Nitrogen-doped Carbon Nanorods Research Articles

Selective electrosynthesis of ammonia via nitric oxide electroreduction catalyzed by copper nanowires infused in nitrogen-doped carbon nanorods

The electrochemical nitric oxide reduction reaction (eNORR) is meticulously investigated as an alternative to the energy intensive Haber-Bosch process to produce Ammonia (NH3). However, the eNORR is hindered by NH3 selectivity due to side reactions and mass-transfer limitations. In this work, we rationally designed copper nanowires (Cu NWs) infused in the lotus-root-like multi-nano-channels of the porous N-doped carbon nanorods (Cu-mNCNR) for a high selective eNORR to synthesize NH3 at ambient conditions. The optimized catalyst, Cu-mNCNR2, has achieved the highest NH3 Faradaic efficiency of 79% with NH3 yield rate of 34.5 μmol cm–2 h–1 at −0.4 VRHE. Moreover, the Cu-mNCNR2 has demonstrated a vigorous performance in the 24 h continuous NO electrolysis to produce NH3. Additionally, a prototype device, the Zn-NO battery, was demonstrated. This study shows that the rational design of a catalyst considering mass-transfer limitations is crucial to achieving high selective NH3 electrosynthesis in eNORR.

Nitrogen-doped carbon nanorods embedded with cobalt nanoparticles as separator coatings for high-performance lithium-sulfur batteries

Nitrogen-doped carbon nanorods embedded with cobalt nanoparticles as separator coatings for high-performance lithium-sulfur batteries

Efficient hydrogen evolution enabled by in-situ synthesis of biphasic Mo2C/Mo16N7 nitrogen-doped carbon nanorods as catalysts

Molybdenum carbide (Mo2C) has gained significant recognition as a cutting-edge, non-precious transition metal catalysts for efficiently driving the hydrogen evolution reaction (HER). However, the desorption of Mo-H bonds on the pristine Mo2C surface are difficult, resulting in a slow Heyrovsky/Tafel step. Herein, biphasic Mo2C/Mo16N7 nitrogen doped carbon nanorods (Mo2C/Mo16N7@NRs) is synthesized as the high-performance HER electrocatalyst by using a one-step in-situ pyrolysis growth method. It is found that a suitable pyrolysis temperature can simultaneously tune the morphology of the catalyst and form abundant heterointerface. Benefit from abundant porous nanostructure and more electron-rich Mo active sites at the Mo2C-Mo16N7 interfaces, the optimized Mo2C/Mo16N7@NRs demonstrates exceptional catalytic activity. It achieves low overpotentials (η10) of 63.62 and 117.43 mV at 10 mA cm−2, accompanied by Tafel scopes of 49.73 and 64.44 mV dec−1 in both alkaline and acidic electrolytes. Also, Mo2C/Mo16N7@NRs shows long-lasting stability for 24 h in the different electrolytes. The experimental and theoretical findings explain the synergistic effects of unique morphology control and interface engineering on electrocatalyst activity. The one-step in-situ pyrolysis growth method is expected to produce non-precious metal catalysts with distinct morphology and heterointerfaces.

Boronization of ZIF-67 on nickel foam to prepare self-supporting NiCo-bimetallic borides electrocatalyst for efficient oxygen evolution reaction

The research and development of self-supporting transition metal catalysts are of great significance to the practical application of water splitting. Among these, transition metal boride exhibits high catalytic activity and exceptional stability. In this study, a large specific surface area structure (SSAS) of ZIF-67 nanorods grown on nickel foam (NF) was constructed, which reacted with boron carbide (B4C) to prepare a self-supporting NiCo-bimetallic boride loading on nitrogen-doped carbon nanorods (NixB-Co4B@NC/NF-800) for efficient oxygen evolution reaction (OER). The SSAS of NixB-Co4B@NC/NF-800 catalyst enhanced the exposure of active edge sites. Meanwhile, the connection between bimetallic boride and doped carbon could promote charge transfer. And the structure of nanorods modified with nanosheets contributed to the transmission and release of bubbles on the catalyst surface during electrolysis. The synergistic effect of bimetallic borides facilitated to reduce the reaction barrier and accelerate the OER reaction. The NixB-Co4B@NC/NF-800 required an overpotential of 247 and 296 mV to achieve 10 and 50 mA cm−2, respectively, which is on a par with IrO2/C. In addition, due to its unique structure (nanorods modified with nanosheets), the NixB-Co4B@NC/NF-800 also showed excellent electrochemical stability.

