High-catalytic high-performance carbon nanocomposite material, preparation method and application

Abstract

This application relates to the field of carbon nanomaterials technology, and particularly to a high-catalytic-performance carbon nanocomposite material, its preparation method, and its applications. The composite material includes: a nitrogen-doped ordered mesoporous carbon substrate; cobalt nanoparticles generated in situ and loaded onto the surface and pores of the ordered mesoporous carbon substrate; and high-entropy alloy nanoparticles loaded onto the ordered mesoporous carbon substrate and the cobalt nanoparticles. The cobalt nanoparticles serve as nucleation centers, and the cobalt nanoparticles diffuse and alloy with other added metal elements, resulting in the cobalt element in the high-entropy alloy nanoparticles originating from the cobalt nanoparticles themselves. Through a multi-level synergistic design of the nitrogen-doped carbon substrate, cobalt nanoparticles, and high-entropy alloy, the application addresses the problems of poor catalytic performance, low utilization of active sites, and poor structural synergy in traditional carbon-based materials. It also addresses the high cost and low yield of existing materials, making it difficult to simultaneously achieve high catalytic activity and excellent structural and functional properties.

Description

Technical Field

[0001] This application relates to the field of carbon nanomaterials technology, and in particular to a high-catalytic-performance carbon nanocomposite material, its preparation method, and its application. Background Technology

[0002] Carbon nanomaterials, due to their abundant reserves, excellent conductivity, large specific surface area, and flexible control, combined with high stability and high strength, have become ideal catalytic supports in fields such as electrocatalysis and energy conversion, giving rise to various types such as activated carbon and graphene. Among them, biomass carbon, as a novel carbon material, not only retains its porous structure and excellent conductivity compared to traditional carbon materials, but also possesses unique advantages such as abundant active sites, low cost, and good biocompatibility, providing a new direction for the low-cost and green development of carbon-based composite materials. Carbon nanocomposites, with their tunable surface chemistry and acid and alkali resistance and high-temperature stability, have further broadened their application prospects in catalysis and advanced engineering materials, such as ultra-high performance concrete (UHPC). However, existing materials still face problems such as insufficient utilization of active sites, poor structural synergy, and difficulty in achieving a balance between catalysis and structural / functional enhancement applications.

[0003] Compared to noble metals, transition metals have significant advantages in terms of abundance and low cost. Elements such as iron, cobalt, nickel, and copper have been widely studied as alternatives to noble metal catalysts. High-entropy alloys, as single-phase solid solutions composed of five or more metals, form abundant active sites through multi-element mixing. These active sites can be precisely optimized through elemental configuration and composition adjustment. Their unique high-entropy effect, lattice distortion, and cocktail effect endow the materials with excellent catalytic activity, selectivity, and stability, showing potential in reinforced, wear-resistant, and functional composite materials, making them promising candidates for applications in multiple fields. However, how to efficiently composite high-entropy alloys with carbon-based materials to synergistically leverage the advantages of each component in catalysis and multifunctional reinforcement remains a current research challenge.

[0004] Existing methods for preparing carbon-based composite catalysts generally suffer from problems such as harsh reaction conditions, high costs, and low yields. Furthermore, it is difficult to simultaneously achieve the comprehensive performance of the composite material (e.g., catalytic performance, mechanical reinforcement effect, stability, and durability). This limits their in-depth application in high-end catalysis fields and makes it difficult to meet the urgent need for nano-additives with both high catalytic activity and excellent multifunctionality in advanced engineering materials fields such as ultra-high performance concrete. Therefore, it is necessary to develop a carbon-based composite material that can combine high catalytic performance with excellent structural / functional properties and is easily prepared on a large scale to overcome the shortcomings of existing technologies. Summary of the Invention

[0005] This application provides a high-catalytic-performance carbon nanocomposite material, its preparation method, and its application, in order to solve the problems of poor catalytic performance, low utilization rate of active sites, poor structural synergy of traditional carbon-based materials, difficulty in efficient composite of high-entropy alloys and carbon-based materials, high preparation cost and low yield of existing materials, and difficulty in achieving both high catalytic activity and excellent structural and functional properties, thus failing to meet the demand for high-performance, multifunctional core material composites in the fields of electrocatalysis and ultra-high performance concrete.

[0006] This application provides a high-catalytic-performance carbon nanocomposite material, comprising: a nitrogen-doped ordered mesoporous carbon substrate; cobalt nanoparticles generated in situ and loaded on the surface and pores of the ordered mesoporous carbon substrate; and high-entropy alloy nanoparticles loaded on the ordered mesoporous carbon substrate and the cobalt nanoparticles, wherein the cobalt nanoparticles serve as nucleation centers, and they diffuse and alloy with other added metal elements, such that the cobalt element in the high-entropy alloy nanoparticles is partially derived from the cobalt nanoparticles.

[0007] Optionally, the high-entropy alloy nanoparticles are composed of five metallic elements: iron, cobalt, nickel, copper, and chromium.

[0008] Optionally, the mesoporous structure of the nitrogen-doped ordered mesoporous carbon substrate is formed by template SBA-15.

[0009] Optionally, the nitrogen element in the nitrogen doping is derived from the polymerization and pyrolysis of dopamine.

[0010] Optionally, the ratio of the sum of the masses of the nitrogen-doped ordered mesoporous carbon substrate and the cobalt nanoparticles to the total mass of the high-entropy alloy nanoparticles is (0.8-3.5):1.

[0011] This application also proposes a method for preparing high-catalytic-performance carbon nanocomposite materials, comprising the following steps:

[0012] Step 1: After crushing and grinding the forage raw material, wash it with distilled water to obtain forage powder. Mix it with sodium hydroxide solution at a solid-liquid ratio of 1:8-12, heat it in an oil bath at 85-95℃ for 1-2 hours, centrifuge to obtain a supernatant rich in lignin, add acid to the supernatant to adjust the pH value to 2.5-3.5, stir slowly to precipitate lignin, obtain acid-precipitated lignin, dry and crush it, disperse it in deionized water, adjust the pH value to 9.0-11.0 with sodium hydroxide solution, add sodium sulfite, and carry out sulfonation reaction at 105-115℃ for 3-4 hours under closed conditions. Dry the reaction product to obtain sodium lignin sulfonate.

[0013] Step 2: Disperse the SBA-15 template in a tris(hydroxymethyl)aminomethane buffer solution with a pH of 8.0-9.0, then add dopamine, sodium lignosulfonate, and cobalt nitrate hexahydrate in sequence. After mixing evenly, let it stand at room temperature in the dark for 12-36 hours. Then add a methanol solution of 1,2-dimethylimidazole and react in a microwave reactor at 95-105℃ for 2-5 minutes to quickly complete coordination and assembly. After the reaction is completed, centrifuge the mixture, wash the obtained solid with methanol and dry it at 50-70℃ to obtain the solid precursor.

[0014] Step 3: The solid precursor is placed in an inert atmosphere and heated to 750-850℃ at a heating rate of 1-5℃ / min and calcined for 2-4 hours. After natural cooling, the calcined product is placed in an aqueous sodium hydroxide solution and heated at 75-85℃ for 2-3 hours to remove the template. Then, solid-liquid separation is performed. The obtained solid is washed and dried to obtain nitrogen-doped ordered mesoporous carbon loaded with cobalt nanoparticles.

[0015] Step 4: The nitrogen-doped ordered mesoporous carbon is uniformly dispersed in ethanol, and a chloride solution containing five metal elements (iron, cobalt, nickel, copper, and chromium) is added to it. The mixture is stirred at room temperature for 20-28 hours for impregnation. Then, the mixture is evaporated at 70-85°C to remove the solvent, resulting in a dry intermediate. The intermediate is then heated to 850-950°C at a heating rate of 5-15°C / min and calcined for 1-3 hours in a reducing atmosphere or a reducing / inert mixed atmosphere. During this high-temperature reduction and alloying process, the added metal elements diffuse and fuse with some in-situ cobalt nanoparticles to form high-entropy alloy nanoparticles on the carbon substrate. After cooling, a carbon nanocomposite material is obtained. The high-entropy alloy nanoparticles are characterized by X-ray diffraction as a single face-centered cubic solid solution phase.

[0016] Optionally, in step two, the mass ratios of the SBA-15 template to the dopamine, the sodium lignosulfonate, and the cobalt nitrate hexahydrate are 1:(1.2-1.8), 1:(2.5-3.5), and 1:(0.25-0.35), respectively, and the molar ratio of 1,2-dimethylimidazole to cobalt nitrate hexahydrate is (2-4):1.

[0017] Optionally, in step four, the concentration of the metal chloride in the chloride solution is 20-30 mg / mL, the molar ratio of the five metal elements (iron, cobalt, nickel, copper, and chromium) is (0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2), and the reducing / inert mixed atmosphere is a mixture of hydrogen and argon.

