Carbon material rich in intrinsic defect as well as preparation method and application thereof

Abstract

The invention discloses a carbon material rich in intrinsic defects as well as a preparation method and application thereof, and belongs to the technical field of catalysts, fullerene or fullerene derivative carbon cages adopted by the invention have a pi conjugated structure, so that relatively strong pi-pi interaction force exists among molecules. Fullerene or a fullerene derivative is used as a raw material, a macroscopic crystalline material, namely a fullerene condensed state precursor, is obtained through self-assembly based on intermolecular acting force, the fullerene condensed state precursor is subjected to pre-etching treatment through oxygen plasma, surface modification is conducted on the fullerene condensed state precursor, and the fullerene or fullerene derivative is obtained. The preparation method comprises the following steps: preparing a fullerene condensed state precursor, performing two-stage temperature programming heat treatment of low-temperature pre-etching treatment and high-temperature roasting in ZnCl2 molten salt, endowing the fullerene condensed state precursor with five-membered ring topological defects and carbon intrinsic defects of boundaries and curvatures, so as to obtain the carbon material rich in intrinsic defects, and endowing the carbon material with good electro-catalytic performance by the intrinsic defect sites.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to an intrinsically defect-rich carbon material, its preparation method, and its application. Background Technology

[0002] Highly crystallizable steady-state sp 2 Conjugated carbon materials, such as carbon nanotubes and graphene, possess excellent electrical and thermal conductivity and chemical stability. However, their highly symmetric electronic structure leads to poor chemical reactivity. In recent years, improvements in the catalytic performance of carbon materials due to intrinsic defects in carbon, such as topological defects, boundaries, and curvature of five-membered rings, have been gradually discovered. Studies have shown that compared to six-membered carbon rings, carbon atoms in five-membered rings have higher electron densities and stronger adsorption and activation capabilities for oxygen molecules, effectively promoting the oxygen reduction reaction (ORR), i.e., exhibiting ORR catalytic activity. Furthermore, carbon atoms located at the boundaries, due to coordination unsaturation and asymmetric electron density, also exhibit good ORR catalytic activity. These intrinsic defects break the symmetry of the electron density distribution of carbon materials or endow them with certain electronic spin characteristics, significantly improving their catalytic performance. Therefore, the development of doped non-metallic carbon-based electrocatalytic materials based on intrinsic defect active sites has become a research hotspot.

[0003] Fullerenes, the third allotrope of carbon discovered after graphite and diamond, have been extensively studied in various fields due to their unique physicochemical properties, including excellent electron-donating and accepting capabilities and high chemical stability. Fullerene molecules possess a unique carbon cage structure composed of alternating five-membered and six-membered carbon rings. Under high-temperature heat treatment, the fullerene carbon cage structure collapses and breaks down, forming fine carbon fragments. These fragmented intermediates recombine to form metastable fullerene-derived carbon materials. During this process, a large number of the original five-membered carbon rings of the fullerene are preserved, while abundant boundary defects are generated, providing numerous intrinsic defect active sites for the fullerene-derived carbon materials. Furthermore, a large number of positive Gaussian curvature microstructures are formed in the fullerene-derived carbon, inducing local strain, altering the electronic structure, thereby enhancing electron transfer performance and accelerating reaction kinetics. Therefore, metastable fullerene-derived carbon can integrate all these advantageous factors into a single system, thus becoming a promising doped non-metallic carbon-based catalyst.

[0004] Among the currently disclosed technologies, carbon dioxide oxidation etching, water vapor oxidation etching, and nitrogen doping and denitrification are common methods for constructing intrinsically defective carbon materials. By introducing oxidants to react with carbon atoms or by doping with pyridine nitrogen atoms and then removing them, the intrinsic defect density of carbon materials can be increased. However, carbon materials constructed by these methods still face technical challenges such as low and uncontrollable intrinsic defect density and insufficient catalytic activity. Summary of the Invention

[0005] This invention provides an intrinsically defect-rich carbon material, its preparation method, and its application. It effectively solves the technical problems of low and uncontrollable defect density and insufficient catalytic activity of existing methods for constructing intrinsic defects in carbon materials. This invention uses condensed-state materials self-assembled by fullerenes or their derivatives as precursors. By regulating the fullerene-based condensed-state precursors, and through sequential oxygen plasma modification, zinc chloride molten salt pre-etching, and molecular pyrolysis reconstruction, metastable intrinsically defect-rich carbon materials are obtained, exhibiting superior electrocatalytic performance.

