N-doped Hierarchical Porous Carbon Research Articles

N-Doped hierarchical porous carbon nanoscrolls towards efficient oxygen reduction reaction in Zn–air batteries via interior and exterior modifications

Etched EN-PCNS obtained using the combination of an in situ sacrificial template method and an NH3 etching method possesses a unique hierarchical porous morphology and controllable structure and composition, thus leading to an outstanding ORR performance in Zn–air batteries.

Highly reversible aluminium–sulfur batteries obtained through effective sulfur confinement with hierarchical porous carbon

A N-doped hierarchical porous carbon material can effectively regulate the electrochemical reactions of S for high-capacity and high-reversibility Al–S batteries. The dominant discharge product was explicitly demonstrated to be tetra-coordinated Al2S3.

Ferrocene-crosslinked polypyrrole hydrogel derived Fe–N-doped hierarchical porous carbon as an efficient electrocatalyst for pH universal ORR and Zn–air batteries

A Fe–N-doped catalyst (PF-800), prepared via pyrolysis of ferrocene-crosslinked polypyrrole hydrogel, shows impressive activity for ORR in various pH. Further Zn–air battery using PF-800 present high energy density and excellent long-term stability.

3D hierarchical porous N-doped carbon quantum dots/vanadium nitride hybrid microflowers as a superior electrode material toward high-performance asymmetric capacitive deionization

3D hierarchical porous NCQDs/VN hybrid microflowers were first demonstrated as an advanced electrode for an asymmetric capacitive deionization of saline water.

Carbon coated SiO nanoparticles embedded in hierarchical porous N-doped carbon nanosheets for enhanced lithium storage

Carbon coated SiO nanoparticles embedded in N-doped carbon nanosheets were synthesized via a scalable and cost-effective route, and exhibited enhanced cyclability and rate capability as an anode for lithium-ion batteries.

Highly active sites of Pt/Er dispersed N-doped hierarchical porous carbon for trifunctional electrocatalyst

Fabrication of Pt alloy with controlled morphology and size has drawn an attractive attention in developing active electrocatalysts for fuel cell and water splitting application. However, the effectively controlled synthesis strategy and morphology on N-doped carbon structure is still a challenging issue. Herein, a facile strategy for uniform dispersion of active sites of Pt/Er on the hierarchical N-doped carbon structure through pyrolysis in innert atmosphere is addopted. The developed product of Pt-Er@PCN-900 has exhibited efficacious trifunctional catalytic activity for hydrogen/oxygen evolution as well as oxygen reduction reaction. Comparatively, Pt-Er@PCN-900 with 8% Pt presents excellent performance than commercial 20%Pt/C. The present work highlights the importance of the rationalized dispersion of Pt/Er active sites for the future large-scale commercial applications of fuel cell and water splitting.

Enhanced Electrochemical Performance by In Situ Phase Transition from SnS2 Nanoparticles to SnS Nanorods in N-Doped Hierarchical Porous Carbon as Anodes for Lithium-Ion Batteries

Tin sulfides have attracted great attention as promising anode materials for lithium-ion batteries due to their high theoretical specific capacity. However, the rapid capacity decay, resulting from...

Sustainable N-doped hierarchical porous carbons as efficient CO2 adsorbents and high-performance supercapacitor electrodes

Herein, a series of ACs are prepared with and without nitrogen doping at two different activation temperatures i.e., 800 °C and 900 °C. As-prepared ACs possess a high surface area (1142 - 2211 m2 g−1), large total pore volume (0.641 - 2.018 cm3 g−1), and a well-developed porous structure. At 1 bar, ACs demonstrate a remarkable CO2 uptake of 2.86 - 6.90 mmol g−1 at 273 K and 2.22 - 4.71 mmol g−1 at 298 K. This is attributed to the large ultra-micropore volume of pore size (< 0.73 nm), a prerequisite for achieving high CO2 adsorption. Finally, ACs based electrodes used for supercapacitors display high specific capacitance (100 - 204 Fg−1 at 0.5 Ag−1), and outstanding stability (∼ 92 % capacity retained even after 1000 cycles). It is shown that glucose-derived carbon precursor activated by potassium hydroxide at 900 °C denoted as “CK-900” proves to be the best sample for CO2 adsorption due to its narrow pore size, whereas glucose derived carbon precursor with melamine (acts as a nitrogen doping material) activated by potassium hydroxide at 900 °C denoted as “CNK-900” exhibits the best supercapacitive characteristics owing to its wider pore size distribution, high pore volume, and optimum nitrogen content. The remarkable CO2 uptake and energy storage capacities are attributed to high surface area, optimum nitrogen doping, and micro-mesopores volume of ACs framework.