[0018] This application also proposes an application of a high-catalytic-performance carbon nanocomposite material in the field of electrocatalysis.

[0019] Optionally, it can be used in the preparation of ultra-high performance concrete as a functional additive.

[0020] Therefore, this application has at least the following beneficial effects:

[0021] (1) The carbon nanocomposite material provided in this application achieves multi-scale structural complementarity and functional synergy through a three-level composite system consisting of a nitrogen-doped ordered mesoporous carbon substrate, in-situ cobalt nanoparticles, and high-entropy alloy nanoparticles. The ordered mesoporous carbon framework has a high specific surface area and interconnected channels, which provides an efficient mass transfer pathway and abundant active site loading space for electrocatalytic reactions, and also lays the foundation for loading functional components (such as corrosion inhibitors) in UHPC nanocontainers. Nitrogen doping not only regulates the surface electronic state of the carbon substrate, enhances its conductivity, and optimizes the electronic interaction with the metal active center, which is crucial for improving electrocatalytic activity and charge transport efficiency, but also enhances the interfacial bonding with other components such as cement matrix. The in-situ generated and uniformly distributed cobalt nanoparticles, as an efficient electron transport bridge and nucleation center for subsequent alloying, optimize the charge migration within the composite material. The high-entropy alloy nanoparticles formed with it as the core significantly improve the overall catalytic activity, selectivity, and structural stability of the composite material through multi-element synergy and a stable solid solution structure. This tertiary structure enables the composite material to simultaneously meet the requirements of electrocatalysis for highly active and stable electrode materials, as well as UHPC's expectation for high-performance and multifunctional nano-additives.

[0022] (2) In this embodiment, SBA-15 mesoporous silica is used as a hard template. Its highly ordered and uniformly sized nanopores provide an ideal platform for achieving uniform nanoscale composite and spatial confinement of components. Sodium lignosulfonate, dopamine, and cobalt precursor are precisely assembled in the template pores and formed a zeolite-like imidazole ester framework precursor by microwave-assisted coordination. This process ensures the uniform mixing and positioning of carbon, nitrogen, and cobalt sources at the molecular scale. Finally, after calcination and etching, the ordered structure of the template is perfectly replicated in the carbon framework to form nitrogen-doped ordered mesoporous carbon and generate cobalt nanoparticles with controllable size in situ. This construction path not only provides a reliable method for obtaining composite supports with high regularity and high specific surface area, ensuring the efficient transport of reactants and products during electrocatalysis, but also provides key technical guarantees for uniformly and stably introducing nanofunctional phases into the UHPC matrix, avoiding aggregation, and thus exerting their enhancing and modifying effects.

[0023] (3) The embodiments of this application adopt a one-step programmed temperature rise calcination process, which simultaneously completes the carbonization of the precursor, nitrogen doping and in-situ reduction of cobalt nanoparticles in an inert atmosphere, significantly simplifying the process flow. During this process, the release of nitrogen-containing species realizes the chemical doping of nitrogen atoms into the carbon lattice, while the cobalt species are carbothermally reduced. The newly formed cobalt atoms form strong Co-Nx coordination bonds with the doped nitrogen atoms (especially pyridine nitrogen) in the carbon skeleton. This strong interaction is like a "chemical rivet", firmly anchoring the cobalt nanoparticles to the carbon skeleton. On the one hand, this effectively prevents the loss and aggregation of active components during electrochemical cycling, greatly improving the long-term stability of the electrode material; on the other hand, it also constructs a stable metal-carrier interface, ensuring the structural integrity of the nano-reinforcing phase in harsh service environments when the composite material is used as a UHPC additive, thereby ensuring its long-term performance.

[0024] (4) In this embodiment, a high-entropy alloy active phase with in-situ cobalt nanoparticles as the nucleation center was successfully constructed by introducing various metal salts onto cobalt-loaded mesoporous carbon and then reducing and alloying it at high temperature. The extremely high mixing entropy drives the mutual diffusion of various metal atoms to form a single face-centered cubic solid solution, and its significant lattice distortion modulates the electronic structure of the alloy. The unique multi-element synergistic effect and "cocktail effect" of the high-entropy alloy create rich and tunable catalytic active sites, which is crucial for achieving high sensitivity and high selectivity electrocatalysis. At the same time, the strong interaction between the alloy phase and the carbon substrate, as well as its inherent thermodynamic stability and environmental corrosion resistance, fundamentally solves the problem of easy deactivation and agglomeration of nanoparticles in complex application environments, so that the composite material can maintain excellent performance stability in repeated electrochemical tests or in alkaline and high-humidity concrete environments.

[0025] (5) The carbon nanocomposite material prepared in the embodiments of this application possesses a highly ordered mesoporous structure, excellent chemical stability, high specific surface area, good conductivity, and tunable surface activity. These comprehensive properties make it exhibit clear application value and potential in both electrocatalysis and ultra-high performance concrete. In the field of electrocatalysis, the electrode modified with this material exhibits high sensitivity, low detection limit, wide linear range, and excellent anti-interference and long-term stability for specific targets (such as chloramphenicol), making it suitable for the accurate and rapid detection of trace substances. In the field of UHPC, this material, as a functional additive, can play a multi-faceted synergistic reinforcing role: First, its mesoporous structure can be used to load and intelligently release functional components such as rust inhibitors and antibacterial agents, providing internal active protection for UHPC and improving durability. Second, the high-strength, stable carbon skeleton and uniformly distributed nanoparticles can serve as efficient nano-reinforcing phases, improving the mechanical properties and toughness of UHPC. Third, the conductive network constructed from nitrogen-doped carbon and high-entropy alloys effectively endows UHPC with overall conductivity, making it potential for applications such as snow melting and de-icing, electromagnetic shielding, or stress / damage self-sensing. Fourth, the catalytically active sites on the material surface can endow UHPC components with the environmental purification function of photocatalytic degradation of pollutants. This provides an innovative solution for developing a new generation of advanced materials that combine high-performance sensing capabilities with multifunctional engineering properties.

[0026] This addresses the problems of poor catalytic performance, low utilization of active sites, and poor structural synergy of traditional carbon-based materials; the difficulty in efficiently combining high-entropy alloys with carbon-based materials; the high cost and low yield of existing materials; and the inability to simultaneously meet the demand for high-performance, multifunctional core materials in the fields of electrocatalysis and ultra-high-performance concrete.

[0027] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0028] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 This is a flowchart illustrating a method for preparing a high-catalytic-performance carbon nanocomposite material according to an embodiment of this application;

[0030] Figure 2 The images are electron microscope images of the carbon nanocomposites prepared in Examples 1-3, where (A) and (D) are scanning electron microscope images of the composite material prepared in Example 1, (B) and (E) are scanning electron microscope images of the composite material prepared in Example 2, and (C) and (F) are scanning electron microscope images of the composite material prepared in Example 3.

[0031] Figure 3 The following is an elemental distribution map of the carbon nanocomposite material prepared in Example 1; wherein, (A) is a mapping map of all elements, (B) is a mapping map of C element, (C) is a mapping map of N element, (D) is a mapping map of O element, (E) is a mapping map of S element, (F) is a mapping map of Fe element, (G) is a mapping map of Co element, (H) is a mapping map of Ni element, (I) is a mapping map of Cu element, and (J) is a mapping map of Cr element;

[0032] Figure 4 X-ray diffraction pattern of carbon nanocomposite material provided according to embodiments of this application;

[0033] Figure 5 X-ray photoelectron spectroscopy (XPS) of the carbon nanocomposite material prepared in Example 1; wherein, (A) is the overall spectrum of the composite material, (B) is the fine spectrum (C1s) peak diagram of element C, (C) is the fine spectrum (N1s) peak diagram of element N, (D) is the fine spectrum (O1s) peak diagram of element O, (E) is the fine spectrum (Fe2p) peak diagram of element Fe, (F) is the fine spectrum (Co2p) peak diagram of element Co, (G) is the fine spectrum (Ni2p) peak diagram of element Ni, (H) is the fine spectrum (Cu2p) peak diagram of element Cu, and (I) is the fine spectrum (Cr2p) peak diagram of element Cr.

[0034] Figure 6 The figures show a comparison of the electrochemical performance of the modified electrodes prepared in Examples 1-3 and the comparative examples; (A) is a comparison of the cyclic voltammetry (CV) curves of different modified electrodes against chloramphenicol (300µM) at a scan rate of 50mV / s in phosphate buffer solution (PBS) at pH 7; (B) is the electrochemical impedance spectroscopy (EIS) of different modified electrodes in a potassium ferricyanide / potassium chloride mixed solution; and (C) is the CV curve of different modified electrodes in the above probe solution.

