A method for preparing boron-doped carbon-based iron monatomic material through two-step calcination and application

Abstract

The present application relates to a kind of preparation method and application of boron-doped carbon-based iron monatomic material by two-step calcination.The method uses polyether F127 as soft template, iron chloride hexahydrate as iron source, and chitin as nitrogen and carbon source.By two-step pyrolysis method, boron-doped carbon-based iron monatomic material is synthesized by mixing, calcining and grinding.The material prepared by the present application retains the high crystalline fiber sheet structure of chitin.When applied to persulfate-based advanced oxidation technology, it can completely remove the antibiotic sulfamethoxazole in water within 50 min.The synthesis method proposed in the present application introduces boron atoms into carbon-based iron monatomic material, and the prepared material has excellent catalyst performance, which can provide a new idea for the structural design of carbon-based iron monatomic nanomaterials and be applied to water pollution remediation.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of functional nanomaterials and technologies, and particularly relates to a boron-doped chitin-derived carbon-based iron monatomic material as well as a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of monatomic catalyst research, monatomic materials have gradually become a research hotspot in the field of environmental pollution treatment due to their high atom utilization rate, uniform active site distribution and excellent catalytic performance. Especially in the fields of wastewater treatment, organic pollutant degradation and energy conversion, monatomic catalysts have shown great potential. However, although iron monatomic catalysts have been widely used in environmental catalytic reactions due to their abundant crustal resources, low cost and good catalytic activity, there are still some limitations in the actual application process, such as insufficient stability of iron monatomic on the carrier and limited catalytic activity.

[0003] In recent years, carbon-based materials have become good monatomic carrier materials due to their excellent electrical conductivity, structural adjustability and large specific surface area. By doping other elements in carbon-based materials, the electronic structure can be further regulated, and the catalytic performance and stability of monatomic can be improved. For example, boron, as a trivalent element, can cause electron rearrangement around carbon atoms when doped in carbon-based materials, break the sp 2 structure of carbon materials, make the electrons delocalized and enhance the catalytic activity. In addition, boron doping can effectively improve the electrochemical performance of the material and enhance the stability of iron monatomic on the carbon carrier, thereby improving the catalytic efficiency. Based on this, the application uses iron chloride hexahydrate as an iron source and chitin as a nitrogen-carbon source to synthesize a boron-doped carbon-based iron monatomic material through a soft template and two-step calcination method. First, the doping of boron atoms can effectively break the local structure of carbon materials, making the distribution of iron monatomic on the carbon-based material more uniform, while improving the electrical conductivity and activity of the material. Second, boron doping can also improve the electronic structure of iron monatomic, further enhancing the efficiency of the catalytic reaction. In addition, chitin itself contains nitrogen and has a natural and special three-dimensional network structure, which provides a good environment for metal coordination. In summary, the application provides a new design idea and technical method reference for the same type of non-metallic doped carbon-based monatomic nanomaterials. SUMMARY

[0004] The purpose of the application is to overcome the deficiencies of the prior art and provide a preparation method and application of a boron-doped carbon-based iron monatomic material.

[0005] The purpose of the application is achieved by the following technical solutions:

[0006] In a first aspect, the present application provides a method for preparing boron-doped carbon-based iron single-atom material by two-step calcination, comprising the following steps:

[0007] Step one: Put the carbon-based reagent, iron reagent and soft template into anhydrous ethanol respectively;

[0008] Step two: ultrasonic the carbon-based reagent solution, iron reagent solution and soft template solution obtained in step one, then put them into oil bath pot and heat to 55-70℃ respectively;

[0009] Step three: add the heated iron reagent solution and soft template solution into the heated carbon-based reagent solution, wait for the ethanol to evaporate, and then put it into the oven for drying;

[0010] Step four: put the material obtained in step three into a quartz boat, pass 10-30min of argon through the inner pipeline of the tube furnace to expel all air in the pipeline, raise the temperature to 800-850℃ at a rate of 9-10℃ / min, and keep for 2-2.5h, then cool to room temperature and take out;

