Nitrogen-doped Carbon Nanoparticles Research Articles

Amorphous Cobalt-Impregnated Nitrogen-Doped Carbon Encapsulation Nanochain Enhances Long-Lasting Electrochemical Water Splitting.

Electrochemical water splitting (EWS) is a promising way to attain H2, which has been deemed an ideal substitution for fossil fuels because of renewable and eco-friendly benefits. Developing an amorphous-based simple and structurally flexible non-noble catalyst to offer high performance for commercial applications has become a current interest. Amorphous cobalt-anchored nitrogen-doped carbon nanoparticles (Co@NC-NPs) were designed to have a low overpotential and Tafel as a bifunctional electrocatalyst (HER - 142 mV/80 mV dec-1 and OER - 250 mV/72 mV dec-1) to achieve 10 mA cm-2 in 1.0 KOH. FE-SEM and HR-TEM described the interconnected nanochain morphology and purity of Co@NC-NPs electrocatalyst, which were confirmed by EDX and elemental mapping. In a full cell water electrolyzer, Co@NC-NPs(+,-) may act as an anode and cathode electrode material to achieve 1.60 V @ 10 mA cm-2 in a wide pH. The efficient Co@NC-NPs are stable for 100 h without obvious recession. In solar cell applications, Co@NC-NPs(+,-) catalyst was employed as both positive and negative terminals and evolved enormous bubbles of O2 and H2. As previously mentioned, we covered the amorphization strategy with the optimistic role of structural flexibility and defects to enrich the active sites to improve the electrocatalytic stability. As a promising opinion, the amorphous electrocatalyst provides ultraefficiency for forthcoming developments in EWS.

Graphitic carbon nitride film deposited with nitrogen-doped carbon nanoparticles as electrode for high-performance supercapacitors

Graphitic carbon nitride film deposited with nitrogen-doped carbon nanoparticles as electrode for high-performance supercapacitors

Performance of Nitrogen-Doped Carbon Nanoparticles Carrying FeNiCu as Bifunctional Electrocatalyst for Rechargeable Zinc-Air Battery.

Catalysts for zinc-air batteries (ZABs) must be stable over long-term charging-discharging cycles and exhibit bifunctional catalytic activity. In this study, by doping nitrogen-doped carbon (NC) materials with three metal atoms (Fe, Ni, and Cu), a single-atom-distributed FeNiCu-NC bifunctional catalyst is prepared. The catalyst includes Fe(Ni-doped)-N4 for the oxygen evolution reaction (OER), Fe(Cu-doped)-N4 for the oxygen reduction reaction (ORR), and the NiCu-NC catalytic structure for the oxygen reduction reaction (ORR) in the nitrogen-doped carbon nanoparticles. This single-atom distribution catalyst structure enhances the bifunctional catalytic activity. If a trimetallic single-atom catalyst is designed, it will surpass the typical bimetallic single-atom catcalyst. FeNiCu-NC exhibits outstanding performance as an electrocatalyst, with a half-wave potential (E1/2) of 0.876V versus RHE, overpotential (Ej = 10) of 253mV versus RHE at 10mA cm-2, and a small potential gap (ΔE = 0.61V). As the anode in a ZAB, FeNiCu-NC can undergo continuous charge-discharged cycles for 575h without significant attenuation. This study presents a new method for achieving high-performance, low-cost ZABs via trimetallic single-atom doping.

Size-dependent activity of Fe-N-doped mesoporous carbon nanoparticles towards oxygen reduction reaction

