Carbon catalysts and synthesis methods and applications

Abstract

The application discloses a carbon catalyst and a synthesis method and application thereof. Pullulan is mixed and dissolved with a sodium hydroxide solution, then dopamine hydrochloride and a crosslinking agent are added in sequence, and the mixture is uniformly dispersed and then is placed for solidification at constant temperature to obtain a brown hydrogel; the hydrogel is divided into small pieces and then is calcined at high temperature to obtain the carbon catalyst. The carbon catalyst prepared by the application does not contain metal ions, does not cause secondary pollution to the environment, can be used for catalyzing and activating peroxymonosulfate to release a large number of active free radicals, thereby efficiently oxidizing and degrading antibiotics, and has excellent cycle performance and can be repeatedly used.

Description

Technical Field

[0001] This invention belongs to the field of organic pollution degradation catalyst preparation technology, specifically relating to a carbon catalyst, its synthesis method, and its application. Background Technology

[0002] In recent years, the emergence of antibiotics as a new type of organic pollutant in natural aquatic environments has attracted widespread attention from scholars both domestically and internationally. Antibiotics are widely used and consumed in large quantities as drugs for treating infectious diseases. However, after entering the human or animal body, 5%-90% of antibiotics are excreted in their parent form or as metabolites through urine or feces. For example, 30% of norfloxacin and 70% of ofloxacin fail to be metabolized and are excreted in urine; 55% of roxithromycin and 65% of azithromycin are excreted in their parent form through feces. Therefore, the large-scale use of antibiotics can easily lead to their entry into the environment through direct or indirect routes, causing environmental pollution and harming the health of organisms.

[0003] Currently, antibiotics have been detected in natural water environments in many parts of the world. Although the concentration of antibiotics in natural water environments is relatively low, their potential harm to ecosystems and human health cannot be ignored. With the frequent detection of antibiotics in natural water environments, research on their hazards is also increasing. Current studies report that the hazards of antibiotics in natural water environments are mainly attributed to three aspects: biotoxicity, induction of drug-resistant bacteria or drug-resistant genes, and threats to drinking water safety. Therefore, it is necessary to strengthen the degradation of antibiotics and other organic pollutants.

[0004] Due to the properties of antibiotics, they are difficult to degrade and remove using traditional methods. Currently, advanced oxidation technologies are generally used for degradation. However, advanced oxidation technologies such as Fenton oxidation, ozone catalytic oxidation, and photocatalytic oxidation all have certain limitations. Therefore, persulfate advanced oxidation technology is currently used for deep and long-term treatment of trace organic pollutants in water. This technology mainly involves the catalytic production of SO4 from persulfate through a catalyst. - ·、·OH、O2· and 1 O2 and other reactive oxygen species oxidize and degrade pollutants. Studies have found that specific activation methods can generate more ·OH and SO4 from persulfate. - • Free radicals. Persulfate activation methods generally employ metal catalysts, such as those used by Wang Hongbin et al. using Fe... 2+Activated persulfate degradation of diclofenac sodium (DCF) in water (Wang Hongbin, Wang Qun, Liu Yiqing, et al. Ferrous activated persulfate degradation of diclofenac sodium in water [J]. Environmental Chemistry, 2020, 39(4):869-875.); CN113042105B discloses a method for preparing a beaded catalyst of hydroxyapatite nanowires combined with cobalt MOFs. The method involves adding hydroxyapatite nanowires to a cobalt ion dispersion and ultrasonically mixing them, then adding a ligand solution to finally obtain a beaded purple catalyst, which can catalyze the degradation of antibiotics by persulfate and has excellent degradation removal rate and cycle stability; CN114939410B prepared a cobalt nanoparticle-embedded nitrogen-doped carbon porous catalyst, which has excellent catalytic performance in the degradation of sulfonamide antibiotics such as SMZ by PMS activation; CN114029078B prepared a magnetic silver and black phosphorus quantum dot co-modified bismuth ferrite composite catalyst using silver nitrate, bismuth ferrite precursor and black phosphorus quantum dots, which can rapidly activate persulfate oxidation to degrade antibiotic wastewater.