[0011] Step five: grind the solid obtained in step four, wash with water and ethanol for 3-4 times respectively, and then put it into a vacuum drying box for drying for 16-36h;

[0012] Step six: grind the dried material prepared in step five into powder, take 350-450mg of the powder, then add 40-120mg of boric acid and grind thoroughly;

[0013] Step seven: put the mixture obtained in step six into a quartz boat, pass 10-30min of argon through the inner pipeline of the tube furnace to expel all air in the pipeline, raise the temperature to 400-450℃ at a rate of 9-10℃ / min, and keep for 2-2.5h, then cool to room temperature and take out;

[0014] Step eight: grind the solid obtained in step seven, wash with water and ethanol for 3-4 times respectively, and then put it into a vacuum drying box for drying for 16-36h;

[0015] Step nine: grind the dried material prepared in step eight into powder to obtain boron-doped carbon-based iron single-atom material.

[0016] In the above method, the iron reagent includes ferric chloride hexahydrate; the carbon-based reagent includes chitin; the soft template includes polyether F127; the method used is soft template + two-step calcination strategy. In the present application, polyether F127 is used as the soft template, ferric chloride trihydrate is used as the iron source, and chitin is used as the nitrogen and carbon source.

[0017] In the above method, in step two, the ultrasonic time is 20-30min.

[0018] In the above method, in step three, the temperature of drying in the oven is 50-70℃.

[0019] Further, the iron reagent comprises ferric chloride hexahydrate, the carbon-based reagent comprises chitin, the soft template comprises polyether F127, and the method used is a soft template + two-step calcination strategy.

[0020] In a second aspect, the present application provides a boron-doped carbon-based iron monatomic material prepared by the above method.

[0021] In a third aspect, the present application provides an application of a boron-doped carbon-based iron monatomic material, which is used for efficient degradation of sulfamethoxazole.

[0022] Further, the application comprises the following steps:

[0023] (1) Dissolve sulfamethoxazole in a beaker and obtain a sulfamethoxazole pollution solution by constant volume in a volumetric flask;

[0024] (2) Put the boron-doped carbon-based iron monatomic material into the conical flask containing the sulfamethoxazole pollutants in step (1) and perform magnetic stirring;

[0025] (3) Add a PMS reagent to the conical flask containing the material and pollutants in step (2).

[0026] Further, the concentration of sulfamethoxazole in the sulfamethoxazole pollution solution in step (1) is 3-5 mg / L, preferably 5 mg / L.

[0027] Further, the dosage of the boron-doped carbon-based iron monatomic material in step (2) is 0.3-0.45 g / L.

[0028] Further, the dosage of the PMS reagent in step (3) is 0.6-1.2 mM.

[0029] The material prepared by the present application retains the high crystalline fiber sheet structure of chitin. When applied to the persulfate-based advanced oxidation technology, it can completely remove the antibiotic sulfamethoxazole in water within 50 min. The synthesis method proposed by the present application realizes the introduction of boron atoms into the carbon-based iron monatomic material, and the prepared material has excellent catalyst performance, which can provide a new idea for the structural design of carbon-based iron monatomic nanomaterials and be applied to the pollution remediation of water bodies.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] (1) The introduction of the soft template in the present application promotes the dispersion of iron monatomic;

[0032] (2) In this invention, the doping of boron atoms improves the electronic structure of iron single atoms, enhances the conductivity and activity of the material, and strengthens its catalytic activity;

[0033] (3) The method in this invention uses chitin with a special three-dimensional network structure as a nitrogen and carbon source, which not only realizes nitrogen self-doping, but also provides an excellent environment for iron coordination due to its rich biological functional groups.

[0034] (4) The method in this invention will not cause iron contamination due to the use of iron salts.

[0035] (5) In this invention, boron atoms are introduced into the carbon-based iron single-atom material through two-step calcination, which improves the excellent catalytic performance of iron single atoms and also enhances the stability of the material.

