Application of nitrogen-containing porous carbon material
The preparation of nitrogen-containing porous carbon materials by carbonizing reactants such as p-phenylenediamine and cyanochloride at high temperatures, solving the problems of complex preparation process and waste liquids in the prior art, and achieving efficient heavy metal ion adsorption effect.
Patent Information
- Application Number
- CN202311708786.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-13
- Publication Date
- 2025-06-13
AI Technical Summary
The prior art When preparing nitrogen and oxygen co-doped porous carbon materials, the process is complicated and a large amount of waste liquid is generated when etching and removing nano-oxide templates, which increases production costs and environmentally friendly treatment costs.
Para-phenylenediamine and tripercyanochloride are used as reactants and triethylamine is an acid binding agent. The nucleophilic substitution reaction of amino groups to chlorine atoms is used to generate microporous polymers with triazine structure, and nitrogen-containing porous carbon materials are prepared by high-temperature carbonization for heavy metal ion adsorption.
The preparation process is simplified, the waste liquid generated by etching is avoided, the production and environmentally friendly treatment costs are reduced, and the adsorption of heavy metal ions is increased, which has good application value.
Smart Images
Figure CN120132802A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of heavy metal pollution control, and in particular to the application of a nitrogen-containing porous carbon material. Background Art
[0002] Porous carbon materials are materials with a pore structure formed by carbon, whose pores are interconnected or closed, low-priced, widely available, relatively simple preparation process, high specific surface area and porosity, and can be widely used in gas or liquid phase physical adsorption. In addition, carbon materials have good chemical stability, acid and alkali resistance, and high stability to oxidants. They are the most commonly used materials in the field of adsorption. The increase in the specific surface area of carbon materials can effectively improve their adsorption capacity for metal ions in the liquid phase. In addition, under the same or similar specific surface conditions, the doping of heteroatoms such as nitrogen and phosphorus helps the interaction between the material surface and metal ions, and helps to increase the adsorption amount of the material. There are usually two ways to introduce nitrogen atoms. One is to carbonize the material containing both carbon and nitrogen. During the carbonization process, the nitrogen atoms are retained or partially retained, thereby forming a nitrogen-doped porous carbon material. The other is to first prepare a porous carbon material, and then calcine it in an ammonia atmosphere, so that the nitrogen element is deposited in the carbon material or replaces part of the carbon material, thereby forming a nitrogen-doped porous carbon material.
[0003] With the development of the economy, people pay more and more attention to heavy metal pollution, and environmental protection emission standards are getting higher and higher. How to economically and efficiently remove heavy metal ions in industrial wastewater is an important problem that needs to be solved urgently. Among them, porous carbon materials, as a commonly used adsorption material, have the characteristics of low cost and good stability. The invention patent with patent application number 2019113029335 discloses a method for preparing nitrogen-oxygen co-doped porous carbon materials by calcining a mixture of oxygen-containing organic matter and nitrogen-containing organic matter, and obtains a doped carbon material containing 5-25% nitrogen and oxygen. The removal rate of nickel ions by this material can reach more than 99%. In this method, the inventor uses nano-oxide as a template, carbonizes the material, and then removes the nano-oxide template agent by chemical etching, thereby preparing nitrogen-doped porous carbon materials. The preparation process is relatively complicated. In addition, in the process of etching and removing nano-oxides, a large amount of waste liquid will be generated, which increases the production cost and environmental protection treatment cost. Summary of the invention
[0004] The purpose of the present invention is to provide an application of nitrogen-containing porous carbon material for heavy metal ion adsorption.
[0005] The object of the present invention can be achieved by the following technical solutions: An application of a nitrogen-containing porous carbon material, using p-phenylenediamine and cyanuric chloride as reactants and triethylamine as an acid-binding agent to generate a microporous polymer with a triazine structure, and then obtaining the nitrogen-containing porous carbon material through high-temperature carbonization, and using the nitrogen-containing porous carbon material for heavy metal ion adsorption.
[0006] Preferably, the heavy metal ion is a lead ion.
[0007] More preferably, the nitrogen-containing porous carbon material is added to a lead nitrate solution for oscillatory adsorption.
[0008] Even more preferably, the mass ratio of the nitrogen-containing porous carbon material to lead nitrate is 8 - 12:1.
[0009] Preferably, the mass ratio of the nitrogen-containing porous carbon material to lead nitrate is 10:1.
[0010] Preferably, the specific surface area of the nitrogen-containing porous carbon material is 700 - 1200 m 2 / g.
[0011] Preferably, the total pore volume of the nitrogen-containing porous carbon material is 0.5 - 0.6 cm 3 / g.
[0012] Preferably, the nitrogen content of the nitrogen-containing porous carbon material is 1 - 12 wt%.
