Nitrogen-doped Multi-walled Carbon Nanotubes Research Articles

Crystalline multilayer graphene nanoflakes synthesized by catalytic chemical vapor deposition using reduced nanostructured hematite as catalyst precursor and 1,2-dichlorobenzene and benzylamine mixture as carbon source

Carbon solubility in the catalyst for the growth of graphene-type nanomaterials is an essential issue for their large-scale fabrication. Iron compounds are fundamental catalysts for the synthesis of carbon materials. The carbon solubility of ferrite (α-Fe) is ∼0.1% at 700 °C, which is enough to promote the growth of graphene nanomaterials. In this work, we synthesized crystalline multilayer graphene flakes (MLGFs) by a two-step catalytic chemical vapor deposition method using an α-Fe catalyst derived from the reduction of nanostructured hematite at 950 °C under an Ar–H2 environment. In the first step, nitrogen-doped multi-walled carbon nanotubes were synthesized by a benzylamine-ferrocene mixture at 850 °C and oxidized at 620 °C in air. In the second step, the reduced nanostructured hematite was exposed to a mixture of a 1:9 benzylamine-1,2- dichlorobenzene at 950 °C. Raman spectroscopy confirmed the presence of MLGFs with a G band and a significant 2D band intensity. The results of the thermogravimetric analysis show that the maximum oxidation rate was at 643.5 °C. Additional functional density calculations were performed considering graphene growth on the oriented (110) α-Fe surface. This work reasserts the possibility of using alternative carbon sources for graphene growth.

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.

Building a robust sulfur host for aqueous Cu-S battery by introducing nitrogen into carbon nanotubes

Aqueous metal-sulfur systems have become a research hotspot in recent years owing to their shuttle-free, great safety, and low cost. Among aqueous metal-sulfur systems, Cu-S battery is a big star for its huge theoretical capacity (3350 mAh g−1) based on a four-electron transfer reaction. Nevertheless, it faces the problem of poor cycle stability due to the poor conductivity of sulfur and its large volume expansion. In this study, we use nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) as an efficient host for loading sulfur, in which the introduction of nitrogen-containing groups into carbon not only increases the electronic conductivity of N-MWCNTs@S but also improves the adsorption behavior between N-MWCNTs and S/CuS/Cu2S. As a result, N-MWCNTs@S displays high reversible capacity, superior rate performance, and long-span cycling stability. When cycled at 1 A g−1, it can deliver a reversible capacity of 1580.1 mAh g−1 with 95.9% capacity retention after 454 cycles.

The synthesis of sponge-type nitrogen-doped multiwall carbon nanotubes using ball-milled natural red-leptosol as catalyst precursor: A cycle voltammetry study

Sponge-type nitrogen-doped multiwall carbon nanotubes (N-MWCNTs), synthesized via an aerosol-assisted catalytic chemical vapor deposition (AACCVD) method, were extensively studied. A ball-milled and oxidized red-leptosol (RL) was used as the catalyst precursor, and benzylamine worked as a carbon and nitrogen source. The ball-milled and oxidized RL increased their contact area and purity for the N-MWCNT synthesis. X-ray diffraction characterization revealed that raw RL contained kaolinite, quartz, graphite, hematite, and goethite. According to the electron microscopy analysis, the N-MWCNTs exhibited exotic morphologies and microstructures. The high-resolution X-ray photoelectron spectroscopy showed that the as-grown N-MWCNTs contained pyrrolic and pyridinic nitrogen species. The cyclic voltammetry studies demonstrated that the redox processes in the N-MWCNTs in 0.1 M H2SO4 were dominated by the carboxyl, pyridinic, and pyrrolic groups. Using the natural RL as a catalyst precursor in AACCVD led to a large yield of N-MWCNTs mixed with different minerals, causing the observed morphologies and influencing the electrochemical behavior, which is of interest in energy-storage and sensing applications.