[0005] However, the aforementioned homogeneous transition metal catalysts are highly dependent on the pH of the solution and pose a risk of metal leakage, easily causing secondary pollution. As a novel heterogeneous PS catalyst, carbon materials possess characteristics such as being metal-free, having high utilization rates, being acid and alkali resistant, having ultra-high pore volume, and large specific surface area, exhibiting strong application potential. Therefore, the synthesis and modification of carbon materials have attracted considerable attention. Carbon materials exist in various forms, such as activated carbon, biomass carbon, carbon nanotubes, and graphene. Due to differences in carbon structure, these materials exhibit varying catalytic activation performance of persulfate. However, the preparation methods for graphene and carbon nanotubes are complex and costly, requiring the use of strong acids and strong oxidizing agents during preparation, demanding high operator skill and posing a risk of danger. While activated carbon and biomass carbon are inexpensive and readily available, their catalytic activity is relatively low and easily affected by the type of biomass and production conditions.

[0006] Therefore, there is an urgent need for a safe, environmentally friendly, highly catalytically active, stable and readily available catalyst to activate persulfate and improve the degradation efficiency of organic pollutants, especially antibiotics. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a method for synthesizing and applying a carbon catalyst. A hydrogel is prepared under alkaline conditions using a crosslinking agent, polysaccharide, and dopamine, and then calcined to obtain a green, pure carbon catalyst. This catalyst can catalyze the activation of persulfate to release a large number of active free radicals, thereby improving the degradation rate of organic pollutants. It has advantages such as being environmentally friendly, having a simple process, high catalytic activation rate, and being reusable.

[0008] To achieve the above objectives, the present invention provides a method for synthesizing a carbon catalyst, comprising the following steps:

[0009] (1) Preparation of alkaline solution: Dissolve sodium hydroxide in water to prepare an alkaline solution;

[0010] (2) Add the polysaccharide to the alkaline solution obtained in step (1), mix it with ultrasound, then add dopamine and mix well to obtain a mixture;

[0011] (3) Add a crosslinking agent to the mixture, mix well, and let it stand at a constant temperature to solidify, thus obtaining a hydrogel;

[0012] (4) The hydrogel was divided into small pieces and calcined to obtain a carbon catalyst.

[0013] Preferably, the concentration of the alkaline solution in step (1) is 0.6-1.8 mol / L.

[0014] Preferably, the mass ratio of the polysaccharide, dopamine and sodium hydroxide in the alkaline solution in step (2) is 5-15:1-3:1.2-3.6.

[0015] More preferably, the polysaccharide is pullulan.

[0016] More preferably, the dopamine is dopamine hydrochloride.

[0017] Preferably, the crosslinking agent in step (3) is ethylene glycol diglycidyl ether, and the volume ratio of the crosslinking agent to the mixed solution is 1:12.5-40.

[0018] Preferably, the constant temperature settling time in step (3) is 20-50℃ and the time is 6-15h.

[0019] Preferably, the calcination temperature in step (4) is 500-600℃ and the calcination time is 1-4h.

[0020] The present invention also provides a carbon catalyst synthesized using the above-described synthesis method.

[0021] The present invention also provides the application of a carbon catalyst in activating persulfate to degrade organic pollutants, wherein the organic pollutant is an antibiotic, and the antibiotic includes any one of tetracycline, oxytetracycline, and chlortetracycline hydrochloride.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. A hydrogel was prepared using polysaccharides, dopamine, and a crosslinking agent. Then, a pure carbon catalyst was synthesized by calcination. Without the addition of metal doping, it can still efficiently catalyze the activation of persulfate to generate free radicals, which degrade organic pollutants such as antibiotics. This process converts large toxic molecules into non-toxic small molecules, or even directly into water and carbon dioxide, thereby reducing environmental pollution.

[0024] 2. The prepared carbon catalyst is a gray-black powder that can be reused to catalyze the activation of persulfate. After being reused 5 times, it can still catalyze the activation of persulfate to effectively degrade antibiotic pollutants such as tetracycline. The removal rate of tetracycline can still reach about 80% after 20 minutes. It has good stability and reusability, so it has good application prospects in the field of degrading organic pollutants.

[0025] 3. Compared with traditional single-metal or multi-metal supported catalysts, the carbon catalyst prepared by this invention does not contain any metals, which can effectively avoid the secondary pollution caused by metal leaching to the natural environment and is more environmentally friendly. Moreover, no strong acids or strong oxidants are used in the preparation process, so it is highly safe. It also has the advantages of simple preparation process, small dosage and low cost. Attached Figure Description

[0026] Figure 1 This is a transmission electron microscope (TEM) image of the carbon catalyst prepared in Example 1.