Synthesis and processing optimization of N-doped hierarchical porous carbon derived from corncob for high performance supercapacitors

• Porous carbon has been synthesized by pyrolysis methods using corncob as precursor. • Nitrogen-doped hierarchical porous carbon shows high gravimetric capacitances. • The symmetric device shows high energy density and good electrochemical stability. • This method holds great promise for low-cost and high performance supercapacitors. In this paper, N-doped hierarchical porous carbon-based supercapacitor electrode materials have been synthesized by means of pyrolysis methods using corncob, KOH and urea as biomass sources, activator and nitrogen source, respectively. The influence of carbonization temperature on the morphology and structure and N doping content on supercapacitor performance of corncob derived porous carbons has been investigated systematically. The specific capacitance of sample with carbonization temperature at 800 °C and urea: corncob mass ratio of 4:3 reaches 382.6 F/g at 0.5 A/g, and still maintains as high as 232.7 F/g at high current density of 20 A/g. The symmetric supercapacitor achieves a high energy density of 18.84 Wh/kg at power density of 149.36 W/kg in 6 M KOH aqueous electrolyte. It also shows excellent cycling stability with a 95.16% capacitance retention after 10,000 cycles. The results demonstrate that these as-prepared corncob-derived activated carbons have a great prospect in low-cost and high-performance supercapacitors.

Transforming waste sugar solution into N-doped hierarchical porous carbon for high performance supercapacitors in aqueous electrolytes and ionic liquid

Waste sugar solution is a by-product in the process of manufacturing vitamin C. Nowadays, the unused industrial waste residues are transformed into high efficient energy storage devices, such as supercapacitors electrodes, which are worth exploring because they are consistent with the concept of green and sustainable development. In this paper, a nitrogen-doped hierarchical porous carbon are obtained via pre-carbonization and KOH activation. The as-prepared material, possessed proper pore size distribution, large specific surface area and nitrogen-doping, exhibits good electrochemical performance, such as a high specific capacitance of 342 F g−1 (0.1 A g−1), good stability with 95% capacitance retention after 15,000 cycles in 6 M KOH. Moreover, the supercapacitors deliver a high energy density of 25.6 and 65.9 W h kg−1 in the 1 M Na2SO4 and EMIMBF4, respectively. The good electrochemical performance illustrates that the nitrogen-doped hierarchically porous carbon derived from the waste sugar solution is a potential candidate for energy storage.

In situ synthesis of Co3O4 nanoparticles confined in 3D nitrogen-doped porous carbon as an efficient bifunctional oxygen electrocatalyst

The rational exploitation of non-precious metal catalyst with high activity, strong durability and low cost for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is of vital importance for metal–air batteries. Herein, a composite of Co3O4 nanoparticles confined in three-dimensional (3D) N-doped porous carbon (Co-NpCs) was prepared by a simple freeze-drying and in situ pyrolysis method. The effect of different dosages of Co(NO3)2 on the catalytic performance was discussed. The Co-NpC-12% exhibits the best catalytic performance (E1/2 = 0.78 V, better stability than 20% Pt/C) in ORR and in OER among all the as-synthesized samples. Furthermore, it also exhibits the best bifunctional activity (ΔE = 0.849 V). The excellent properties of Co-NpCs are mainly due to the synergy between Co3O4 and carbon. Firstly, a high Co3O4 loading amount can boost the defect level of the N-doped hierarchical porous carbon and expose more active sites. Secondly, the unique in situ pyrolysis guarantees a large-area contact between Co3O4 and carbon as well as a strong C–O–Co bonding, which promotes charge transfer, avoids the peeling of Co3O4 nanoparticles and effectively improves the stability of the material. This work is expected to offer a feasible strategy to produce metal oxide/carbon nanocomposite and push forward the development of bifunctional electrocatalyst with high activity and stability.

Hierarchical porous carbon doped with high content of nitrogen as sulfur host for high performance lithium–sulfur batteries

The applications of Li S batteries are restricted by the issues of the imperfect conductivity and severe volumetric change of active materials together with shuttle effect of lithium polysulfides, which requires a kind of material with appropriately multifunctional structure as sulfur host. Herein, an N–doped hierarchical porous carbon composite is synthesized via a high temperature carbonization method. The N–doped hierarchical porous carbon with a large number of micropores, mesopores and macropores provides the abundant interconnected network matrixes and high specific surface area, thus guaranteeing a high sulfur loading, and adapting the volumetric expansion during the lithium intercalation process. The macropore channels and conductive interconnected networks can accelerate the diffusion of electrons/ions among the cathode. Moreover, the mesopores and micropores besides the high amount N–doping accommodate high–level sulfur loading and immobilize lithium polysulfides via physical absorption and chemical confinement. The as–prepared N–doped hierarchical porous carbon compounded with sulfur as a cathode delivers a satisfactory initial capacity of 1285 mAh g −1 at 0.2 A g −1 and a reversible capacity of 517 mAh g −1 at 0.5 A g −1 over 1000 cycles, illustrating the improved electrochemical performances of the cathode. The high temperature carbonization method provides a new way to construct the hierarchical porous structured carbon with chemical doping. • N-doped hierarchical porous carbon was developed. • It has a large number of micropores, mesopores and macropores. • N-doped hierarchical porous carbon exhibit high capacity and rate performance. • High performance is ascribed to the porous hierarchical structure and N doping.

