Nitrogen-doped Mesoporous Carbon Research Articles

A magnetic imprinted polymer nano-adsorbent with embedded quantum dots and mesoporous carbon for the microextraction of triazine herbicides

A magnetic molecularly imprinted polymer (MMIP) adsorbent incorporating amino-functionalized magnetite nanoparticles, nitrogen-doped graphene quantum dots and mesoporous carbon (MIP@MPC@N-GQDs@Fe3O4NH2) was fabricated to extract triazine herbicides from fruit juice. The embedded magnetite nanoparticles simplified the isolation of the adsorbent from the sample solution. The N-GQDs and MPC enhanced adsorption by affinity binding with triazines. The MIP layer provided highly specific recognition sites for the selective adsorption of three target triazines. The extracted triazines were determined by high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD). The developed method exhibited linearity from 1.5 to 100.0 µg L−1 with a detection limit of 0.5 µg L−1. Recoveries from spiked fruit juice samples were in the range of 80.1– 108.4 %, with a relative standard deviation of less than 6.0 %. The developed MMIP adsorbent demonstrated good selectivity, high extraction efficiency, ease of fabrication and use, and good stability.

Nitrogen-doped magnetic porous carbon nanospheres derived from dual templates-induced mesoporous polydopamine coated Fe3O4 for efficient extraction and sensitive determination of volatile nitrosamines by gas chromatography-mass spectroscopy

N-nitrosamines (NAs) are highly carcinogenic compounds commonly found in food, beverages, and consumer products. Due to their wide polarity range, it is challenging to find a suitable carbon adsorbent that can simultaneously adsorb and enrich both polar and nonpolar NAs with good recovery. In this study, nitrogen-doped magnetic mesoporous carbon nanospheres (M-MCN) were prepared and employed as an adsorbent for magnetic solid-phase extraction (MSPE) to extract and concentrate four NAs. The introduction of nitrogen functional groups enhanced the hydrophilicity of the carbon material, allowing M-MCN to achieve a balance between hydrophilicity and hydrophobicity, resulting in good recovery for both polar and nonpolar NAs. A method combining MSPE with gas chromatography-mass spectrometry (GC-MS) was developed for the determination of NAs in processed meat and alcoholic beverages. The method exhibited a good linear range (1-100 ng g-1, r2 > 0.9967) and trace-level detection (0.53-6.6 ng g-1). The recovery rates for the four NAs ranged between 85.7-110.7%, with intra-day precision expressed as relative standard deviation (RSD) between 4.1-10.7%, and inter-day precision between 4.8-12.9%. The results demonstrated not only good accuracy and precision but also provided a new adsorbent for the enrichment of trace-level NAs in processed meat and alcoholic beverage samples.

FeCo alloy nanoparticles supported on N-doped mesoporous carbon spheres for effective degradation of antibiotics and industrial dyes

Iron (Fe) is widely recognized for its effectiveness in the Fenton reaction and is commonly used in wastewater treatment. However, exploring other metals in similar Fenton-like reactions has been relatively limited. FeCo alloy nanoparticles (NPs), anchored on nitrogen-doped mesoporous carbon spheres (FeCo/NMCS), have been effectively synthesized and used as a Fenton-like catalyst in wastewater treatment under alkaline conditions. The NMCS exhibited spherical with an average diameter of 488.1 nm, while the FeCo alloy NPs, uniformly distributed over the NMCS, had an average diameter of 8.2 nm. The mesopores served as anchoring points for the NiCo alloy NPs, effectively preventing their possible agglomeration. The NMCS was composed of 3.91 wt% nitrogen. With 30 mg of FeCo/NMCS and 25 mM H2O2, more than 92% of tetracycline hydrochloride (TC) was degraded within 35 min at pH levels 7, 9, and 11. The remarkable degradation rate was attributed to the dual active sites present in the FeCo alloys. The rapid degradation of TC, even at pH 11, indicates the potential of FeCo/NMCS as a valuable solution for wastewater treatment under alkaline conditions. Industrial reactive (Y145, R195, B222A) and disperse dyes (O30, R167, B79) with a concentration of 10 ppm were degraded within 20 min when using 10 mg of the FeCo/NMCS catalyst and 25 mM H2O2 at pH 9. After five consecutive TC degradation cycles at pH 7 and 9, the FeCo/NMCS demonstrated consistent performance, emphasizing its reusability. FeCo/NMCS provides a promising solution to pollution control and wastewater treatment with stability, superior catalytic activity, magnetic separability, and recyclability.

