Preparation process of nano carbon material
By optimizing the electrolyte and electrode materials, and combining pulsed voltage electrolysis with simple post-processing, the problems of low efficiency, high energy consumption, and environmental pollution in the preparation of nano-carbon sols have been solved, realizing the preparation of high-efficiency, low-energy-consumption nano-carbon materials suitable for various application scenarios.
Patent Information
- Application Number
- CN202511255025.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-04
- Publication Date
- 2025-11-14
AI Technical Summary
Existing nano-carbon sol preparation processes suffer from problems such as low reaction efficiency, high energy consumption, poor equipment stability, high raw material costs, severe product agglomeration, and high environmental pollution risks, making it difficult to meet the needs of the food and pharmaceutical industries.
An electrolyte prepared with ionic liquid and organic precursors is combined with graphite felt and platinum sheet or stainless steel mesh electrodes to generate nano-carbon particles through pulsed voltage electrolysis. The particles are then separated by centrifugation and subjected to simple post-processing. Electrolysis conditions are controlled to suppress agglomeration and reduce energy consumption.
It significantly improves the production efficiency and purity of nano-carbon materials, reduces energy consumption, simplifies the post-processing, adapts to particle size control in different application scenarios, and reduces the risk of environmental pollution.
Smart Images
Figure CN120945384A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical technology, and more specifically to the preparation process of nano-carbon materials. Background Technology
[0002] Currently, the preparation of nano-carbon sols mainly relies on electrochemical methods. The core principle is to dissociate carbon sources (such as graphite electrodes) into nano-sized carbon particles in an electrolyte through an electrolysis process.
[0003] Specific technical means include: 1. Electrolyte preparation: Commonly used are ionic liquids and neutral electrolyte aqueous solutions (such as those containing sodium chloride, vanadium pentoxide, etc.). Some processes add surfactants to control dispersibility.
[0004] 2. Electrode material: Traditional processes often use high-purity graphite electrodes (purity ≥ 95%), and carbon ions are driven to leave the electrode by DC or pulse voltage.
[0005] 3. Reaction conditions: Voltage range is typically 11-110V, current density is 35-48A / m 2 The reaction time varies from 4 hours to 15 days, depending on the electrolyte composition and the particle size of the target product.
[0006] 4. Post-processing: The nano-carbon sol is separated and purified through steps such as centrifugation, washing, and drying. Some processes require ultrasonic dispersion to inhibit agglomeration.
[0007] The above-mentioned processing technology has the following defects: 1. Equipment and process defects Low reaction efficiency: Traditional electrolyzers lack precise feeding and mixing devices, resulting in low raw material utilization. Furthermore, the electrolyte resistance increases in the later stages of the reaction (reaching 120-150% of the initial value), current density decreases, and production cycle is prolonged.
[0008] High energy consumption: The reaction requires high temperature or high power supply, and some processes require additional cooling measures, resulting in high overall energy consumption.
[0009] Poor equipment stability: Existing devices lack buffer and shock absorption design, and long-term operation is prone to mechanical vibration, which affects the uniformity of nanoparticle size.
[0010] 2. Limitations of materials and products High raw material costs: It relies on high-purity graphite electrodes (costing approximately 140 yuan per set) and has poor biocompatibility, making it difficult to meet the needs of the food and pharmaceutical industries.
[0011] The product exhibits severe agglomeration: the high surface energy of nano-carbon particles makes them prone to irreversible agglomeration, requiring complex post-processing (such as acid leaching and freeze-drying), which increases costs.
[0012] Environmental risks: Some processes use strong acid and strong base electrolytes (such as pH < 2), which poses a pollution risk, and the pH value of the products fluctuates greatly, limiting their application in fields such as soil remediation.
[0013] 3. Insufficient control of process parameters Uncontrollable particle size: Traditional methods make it difficult to precisely control the size of carbon particles (usually 10-100nm), resulting in unstable product performance.
[0014] The reaction conditions are stringent: parameters such as voltage and temperature must be strictly controlled, otherwise side reactions (such as hydrogen evolution and oxygen evolution) may easily occur, reducing the purity of the product. Summary of the Invention
[0015] The purpose of this invention is to address the aforementioned problems in existing technologies by providing a preparation process for nano-carbon materials that has a short preparation cycle and low energy consumption.
