Synthesis Of Nitrogen-doped Porous Carbon Research Articles

Facile synthesis of nitrogen-doped porous carbon as robust electrode for supercapacitors

Porous carbon nanomaterials are highly attactive as electrode materials for supercapacitors (SCs), but the relatively low capacitance as a result of their intrinsic electric double-layer mechanism severely hinders their practical applications. In addition, the complicated preparation processes of most porous carbon nanomaterials previously reported is less impressive for large-scale application. In this work, we report an efficient and simple method to synthesize porous N doped carbon (PNC) on flexible carbon cloth as high-performance electrode for SCs. Benefiting from the unique porous architecture and high N dopant content, the as-fabricated PNC electrode delivers excellent capacitive performance. A high areal capacitance of 682.8 mF cm−2 at 2 mA cm−2 and outstanding cycling performance (less than 4% capacitance fading after 10,000 cycles) is achieved by this PNC electrode. This work opens up new opportunities in developing advanced carbon-based electrode for energy storage.

Facile Aqueous Route to Nitrogen-Doped Mesoporous Carbons.

An aqueous-based approach for the scalable synthesis of nitrogen-doped porous carbons with high specific surface area (SSA) and high nitrogen content is presented. Low molecular weight polyacrylonitrile (PAN) is solubilized in water in the presence of ZnCl2 that also acts as a volatile porogen during PAN pyrolysis to form mesoporous structures with significantly increased SSA. By templating with commercial SiO2 nanoparticles, nanocellulose fillers or filter paper, nanocarbons with SSA = 1776, 1366, and 1501 m2/g, respectively and 10 wt % N content were prepared. The materials formed by this benign process showed excellent catalytic activity in oxygen reduction reaction via the four-electron mechanism.

Protonated g-C3N4@polypyrrole derived N-doped porous carbon for supercapacitors and oxygen electrocatalysis

Preparation of high-performance carbon materials with an abundance of heteroatoms, edges, and defects for sustainable energy-conversion technologies, such as supercapacitors and oxygen reaction reduction (ORR), are still a challenge. Herein, we reported a facile strategy for the large-scale synthesis of nitrogen-doped porous carbon via carbonization of core-shell structured protonated g-C3N4@polypyrrole (P-g-C3N4@PPy) nanocomposites. Polypyrrole provided both the carbon and heteroatom sources, while P-g-C3N4 acted not only as a sacrificial template but also as nitrogen sources. Porous carbon derived from P-g-C3N4@PPy (denoted as PCN@PPy-C-900) exhibited a specific capacitance of 350 F g−1 at a current density of 5 A g−1 and a high-rate capability (320 F g−1) at 20 A g−1 in 6 M KOH aqueous solution, as well as good long-term stability after 1000 cycles. In addition, PCN@PPy-C-900 also displayed excellent electrocatalytic performances in ORR in 0.1 M KOH aqueous solution. The excellent electrochemical performances provide guidance for the structure design of this promising class of multifunctional carbon-based materials which can be large scale applied to supercapacitors, ORR, and other fields.

Nitrogen-doped porous carbon derived from imidazole-functionalized polyhedral oligomeric silsesquioxane

Nitrogen-doped porous carbons with uniformed pore structure and large surface area are promising materials as sorbents for acidic gases and electrocatalysts for oxygen-related reactions. Herein, we report the synthesis of nitrogen-doped porous carbon (NPC) materials through carbonization of imidazole-functionalized polyhedral oligomeric silsesquioxane (POSS) at 900 °C followed by removal of POSS blocks. The imidazole moieties act as both nitrogen and carbon sources and the POSS blocks are nano-sized hard templates. The resulting NPC has a surface area of 980 m2g−1 with average pore size of 4.7 nm and the pyridinic nitrogen in the formed NPC contribute to about 33% of overall nitrogen species. The carbon dioxide adsorption property and the electrocatalytic performance toward oxygen reduction reaction of the formed NPC are further evaluated. The formed NPC materials exhibit a total carbon dioxide adsorption capacity of 0.30 mmolg−1 at 30 °C under the partial pressure of carbon dioxide of 0.2 bar. Although the formed NPC is less active than commercial Pt/C catalyst for oxygen reduction reaction, the half-wave potential shifts to the negative side by only about 10 mV after 10000 cycling tests, demonstrating the great stability of the formed NPC materials.