Comparative study of nitrogen doped multi walled carbon nanotubes grafted with carboxy methyl cellulose hybrid composite by inverse gas chromatography and its UV photo detectors application

In this present work, the synthesis of nitrogen doped multi walled carbon nanotubes (N-MWCNTs) grafted Sodium-carboxy methyl cellulose (Na-CMC) hybrid composite was carried out via thermal reduction process. The hybrid composites were thermodynamically characterized by inverse gas chromatography (IGC) and compared to Na-CMC particles. The results were obtained by using 14 different IGC methods and models. We proved that the free energy of adsorption of the different solvents on N-MWCNTs-Na-CMC surface was equal to the summation of both free enthalpies of the solvents separately adsorbed on N-MWCNT and on Na-CMC surfaces. The London dispersive surface free energy of different materials was calculated by using the various molecular models. The more precise results were obtained by Hamieh model based on the effect of the temperature on the surface area of organic molecules. It was proved that the dispersive component of the surface energy of N-MWCNTs-Na-CMC was equal to the geometric mean than that of N-MWCNTs and Na-CMC surfaces. Lewis Acid base properties of the various materials were determined by using the different models and methods. A stronger basic character was highlighted for the different solid surfaces with more accentuated acid base character for N-MWCNT solid. Furthermore, the potential usage of the hybrid nanocomposite was studied for the practical application of the self-powered UV photodetection. On the other hand, the N-MWCNTs-Na-CMC hybrid heterostructure N-MWCNTs-Na-CMC exhibited excellent photoresponse characteristics with a good stability and reproducibility under the UV illumination (λ=382 nm) at zero bias. The high photoresponse performances were mainly attributed to the improved conductivity and enhanced charge transfer resulting from the synergetic effect of N-MWCNTs-Na-CMC hybrid heterostructure. The detailed photoresponse properties of the N-MWCNTs-Na-CMC hybrid heterostructure was discussed in detail using energy band theory.

The nitrogen-doped multi-walled carbon nanotubes modified membrane activated peroxymonosulfate for enhanced degradation of organics and membrane fouling mitigation in natural waters treatment

The synthesized catalyst nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) were introduced into membrane technology for peroxymonosulfate (PMS) activation. The enhanced permeability of the N-MWCNTs-modified membrane might be attributed to the increase in hydrophilicity and membrane porosity. The catalytic degradation and membrane filtration performance for the N-MWCNTs-modified membrane/PMS system in treating different types of natural waters were evaluated. The removal of phenol by the N-MWCNTs-modified membrane was 83.67% in 2 min, which was greater than the phenol removal by the virgin membrane (3.39%) and N-MWCNT powder (41.42%), respectively. Moreover, the resultant membrane coupled with PMS activation exhibited outstanding removal effects on the fluorescent organics in the secondary effluent and Songhua River water. The combination effectively reduced the total membrane fouling caused by the secondary effluent, Songhua River water, and three typical model organics by 28.19–61.98%. Electron paramagnetic resonance and classical quenching tests presented that the active species (SO4·−, ·OH, and 1O2) and other non-radical processes generated by N-MWCNTs activated PMS decreased the foulants deposition on the membrane surface. Meanwhile, the membrane interception accelerated the aggregation of pollutants and PMS towards the membrane surface through applied pressure, facilitating their mass transfer to the N-MWCNTs surface for the catalysis exerted more effectively. This study demonstrated the potential application of the coupling of N-MWCNTs catalytic oxidation and the UF, which offers a promising prospect to improve the permeate quality and simultaneously overcome the membrane fouling barriers.

Removal and surface photocatalytic degradation of methylene blue on carbon nanostructures

Removal and photodegradation of methylene blue on the surface of three distinct carbonaceous materials, pure and nitrogen-doped multi-walled carbon nanotubes, and graphitic nanoribbons, were examined. Carbon nanostructures were characterized by scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, Raman spectroscopy, X-ray photoelectron spectroscopy, and N2 adsorption/desorption isotherms. Removal and photocatalytic activity were evaluated by static adsorption under UV irradiation. Photocatalytic activity on carbon nanostructure exhibited a pseudo-first-order kinetic model. The adsorption capacity and photocatalytic activity of carbon nanostructures were mainly attributed to their defective and reactive surface. Nitrogen-doped multi-walled carbon nanotubes showed the best adsorption capacity and photocatalytic activity, which can be attributed to the highly reactive sites due to nitrogen doping, also by π–π electron donor-acceptor interaction between sp2 lattice of carbon nanostructure surface and negatively charged sites at methylene blue molecules.