[0006] The first objective of this invention is to provide a method for preparing intrinsically defect-rich carbon materials, comprising the following steps: Using fullerenes or fullerene derivatives as raw materials, they are dissolved in a good solvent to obtain a fullerene solution. A poor solvent is then added to the fullerene solution, and the fullerenes or fullerene derivatives are self-assembled into fullerene micro / nano structures through a liquid-liquid interface deposition method to obtain a fullerene-based condensed state precursor.

[0007] The fullerene-based condensed-state precursor was functionalized using oxygen plasma with a power of 100W~150W to obtain a surface-modified fullerene-based condensed-state precursor.

[0008] Under a protective atmosphere, at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 were mixed in a ceramic boat, and the temperature was raised to 280°C~300°C in a tube furnace under programmed control and held for a certain time to pre-etch the modified precursor.

[0009] Under a protective atmosphere and normal pressure, the temperature is further increased to a higher temperature through programmed control to calcine the fullerene-based condensed precursor, which is endowed with carbon intrinsic defects in the topological defects, boundaries, and curvature of the five-membered ring. The product is then washed with water to obtain carbon material rich in intrinsic defects.

[0010] As a preferred embodiment, the method for preparing the intrinsically defect-rich carbon material is characterized in that the oxygen plasma has an oxygen flow rate of 20 sccm, a pressure of 0.1 Torr to 0.2 Torr, and a re-etching time of 3 min to 5 min.

[0011] As a preferred embodiment, the method for preparing the intrinsically defect-rich carbon material is characterized in that the mass ratio of the modified fullerene-based condensed precursor to ZnCl2 molten salt is 1:3, and the temperature is raised from room temperature to 280°C~300°C at a rate of 5°C / min and held for 30min~60min.

[0012] As a preferred embodiment, the method for preparing the intrinsically defective carbon material is characterized in that the ratio of the amount of fullerene or fullerene derivative, good solvent and poor solvent is 1 mg to 2 mg: 1 mL: 2 mL.

[0013] As a preferred embodiment, the method for preparing the intrinsically defect-rich carbon material is characterized in that the fullerene is C 60 C 70 Or C 60 With C 70 A mixture of; the fullerene derivative is C 60 The pyrrolidine derivative; the good solvent is toluene, m-xylene, mesitylene, or carbon disulfide; the poor solvent is isopropanol, n-butanol, tert-butanol, or n-heptanol.

[0014] As a preferred embodiment, the method for preparing the intrinsically defect-rich carbon material is characterized in that the method for preparing the fullerene-based condensed-state precursor specifically comprises: dissolving fullerene or a fullerene derivative in a good solvent to obtain a fullerene solution; adding a poor solvent to the fullerene solution to form an interface between the good solvent and the poor solvent to obtain a boundary solution; and allowing the boundary solution to stand at room temperature for spontaneous growth to obtain the fullerene-based condensed-state precursor.

[0015] As a preferred embodiment, the method for preparing the intrinsically defect-rich carbon material is characterized in that the programmed temperature rise calcination after holding at 280°C to 300°C specifically involves calcining at a rate of 5°C / min from room temperature to 600°C to 800°C for 1 to 2 hours.

[0016] A second objective of this invention is to provide an intrinsically defect-rich carbon material prepared by any of the methods described above.

[0017] A third objective of this invention is to provide an application of the aforementioned intrinsically defect-rich carbon material in catalytic oxygen reduction reactions.

[0018] A fourth objective of this invention is to provide an application of the aforementioned intrinsically defect-rich carbon material in zinc-air battery devices.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a method for preparing intrinsically defect-rich carbon materials. The fullerene or fullerene derivative carbon cages used in this invention have a π-conjugated structure, resulting in strong π-π interactions between molecules. Therefore, this invention uses fullerene or fullerene derivatives as raw materials and self-assembles based on intermolecular forces to obtain macroscopic crystalline materials, namely fullerene-based condensed-state precursors. The fullerene-based condensed-state precursors are functionalized using oxygen plasma to obtain surface-modified fullerene-based condensed-state precursors. These precursors are then subjected to low-temperature pre-etching and high-temperature calcination in ZnCl2 molten salt, followed by water washing to obtain intrinsically defect-rich carbon materials. In the above treatment scheme, oxygen plasma is used for surface modification, and the oxygen plasma generates high-energy oxygen ions and oxygen free radicals under the action of a high-frequency electric field. These reactive oxygen species bombard the surface of the fullerene-based condensed precursor, breaking carbon-carbon bonds and reacting with the fullerene molecules to form polar oxygen-containing functional groups. These functional groups promote the dispersion of the fullerene-based condensed precursor in the polar molten salt liquid during subsequent ZnCl2 molten salt treatment, improving wettability. These functional groups also decompose during subsequent high-temperature treatment, leaving more intrinsic defects. The bombardment by high-energy ions also causes local structural deformation of the fullerene carbon cage, reducing its thermal stability and promoting subsequent pyrolysis. Following this, low-temperature pre-etching in ZnCl2 molten salt, due to the Lewis acidity of ZnCl2, will cause Lewis acid-base interactions with the π-electron cloud of the fullerene, affecting the electronic structure of the fullerene and further reducing the thermal stability of the carbon cage. In addition, ZnCl2 etching creates more microporous structures, increasing defect density and thus improving catalytic activity. Finally, after further pyrolysis and reconstruction at even higher temperatures, the carbon cage structure of the fullerene or its derivatives fractures due to the high temperature, producing carbon fragment structures. These carbon fragments retain the original five-membered ring topological defects in the fullerene carbon cage, while also generating abundant boundary and curvature defects, resulting in metastable carbon materials rich in intrinsic defects. These intrinsic defect sites endow the fullerene-derived carbon materials with excellent electrocatalytic performance. Compared with traditional oxidation etching and dopant removal methods, this invention is simple to operate, and the resulting fullerene-derived carbon materials have high intrinsic defect density, controllable macroscopic morphology, and superior electrocatalytic performance, effectively avoiding the technical difficulties of complex procedures and low and uncontrollable intrinsic defect density in traditional methods.

