolution is fundamentally changed from being 2D to 3D. By maintaining contact with the SE, the CNTs facilitate lithium transport to the interface, which yields more than 20 mAh cm−2 discharge capacity at 100 µA cm−2 without the application of external stack pressure (>1 MPa). Conclusions drawn from electrochemical data on the anode microstructure are validated using cryo‐focused‐ion‐beam scanning electron microscopy and correlated with the mechanical properties. Micro‐indentation, acoustic analysis, and stress–strain testing show that mechanical properties of the anode, like yield strength and hardness, are adjustable. Overall, it is shown that the mechanical and electrochemical properties of Li–CNT composite electrodes can be tailored to suit the requirements of a practical cell.

Facile synthesis of NiFe2O4 nanoparticle with carbon nanotube composite electrodes for high-performance asymmetric supercapacitor

The supercapacitor (SCs) is being developed as a cost-effective and efficient energy storage device. Any synergistic impact on binary metal oxide with a CNT composite has been regarded as the desired technique to increase energy storage in recent studies. Herein, we prepared spinel NiFe2O4 enclosed carbon nanotube (CNT) nanocomposites using chemical approach. The physiochemical characteristics of the prepared NiFe2O4/CNT nanocomposite and NiFe2O4 nanoparticle were studied using a variable of analytical techniques. The spinel NiFe2O4/CNT nanocomposite and NiFe2O4 nanoparticle modified electrode were then examined in a 2 M KOH electrolyte using a three-electrode setup. In particular, the specific capacitance of the spinel NiFe2O4/CNT nanocomposite modified single electrode was 670 F g−1 (CV) and 343 F g−1 (GCD) with retention of 89.16% after 5000 cycles, respectively. Furthermore, the specific capacitance of the spinel NiFe2O4/CNT nanocomposite as a cathode and activated carbon as an anode of a two-electrode device was 118.36 F g−1 (CV) and 85.93 F g−1 (GCD), respectively, with an energy density of 23.39 W h kg−1 vs. power density of 466.66 W kg−1. Then the CNT improves the energy storage activity of NiFe2O4 nanocomposite exhibit through exchange stabilization of energy storage performance.

Using coarse-grain MD to study the trade-off between surface area and mass transport in aqueous Li-O2 battery using functionalized CNT

The discharge performance of lithium-oxygen battery with ultrahigh theoretical capacity is not satisfactory, and its mass transfer process is restricted by many factors such as cathode structure and hydrophilic/hydrophobic properties. Here, the mass transfer process at the interface composed of hydrophobic carbon nanotubes (CNTs) electrode, hydrophilic carboxylic carbon nanotubes (COOH-CNTs) electrode, composite electrode and aqueous electrolyte was studied by coarse-grain molecular dynamics (CGMD) simulation. The mesoscopic scale simulation method enabled this study to discuss the hydrophilicity/hydrophobicity of the two-phase interface on the cathode side in order to improve the mass transfer and diffusion of reactants. The morphology of hydrophobic/hydrophilic electrode in aqueous electrolyte and the mass transfer conditions of reactants under different hydrophilic conditions were analyzed. The results showed that hydrophobic CNTs exhibited aggregation behavior and formed pore channels in aqueous electrolyte, which was conducive to the transport of ions and dissolved oxygen, while hydrophilic COOH-CNTs had stronger dispersion under aqueous electrolyte conditions, which could provide more reaction sites. Under certain hydrophobic conditions, non-polar force had cutoff effect on the diffusion of dissolved oxygen. The simulation results of electrolyte density showed good consistency with the experimental data, and the oxygen diffusion coefficient obtained was also consistent with the microscopic simulation results. This study was of great significance for the analysis of the mesoscopic morphology and mass transfer characteristics of the oxygen electrode during the charging and discharging process of lithium-oxygen battery.