Highly efficient solid-state synthesis of Co3O4 on multiwalled carbon nanotubes for supercapacitors

Synthesizing hybrid nanostructures through green protocols continues to attract great attention since it offers atom economy, simple processing, and environmental friendliness; and avoids using harsh chemical reagents. Herein we report the assembly of cobalt oxide on nitrogen-doped multiwalled carbon nanotubes (Co3O4-NMWCNT) composite synthesized by a green protocol with mechanochemical grinding for supercapacitor applications. The structural and morphological properties of the composites were confirmed by the aid of X-ray diffraction (XRD) studies, Raman spectroscopy, and scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HR-TEM). The synthesized composite material exhibited tube-like morphology with the distribution of Co3O4 nanoparticles. Fabricated Co3O4-NMWCNT symmetric supercapacitor device was further investigated for its electrochemical properties, thereby leading a high specific capacitance 202 F/g at 1 A/g of current density, with 25 Wh/kg of energy density at 0.9 kW/kg of power density. Therefore, Co3O4-NMWCNT composite electrodes offer excellent capacitive performance for the energy storage system.

Effect of pyrrolic-N defects on the capacitance and magnetization of nitrogen-doped multiwalled carbon nanotubes

Heteroatoms in multiwalled carbon nanotubes modify their chemical reactivity and electronic properties. Nitrogen as a doping element changes the morphology by boosting the surface area, the density of defects, electronic states, and chemically actives sites that improve the electrocatalytic activity and other properties. Nitrogen defects create mainly the pyridinic, pyrrolic, and quaternary-N configurations presenting different localized electronic configurations. This work outlined and studied the distribution and physicochemical properties of N-doped multiwalled carbon nanotubes as a function of the temperature profile along a CVD reactor. X-ray photoelectron spectroscopy demonstrated that the nitrogen content is maximal in the second furnace high-temperature zone, and the pyrrolic-N doping predominate. The ID/IG ratio from Raman spectroscopy increases in this zone, revealing a defective graphitic material. The cyclic voltammetry showed that the specific capacitance increases for pyrrolic-N from the last three-quarters of the reactor due to the augment of active carbon atoms associated with pyrrolic-N defects and the chemical decomposition of nitrogen precursor alongside the reactor. Theoretical calculation on the electronic properties and potential electrostatic surface of carbon nanotubes suggests the surface metallicity when pyridinic-N and quaternary-N are dominant and active sites for possible hydrogen or oxygen binding when pyrrolic-N are prevalent.

Ultrasonication-mediated nitrogen-doped multiwalled carbon nanotubes involving carboxy methylcellulose composite for solid-state supercapacitor applications

In this study, a novel nanohybrid composite containing nitrogen-doped multiwalled carbon nanotubes/carboxymethylcellulose (N-MWCNT/CMC) was synthesized for supercapacitor applications. The synthesized composite materials were subjected to an ultrasonication-mediated solvothermal hydrothermal reaction. The synthesized nanohybrid composite electrode material was characterized using analytical methods to confirm its structure and morphology. The electrochemical properties of the composite electrode were investigated using cyclic voltammetry (CV), galvanic charge–discharge, and electrochemical impedance spectroscopy (EIS) using a 3 M KOH electrolyte. The fabricated composite material exhibited unique electrochemical properties by delivering a maximum specific capacitance of approximately 274 F g−1 at a current density of 2 A g−1. The composite electrode displayed high cycling stability of 96% after 4000 cycles at 2 A g−1, indicating that it is favorable for supercapacitor applications.

Nitrogen-Doped Multiwalled Carbon Nanotubes Enhance Bone Remodeling through Immunomodulatory Functions.

