Carbon Carbon Nanotubes Research Articles

Performance Evaluation of Desalination Battery Systems based on Synthesis Method of Carbon Nanotube-Carbon Felt Composite Electrodes

To enhance chlorine ion removal and increase the current charging capacity of a desalination battery system, carbon nanotubes were applied to a carbonaceous electrode. Two types of composite electrodes were fabricated by attaching multiwalled carbon nanotubes (MWCNTs) to a carbon felt (CF) electrode via dip coating (D-CNT@CF) and electrophoresis (E-CNT@CF). These composite electrodes were then tested within a desalination battery system to evaluate their chlorine ion removal efficiency and current charging performance during the charging process. Microflocs of MWCNTs were observed on the surface of D-CNT@CF, whereas a uniform coating of MWCNTs was achieved on the surface of E-CNT@CF. Performance evaluations revealed that chlorine ion removal rates improved by 3.5% for D-CNT@CF and by 19.4% for E-CNT@CF compared to that of CF. Furthermore, the time required to reach maximum current charge was 40.0% for D-CNT@CF and E-CNT compared to CF. @CF decreased by 60.0%. These findings suggest that surface modification of carbonaceous electrodes through electrophoresis can result in a more stable coating and improve the performance of desalination battery systems.

Three-Dimensional random network of metacomposites by synergizing Multi-Walled carbon Nanotube-Carbon black for tunable Epsilon-Negative and Epsilon-Near-Zero responses

Epsilon-near-zero (ENZ) and epsilon-negative (EN) responses are remarkable properties of electromagnetic (EM) metamaterials that have sparked considerable interest. This paper introduces an innovative strategy using ternary metacomposites that achieve excellently tunable ENZ (|ε’| < 1) and EN (ε’ < 0) parameters within the radio-frequency band. The approach leverages a synergistic effect of multi-walled carbon nanotube-carbon black (MWCNT-CB) composites integrated into a polyaniline (PANI) matrix to construct three-dimensional (3D) carbon networks. As the loading content of MWCNT-CB increases, these networks evolve from clusters, enabling a finely tunable range of EN parameters from 100 to 103. The ENZ response occurs at approximately 265 MHz and 830 MHz, triggered by dielectric resonance due to electric dipoles at MWCNT-CB/PANI interfaces and a low-frequency plasmonic state in the 3D MWCNT-CB networks, respectively. This research establishes a foundation for tunable ENZ and EN responses by introducing a new class of ternary metacomposites.

Surface engineering of carbon nanotube-carbon fiber networks for enhanced strength in additive manufacturing of nylon composites

This work quantifies the impact of chemical functionalization of carbon nanotubes and carbon fibres on the interfacial shear strength, tensile and interlaminar shear strength properties of additively manufactured nylon composites. The surface chemistry of functionalized carbon materials was evaluated through infrared spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Single carbon fibre was dip-coated in a suspension of nanotubes and embedded into a nylon matrix. The fibres were pulled out to measure the interfacial shear strength, and the fibres with attached neat, carboxylated, and silanized nanotubes increased it by up to 67 %, 112 %, and 216 %, respectively. Composite samples were manufactured using a novel hybrid additive manufacturing method, which was able to deposit nylon layers and a suspension containing carbon reinforcement. The use of chemically functionalized nanotubes in the suspension led to carbon layers that improved tensile strength by 49 % and tensile modulus by 126 % over neat nylon. Functionalization of carbon reinforcement increased the interlaminar shear strength by up to 63 %. Overall, this paper demonstrates the importance of chemical modification in composite materials containing a large interface area of carbon materials.

Solution-Plasma Synthesis and Characterization of Transition Metals and N-Containing Carbon-Carbon Nanotube Composites.