One-Step Synergistic Effect to Produce Two-Dimensional N-Doped Hierarchical Porous Carbon Nanosheets for High-Performance Flexible Supercapacitors

Porous carbon-based supercapacitor has been regarded as a promising candidate for powering wearable electronics. To improve its energy density and mechanical flexibility, great efforts have been ma...

3D hierarchical porous N-doped carbon nanosheets/MgFe2O4 composite as anode material with excellent cycling stability and rate performance

3D hierarchical porous N-doped carbon nanosheets/MgFe2O4 (MFO/NPC) was designed and synthesized successfully as the anode materials for lithium ion batteries by freeze-drying technology with dual salt templates and subsequent in-situ solvent thermal method. Its specific capacity rises steadily to 1337.7 mAh g−1 at the 260th cycle with the initial coulombic efficiency of 78.3% (0.5 A g−1). And the capacity remains at 534.1 mAh g−1 even after 1500 cycles at the current density of 5 A g−1. The excellent electrochemical performances can be attributed to the 3D conductive carbon skeleton and the chemical interaction between MFO and the doped N element.

Edge-Plane Exposed N-Doped Carbon Nanofibers Toward Fast K-Ion Adsorption/Diffusion Kinetics for K-Ion Capacitors

Sluggish kinetics severely limit the development of potassium-ion hybrid capacitors (PIHCs). Exposing active sites is recognized as an ideal strategy to resolve this issue, but the corresponding ma...

High N-doped hierarchical porous carbon networks with expanded interlayers for efficient sodium storage

Sodium-ion batteries (SIBs) have been attracting considerable attention as a promising candidate for large-scale energy storage because of the abundance and low-cost of sodium resources. However, lack of appropriate anode materials impedes further applications. Herein, a novel self-template strategy is designed to synthesize uniform flowerlike N-doped hierarchical porous carbon networks (NHPCN) with high content of N (15.31 at.%) assembled by ultrathin nanosheets via a self-synthesized single precursor and subsequent thermal annealing. Relying on the synergetic coordination of benzimidazole and 2-methylimidazole with metal ions to produce a flowerlike network, a self-formed single precursor can be harvested. Due to the structural and compositional advantages, including the high N doping, the expanded interlayer spacing, the ultrathin two-dimensional nano-sized subunits, and the three-dimensional porous network structure, these unique NHPCN flowers deliver ultrahigh reversible capacities of 453.7 mAh·g−1 at 0.1 A·g−1 and 242.5 mAh·g−1 at 1 A·g−1 for 2,500 cycles with exceptional rate capability of 5 A·g−1 with reversible capacities of 201.2 mAh·g−1. The greatly improved sodium storage performance of NHPCN confirms the importance of reasonable engineering and synthesis of hierarchical carbon with unique structures.

Acetone dissolution to prepare N-doped hierarchical porous carbon for supercapacitor

The hierarchical porous carbon (HPC) materials have rich porous structure, high specific surface area and reasonable porosity for a wide range of applications in many fields, such as catalysis, adsorption, and energy storage, etc. Although some synthetic strategies have been developed, efficient preparing HPC materials remains challenging. In this work, we propose a method to prepare N-doped hierarchical porous carbon (NHPC) by acetone dissolution following co-assembly process. 1-Alkyl-3-methyl imidazole bromide ([C18Mim]Br), tetraethyl orthosilicate (TEOS) and resorcinol-formaldehyde were co-assembled to form a pleated sheet composite material, where [C18Mim]Br induced formation of the sheet structure and also led to nitrogen doping in the carbon skeleton. TEOS created a mesoporous structure and increased specific surface area, while acetone dissolved the oligomer of the resin, creating a macroporous structure, but destroying the morphology of the sheet. At an appropriate amount of acetone, the resulting NHPC exhibits the hierarchical porous structure, high specific surface area and N-doping characteristics. When used as a supercapacitor material, NHPC exhibits the specific capacitance is as high as 241 F g−1 at 1 A g−1. Furthermore, the symmetric supercapacitor manufactured with NHPC has a power density of 4.1 kW kg−1, an energy density of 2.56 Wh kg−1, and demonstrates excellent cycle stability of up to 92.82%, exhibiting the potential as good supercapacitor materials.