[0016] To achieve the above objectives, the present invention can be implemented through the following technical solutions: A process for preparing nano-carbon materials, characterized by comprising the following steps: A. Electrolyte preparation: Ionic liquids and organic precursors are prepared, wherein the ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), accounts for 20-30 vol%, providing high conductivity and chemical stability; Organic precursor: polymaleic acid (3-8 g / L), as a carbon source; Deionized water: the remainder, used to adjust the ionic strength of the electrolyte; Electrode installation: Function: The distance between the anode and cathode is fixed at 2-3cm to ensure a uniform electric field distribution.
[0017] The anode is composed of graphite felt (porosity 70-80%) with a specific surface area of 1000-1500 m². 2 / g, promotes carbon source dissociation; Cathode: Platinum sheet or stainless steel mesh, 0.1-0.3 mm thick, to reduce hydrogen evolution side reaction; C. Electrolysis reaction: The carbon source is placed in the prepared electrolyte, and a pulse voltage is applied. The carbon source is anoly oxidized and dissociated into nano-sized carbon particles. D. Post-processing: The nanoscale carbon particles obtained after step C are centrifuged at 8000-10000 rpm for 10 minutes, and the precipitate is collected. The collected precipitate was washed alternately with ethanol and deionized water 2-5 times to remove residual electrolyte, and then dried to obtain the finished high-purity nano-carbon material.
[0018] In the above-mentioned preparation process of nano-carbon materials, the electrolyte formulation in step A has a specific ratio of ionic liquid to organic precursor (20-30 vol% BMIMBF4, 3-8 g / L polymaleic acid).
[0019] In the above-mentioned preparation process of nano-carbon materials, in step A, ionic liquid, organic precursor and deionized water are mixed and ultrasonically dispersed for 10 minutes to obtain the electrolyte of the finished homogeneous solution.
[0020] In the above-mentioned preparation process of nano-carbon materials, the porosity of the graphite felt anode in step B is 70-80%, and the specific surface area is 1000-1500 m². 2 / g).
[0021] In the above-mentioned preparation process of nano-carbon materials, the pulse voltage mode (accounting for 50%, frequency 100 Hz) in step C is used to suppress agglomeration.
[0022] In the above-mentioned preparation process of nano-carbon materials, the pulse voltage in step C is a direct current of 2.5-10.0 V.
[0023] In the above-described preparation process of carbon nanomaterials, the current density in step C is 0.1-0.5 A / cm². 2 .
[0024] In the above-mentioned preparation process of nano-carbon materials, the processing time of step C is 3-6 days.
[0025] In the above-mentioned preparation process of nano-carbon materials, in step D, the precipitate is dried in a vacuum environment at 60°C for 22-26 hours.
[0026] Compared with existing technologies, the preparation process of this nano-carbon material has the following advantages: 1. High efficiency: The single-batch yield is 3 times higher than that of traditional methods, significantly shortening the production cycle; 2. Low energy consumption: The combination of room temperature reaction and pulse technology reduces unit energy consumption by 80%; 3. Controllability: The carbon particle size (5-50 nm) can be adjusted by voltage parameters to adapt to different application scenarios; 4. Environmentally friendly: Water-based electrolyte reduces the use of organic solvents, and post-treatment is simple with no harmful residues. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the three-dimensional exploded structure of an electrolytic cell.
[0028] Figure 2 This is a cross-sectional view of the electrolytic cell.
[0029] In the diagram, 1 is the tank; 1a is the retaining edge; 2 is the positioning plate; 2a is the positioning groove; 3 is the cover plate one; 3a is the positioning hole; 4 is the cover plate two; and 5 is the carbon plate. Detailed Implementation
[0030] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention.
[0031] Example 1 The preparation process of this nano-carbon material includes the following steps: A. Electrolyte preparation: Ionic liquid and organic precursor are prepared, wherein the ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), accounting for 20 vol%, which provides high conductivity and chemical stability; Organic precursor: polymaleic acid (3 g / L), as a carbon source; Deionized water: the remainder, used to adjust the ionic strength of the electrolyte; The surfactant in the prepared electrolyte is adsorbed onto the surface of carbon nanoparticles, effectively reducing surface energy and inhibiting aggregation.
[0032] B. Electrode installation: Function: The distance between the anode and cathode is fixed at 2cm to ensure a uniform electric field distribution.
[0033] The anode is composed of graphite felt (70% porosity) with a specific surface area of 1000 m². 2 / g, promotes carbon source dissociation; Cathode: Platinum sheet or stainless steel mesh, 0.1 mm thick, to reduce hydrogen evolution side reaction; In this step, porous graphite felt increases the reaction area and improves the utilization rate of carbon source.