The rational design of Fe–N–C catalysts that possess easily accessible active sites and favorable mass transfer, which are usually determined by the structure of catalyst supports, is crucial for the oxygen reduction reaction (ORR). In this study, an oleic acid-assisted soft-templating approach is developed to synthesize size-controlled nitrogen-doped carbon nanoparticles (ranging from 130 nm to 60 nm and 35 nm, respectively) that feature spiral mesopores on their surface (SMCs). Next, atomically dispersed Fe–Nx sites are fabricated on the size-tunable SMCs (Fe1/SMC-x, where x represents the SMC size) and the size-dependent activity toward ORR is investigated. It is found that the catalytic performance of Fe1/SMCs is significantly influenced by the size of SMCs, where the Fe1/SMC-60 catalyst shows the highest ORR activity with a half-wave potential of 0.90 V vs. RHE in KOH electrolyte, indicating that the gas-liquid-solid three-phase interface on the Fe1/SMC-60 enhances the accessibility of Fe–Nx sites. In addition, when using Fe1/SMC-60 as the cathode catalyst in aqueous zinc-air batteries (ZABs), it delivers a higher open-circuit voltage (1.514 V), a greater power density (223 mW cm−2), and a larger specific capacity/energy than Pt/C-based counterparts. These results further highlight the potential of Fe1/SMC-60 for practical energy devices associated with ORR and the importance of size-controlled synthesis of SMCs.

Highly Stable ZnS Anodes for Sodium-Ion Batteries Enabled by Structure and Electrolyte Engineering.

Zinc sulfide is a promising high-capacity anode for practical sodium-ion batteries, considering its high capacity and the low cost of zinc and sulfur sources. However, the pulverization of particulate zinc sulfide causes active mass collapse and penetration-induced short circuits of batteries. Herein, a zinc sulfide encapsulated in a nitrogen-doped carbon shell (ZnS@NC) was developed for high-performance anodes. The confinement effect of nitrogen-doped carbon stabilizes the active mass structure during cycling thanks to the robust chemically and electronically bonded connections between nitrogen-doped carbon and zinc sulfide nanoparticles. Furthermore, the cycling stability of the ZnS@NC anode is boosted by the robust inorganic-rich solid electrolyte interphase (SEI) formed in cyclic and linear ether-based electrolytes. The ZnS@NC anode displayed a reversible specific capacity of 584 mAh g-1, an excellent rate capability of 327 mAh g-1 at 70 A g-1, and a highly stable cycling performance over 10000 cycles. This work provides a practical and promising approach to designing stable conversion anodes for high-performance sodium-ion batteries.

Trace amount Pt anchored on nitrogen-doped carbon nanoparticle with hollow capsule structure for efficient electrocatalytic oxygen reduction

The utilization of sustainable green energies requires the energy conversion devices to enhance the convenience of use and storage. The oxygen reduction reaction (ORR), as one of the necessary steps in the operation of these devices, exhibits a slow reaction kinetic rate that seriously affects energy conversion and output efficiency. Due to the low abundance and poor stability of Pt, it is essential to develop high-performance oxygen reduction catalysts with low Pt loading. In this work, a composite precursor consisting of ZIF-8 coupled with ferrocene and chloroplatinic acid was prepared, and subsequently derived to obtain nitrogen-doped carbon nanoparticles with hollow capsule morphology on the surface. These hollow capsule structure formed with the assistance of Pt and Fe significantly enhances the performance of Pt/FC@ZIF-8-C nanoparticles as the ORR electrocatalyst, exhibiting superior catalytic activity and stability compared to Pt/C at a low Pt loading (0.7 wt%). This is very important for promoting the design and preparation of Pt-based catalysts, as well as the application of energy conversion and storage devices in the field of green energy sources.

Polyacrylonitrile-Derived Nitrogen-Doped Carbon Nanoparticles Decorated with Fe3C for Wide-Band Microwave Dissipation

Polyacrylonitrile-Derived Nitrogen-Doped Carbon Nanoparticles Decorated with Fe3C for Wide-Band Microwave Dissipation

Nitrogen-doped hollow carbon nanoparticles with optimized multiscale nanostructures via dolomite-assisted chemical vapor deposition for high-performance potassium-ion capacitor

