Preparation method of nitrogen-oxygen co-doped nanoporous carbon material and application thereof

Abstract

The present application relates to a kind of preparation method of nitrogen-oxygen co-doped nanoporous carbon material and its application, with the following steps: resorcinol, polyaspartic acid potassium, polyvinyl alcohol, 4-dimethylaminopyridine are dissolved in distilled water stirring 10~60 minutes, then add sepiolite powder, ultrasonic oscillation at room temperature 30~60 minutes, finally add formaldehyde aqueous solution, seal, continue ultrasonic oscillation 1~3 hours, obtain gel product;The gel product obtained is dried to obtain intermediate;The intermediate obtained is carbonized to obtain black product;The black product obtained is pickled and washed with water, dried to obtain nitrogen-oxygen co-doped nanoporous carbon material.The porous carbon material obtained by the present application has large specific surface area and strong adsorption capacity, and the preparation method has high reaction yield.

Description

Technical Field

[0001] This invention belongs to the field of carbon materials technology, and relates to a method for preparing nitrogen-oxygen co-doped nanoporous carbon materials and their applications. Background Technology

[0002] Currently, research on carbon dioxide capture technology is receiving significant attention to address the severe environmental and climate impacts of large amounts of carbon dioxide. A key aspect of carbon dioxide capture technology is the development of adsorbents with excellent adsorption performance. In recent years, porous materials such as activated carbon, zeolite molecular sieves, and metal-organic frameworks have been studied and applied to carbon dioxide adsorption. Porous carbon materials, due to their large specific surface area and pore volume, are advantageous for the physical adsorption of CO2. Chemical modification of the surface of porous carbon materials, adding active sites suitable for CO2 adsorption, can enhance their chemical adsorption capacity. Literature reports that the introduction of nitrogen-containing groups such as amines can alter the surface chemical properties of porous carbon and enhance its CO2 adsorption capacity.

[0003] The inventors have conducted a series of studies on carbon dioxide adsorption and the development of nitrogen-containing porous carbon materials. For example, CN201710364105.9 describes a microporous carbon aerogel with high specific surface area, narrow pore size distribution, large pore volume, and strong carbon dioxide adsorption capacity obtained by adding a mixed eutectic salt composed of LiNO3, KNO3, and K2SO4 in a single step during the preparation of an organic wet gel. CN201911004675.2 relates to a method for preparing nitrogen-containing porous carbon materials based on polyaspartic acid salt and its application. The polyaspartic acid salt is carbonized in a carbonization furnace under vacuum to obtain a black nitrogen-containing carbon material. After acid washing, the nitrogen-containing porous carbon material is obtained. The method provided in this invention yields a nitrogen-containing porous carbon material with a large specific surface area and a more uniform distribution of nitrogen atoms and pore size. These methods provide a reference for preparing carbon materials with large specific surface area, large pore volume, concentrated pore size distribution, strong adsorption capacity, and uniform nitrogen atom distribution.

[0004] However, the above-mentioned methods have problems such as low yield. In order to promote the practical application of porous carbon materials for carbon dioxide adsorption, it is of great significance to provide an efficient preparation method for porous carbon materials with large specific surface area, large pore volume, concentrated pore size distribution, uniform pore distribution and strong adsorption capacity. Summary of the Invention

[0005] The technical problem to be solved by the present invention is a method for preparing nitrogen-oxygen co-doped nanoporous carbon materials, which has good yield and good performance products.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] The first aspect of this invention provides a method for preparing nitrogen-oxygen co-doped nanoporous carbon materials, comprising the following steps:

[0008] S1: Dissolve resorcinol, potassium polyaspartate, polyvinyl alcohol, and 4-dimethylaminopyridine in distilled water and stir for 10-60 minutes. Then add sepiolite powder and sonicate at room temperature for 30-60 minutes. Finally, add formaldehyde aqueous solution, seal, and continue sonicating for 1-3 hours to obtain the gel product.

[0009] S2: The obtained gel product is dried to obtain an intermediate;

[0010] S3: Carbonize the obtained intermediate to obtain a black product;

[0011] S4: The obtained black product was acid-washed and water-washed, and then dried to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0012] The mass ratio of resorcinol, polyaspartic acid, polyvinyl alcohol, 4-dimethylaminopyridine and sepiolite powder is 2.2~4.5: 2.4~4.4: 0.7~1.3: 0.8~1.3: 1.1~3.2.

[0013] As a further improvement of the present invention, the mass ratio of resorcinol, polyaspartic acid, polyvinyl alcohol, 4-dimethylaminopyridine and sepiolite powder in S1 is 3:3:1:1:2.