Lithium-air batteries (LABs) have a theoretically high energy density. However, LABs have some issues, such as low energy efficiency, short life cycle, and high overpotential in charge-discharge cycles. To solve these issues electrocatalytic materials were developed for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which significantly affect battery performance. In this study, we aimed to synthesize electrocatalytic N-doped carbon-based composite materials with solution plasma (SP) using Co or Ni as electrodes from organic solvents containing cup-stacked carbon nanotubes (CSCNTs), iron (II) phthalocyanine (FePc), and N-nethyl-2-pyrrolidinone (NMP). The synthesized N-doped carbon-based composite materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). TEM observation and XPS measurements revealed that the synthesized carbon materials contained elemental N, Fe, and electrode-derived Co or Ni, leading to the successful synthesis of N-doped carbon-based composite materials. The electrocatalytic activity for ORR of the synthesized carbon-based composite materials was also evaluated using electrochemical measurements. The electrochemical measurements demonstrated that the electrocatalytic performance for ORR of N-doped carbon-based composite material including Fe and Co showed superiority to that of N-doped carbon-based composite material including Fe and Ni. The difference in the electrocatalytic performance for ORR is discussed regarding the difference in the specific surface area and the presence ratio of chemical bonding species.

Synergistic advancements in sewage-driven microbial fuel cells: novel carbon nanotube cathodes and biomass-derived anodes for efficient renewable energy generation and wastewater treatment

Microbial fuel cells (MFCs) offer a dual solution of generating electrical energy from organic pollutants-laden wastewater while treating it. This study focuses on enhancing MFC performance through innovative electrode design. Three-dimensional (3D) anodes, created from corncobs and mango seeds via controlled graphitization, achieved remarkable power densities. The newly developed electrode configurations were evaluated within sewage wastewater-driven MFCs without the introduction of external microorganisms or prior treatment of the wastewater. At 1,000°C and 1,100°C graphitization temperatures, corncob and mango seed anodes produced 1,963 and 2,171 mW/m2, respectively, nearly 20 times higher than conventional carbon cloth and paper anodes. An advanced cathode composed of an activated carbon-carbon nanotube composite was introduced, rivaling expensive platinum-based cathodes. By optimizing the thermal treatment temperature and carbon nanotube content of the proposed cathode, comparable or superior performance to standard Pt/C commercial cathodes was achieved. Specifically, MFCs assembled with corncob anode with the proposed and standard Pt/C cathodes reached power densities of 1,963.1 and 2,178.6 mW/m2, respectively. Similarly, when utilizing graphitized mango seeds at 1,100°C, power densities of 2,171 and 2,151 mW/m2 were achieved for the new and standard cathodes, respectively. Furthermore, in continuous operation with a flow rate of 2 L/h, impressive chemical oxygen demand (COD) removal rates of 77% and 85% were achieved with corncob and mango seed anodes, respectively. This work highlights the significance of electrode design for enhancing MFC efficiency in electricity generation and wastewater treatment.

Electrical and microstructural characterization of carbon nanotube-carbon fiber added cementitious conductive surface coating

In contrast to the traditional methods of directly adding conductive fillers to the cement matrix in the development of heatable conductive concrete, radiation shielding and smart sensing cementitious materials, this study proposes a more efficient approach by covering the non-conductive glass fiber reinforced concrete (GRC) surface with a thin conductive layer. Single-walled carbon fiber (SWCNT) and carbon fiber (CF) were used as conductive additives in the mixture of electrically conductive surface coating. Dosages of 0.1%, 0.2%, and 0.3% (wt) for SWCNT and 0.2%, 0.4%, 0.6%, 0.8%, and 1% (Vol) for CF were preferred. According to these ratios, a total of 15 different conductive cement coatings were carried out. White Portland cement and fine silica sand were used as binder and filler material, respectively. The conductive cement-based coating with a thickness of approximately 3 mm shows good adhesion and integration properties, since it is placed in the mold gradually at the same time as the GRC, which acts as the substrate. Resistivity, impedance, heatability (electrothermal), TGA-DTA and microstructure characterization were performed to investigate the electrical, thermal and microstructural properties of the coatings.The impedance/resistance properties of the cement-based composite samples containing CF showed superior performance compared to the other samples. In TGA/DTA analyses, the amount of CF in the cement mixture did not affect the thermal weightlossmuch. The lowest resistivity values were measured as 20 and 80 Ω.cm for the CF1.0 and CF0.8 samples, respectively, and the electrothermal test results showed that the temperature reached 45.5 and 28 °C from 23 °C, respectively, by applying 24 V voltage within 1 h with a power consumption of 750 W/m2 and 232 W/m2.