[0036] (6) The material in this invention has excellent removal performance of sulfamethoxazole in water. Attached Figure Description

[0037] Figure 1a and 1b These are scanning electron microscope images of carbon-based iron single-atom materials and boron-doped carbon-based iron single-atom materials, respectively.

[0038] Figure 2a and 2b These are transmission electron microscope images of carbon-based iron single-atom materials and boron-doped carbon-based iron single-atom materials, respectively.

[0039] Figure 3 This is a high-angle annular dark-field scanning transmission electron microscope image of boron-doped carbon-based iron single-atom material.

[0040] Figure 4 X-ray diffraction patterns of carbon-based iron single-atom materials and boron-doped carbon-based iron single-atom materials;

[0041] Figure 5a High-resolution XPS spectra of N1s for carbon-based iron single-atom materials and boron-doped carbon-based iron single-atom materials. Figure 5b High-resolution XPS spectrum of boron-doped carbon-based iron single-atom material (B1s);

[0042] Figure 6 In the figures (a), (b), and (c), respectively, the electrochemical impedance spectroscopy, tafe plot, and open-circuit voltage test results are presented for carbon-based iron single-atom materials and boron-doped carbon-based iron single-atom materials.

[0043] Figure 7 The graph shows the change in sulfamethoxazole concentration over time in the reaction system. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0045] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the reagents and materials described are commercially available unless otherwise specified.

[0046] Example 1: A carbon-based iron single-atom material (Fe-N) x / GCN) preparation

[0047] Step 1: Place 7g of chitosan, 50mg of ferric chloride hexahydrate and 0.7g of polyether F127 into anhydrous ethanol respectively;

[0048] Step 2: Sonicate the chitin solution, ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 1 for 20 minutes, and then heat them separately in an oil bath to 60°C.

[0049] Step 3: Add the ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 2 to the chitin solution obtained in Step 2, wait for the ethanol to evaporate to dryness, and then place it in an oven at 60°C to dry.

[0050] Step 4: After simply grinding the material obtained in Step 3, place it in a quartz boat. Purge the internal tubing of the tube furnace with argon gas for 20 minutes to purge all air from the tubing. Increase the temperature to 800°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0051] Step 5: Simply grind the solid obtained in Step 4, wash it three times each with water and ethanol, and then dry it in a vacuum drying oven for 24 hours;

[0052] Step Six: Grind the dried material obtained in Step Five into powder and place it in a quartz boat. Pour argon gas through the internal tubing of the tube furnace for 20 minutes to purge all air from the tubing. Increase the temperature to 400°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0053] Step 7: Simply grind the solid obtained in Step 6, wash it three times each with water and ethanol, and then dry it in a vacuum drying oven for 24 hours;

[0054] Step 8: Grind the dried material obtained in Step 7 into powder to obtain carbon-based iron single-atom material (Fe-N). x / GCN).

[0055] Example 2: A boron-doped carbon-based iron single-atom material (Fe-N) x Preparation of B / GCN4

[0056] Step 1: Place 7g of chitosan, 50mg of ferric chloride hexahydrate and 0.7g of polyether F127 into anhydrous ethanol respectively;

[0057] Step 2: Sonicate the chitin solution, ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 1 for 20 minutes, and then heat them separately in an oil bath to 60°C.

[0058] Step 3: Add the ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 2 to the chitin solution obtained in Step 2, wait for the ethanol to evaporate to dryness, and then place it in an oven at 60°C to dry.

[0059] Step 4: After simply grinding the material obtained in Step 3, place it in a quartz boat. Purge the internal tubing of the tube furnace with argon gas for 20 minutes to purge all air from the tubing. Increase the temperature to 800°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0060] Step 5: Simply grind the solid obtained in Step 4, wash it three times each with water and ethanol, and then dry it in a vacuum drying oven for 24 hours;

[0061] Step Six: Grind the dried material obtained in Step Five into powder, and weigh 400 mg of the powder. Then add 40 mg of boric acid and grind thoroughly to mix.