It has been reported that multiwalled carbon nanotubes (MWCNTs) can reportedly positively affect growth and differentiation of bone-related cells and therefore offer great potential in biomedical applications. To overcome negative immune responses that limit their application, specific doping and functionalization can improve their biocompatibility. Here, we demonstrated that nitrogen-doped carboxylate-functionalized MWCNTs (N-MWCNTs) enhance bone remodeling both in vitro and in vivo with excellent biocompatibility, via stimulation of both bone resorption and formation. We revealed that 0.2 μg/mL N-MWCNTs not only increase the transcription of osteoblastogenic and osteoclastogenic genes but also up-regulate the activities of both TRAP and AKP in the differentiation of bone marrow stromal cells (BMSCs). Additionally, intramuscular administration of N-MWCNTs at a dosage of 1.0 mg/kg body weight enhances bone mineral density and bone mass content in mice, as well as induces potentiated degree of TRAP- and ARS-positive staining in the femur. The positive regulation of N-MWCNTs on bone remodeling is initiated by macrophage phagocytosis, which induces altered production of inflammatory cytokines by immune response pathways, and consequently up-regulates IL1α, IL10, and IL16. These cytokines collectively regulate the central osteoclastogenic transcription factor NFATc1 and osteoblastogenic BMP signaling, the suppression of which confirmed that these factors respectively participate in N-MWCNT-mediated regulation of osteoclastic and osteoblastic bone marrow stem cell activities. These results suggest that N-MWCNTs can be readily generalized for use as biomaterials in bone tissue engineering for metabolic bone disorders.

Preparation and Electrochemical Performance of V2O5 @N-CNT/S Composite Cathode Materials

Lithium–sulfur battery hasreceived widespread attention because of its high energy density, low cost, environmental friendliness, and nontoxicity. However, the insulating properties of elemental sulfur, huge volume changes, and dissolution of polysulfides in electrolytes that result in the shuttle effect, low sulfur utilization, and low rate performance seriously hinder the commercialization of lithium–sulfur batteries. In this work, a composite material of nitrogen-doped multiwalled carbon nanotubes and V2O5 was designed and fabricated to serve as the positive electrode of lithium–sulfur battery via the hydrothermal method. The positive electrode of the V2O5@N-CNTs composite material could reach an initial discharge specific capacity of 1,453 mAh g−1at a rate of 0.1C. Moreover, the composite material could maintain a discharge ratio of 538 mAh g−1 at a rate of 0.5C even after 200 charge and discharge cycles. After 400 cycles, the composite had a specific discharge capacity of 439 mAh g−1 at a rate of 1.0C. The excellent electrochemical performance of the V2O5@N-CNT/S composite cathode material was due to the fact that V2O5 contains oxygen ions and has a strong polarized surface. Furthermore, nitrogen doping changed the hybrid structure of carbon atoms and provided additional active sites, thereby improving the conductivity of the material itself and effectively inhibiting the dissolution and diffusion of polysulfides.

N-doped MWCNTs from catalyst-free, direct pyrolysis of commercial glue

We report a unique, catalyst-free, direct pyrolysis process to obtain nitrogen-doped multiwall carbon nanotubes (N-MWCNTs). The process includes the polymerization of ethyl cyanoacrylate (ECA) based commercial super glue with aqueous NaCl solution. The resultant poly-ethyl cyanoacrylate (PECA)-NaCl composite was washed to remove NaCl and subsequently calcined at 1000 °C in an inert atmosphere to obtain carbon nanotubes. The field emission scanning electron microscopy and high-resolution transmission electron microscopy studies confirm that these are nitrogen-doped multiwall carbon nanotubes (N-MWCNTs) with diameters in the range of 80–110 nm. Compared to conventional MWCNTs, these nanotubes exhibit distinct multilayer stacking of carbon with short-range ordering with interlayer spacing slightly larger than graphitic carbon. XPS studies reveal the presence of doped nitrogen substituting for carbon atoms, whereas Raman spectroscopy data shows that these nitrogen-doped nanotubes exhibit nanocrystalline, graphitic carbon. Washing of PECA-NaCl composite results in the removal of NaCl leading to the unique porous PECA intermediate structure. These unique morphological changes and structural transformations of PECA in DI water along with the peculiar degradation behavior of PECA during the heat treatment process may be responsible for the formation of N-MWCNTs.