Carbon nanotube-carbon black/CaCu3Ti4O12 ternary metacomposites with tunable negative permittivity and thermal conductivity fabricated by spark plasma sintering

Carbon nanotube-carbon black/CaCu3Ti4O12 ternary metacomposites with tunable negative permittivity and thermal conductivity fabricated by spark plasma sintering

The study of Letrozole adsorption upon CCT nanotube: A DFT/TD-DFT and spectroscopic (excited states and UV/Vis)

In this research, the geometric structure of LTZ and CCT (5,0) was optimized with B3LYP/6-31G* method using the Gaussian 09W program package to investigate the weak interaction of Letrozole (LTZ) and carbon carbon nanotube (CCT). According to the calculation of the release energy, it was found that the drug delivery process is desirable. Also, the structural properties of the title compounds were assessed by thermodynamic and frontier molecular orbital (FMO) parameters. In this study, a series of measures have been performed to detect changes in drug loading properties and non-bonding interactions between the LTZ and CCT (5,0) nanotube. The non-bonding interaction effects of LTZ and CCT over the electronic properties were also evaluated and argued. The research is based on the fact that studies can help to understand the interaction between the LTZ drug and CCT (5,0) nanotube and the development of CCT-based drug release systems. This research aimed to determine variations in electronic properties of anticancer LTZ drug in presences CCT. Then, the reactivity and stability behavior of LTZ drug and on CCT to be examined by density functional theory (DFT). Then, frontier molecular orbital (FMO) and noncovalent interaction (NCI) analyses were performed, which decrease in reactivity described increase in the stability of LTZ drug.

Strengthening and toughening behaviors and dynamic constitutive model of carbon-based hierarchical fiber modified concrete: Cross-scale synergistic effects of carbon nanotubes and carbon fiber

Considering the synergistic effects (filling, activating, bridging, anti-cracking, and interface-optimizing) of combined carbon fiber and carbon nanotubes, the strategy of using carbon nanotubes-carbon fiber cross-scale reinforcement (CNTs-CF) to enhance concrete was proposed. The strengthening and toughening behaviors of CNTs-CF modified concrete (CCMC) were experimentally investigated. The results showed that CCMC had good crushing resistance capacity, and the addition of an appropriate amount of CNTs-CF was conducive to alleviating the brittle failure characteristics of concrete materials. Compared with ordinary concrete, the static and dynamic strength properties and toughness indexes of CCMC were greatly improved. When the volume content of CNTs-CF in concrete was 0.3%, CCMC showed the most superior strengthening and toughening behaviors. The hierarchical assembly and synergistic effect of carbon fiber and carbon nanotubes realized the combination of high strength and high toughness of concrete materials. The proposed rate-dependent constitutive model with damage based on Weibull statistical theory in this study can be used to accurately predict the dynamic compressive stress-strain relationship curve of concrete under different fiber content and strain rate.

Interfacial solar steam generator by MWCNTs/carbon black nanoparticles coated wood

In order to further improve the efficiency of radiation steam generation and the stability in practical application, multi-walled carbon nanotubes (MWCNTs)/carbon black nanoparticles were used to coat the delignified wood cross section. The results showed that the multi-walled carbon nanotubes and carbon black nanoparticles are cross-linked and uniformly attached to the cross section of wood, forming a relatively rough coating. Through comparative experiments, the sample device displayed a favorable effect of radiation evaporation, with a 24-hour evaporation efficiency of 51.1%, which was 8.9%, 13.0% and 8.4% higher than that of natural wood device, delignified wood device and natural wood device coated with multi-walled carbon nanotubes-carbon black mixed solution, respectively. On the one hand, it benefited from the high broadband absorption efficiency of multi-walled carbon nanotubes-carbon black coating, which exhibited an absorption efficiency of ∼97.5% and an extremely low transmittance of <2.5% in the visible light and ultraviolet region, and on the other hand, it benefited from the unique surface nanostructure of multi-walled carbon nanotubes-carbon black surface coating, which could effectively capture light.