MOF-derived porous NiCo2S4 nanocrystals embedded in nitrogen-doped carbon nanorods as lithium battery anodes

MOF-derived porous NiCo2S4 nanocrystals embedded in nitrogen-doped carbon nanorods as lithium battery anodes

Transition Metal Nanoparticle-Embedded Nitrogen-Doped Carbon Nanorods as an Efficient Electrocatalyst for Selective Electroreduction of Nitric Oxide to Ammonia

Transition Metal Nanoparticle-Embedded Nitrogen-Doped Carbon Nanorods as an Efficient Electrocatalyst for Selective Electroreduction of Nitric Oxide to Ammonia

N-Doped Carbon Nanorods from Biomass as a Potential Antidiabetic Nanomedicine.

Insufficient glucose control remains a critical challenge for type 2 diabetes mellitus (T2DM) patients with currently used therapeutic drugs, which can also have detrimental side effects. The facile synthesis of nitrogen-doped carbon nanorods (N-CNRs) as therapeutic agents in a T2DM transgenic db/db mouse model is reported herein. N-CNRs are synthesized from silkworm powder without the assistance of any template and possess a hollow graphitic nature, rough surface, and good aqueous solubility, which make them ideal candidates for fabricating nanomedicines. N-CNRs are employed to reduce fasting blood glucose and ameliorate serum biomarker levels linked to oxidative stress and inflammation. Interestingly, through the downregulation of enhanced expression of glutathione peroxidase, superoxide dismutase, and catalase as well as inflammatory responses, N-CNRs reverse pancreatic dysfunction and normalize the secretory functions of pancreatic cells. Moreover, hepatic steatosis is attenuated by downregulating lipogenesis and increasing fatty acid oxidation. This finding may help in designing novel therapeutics for T2DM treatment.

Accelerated N2 reduction kinetics in hybrid interfaces of NbTiO4 and nitrogen-doped carbon nanorod via synergistic electronic coupling effect

Electrochemical ammonia synthesis through the atmospheric nitrogen reduction reaction (NRR) is a promising method for sustainable fertilizer and carbon-free hydrogen energy carriers. The inevitable selectivity gap against hydrogen evolution reaction and inert nitrogen (N2) hinders the device-level usage of nitrogen cathodes. In this work, we report engineered electrocatalyst/support interface of NbTiO4 nanoparticles supported on nitrogen-doped carbon nanorods (NbTiO4@NCNR) to catalyze NRR. Insisted by the pitfalls to rationally design N2 reduction catalysts, the strong catalyst-support interaction strategy is adapted to tune the selectivity towards NRR. Electrochemical tests reveal that NbTiO4@NCNR hybrid accelerates a 10-fold increase in N2 selectivity compared to pure metal oxide. Using first-principles calculations, we identify the underlying mechanism of enhanced performance: bridging bonds in the interface as electron transport channels to promote the N2 reduction kinetics. Essentially, this study provides an insight into how to overcome the immense kinetic barrier of NRR using smartly engineered interfaces of hybrid materials.