[0020] Electrochemical test results show that the fullerene-derived carbon material prepared in this invention exhibits outstanding ORR catalytic performance in alkaline electrolytes. When used as a positive electrode catalyst in zinc-air batteries, it demonstrates excellent electrochemical performance, including stable open-circuit voltage, high energy density, and discharge voltage. The fibrous C prepared in Example 1 of this invention... 60 The ORR half-wave potential of the derived carbon reaches 0.80V. RHE It is significantly higher than the C of Comparative Example 1. 60 The half-wave potential of the derived carbon material is 0.72V. RHEIt exhibits high four-electron selectivity and excellent cycle stability, outperforming many reported fullerene-derived carbon catalysts. Simultaneously, it contains fibrous C... 60 The carbon-derived zinc-air battery can provide a voltage of over 1V, which can stably power a red LED screen for a long time, demonstrating its high application potential in the field of energy storage / conversion. Attached Figure Description

[0021] Figure 1 The C prepared in Example 1 of this invention 60 Scanning electron microscope images of micro / nano structures.

[0022] Figure 2 The C prepared in Example 1 of this invention 60 Scanning electron microscope image of the derived carbon.

[0023] Figure 3 It is C prepared in Example 2 of this invention. 70 Scanning electron microscope images of micro / nano structures.

[0024] Figure 4 The C prepared in Example 3 of this invention 60 Scanning electron microscope images of micro / nano structures.

[0025] Figure 5 The C prepared in Example 4 of this invention 60 Scanning electron microscope images of micro / nano structures.

[0026] Figure 6 The C prepared in Example 5 of this invention 60 +C 70 Scanning electron microscope images of mixture micro / nano structures.

[0027] Figure 7 This is a scanning electron microscope image of the micro / nano structure of N-methyl

[60] fullerene pyrrolidine prepared in Example 6 of this invention.

[0028] Figure 8 This is a scanning electron microscope image of the N-methyl

[60] fullerene pyrrolidine-derived carbon prepared in Example 6 of this invention.

[0029] Figure 9 The C provided in Comparative Example 1 of this invention is untreated with oxygen plasma and ZnCl2. 60 The prepared fullerene-derived carbon material and the C prepared in Example 1 60 Linear sweep voltammetry curves of derived carbon.

[0030] Figure 10 It is C prepared using Example 1 of the present invention. 60 Open-circuit potential curves of zinc-air batteries assembled with derived carbon.

[0031] Figure 11 It is C prepared using Example 1 of the present invention. 60 Optical photograph of a zinc-air battery assembled from derived carbon powering an LED screen. Detailed Implementation

[0032] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention will be further described below with reference to specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the invention. Unless otherwise specified, the following test methods and detection methods are conventional methods; unless otherwise specified, the reagents and raw materials are commercially available.

[0033] Currently available methods for constructing carbon materials with intrinsic defects—such as carbon dioxide oxidation etching, water vapor oxidation etching, and nitrogen doping and denitrification—effectively increase the intrinsic defect density of carbon materials by introducing oxidants to react with carbon atoms or by incorporating nitrogen heteroatoms followed by removal. However, these methods suffer from technical challenges such as low and uncontrollable intrinsic defect density and insufficient catalytic activity in the carbon materials. To address these technical problems, this invention provides a fullerene-derived carbon material, its preparation method, and its applications.

[0034] The technical solution of the present invention will be analyzed and described in detail below.