[0027] Figure 2 The X-ray diffraction patterns are those of the carbon catalysts prepared in Examples 1, 4, and 5.

[0028] Figure 3 The electron paramagnetic resonance spectrum of persulfate activated by the carbon catalyst in Example 9 is shown.

[0029] Figure 4 The UV-Vis absorption spectra of tetracycline at different sampling times during the carbon catalyst activation of persulfate in Example 10.

[0030] Figure 5 This is a comparison chart showing the rate of tetracycline degradation by persulfate activated by carbon catalysts prepared under different conditions in Example 11.

[0031] Figure 6 This is a comparison chart showing the rate of tetracycline degradation by persulfate activated by carbon catalysts prepared under different conditions in Example 11.

[0032] Figure 7 This is a comparison chart of the rate of tetracycline degradation by the carbon catalyst prepared in Example 12 using repeated cycles.

[0033] Figure 8 The image shows the UV-Vis absorption spectrum of chlortetracycline hydrochloride degraded by carbon catalyst activated by persulfate in Example 13. In the image, A is the chemical structural formula of chlortetracycline hydrochloride, and B is the UV-Vis absorption spectrum of chlortetracycline hydrochloride at different sampling times.

[0034] Figure 9The image shows the UV-Vis absorption spectrum of oxytetracycline degraded by persulfate activated by the carbon catalyst in Example 14. In the image, A is the chemical structural formula of oxytetracycline, and B is the UV-Vis absorption spectrum of oxytetracycline at different sampling times. Detailed Implementation

[0035] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. It is worth noting that the following embodiments are only preferred embodiments of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention should be determined by the contents of the claims. Modifications and substitutions made by those skilled in the art to the technical solution of the present invention without creative effort all fall within the scope of protection of the present invention.

[0036] Pullulan, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with a purity of 98%;

[0037] Dopamine hydrochloride, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with a purity of 98%;

[0038] Ethylene glycol diglycidyl ether, purchased from Jiuding Chemical Technology Co., Ltd., with a purity of 99%.

[0039] Example 1

[0040] (1) Dissolve solid sodium hydroxide in deionized water and stir at room temperature to prepare a 1.2 mol / L sodium hydroxide solution;

[0041] (2) Dissolve pullulan in the sodium hydroxide solution obtained in step (1), and mix by ultrasonication to obtain a white mixed solution, wherein the mass ratio of pullulan to sodium hydroxide is 5:1.2;

[0042] (3) Add dopamine hydrochloride to the white mixed solution prepared in step (2) and mix it with ultrasound to obtain a brown mixed solution, wherein the mass ratio of dopamine hydrochloride to pullulan is 1:5;

[0043] (4) Add ethylene glycol diglycidyl ether to the brown mixed solution prepared in step (3), stir evenly, and place in a 30°C water bath for 12 hours to obtain a brown hydrogel; wherein the volume ratio of ethylene glycol diglycidyl ether to the mixed solution is 1:20.

[0044] (5) The brown hydrogel was divided into small pieces and then placed in a tube furnace and calcined at 550°C for 3 hours. After grinding, a gray-black powder was obtained, which is the carbon catalyst NCN-550°C.

[0045] Depend on Figure 1 It can be seen that the carbon catalyst NCN-550℃ has a nanoneedle-rod structure, which is composed of... Figure 2It can be seen that the carbon catalyst NCN-550℃ has a corresponding crystal plane of C3N4, indicating that the prepared carbon catalyst is a novel carbon structure similar to C3N4.

[0046] Example 2

[0047] The method and steps are the same as in Example 1, except that the mass of sodium hydroxide, pullulan, and dopamine hydrochloride are halved, and the volume of ethylene glycol diglycidyl ether is halved. The carbon catalyst NCN is prepared by calcination at 550°C. 0.5 -550℃.

[0048] Example 3

[0049] The method and steps are the same as in Example 1, except that the mass of sodium hydroxide, pullulan, and dopamine hydrochloride is increased by half, and the volume of ethylene glycol diglycidyl ether is increased to 1.5 times. The carbon catalyst NCN is prepared by calcination at 550°C. 1.5 -550℃.