Ni3N nanoparticles on porous nitrogen-doped carbon nanorods for nitrate electroreduction

Electrocatalytic nitrate reduction into recyclable ammonium under mild conditions provides an efficient and clean ammonium production strategy and remediation of nitrate-containing wastewater. In this work, we successfully synthesize the Ni3N nanoparticles anchored on nitrogen-doped carbon (Ni3N/N-C) nanohybrids through simple calcination and acid etching procedures using Ni-dimethylglyoxime complex (Ni-DMG) nanorods as raw material. Physical characterizations confirm that as-synthesized Ni3N/N-C nanohybrids have the high specific surface area of 665.7 m2 g−1 and the ultrafine Ni3N nanoparticles (5.3 nm) are dispersed uniformly on the surface of porous nitrogen-doped carbon nanorods. The electrochemical experiments indicate that the combination of nitrogen-doped carbon can greatly improve electroactivity of Ni3N nanoparticles for nitrate reduction reaction. Consequently, Ni3N/N-C nanohybrids possess high selectivity for ammonium production (89.5%) and high yield rate of ammonium (9.185 mmol h−1 mgNi3N−1) for nitrate electroreduction. Additionally, Ni3N/N-C nanohybrids also show excellent long-term stability due to their structural/chemical stability.

Bimetal–organic frameworks derived tuneable Co nanoparticles embedded in porous nitrogen-doped carbon nanorods as high-performance electromagnetic wave absorption materials

Bimetal-organic frameworks derived tuneable Co nanoparticles embedded in porous nitrogen-doped carbon nanorods for electromagnetic wave absorption applications.

Green Synthesis of a Highly Efficient and Stable Single-Atom Iron Catalyst Anchored on Nitrogen-Doped Carbon Nanorods for the Oxygen Reduction Reaction

The synthesis of inexpensive and efficient electrocatalysts with an excellent stability for the electrochemical oxygen reduction reaction (ORR) in both alkaline and acid media through a facile environment-friendly strategy is extremely desirable but remains challenging. In this study, a single-atom iron electrocatalyst with exclusively Fe–N₄ moieties anchored on nitrogen-doped carbon nanorods (denoted as Fe–SA/NCS) is synthesized through a one-step pyrolysis of Fe-doped zeolitic imidazole framework-8 (ZIF8) nanorods that are synthesized in an aqueous system without acid leaching assistance. Profiting from the synergistic effect of the hierarchically porous carbon support with a rodlike structure and the large number of Fe–N₄ moieties, the newly prepared Fe–SA/NCS exhibits excellent ORR catalysis activities with a half-wave potential of 0.91 V vs RHE in 0.1 M KOH as well as 0.77 V vs RHE in 0.1 M HClO₄. Furthermore, better stability in alkaline or acid conditions was also observed for Fe–SA/NCS compared with Pt/C. The high open-circuit voltage of 1.53 V and high power density of 141.6 mW cm–² of a zinc–air battery (ZAB) with Fe–SA/NCS as the cathode material indicate excellent electrochemical performances. The ZAB with the Fe–SA/NCS catalysts exhibits a remarkable cycling performance for more than 300 h with a high voltaic efficiency of 78.6%. The present work could pave the way for the rational construction of highly efficient and stable single-atom electrocatalysts through green synthesis for sustainable energy technologies.

Fe, Mo–N/C Hollow Porous Nitrogen-Doped Carbon Nanorods as an Effective Electrocatalyst for N2 Reduction Reaction

The development of highly active, non-noble metal-based materials for electrocatalytic nitrogen reduction reaction (NRR) under environmental conditions is still a challenge. Herein, we have designe...

Hierarchical oxygen rich-carbon nanorods: Efficient and durable electrode for all-vanadium redox flow batteries