Achieving unprecedented cyclability of flowless zinc-bromine battery by nitrogen-doped mesoporous carbon on thick graphite felt electrode

The flowless zinc-bromine battery (FLZBB) is non-flammable as it is based on an aqueous electrolyte and is considered an alternative to redox flow batteries because of its cost-effectiveness using a simple cell platform. However, it faces challenges related to self-discharge caused by the crossover of bromine (Br2) and polybromide anions (Brn+2-) formed at the positive electrode during the charging process. The self-discharge reaction consumes the charging active materials, thereby decreasing battery performance and lifespan. To address the critical issues, this study introduces the development of a revolutionary positive electrode: a nitrogen-doped mesoporous carbon-coated thick graphite felt (NMC/GF). This positive electrode effectively suppresses the crossover of active materials and prevents the self-discharge reaction. The mesopores, strategically embedded with nitrogen sites, serve as a stronghold, capturing and immobilizing bromine and polybromide anions, significantly reducing their undesirable effects. Furthermore, we enhanced the electrochemical performance of the NMC/GF electrode by modifying it to be ultrahydrophilic. Abundant oxygen and nitrogen functional groups were incorporated onto the electrode, resulting in an amplified affinity with the aqueous electrolyte. This modification led to improved bromine redox reaction kinetics. Demonstrating an excellent Coulombic efficiency surpassing 96 % and an energy efficiency of over 76 % at a current density of 20 mA cm−2 with a high-rate areal capacity of 2 mAh cm−2, this novel positive electrode achieves a previously unattained milestone; cyclability unprecedentedly extended to 10,000 cycles. The development of NMC/GF positive electrodes further advances the FLZBB system, and large-area scale-up research of these carbon electrodes makes looking forward to practical uses in energy storage systems.

Organic precursors for tailored synthesis of sulfur- and nitrogen-doped mesoporous carbons: a molecular design approach.

Insights into tailoring heteroatom-doped mesoporous carbon are provided for enhanced electrocatalytic properties. This study focuses on the design and synthesis of sulfur-doped mesoporous carbon using a sulfur-containing monomer with a chemical structure similar to dopamine. The resulting material achieves remarkable catalytic activity for the oxygen reduction reaction.

Controllable fabrication of N-doped carbon nanotubes coated Co4N nanoparticles to boost hydrogen evolution reaction

Transition metal nitrides (TMNs) have attracted great attention as ideal active materials in the field of electrocatalysts in recent years due to their excellent electrical conductivity, wide band gap and adjustable morphology. Pure phase Co4N nanoparticles encapsulated nitrogen-doped carbon (NC) nanotubes (Co4N@NC) were in-situ synthesized by one-pot method. In this paper, the morphology of carbon nanotubes is controlled by adjusting the pyrolysis time, so that more active sites are exposed on carbon nanotubes. Thus, the cobalt nitride catalyst with excellent catalytic performance for hydrogen evolution reaction (HER) in acidic electrolyte was obtained. In summary, due to the protection of mesoporous nitrogen-doped carbon to Co4N nanoparticles, large electrochemically active surface area, good conductivity and more exposed active sites, Co4N@NC possesses excellent HER performance in acidic electrolytes. The overpotential of Co4N@NC at the current density of 10 mA cm−2 is 117 mV (η10), and it shows long-term stability in 0.5 M H2SO4 solution for 50 h. This study provides a strategy for the development of catalysts for the controllable synthesis of high-performance transition metal nitrides.

Defect engineering enables an advanced separator modification for high-performance lithium-sulfur batteries

High-energy–density lithium-sulfur batteries have been rated as a promising, yet challenging, next-generation battery technology. Typically, the serious shuttle of polysulfide intermediates and sluggish solid–solid reaction kinetics often result in irreversibly sulfur loss, low Coulombic efficiency, and limited lifespan. Herein, we propose a facile and efficient separator modification strategy using a rationally designed sulfiphilic and lithiophilic mediator, i.e. in-situ confinement growth of oxygen-deficient TiO2-x nanoparticles within nitrogen-doped mesoporous carbon matrix to modulate the sulfur electrochemistry. The nanoscale defective catalyst within open mesoporous host affords favorable adsorption of polysulfides and catalytic conversion ability. Moreover, the versatile composite improves the electrolyte wettability and Li+ transfer kinetics and alleviates self-discharge behavior. Resultantly, the Li-S batteries using modified separator achieves significantly improved cycling stability with a low capacity decay of only 0.067% per cycle after 500 cycles at 2C. The defect engineering together with separator modification strategies enable efficient and durable Li-S batteries.