[0013] Preferably, p-phenylenediamine and cyanuric chloride are respectively dissolved in a solvent to obtain a p-phenylenediamine solution and a cyanuric chloride solution, triethylamine is added to the p-phenylenediamine solution, and then the cyanuric chloride solution is added dropwise to the p-phenylenediamine solution for reaction.
[0014] More preferably, before adding the cyanuric chloride solution dropwise to the p-phenylenediamine solution, the cyanuric chloride solution and the p-phenylenediamine solution containing triethylamine are pre-cooled in an ice bath.
[0015] Even more preferably, after adding the cyanuric chloride solution dropwise to the p-phenylenediamine solution, the reaction is carried out at 0 °C for 1.5 - 2.5 h. After the reaction is completed, the reaction continues at room temperature for 20 - 30 h, and finally the temperature is raised to 50 - 70 °C, and the reaction is carried out for 20 - 30 h under the condition of reflux condensation.
[0016] Preferably, p-phenylenediamine and cyanuric chloride are in an equimolar ratio.
[0017] Preferably, the high-temperature carbonization temperature is 700 - 1000 °C and the time is 1.5 - 2.5 h.
[0018] Preferably, during the high-temperature carbonization process, the temperature is raised to the carbonization temperature at a heating rate of 2 °C / min in a protective atmosphere.
[0019] Preferably, tetrahydrofuran is used as the solvent in the process of preparing the microporous polymer with a triazine structure.
[0020] Preferably, in the process of preparing the microporous polymer with a triazine structure, a protective gas is continuously introduced. After the reaction is complete, the product is centrifugally washed with ethanol, hydrochloric acid and ultrapure water to remove impurities and excess reactants in the product, and finally dried to obtain a light brown powder, namely the microporous polymer with a triazine structure.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] 1. In the present invention, p-phenylenediamine and cyanuric chloride are used as reactants, and triethylamine is used as an acid-binding agent. A microporous polymer with a triazine structure is formed through a nucleophilic substitution reaction of an amino group with a chlorine atom, and then a polymer-based nitrogen-containing porous carbon material is prepared through high-temperature carbonization, which has good applications in the field of heavy metal ion adsorption.
[0023] 2. The present invention provides a porous nitrogen-doped carbon material, which has a high adsorption capacity for heavy metal ions and has good application value.
[0024] 3. The preparation process of the present invention is simple, without etching, avoiding the generation of a large amount of waste liquid, and reducing the production cost and environmental protection treatment cost. Description of the Drawings
[0025] Figure 1 is the SEM electron micrograph of Sample 1;
[0026] Figure 2 is the SEM electron micrograph of Sample 2;
[0027] Figure 3 is the SEM electron micrograph of Sample 3;
[0028] Figure 4 is the SEM electron micrograph of Sample 4;
[0029] Figure 5 is the nitrogen adsorption-desorption isotherm test chart of Samples 1 to 4. Detailed Embodiments
[0030] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manner and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.
[0031] Example 1
[0032] First, add 3.46 g of 32 mmol of p-phenylenediamine (PPD) into a 250 ml three-necked flat-bottom flask, and add 150 ml of tetrahydrofuran (THF) as a solvent. After ultrasonic dissolution and homogenization, add an appropriate amount of triethylamine. At the same time, dissolve 5.9 g of 32 mmol of cyanuric chloride (TCT) in 50 ml of THF. After both are completely dissolved, pre-cool in an ice bath for 30 min, then add the TCT solution dropwise to the PPD solution, and react at 0 °C for 2 h; after the reaction is completed, continue the reaction at room temperature for 24 h; finally, raise the temperature to 60 °C and react under reflux condensation for 24 h. Nitrogen is passed throughout the reaction as a protective gas. After the reaction is complete, centrifuge and wash the product three times each with ethanol, 2M HCl, and ultrapure water to remove impurities and excess reactants in the product. Finally, place it in a vacuum oven at 60 °C and dry overnight to obtain a light brown powder. Name the synthesized triazine-based microporous polymer N-CTF.
[0033] Take the triazine-based microporous polymer prepared above as a nitrogen-containing precursor, add 1 g of the product into a porcelain boat, and heat it to 700 °C at a heating rate of 2 ° / min in an N 2 atmosphere, hold for 2 h, cool naturally to room temperature, take out the porcelain boat to obtain a black carbide, and finally centrifuge and wash it three times each with ethanol and ultrapure water, then dry it in a vacuum oven at 60 °C and grind it. Name the obtained triazine-based nitrogen-doped carbon material Sample 1.