[0050] Example 4

[0051] The method and steps are the same as in Example 1, except that the calcination temperature in step (5) is changed to 500℃ to prepare the carbon catalyst NCN-500℃.

[0052] Example 5

[0053] The method and steps are the same as in Example 1, except that the calcination temperature in step (5) is changed to 600℃ to prepare the carbon catalyst NCN-600℃.

[0054] Example 6

[0055] (1) Dissolve solid sodium hydroxide in deionized water and stir at room temperature to prepare a 0.6 mol / L sodium hydroxide solution;

[0056] (2) Dissolve pullulan in the sodium hydroxide solution obtained in step (1) and mix by ultrasonication to obtain a white mixed solution; wherein the mass ratio of pullulan to sodium hydroxide is 10:1.2;

[0057] (3) Add dopamine hydrochloride to the white mixed solution prepared in step (2) and mix it with ultrasound to obtain a brown mixed solution, wherein the mass ratio of dopamine hydrochloride to pullulan is 1:5;

[0058] (4) Add ethylene glycol diglycidyl ether to the brown mixed solution prepared in step (3), stir evenly, and place in a 20°C water bath for 15 hours to obtain a brown hydrogel; wherein the volume ratio of ethylene glycol diglycidyl ether to the mixed solution is 1:25;

[0059] (5) The brown hydrogel was divided into small pieces, and then placed in a tube furnace and calcined at 500°C for 1 hour. After grinding, a gray-black powder was obtained, which is the carbon catalyst.

[0060] Example 7

[0061] (1) Dissolve solid sodium hydroxide in deionized water and stir at room temperature to prepare a 1.2 mol / L sodium hydroxide solution;

[0062] (2) Dissolve pullulan in the sodium hydroxide solution obtained in step (1) and mix by ultrasonication to obtain a white mixed solution; wherein the mass ratio of pullulan to sodium hydroxide is 5:1.2;

[0063] (3) Add dopamine hydrochloride to the white mixed solution prepared in step (2) and mix it with ultrasound to obtain a brown mixed solution, wherein the mass ratio of dopamine hydrochloride to pullulan is 3:10;

[0064] (4) Add ethylene glycol diglycidyl ether to the brown mixed solution prepared in step (3), stir evenly, and place in a 40°C water bath for 10 hours to obtain a brown hydrogel; wherein the volume ratio of ethylene glycol diglycidyl ether to the mixed solution is 3:50;

[0065] (5) The brown hydrogel was divided into small pieces, and then placed in a tube furnace and calcined at 550°C for 2 hours. After grinding, a gray-black powder was obtained, which is the carbon catalyst.

[0066] Example 8

[0067] (1) Dissolve solid sodium hydroxide in deionized water and stir at room temperature to prepare a 1.8 mol / L sodium hydroxide solution;

[0068] (2) Dissolve pullulan in the sodium hydroxide solution obtained in step (1) and mix by ultrasonication to obtain a white mixed solution; wherein the mass ratio of pullulan to sodium hydroxide is 5:1.2;

[0069] (3) Add dopamine hydrochloride to the white mixed solution prepared in step (2) and mix it with ultrasound to obtain a brown mixed solution, wherein the mass ratio of dopamine hydrochloride to pullulan is 1:5;

[0070] (4) Add ethylene glycol diglycidyl ether to the brown mixed solution prepared in step (3), stir evenly, and place in a 50℃ water bath for 6 h to obtain a brown hydrogel; wherein the volume ratio of ethylene glycol diglycidyl ether to the mixed solution is 2:25;

[0071] (5) The brown hydrogel was divided into small pieces, and then placed in a tube furnace and calcined at 600°C for 4 hours. After grinding, a gray-black powder was obtained, which is the carbon catalyst.

[0072] Comparative Example 1

[0073] The method and steps are the same as in Example 1, except that pullulan is replaced with chitosan. During the preparation process, it was found that no hydrogel could be formed after adding ethylene glycol diglycidyl ether, no matter how long it was left to stand. Therefore, it was impossible to obtain a carbon catalyst by calcination.

[0074] Comparative Example 2

[0075] The method and steps are the same as in Example 1, except that the hydrogel prepared in step (4) is not calcined and magnetic hydrogel material synthesized from iron oxide is added directly as a catalyst. When applied to the tetracycline degradation experiment, it was found to have a good degradation efficiency at 60 min, with a tetracycline removal rate of 86.32%.