[0035] This invention first provides a method for preparing fullerene-derived carbon materials, comprising the following steps: S1, using fullerene or fullerene derivatives as raw materials, dissolving them in a good solvent to obtain a fullerene solution, adding a poor solvent to the fullerene solution, and using a liquid-liquid interface deposition method, fullerene or fullerene derivatives self-assemble to form a fullerene micro / nano structure, thus obtaining a fullerene-based condensed state precursor.

[0036] S2, using oxygen plasma with a power of 100W~150W, the fullerene-based condensed-state precursor is functionalized to obtain a surface-modified fullerene-based condensed-state precursor.

[0037] S3, under a protective atmosphere and at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 are mixed in a ceramic boat, and the modified precursor is pre-etched in a tube furnace by program-controlled heating to 280°C~300°C and holding for a certain time.

[0038] S4, under a protective atmosphere and normal pressure, is further calcined to a higher temperature through programmed temperature control to impart carbon intrinsic defects to the five-membered ring topological defects, boundaries, and curvature of the fullerene-based condensed state precursor. The product is then washed with water to obtain intrinsically defect-rich carbon materials.

[0039] In the above technical solution, fullerenes or fullerene derivatives are used as raw materials. Based on intermolecular forces, they self-assemble to obtain macroscopic crystalline materials, namely fullerene-based condensed-state precursors. These precursors are then functionalized using oxygen plasma to obtain surface-modified fullerene-based condensed-state precursors. These precursors are then subjected to low-temperature pre-etching and high-temperature calcination in ZnCl2 molten salt, followed by water washing to obtain intrinsically defect-rich carbon materials. In this treatment scheme, oxygen plasma is used for surface modification. Under the action of a high-frequency electric field, the oxygen plasma generates high-energy oxygen ions and oxygen free radicals. These active oxygen species bombard the surface of the fullerene-based condensed-state precursors, breaking carbon-carbon bonds and reacting with fullerene molecules to form polar oxygen-containing functional groups. These functional groups promote the dispersion of the fullerene-based condensed-state precursors in the polar molten salt liquid during subsequent ZnCl2 molten salt treatment, improving wettability. These functional groups also decompose during subsequent high-temperature treatment, leaving behind more intrinsic defects. High-energy ion bombardment can also cause local structural deformation of the fullerene carbon cage, reducing its thermal stability and promoting subsequent pyrolysis and cracking. Next, low-temperature pre-etching is performed in molten ZnCl2 salt. Due to the Lewis acidity of ZnCl2, it will interact with the π-electron cloud of the fullerene through a Lewis acid-base interaction, affecting the electronic structure of the fullerene and further reducing the thermal stability of the carbon cage. In addition, ZnCl2 etching creates more microporous structures, increasing defect density and thus improving catalytic activity. Finally, a higher-temperature pyrolysis and reconstruction process occurs, causing the carbon cage structure of the fullerene or its derivatives to crack and generate carbon fragment structures. These carbon fragments retain the original five-membered ring topological defects in the fullerene carbon cage, while also generating abundant boundary and curvature defects, resulting in metastable carbon materials rich in intrinsic defects. These intrinsic defect sites endow the fullerene-derived carbon materials with excellent electrocatalytic performance.

[0040] The technical effects of the present invention will be described below with reference to specific embodiments and comparative examples.

[0041] Example 1 A method for preparing a fullerene-derived carbon material includes the following steps: S1, first, 2mg of C 60 Dissolve in 2 mL of toluene and sonicate for 20 min to allow C to dissolve. 60 The fullerene solution was obtained by fully dissolving the powder. Then, 4 mL of isopropanol was slowly injected into the fullerene solution along the wall of the sample vial. The mixture was allowed to stand at room temperature for 24 hours to grow, resulting in a dispersion. The dispersion was then subjected to simple vacuum filtration and repeated washing with isopropanol. The filtration membrane and powder were then placed in a vacuum drying oven and dried at 60°C for 24 hours. After complete drying, the powder was scraped off to obtain the fullerene powder, i.e., the fullerene-based condensed-state precursor, denoted as C. 60 Micro-nano structures.

[0042] S2, using 150W oxygen plasma, the fullerene-based condensed-state precursor is functionalized by treating it with an oxygen flow rate of 20 sccm and an oxygen pressure of 0.1 Torr for 3 min to obtain a surface-modified fullerene-based condensed-state precursor.

[0043] S3. Under an argon atmosphere and at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 were mixed in a ceramic boat at a mass ratio of 1:3. The mixture was then heated to 280°C in a tube furnace at a heating rate of 5°C / min and held for 60 min to pre-etch the surface-modified fullerene-based condensed precursor.