[0035] Figure 7 The differential pulse voltammetric response and calibration curve of the carbon nanocomposite modified electrode prepared in Example 1 to chloramphenicol; wherein, (A) is the DPV response curve of the modified electrode after adding different concentrations of chloramphenicol in PBS buffer solution at pH 7, and (B) is the linear relationship curve between chloramphenicol concentration and corresponding peak current value.

[0036] Figure 8 The graph shows the stability test results of the carbon nanocomposite material prepared in Example 1; where (A) is the anti-interference test graph, (B) is the long-term (14 days) stability test graph, (C) is the reproducibility test graph, (D) is the electrode regeneration test graph, and (E) is the cycle stability test graph. Detailed Implementation

[0037] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0038] In the embodiments of this application, unless otherwise specified, the raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0039] The present application will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present application in any way.

[0040] Example 1

[0041] This application provides a high-catalytic-performance carbon nanocomposite material, comprising: a nitrogen-doped ordered mesoporous carbon substrate; cobalt nanoparticles generated in situ and loaded on the surface and pores of the ordered mesoporous carbon substrate; and high-entropy alloy nanoparticles loaded on the ordered mesoporous carbon substrate and the cobalt nanoparticles, wherein the cobalt nanoparticles serve as nucleation centers, and diffuse and alloy with other added metal elements, so that the cobalt element in the high-entropy alloy nanoparticles is partly derived from the cobalt nanoparticles.

[0042] The high-entropy alloy nanoparticles are composed of five metallic elements: iron, cobalt, nickel, copper, and chromium.

[0043] It should be noted that the mesoporous structure of the nitrogen-doped ordered mesoporous carbon substrate is formed by the template SBA-15. The nitrogen element in the nitrogen doping is derived from the polymerization and pyrolysis of dopamine.

[0044] The ratio of the sum of the masses of nitrogen-doped ordered mesoporous carbon substrates and cobalt nanoparticles to the total mass of high-entropy alloy nanoparticles is (0.8-3.5):1.

[0045] This application also proposes a method for preparing high-catalytic-performance carbon nanocomposite materials, comprising the following steps:

[0046] Step 1: After crushing and grinding the forage raw material, wash it with distilled water to obtain forage powder. Mix it with sodium hydroxide solution at a solid-liquid ratio of 1:10, heat it in an oil bath at 90℃ for 1.5 hours, centrifuge to obtain a supernatant rich in lignin, add acid to the supernatant to adjust the pH value to 3.0, stir slowly to precipitate lignin, obtain acid-precipitated lignin, dry and crush it, disperse it in deionized water, adjust the pH value to 10.0 with sodium hydroxide solution, add sodium sulfite, and carry out sulfonation reaction at 110℃ for 3.5 hours under closed conditions. After drying the reaction product, obtain sodium lignin sulfonate.

[0047] It is understandable that the embodiments of this application utilize waste biomass raw materials such as forage grass to extract lignin and then perform sulfonation modification, thus achieving high-value utilization of agricultural and forestry waste. This process not only provides a green and low-cost carbon source for the composite material, but also, due to its good water solubility and surface activity, the generated sodium lignin sulfonate can effectively promote the dispersion of precursors in subsequent steps and synergistically work with the template agent to play a key role in the final formation of a highly ordered mesoporous carbon structure. This highly ordered mesoporous structure provides abundant mass transfer channels and active site loading space for electrocatalysis, and also lays the structural foundation for its use as a nanocontainer loading functional agent in UHPC.

[0048] Step 2: The SBA-15 template was dispersed in a tris(hydroxymethyl)aminomethane buffer solution with a pH of 8.5. Then, dopamine, sodium lignosulfonate and cobalt nitrate hexahydrate were added in sequence. After mixing evenly, the mixture was allowed to stand at room temperature in the dark for 24 hours. Then, a methanol solution of 1,2-dimethylimidazole was added. The mixture was reacted in a microwave reactor at 100°C for 2 minutes to quickly complete the coordination and assembly. After the reaction was completed, the mixture was centrifuged. The obtained solid was washed with methanol and dried at 60°C to obtain the solid precursor.

[0049] Understandably, in this embodiment, a zeolite-like imidazole ester (ZIF) precursor was constructed by introducing cobalt ions into the dopamine polymerization system and utilizing microwave-assisted rapid coordination with 1,2-dimethylimidazole. At the molecular scale, the carbon, nitrogen, and cobalt sources were confined within the nanopores of the SBA-15 template, achieving uniform mixing and spatial positioning of the components. This lays a solid foundation for the subsequent pyrolysis preparation of a composite material with a well-defined structure and uniform component distribution. This process ensures uniform doping of nitrogen species and high dispersion of cobalt nanoparticles, which is crucial for obtaining stable and efficient electrocatalytic active centers. It also ensures the uniform distribution of the reinforcing phase within the matrix when the final composite material is used as an additive in UHPC.

[0050] Step 3: The solid precursor was placed in an inert atmosphere and heated to 800℃ at a heating rate of 1℃ / min and calcined for 3 hours. After natural cooling, the calcined product was placed in an aqueous sodium hydroxide solution and heated at 80℃ for 2.5 hours to remove the template. Then, solid-liquid separation was performed. The obtained solid was washed and dried to obtain nitrogen-doped ordered mesoporous carbon loaded with cobalt nanoparticles.

[0051] Understandably, this embodiment of the application achieves pyrolysis forming of the carbon framework, in-situ doping of nitrogen atoms, and in-situ reduction and confinement of cobalt species in one step by calcining the solid precursor under an inert atmosphere. During this process, nitrogen-containing species generated from dopamine pyrolysis combine with the carbon network, achieving uniform nitrogen doping. Simultaneously, cobalt ions are carbothermally reduced to generate metallic cobalt nanoparticles, which form strong coordination bonds with the nitrogen atoms doped in the carbon framework. These chemical bonds act as anchor points, firmly fixing the cobalt nanoparticles to the inner surface of the ordered mesoporous carbon channels, effectively preventing their migration and aggregation. Subsequently, alkaline etching removes the template, perfectly replicating its highly ordered mesoporous structure. Ultimately, a nitrogen-doped ordered mesoporous carbon loaded with cobalt nanoparticles is obtained, exhibiting stable structure, excellent conductivity, and uniform distribution of active sites, providing an ideal support platform for subsequent loading of high-entropy alloys.

[0052] Step 4: Nitrogen-doped ordered mesoporous carbon is uniformly dispersed in ethanol. A chloride solution containing five metal elements (iron, cobalt, nickel, copper, and chromium) is added to the mixture. The mixture is stirred at room temperature for 24 hours for impregnation. Then, the solvent is evaporated at 80°C to obtain a dry intermediate. The intermediate is then heated to 900°C and calcined for 2 hours at a heating rate of 10°C / min under a reducing atmosphere or a reducing / inert mixed atmosphere. During this high-temperature reduction and alloying process, the added metal elements diffuse and fuse with some in-situ cobalt nanoparticles to form high-entropy alloy nanoparticles on the carbon substrate. After cooling, a carbon nanocomposite material is obtained. In this composite material, the ratio of the total mass of the nitrogen-doped ordered mesoporous carbon substrate and cobalt nanoparticles to the total mass of the high-entropy alloy nanoparticles is 1.7:1. The high-entropy alloy nanoparticles are characterized by X-ray diffraction as a single face-centered cubic solid solution phase.

[0053] It is understood that the embodiments of this application successfully constructed a high-entropy alloy active phase with in-situ cobalt nanoparticles as the nucleation center by introducing multiple metal salts onto a cobalt-loaded carbon substrate and then performing high-temperature reduction and alloying. The high-entropy effect and lattice distortion endow this alloy phase with excellent structural stability and tunable electronic structure. Combining it with a conductive carbon support not only effectively prevents the aggregation of nanoparticles but also, through the synergistic effect of multiple components, gives the material excellent overall performance, providing a key material basis for its reinforcing, conductive, and surface functionalizing functions in ultra-high performance concrete applications.

[0054] In step two, the mass ratios of SBA-15 template to dopamine, sodium lignosulfonate, and cobalt nitrate hexahydrate are 1:1.5, 1:3.0, and 1:0.30, respectively, and the molar ratio of 1,2-dimethylimidazole to cobalt nitrate hexahydrate is 2:1.

[0055] It should be noted that the concentration of metal chloride in the chloride solution is 25 mg / mL, the molar ratio of the five metal elements (iron, cobalt, nickel, copper, and chromium) is 1.0:1.0:1.0:1.0:1.0, and the reducing / inert mixed atmosphere is a mixture of hydrogen and argon.

[0056] This application also proposes the application of a high-catalytic-performance carbon nanocomposite material in the fields of electrocatalysis and preparation of ultra-high-performance concrete.