Carbon-based materials are considered as promising anode candidates for potassium-ion storage with the key bottlenecks lying in the slow kinetics and huge volume expansion caused by the large size of K+. Herein, nitrogen-doped hollow carbon nanoparticles (NHCP) with optimized multiscale nanostructures are synthesized by a natural template-assisted chemical vapor deposition process. Benefiting from the stacking nanoparticles structure with hierarchical pores, high level of pyridinic-/pyrrolic-N, and enlarged interlayer spacing, the constructed NHCP anode delivers superior K+ storage properties in terms of high reversible capacity (412.7 mAh g−1 at 0.03 A g−1), favorable rate capability, and long cyclic stability. The detailed experimental and computational studies reveal the combined storage mechanism of K+ adsorption and insertion in the multiscale nanostructure of NHCP. To achieve high areal capacities, self-supported NHCP electrodes with high mass loadings (3.41 and 6.23 mg cm−2) were constructed by a vacuum-assisted infiltration process which exhibits greatly improved areal capacities as compared with the traditional slurry coating electrode. The assembled full-carbon potassium-ion capacitor based on NHCP anode exhibits high energy and power densities (168 Wh kg−1 and 9.4 kW kg−1) and a long cycling lifespan (83.9% capacity retention after 10000 cycles at 1.0 A g−1). This work provides a facile fabrication method for porous carbon electrodes with high mass loadings and capacities, which holds the potential for practical application.

Application of nitrogen-doped carbon particles modified electrode for electrochemical determination of tetrazepam as muscle relaxant drug

The objective of this work was to create a modified carbon paste electrode (N-CNP/CPE) with nitrogen-doped carbon nanoparticles for electrochemically detecting tetrazepam (TZ) as a muscle relaxant in samples of human blood serum. N-CNP was created using a microwave-assisted process, and N-CNP was applied to the CPE surface using an electrodeposition technique. N atoms were effectively doped within the carbon framework of CNP/CPE, according to the results of morphology and structure characterization using FE-SEM, XRD, and EDS analyses. Additionally, abundant and evenly distributed pores and a spherical structure of N-CNP were electrodeposited on the CPE surface. The electrochemical analyses' findings show that the N-CNP/CPE TZ sensor is sensitive and selective, with a broad linear range of 0–650 µg/mL and a sensitivity value of 0.29478 µA/µg.mL−1. The proposed TZ sensor's limit of detection was discovered to be a low value of 5 ng/mL, which was a relatively low value of LOD and a broad linear range compared to other TZ sensors. Results indicated acceptable recovery values (more than 98.53%) and appropriate precision (RSD less than 5.08%), as well as good agreement between the DPV measurements and ELISA technique, for the determination of TZ in prepared samples of blood serum from bodybuilding athletes. These results show that the TZ content of blood samples from athletes may be monitored using the N-CNP/CPE as a trustworthy TZ sensor.

N-Doped carbon nanoparticles on highly porous carbon nanofiber electrodes for sodium ion batteries.

Nitrogen doped carbon nanoparticles on highly porous carbon nanofiber electrodes were successfully synthesized via combining centrifugal spinning, chemical polymerization of pyrrole and a two-step heat treatment. Nanoparticle-on-nanofiber morphology with highly porous carbon nanotube like channels were observed from SEM and TEM images. Nitrogen doped carbon nanoparticles on highly porous carbon nanofiber (N-PCNF) electrodes exhibited excellent cycling and C-rate performance with a high reversible capacity of around 280 mA h g-1 in sodium ion batteries. Moreover, at 1000 mA g-1, a high reversible capacity of 172 mA h g-1 was observed after 300 cycles. The superior electrochemical properties were attributed to a highly porous structure with enlarged d-spacings, enriched defects and active sites due to nitrogen doping. The electrochemical results prove that N-PCNF electrodes are promising electrode materials for high performance sodium ion batteries.

Biomass coffee grounds derived nitrogen-doped ultrafine carbon nanoparticles as an efficient electrocatalyst to oxygen reduction reaction