[0014] As a further improvement of the present invention, the mass of the distilled water in S1 is 40 to 60 times the total mass of resorcinol, polyaspartic acid, polyvinyl alcohol, 4-dimethylaminopyridine, sepiolite powder and formaldehyde aqueous solution.

[0015] As a further improvement of the present invention, the molar ratio of formaldehyde to resorcinol in S1 is 2.5~3:2, and the mass fraction of the formaldehyde aqueous solution is 35~40%.

[0016] As a further improvement of the present invention, the drying process in S2 is as follows: the gel product obtained in S1 is placed in a freeze-drying oven and freeze-dried at -60~-100℃ for 36~72 hours.

[0017] As a further improvement of the present invention, the carbonization process described in S3 is as follows: the product after freeze-drying in S2 is placed in a muffle furnace under a protective atmosphere, and heated from room temperature to 300-700°C at a heating rate of 2-4°C / min, held at that temperature for 0.5-1.5 hours, and then heated to 800-1000°C at a heating rate of 5-8°C / min, held at that temperature for 1-3 hours, and then cooled to 300-700°C at a rate of 3-8°C / min, and then allowed to cool naturally to room temperature.

[0018] As a further improvement of the present invention, the protective gas is nitrogen or argon, and the protective gas introduction rate is 20~30 mL / min.

[0019] As a further improvement of the present invention, the acid washing and water washing treatment in S4 is as follows: the black product obtained in S3 is placed in an HF aqueous solution and stirred for 6 to 18 hours, then filtered and washed 3 times with distilled water.

[0020] As a further improvement of the present invention, the concentration of the HF aqueous solution is 0.5~1.5M, and the volume ratio of the HF aqueous solution to the mass ratio of the black product obtained by adding S3 is 80~120mL:1g.

[0021] A second aspect of the present invention provides an application of the nitrogen-oxygen co-doped nanoporous carbon material obtained by the preparation method described above in the field of carbon dioxide adsorption.

[0022] The beneficial effects of adopting the above technical solution are as follows:

[0023] 1. The addition of sepiolite powder, polyethylene, and 4-dimethylaminopyridine creates a synergistic effect that promotes the reaction of raw materials and increases the product yield.

[0024] 2. The addition of potassium polyaspartate and sepiolite powder controls the size, morphology and structure of nanomaterials.

[0025] 3. The preparation method of the present invention has a high yield, and the obtained product has a large surface area and good carbon dioxide adsorption performance. Attached Figure Description

[0026] Figure 1 This is a nitrogen adsorption-desorption curve of the nitrogen-oxygen co-doped nanoporous carbon material obtained in Example 1 of the present invention;

[0027] Figure 2 This is a graph showing the pore size analysis results of the nitrogen-oxygen co-doped nanoporous carbon material obtained in Example 1 of the present invention;

[0028] Figure 3 This is a graph showing the carbon dioxide adsorption-desorption experimental results of the nitrogen-oxygen co-doped nanoporous carbon material obtained in Example 1 of this invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the invention will be described clearly and completely below in conjunction with specific embodiments.

[0030] Example 1

[0031] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 660mL of distilled water and stir for 30 minutes. Then add 2g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0032] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0033] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0034] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0035] Example 2

[0036] S1: Dissolve 2.2g resorcinol, 2.4g potassium polyaspartate, 0.7g polyvinyl alcohol, and 0.8g 4-dimethylaminopyridine in 575mL of distilled water and stir for 10 minutes. Then add 1.1g sepiolite powder and sonicate at room temperature for 30 minutes. Finally, add 2.2mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 1 hour to obtain the gel product.

[0037] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0038] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0039] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0040] Example 3

[0041] S1: Dissolve 4.5g resorcinol, 4.4g potassium polyaspartate, 1.3g polyvinyl alcohol, and 1.3g 4-dimethylaminopyridine in 770mL of distilled water and stir for 60 minutes. Then add 3.2g sepiolite powder and sonicate at room temperature for 60 minutes. Finally, add 4.5mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 3 hours to obtain the gel product.

[0042] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0043] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0044] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0045] Example 4

[0046] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 660mL of distilled water and stir for 30 minutes. Then add 2g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0047] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -60°C for 72 hours to obtain the intermediate;

[0048] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0049] S4: Weigh 5g of the black product obtained from S3, place it in 600mL of 0.5M HF aqueous solution, stir for 18 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0050] Example 5

[0051] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 660mL of distilled water and stir for 30 minutes. Then add 2g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0052] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -100℃ for 36 hours to obtain the intermediate;

[0053] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0054] S4: Weigh 5g of the black product obtained from S3, place it in 400mL of 1.5M HF aqueous solution, stir for 6 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0055] Example 6