[0057] Example 2

[0058] This application provides a high-catalytic-performance carbon nanocomposite material, comprising: a nitrogen-doped ordered mesoporous carbon substrate; cobalt nanoparticles generated in situ and loaded on the surface and pores of the ordered mesoporous carbon substrate; and high-entropy alloy nanoparticles loaded on the ordered mesoporous carbon substrate and the cobalt nanoparticles, wherein the cobalt nanoparticles serve as nucleation centers, and diffuse and alloy with other added metal elements, so that the cobalt element in the high-entropy alloy nanoparticles is partly derived from the cobalt nanoparticles.

[0059] The high-entropy alloy nanoparticles are composed of five metallic elements: iron, cobalt, nickel, copper, and chromium.

[0060] It should be noted that the mesoporous structure of the nitrogen-doped ordered mesoporous carbon substrate is formed by the template SBA-15.

[0061] The nitrogen element in the nitrogen doping comes from the polymerization and pyrolysis of dopamine.

[0062] The ratio of the sum of the masses of nitrogen-doped ordered mesoporous carbon substrates and cobalt nanoparticles to the total mass of high-entropy alloy nanoparticles is (0.8-3.5):1.

[0063] This application also proposes a method for preparing high-catalytic-performance carbon nanocomposite materials, comprising the following steps:

[0064] Step 1: After crushing and grinding the forage raw material, wash it with distilled water to obtain forage powder. Mix it with sodium hydroxide solution at a solid-liquid ratio of 1:10, heat it in an oil bath at 90℃ for 1.5 hours, centrifuge to obtain a supernatant rich in lignin, add acid to the supernatant to adjust the pH value to 3.0, stir slowly to precipitate lignin, obtain acid-precipitated lignin, dry and crush it, disperse it in deionized water, adjust the pH value to 10.0 with sodium hydroxide solution, add sodium sulfite, and carry out sulfonation reaction at 110℃ for 3.5 hours under closed conditions. After drying the reaction product, obtain sodium lignin sulfonate.

[0065] It is understandable that the embodiments of this application utilize waste biomass raw materials such as forage grass to extract lignin and then perform sulfonation modification, thus achieving high-value utilization of agricultural and forestry waste. This process not only provides a green and low-cost carbon source for the composite material, but also, due to its good water solubility and surface activity, the generated sodium lignin sulfonate can effectively promote the dispersion of precursors in subsequent steps and synergistically work with the template agent to play a key role in the final formation of a highly ordered mesoporous carbon structure. This highly ordered mesoporous structure provides abundant mass transfer channels and active site loading space for electrocatalysis, and also lays the structural foundation for its use as a nanocontainer loading functional agent in UHPC.

[0066] Step 2: The SBA-15 template was dispersed in a tris(hydroxymethyl)aminomethane buffer solution with a pH of 8.5. Then, dopamine, sodium lignosulfonate and cobalt nitrate hexahydrate were added in sequence. After mixing evenly, the mixture was allowed to stand at room temperature in the dark for 24 hours. Then, a methanol solution of 1,2-dimethylimidazole was added. The mixture was reacted in a microwave reactor at 100°C for 2 minutes to quickly complete the coordination and assembly. After the reaction was completed, the mixture was centrifuged. The obtained solid was washed with methanol and dried at 60°C to obtain the solid precursor.

[0067] Understandably, in this embodiment, a zeolite-like imidazole ester (ZIF) precursor was constructed by introducing cobalt ions into the dopamine polymerization system and utilizing microwave-assisted rapid coordination with 1,2-dimethylimidazole. At the molecular scale, the carbon, nitrogen, and cobalt sources were confined within the nanopores of the SBA-15 template, achieving uniform mixing and spatial positioning of the components. This lays a solid foundation for the subsequent pyrolysis preparation of a composite material with a well-defined structure and uniform component distribution. This process ensures uniform doping of nitrogen species and high dispersion of cobalt nanoparticles, which is crucial for obtaining stable and efficient electrocatalytic active centers. It also ensures the uniform distribution of the reinforcing phase within the matrix when the final composite material is used as an additive in UHPC.

[0068] Step 3: The solid precursor was placed in an inert atmosphere and heated to 800℃ at a heating rate of 1℃ / min and calcined for 3 hours. After natural cooling, the calcined product was placed in an aqueous sodium hydroxide solution and heated at 80℃ for 2.5 hours to remove the template. Then, solid-liquid separation was performed. The obtained solid was washed and dried to obtain nitrogen-doped ordered mesoporous carbon loaded with cobalt nanoparticles.

[0069] Understandably, this embodiment of the application achieves pyrolysis forming of the carbon framework, in-situ doping of nitrogen atoms, and in-situ reduction and confinement of cobalt species in one step by calcining the solid precursor under an inert atmosphere. During this process, nitrogen-containing species generated from dopamine pyrolysis combine with the carbon network, achieving uniform nitrogen doping. Simultaneously, cobalt ions are carbothermally reduced to generate metallic cobalt nanoparticles, which form strong coordination bonds with the nitrogen atoms doped in the carbon framework. These chemical bonds act as anchor points, firmly fixing the cobalt nanoparticles to the inner surface of the ordered mesoporous carbon channels, effectively preventing their migration and aggregation. Subsequently, alkaline etching removes the template, perfectly replicating its highly ordered mesoporous structure. Ultimately, a nitrogen-doped ordered mesoporous carbon loaded with cobalt nanoparticles is obtained, exhibiting stable structure, excellent conductivity, and uniform distribution of active sites, providing an ideal support platform for subsequent loading of high-entropy alloys.

[0070] Step 4: Nitrogen-doped ordered mesoporous carbon was uniformly dispersed in ethanol. A chloride solution containing five metal elements—iron, cobalt, nickel, copper, and chromium—was added. The amount of metal salt solution added was adjusted, and the mixture was stirred at room temperature for 24 hours for impregnation. The solvent was then evaporated at 80°C to obtain a dry intermediate. This intermediate was then calcined at 900°C for 2 hours under a reducing atmosphere or a reducing / inert mixed atmosphere at a heating rate of 10°C / min. During this high-temperature reduction and alloying process, the added metal elements diffused and fused with some of the in-situ cobalt nanoparticles, forming high-entropy alloy nanoparticles on the carbon substrate. After cooling, a carbon nanocomposite material was obtained. In this composite material, the ratio of the sum of the masses of the nitrogen-doped ordered mesoporous carbon substrate and cobalt nanoparticles to the total mass of the high-entropy alloy nanoparticles was 3.4:1 (i.e., 1.7:0.5). The high-entropy alloy nanoparticles were characterized by X-ray diffraction as a single face-centered cubic solid solution phase.

[0071] It is understood that the embodiments of this application successfully constructed a high-entropy alloy active phase with in-situ cobalt nanoparticles as the nucleation center by introducing multiple metal salts onto a cobalt-loaded carbon substrate and then performing high-temperature reduction and alloying. The high-entropy effect and lattice distortion endow this alloy phase with excellent structural stability and tunable electronic structure. Combining it with a conductive carbon support not only effectively prevents the aggregation of nanoparticles but also, through the synergistic effect of multiple components, gives the material excellent overall performance, providing a key material basis for its reinforcing, conductive, and surface functionalizing functions in ultra-high performance concrete applications.

[0072] In step two, the mass ratios of SBA-15 template to dopamine, sodium lignosulfonate, and cobalt nitrate hexahydrate are 1:1.5, 1:3.0, and 1:0.30, respectively, and the molar ratio of 1,2-dimethylimidazole to cobalt nitrate hexahydrate is 2:1.

[0073] It should be noted that in step four, the concentration of metal chloride in the chloride solution is 25 mg / mL, the molar ratio of the five metal elements (iron, cobalt, nickel, copper, and chromium) is 1.0:1.0:1.0:1.0:1.0, and the reducing / inert mixed atmosphere is a mixture of hydrogen and argon.

[0074] This application also proposes the application of a high-catalytic-performance carbon nanocomposite material in the fields of electrocatalysis and preparation of ultra-high-performance concrete.

[0075] Example 3

[0076] This application provides a high-catalytic-performance carbon nanocomposite material, comprising: a nitrogen-doped ordered mesoporous carbon substrate; cobalt nanoparticles generated in situ and loaded on the surface and pores of the ordered mesoporous carbon substrate; and high-entropy alloy nanoparticles loaded on the ordered mesoporous carbon substrate and the cobalt nanoparticles, wherein the cobalt nanoparticles serve as nucleation centers, and diffuse and alloy with other added metal elements, so that the cobalt element in the high-entropy alloy nanoparticles is partly derived from the cobalt nanoparticles.

[0077] The high-entropy alloy nanoparticles are composed of five metallic elements: iron, cobalt, nickel, copper, and chromium.

[0078] It should be noted that the mesoporous structure of the nitrogen-doped ordered mesoporous carbon substrate is formed by the template SBA-15.

[0079] The nitrogen element in the nitrogen doping comes from the polymerization and pyrolysis of dopamine.