A nitrogen-doped carbon-based catalyst (Fe-C-CG) to oxygen reduction reaction (ORR) is synthesized by pyrolyzing a precursor from coffee grounds, iron chloride and commercial carbon black in ammonia atmosphere. The coffee grounds are pyrolyzed to carbon particles with diameters about 20 nm with the facilitation of carbon black. The carbon nanoparticles show higher reactive activity with ammonia to achieve the doping of nitrogen atoms to carbon with 3.33 at% of content in Fe-C-CG, which is greater than 0.47 at% in the product from commercial carbon black (Fe-C). Resultantly, the Fe-C-CG exhibits high ORR activity with 0.87 V of half wave potential and 5.48 mA cm−2 of limited diffusion current, which highly surpass the 0.71 V, 4.19 mA cm−2 for Fe-C, and are comparable with 0.86 V and 4.52 mA cm−2 for Pt/C catalyst, respectively. The Zn-air battery assembled with Fe-C-CG delivers 142 mW cm−2 of maximum power density and 774 mAh g−1Zn of specific capacity, and can stably work at 1.212–1.257 V of discharge voltage at 10 mA cm−2. This work provides a strategy to prepare a nonprecious metal and nitrogen doped carbon catalyst to ORR by using biomass as the basic material.

Graphite carbon nitride loaded nitrogen-doped carbon and cobalt nanoparticles ternary photocatalyst for enhanced solar-driven hydrogen evolution

In this paper, we designed a composite photocatalytic system in which cobalt nanoparticles (Co NPs) are attached to nitrogen-doped carbon (N-d-C) and co-bonded to the surface of the noted photocatalyst graphite carbon nitride (g-C3N4), showing an excellent photocatalytic hydrogen production. The bulk g-C3N4 was formed in the first thermal treatment in air using melamine as a precursor. Subsequently, the secondary calcination under N2 led to the synchronous fabrication of N-d-C/Co NPs and their combination with g-C3N4 to form a novel ternary photocatalyst (g-C3N4/N-d-C/Co NPs). Co NPs exposed on the surface of the nanomaterials endowed much more reaction sites than g-C3N4 for photocatalytic hydrogen production. Meanwhile, the embedded N-d-C provided an additional transfer approach for photocarriers. The as-prepared composite nanomaterials own a relatively high specific surface area of 97.45 m2 g−1 with an average pore size of 3.83 nm. As a result, compared with pristine g-C3N4 (∼25.35 μmol g−1 h−1), the photocatalytic performance was increased by over 10 times (∼270.05 μmol g−1 h−1). Our work gives a novel approach for highly active g–C3N4–based photocatalysts in the field of photocatalysis.

Cd2+ ion adsorption and re-use of spent adsorbent with N-doped carbon nanoparticles coated on cerium oxide nanorods nanocomposite for fingerprint detection

This work provides a novel approach to prepare nitrogen-doped carbon nanoparticles (CNPs) coated on a cerium oxide nanorods nanocomposite (N-CNPs/CeO2NRsnC) for the uptake of cadmium (Cd2+) ions and re-using the spent adsorbent, Cd2+-CNPs/CeO2NRsnC for latent fingerprint detection (LFP). N-CNPs were prepared by a thermal method with urea and cabbage powder as precursors. N-CNPs/CeO2NRsnC was developed with N-CNPs and CeO2NRs with a hydrothermal method and characterized by various instrument methods like UV-visible, FT-IR, XRD, BET, XPS, SEM, and TEM. The N-CNPs/CeO2NRsnC had a greater surface area (9.96 m2/g) than N-CNPs (0.64 m2/g). The synthesized N-CNPs/CeO2NRsnC proved to be a good sorbent material to remove Cd2+ from water at a maximum pH 8 and dosage 10 mg/L. The adsorption was spontaneous and endothermic at 25 ºC. In addition, Cd2+-N-CNPs/CeO2NRsnC has been shown to be sensitive and selective for LFP identification on several porous substrates. It is therefore a good labeling agent for latent fingerprint identification in forensic science.