[0062] Step 7: Place the mixture obtained in Step 6 into a quartz boat, and purge all air from the tube furnace by passing argon gas through the internal tubing for 20 minutes. Increase the temperature to 400°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0063] Step 8: Simply grind the solid obtained in Step 7, wash it three times each with water and ethanol, and then put it into a vacuum drying oven to dry for 24 hours;

[0064] Step 9: Grind the dried material obtained in Step 8 into powder to obtain boron-doped carbon-based iron single-atom material (Fe-N). x B / GCN4).

[0065] In Example 2, the amount of boric acid used was 40 mg. Therefore, the boron-doped carbon-based iron single-atom material prepared in this example is labeled as Fe-N. x B / GCN4.

[0066] Example 3: A boron-doped carbon-based iron single-atom material (Fe-N) xPreparation of B / GCN6

[0067] Step 1: Place 7g of chitosan, 50mg of ferric chloride hexahydrate and 0.7g of polyether F127 into anhydrous ethanol respectively;

[0068] Step 2: Sonicate the chitin solution, ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 1 for 20 minutes, and then heat them separately in an oil bath to 60°C.

[0069] Step 3: Add the ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 2 to the chitin solution obtained in Step 2, wait for the ethanol to evaporate to dryness, and then place it in an oven at 60°C to dry.

[0070] Step 4: After simply grinding the material obtained in Step 3, place it in a quartz boat. Purge the internal tubing of the tube furnace with argon gas for 20 minutes to purge all air from the tubing. Increase the temperature to 800°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0071] Step 5: Simply grind the solid obtained in Step 4, wash it three times each with water and ethanol, and then dry it in a vacuum drying oven for 24 hours;

[0072] Step Six: Grind the dried material obtained in Step Five into powder, and weigh 400 mg of the powder. Then add 60 mg of boric acid and grind thoroughly until mixed.

[0073] Step 7: Place the mixture obtained in Step 6 into a quartz boat, and purge all air from the tube furnace by passing argon gas through the internal tubing for 20 minutes. Increase the temperature to 400°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0074] Step 8: Simply grind the solid obtained in Step 7, wash it three times each with water and ethanol, and then put it into a vacuum drying oven to dry for 24 hours;

[0075] Step 9: Grind the dried material obtained in Step 8 into powder to obtain boron-doped carbon-based iron single-atom material (Fe-N). x B / GCN6).

[0076] In Example 3, the amount of boric acid used was 60 mg. Therefore, the boron-doped carbon-based iron single-atom material prepared in this example is labeled as Fe-N. x B / GCN6.

[0077] Example 4: A boron-doped carbon-based iron single-atom material (Fe-N) x Preparation of B / GCN8

[0078] Step 1: Place 7g of chitosan, 50mg of ferric chloride hexahydrate and 0.7g of polyether F127 into anhydrous ethanol respectively;

[0079] Step 2: Sonicate the chitin solution, ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 1 for 20 minutes, and then heat them separately in an oil bath to 60°C.

[0080] Step 3: Add the ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 2 to the chitin solution obtained in Step 2, wait for the ethanol to evaporate to dryness, and then place it in an oven at 60°C to dry.

[0081] Step 4: After simply grinding the material obtained in Step 3, place it in a quartz boat. Purge the internal tubing of the tube furnace with argon gas for 20 minutes to purge all air from the tubing. Increase the temperature to 800°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0082] Step 5: Simply grind the solid obtained in Step 4, wash it three times each with water and ethanol, and then dry it in a vacuum drying oven for 24 hours;

[0083] Step Six: Grind the dried material obtained in Step Five into powder, and weigh 400 mg of the powder. Then add 80 mg of boric acid and grind thoroughly until mixed.

[0084] Step 7: Place the mixture obtained in Step 6 into a quartz boat, and purge all air from the tube furnace by passing argon gas through the internal tubing for 20 minutes. Increase the temperature to 400°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0085] Step 8: Simply grind the solid obtained in Step 7, wash it three times each with water and ethanol, and then put it into a vacuum drying oven to dry for 24 hours;

[0086] Step 9: Grind the dried material obtained in Step 8 into powder to obtain boron-doped carbon-based iron single-atom material (Fe-N). x B / GCN8).