[0080] The ratio of the sum of the masses of nitrogen-doped ordered mesoporous carbon substrates and cobalt nanoparticles to the total mass of high-entropy alloy nanoparticles is (0.8-3.5):1.

[0081] This application also proposes a method for preparing high-catalytic-performance carbon nanocomposite materials, comprising the following steps:

[0082] Step 1: After crushing and grinding the forage raw material, wash it with distilled water to obtain forage powder. Mix it with sodium hydroxide solution at a solid-liquid ratio of 1:10, heat it in an oil bath at 90℃ for 1.5 hours, centrifuge to obtain a supernatant rich in lignin, add acid to the supernatant to adjust the pH value to 3.0, stir slowly to precipitate lignin, obtain acid-precipitated lignin, dry and crush it, disperse it in deionized water, adjust the pH value to 10.0 with sodium hydroxide solution, add sodium sulfite, and carry out sulfonation reaction at 110℃ for 3.5 hours under closed conditions. After drying the reaction product, obtain sodium lignin sulfonate.

[0083] It is understandable that the embodiments of this application utilize waste biomass raw materials such as forage grass to extract lignin and then perform sulfonation modification, thus achieving high-value utilization of agricultural and forestry waste. This process not only provides a green and low-cost carbon source for the composite material, but also, due to its good water solubility and surface activity, the generated sodium lignin sulfonate can effectively promote the dispersion of precursors in subsequent steps and synergistically work with the template agent to play a key role in the final formation of a highly ordered mesoporous carbon structure. This highly ordered mesoporous structure provides abundant mass transfer channels and active site loading space for electrocatalysis, and also lays the structural foundation for its use as a nanocontainer loading functional agent in UHPC.

[0084] Step 2: The SBA-15 template was dispersed in a tris(hydroxymethyl)aminomethane buffer solution with a pH of 8.5. Then, dopamine, sodium lignosulfonate and cobalt nitrate hexahydrate were added in sequence. After mixing evenly, the mixture was allowed to stand at room temperature in the dark for 24 hours. Then, a methanol solution of 1,2-dimethylimidazole was added. The mixture was reacted in a microwave reactor at 100°C for 2 minutes to quickly complete the coordination and assembly. After the reaction was completed, the mixture was centrifuged. The obtained solid was washed with methanol and dried at 60°C to obtain the solid precursor.

[0085] Understandably, in this embodiment, a zeolite-like imidazole ester (ZIF) precursor was constructed by introducing cobalt ions into the dopamine polymerization system and utilizing microwave-assisted rapid coordination with 1,2-dimethylimidazole. At the molecular scale, the carbon, nitrogen, and cobalt sources were confined within the nanopores of the SBA-15 template, achieving uniform mixing and spatial positioning of the components. This lays a solid foundation for the subsequent pyrolysis preparation of a composite material with a well-defined structure and uniform component distribution. This process ensures uniform doping of nitrogen species and high dispersion of cobalt nanoparticles, which is crucial for obtaining stable and efficient electrocatalytic active centers. It also ensures the uniform distribution of the reinforcing phase within the matrix when the final composite material is used as an additive in UHPC.

[0086] Step 3: The solid precursor was placed in an inert atmosphere and heated to 800℃ at a heating rate of 1℃ / min and calcined for 3 hours. After natural cooling, the calcined product was placed in an aqueous sodium hydroxide solution and heated at 80℃ for 2.5 hours to remove the template. Then, solid-liquid separation was performed. The obtained solid was washed and dried to obtain nitrogen-doped ordered mesoporous carbon loaded with cobalt nanoparticles.

[0087] Understandably, this embodiment of the application achieves pyrolysis forming of the carbon framework, in-situ doping of nitrogen atoms, and in-situ reduction and confinement of cobalt species in one step by calcining the solid precursor under an inert atmosphere. During this process, nitrogen-containing species generated from dopamine pyrolysis combine with the carbon network, achieving uniform nitrogen doping. Simultaneously, cobalt ions are carbothermally reduced to generate metallic cobalt nanoparticles, which form strong coordination bonds with the nitrogen atoms doped in the carbon framework. These chemical bonds act as anchor points, firmly fixing the cobalt nanoparticles to the inner surface of the ordered mesoporous carbon channels, effectively preventing their migration and aggregation. Subsequently, alkaline etching removes the template, perfectly replicating its highly ordered mesoporous structure. Ultimately, a nitrogen-doped ordered mesoporous carbon loaded with cobalt nanoparticles is obtained, exhibiting stable structure, excellent conductivity, and uniform distribution of active sites, providing an ideal support platform for subsequent loading of high-entropy alloys.

[0088] Step 4: Nitrogen-doped ordered mesoporous carbon was uniformly dispersed in ethanol. A chloride solution containing five metal elements—iron, cobalt, nickel, copper, and chromium—was added. The amount of metal salt solution added was adjusted, and the mixture was stirred at room temperature for 24 hours for impregnation. The solvent was then evaporated at 80°C to obtain a dry intermediate. This intermediate was then calcined at 900°C for 2 hours under a reducing atmosphere or a reducing / inert mixed atmosphere at a heating rate of 10°C / min. During this high-temperature reduction and alloying process, the added metal elements diffused and fused with some of the in-situ cobalt nanoparticles, forming high-entropy alloy nanoparticles on the carbon substrate. After cooling, a carbon nanocomposite material was obtained. In this composite material, the ratio of the total mass of the nitrogen-doped ordered mesoporous carbon substrate and cobalt nanoparticles to the total mass of the high-entropy alloy nanoparticles was approximately 0.85:1 (i.e., 1.7:2). The high-entropy alloy nanoparticles were characterized by X-ray diffraction as a single face-centered cubic solid solution phase.

[0089] It is understood that the embodiments of this application successfully constructed a high-entropy alloy active phase with in-situ cobalt nanoparticles as the nucleation center by introducing multiple metal salts onto a cobalt-loaded carbon substrate and then performing high-temperature reduction and alloying. The high-entropy effect and lattice distortion endow this alloy phase with excellent structural stability and tunable electronic structure. Combining it with a conductive carbon support not only effectively prevents the aggregation of nanoparticles but also, through the synergistic effect of multiple components, gives the material excellent overall performance, providing a key material basis for its reinforcing, conductive, and surface functionalizing functions in ultra-high performance concrete applications.

[0090] In step two, the mass ratios of SBA-15 template to dopamine, sodium lignosulfonate, and cobalt nitrate hexahydrate are 1:1.5, 1:3.0, and 1:0.30, respectively, and the molar ratio of 1,2-dimethylimidazole to cobalt nitrate hexahydrate is 2:1.

[0091] It should be noted that in step four, the concentration of metal chloride in the chloride solution is 25 mg / mL, the molar ratio of the five metal elements (iron, cobalt, nickel, copper, and chromium) is 1.0:1.0:1.0:1.0:1.0, and the reducing / inert mixed atmosphere is a mixture of hydrogen and argon.

[0092] This application also proposes the application of a high-catalytic-performance carbon nanocomposite material in the fields of electrocatalysis and preparation of ultra-high-performance concrete.

[0093] Comparative Example 1

[0094] This application provides a carbon nanocomposite material in comparison, comprising: an ordered mesoporous carbon substrate; cobalt nanoparticles generated in situ and loaded on the surface and pores of the ordered mesoporous carbon substrate; and high-entropy alloy nanoparticles loaded on the ordered mesoporous carbon substrate and the cobalt nanoparticles, wherein the cobalt nanoparticles serve as nucleation centers and diffuse and alloy with other added metal elements, such that the cobalt element in the high-entropy alloy nanoparticles is partly derived from the cobalt nanoparticles.

[0095] The high-entropy alloy nanoparticles are composed of five metallic elements: iron, cobalt, nickel, copper, and chromium.

[0096] It should be noted that the mesoporous structure of the ordered mesoporous carbon substrate is formed by the template SBA-15.

[0097] This comparative example also proposes a method for preparing carbon nanocomposites, including the following steps:

[0098] Step 1: After crushing and grinding the forage raw material, wash it with distilled water to obtain forage powder. Mix it with sodium hydroxide solution at a solid-liquid ratio of 1:10, heat it in an oil bath at 90℃ for 1.5 hours, centrifuge to obtain a supernatant rich in lignin, add acid to the supernatant to adjust the pH value to 3.0, stir slowly to precipitate lignin, obtain acid-precipitated lignin, dry and crush it, disperse it in deionized water, adjust the pH value to 10.0 with sodium hydroxide solution, add sodium sulfite, and carry out sulfonation reaction at 110℃ for 3.5 hours under closed conditions. After drying the reaction product, obtain sodium lignin sulfonate.