[0034] C. Electrolysis reaction: The carbon source is placed in the prepared electrolyte, and a pulse voltage is applied. The carbon source is anoly oxidized and dissociated into nano-sized carbon particles. In this step, due to the application of a pulse voltage, the carbon source is stably oxidized and dissociated into nanoscale carbon particles at the anode.
[0035] The carbon particle size (5 nm) can be controlled by voltage, and the pulse mode can effectively reduce the formation of byproducts.
[0036] D. Post-processing: The nanoscale carbon particles obtained after step C were centrifuged at 8000 rpm for 10 minutes, and the precipitate was collected. The collected precipitate was washed twice alternately with ethanol and deionized water to remove residual electrolyte, and then dried to obtain the high-purity nano-carbon material.
[0037] The electrolyte formulation in step A has a specific ratio of ionic liquid to organic precursor (20 vol% BMIMBF4, 3 g / L polymaleic acid).
[0038] In step A, the ionic liquid, organic precursor, and deionized water are mixed and ultrasonically dispersed for 10 minutes to obtain the electrolyte of the homogeneous solution.
[0039] In step B, the porosity (70%) and specific surface area (1000 m²) of the graphite felt anode are... 2 / g).
[0040] In step C, the pulse voltage mode (50% of the total, 100 Hz) is used to suppress aggregation.
[0041] In step C, the pulse voltage is a 2.5 V DC current.
[0042] The current density in step C is 0.1 A / cm². 2 .
[0043] The processing time for step C is 3 days.
[0044] In step D, the precipitate is dried in a vacuum environment at 60°C for 22 hours.
[0045] The material parameters in this embodiment are as follows: 1. Material Characterization TEM analysis: The average particle size of the carbon quantum dots is 10 nm.
[0046] XPS test: The surface contains functional groups such as hydroxyl (-OH) and carboxyl (-COOH).
[0047] 2. Comparative Experiment Yield: The yield of traditional CVD method is <10%, while the yield of this process is 30% per cycle.
[0048] Energy consumption: Energy consumption per unit mass of product is reduced by 80%, and costs are reduced by 60%.
[0049] Example 2 The preparation process of this nano-carbon material includes the following steps: A. Electrolyte preparation: Ionic liquid and organic precursor are prepared, wherein the ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), accounting for 30 vol%, which provides high conductivity and chemical stability; Organic precursor: polymaleic acid (8 g / L), as a carbon source; Deionized water: the remainder, used to adjust the ionic strength of the electrolyte; The surfactant in the prepared electrolyte is adsorbed onto the surface of carbon nanoparticles, effectively reducing surface energy and inhibiting aggregation.
[0050] B. Electrode installation: Function: The distance between the anode and cathode is fixed at 3cm to ensure a uniform electric field distribution.
[0051] The anode is composed of graphite felt (porosity 80%) with a specific surface area of 1500 m². 2 / g, promotes carbon source dissociation; Cathode: Platinum sheet or stainless steel mesh, 0.3 mm thick, to reduce hydrogen evolution side reaction; In this step, porous graphite felt increases the reaction area and improves the utilization rate of carbon source.
[0052] C. Electrolysis reaction: The carbon source is placed in the prepared electrolyte, and a pulse voltage is applied. The carbon source is anoly oxidized and dissociated into nano-sized carbon particles. In this step, due to the application of a pulse voltage, the carbon source is stably oxidized and dissociated into nanoscale carbon particles at the anode.
[0053] The carbon particle size (50 nm) can be controlled by voltage, and the pulse mode can effectively reduce the formation of byproducts.
[0054] D. Post-processing: The nanoscale carbon particles obtained after step C were centrifuged at 0000 rpm for 10 minutes, and the precipitate was collected. The collected precipitate was washed five times alternately with ethanol and deionized water to remove residual electrolyte, and then dried to obtain the finished high-purity nano-carbon material.
[0055] The electrolyte formulation in step A has a specific ratio of ionic liquid to organic precursor (30 vol% BMIMBF4, 8 g / L polymaleic acid).
[0056] In step A, the ionic liquid, organic precursor, and deionized water are mixed and ultrasonically dispersed for 10 minutes to obtain the electrolyte of the homogeneous solution.
[0057] In step B, the porosity (80%) and specific surface area (1500 m²) of the graphite felt anode are...2 / g).
[0058] In step C, the pulse voltage mode (50% of the total, 100 Hz) is used to suppress aggregation.