[0034] Example 2
[0035] First, add 3.46 g of 32 mmol of p-phenylenediamine (PPD) into a 250 ml three-necked flat-bottom flask, and add 150 ml of tetrahydrofuran (THF) as a solvent. After ultrasonic dissolution and homogenization, add an appropriate amount of triethylamine. At the same time, dissolve 5.9 g of 32 mmol of cyanuric chloride (TCT) in 50 ml of THF. After both are completely dissolved, pre-cool in an ice bath for 30 min, then add the TCT solution dropwise to the PPD solution, and react at 0 °C for 2 h; after the reaction is completed, continue the reaction at room temperature for 24 h; finally, raise the temperature to 60 °C and react under reflux condensation for 24 h. Nitrogen is passed throughout the reaction as a protective gas. After the reaction is complete, centrifuge and wash the product three times each with ethanol, 2M HCl, and ultrapure water to remove impurities and excess reactants in the product. Finally, place it in a vacuum oven at 60 °C and dry overnight to obtain a light brown powder. Name the synthesized triazine-based microporous polymer N-CTF.
[0036] Take the triazine-based microporous polymer prepared above as a nitrogen-containing precursor, add 1 g of the product into a porcelain boat, and heat it to 700 °C at a heating rate of 2 ° / min in an N 2It was heated to 800 °C at a heating rate of 2 °C / min in a nitrogen atmosphere, held for 2 h, naturally cooled to room temperature, the porcelain boat was taken out, and black carbide was obtained. Finally, it was centrifugally washed three times with ethanol and ultrapure water respectively, then dried in a vacuum oven at 60 °C and ground. The obtained triazine-based nitrogen-doped carbon material was named Sample 2.
[0037] Example 3
[0038] First, 32 mmol of p-phenylenediamine (PPD), 3.46 g, was added to a 250 ml flat-bottomed three-necked flask, and 150 ml of tetrahydrofuran (THF) was added as a solvent. After ultrasonic dissolution and homogenization, an appropriate amount of triethylamine was added. At the same time, 32 mmol of cyanuric chloride (TCT), 5.9 g, was dissolved in 50 ml of THF. After both were completely dissolved, they were pre-cooled in an ice bath for 30 min, then the TCT solution was added dropwise to the PPD solution, and the reaction was carried out at 0 °C for 2 h; after the reaction was completed, the reaction was continued at room temperature for 24 h; finally, the temperature was raised to 60 °C, and the reaction was carried out under reflux condensation for 24 h. Nitrogen was passed through the whole reaction as a protective gas. After the reaction was completed, the product was centrifugally washed three times with ethanol, 2M HCl and ultrapure water respectively to remove impurities and excess reactants in the product, and finally dried overnight in a vacuum oven at 60 °C to obtain a light brown powder. The synthesized triazine-based microporous polymer was named N-CTF.
[0039] Taking the above-prepared triazine-based microporous polymer as a nitrogen-containing precursor, 1 g of the product was added to a porcelain boat, and it was heated to 900 °C at a heating rate of 2 °C / min in a nitrogen 2 atmosphere, held for 2 h, naturally cooled to room temperature, the porcelain boat was taken out, and black carbide was obtained. Finally, it was centrifugally washed three times with ethanol and ultrapure water respectively, then dried in a vacuum oven at 60 °C and ground. The obtained triazine-based nitrogen-doped carbon material was named Sample 3.
[0040] Example 4
[0041] First, 32 mmol of p-phenylenediamine (PPD), 3.46 g, was added to a 250 ml flat-bottomed three-necked flask, and 150 ml of tetrahydrofuran (THF) was added as a solvent. After ultrasonic dissolution and homogenization, an appropriate amount of triethylamine was added. At the same time, 32 mmol of cyanuric chloride (TCT), 5.9 g, was dissolved in 50 ml of THF. After both were completely dissolved, they were pre-cooled in an ice bath for 30 min, then the TCT solution was added dropwise to the PPD solution, and the reaction was carried out at 0 °C for 2 h; after the reaction was completed, the reaction was continued at room temperature for 24 h; finally, the temperature was raised to 60 °C, and the reaction was carried out under reflux condensation for 24 h. Nitrogen was passed through the whole reaction as a protective gas. After the reaction was completed, the product was centrifugally washed three times with ethanol, 2M HCl and ultrapure water respectively to remove impurities and excess reactants in the product, and finally dried overnight in a vacuum oven at 60 °C to obtain a light brown powder. The synthesized triazine-based microporous polymer was named N-CTF.
[0042] The triazine-based microporous polymer prepared above was used as a nitrogen-containing precursor. 1 g of the product was added to a porcelain boat and heated under N 2 The temperature was raised to 1000°C at a rate of 2° / min in a gas atmosphere, kept at this temperature for 2 hours, cooled naturally to room temperature, and the porcelain boat was taken out to obtain black carbide, which was finally washed three times by centrifugation with ethanol and ultrapure water respectively, and then dried and ground in a vacuum oven at 60°C. The obtained triazine-based nitrogen-doped carbon material was named sample 4.