Myeloperoxidase-induced degradation of N-doped carbon nanotubes: Revealing possible atomistic mechanisms underlying hypochlorite-driven damage of nanotube walls

We present a combined experimental and theoretical study dedicated to analyze the human myeloperoxidase (h-MPO)-catalyzed degradation of oxidized nitrogen-doped multi-walled carbon nanotubes (NMWCNTs-Ox) in vitro at 27 °C. NMWCNTs are synthesized by the aerosol assisted chemical vapor deposition (AACVD) technique and are characterized by employing transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), as well as Raman and X-ray photoelectron spectroscopies. H-MPO degradation, involving hypochlorous acid and hypochlorite species, leads to complete removal of CNTs with diameters smaller than 75 nm from the samples. Simultaneously, for larger sizes, it produces the formation of highly deformed NMWCNTs decorated with NaCl nanoparticles, which exhibit reduced cytotoxicity in exposed monocytes studies compared with the initial nanotube samples. Density functional theory (DFT) calculations performed on model nitrogen-doped CNTs are also presented to explore, at an atomistic level, the fundamental aspects underlying degradation. Our DFT results reveal that reactivity of carbon walls is significantly affected around N-doped pyridinic, pyrrolic, and substitutional sites, leading to the existence of HClO molecules physisorbed close to those defects and high local concentrations of chemisorbed ClO species on C atoms adjacent to the N-rich regions. The formation of these hypochlorite molecular islands on the nanotube surface facilitates ClO dissociation producing strongly bound O species and Cl atoms that can be carbon bonded or released into the environment. The previous surface reaction results in the cleavage of the underlying C–C bonds, creating holey regions on the graphitic walls. The continuation of this process would lead to the formation of larger holes on the nanotube surface, allowing, on the one hand, the permeation of ClO molecules to the internal layers and, on the other hand, producing a reduction of the NMWCNTs diameter as observed from our experimental data.

Mexican Natural Leptosol as Catalyst Precursor for Synthesis of Nitrogen-Doped Multiwall Carbon Nanotubes by Chemical Vapor Deposition

Mexican Natural Leptosol as Catalyst Precursor for Synthesis of Nitrogen-Doped Multiwall Carbon Nanotubes by Chemical Vapor Deposition

High-Performance Nanosilver Thin Film Nanocomposite Membranes Prepared on Carbon Nanotube-Based Supports

Biofouling in membranes is a serious concern as it leads to a severe reduction in membrane performance by increasing the membranes’ resistance to permeate flow. This work describes a facile method for the production of high performance nanosilver polyamide thin-film nanocomposite (TFN) membranes on carbon nanotube-based supports for biofouling control. The TFN membranes were prepared by the interfacial polymerization of a thin polyamide layer over a polyethersulfone (PES) support layer. Nanosilver (nAg) particles were generated in-situ on the surface of the polyamide layer using a reduction reaction between a silver salt and sodium borohydride. The support layer of the TFN membrane contained nitrogen doped multi-walled carbon nanotubes (N-MWCNTs) at various dosages. The SEM/EDS microscopic analyses revealed that nAg particles were present on the polyamide layer and that they were evenly distributed throughout the TFN membrane. Furthermore, the TFN membrane showed an improved water permeability (from 16.74 L/m2.h to 22.86 L/m2.h at 150 Psi) without sever compromise in NaCl rejection (from 98.37% to 99.40%) compared to the bare TFC membrane. This was attributable to the combined hydrophilic effects imparted by the presence of nAg on the TFN polyamide layer and the oxidised CNTs in the support layer. Antibacterial tests conducted using Escherichia coli bacteria demonstrated that the TFN containing nAg particles membranes exude better antibacterial activity compared to the pristine TFC membrane as evidenced by a clear zone of inhibition, in the area surrounding the TFN membrane and the absence of bacterial colonies. The present study demonstrated that the presence of low dosages of CNTs in the support layer is essential in the improvement of mechanical strength and performance properties of the support layer, while nAg plays a crucial role in the enhancement of TFN membrane performance.