[0044] S4, under a protective atmosphere and normal pressure, the temperature was further increased from 280°C to 800°C at a heating rate of 5°C / min and held for 2 hours. After the program was completed, the temperature was allowed to drop naturally. The product was washed with water to obtain a fullerene-derived carbon material, denoted as C. 60 Derived carbon.

[0045] Example 2 A method for preparing a fullerene-derived carbon material includes the following steps: S1, first, 4mg of C 70 Dissolve in 2 mL of toluene and sonicate for 20 min to allow C to dissolve. 70 The fullerene solution was obtained by fully dissolving the powder. Then, 4 mL of isopropanol was slowly injected into the fullerene solution along the wall of the sample vial. The mixture was allowed to stand at room temperature for 24 hours to grow, resulting in a dispersion. The dispersion was then subjected to simple vacuum filtration and repeated washing with isopropanol. The filtration membrane and powder were then placed in a vacuum drying oven and dried at 60°C for 24 hours. After complete drying, the powder was scraped off to obtain the fullerene powder, i.e., the fullerene-based condensed-state precursor, denoted as C. 70 Micro-nano structures.

[0046] S2, using 150W oxygen plasma, the fullerene-based condensed-state precursor is functionalized by treating it with an oxygen flow rate of 20 sccm and an oxygen pressure of 0.1 Torr for 3 min to obtain a surface-modified fullerene-based condensed-state precursor.

[0047] S3. Under an argon atmosphere and at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 were mixed in a ceramic boat at a mass ratio of 1:3. The mixture was then heated to 280°C in a tube furnace at a heating rate of 5°C / min and held for 60 min to pre-etch the surface-modified fullerene-based condensed precursor.

[0048] S4, under a protective atmosphere and normal pressure, the temperature was further increased from 280°C to 800°C at a heating rate of 5°C / min and held for 2 hours. After the program was completed, the temperature was allowed to drop naturally. The product was washed with water to obtain a fullerene-derived carbon material, denoted as C. 70 Derived carbon.

[0049] Example 3 A method for preparing a fullerene-derived carbon material includes the following steps: S1, first, 2mg of C 60 Dissolve in 2 mL of m-xylene, sonicate for 20 min, so that C 60 The fullerene solution was obtained by fully dissolving the powder. Then, 4 mL of isopropanol was slowly injected into the fullerene solution along the wall of the sample vial. The mixture was allowed to stand at room temperature for 24 hours to grow, resulting in a dispersion. The dispersion was then subjected to simple vacuum filtration and repeated washing with isopropanol. The filtration membrane and powder were then placed in a vacuum drying oven and dried at 60°C for 24 hours. After complete drying, the powder was scraped off to obtain the fullerene powder, i.e., the fullerene-based condensed-state precursor, denoted as C. 60 Micro-nano structures.

[0050] S2, using 150W oxygen plasma, the fullerene-based condensed-state precursor is functionalized by treating it with an oxygen flow rate of 20 sccm and an oxygen pressure of 0.1 Torr for 3 min to obtain a surface-modified fullerene-based condensed-state precursor.

[0051] S3. Under an argon atmosphere and at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 were mixed in a ceramic boat at a mass ratio of 1:3. The mixture was then heated to 280°C in a tube furnace at a heating rate of 5°C / min and held for 60 min to pre-etch the surface-modified fullerene-based condensed precursor.

[0052] S4, under a protective atmosphere and normal pressure, the temperature was further increased from 280°C to 800°C at a heating rate of 5°C / min and held for 2 hours. After the program was completed, the temperature was allowed to drop naturally. The product was washed with water to obtain a fullerene-derived carbon material, denoted as C. 60 Derived carbon.

[0053] Example 4 A method for preparing a fullerene-derived carbon material includes the following steps: S1, first, 2mg of C 60 Dissolve in 2 mL of toluene and sonicate for 20 min to allow C to dissolve. 60The solution was fully dissolved to obtain a fullerene solution. Then, 4 mL of n-butanol was slowly injected into the fullerene solution along the wall of the sample vial. The mixture was allowed to stand at room temperature for 24 hours to grow, resulting in a dispersion. The dispersion was then subjected to simple vacuum filtration and repeated washing with isopropanol. The filtration membrane and powder were then placed in a vacuum drying oven and dried at 60°C for 24 hours. After complete drying, the powder was scraped off to obtain the fullerene powder, i.e., the fullerene-based condensed-state precursor, denoted as C. 60 Micro-nano structures.

[0054] S2, using 150W oxygen plasma, the fullerene-based condensed-state precursor is functionalized by treating it with an oxygen flow rate of 20 sccm and an oxygen pressure of 0.1 Torr for 3 min to obtain a surface-modified fullerene-based condensed-state precursor.