Metal-Free Nitrogen-Doped Mesoporous Carbons for the Mild and Selective Synthesis of Pyrroles from Nitroarenes via Cascade Reaction.

The cascade synthesis of pyrroles from nitroarenes is an attractive alternative strategy. However, metal catalysts and relatively high temperatures cover the existing reported catalytic systems for this strategy. The development of nonmetallic heterogeneous catalytic systems for the one-pot synthesis of pyrrole from nitroarenes under mild conditions is both worthwhile and challenging. Herein, we describe an exceptionally efficient method for the synthesis of N-substituted pyrroles by the reductive coupling of nitroarenes and diketones over heterogeneous metal-free catalysts under mild conditions. Nonmetallic NC-X catalysts with high activity were prepared from the pyrolysis of well-defined ligands via simple sacrificing hard template methods. Hydrazine hydrate, formic acid, and molecular hydrogen can all be used as reducing agents in the hydrogenation/Paal-Knorr reaction sequence to efficiently synthesize various N-substituted pyrroles, including drugs and bioactive molecules. The catalytic system was featured with good tolerance to sensitive functional groups and no side reactions such as dehalogenation and aromatics hydrogenation. Hammett correlation studies have shown that the electron-donating substituents are beneficial for the one-pot synthesis of N-substituted pyrroles. The results established that the outstanding performance of the catalyst is mainly attributed to the contribution of graphitic N in the catalyst as well as the promotion effect of the mesoporous structure on the reaction.

Nitrogen-doped mesoporous carbon spheres decorated with NiCo alloy nanoparticles for high-performance electrochemical supercapacitors

Nitrogen-doped mesoporous carbon spheres (NMCSs) decorated with NiCo alloy nanoparticles (NiCo/NMCS) were prepared and examined for their prospective role as high-performance electrode materials. The average size and BET surface of the NMCSs are 488.1 nm and 660.9 m2g−1. The N content of the NMCSs and NiCo/NMCS-50 (NMCSs with 50 wt% of NiCo alloy nanoparticles (NPs)) was 1.49 wt% and 2.9 wt%, respectively. The NiCo alloy NPs, with an average diameter of 9.6 nm, were evenly incorporated into NMCSs. The NiCo/NMCS-50 exhibited a specific capacitance of 585 F g−1 when tested in a 6 M KOH solution at a current density of 1 A/g. The superior electrochemical performance of NiCo/NMCS-50 is attributed to the synergistic effect of mesoporous carbon structure and NiCo alloy NPs by improving redox-related mass transport and electron transfer. Symmetric supercapacitor devices assembled using two NiCo/NMCS-50 electrodes had a maximum energy density of 30.0 Wh kg−1 at a power density of 187.5 W kg−1 with notable cycling stability, maintaining 60.1 % of capacitance, up to 5,000 cycles. These results suggest that NiCo/NMCS composites have significant potential for utilization in high-energy storage applications.

Encapsulating Sulfur into a Gel-Derived Nitrogen-Doped Mesoporous and Microporous Carbon Sponge for High-Performance Lithium-Sulfur Batteries.

The practical application of Li-S batteries (LSBs) has long been impeded by the inefficient utilization of sulfur and slow kinetics. Utilizing conductive carbonaceous frameworks as a host scaffold presents an efficient and cost-effective approach to enhance sulfur utilization for redox reactions in LSBs. However, the interaction of pure carbon materials with lithium polysulfide intermediates (LiPSs) is limited to weak van der Waals forces. Hence, the development of an economical method for synthesizing heteroatom-doped carbon materials for sulfur fixation is of paramount importance. In this study, we introduce a hierarchical porous nitrogen-doped carbon sponge (NPCS) with an exceptionally high BET surface area of 3182.2 m2 g-1, achieved through a facile template-assisted polymerization method. The incorporation of inorganic salts, free radical polymerization, and deuteric freeze-drying techniques facilitates the formation of hierarchical pores within the NPCS. After sulfur fixation, the resulting S/NPCS electrode demonstrates remarkable electrochemical performance in LSBs. Specifically, it achieves an 80% sulfur utilization rate, maintains a high reversible specific capacity of 400 mA h g-1 even after 600 cycles at a demanding current density of 5.0 A g-1, and exhibits superior rate capability. It is believed that this work will inspire the rational design of cost-effective carbon-based electrodes for high-performance LSBs.