Hybrid of NiO-Ni12P5/N-doped carbon nanotubes as non-noble electrocatalyst for efficient hydrogen evolution reaction

Nickel oxide and nickel phosphide supported by nitrogen-doped multi-walled carbon nanotubes (NiO-Ni12P5/NCNTs) nanocomposites were reported as non-noble metal hybrid electrocatalysts for hydrogen evolution reaction (HER). First, an amorphous nickel phosphorous coating was facilely formed on the surface of pristine CNTs (aNi-P/CNTs) through a simplified electroless deposition without the pretreatment steps of purification, sensitization and activation. Then, aNi-P/CNTs were heated with melamine at 600 °C for 1 h under an Ar atmosphere to prepare NiO-Ni12P5/NCNTs. The as-fabricated NiO-Ni12P5/NCNTs electrocatalysts showed high HER electrocatalytic activity of -0.17 V at 10 mA cm−2, a Tafel slope of 75 mV dec-1 and a high exchange current density of 0.049 mA cm-2. Moreover, the NiO-Ni12P5/NCNTs electrocatalysts showed a much higher durability than Pt/C after the accelerated durability tests in 0.1 M KOH. The NiO-Ni12P5/NCNTs electrocatalysts displayed good activity and stability for HER, which may originate from the synergistic effect between the Ni compound and NCNTs.

Directional Oxidation of Amine-Containing Phenolic Pharmaceuticals by Aqueous Dissolved Oxygen under Dark Conditions Catalyzed by Nitrogen-Doped Multiwall Carbon Nanotubes

As a widely used class of pharmaceuticals, amine-containing phenolic compounds are commonly found in water systems, which has raised growing concern about their potential health impact and requires...

FeCoCr alloy-nanoparticle embedded bamboo-type carbon nanotubes for non-linear optical limiting application

We demonstrate pyrolytic synthesis of nitrogen-doped multiwalled carbon nanotubes (NCNTs) incorporated with graphite-encapsulated FeCoCr alloy nanoparticles (FeCoCr@CN sample) and report their non-linear optical absorption (NLA) behaviour. The NCNTs present in the FeCoCr@CN sample were bamboo-type with box-shaped compartments. The improved electrical conduction in NCNTs, due to high degree of graphitization associated with optimum defect-concentration in the graphitic layer covering the FeCoCr-nanoparticles and nanotube structure, provides the non-linear absorption conditions required for their application in optical limiting devices. Our results emphasize the excellent optical limiting performance of our samples which originates mainly due to excited state absorption (ESA) and free carrier absorption (FCA) processes. The defect induced modification of the electronic properties of the graphitic carbon framework (due to nitrogen-doping) culminates the enhanced ESA of the laser beam. In addition, the choice of metallic FeCoCr-alloy nanoparticles provide two fold advantage in enhancing NLA: (i) it induces high graphitization on its surface than that expected due to the individual constituent metals, thereby enhancing the ESA effect, and (ii) being metallic, it leads to NLA via FCA. Our results highlight the superior NLA performance of our FeCoCr@CN sample, making it an excellent choice for its direct industrial use as laser shields.

Structure, functional composition and electrochemical properties of nitrogen-doped multi-walled carbon nanotubes synthesized using Co–Mo, Ni–Mo and Fe–Mo catalysts

We studied the effect of Co–Mo/MgO, Ni–Mo/MgO, and Fe–Mo/MgO catalysts on the structure and functional composition of nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) synthesized by chemical vapor deposition method. Polyoxomolybdates containing Co–Mo, Ni–Mo, Fe–Mo сores were used as the catalyst precursors and acetonitrile was the source of carbon and nitrogen for the growth of N-MWCNTs in argon atmosphere at 900 °C. The Ni–Mo/MgO catalyst promoted the formation of N-MWCNTs with the smallest outer diameter of 8 nm and the highest content of embedded nitrogen of 2.7 at.% with a predominance of pyridinic nitrogen form. Co–Mo/MgO and Fe–Mo/MgO catalysts yielded thicker N-MWCNTs with an average outer dimeters of 12 and 15 nm and lower nitrogen content of 2 and 1.5 at.%, respectively. N-MWCNTs were tested as electrodes in electrochemical capacitors and Li-ion batteries. A higher efficiency of the N-MWCNTs synthesized using Ni–Mo/MgO catalyst confirmed the advantage provided by a high content of nitrogen in the nanotube walls.