[0055] S3. Under an argon atmosphere and at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 were mixed in a ceramic boat at a mass ratio of 1:3. The mixture was then heated to 280°C in a tube furnace at a heating rate of 5°C / min and held for 60 min to pre-etch the surface-modified fullerene-based condensed precursor.

[0056] S4, under a protective atmosphere and normal pressure, the temperature was further increased from 280°C to 800°C at a heating rate of 5°C / min and held for 2 hours. After the program was completed, the temperature was allowed to drop naturally. The product was washed with water to obtain a fullerene-derived carbon material, denoted as C. 60 Derived carbon.

[0057] Example 5 A method for preparing a fullerene-derived carbon material includes the following steps: S1, first, 2mg of C 60 and 2mg of C 70 Dissolve in 2 mL of toluene and sonicate for 20 min to allow C to dissolve. 60 and C 70 The fullerene solution was obtained by fully dissolving the powder. Then, 4 mL of isopropanol was slowly injected into the fullerene solution along the wall of the sample vial. The mixture was allowed to stand at room temperature for 24 hours to grow, resulting in a dispersion. The dispersion was then subjected to simple vacuum filtration and repeated washing with isopropanol. The filtration membrane and powder were then placed in a vacuum drying oven and dried at 60°C for 24 hours. After complete drying, the powder was scraped off to obtain the fullerene powder, i.e., the fullerene-based condensed-state precursor, denoted as C. 60 +C 70 Hybrid micro / nano structures.

[0058] S2, using 150W oxygen plasma, the fullerene-based condensed-state precursor is functionalized by treating it with an oxygen flow rate of 20 sccm and an oxygen pressure of 0.1 Torr for 3 min to obtain a surface-modified fullerene-based condensed-state precursor.

[0059] S3. Under an argon atmosphere and at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 were mixed in a ceramic boat at a mass ratio of 1:3. The mixture was then heated to 280°C in a tube furnace at a heating rate of 5°C / min and held for 60 min to pre-etch the surface-modified fullerene-based condensed precursor.

[0060] S4, under a protective atmosphere and normal pressure, the temperature was further increased from 280°C to 800°C at a heating rate of 5°C / min and held for 2 hours. After the program was completed, the temperature was allowed to drop naturally. The product was washed with water to obtain a fullerene-derived carbon material, denoted as C. 60 +C 70 Derived carbon.

[0061] Example 6 A method for preparing a fullerene-derived carbon material includes the following steps: S1. First, 2 mg of N-methyl

[60] fullerene pyrrolidine was dissolved in 2 mL of toluene and sonicated for 20 min to fully dissolve the N-methyl

[60] fullerene pyrrolidine and obtain a fullerene solution. Then, 4 mL of isopropanol was slowly injected into the fullerene solution along the sample bottle wall and allowed to stand at room temperature for 24 h to grow, resulting in a dispersion. The dispersion was then simply filtered and repeatedly washed with isopropanol. After that, the filter membrane and the powder were placed in a vacuum drying oven and dried at 60°C for 24 h. After it was completely dried, it was scraped off to obtain the fullerene powder, namely the N-methyl

[60] fullerene pyrrolidine fullerene-based condensed state precursor, denoted as the N-methyl

[60] fullerene pyrrolidine micro / nano structure.

[0062] S2, using 150W oxygen plasma, the fullerene-based condensed-state precursor is functionalized by treating it with an oxygen flow rate of 20 sccm and an oxygen pressure of 0.1 Torr for 3 min to obtain a surface-modified fullerene-based condensed-state precursor.

[0063] S3. Under an argon atmosphere and at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 were mixed in a ceramic boat at a mass ratio of 1:3. The mixture was then heated to 280°C in a tube furnace at a heating rate of 5°C / min and held for 60 min to pre-etch the surface-modified fullerene-based condensed precursor.

[0064] S4, under a protective atmosphere and normal pressure, continue to heat from 280°C to 800°C at a heating rate of 5°C / min and hold for 2 hours. After the program is completed, cool down naturally. The product is washed with water to obtain fullerene-derived carbon material, denoted as N-methyl

[60] fullerene-pyrrolidine-derived carbon.

[0065] To further illustrate the technical effects of the present invention, comparative examples are also provided, as follows: Comparative Example 1 The difference from Example 1 is that, instead of using oxygen plasma and ZnCl2 molten salt for etching, the fullerene-based condensed precursor is directly pyrolyzed in a tube furnace.