Facile synthesis of nitrogen-doped porous carbons for CO2 capture and supercapacitors

Nitrogen-doped porous carbons are attracting considerable attention as adsorbents in CO2 uptake area or for supercapacitors. In this work, nitrogen-doped porous carbons with a high surface area are efficiently prepared through a facile approach by using polyvinylpyrrolidone as carbon and nitrogen sources through ZnCl2 activation at 400–700 °C for 4 h under N2 atmosphere. The obtained nitrogen-doped porous carbons exhibit a narrow microporous structure (0.4–1.0 nm), high specific surface area (up to 1040 m2 g−1) and corresponding N content of up to 6.3 wt%. These findings are ascribed to the unique features of high specific surface area and rich N content. Such nitrogen-doped porous carbons show high CO2 capture of 4.0 mmol g−1 (0 °C) and 2.5 mmol g−1 (25 °C), as well as excellent capacitive performance with a specific capacitance of 292 F g−1 (in 2 M KOH) at a current density of 0.5 A g−1 and cycling stability. A symmetrical supercapacitor based on NPCs shows high energy density (23.2 W h kg−1 at 0.5 A g−1) and good cycle stability (96.8% capacitance retention after 5000 cycles) in symmetric two-electrode systems.

Synthesis of nitrogen-doped porous carbon from zeolitic imidazolate framework-67 and phenolic resin for high performance supercapacitors

An one-pot method has been developed to synthesize a new type of composite material, which can be used as carbon source to produce electrode material for supercapacitors. Specifically, zeolitic imidazolate framework-67 (ZIF-67) crystal was synthesized firstly in 2-methylimidazol aqueous solution, then silica primary particles (from hydrolysis of tetraethylorthosilicate) and phenolic resin (from aggregation of resorcinol and formaldehyde) co-condensed on the surface of ZIF-67 crystal in the same system. The key to realize one-pot method is that 2-methylimidazol aqueous solution shows alkalescence, which can catalyze the hydrolysis of tetraethylorthosilicate and the aggregation of phenolic resin. After carbonization and remove of silica, the N-doped porous carbon (Carbon-ZSR) with high degree of graphitization, wide pore size distribution and maximum specific surface area was obtained. When it is used for supercapacitors as the electrode material, the Carbon-ZSR shows excellent electrochemical properties, large specific capacitance (305 Fg−1 at 1 Ag−1), high rate performance (229 Fg−1 keeps at 10 Ag−1) and excellent electrochemical stability (the specific capacitance maintains 98.4% after 5000 cycles at 10 Ag−1), which suggest that the ZIF-derived nitrogen-doped porous carbon is an outstanding electrode material for energy storage devices.

Excellent electrochemical properties and large CO2 capture of nitrogen-doped activated porous carbon synthesised from waste longan shells

We present a low-cost approach for facile synthesis of nitrogen-doped porous carbons by utilising waste longan shell as carbon source and carbamide as additional nitrogen source through KOH activation at 600°C–900°C for 2hours under N2 atmosphere. The obtained porous carbons possess highly-developed ultra-micropores (approximately 0.6nm), an ultrahigh specific surface area (up to 3260 m2 g-1) and a nitrogen content of 2.3 at.%. The porous carbon exhibits excellent electrochemical properties (a high specific capacity up to 322 F g-1 and an energy density of up to 20.4W h kg-1) at a current density of 0.5 A g-1 in 6M KOH and an excellent cycle stability (retained almost 96.2% specific capacitance after 5000 cycles). In addition, the porous carbon shows high CO2 adsorption capacities of 5.6 mmol g-1 (at 0°C) and 4.3 mmol g-1 (at 25°C) and high CO2 selectivity against N2. These results indicate that the fabricated porous carbon is a promising electrode material for supercapacitors and a solid adsorbent for CO2 uptake.