Synergistic capture and conversion of polysulfides in cathode composites with multidimensional framework structures

The application of lithium–sulfur batteries are seriously hindered by their poor cycle stability and low sulfur utilization due to their inevitable polysulfide shuttle effect and slow reaction kinetics. Here, Mo2C nanorods that were surface-decorated with metallic–organic framework-derived nitrogen-doped carbon and ultrasmall cobalt nanoparticles (NC–Co@Mo2C) were used as the materials for lithium–sulfur battery cathodes. The prepared NC–Co@Mo2C@S composites had the specific capacity of 1073 mAh·g−1 (0.2 C) and the retained 806 mAh·g−1 after 200 cycles, thus showing excellent discharge specific capacity and cycling stability. The Mo2C nanorods can adsorb lithium polysulfides (LiPSs) through the formation of MoS bonds. Cobalt nanoparticles electrocatalytically accelerated the redox kinetic conversion of LiPSs. Nitrogen doping can effectively reduce the energy potential barrier. The interconnected multidimensional backbone of NC–Co@Mo2C composites contributed to electrolyte permeation, fast electron/Li+ transport, and sufficient volume change buffering. Therefore, the synergistic effect of the adsorption ability of Mo2C nanorods and the catalytic ability of cobalt nanoparticles can effectively improve the sulfur fixation ability of the composites and greatly suppress the shuttle effect.

Atomic iron coordinated by nitrogen doped carbon nanoparticles synthesized via a synchronous complexation-polymerization strategy as efficient oxygen reduction reaction electrocatalysts for zinc-air battery and fuel cell application

Developing atomic transition metal coordinated by nitrogen doped carbon (M−N−C) eletrocatalysts for oxygen reduction reaction (ORR) is critical to achieve low cost metal-air batteries and fuel cells. Herein, a general method of synthesizing M−N−C was developed via a synchronous complexation-polymerization strategy, in which nitrogen-containing ligand was coordinated with specific transition metal ions and diamino aromatic compound was simultaneously polymerized by the metal ion as initiator; by the following pyrolysis in a molten NaCl bath, M−N−C was finally synthesized. Fe-N-C was synthesized by this strategy using 2, 4, 6-Tri (2-pyridyl)-1, 3, 5-triazine (TPTZ) as ligand for FeCl2, and 1, 8-Diaminonaphthalene (DAN) as monomer of polymerization. Results demonstrate that introducing DAN into TPTZ-Fe2+ significantly affect the derived carbon structure and electrochemical performance of corresponding Fe-N-C. The Fe-N-C prepared by TPTZ and DAN with the molar ratio of 1:1 shows excellent ORR activity and durability, whose initial half-wave potential is 0.90 V in 0.1 M KOH and 0.80 V in 0.5 M H2SO4 respectively, after 10 K cycles, the potential is only 14 mV loss in 0.1 M KOH and 20 mV decay in 0.5 M H2SO4. And the ORR performance as cathode is further proved by a single practical Zn-air battery with a maximum power density of 192 mW cm−2 and a specific capacity of 800 mAh gZn-1, much higher than 137 mW cm−2 and 735 mAh gZn-1 of the same loading of commercial Pt/C catalyst and proton exchange membrane fuel cell with a high power output of 640 mW cm−2. Attributed to the vast kinds of ligands, metal ions and polymerizing monomers, this strategy provides a flexible platform of synthesizing advanced M−N−C catalysts, compared with other reported methods.

Atomic Iron Coordinated by Nitrogen Doped Carbon Nanoparticles Synthesized Via a Synchronous Complexation-Polymerization Strategy as Efficient Oxygen Reduction Reaction Electrocatalysts for Zinc-Air Battery and Fuel Cell Application

Atomic Iron Coordinated by Nitrogen Doped Carbon Nanoparticles Synthesized Via a Synchronous Complexation-Polymerization Strategy as Efficient Oxygen Reduction Reaction Electrocatalysts for Zinc-Air Battery and Fuel Cell Application

Photoelectrochemical and photosensing study of nitrogen doped carbon nanoparticles sensitized TiO2 nanorods

Nitrogen doped Carbon Nanoparticles (NCNPs) were synthesized using a thermal pyrolysis method. NCNPs are crystalline in nature with diameter ranges from size 9–36 nm. Optical absorption study revealed two major peaks. The sharp peak at 220 nm is attributed to π → π* transition in aromatic sp2 CC bonds and the broad peak at 300–400 nm corresponds to n → π* transition in C=O/C=N bonds. NCNPs are highly luminescent and demonstrated excitation dependent green photoemission under 340-500 nm photoexcitation. TiO2 nanorods (TiO2 NRs) were grown on Fluorine doped tin oxide (FTO) coated glass substrates using hydrothermal method. Photoelectrochemical properties of pristine TiO2 NRs and NCNPs sensitized TiO2 NRs has been studied in detail. NCNPs sensitized nanorods demonstrated superior photoconversion efficiency (η) of 1.37% and incident-photon-to-current conversion efficiency (IPCE) of 80% at 340 nm.