Double-phase 1T/2H–MoS2 heterostructure loaded in N-doped carbon/CNT complex carbon for efficient and rapid lithium storage

MoS2 has been considered as a potential anode for lithium-ion batteries. Most of the lab-prepared MoS2 anode materials are 2H phase with low intrinsic conductivity. To compensate the intrinsic low conductivity of 2H–MoS2 and its structural instability in cycles, a N-doped carbon-carbon nanotube (NC-CNT) carbon complex is prepared as the basic structure for MoS2 growth, and a 1T/2H–MoS2 heterostructure is fabricated on this structure. On one hand, CNTs create additional pores and connect isolated sheets of the NC, which provides enough inner growth space for MoS2 and maintains the overall electrical conductivity. On the other hand, the double-phase 1T/2H–MoS2 with high content (60%) of the metallic 1T-MoS2 gives a larger layer spacing, higher internal electron conductivity, and more active lithiation and de-lithiation reactions. To serve as anode for lithium-ion batteries, the synthesized 1T/2H–MoS2@NC–CNT has a reversible capacity of 764.99 mAh g−1 at 200 mA g−1 and an high-rate capacity of 547.7 mAh g−1 at 1000 mA g−1 even after 1000 cycles. By studying the reaction kinetics, impedance and lithiation/delithiation mechanism during electrochemical reactions, it is concluded that 1T/2H–MoS2@NC–CNT obtains declined charge transfer resistance, accelerated diffusion of Li+, improved cyclic stability, and enhanced structure/property reversibility from the carbon complex and the high-content 1T phase MoS2.

Broadband electromagnetic shielding performance of carbon nanotube-carbon fibre/silicon carbide cross-scale laminated composites

A carbon nanotube-carbon fibre/silicon carbide (CNT-CF/SiC) laminated composite, with a density of 1.61 g/cm3, thickness of 2.7–3.0 mm and conductivity of 6.10 S/cm, was prepared by densifying a single layer with boron-modified phenolic resin and then welding it with resin-derived carbon layer by layer. This laminated composite was alternately composed of a relatively dense CNT buckypaper/SiC composite layer and a relatively porous three-dimensional needled CF felt/SiC composite layer. The CF felt with a laminated constructure produced a laminated substructure nested within the layers. Expanded graphite with laminated structures produced laminated substructures nested within the interfaces. The average total shielding efficiency values of the composites with 5 layers (CNT-CF/SiC-5), 4 layers and a CNT buckypaper/SiC composite layer on the top surface, and 4 layers and a CF felt/SiC composite layer on the top surface were 45.14, 37.70 and 38.85 dB, respectively, throughout the X-band and were 52.31, 45.56 and 43.54 dB, respectively, throughout the Ku-band. The transmission coefficient of CNT-CF/SiC-5 was as low as 10−5−10−6 orders of magnitude over the entire frequency range of 8.2–18 GHz except for very few frequency points. The optimal number of layers for this multilevel and multiscale laminated composite is believed to be 5.

A novel hybrid carbon materials-modified electrochemical sensor used for detection of gallic acid

Novel hybrid carbon materials such as activated carbon-carbon nanotubes (AC-CNTs) and carbon spheres/activated carbon-carbon nanotubes (CSs/AC-CNTs) based on activated carbon (AC) derived from the pits of Algerian date palm have been prepared and characterized. In addition, the carbon paste electrodes based on graphite carbon (GC) and cavity microelectrode (CME) modified with these hybrid materials were used to detect gallic acid at pH = 7 using square wave voltammetry method (SWV). The conductivity measurements revealed that CSs/AC-CNTs is more conducting than AC-CNTs. SWV measurements showed that the oxidation current was directly proportional to the concentrations of gallic acid (from 0 to 0.00536 M) with the lowest limit of detection (LOD), reaching 6.43 µM and 3.64 µM using GC/CSs/AC-CNTs electrode and CME/GC/CSs/AC-CNTs sensor, respectively. The reproducibility and the stability of the studied sensor were confirmed by the relative standard deviation of the oxidation current response of gallic acid (RSD Reproducibility = 1.44% and RSD Stability = 3.7%).