[0059] In step C, the pulse voltage is a 10.0 V DC current.
[0060] The current density in step C is 0.5 A / cm². 2 .
[0061] The processing time for step C is 6 days.
[0062] In step D, the precipitate is dried in a vacuum environment at 60°C for 26 hours.
[0063] The material parameters in this embodiment are as follows: 1. Material Characterization TEM analysis: The average particle size of the carbon quantum dots is 50 nm.
[0064] XPS test: The surface contains functional groups such as hydroxyl (-OH) and carboxyl (-COOH).
[0065] 2. Comparative Experiment Yield: The yield of traditional CVD method is <10%, while the yield of this process is 40% per cycle.
[0066] Energy consumption: Energy consumption per unit mass of product is reduced by 80%, and costs are reduced by 60%.
[0067] Example 3 The preparation process of this nano-carbon material includes the following steps: A. Electrolyte preparation: Ionic liquid and organic precursor are prepared, wherein the ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), accounting for 22 vol%, which provides high conductivity and chemical stability; Organic precursor: polymaleic acid (4 g / L), as a carbon source; Deionized water: the remainder, used to adjust the ionic strength of the electrolyte; The surfactant in the prepared electrolyte is adsorbed onto the surface of carbon nanoparticles, effectively reducing surface energy and inhibiting aggregation.
[0068] B. Electrode installation: Function: The distance between the anode and cathode is fixed at 2cm to ensure a uniform electric field distribution.
[0069] The anode is composed of graphite felt (porosity 73%) with a specific surface area of 1400 m². 2 / g, promotes carbon source dissociation; Cathode: Platinum sheet or stainless steel mesh, 0.2 mm thick, to reduce hydrogen evolution side reaction; In this step, porous graphite felt increases the reaction area and improves the utilization rate of carbon source.
[0070] C. Electrolysis reaction: The carbon source is placed in the prepared electrolyte, and a pulse voltage is applied. The carbon source is anoly oxidized and dissociated into nano-sized carbon particles. In this step, due to the application of a pulse voltage, the carbon source is stably oxidized and dissociated into nanoscale carbon particles at the anode.
[0071] The carbon particle size (32 nm) can be controlled by voltage, and the pulse mode can effectively reduce the formation of byproducts.
[0072] D. Post-processing: The nanoscale carbon particles obtained after step C were centrifuged at 8950 rpm for 10 minutes, and the precipitate was collected. The collected precipitate was washed three times alternately with ethanol and deionized water to remove residual electrolyte, and then dried to obtain the finished high-purity nano-carbon material.
[0073] The electrolyte formulation in step A has a specific ratio of ionic liquid to organic precursor (22 vol% BMIMBF4, 4 g / L polymaleic acid).
[0074] In step A, the ionic liquid, organic precursor, and deionized water are mixed and ultrasonically dispersed for 10 minutes to obtain the electrolyte of the homogeneous solution.
[0075] In step B, the porosity (72%) and specific surface area (1300 m²) of the graphite felt anode are... 2 / g).
[0076] In step C, the pulse voltage mode (50% of the total, 100 Hz) is used to suppress aggregation.
[0077] In step C, the pulse voltage is a 5V DC voltage.
[0078] The current density in step C is 0.3 A / cm². 2 .
[0079] The processing time for step C is 4 days.
[0080] In step D, the precipitate is dried in a vacuum environment at 60°C for 24 hours.
[0081] The material parameters in this embodiment are as follows: 1. Material Characterization TEM analysis: The average particle size of the carbon quantum dots is 30 nm.
[0082] XPS test: The surface contains functional groups such as hydroxyl (-OH) and carboxyl (-COOH).
[0083] 2. Comparative Experiment Yield: The yield of traditional CVD method is <10%, while the yield of this process is 33% per cycle.
[0084] Energy consumption: Energy consumption per unit mass of product is reduced by 80%, and costs are reduced by 60%.
[0085] like Figure 1 and Figure 2 As shown, this electrolytic cell includes a tank body 1, a positioning plate 2, a first cover plate 3, a second cover plate 4, and a carbon plate 5. The positioning plate 2 is fixedly connected to the tank body 1 and has a recessed positioning groove 2a on its upper part. The first cover plate 3 has a through positioning hole 3a. The lower part of the carbon plate 5 is embedded in the positioning groove 2a, and the upper part of the carbon plate 5 is embedded in the positioning hole 3a. The end of the tank body 1 has a protruding retaining edge 1a. The first cover plate 3 and the second cover plate 4 can both abut against the retaining edge 1a, and the first cover plate 3 is pressed tightly between the second cover plate 4 and the upper part of the tank body 1. The tank 1 is made of corrosion-resistant material.