[0076] Example 9: Electron paramagnetic resonance to determine the type of free radicals generated during activation.

[0077] Carbon catalysts can activate persulfate to generate free radicals, among which singlet oxygen can oxidize 2,2,6,6-tetramethyl-4-piperidinol (TEMP) to generate paramagnetic 4-hydroxy-2,2,6,6-tetramethyl-piperidinoxy (TEMPO). Therefore, electron paramagnetic resonance (EPR) can be used to detect and identify whether a 1:1:1 singlet oxygen characteristic signal peak is generated.

[0078] The results are as follows Figure 3 As shown 1 O2 has significant strength; this single free radical participates in the degradation process of organic matter, and •O2 - •OH, •SO4 - The absence of a distinct peak intensity indicates the absence of these three free radicals in the reaction system. This suggests that the carbon catalyst activating persulfate produces... 1 O2 is a free radical, which enables the degradation of organic pollutants.

[0079] Example 10: Carbon catalyst activation experiment of persulfate

[0080] The carbon catalyst used in Example 1 was activated to degrade tetracycline using persulfate. The specific method is as follows:

[0081] (1) Take 50 mL of 20 mg / L tetracycline solution and add it to a 100 mL round bottom flask. Add carbon catalyst and stir for 10 min. Test and record the absorption peak of tetracycline. The concentration of carbon catalyst is 0.5 g / L.

[0082] (2) Quickly add persulfate to the round-bottom flask containing tetracycline solution and carbon catalyst in step (1) to make its concentration 0.5 g / L. Take 3 mL of solution at regular intervals and place it in a cuvette. Use a UV-Vis spectrophotometer to measure the peak value of the UV-Vis absorption spectrum of tetracycline.

[0083] Samples were taken at 0 min before the addition of persulfate, and at 1 min, 3 min, 5 min, 10 min, 15 min, and 20 min after addition. The characteristic peak of tetracycline was detected, and the results are as follows: Figure 4 As shown, the characteristic peak of tetracycline is at 360 nm. With the extension of the addition time, the peak value of the tetracycline characteristic peak gradually decreases. When persulfate is added for 15-20 minutes, its peak value no longer decreases significantly, indicating that the reaction is basically terminated after 20 minutes of persulfate addition.

[0084] Example 11 Tetracycline Degradation Experiment

[0085] The carbon catalysts or hydrogels prepared in Examples 1-5 and Comparative Examples 2-4 were used to degrade tetracycline, and the specific methods were the same as in Example 9.

[0086] The results showed that the carbon catalysts prepared in Examples 1-3 using different concentrations and calcination temperatures could effectively degrade tetracycline. Among them, the carbon catalyst prepared in Example 1 activated persulfate and achieved a 92% removal rate of tetracycline within 20 minutes. Figure 5 ).

[0087] The carbon catalysts prepared in Examples 1, 4, and 5 using different calcination temperatures can all activate persulfate to effectively degrade tetracycline, and the degradation rates are not significantly different. Among them, the carbon catalyst prepared in Example 1 using calcination at 550℃ has the highest catalytic degradation rate, and the tetracycline removal rate can reach 92%. Figure 6 ).

[0088] Example 12 Catalyst Recycling Experiment

[0089] The method and steps are the same as in Example 10, except that after the peak value of the ultraviolet-visible absorption spectrum of tetracycline measured in step (2) is flattened, the carbon catalyst in the solution is quickly filtered out, and washed once by centrifugation with 2 mol / L sodium hydroxide solution and then vacuum dried. Then the tetracycline degradation experiment is repeated for a total of 5 cycles, and the degradation rate of tetracycline in each cycle is counted.

[0090] The results are as follows Figure 7As shown, compared with the first degradation, the rate of tetracycline degradation by repeated use of carbon catalyst for persulfate catalysis decreased, but overall remained at a high level. After 5 cycles, the tetracycline removal rate reached 75.86% at 20 minutes, indicating that the carbon catalyst still maintained good degradation performance after 5 cycles. The carbon catalyst prepared in this invention can activate persulfate to convert large organic pollutants into green, pollution-free small molecules, and even directly into water and carbon dioxide.