[0066] A method for preparing a fullerene-derived carbon material includes the following steps: S1, first, 2mg of C 60 Dissolve in 2 mL of toluene and sonicate for 20 min to allow C to dissolve. 60 The fullerene solution was obtained by fully dissolving the powder. Then, 4 mL of isopropanol was slowly injected into the fullerene solution along the wall of the sample vial. The mixture was allowed to stand at room temperature for 24 hours to grow, resulting in a dispersion. The dispersion was then subjected to simple vacuum filtration and repeated washing with isopropanol. The filtration membrane and powder were then placed in a vacuum drying oven and dried at 60°C for 24 hours. After complete drying, the powder was scraped off to obtain the fullerene powder, i.e., the fullerene-based condensed-state precursor, denoted as C. 60 Micro-nano structures.

[0067] S2, the fullerene powder is placed in a tube furnace and heated from room temperature to 900°C at a rate of 5°C / min under argon gas protection, and held at that temperature for 2 hours. After the process is completed, it is allowed to cool naturally to obtain the fullerene-derived carbon material, denoted as C. 60 Derived carbon.

[0068] The morphology and properties of the fullerene-derived carbon materials prepared in Examples 1 to 6 and Comparative Example 1 of this invention were tested, and the results are as follows.

[0069] Figure 1 The C provided in Embodiment 1 of this invention 60 Scanning electron microscope images of micro / nano structures, by Figure 1 The sample exhibits a uniform fibrous morphology, with individual fibers ranging in diameter to ~500 nm and a smooth surface. This indicates that C can be synthesized using a liquid-liquid interface method with a solvent combination of toluene and isopropanol. 60 They self-assemble into fibrous structures.

[0070] Figure 2 The C prepared in Example 1 of this invention 60 Scanning electron microscope images of derived carbon, by Figure 2It can be seen that the sample still maintains a uniform fibrous morphology, while compared to Figure 1 fibrous C in 60 The precursor exhibits a slightly reduced diameter, a rougher surface, and some internal pores. This indicates that during etching and pyrolysis, C... 60 Some sublimation occurs, maintaining the original structure while generating a rich porous structure.

[0071] Figure 3 The C provided in Embodiment 2 of the present invention 70 Scanning electron microscopy (SEM) images of the micro / nano structures reveal a uniform bulk morphology with a size of ~400 nm. This indicates that different fullerene molecules can assemble into different micro / nano structures using a liquid-liquid interface method with the same solvent combination.

[0072] Figure 4 The C provided in Embodiment 3 of the present invention 60 Scanning electron microscopy (SEM) images of the micro / nano structure reveal a unique flower-like structure composed of micrometer rods with a diameter of ~1 µm. Its morphology is similar to that of the C2012 sample prepared in Example 1 using toluene-isopropanol solvent. 60 The micro and nano structures have completely different morphologies, which indicates that different good solvents will lead to completely different microstructures.

[0073] Figure 5 The C provided in Embodiment 4 of the present invention 60 Scanning electron microscope (SEM) images of the micro / nano structure show that the sample exhibits a uniform sheet-like structure with a thickness of approximately 1 µm, which is also significantly different from C. 60 The fiber morphology indicates that different unsuitable solvents will also significantly affect the microstructure of fullerenes.

[0074] Figure 6 C is prepared in Example 5 of this invention. 60 +C 70 Scanning electron microscopy (SEM) images of the mixture's micro / nanostructures reveal that the sample morphology consists of two parts: lamellar and granular structures. This indicates that C0 was simultaneously assembled under the same solvent combination. 60 and C 70 Two fullerene molecules will result in a composite microstructure.

[0075] Figure 7 The image shows a scanning electron microscope (SEM) image of the N-methyl

[60] fullerene pyrrolidine micro / nano structure provided in Example 6 of this invention. As can be seen from the image, the sample is composed of stacked small bulk particles with a size of ~200 nm. This indicates that, through a liquid-liquid interface method, fullerene and fullerene derivative molecules can be assembled into different micro / nano structures under the same solvent combination.

[0076] Figure 8 The image shows a scanning electron microscope (SEM) image of the N-methyl

[60] fullerene pyrrolidine-derived carbon provided in Example 6 of this invention. As can be seen from the image, the derived carbon prepared in Example 6 retains a fine bulk morphology, the bulk size is slightly increased, the surface becomes rough, and the interior is rich in pores. This indicates that during the pyrolysis process, the micro / nano structure of N-methyl

[60] fullerene pyrrolidine undergoes sublimation, maintaining the original structure while generating a rich porous structure.