We describe the fabrication of hierarchical oxygen and nitrogen enriched-carbon electrode materials from zein and polyacrylonitrile by a simple electrospinning technique for durable and high rate all-vanadium redox flow batteries (VRBs). The nitrogen-doped carbon nanorods (NCNR) provide abundant oxygen-rich and nitrogen active sites, and thereby, enhancing the catalytic activity toward both VO2+/VO2+ and V2+/V3+ ion redox reactions by improving ion transfer kinetics and faster electron transfer rate in VRB. With improving electrocatalytic properties, the NCNR decorating carbon felt electrode (NCNR/CF) exhibits excellent battery performance with an impressive specific capacity of 37.3 Ah L−1 than pristine CF (22.8 Ah L−1) and CNR/CF (28.6 Ah L−1) electrodes. The NCNR/CF electrode also shows an outstanding coulombic efficiency (CE, 98.9%) and energy efficiency (EE, 84.3%) compared with the pristine CF (CE, 91.2% and EE, 73.4%) and the CNR/CF (CE, 95.6% and EE, 81.2%) electrodes in the VRB at 40 mA cm−2 current density. Furthermore, the NCNR/CF electrode exhibits 10.9 and 3.1% higher EE as compared to the pristine CF and CNR/CF electrodes, respectively. Therefore, the impressive cyclic rate capability with negligible capacity decay proves the superiority of NCNR as a potential electrode material for all-vanadium redox flow batteries.

Co-modified MoO2 nanoparticles highly dispersed on N-doped carbon nanorods as anode electrocatalyst of microbial fuel cells

Cobalt-modified molybdenum dioxide nanoparticles highly dispersed on nitrogen-doped carbon nanorods (Co–MoO2/NCND), are synthesized from anilinium trimolybdate dihydrate nanorods, for the performance improvement of microbial fuel cell based on a mixed bacterial culture. Electrochemical measurements demonstrate that the as-synthesized Co–MoO2/NCND exhibits excellent electrocatalytic activity for the charge transfer on anode, providing the cell with a maximum power density of 2.06 ± 0.05 W m−2, which is strikingly higher than the bare carbon felt anode (0.49 ± 0.04 W m−2). The excellent performance of Co–MoO2/NCND is ascribed to the increased electronic conductivity of carbon nanorods by N-doping, the high ability of MoO2 to enrich electroactive bacteria, as demonstrated by high-throughput sequencing, and the enhanced activity of MoO2 by Co-modifying toward redox reactions in electroactive bacteria. This report provides a new concept of anode electrocatalyst fabrications for the application of microbial fuel cells in electricity generation and wastewater treatment.

Cu3Ge coated by nitrogen-doped carbon nanorods as advanced sodium-ion battery anodes

The sodium storage performance of Ge-based materials suffers from poor cycling stability caused by the volume variation and collapse of the structure during cycling process. In this work, Cu3Ge coated by nitrogen-doped carbon (Cu3Ge-NC) nanorods are prepared by annealing the mixture of CuGeO3 nanowires and polyacrylonitrile which acts as nitrogen and carbon source. As anode materials for sodium ion batteries, the outside carbon shell inhibits the serious volume change caused by Na+ insertion/extraction, and the Cu3Ge alloy enhances the sodiation capacity with rapid electron transfer and fast reaction kinetics. Corresponding kinetic analysis indicates pseudocapacitive behaviors play a dominant role in the total capacity at high rates. Hence, the Cu3Ge-NC exhibits favorable rate capability and cycling stability, which delivers a reversible capacity of 160 mAh g−1 for 500 cycles at a current density of 100 mA g−1.

Nitrogen-incorporated carbon nanotube derived from polystyrene and polypyrrole as hydrogen storage material

“Synthesis of nitrogen-doped carbon nanotubes from polymeric precursors (polystyrene and polypyrrole) by poly-condensation followed by carbonization under an inert atmosphere is reported. Three different carbonization temperatures (500 °C, 700 °C and 900 °C) were employed to synthesize three different carbon nanostructures with different morphologies. These were designated as NCNR-500 (nitrogen-doped carbon nanorods), NCBCT-700 (nitrogen-doped fused bead carbon nanotubes), and NCNT-900 (nitrogen-doped carbon nanotubes) according to morphology and carbonization temperature. Microstructure, morphology, porosity, and nitrogen content were characterized by several different techniques. The effects of carbonization temperature and the role of functional groups were also investigated. Total and excess hydrogen storage capacities of 2.0 wt% and 1.8 wt%, respectively, were measured at 298 K and 100 bar for the NCNT-900 material. This is higher than the capacities of the NCNR-500 and NCBCT-700 materials. NCNT-900 exhibited a porous structure with high specific surface area and total pore volume of 870 m/g and 0.62 cm3/g, respectively.