[0091] Example 13 Degradation experiment of chlortetracycline hydrochloride

[0092] The carbon catalyst prepared in Example 1 was used to activate persulfate, which generated free radicals to degrade chlortetracycline hydrochloride. The specific method is as follows:

[0093] (1) Take 50 mL of 10 mg / L chlortetracycline hydrochloride solution and add it to a 100 mL round bottom flask. Add the carbon catalyst prepared in Example 1 and stir for 10 min. Record the absorption peak of chlortetracycline hydrochloride at this time. The concentration of carbon catalyst is 0.5 g / L.

[0094] (2) Quickly add persulfate (0.25 g / L) to the round bottom flask. At certain intervals, take out 3 mL and add it to the cuvette. Use a UV-Vis spectrophotometer to measure the peak value of the UV-Vis absorption spectrum of chlortetracycline hydrochloride.

[0095] The results are as follows Figure 8 As shown, the characteristic peak of chlortetracycline hydrochloride was detected at a wavelength of 364 nm. It was also found that the absorbance of chlortetracycline hydrochloride at 364 nm remained almost unchanged after 10 min of the addition of persulfate, indicating that the degradation reaction terminated after 10 min.

[0096] Example 14 Degradation experiment of oxytetracycline

[0097] The carbon catalyst prepared in Example 1 was used to activate persulfate, generating free radicals to degrade chlortetracycline hydrochloride. The specific method was the same as in Example 13, except that the 10 mg / L chlortetracycline hydrochloride solution was replaced with a 20 mg / L oxytetracycline solution. The results are as follows: Figure 9 As shown, the characteristic peak of oxytetracycline was detected at a wavelength of 352 nm. It was also found that the absorbance of oxytetracycline at 352 nm remained almost unchanged after 15 min of the addition of persulfate, indicating that the degradation reaction terminated after 15 min.

[0098] Comparative Example 3

[0099] Oxygen-doped carbon nitride (P-C3N4) prepared by grinding and mixing hexachlorotriphosphononitrile and urea and then calcining it was used directly as a catalyst. When applied to the experiment of activating peroxymonosulfate to degrade tetracycline, it was found to have a good degradation efficiency at 60 min, with a tetracycline removal rate of 77.35% (Liquan Wang, Ruyi Li, Yimin Zhang et al. Phosphorusdoping to enhance the peroxymonosulfate activation efficiency of carbonnitride for degrading tetracycline. Journal of Water Process Engineering. 54(3):103916).

Claims

1. A method for synthesizing a carbon catalyst, characterized in that: Includes the following steps: (1) Preparation of alkaline solution: Dissolve sodium hydroxide in water to prepare an alkaline solution; (2) Add the polysaccharide to the alkaline solution obtained in step (1), mix it with ultrasound, then add dopamine and mix well to obtain a mixture; (3) Add a crosslinking agent to the mixture, mix well, and let it stand at a constant temperature to solidify, thus obtaining a hydrogel; (4) The hydrogel was divided into small pieces and calcined to obtain a carbon catalyst; The mass ratio of the polysaccharide, dopamine, and sodium hydroxide in the alkaline solution in step (2) is 5-15:1-3:1.2-3.6; The polysaccharide is pullulan polysaccharide; the dopamine is dopamine hydrochloride.

2. The method for synthesizing a carbon catalyst according to claim 1, characterized in that: The concentration of the alkaline solution in step (1) is 0.6-1.8 mol / L.

3. The method for synthesizing a carbon catalyst according to claim 1, characterized in that: The crosslinking agent in step (3) is ethylene glycol diglycidyl ether, and the volume ratio of the crosslinking agent to the mixed solution is 1:12.5-40.

4. The method for synthesizing a carbon catalyst according to claim 1, characterized in that: The constant temperature settling time in step (3) is 20-50℃ and the time is 6-15h.

5. The method for synthesizing a carbon catalyst according to claim 1, characterized in that: The calcination temperature in step (4) is 500-600℃ and the calcination time is 1-4h.

6. A carbon catalyst synthesized by the synthesis method according to any one of claims 1-5.

7. The application of the carbon catalyst according to claim 6 in activating persulfate and degrading organic pollutants, characterized in that: The organic pollutant is an antibiotic, including any one of tetracycline, oxytetracycline, and chlortetracycline hydrochloride.

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