[0077] Figure 9 The fullerene-derived carbon material prepared in Comparative Example 1 without ZnCl2 molten salt etching and oxygen plasma etching, and the C material from Example 1 are examples of the present invention. 60 The linear sweep voltammetry curves of the derived carbon sample in O2-saturated, 0.1M KOH solution show that the C in Example 1... 60 The half-wave potential and limiting current density of the derived carbon are 0.80 V. RHE and 5.55mA·cm −2 The ORR performance of the fullerene-derived carbon material prepared without ZnCl2 molten salt etching and oxygen plasma etching in Comparative Example 1 is significantly better than that of the material prepared by the same method, namely E. 1 / 2 =0.72V RHE J L =4.96mA·cm −2 This indicates that by assembling fullerene molecules into corresponding micro / nano structures and then subjecting them to ZnCl2 molten salt etching, oxygen plasma etching, and pyrolysis treatment, the catalytic activity of fullerene-derived carbon materials can be effectively enhanced.

[0078] Figure 10 C prepared according to Example 1 of this invention 60 The open-circuit potential curve of the zinc-air battery assembled with derived carbon is shown in the figure. It can be seen that the initial open-circuit potential of the assembled zinc-air battery is as high as 1.43V, and it remains stable over 24 hours, indicating that the C-derived carbon... 60 The derived carbon exhibits excellent long-term cycling stability as a catalyst.

[0079] Figure 11 Therefore, the C provided in Embodiment 1 of the present invention 60 An optical photograph shows a zinc-air battery assembled from carbon-derived components powering an LED screen. The image demonstrates that the battery can provide a voltage exceeding 1V, enabling a stable, long-term power supply for a red LED screen. This indicates that C… 60 Derived carbon catalysts have high potential for practical device applications.

[0080] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing intrinsically defect-rich carbon materials, characterized in that, Includes the following steps: Using fullerene or fullerene derivatives as raw materials, a fullerene solution is obtained by dissolving them in a good solvent. A poor solvent is then added to the fullerene solution, and the fullerene or fullerene derivatives are self-assembled into fullerene micro / nano structures by liquid-liquid interface deposition to obtain a fullerene-based condensed state precursor. The fullerene-based condensed-state precursor was functionalized using oxygen plasma with a power of 100W~150W to obtain a surface-modified fullerene-based condensed-state precursor. Under a protective atmosphere, at room temperature and normal pressure, the modified fullerene-based condensed precursor and ZnCl2 were mixed in a ceramic boat, and the temperature was raised to 280°C~300°C in a tube furnace under programmed control and held for a certain time to pre-etch the modified precursor. Under a protective atmosphere and normal pressure, the temperature is further increased to a higher temperature through programmed control to calcine the fullerene-based condensed precursor, which is endowed with carbon intrinsic defects in the topological defects, boundaries, and curvature of the five-membered ring. The product is then washed with water to obtain carbon material rich in intrinsic defects.

2. The method for preparing intrinsically defect-rich carbon materials according to claim 1, characterized in that, The oxygen plasma has an oxygen flow rate of 20 sccm and a pressure of 0.1 Torr to 0.2 Torr, and the re-etching time is 3 min to 5 min.

3. The method for preparing intrinsically defect-rich carbon materials according to claim 1, characterized in that, The modified fullerene-based condensed precursor and ZnCl2 molten salt were in a mass ratio of 1:3, and the temperature was increased from room temperature to 280°C~300°C at a rate of 5°C / min and held for 30min~60min.

4. The method for preparing intrinsically defect-rich carbon materials according to claim 1, characterized in that, The ratio of the amount of fullerene or fullerene derivative, good solvent and poor solvent is 1 mg to 2 mg: 1 mL: 2 mL.

5. The method for preparing intrinsically defect-rich carbon materials according to claim 1, characterized in that, The fullerene is C 60 C 70 Or C 60 With C 70 A mixture of; the fullerene derivative is C 60 Pyrrolidine derivatives; the good solvent is toluene, m-xylene, mesitylene, or carbon disulfide; the poor solvent is isopropanol, n-butanol, tert-butanol, or n-heptanol.

6. The method for preparing intrinsically defect-rich carbon materials according to claim 1, characterized in that, The preparation method of the fullerene-based condensed state precursor is as follows: dissolve fullerene or fullerene derivative in a good solvent to obtain a fullerene solution, add a poor solvent to the fullerene solution, and form an interface between the good solvent and the poor solvent to obtain a boundary solution. Allow the boundary solution to stand at room temperature for spontaneous growth to obtain the fullerene-based condensed state precursor.

7. The method for preparing intrinsically defect-rich carbon materials according to claim 1, characterized in that, The programmed calcination after holding at 280°C to 300°C specifically involves calcining at a rate of 5°C / min from room temperature to 600°C to 800°C for 1 to 2 hours.

8. A carbon material rich in intrinsic defects, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the intrinsically defect-rich carbon material of claim 8 in the catalytic oxygen reduction reaction.

10. The application of the intrinsically defect-rich carbon material of claim 8 in a zinc-air battery.

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