One-step synthesis of nitrogen-doped porous carbon for high performance supercapacitors

We report a simple synthesis of nitrogen-doped porous carbon materials by one-step carbonization of pure sodium glutamate in inert atmosphere without any activation. The surface area, pore structure, and electrochemical properties of the resultant carbon materials can be tuned simply by changing the carbonization temperature. The carbon materials are characterized by heteroatom (N, O) doping, interconnected porous carbons framework with high surface area (1873 m2 g−1), large pore volume (1.10 cm3 g−1), and high yield. While the nitrogen content decreases from 7.15 at% at 600 °C to 4.03 at% at 900 °C. These features confer the as-obtained nitrogen-doped porous-carbon materials with high specific capacitance, good rate capability, and excellent cycling stability (88.15% of capacitance retention after 5000 cycles) in 2 M NaNO3 electrolyte.

Facile synthesis of nitrogen-doped porous carbon for high-performance supercapacitors

Nitrogen-doped porous carbon (NCs) have been synthesized by direct pyrolysis of a mixture containing melamine, iron nitrate and ethylene diamine tetraacetic acid (EDTA).

Self-assembly synthesis of nitrogen-doped mesoporous carbons used as high-performance electrode materials in lithium-ion batteries and supercapacitors

Guanine was, for the first time, used as a nitrogen source during the synthesis of nitrogen-doped porous carbons (NMCs) with enhanced electrochemical performance.

Low-cost and massive preparation of nitrogen-doped porous carbon for supercapacitor application

Massive synthesis of nitrogen-doped porous carbon with superior supercapacitor performance.

One-step synthesis of nitrogen-doped porous carbon for supercapacitors utilizing KNO3 as an electrolyte

Nitrogen-doped porous carbons were prepared using a facile method, with low-biotechnology fulvic acid potassium salts as a precursor. The prepared carbons had a high surface area (1623 m2 g−1) and good electrochemical properties, making them suitable electrode materials for supercapacitors. Nitrogen-doped porous carbons were tested as an electrode in both 6 M KOH aqueous solution and different concentrations KNO3 aqueous solution. The nitrogen-doped porous carbons with unique microstructure and nitrogen functionalities exhibited a capacitance of 235 F g−1 in a 6 M KOH aqueous solution. Electrochemical investigation showed that the nitrogen-doped porous carbons exhibited a broad potential operational window in a 2.5 M KNO3 aqueous solution. Furthermore, a high capacitance retention of 88.1 % was achieved even after 5000 cycles at 1.7 V. Potassium nitrate solutions in a wide range of concentrations were also proven to be promising electrolytes for electrochemical capacitors because they are cheap, noncorrosive, electrochemically stable, and compatible to diverse current collectors.

Nitrogen-doped porous carbon with an ultrahigh specific surface area for superior performance supercapacitors

Owing to its abundant nitrogen content, silk cocoon is a promising precursor for the synthesis of Nitrogen-doped porous carbon (N-PC). Using a simple staged KOH activation, the prepared sample displays particular nanostructure with ultrahigh specific surface area (3841 m2 g−1) and appropriate pore size, providing favorable pathways for transportation and penetration of electrolyte ions. Additionally, the doped nitrogen atoms ensure the samples with pseudocapacitive behavior. Those special characteristics endow N-PCs with high capacity, low resistance, and long-term stability, indicating a wonderful potential for application in energy-storage devices.

Molten salt synthesis of nitrogen-doped porous carbons for hydrogen sulfide adsorptive removal

Nitrogen-doped porous carbons (NPCs) with high hydrogen sulfide (H2S) adsorption capacity have been prepared through the molten-salt approach, using d-glucose as carbon source, melamine as nitrogen source and eutectic salt (LiCl/KCl) as porogen. The NPCs possess tunable nitrogen content (3.07–24.31 wt.%) and specific surface area (451–1190 m2/g) with the changing of the weight ratio of nitrogen source to carbon source and synthesis temperature. The H2S adsorptive performance of NPCs is highly superior to that of non-doped porous carbon. X-rays photoelectron spectroscopy analyses combined with quantum chemical calculations demonstrate that the adsorption performance of the as-prepared NPCs depends on their nitrogen content and N-bonding configurations in the carbon materials, as well as their porosity. Pyridinic nitrogen doped carbon in NPCs have stronger interaction with H2S compared to pyrrolic and graphitic nitrogen doped carbon. Based on the advantages of the developed porosity and abundant nitrogen functional groups, the saturated sorption capacities of 0.97–1.25 mmol H2S/g can be achieved over NPCs at 25 °C under dry and anaerobic conditions.