A synergistic effect of Co and CeO2 in nitrogen-doped carbon nanostructure for the enhanced oxygen electrode activity and stability

The development of efficient and durable non-precious cathode catalyst have been received the great interest to replace the commercial noble catalysts, thereby minimizing the overall cost of polymer electrolyte membrane fuel cells. We describe the synthesis of self-redox CeO2 supported Co in nitrogen-doped carbon nanorods (Co-CeO2/N-CNR) by the electro-spun method, and introduced as an enhanced bifunctional catalyst for oxygen reduction (ORR) as well as evolution (OER) reactions by the synergistic effect of oxygen buffer CeO2 with metallic Co. Systematic structural and optical studies confirm the formation and uniform distribution of CeO2 and Co particles in N-CNR. The X-ray photoelectron spectroscopy analysis of Co-CeO2/N-CNR reveals that the presence of Co2+ and multiple valence states of ceria (Ce4+ and Ce3+). The shift in binding energies of Co2+ and Ce3+ states confirm the possible interaction for the cooperative effect of ceria and cobalt during ORR and OER, and electrode stability improvement as well. The Co-CeO2/N-CNR catalyst shows the enhanced oxygen electrode potential of 0.84V (versus reversible hydrogen electrode), which is 100 and 196mV lower than Co/N-CNR and Pt/C, respectively, including the improved stability.

Mesoporous Co-CoO/N-CNR nanostructures as high-performance air cathode for lithium-oxygen batteries

A bifunctional air cathode for the electrochemical oxygen reduction and evolution in a Li-O2 battery comprising Co-CoO nanoparticles embedded in the nitrogen-doped carbon nanorods (Co-CoO/N-CNR) is presented. The nanorod morphology with mesoporous nanostructures can handle continuous formation and decomposition of Li2O2 and favors the transport of electrons and ions, therefore improves the rate capability and cycle stability. Moreover, the hierarchical mesoporous Co-CoO/N-CNR reduces the overall overpotential over the cycle and decreases the side reaction between Li2O2 and carbon surface, leading to a significant enhancement of the specific capacity and cycling capability. With the cooperative effect of Co-CoO/N-CNR and porous nature, Co-CoO/N-CNR cathode delivers a high discharge specific capacity of 10,555 mAh g−1 at 100 mA g−1 and long cycle stability for over 86 cycles without any capacity loss at a high cutoff capacity of 1000 mAh g−1. Furthermore, excellent performance of 7514 mAh g−1 at 500 mA g−1 is achieved.

Hierarchical design of nitrogen-doped porous carbon nanorods for use in high efficiency capacitive energy storage

We report a novel synthesis route for creating 3D interconnected hierarchical porous nitrogen-doped carbon nanorods (3D-IPCRs) using 1D polyaniline nanorods as a precursor and SiO2 as a porogen.

Nitrogen and gold nanoparticles co-doped carbon nanofiber hierarchical structures for efficient hydrogen evolution reactions

A novel hierarchical structure was fabricated by integrating gold nanoparticles (AuNPs) on nitrogen-doped carbon nanorods encapsulating carbon nanofibers (AuNPs@NCNRs/CNFs), and the composite was demonstrated as an electrocatalyst for the hydrogen evolution reaction (HER). First, polyaniline nanorods (PNRs) were grown on the surfaces of the CNFs, and the PNR/CNF hybrids were then decorated with small, well-dispersed and size-controlled AuNPs. The morphology, structure and chemical states of the AuNPs@NCNRs/CNFs hybrids were characterized by field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The AuNPs@NCNRs/CNFs can be used directly as an electrode and exhibit good HER activity with a relatively low onset potential of 126mV, a Tafel slope of 93mVdec−1 and remarkable durability in 0.5M H2SO4. The enhancement of the HER activity could be attributed to the synergetic effect between the nitrogen-doped carbon fibers and the AuNPs.