[0086] The electrolytic cell is made of corrosion-resistant material to ensure it is not corroded by the electrolyte during electrolysis. The positioning plate design allows for stable installation of the carbon plates, ensuring uniform electrolytic reaction. The two cover plates not only facilitate operation but also effectively prevent electrolyte splashing, improving experimental safety. Furthermore, the electrolytic cell design considers heat dissipation performance, ensuring that the cell temperature does not become excessively high during prolonged electrolysis, thus affecting the electrolysis effect. By combining this electrolytic cell with the aforementioned preparation process, high-purity nano-carbon materials can be prepared efficiently and stably.
[0087] The technical solutions of the present invention described above provide solutions that are significantly different from those of the prior art, addressing the problem that existing technical solutions are too simplistic. The parts not covered in this application are the same as or can be implemented using existing technologies, and will not be described in detail here.
[0088] The technical solutions in the above embodiments have clearly and completely described the content of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
Claims
1. A preparation process for nano-carbon materials, characterized in that, This process includes the following steps: A. Electrolyte preparation: Ionic liquids and organic precursors are prepared, wherein the ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), accounts for 20-30 vol%, providing high conductivity and chemical stability; Organic precursor: polymaleic acid (3-8 g / L), as a carbon source; Deionized water: the remainder, used to adjust the ionic strength of the electrolyte; B. Electrode installation: Function: The distance between the anode and cathode is fixed at 2-3 cm to ensure a uniform electric field distribution. Anode: graphite felt (porosity 70-80%), specific surface area 1000-1500 m² / g, promotes carbon source dissociation; Cathode: platinum sheet or stainless steel mesh, thickness 0.1-0.3 mm, reduces hydrogen evolution side reactions. C. Electrolysis reaction: The carbon source is placed in the prepared electrolyte, and a pulse voltage is applied. The carbon source is anoly oxidized and dissociated into nano-sized carbon particles. D. Post-processing: The nanoscale carbon particles obtained after step C were centrifuged at 8000-10000 rpm for 10 minutes, and the precipitate was collected. The collected precipitate was washed alternately with ethanol and deionized water 2-5 times to remove residual electrolyte, and then dried to obtain the finished high-purity nano-carbon material.
2. The preparation process of nano-carbon materials according to claim 1, characterized in that, The electrolyte formulation in step A has a specific ratio of ionic liquid to organic precursor (20-30 vol% BMIMBF4, 3-8 g / L polymaleic acid).
3. The preparation process of nano-carbon materials according to claim 2, characterized in that, In step A, the ionic liquid, organic precursor, and deionized water are mixed and ultrasonically dispersed for 10 minutes to obtain the electrolyte of the homogeneous solution.
4. The preparation process of the nano-carbon material according to claim 3, characterized in that, The porosity (70-80%) and specific surface area (1000-1500 m² / g) of the graphite felt anode in step B.
5. The preparation process of nano-carbon materials according to claim 4, characterized in that, In step C, the pulse voltage mode (50% of the total, 100 Hz) is used to suppress aggregation.
6. The preparation process of nano-carbon materials according to claim 5, characterized in that, In step C, the pulse voltage is a direct current of 2.5-10.0 V.
7. The preparation process of nano-carbon materials according to claim 6, characterized in that, The current density in step C is 0.1-0.5 A / cm².
8. The preparation process of nano-carbon materials according to claim 7, characterized in that, The processing time for step C is 3-6 days.
9. The preparation process of nano-carbon materials according to claim 8, characterized in that, In step D, the precipitate is dried in a vacuum environment at 60°C for 22-26 hours.
10. The electrolytic cell used in the preparation process of nano-carbon materials according to any one of claims 1-9, characterized in that, The system includes a tank, a positioning plate, a first cover plate, a second cover plate, and a carbon plate. The positioning plate is fixed to the tank and has a recessed positioning groove on its upper part. The first cover plate has a through positioning hole. The lower part of the carbon plate is embedded in the positioning groove, and the upper part of the carbon plate is embedded in the positioning hole. The end of the tank has a protruding retaining edge. Both the first cover plate and the second cover plate can abut against the retaining edge, and the first cover plate is pressed tightly between the second cover plate and the upper part of the tank. The tank is made of corrosion-resistant material.