Enhanced capacitance of manganese oxide driven by hierarchically structured carbon nanotube-carbon nanowall composite

The deposition of transition metal oxides on hierarchically grown carbon‑carbon nanostructures improves the storage properties of electrode materials for next-generation energy storage devices. Usually, a thin layer of oxide covering the carbon nanostructure is deposited to avoid high series resistance values. However, increasing the energy storage density of the electrode requires the deposition of a larger amount of electrochemically active material. Here we demonstrate the improvement in performance of the metal oxide layer when hierarchically grown carbon‑carbon nanostructures are present on the substrate. Optimum capacitance, series resistance, and cycling stability are found to be after 20 min manganese oxide electrodeposition time on carbon‑carbon nanocomposites. The asymmetrical supercapacitor devices prepared under these conditions present high energy density (2.9 mWh·cm−2), moderate power density (2.8 mW·cm−2), and high cycling stability (80% capacitance retention after 20,000 cycles).

Carbon nanotube-carbon black hybrid counter electrodes for dye-sensitized solar cells and the effect on charge transfer kinetics

In this work, the catalytic activity of carbon nanotubes (CNTs), carbon black (CB), and CNT-CB counter electrodes in the I−/I3− reduction reaction is reported and compared with the Pt counter electrode. The fabricated counter electrodes were evaluated in dye-sensitized solar cells (DSSCs). The results indicate that the best cathodes were made from CNT10 (240 μm) and CB with a charge transfer resistance (RCT) of 2.70 Ω, and when the complete device shows 19.83 Ω of internal series resistance (RS), the photovoltaic parameters of these cells were JSC = 10.47 mA cm−2; VOC = 0.70 V; and FF = 57.90, with an efficiency of 4.29%, indicating a better interaction between the CNT10 in the 3D network of the counter electrode, generating a good charge transfer kinetics, in comparison with only CNT10 or CB.

Communication—Modulation Mechanism of Epsilon-Negative and Epsilon-Near-Zero Behavior in Carbon Nanotube-Carbon Black/Copper Calcium Titanate Ternary Metacomposites

Carbon nanotube-carbon black (CNT-CB) regarded as the combined functional fillers were randomly distributed in copper calcium titanate (CCTO) and went through three stages, i.e., isolated, partially clustered and totally networked morphologies with increasing the content. A transition of permittivity from positive to negative was interestingly obtained. Meanwhile, in the vicinity of transition, the permittivity was close to zero and epsilon-near-zero (ENZ) behavior was achieved. The negative permittivity was attributed to combined action of plasma oscillation of electrons and dipole resonance. Further investigation manifested that epsilon-negative behavior correlated with inductive character.

Carbon Nanomaterials for Biomedical Application.

The use of carbon-based nanomaterials (CNs) with outstanding properties has been rising in many scientific and industrial application fields. These CNs represent a tunable alternative for applications with biomolecules, which allow interactions in either covalent or noncovalent way. Diverse carbon-derived nanomaterial family exhibits unique features and has been widely exploited in various biomedical applications, including biosensing, diagnosis, cancer therapy, drug delivery, and tissue engineering. In this chapter, we aim to present an overview of CNs with a particular interest in intrinsic structural, electronic, and chemical properties. In particular, the detailed properties and features of CNs and its derivatives, including carbon nanotube (CNT), graphene, graphene oxide (GO), and reduced GO (rGO) are summarized. The interesting biomedical applications are also reviewed in order to offer an overview of the possible fields for scientific and industrial applications of CNs.