Nitrogen-doped carbon quantum dots as a novel treatment for black fungal bone infections (Mucormycosis): in vitro and in vivo study

Most fungal bone and joint infections (arthritis) are caused by Mucormycosis (Mucor indicus). These infections may be difficult to treat and may lead to chronic bone disorders and disabilities, thus the use of new antifungal materials in bone disorders is vital, particularly in immunocompromised individuals, such as those who have contracted coronavirus disease 2019 (COVID-19). Herein, we reported for the first time the preparation of nitrogen-doped carbon quantum dots (N/CQDs) and a nitrogen-doped mesoporous carbon (N/MC) using a quick micro-wave preparation and hydrothermal approach. The structure and morphology were analysed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and surface area analyser. Minimum inhibitory concentration (MIC), disc diffusion tests, minimum fungicidal concentration (MFC) and antifungal inhibitory percentages were measured to investigate the antifungal activity of N/CQDs and N/MC nanostructures. In addition to the in vivo antifungal activity in rats as determined by wound induction and infection, pathogen count and histological studies were also performed. According to in vitro and in vivo testing, both N/CQDs with small size and N/MC with porous structure had a significant antifungal impact on a variety of bone-infecting bacteria, including Mucor infection. In conclusion, the present investigation demonstrates that functional N/CQDs and N/MC are effective antifungal agents against a range of microbial pathogenic bone disorders in immunocompromised individuals, with stronger and superior fungicidal activity for N/CQDs than N/MC in vitro and in vivo studies.

Degradation of Sulfamethoxazole by Activation of Persulfate Based on Nitrogen-Doped Mesoporous Carbon

Degradation of Sulfamethoxazole by Activation of Persulfate Based on Nitrogen-Doped Mesoporous Carbon

Synergistic vacancy engineering of Co/MnO@NC catalyst for superior oxygen reduction reaction in liquid/solid zinc-air batteries

The pursuit of efficient and economically viable catalysts for liquid/solid-state zinc-air batteries (ZABs) is of paramount importance yet presents formidable challenge. Herein, we synthesized a vacancy-rich cobalt/manganese oxide catalyst (Co/MnO@NC) stabilized on a nitrogen-doped mesoporous carbon (NC) nanosphere matrix by leveraging hydrothermal and high-temperature pyrolysis strategy. The optimized Co/MnO@NC demonstrates fast reaction kinetics and large limiting current densities comparable to commercial Pt/C in alkaline electrolyte for oxygen reduction reaction (ORR). Moreover, the Co/MnO@NC serves as an incredible cathode material for both liquid and flexible solid-state ZABs, delivering impressive peak power densities of 217.7 and 63.3 mW cm−2 and robust long-term stability (459 h), outperforming the state-of-the-art Pt/C and majority of the currently reported catalysts. Research indicates that the superior performance of the Co/MnO@NC catalyst primarily stems from the synergy between the heightened electrical conductivity of metallic Co and the regulatory capacity of MnO on adsorbed oxygen intermediates. In addition, the abundance of vacancies regulates the electronic configuration, and superhydrophilicity facilitates efficient electrolyte diffusion, thereby effectively ensuring optimal contact between the active site and reactants. Besides, the coexisting NC layer avoids the shedding of active sites, resulting in high stability. This work provides a viable approach for designing and advancing high-performance liquid/solid-state ZABs, highlighting the great potential of energy storage technology.

Effects of the chemical states of N sites and mesoporosity of N-doped carbon supports on single-atom Ru catalysts during CO2-to-formate conversion

This study explores the fabrication and characterization of mesoporous nitrogen-doped carbon replicas (MNCs) as Ru catalyst supports for CO2 hydrogenation to formate. MNC supports with a cubic Ia3d-like structure were successfully synthesized from a KIT-6 template. The mesoporosity, N content, and N states in the MNCs differed according to the precursor type, which substantially influenced the stability of single-atom Ru catalysts during CO2 conversion. In hydrogenation tests, the Ru/MNC prepared using acrylonitrile precursor (Ru/MNC-A) demonstrated the best stability, whereas the Ru/MNCs prepared using pyrrole and melamine exhibited low activity owing to Ru agglomeration and limited reactant diffusion, respectively. The excellent stability of Ru/MNC-A resulted from Ru migration and rearrangement, as evidenced by near edge X-ray absorption fine structure analyses. Ru/MNC-A and Ru/MNC-A-400 achieved an outstanding turnover number of 69,000 in CO2 hydrogenation over 72 h. Remarkably, the Ru/MNC-A catalyst demonstrated exceptional stability, attaining a TON of 315,840 over 360 h.