[0043] Performance Test:
[0044] The SEM images of samples 1, 2, 3, and 4 are shown in Figure 2. Figures 1 to 4 .
[0045] The nitrogen adsorption-desorption isotherm curves of the four samples were tested. The nitrogen adsorption-desorption isotherm curves were as follows: Figure 5 As shown:
[0046] After calculation, the specific surface areas of samples 1, 2, 3, and 4 are 704, 947, 1169, and 753 m 2 / g, and the total pore volumes were 0.54, 0.57, 0.60, and 0.55 cm 3 / g. In addition, the element contents of the four carbon materials were analyzed by X-ray energy dispersive spectrometer (EDS), and it was found that their nitrogen contents were 11.57%, 6.41%, 5.49%, and 1.29%, respectively.
[0047] Prepare four portions of 50 mg / L lead nitrate solution, each with 100 mL, add 50 mg of nitrogen-doped carbon material to each portion, seal and adsorb at 100 RPM in a 25-degree constant temperature water bath oscillator for 24 hours. After the oscillation is completed, filter out the powdered carbon material, and analyze the solution concentration by inductively coupled plasma emission spectrometer. Calculate the adsorption amount according to the following formula:
[0048] Q t =(C 0 -C t )V / m
[0049] Among them, Q t is the lead ion adsorption capacity, unit is mg / g; C 0 and C t are the initial lead ion concentration and the concentration after adsorption, respectively, in mg / L; m is the mass of the adsorbent carbon material, in g; V is the volume of the solution.
[0050] After analysis, it can be known that the adsorption amounts of the four nitrogen-doped carbon materials 1, 2, 3, and 4 are 45.5 mg / g, 54.6 mg / g, 68.9 mg / g, and 55.9 mg / g respectively. Generally, the adsorption amount of the porous activated carbon material without nitrogen doping is usually lower than 30 mg / g. Therefore, the method described in the present invention has certain application value.
[0051] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.
Claims
1. Application of a nitrogen-containing porous carbon material, Characterized in that, p-Phenylenediamine and cyanuric chloride are used as reactants, and triethylamine is used as an acid-binding agent to generate a microporous polymer with a triazine structure, and then the nitrogen-containing porous carbon material is obtained by high-temperature carbonization, and the nitrogen-containing porous carbon material is used for heavy metal ion adsorption.
2. The application of the nitrogen-containing porous carbon material according to claim 1, Characterized in that, The heavy metal ion is a lead ion.
3. The application of the nitrogen-containing porous carbon material according to claim 2, Characterized in that, The nitrogen-containing porous carbon material is added to a lead nitrate solution for shaking adsorption.
4. The application of the nitrogen-containing porous carbon material according to claim 3, Characterized in that, The mass ratio of the nitrogen-containing porous carbon material to lead nitrate is 8-12:
1.
5. The application of the nitrogen-containing porous carbon material according to claim 1, Characterized in that, The specific surface area of the nitrogen-containing porous carbon material is 700-1200 m 2 / g, the total pore volume is 0.5-0.6 cm 3 / g, and the nitrogen content is 1-12 wt%.
6. The application of the nitrogen-containing porous carbon material according to claim 1, Characterized in that, p-Phenylenediamine and cyanuric chloride are respectively dissolved in a solvent to obtain a p-phenylenediamine solution and a cyanuric chloride solution. Triethylamine is added to the p-phenylenediamine solution, and then the cyanuric chloride solution is added dropwise to the p-phenylenediamine solution for reaction.
7. The application of the nitrogen-containing porous carbon material according to claim 6, Characterized in that, Before adding the cyanuric chloride solution dropwise to the p-phenylenediamine solution, the cyanuric chloride solution and the p-phenylenediamine solution containing triethylamine are pre-cooled in an ice bath.
8. The application of the nitrogen-containing porous carbon material according to claim 7, Characterized in that, After adding the cyanuric chloride solution dropwise to the p-phenylenediamine solution, the reaction is carried out at 0 °C for 1.5-2.5 h. After the reaction is completed, the reaction is continued at room temperature for 20-30 h, and finally the temperature is raised to 50-70 °C, and the reaction is carried out under reflux condensation for 20-30 h.
9. The application of the nitrogen-containing porous carbon material according to claim 1, Characterized in that, p-Phenylenediamine and cyanuric chloride are in an equimolar ratio.
10. The application of the nitrogen-containing porous carbon material according to claim 1, Characterized in that, The high-temperature carbonization temperature is 700-1000 °C, and the time is 1.5-2.5 h; During the high-temperature carbonization process, the temperature is raised to the carbonization temperature at a heating rate of 2 °C / min in a protective atmosphere.