[0056] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 660mL of distilled water and stir for 30 minutes. Then add 2g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0057] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0058] S3: The freeze-dried product of S2 was placed in a muffle furnace with argon gas introduced at a rate of 20 mL / min. The temperature was increased from room temperature to 300°C at a rate of 2°C / min and held for 1.5 hours. The temperature was then increased to 800°C at a rate of 5°C / min and held for 3 hours. The temperature was then decreased to 300°C at a rate of 3°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0059] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0060] Example 7

[0061] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 660mL of distilled water and stir for 30 minutes. Then add 2g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0062] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0063] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 30 mL / min. The temperature was increased from room temperature to 700°C at a rate of 4°C / min and held for 0.5 hours. The temperature was then increased to 1000°C at a rate of 8°C / min and held for 1 hour. The temperature was then decreased to 700°C at a rate of 8°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0064] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0065] Comparative Example 1

[0066] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, and 1g 4-dimethylaminopyridine in 615mL of distilled water and stir for 30 minutes. Then add 2g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0067] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0068] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0069] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0070] Comparative Example 2

[0071] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate and 1g polyvinyl alcohol in 615mL distilled water and stir for 30 minutes. Then add 2g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal and continue sonicating for 2 hours to obtain the gel product.

[0072] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0073] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0074] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0075] Comparative Example 3

[0076] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 565mL of distilled water and stir for 30 minutes. Add 3mL of 37% formaldehyde aqueous solution, seal, and continue ultrasonic vibration for 2 hours to obtain the gel product.

[0077] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0078] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0079] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0080] Comparative Example 4

[0081] S1: Add 3g of resorcinol to 3mL of 37% formaldehyde aqueous solution and stir for 30 minutes. Then add 3g of potassium polyaspartate, 1g of polyvinyl alcohol, and 1g of 4-dimethylaminopyridine dissolved in 660mL of distilled water and stir for 30 minutes. Then add 2g of sepiolite powder and sonicate at room temperature for 40 minutes. Finally, seal and continue to sonicate for 2 hours to obtain the gel product.

[0082] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0083] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0084] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0085] Comparative Example 5

[0086] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 660mL of distilled water, then add 2g sepiolite powder, sonicate at room temperature for 40 minutes, and finally add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0087] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0088] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0089] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0090] Comparative Example 6

[0091] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 660mL of distilled water and stir for 30 minutes. Then add 2g sepiolite powder and finally add 3mL of 37% formaldehyde aqueous solution. Seal and continue to sonicate for 2 hours to obtain the gel product.

[0092] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0093] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0094] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0095] Comparative Example 7

[0096] S1: Dissolve 3g resorcinol, 3g potassium carbonate, 3g 4-(dimethylamino)benzyl alcohol, 1g polyvinyl alcohol, and 1g 4-dimethylaminopyridine in 810mL of distilled water and stir for 30 minutes. Then add 2g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0097] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0098] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0099] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0100] Comparative Example 8

[0101] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 0.5g polyvinyl alcohol, and 0.5g 4-dimethylaminopyridine in 565mL of distilled water and stir for 30 minutes. Then add 1g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0102] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0103] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0104] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0105] Comparative Example 9

[0106] S1: Dissolve 3g resorcinol, 3g potassium polyaspartate, 2g polyvinyl alcohol, and 2g 4-dimethylaminopyridine in 865mL of distilled water and stir for 30 minutes. Then add 4g sepiolite powder and sonicate at room temperature for 40 minutes. Finally, add 3mL of 37% formaldehyde aqueous solution, seal, and continue sonicating for 2 hours to obtain the gel product.

[0107] S2: The gel product obtained in S1 was placed in a freeze dryer and freeze-dried at -85°C for 48 hours to obtain the intermediate;

[0108] S3: The freeze-dried product of S2 was placed in a muffle furnace with nitrogen flowing through it at a rate of 25 mL / min. The temperature was increased from room temperature to 500°C at a rate of 3°C / min and held for 1 hour. The temperature was then increased to 900°C at a rate of 5°C / min and held for 2 hours. The temperature was then decreased to 500°C at a rate of 5°C / min and then allowed to cool naturally to room temperature to obtain a black product.

[0109] S4: Weigh 5g of the black product obtained from S3, place it in 500mL of 1M HF aqueous solution, stir for 12 hours, filter, wash 3 times with distilled water, and dry to obtain nitrogen-oxygen co-doped nanoporous carbon material.

[0110] Table 1 Yields of Examples 1-7 and Comparative Examples 1-9

[0111]

[0112] Test Example 1

[0113] (a) A nitrogen adsorption-desorption experiment was conducted on the material prepared in Example 1, and the results are as follows: Figure 1 As shown.