[0087] In Example 4, the amount of boric acid used was 80 mg. Therefore, the boron-doped carbon-based iron single-atom material prepared in this example is labeled as Fe-N. x B / GCN8.

[0088] Example 5: A boron-doped carbon-based iron single-atom material (Fe-N) x Preparation of B / GCN12

[0089] Step 1: Place 7g of chitosan, 50mg of ferric chloride hexahydrate and 0.7g of polyether F127 into anhydrous ethanol respectively;

[0090] Step 2: Sonicate the chitin solution, ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 1 for 20 minutes, and then heat them separately in an oil bath to 60°C.

[0091] Step 3: Add the ferric chloride hexahydrate solution and polyether F127 solution obtained in Step 2 to the chitin solution obtained in Step 2, wait for the ethanol to evaporate to dryness, and then place it in an oven at 60°C to dry.

[0092] Step 4: After simply grinding the material obtained in Step 3, place it in a quartz boat. Purge the internal tubing of the tube furnace with argon gas for 20 minutes to purge all air from the tubing. Increase the temperature to 800°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0093] Step 5: Simply grind the solid obtained in Step 4, wash it three times each with water and ethanol, and then dry it in a vacuum drying oven for 24 hours;

[0094] Step Six: Grind the dried material obtained in Step Five into powder, and weigh 400 mg of the powder. Then add 120 mg of boric acid and grind thoroughly until mixed.

[0095] Step 7: Place the mixture obtained in Step 6 into a quartz boat, and purge all air from the tube furnace by passing argon gas through the internal tubing for 20 minutes. Increase the temperature to 400°C at a rate of 10°C / min and hold for 2 hours. Then cool to room temperature and remove.

[0096] Step 8: Simply grind the solid obtained in Step 7, wash it three times each with water and ethanol, and then put it into a vacuum drying oven to dry for 24 hours;

[0097] Step 9: Grind the dried material obtained in Step 8 into powder to obtain boron-doped carbon-based iron single-atom material (Fe-N). x B / GCN8).

[0098] In Example 5, the amount of boric acid used was 120 mg. Therefore, the boron-doped carbon-based iron single-atom material prepared in this example is labeled as Fe-N. x B / GCN12.

[0099] Application Example 1: Scanning Electron Microscopy Testing

[0100] The carbon-based iron single-atom material (Fe-N) prepared in Example 1 was tested respectively. x / GCN) and the boron-doped carbon-based iron single-atom material (Fe-N) obtained in Example 5 x B / GCN12) was subjected to scanning electron microscopy testing, and the test results are as follows: Figure 1a andFigure 1b As shown.

[0101] from Figure 1a and Figure 1b As can be seen from Examples 1 and 4, the materials (Fe-N) obtained are... x / GCN and Fe-N x B / GCN12) retains the highly crystalline fibrous lamellar structure of chitin. After two-step calcination, it exhibits a layered stacked structure, and the introduction of boric acid in Example 5 does not destroy this structure.

[0102] Application Example 2: Transmission Electron Microscopy Testing

[0103] The carbon-based iron single-atom material (Fe-N) prepared in Example 1 was tested respectively. x / GCN) and the boron-doped carbon-based iron single-atom material (Fe-N) obtained in Example 5 x Transmission electron microscopy was performed on B / GCN12, and the test results are as follows: Figure 2a and Figure 2b As shown.

[0104] from Figure 2a , Figure 2b It can be seen that the materials (Fe-N) prepared in Examples 1 and 5 x / GCN and Fe-N x B / GCN12) is a two-dimensional layered nanosheet structure.

[0105] Application Example 3: High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy Test

[0106] The boron-doped carbon-based iron single-atom material (Fe-N) obtained in Example 5 x High-angle annular dark-field scanning transmission electron microscopy (TEM) tests were performed on B / GCN12. The test results are as follows: Figure 3 As shown.