Self-template synthesis of nitrogen-doped porous carbon derived from zeolitic imidazolate framework-8 as an anode for sodium ion batteries

Nitrogen-doped porous carbon (NPC) was successfully synthesized with zeolitic imidazolate framework-8 (ZIF-8) as the precursor at a high carbonization temperature of 950°C, which can generate relatively pure NPC. When used as the anode materials for sodium ion batteries, the NPC exhibits an excellent rate capability and cycling stability, delivering a reversible capacity of 144.7mAhg−1 at a current density of 50mAg−1 after 200 cycles and a capacity of 117.6mAhg−1 at a high current density of 400mAg−1, which is attributed to the existence of mesoporous structure and the introduction of nitrogen atoms. The electrochemical results indicate the NPC is a promising electrode material for sodium ion batteries.

Facile green synthesis of nitrogen-doped porous carbon and its use for electrocatalysis towards nitrobenzene and hydrazine

By using eco-friendly polydopamine as carbon and nitrogen precursor and commercial hydrophilic nano-CaCO3 as hard-template; a one step, cost-effective and green method to synthesize nitrogen-doped porous carbon (NPC) is presented. A series of NPC samples with different nitrogen contents have been reported. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectra (EDX), fourier transform infrared spectroscopy (IR), Raman spectroscopy, X-ray diffraction (XRD), nitrogen adsorption-desorption and X-ray photoelectron spectra (XPS) were employed for characterizations of NPC. The influence of BET surface area and different amounts of N-bonding configurations of NPC for the electrocatalysis towards nitrobenzene (NB) and hydrazine (N2H4) were investigated in detail. Results indicated that NPC with largest BET surface area and highest amounts of pyrrolic N and graphitic N showed improved electrocatalytic activity for NB and N2H4 in neutral solution.

Facile Synthesis of Nitrogen-doped Porous Carbon for Selective CO2 Capture

Solid-state post-combustion CO2 sorbents have certain advantages over traditional aqueous amine systems, including reduced regeneration energy since vaporization of liquid water is avoided, tunable pore morphology, and greater chemical variability. We report here an ordered mesoporous nitrogen-doped carbon made by the co- assembly of a modified-pyrrole and triblock copolymer through a soft-templating method, which is facile, economic, and fast compared to the hard-template approach. A high surface area mesoporous carbon was achieved, which is comparable to the silica counterpart. This porous carbon, with a Brunauer–Emmett–Teller (BET) specific surface area of 804.5 m2 g-1, exhibits large CO2 capacities (298 K) of 1.0 and 3.1 mmol g-1 at 0.1 and 1 bar, respectively, and excellent CO2/N2 selectivity of 51.4. The porous carbon can be fully regenerated solely by inert gas purging without heating. It is stable for multiple adsorption/desorption cycles without reduction in CO2 capacity. These desirable properties render the nitrogen-doped hierarchical porous carbon a promising material for post-combustion CO2 capture.

Facile synthesis of nitrogen-doped porous carbon for supercapacitors

A very simple, activation-free method for preparing nitrogen-doped porous carbon with high surface area for supercapacitors by direct pyrolysis of a nitrogen-containing organic salt, ethylenediamine tetraacetic acid (EDTA) disodium magnesium salt, in an inert atmosphere is presented. As the pyrolysis temperature increases from 500 to 900 °C, both the BET surface area and pore volume of the disodium magnesium EDTA-derived carbons increase and reach up to 1811 m2 g−1 and 1.16 cm3 g−1, respectively, while the nitrogen content decreases from 11.14 at.% to 1.13 at.%. The carbon obtained at a moderate pyrolysis temperature of 700 °C possesses a balanced surface area (1258 m2 g−1) and nitrogen content (5.43 at.%), exhibits high capacitance (281 F g−1), good rate capability (196 F g−1 at 20 A g−1) and cycle durability in 6 mol L−1 KOH aqueous electrolytes.