[0099] Step 2: The SBA-15 template was dispersed in a tris(hydroxymethyl)aminomethane buffer solution with a pH of 8.5, followed by the addition of sodium lignosulfonate and cobalt nitrate hexahydrate. After mixing thoroughly, the mixture was allowed to stand at room temperature in the dark for 24 hours. Then, a methanol solution of 1,2-dimethylimidazole was added, and the mixture was reacted in a microwave reactor at 100°C for 2 minutes to complete coordination and assembly. After the reaction was completed, the mixture was centrifuged, and the resulting solid was washed with methanol and dried at 60°C to obtain the solid precursor.

[0100] Step 3: The solid precursor was placed in an inert atmosphere and heated to 800℃ at a heating rate of 1℃ / min and calcined for 3 hours. After natural cooling, the calcined product was placed in an aqueous sodium hydroxide solution and heated at 80℃ for 2.5 hours to remove the template. Then, solid-liquid separation was performed. The obtained solid was washed and dried to obtain ordered mesoporous carbon loaded with cobalt nanoparticles.

[0101] Step 4: Disperse ordered mesoporous carbon uniformly in ethanol, add a chloride solution containing five metal elements: iron, cobalt, nickel, copper, and chromium, and impregnate by stirring at room temperature for 24 hours. Then, evaporate the mixture at 80°C to remove the solvent and obtain a dry intermediate. Then, calcine the intermediate to 900°C at a heating rate of 10°C / min for 2 hours under a reducing atmosphere or a reducing / inert mixed atmosphere. After cooling, carbon nanocomposite material is obtained.

[0102] In step two, the mass ratios of SBA-15 template to sodium lignosulfonate and cobalt nitrate hexahydrate are 1:3.0 and 1:0.30, respectively, and the molar ratio of 1,2-dimethylimidazole to cobalt nitrate hexahydrate is 2:1.

[0103] It should be noted that the concentration of metal chloride in the chloride solution is 25 mg / mL, the molar ratio of the five metal elements (iron, cobalt, nickel, copper, and chromium) is 1.0:1.0:1.0:1.0:1.0, and the reducing / inert mixed atmosphere is a mixture of hydrogen and argon.

[0104] This application also proposes the application of a high-catalytic-performance carbon nanocomposite material in the fields of electrocatalysis and preparation of ultra-high-performance concrete.

[0105] Comparative Example 2

[0106] This application provides a carbon nanocomposite material, a nitrogen-doped ordered mesoporous carbon substrate, and high-entropy alloy nanoparticles loaded on the nitrogen-doped ordered mesoporous carbon substrate.

[0107] The high-entropy alloy nanoparticles are composed of five metallic elements: iron, cobalt, nickel, copper, and chromium.

[0108] It should be noted that the mesoporous structure of the nitrogen-doped ordered mesoporous carbon substrate is formed by the template SBA-15. The nitrogen element in the nitrogen doping is derived from the polymerization and pyrolysis of dopamine.

[0109] This comparative example also proposes a method for preparing carbon nanocomposites, including the following steps:

[0110] Step 1: After crushing and grinding the forage raw material, wash it with distilled water to obtain forage powder. Mix it with sodium hydroxide solution at a solid-liquid ratio of 1:10, heat it in an oil bath at 90℃ for 1.5 hours, centrifuge to obtain a supernatant rich in lignin, add acid to the supernatant to adjust the pH value to 3.0, stir slowly to precipitate lignin, obtain acid-precipitated lignin, dry and crush it, disperse it in deionized water, adjust the pH value to 10.0 with sodium hydroxide solution, add sodium sulfite, and carry out sulfonation reaction at 110℃ for 3.5 hours under closed conditions. After drying the reaction product, obtain sodium lignin sulfonate.

[0111] Step 2: Disperse the SBA-15 template in a tris(hydroxymethyl)aminomethane buffer solution with a pH of 8.5, then add dopamine and sodium lignosulfonate in sequence, mix well, and let stand at room temperature in the dark for 24 hours. Then centrifuge the mixture, wash the obtained solid with methanol and dry it at 60°C to obtain the solid precursor.

[0112] Step 3: The solid precursor was placed in an inert atmosphere and heated to 800℃ at a heating rate of 1℃ / min and calcined for 3 hours. After natural cooling, the calcined product was placed in an aqueous sodium hydroxide solution and heated at 80℃ for 2.5 hours to remove the template. Then, solid-liquid separation was performed. The obtained solid was washed and dried to obtain nitrogen-doped ordered mesoporous carbon.

[0113] Step 4: Nitrogen-doped ordered mesoporous carbon is uniformly dispersed in ethanol, and a chloride solution containing five metal elements (iron, cobalt, nickel, copper and chromium) is added to it (the solution contains cobalt salt). The mixture is stirred at room temperature for 24 hours for impregnation. Then, the solvent is evaporated at 80°C to obtain a dry intermediate. The intermediate is then heated to 900°C and calcined for 2 hours at a heating rate of 10°C / min under a reducing atmosphere or a reducing / inert mixed atmosphere. After cooling, carbon nanocomposite material is obtained.

[0114] In step two, the mass ratios of SBA-15 template to dopamine and sodium lignosulfonate are 1:1.5 and 1:3.0, respectively.

[0115] It should be noted that the concentration of metal chloride in the chloride solution is 25 mg / mL, the molar ratio of the five metal elements (iron, cobalt, nickel, copper, and chromium) is 1.0:1.0:1.0:1.0:1.0, and the reducing / inert mixed atmosphere is a mixture of hydrogen and argon.

[0116] This application also proposes the application of a high-catalytic-performance carbon nanocomposite material in the fields of electrocatalysis and preparation of ultra-high-performance concrete.

[0117] Comparative Example 3

[0118] This comparative example provides a conventional carbon nanocomposite material, a cobalt / ordered mesoporous carbon catalyst prepared by a conventional impregnation-calcination method. The cobalt nanoparticles have a size of approximately 10-20 nm and a mass loading of 10 wt%.

[0119] Performance testing and characterization

[0120] To verify the structure, properties, and technical effects of the carbon nanocomposite material of the present invention, Examples 1-3 were strictly conducted in accordance with... Figure 1 The samples were prepared using the method shown. For comparison, comparative examples 1-3 were prepared by adjusting specific steps in the process. All samples were systematically tested and characterized, and the results are as follows.

[0121] Characterization of the core microstructure of materials

[0122] The core microstructure of the example and comparative samples was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) to reveal their nanoscale and atomic scale structures. The performance test data are shown in Table 1.

[0123] Table 1 Characterization of the core microstructure of carbon nanocomposites

[0124]

[0125] The data in Table 1 reveal the essential reasons for the differences in material properties at the nanoscale and atomic scale. Figure 2 The images show scanning electron microscope (SEM) images of the carbon nanocomposites prepared in Examples 1-3 at a scale of 500 nm. (A) and (D) are SEM images of the composite material prepared in Example 1, (B) and (E) are SEM images of the composite material prepared in Example 2, and (C) and (F) are SEM images of the composite material prepared in Example 3. As can be seen from the images, the carbon nanocomposites prepared in Examples 1-3 all exhibit a highly ordered two-dimensional hexagonal mesoporous morphology, indicating that the ordered pore structure of the SBA-15 template was perfectly replicated in the carbon skeleton. Figure 3The elemental distribution map of the carbon nanocomposite material prepared in Example 1 is shown at a scale of 500 nm. In the map, (A) is the mapping map of all elements, (B) is the mapping map of C, (C) is the mapping map of N, (D) is the mapping map of O, (E) is the mapping map of S, (F) is the mapping map of Fe, (G) is the mapping map of Co, (H) is the mapping map of Ni, (I) is the mapping map of Cu, and (J) is the mapping map of Cr. The elemental distribution map clearly shows that the signals of the five metal elements Fe, Co, Ni, Cu, and Cr are highly overlapping and uniformly distributed in the nanoparticle region. This provides the most direct evidence for the interdiffusion of multiple metal atoms and the formation of a homogeneous solid solution, confirming the successful loading of high-entropy alloy nanoparticles. Crystal structure analysis is as follows: Figure 4 As shown, the X-ray diffraction patterns of Examples 1-3 exhibit sharp diffraction peaks near 2θ = 44.2°, 51.5°, and 75.9°, with no other impurity phases. Comparison with standard cards revealed that these characteristic peaks perfectly matched the (111), (200), and (220) crystal planes of the face-centered cubic (FCC) structure, confirming the successful synthesis of the single-phase high-entropy alloy solid solution. Simultaneously, the diffraction peaks observed near 2θ = 36.2° and 42.2° can be attributed to CoN, indicating a strong interaction between the cobalt species and the nitrogen-doped carbon substrate. Further detailed analysis of the surface chemical state and electronic structure was performed using X-ray photoelectron spectroscopy. Figure 5 X-ray photoelectron spectroscopy (XPS) of the carbon nanocomposite material prepared in Example 1 is shown below. In the figure, (A) is the overall spectrum of the composite material, (B) is the fine spectrum (C1s) peak diagram of element C, (C) is the fine spectrum (N1s) peak diagram of element N, (D) is the fine spectrum (O1s) peak diagram of element O, (E) is the fine spectrum (Fe2p) peak diagram of element Fe, (F) is the fine spectrum (Co2p) peak diagram of element Co, (G) is the fine spectrum (Ni2p) peak diagram of element Ni, (H) is the fine spectrum (Cu2p) peak diagram of element Cu, and (I) is the fine spectrum (Cr2p) peak diagram of element Cr. The overall spectrum confirmed the presence of all target elements; the high-resolution C1s spectrum could be fitted with three main peak positions: C=C, CN, and C=O / CO, with the presence of the CN peak confirming successful nitrogen doping; the N1s spectrum further resolved active forms such as pyridine nitrogen, pyrrole nitrogen, and nitrogen oxides, with a total nitrogen content of approximately 5.2 at%; most importantly, the high-resolution Co2p spectrum observed a binding energy peak belonging to zero-valent cobalt and obvious satellite peaks, while the spectrum showed a binding energy shift related to pyridine nitrogen coordination, which directly confirmed the formation of strong Co-Nx coordination bonds; in addition, the Fe2p, Ni2p, Cu2p, and Cr2p spectra together revealed the complex electronic structure of each metal element coexisting in zero-valent and oxidation states in the high-entropy alloy phase.