Mechanistic Insights into the Voltammetric Determination of Riboflavin at Poly (Serine) Modified Graphite and Carbon Nanotube Composite Paste Electrode

AbstractIntense present work is directed on the fabrication and application of Poly (serine) modified graphite carbon nanotube composite paste electrode (PSR/CNTPE) for determining the Riboflavin (RF). The surface qualities of the projected sensor were observed by Field Emission Scanning Electron Microscopy (FE‐SEM) and the conductivity by Electrochemical Impedance Spectroscopy (EIS) method. The electrochemical redox activity of the PSR/CNTPE to RF was investigated through Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Outcomes displays that Poly (serine) in CNTPE enhanced the catalytic performance of the electrode towards the redox reaction of RF. The voltammetric response of PSR/CNTPE exhibited linear dependence for extended concentration range of RF from 6 μM to 50 μM with lower detection limit of 3.4×10−8 M.The PSR/CNTPE revealed to be reproducible, highly stable and successfully validated for the pharmaceutical, beverage and milk samples. The fabricated electrode was conducive and displayed two well‐separated oxidation signals for the solution containing two vitamins RF and Folic Acid (FA). The projected sensor is an adequate candidate for electrochemical sensing of RF.

Fabrication of Cu-WO3-functionalised multiwalled carbon nanotubes composite film electrode by direct deposition for sensing application

Development of nano composite film electrodes have been widely researched for its application as sensors, pseudo capacitors and negative electrodes. Different types of metal oxides, nano materials and various deposition techniques were concomitantly employed for fabrication of this type of electrodes. In the present work electroless deposition technique was applied for formation of copper seed layer over flexible poly ethylene substrate and further electrodeposition of WO3-functionalized multi walled carbon nanotube (fMWCNT) on to copper seed layer. Stable conducting films with uniform morphology of WO3-fMWCNT nano composite was formed over flexible copper substrate. The composite film possessed good electrochemical stability as revealed from various electrochemical analysis. The Cu-WO3-fMWCNT films were used as sensor for qualitative analysis of lubricant oils subjected to aging process under controlled conditions. The developed film electrode give good response curve in the impedance spectroscopy technique during the analysis of fresh and aged lubricant oil Different techniques such as X-ray Powder Diffraction, Scanning Electron Microscopy, Energy Dispersive X-Ray analysis with mapping pattern and Fourier Transform Infrared technique was used for characterization of the hybrid film electrode.

Three-dimensional bundle-like multiwalled carbon nanotubes composite for supercapacitor electrode application

Bundle-type mutil-walled carbon nanotubes (MWCNTs) composite electrode is the first investigation and publication for the supercapacitor application. According to the thermogravimetric analysis results, as-synthesized BCNTs are considered as the electrode materials for supercapacitors and electrochemical double-layer capacitor in this study. The Brunauer–Emmett–Teller specific surface area of as-prepared bundled carbon nanotubes (BCNTs) is 95.29 m2/g given to a type III isotherm and H3 hysteresis loops. Slow scanning rates promote and enhance to achieve high Cb because of the superior conductivity of CNT bundles and one side close-layered Ni/Mg/Mo alloy inside the BCNT-based electrode and facile electron diffusivity between electrolyte and electrode. The specific capacitance Cs (1,560 F/g) is nearly equal to the maximum specific capacitance, which the BCNT-based composite electrode can actually be able to charge or fill in. The maximum energy density value is 195 Wh/kg with corresponding power density values of 0.21 kW/kg. Furthermore, the active 3D BCNTs material fabricated electrode enhances to contact the electrolyte directly and decreases the ion diffusion limitation. Electrochemical impedance spectroscopy spectrum summarized as the low-frequency area controls by mass transfer limitation, and the high-frequency area dominates by charge transfer of kinetic control. After 2,000 consecutive cyclic voltammetry sacnings and galvanostatic charge-discharge cycles at a current density of 1.67 A/g performs, the specific capacitance retentions of 3D BCNTs electrodes achieved 128.2 and 77.3%, respectively. Three-dimensional BCNT composite electrodes exhibit good conductivity and low charge transfer resistance, which is beneficial to fast charge transfer between the BCNTs electrode materials and electrolytes.