Rational design of p-ZnS@CN with 3D interconnected hierarchical pore structure through pyrolysis of an organic hybrid zinc thiocyanide for electrochemical lithium storage

3D interconnected porous carbon-coupled metal-sulfide composites have been demonstrated as promising lithium storage materials owing to their large surface areas as well as the acceleration effect to electrochemical kinetics. However, constructing these materials with ordered hierarchical pore structure is still a challenge. To address this issue, we found that the crystals of an organic hybrid zinc thiocyanide [Zn(NCS)2(phen)2] (phen = 1,10-phenanthroline) could become a fluid at 400 °C, and during the melting process, the phen ligand was simulatneously carbonized to form nitrogen-doped carbon materials, while the Zn(NCS)2 species were converted into ZnS quantum dots. This property could allow us to employ a hard template strategy for preparation of a porous p-ZnS@CN composite featuring 3D interconnected hierarchical structure, namely employing SiO2 nanospheres as sacrificial template and [Zn(NCS)2(phen)2] as precursor and thermal treatment this mixture at 400 °C. The as-obtained p-ZnS@CN (p = porous structure, CN = nitrogen-doped carbon) composite possesses ordered macro- and mesoporous nitrogen-doped carbon structures, where the ZnS quantum dots are embedded in. Due to their structural features, p-ZnS@CN showed a superior lithium storage performance in comparison with ZnS nanoparticles. The well-defined 3D interconnected hierarchical pore structure not only enhances the efficiency of lithium-ion diffusion, but also offers ample void space to buffer the volume expansion during lithiation. Given the diversity of crystalline organic hybrid metal thiocyanates, this work opens a new avenue of preparing 3D interconnected porous carbons-coupled metal-sulfide composites.

Metal-organic framework-derived cation regulation of metal sulfides for enhanced oxygen evolution activity

Heteroatom doping serves as an important strategy to improve the oxygen evolution reaction (OER) activity of transition-metal compounds, while the investigation of intrinsic active sites and mechanisms remains insufficient. In this work, a facile cation regulation strategy is reported to boost the OER activity of metal sulfides via pyrolysis of the Ni-Co bimetallic metal-organic framework. The obtained Ni-substituted CoS nanoparticles on nitrogen-doped mesoporous carbon (Ni-CoS/NC) catalyst achieves a current density of 10 mA cm−2 at a small overpotential of 270 mV with a Tafel slope of 37 mV dec−1 in 1.0 mol L−1 KOH. Through a combination of spectroscopy study and theoretical computations, the activity origin is revealed at the atomic level. The CoxNi1–xOOH serves as the real active site for the OER generated by the Ni-CoS/NC reconstruction under oxidation potential during OER. The Ni substitution results in a strong electronic interaction between the two metals, thus generating more negatively charged Co atoms and more positively charged Ni atoms in the electrocatalyst. The metal sites with regulated electronic structure exhibit enhanced surface adsorption of OOH* and reduce the OER overpotential. Meanwhile, the conductive porous carbon scaffold facilitates electron transfer, mass diffusion, and the accessibility of active sites. This work not only provides a feasible cation regulation strategy for the design of high-performance electrocatalysts for low-cost energy storage and conversion systems, but also yields fresh insight into the activity enhancement mechanisms and intrinsic active sites.

One-Pot Synthesis of Ultra-Small Pt Nanoparticles-Loaded Nitrogen-Doped Mesoporous Carbon Nanotube for Efficient Catalytic Reaction.