Oxygen and nitrogen-doped metal-free microalgae carbon nanoparticles for efficient hydrogen production from sodium borohydride in methanol

Here, the oxygen(O) and nitrogen(N) doped metal-free carbon synthesis including potassium hydroxide (KOH) activation of Spirulina Platensis microalgae, followed by nitric acid (HNO3) activation is reported for the first time. Oxygen and nitrogen-doped metal-free catalysts were investigated for efficient hydrogen (H2) production from methanolysis of sodium borohydride (NaBH4). Compared to the catalyst obtained with the KOH activation, the catalytic activity for O and N doped metal-free showed about a four-fold improvement. The catalysts were analysed by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD), nitrogen adsorption, elemental analysis and Fourier-transform infrared spectroscopy (FTIR). The effects of temperature, NaBH4 amounts, catalyst loading and reusability experiments on the catalytic performance of obtained metal-free catalysts by H2 release from NaBH4 methanolysis were performed. This study can provide a new alternative strategy to produce specific metal-free carbon catalysts doped heteroatom for environmentally friendly conversion to produce H2 efficiently.

Dimethylglyoxime Clathrate as Ligand Derived Nitrogen-Doped Carbon-Supported Nano-Metal Particles as Catalysts for Oxygen Reduction Reaction.

Nitrogen-doped carbon-supported metal nano-particles show great promise as high-performance catalysts for novel energies, organic synthesis, environmental protection, and other fields. The synergistic effect between nitrogen-doped carbon and metal nano-particles enhances the catalytic properties. Thus, how to effectively combine nitrogen-doped carbon with metal nano-particles is a crucial factor for the synthesis of novel catalysts. In this paper, we report on a facile method to prepare nitrogen-doped carbon-supported metal nano-particles by using dimethylgly-oxime as ligand. The nano-particles of Pd, Ni, Cu, and Fe were successfully prepared by the pyrolysis of the corresponding clathrate of ions and dimethylglyoxime. The ligand of dimethylglyoxime is adopted as the source for the nitrogen-doped carbon. The nano-structure of the prepared Pd, Ni, Cu, and Fe particles are confirmed by X-ray diffraction, scanning electron microscopy, and trans-mission electron microscopy tests. The catalytic performances of the obtained metal nano-particles for oxygen reduction reaction (ORR) are investigated by cyclic voltammetry, Tafel, linear sweeping voltammetry, rotating disc electrode, rotating ring disc electrode, and other technologies. Results show that the nitrogen-doped carbon-supported metal nano-particles can be highly efficient catalysts for ORR. The results of the paper exhibit a facile methodology to prepare nitrogen-doped carbon-supported metal nano-particles.

Nitrogen-Doped Amorphous Zn-Carbon Multichannel Fibers for Stable Lithium Metal Anodes.

The application of lithium metal anodes for practical batteries is still impeded by safety issues and low Coulombic efficiency caused mainly by the uncontrollable growth of lithium dendrites. Herein, two types of free-standing nitrogen-doped amorphous Zn-carbon multichannel fibers are synthesized as multifunctional hosts for lithium accommodation. The 3D macroporous structures endow effectively reduced local current density, and the lithiophilic nitrogen-doped carbon and functional Zn nanoparticles serve as preferred deposition sites with low nucleation barriers to guide uniform lithium deposition. As a result, the developed anodes exhibit remarkable electrochemical properties in terms of high Coulombic efficiency for more than 500 cycles at various current densities from 1 to 5 mA cm-2 , and symmetric cells show long-term cycling duration over 2000 h. Moreover, full cells based on the developed anode and a LiFePO4 cathode also demonstrate superior rate capability and stable cycle life.