An efficient pH-universal electrocatalyst for oxygen reduction: defect-rich graphitized carbon shell wrapped cobalt within hierarchical porous N-doped carbon aerogel

The design and facile synthesis of active, robust, cheap, and earth-abundant electrocatalysts to replace precious Pt catalysts is highly desirable for the cathodic oxygen reduction reaction (ORR) in fuel cells and rechargeable metal batteries. However, maximizing the catalytic activity and stability of the electrocatalysts in catalyzing ORR is significantly important but still remains challenge. To address this issue, we herein reported an effective strategy that fabricate the cobalt nanoparticles encapsulated with defect-rich graphitized carbon shell in the hierarchical porous N-doped carbon aerogel (Co/NCA), which can simultaneously enhance the electrochemical stability while boosting the electrocatalytic activity for ORR. The desirable combination of the Co nanoparticles encapsulated with defect-rich graphitic carbon shells coupling with Co−Nx sites, the large accessible surface-active sites, and the hierarchical porous structure give rise to the superior electrocatalytic activity and stability for ORR in wide pH range. As expect, the as-obtained catalyst exhibits high efficiency for ORR with an onset potential of 0.95 V (versus reversible hydrogen electrode, vs. RHE) and a half-wave potential of 0.83 V in 0.1 M KOH, comparable to the commercial Pt/C. Importantly, the catalyst also provides excellent ORR properties in acidic and neutral media with almost a 4e− pathway and superior durability and methanol tolerance, showing a potential as electrocatalysts for practical applications.

Aerosol-assisted preparation of N-doped hierarchical porous carbon spheres cathodes toward high-stable lithium-ion capacitors

Lithium-ion capacitors (LICs) are gradually emerging as one of the most indispensable hybrid energy storage devices. However, it is one main challenge to evade the mismatch of electrochemical kinetics and specific capacity between cathode and anode in LICs. Herein, we have proposed an efficient strategy to prepare the nitrogen-doped hierarchical porous carbon spheres (NHPCS) as cathode, which is synthesized by a simple aerosol-spraying pyrolysis using the low-cost phenolic resin as carbon source without any other catalyst or hard template. The NHPCS exhibits porous nanospheres structure with an appropriate nitrogen doping level (3.65 at.%). Benefitting from the two-pronged strategy of N-doped feature and nanostructure engineering, NHPCS achieves a high specific capacity of 74 mAh g−1 at a current density of 0.1 A g−1 and remains 86.5% of initial capacity even being subjected to a high rate of 50-fold. Furthermore, a high-performance LIC has been developed by coupling NHPCS cathode and hard carbon anode, which delivers a maximum energy density of 151 Wh kg−1 and excellent cycle stability (96.3% capacity retention after 3000 cycles). Significantly, such designed porous carbon could not only be convenient for scalable production, but also be served for many other energy storage devices. We have presented a larger-scale spray pyrolysis strategy to prepare nitrogen-doped hierarchical porous carbon spheres (NHPCS). A high-stable lithium-ion capacitor has been constructed by coupling NHPCS cathode with hard carbon anode, which exhibits a maximum energy density of 151 Wh kg−1 and capacity retention of 96.3% over 3000 cycles, showing great potential for the next-generation energy storage application.

Preparation and adsorption property of novel inverse-opal hierarchical porous N-doped carbon microspheres

The design of pore structure is the key factor for the performance of porous carbon spheres. In this work, novel micron-sized colloidal crystal microspheres consisting of fibrous silica (F-SiO2) nanoparticles are firstly prepared by water-evaporation-induced self-assembly of F-SiO2 nanoparticles in the droplets of an inverse emulsion system to be used as sacrificial templates. Acrylonitrile (AN) was infiltrated in the voids of the F-SiO2 colloidal crystal microspheres, and in-situ induced by 60Co γ-ray to polymerize into polyacrylonitrile (PAN). After the PAN-infiltrated F-SiO2 colloidal crystal microspheres were carbonized and etched with HF solution, novel micron-sized inverse-opal N-doped carbon (IO-NC) microspheres consisting of hollow carbon nanoparticles with a hierarchical macro/meso-porous inner surface were obtained. The IO-NC microspheres have a specific surface area as high as 266.4 m2/g and a molar ratio of C/N of 5. They have a good dispersibility in water, and show a high adsorption capacity towards rhodamine B (RhB) up to 137.28 mg/(g microsphere). This work offers a way to obtain novel micron-sized hierarchical macro/meso-porous N-doped carbon microspheres, which opens a new idea to prepare high-performance hierarchical porous carbon materials.