In this study, Pt nanoparticles-loaded nitrogen-doped mesoporous carbon nanotube (Pt/NMCT) was successfully synthesized through a polydopamine-mediated "one-pot" co-deposition strategy. The Pt source was introduced during the co-deposition of polydopamine and silica on the surface of SiO2 nanowire (SiO2 NW), and Pt atoms were fixed in the skeleton by the chelation of polydopamine. Thus, in the subsequent calcination process in nitrogen atmosphere, the growth and agglomeration of Pt nanoparticles were effectively restricted, achieving the in situ loading of uniformly dispersed, ultra-small (~2 nm) Pt nanoparticles. The method is mild, convenient, and does not require additional surfactants, reducing agents, or stabilizers. At the same time, the use of the dual silica templates (SiO2 NW and the co-deposited silica nanoclusters) brought about a hierarchical pore structure with a high specific surface area (620 m2 g-1) and a large pore volume (1.46 cm3 g-1). The loading process of Pt was studied by analyzing the electron microscope and X-ray photoelectron spectroscopy of the intermediate products. The catalytic performance of Pt/NMCT was investigated in the reduction of 4-nitrophenol. The Pt/NMCT with a hierarchical pore structure had an apparent reaction rate constant of 0.184 min-1, significantly higher than that of the sample, without the removal of the silica templates to generate the hierarchical porosity (0.017 min-1). This work provides an outstanding contribution to the design of supported noble metal catalysts and also highlights the importance of the hierarchical pore structure for catalytic activity.

Nitrogen-doped hollow mesoporous carbon spheres for efficient oxygen reduction

Extensive investigations have been devoted to nitrogen-doped carbon materials as catalysts for the oxygen reduction reaction (ORR) in various conversion technologies. In this study, we introduce nitrogen-doped carbon materials with hollow spherical structures. These materials demonstrate significant potential in ORR activity within alkaline media, showing a half-wave potential of 0.87 V versus the reversible hydrogen electrode (RHE). Nitrogen-doped hollow carbon spheres (N-CHS) exhibit unique characteristics such as a thin carbon shell layer, hollow structure, large surface area, and distinct pore features. These features collectively create an optimal environment for facilitating the diffusion of reactants, thereby enhancing the exposure of active sites and improving catalytic performance. Building upon the promising qualities of N-CHS as a catalyst support, we employ heme chloride (1 wt%) as the source of iron for Fe doping. Through the carbonization process, Fe-N active sites are effectively formed, displaying a half-wave potential of 0.9 V versus RHE. Notably, when implemented as a cathode catalyst in zinc-air batteries, this catalyst exhibits an impressive power density of 162.6 mW cm−2.

2D N-doped layered mesoporous carbon sheets for high-performance electrochemical hydrogen storage

The rapid growth in energy demands and environmental concerns have drawn great attention to the development of new functional materials for sustainable energy technologies. As an emerging material, mesoporous carbon-based materials exhibit unique properties and have been considered promising candidates for electrochemical hydrogen storage applications. However, pure mesoporous carbon as electrode material may suffer from sluggish electrolyte transportation kinetic and poor hydrophilicity. Two-dimensional layered structure with high exposure area and nitrogen doping, which provides the improved accessibility of ions as well as the hydrophilicity of carbon materials, can cope with these two challenges. Here, the nitrogen-doped layered mesoporous carbon sheets, prepared by the double-hard-template route, were characterized using various technologies and investigated the electrochemically stored hydrogen energy properties. The results exhibit that hydrogen storage can be achieved around 104 mAh g−1 at 100 mA g−1, and the capacity retention was 85.4% at 2 A g−1. Moreover, it also displays superior cycling stability with a retention of 98% upon 300 cycles. According to the obtained results, the layered mesoporous carbon sheets demonstrated suitable capacity as a potential and promising active material for hydrogen-proton-related devices.

Preparation of dispersed hollow carbon spheres assisted by silica/carbon shell isolation for supercapacitors

Nitrogen-doped mesoporous hollow carbon spheres are crucial in energy storage and the strategy of converting the inexpensive polymer polyacrylonitrile (PAN) into hollow carbon spheres needs to be improved. In this study, polystyrene/polyacrylonitrile (PSPAN) composite spheres were subjected to silica/carbon shell isolation to prepare nitrogen-doped hollow carbon spheres. In the carbonization process, the pyrolysis of PSPAN lead to the cavity due to the total decomposition behavior of PS. Due to the isolation of silica/carbon shells, the formation of a molten state during the pyrolysis process of PAN can be effectively prevented, thus avoiding the agglomeration of carbon spheres, and obtaining dispersed and regular hollow carbon spheres. The pore structure and specific surface area of the material were adjusted by hydrolyzing tetraethyl orthosilicate on the template surface and introducing dopamine for polymerization after different times. The hollow structure, nitrogen doping characteristics and abundant mesopores endow the NHCS with high performance in supercapacitor.