[0126] In contrast, Comparative Example 1, lacking a nitrogen source during synthesis, showed no nitrogen signal detected by XPS, while XRD revealed an increase in the grain size of the high-entropy alloy. Comparative Example 2, lacking pre-formed cobalt nanoparticles as nucleation centers, resulted in coarsened alloy particles and a weak Co-Nx coordination signal. Comparative Example 3 only observed cobalt and its oxide phases. These systematic characterization results demonstrate that the multi-level composite structure synergistically constructed by the nitrogen-doped ordered mesoporous carbon substrate, in-situ cobalt nanoparticle nucleation centers, and the high-entropy alloy active phase is the microscopic basis for the material's superior performance.

[0127] Electrocatalytic performance test

[0128] The carbon nanocomposites prepared in Examples 1-3 and Comparative Examples 1-3 were modified onto glassy carbon electrodes. In a phosphate buffer solution with a pH of 7.0, different concentrations of chloramphenicol were added as the target analyte to evaluate their performance as electrocatalytic materials for the detection of chloramphenicol. The performance test data are shown in Table 2 below.

[0129] Table 2 Electrocatalytic detection performance of carbon nanocomposites for chloramphenicol

[0130]

[0131] As shown in Table 2, the materials in the examples all exhibited excellent electrocatalytic detection performance for chloramphenicol. Figure 6 The figures show a comparison of the electrochemical performance of the modified electrodes prepared in Examples 1-3 and the comparative examples. (A) is a comparison of the cyclic voltammetry (CV) curves of different modified electrodes against chloramphenicol (300 µM) at a scan rate of 50 mV / s in phosphate buffered saline (PBS) at pH 7; (B) is the electrochemical impedance spectroscopy (EIS) spectrum of different modified electrodes in a potassium ferricyanide / potassium chloride mixed solution; and (C) is the CV curve of different modified electrodes in the above probe solution. The electrode labeled GCE represents a blank glassy carbon electrode as a substrate reference, and the electrode labeled N-BDOC represents an electrode modified only by nitrogen-doped ordered mesoporous carbon as a support reference. The terms represent the carbon nanocomposite modified electrodes prepared in Examples 1, 2, and 3, respectively. Based on the above correspondence analysis, it can be seen that... Figure 6 (A) As can be seen, the composite material prepared in Example 1 exhibits the highest electrochemical response current (28.38 µA) to chloramphenicol; Figure 6 (B) It can be seen that it has the smallest charge transfer impedance (11.34Ω); from Figure 6(C) As can be seen, it has the largest electrochemical active area (0.14 cm²). These data indicate that the material of Example 1 has the best electron transfer capability and catalytic active sites, laying the foundation for high-sensitivity detection. Furthermore, quantitative analysis was performed on the material of Example 1 with the best performance. Figure 7 The differential pulse voltammetry (DPV) response and calibration curves of the carbon nanocomposite modified electrode prepared in Example 1 to chloramphenicol are shown. (A) is the DPV response curve of the modified electrode after adding different concentrations of chloramphenicol (0.05 to 600 µM) to a PBS buffer solution at pH 7; (B) is the linear relationship (calibration) curve between chloramphenicol concentration and the corresponding peak current value. Figure 7 As shown in (A), the peak current value increases regularly with the increase of chloramphenicol concentration. Figure 7 The calibration curve shown in (B) exhibits two segments of good linearity, with a sensitivity as high as 0.3809 µA / µM in the low concentration range (0.05-200 µM). Furthermore, Figure 8 The figures show the stability test results of the carbon nanocomposite material prepared in Example 1; where (A) is the anti-interference test figure, (B) is the long-term (14 days) stability test figure, (C) is the reproducibility test figure, (D) is the electrode regeneration test figure, and (E) is the cycle stability test figure. Specifically, the anti-interference test ( Figure 8 (A) indicates that various common ions and biomolecules have minimal interference with the chloramphenicol detection signal; long-term stability tests ( Figure 8 (B) shows that the current response retention rate reached 96.3% after 14 days of storage; reproducibility test ( Figure 8 (C) The test was performed on four parallel prepared modified electrodes, and the calculated RSD was 1.26%, indicating that the composite material prepared in Example 1 has excellent reproducibility; Electrode regenerability test ( Figure 8 In (D), after detecting chloramphenicol using a modified electrode and eluting with deionized water, the RSD of the current response was 1.86% after 4 cycles, indicating that the composite material prepared in Example 1 has good electrochemical regeneration performance; cyclic stability test ( Figure 8 (E) The composite material prepared in Example 1 was continuously run for 20 cycles at a scan rate of 50 mV / s using the cyclic voltammetry method. Compared with the initial current, the current response decreased by only 3.3% after 20 cycles, which proves that the composite material prepared in Example 1 has good cyclic stability and reliable durability.

[0132] In contrast, all comparative materials exhibited a systematic decline in electrocatalytic activity, electron transport efficiency, and stability due to the absence of key components in the tertiary composite structure. This objectively confirms the indispensability of the complete system comprised of the conductivity and anchoring effect provided by the nitrogen-doped carbon substrate, the electron bridging and nucleation function of cobalt nanoparticles, and the multi-element synergistic catalytic effect of the high-entropy alloy for achieving exceptional electrocatalytic performance.

[0133] The material was used as a functional additive and introduced into the reference UHPC at a dosage of 0.5% of the cementitious material mass to prepare composite reinforced UHPC samples. The mechanical properties, durability and emerging functionalities of the samples were tested, and the results are shown in Table 3.

[0134] Table 3. Effect of carbon nanocomposites on UHPC performance

[0135]

[0136] As shown in Table 3, the UHPC incorporated into the example materials exhibits significantly improved overall performance. In terms of mechanical properties, the compressive and flexural strengths of all example groups are substantially increased, thanks to the strong interfacial bonding between the nitrogen-doped carbon skeleton and the cement matrix, as well as the filling, reinforcement, and crack bridging effects generated by the uniformly dispersed nanoparticles (cobalt particles and high-entropy alloys). Regarding durability, the chloride ion migration coefficient of the UHPC in the example groups is significantly reduced, indicating a denser microstructure and enhanced impermeability, which stems from the refinement and pore-blocking effect of the composite material. Particularly noteworthy is the successful at imparting conductivity to the conventionally insulating UHPC, with a 5-6 order of magnitude reduction in volume resistivity. This is primarily attributed to the continuous conductive network composed of nitrogen-doped carbon and high-entropy alloy nanoparticles in the composite material. This characteristic gives UHPC the potential for application in intelligent fields such as snow melting and de-icing, electromagnetic shielding, or structural health monitoring.

[0137] In contrast, Comparative Examples 1 and 2, due to their incomplete structures, were far inferior to the materials in the examples in terms of mechanical reinforcement, durability improvement, and functional attribution. Comparative Example 3, as a traditional cobalt / carbon material, has a simple structure; the cobalt nanoparticles are prone to aggregation and have weak bonding with the carbon substrate, resulting in limited reinforcement in UHPC. Its ability to block chloride ion migration is not significantly improved, and it is almost impossible to construct an effective conductive pathway. Its volume resistivity is similar to the blank group, and it cannot impart conductive functionality to the UHPC. This again confirms the crucial role of a complete three-level composite structure in achieving high performance and multifunctionality in UHPC.