ZIF-8@ZIF-67–derived ZnCo2O4@nitrogen–doped carbon/carbon nanotubes wrapped by a carbon layer: a stable oxygen reduction catalyst with a competitive strength in acid media

Owing to the sluggish reaction kinetics and poor stability of cathodic catalysts for oxygen reduction reaction (ORR) in acidic media, the development of highly active and acid-stable ORR catalysts is of great practical significance. Herein, the prepared ZIF-8@ZIF-67 material, polyvinylpyrrolidone (PVP), and expanded graphite (EG) are used as precursors to prepare the ZnCo2O4@nitrogen-doped carbon-carbon nanotubes wrapped by a PVP-derived thin carbon layer anchored on the EG (ZnCo2O4@NC-CNTs@PCL/EG) as ORR catalysts. ZnCo2O4@NC-CNTs@PCL/EG-10 (weight ratio of ZIF-8@ZIF-67 to EG = 10) has an onset potential of 0.689 V (vs. SCE), which is comparable with that of commercial Pt/C (0.706 V) in the acid electrolyte. After acid pickling, the spinel ZnCo2O4 as the core is stably and uniformly encapsulated by the NC-CNT skeleton and can fully use the highly active Co2+ sites to boost the 4e– ORR process with a strong methanol resistance. ZnCo2O4@NC-CNTs@PCL/EG-10 shows strong stability and methanol tolerance (a decline of 3.21%) after 3600 s, which are better than those of commercial Pt/C (29 mV and 4.06%). The ORR durability is attributed to the PCL shell that avoids the corrosion of active ZnCo2O4 and N-species. Therefore, it provides a new idea for designing a spinel-based ZIF derivative as stable ORR catalysts in acid media.

Superior lithium-ion storage performance of hierarchical tin disulfide and carbon nanotube-carbon cloth composites

Tin-based composites are promising anode materials for high-performance lithium-ion batteries (LIBs); however, insufficient conductivity, as well as fatal volume expansion during cycling lead to poor electrochemical reversibility and cycling stability. In this work, we demonstrate the lithium-ion storage behaviors of SnS2 anode material deposited on different electrode supports. The SnS2 grown on 3D hierarchical carbon nanotube-carbon cloth composites (SnS2-CNT-CC) shows superior capacity retention and cycle stability, compared to that on planar Mo sheets and carbon cloth. The specific capacity of SnS2 on Mo, CC, and CNT-CC is around 240, 840, and 1250 g−1, respectively. The SnS2-CNT-CC electrode outperforms in the cyclic performance and rate capability compared to other electrode configurations due to the multi-electron pathway and high surface area derived from 3D hierarchical CNT-CC electrode support. Furthermore, a significant decrease in the charge transfer resistance is observed by utilizing 3D hierarchical CNT-CC electrode support. The use of 3D hierarchical structures as electrode support could be the best alternative to enhance the electrochemical performances for the next generation LIBs.

Enhanced Catalytic Conversion of Polysulfides Using Bimetallic Co7Fe3 for High-Performance Lithium-Sulfur Batteries.

Practical applications of lithium-sulfur (Li-S) batteries have been severely hindered by their low capacity, poor rate performance, and fast capacity degradation, which mainly originate from the notorious polysulfide shuttle effect. Herein, with density functional theory calculations, we show that the alloying of Fe into carbon-coated Co not only provides moderate binding interactions with the polysulfides to hinder their diffusion but also serves as an active catalyst in the spontaneous and successive lithiation of S8 to Li2S. Based on the fast migration of Li ions and the spontaneous lithiation of Li2S2 on the carbon-coated Fe-Co alloy, the entrapping-conversion processes of polysulfides are both thermodynamically and kinetically promoted in redox cycling. Experimentally, rationally designed Co7Fe3@porous graphite carbon-carbon nanotubes (Co7Fe3@PGC-CNT) electrocatalysts are introduced into Li-S batteries through separator functionalization. Consistent with theoretical predictions, Li-S batteries with Co7Fe3@PGC-CNT modified separators exhibit a dramatically enhanced rate capacity (788 and 631 mAh g-1 at 10 and 15 C rates, respectively) and cycling stability (a slow capacity decay of 0.05% per cycle over 1000 cycles at 2.0 C), which are superior to those of most reported Li-S batteries coupled with state-of-the-art separators. Furthermore, it is shown that the excellent hindering of the shuttle effects enables a high areal capacity of 4.7 mAh cm-2 after 90 cycles at a high sulfur loading of 6.7 mg cm-2. Our work provides a feasible method for developing high-energy and long-life Li-S batteries, which might drive the commercialization of Li-S batteries.