[0114] (b) Pore size analysis was performed on the material prepared in Example 1, and the results are as follows: Figure 2 As shown.

[0115] (c) The carbon dioxide adsorption test was performed on the material prepared in Example 1, and the results are as follows: Figure 3 As shown.

[0116] Example 1

[0117] (a) Nitrogen adsorption-desorption experiments were conducted on the materials prepared in Examples 1-7 and Comparative Examples 1-9, and the specific surface area and pore size of the carbon materials were obtained as shown in Table 2.

[0118] Table 2. Results of nitrogen adsorption-desorption experiments in Examples 1-7 and Comparative Examples 1-9

[0119]

[0120] (b) Carbon dioxide adsorption experiment

[0121] The porous carbon materials prepared in Examples 1-7 and Comparative Examples 1-9 were subjected to carbon dioxide adsorption experiments using volumetric methods at 0℃. The experimental results are shown in Table 3.

[0122] Table 3 Carbon dioxide adsorption capacity at a pressure of 1 bar

[0123]

[0124] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing nitrogen-oxygen co-doped nanoporous carbon materials, characterized in that, It includes the following steps: S1: Dissolve resorcinol, potassium polyaspartate, polyvinyl alcohol, and 4-dimethylaminopyridine in distilled water and stir for 10-60 minutes. Then add sepiolite powder and sonicate at room temperature for 30-60 minutes. Finally, add formaldehyde aqueous solution, seal, and continue sonicating for 1-3 hours to obtain the gel product. S2: The obtained gel product is dried to obtain an intermediate; S3: Carbonize the obtained intermediate to obtain a black product; S4: The obtained black product is acid-washed and water-washed, and then dried to obtain nitrogen-oxygen co-doped nanoporous carbon material. The mass ratio of resorcinol, polyaspartic acid, polyvinyl alcohol, 4-dimethylaminopyridine and sepiolite powder is 2.2~4.5: 2.4~4.4: 0.7~1.3: 0.8~1.3: 1.1~3.

2.

2. The method for preparing a nitrogen-oxygen co-doped nanoporous carbon material according to claim 1, characterized in that, The mass ratio of resorcinol, polyaspartic acid, polyvinyl alcohol, 4-dimethylaminopyridine, and sepiolite powder in S1 is 3:3:1:1:

2.

3. The method for preparing a nitrogen-oxygen co-doped nanoporous carbon material according to claim 1, characterized in that, The mass of the distilled water in S1 is 40 to 60 times the total mass of resorcinol, polyaspartic acid, polyvinyl alcohol, 4-dimethylaminopyridine, sepiolite powder, and formaldehyde aqueous solution.

4. The method for preparing a nitrogen-oxygen co-doped nanoporous carbon material according to claim 1, characterized in that, The molar ratio of formaldehyde to resorcinol in S1 is 2.5~3:2, and the mass fraction of the formaldehyde aqueous solution is 35~40%.

5. The method for preparing a nitrogen-oxygen co-doped nanoporous carbon material according to claim 1, characterized in that, The drying process described in S2 is as follows: the gel product obtained in S1 is placed in a freeze-drying oven and freeze-dried at -60~-100℃ for 36~72 hours.

6. The method for preparing a nitrogen-oxygen co-doped nanoporous carbon material according to claim 1, characterized in that, The carbonization process described in S3 is as follows: the product after freeze-drying in S2 is placed in a muffle furnace under a protective atmosphere, heated from room temperature to 300-700°C at a heating rate of 2-4°C / min, held at that temperature for 0.5-1.5 hours, then heated to 800-1000°C at a heating rate of 5-8°C / min, held at that temperature for 1-3 hours, then cooled to 300-700°C at a heating rate of 3-8°C / min, and then allowed to cool naturally to room temperature.

7. The method for preparing a nitrogen-oxygen co-doped nanoporous carbon material according to claim 6, characterized in that, The protective gas is nitrogen or argon, and the protective gas introduction rate is 20~30 mL / min.

8. The method for preparing a nitrogen-oxygen co-doped nanoporous carbon material according to claim 1, characterized in that, The acid washing and water washing treatment described in S4 is as follows: the black product obtained in S3 is placed in an HF aqueous solution and stirred for 6 to 18 hours, then filtered and washed 3 times with distilled water.

9. The method for preparing a nitrogen-oxygen co-doped nanoporous carbon material according to claim 8, characterized in that, The concentration of the HF aqueous solution is 0.5~1.5M, and the volume ratio of the HF aqueous solution to the mass ratio of the black product obtained by adding S3 is 80~120mL:1g.

10. The application of a nitrogen-oxygen co-doped nanoporous carbon material obtained by the preparation method according to any one of claims 1 to 9 in the field of carbon dioxide adsorption.

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