[0138] In summary, the carbon nanocomposites prepared in Examples 1-3 exhibit comprehensive, synergistic, and significant technical advantages in three dimensions: material microstructure, electrocatalytic performance, and UHPC-enhanced modification effect. Systematic characterization and testing data indicate that their superior performance stems from the multi-level composite structure constructed through integrated design. This structure comprises a nitrogen-doped ordered mesoporous carbon substrate, in-situ cobalt nanoparticles, and high-entropy alloy nanoparticles. This design not only achieves uniform nanoscale composite and spatial confinement of each component but also forms a stable interfacial bond and optimized electronic structure through strong Co-Nx bonding and an alloying mechanism centered on in-situ cobalt. Consequently, the material simultaneously achieves high specific surface area, well-developed ordered channels, excellent electronic conductivity, tunable catalytically active surface, and outstanding chemical and long-term structural stability. Based on its inherent advantages of integration, this carbon nanocomposite material can simultaneously meet the stringent requirements of both high-end electrocatalysis and advanced ultra-high performance concrete for core materials. In electrocatalysis, the material exhibits high sensitivity, low detection limit, wide linear range, and excellent signal stability and reproducibility. In UHPC, the material demonstrates significant mechanical enhancement, improved durability, and potential for multifunctionality such as conductivity. All comparative materials, lacking the key component of this tertiary structure, showed a regular and systematic decline in performance in both application tests. This comparative result objectively confirms the necessity and effectiveness of integrating a nitrogen-doped carbon substrate, cobalt nanoparticle nucleation centers, and a high-entropy alloy active phase into a single composite for achieving multifunctionality and high performance.

[0139] According to the embodiments of this application, a high-catalytic-performance carbon nanocomposite material, its preparation method, and its application are proposed. This invention integrates a nitrogen-doped ordered mesoporous carbon substrate, in-situ cobalt nanoparticles, and a high-entropy alloy active phase. The nitrogen-doped ordered mesoporous carbon substrate provides a highly conductive framework and robust metal anchoring points. The in-situ generated cobalt nanoparticles are uniformly dispersed and serve as key nucleation centers for subsequent alloying. The multi-element high-entropy alloy phase formed on this basis significantly optimizes the physicochemical properties of the composite material surface through lattice distortion and multi-element synergistic effects. This multi-level composite structure design enables the carbon nanocomposite material to exhibit outstanding high catalytic performance and multifunctional characteristics: in the field of electrocatalysis, the material possesses high catalytic activity, rapid electron transport capability, and excellent structural stability, making it suitable for high-sensitivity and high-selectivity target analyte detection; in the field of ultra-high performance concrete (UHPC), this material can serve as a highly efficient multifunctional additive, synergistically improving the mechanical properties and durability of UHPC through nano-reinforcement, pore structure regulation, and conductive network construction, and endowing it with emerging functional potential such as conductivity and intelligent sensing. The preparation method uses waste biomass such as forage as a carbon source, combining hard template method and microwave-assisted technology. The process route is simple, the conditions are mild, the yield is high, and the cost is controllable, reflecting the green and sustainable concept of high-value utilization of resources. This addresses the problems of insufficient utilization of catalytic active sites, poor inter-component synergy, difficulty in uniformly loading and stably anchoring high-entropy alloy active phases in carbon matrices, high preparation costs of existing materials, and difficulty in balancing high catalytic performance and excellent multifunctionality. It aims to simultaneously meet the composite needs of high-performance core materials in the fields of electrocatalysis and advanced engineering materials.

[0140] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

[0141] The present application and its embodiments have been described above. This description is not restrictive, and the actual application is not limited thereto. In conclusion, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of this application, such design should fall within the protection scope of this application.

Claims

1. A high-catalytic-performance carbon nanocomposite material, characterized in that, include: Nitrogen-doped ordered mesoporous carbon substrates; Cobalt nanoparticles are generated in situ and loaded onto the surface and pores of the ordered mesoporous carbon substrate. High-entropy alloy nanoparticles loaded on the ordered mesoporous carbon substrate and cobalt nanoparticles, wherein the cobalt nanoparticles serve as nucleation centers, and they diffuse and alloy with other added metal elements, such that the cobalt element in the high-entropy alloy nanoparticles is partially derived from the cobalt nanoparticles. The high-entropy alloy nanoparticles are composed of five metal elements: iron, cobalt, nickel, copper, and chromium. The ratio of the sum of the masses of the nitrogen-doped ordered mesoporous carbon substrate and the cobalt nanoparticles to the total mass of the high-entropy alloy nanoparticles is (0.8-3.5):

1.

2. The high-catalytic-performance carbon nanocomposite material according to claim 1, characterized in that, The mesoporous structure of the nitrogen-doped ordered mesoporous carbon substrate is formed by template SBA-15.

3. The high-catalytic-performance carbon nanocomposite material according to claim 1, characterized in that, The nitrogen element in the nitrogen doping is derived from the polymerization and pyrolysis of dopamine.

4. A method for preparing a high-catalytic-performance carbon nanocomposite material as described in any one of claims 1-3, characterized in that, Includes the following steps: Step 1: After crushing and grinding the forage raw material, wash it with distilled water to obtain forage powder. Mix it with sodium hydroxide solution at a solid-liquid ratio of 1:8-12, heat it in an oil bath at 85-95℃ for 1-2 hours, centrifuge to obtain a supernatant rich in lignin, add acid to the supernatant to adjust the pH value to 2.5-3.5, stir slowly to precipitate lignin, obtain acid-precipitated lignin, dry and crush it, disperse it in deionized water, adjust the pH value to 9.0-11.0 with sodium hydroxide solution, add sodium sulfite, and carry out sulfonation reaction at 105-115℃ for 3-4 hours under closed conditions. Dry the reaction product to obtain sodium lignin sulfonate. Step 2: Disperse the SBA-15 template in a tris(hydroxymethyl)aminomethane buffer solution with a pH of 8.0-9.0, then add dopamine, sodium lignosulfonate and cobalt nitrate hexahydrate in sequence. After mixing evenly, let it stand at room temperature in the dark for 12-36 hours. Then add a methanol solution of 1,2-dimethylimidazole and react in a microwave reactor at 95-105℃ for 2-5 minutes to quickly complete coordination and assembly. After the reaction is completed, centrifuge the mixture, wash the obtained solid with methanol and dry it at 50-70℃ to obtain the solid precursor. Step 3: The solid precursor is placed in an inert atmosphere and heated to 750-850℃ at a heating rate of 1-5℃ / min and calcined for 2-4 hours. After natural cooling, the calcined product is placed in an aqueous sodium hydroxide solution and heated at 75-85℃ for 2-3 hours to remove the template. Then, solid-liquid separation is performed. The obtained solid is washed and dried to obtain nitrogen-doped ordered mesoporous carbon loaded with cobalt nanoparticles. Step 4: The nitrogen-doped ordered mesoporous carbon is uniformly dispersed in ethanol, and a chloride solution containing five metal elements (iron, cobalt, nickel, copper, and chromium) is added to it. The mixture is stirred at room temperature for 20-28 hours for impregnation. Then, the mixture is evaporated at 70-85°C to remove the solvent, resulting in a dry intermediate. The intermediate is then heated to 850-950°C at a heating rate of 5-15°C / min and calcined for 1-3 hours in a reducing atmosphere or a reducing / inert mixed atmosphere. During this high-temperature reduction and alloying process, the added metal elements diffuse and fuse with some in-situ cobalt nanoparticles to form high-entropy alloy nanoparticles on the carbon substrate. After cooling, a carbon nanocomposite material is obtained. The high-entropy alloy nanoparticles are characterized by X-ray diffraction as a single face-centered cubic solid solution phase.

5. The method for preparing the high-catalytic-performance carbon nanocomposite material according to claim 4, wherein in step two, the mass ratios of the SBA-15 template to the dopamine, the sodium lignosulfonate, and the cobalt nitrate hexahydrate are 1:(1.2-1.8), 1:(2.5-3.5), and 1:(0.25-0.35), respectively, and the molar ratio of 1,2-dimethylimidazole to cobalt nitrate hexahydrate is (2-4):

1.

6. The method for preparing the high-catalytic-performance carbon nanocomposite material according to claim 4, characterized in that, In step four, the concentration of the metal chloride in the chloride solution is 20-30 mg / mL, the molar ratio of the five metal elements (iron, cobalt, nickel, copper, and chromium) is (0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2):(0.8-1.2), and the reducing / inert mixed atmosphere is a mixture of hydrogen and argon.

7. An application of a high-catalytic-performance carbon nanocomposite material as described in any one of claims 1-3, characterized in that, It is applied in the field of electrocatalysis.

8. An application of a high-catalytic-performance carbon nanocomposite material as described in any one of claims 1-3, characterized in that, It is used in the preparation of ultra-high performance concrete as a functional additive.

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