[0107] from Figure 3 It can be seen that the material (Fe-N) prepared in Example 5 x The presence of numerous individual bright spots in B / GCN12 indicates that Fe exists as individual, isolated atoms.

[0108] Application Example 4: X-ray Diffraction Test Experiment

[0109] The carbon-based iron single-atom material (Fe-N) prepared in Example 1 was tested respectively. x / GCN) and the boron-doped carbon-based iron single-atom material (Fe-N) obtained in Example 5 x X-ray diffraction tests were performed on B / GCN12, and the results are as follows: Figure 4 As shown.

[0110] from Figure 4 As can be seen from the above, the materials (Fe-N) prepared in Examples 1 and 5... x / GCN and Fe-N x Both B / GCN12 and B / GCN12 belong to the typical hexagonal graphitic carbon structure.

[0111] Application Example 5: X-ray photoelectron spectroscopy test

[0112] The carbon-based iron single-atom material (Fe-N) prepared in Example 1 was tested respectively. x / GCN) and the boron-doped carbon-based iron single-atom material (Fe-N) obtained in Example 5 x X-ray photoelectron spectroscopy (XPS) was performed on B / GCN12, and the results are shown in Figure 5.

[0113] Figure 5a Carbon-based iron single-atom materials (Fe-N) x / GCN) and boron-doped carbon-based iron single-atom materials (Fe-N) x The binding energies of pyridine nitrogen, pyrrole nitrogen, graphitic nitrogen, and nitrogen oxides were observed in both B / GCN12, indicating that nitrogen was successfully doped in a self-doping manner. In addition, the N1s spectra of both showed peaks of nitrogen-coordinated iron formed by the hybridization of Fe orbitals with N axial ligands, which also indicates that iron is distributed in an individual atom manner. Figure 5b Boron-doped carbon-based iron single-atom materials (Fe-N) x The presence of CBN bonds was detected in the B1s spectrum of B / GCN12, indicating that boron atoms were successfully doped into carbon-based iron single-atom materials.

[0114] Application Example 6: Electrochemical Experiment

[0115] The carbon-based iron single-atom material (Fe-N) prepared in Example 1 was tested respectively. x / GCN) and the boron-doped carbon-based iron single-atom material (Fe-N) obtained in Example 5 x B / GCN12 was placed in a 5% Nafion solution diluted 10 times with water. Then, the mixture was sonicated for 5 minutes to ensure uniform dispersion in the solution. The suspension was immediately drop-coated onto the surface of a glassy carbon electrode. After the material on the glassy carbon electrode surface dried, electrochemical impedance spectroscopy, Tafel curves, and open-circuit voltage were measured in a three-electrode electrolytic cell using 0.2 M Na2SO4 as the electrolyte. The test results are as follows: Figure 6 As shown.

[0116] from Figure 6 As can be seen in Figure (a), boron-doped carbon-based iron single-atom materials (Fe-N) x B / GCN12) is more efficient than carbon-based iron single-atom materials (Fe-N).x The smaller radius of curvature of the GCN ( / GCN) indicates that collision doping gives carbon-based iron single-atom materials lower resistance, thereby accelerating the electron transfer rate in catalytic reactions. Figure 6 In Figure (b), boron-doped carbon-based iron single-atom material (Fe-N) x B / GCN12) is more efficient than carbon-based iron single-atom materials (Fe-N). x / GCN) has a more negative free corrosion potential, indicating that Fe-N x B / GCN12 has strong redox properties. Figure 6 In Figure (c), PMS solution was added after the open-circuit voltage stabilized, i.e., at a test time of 50 s. Boron-doped carbon-based iron single-atom material (Fe-N) x B / GCN12) is more efficient than carbon-based iron single-atom materials (Fe-N). x The larger voltage change ( / GCN) indicates that boron doping enhances the reactivity between carbon-based iron single-atom materials and PMS.

[0117] Application Example 7: Sulfamethoxazole Removal Experiment

[0118] Take 20 mg of the material (Fe-N) prepared in Examples 1 to 5 respectively. x / GCN,Fe-N x B / GCN4, Fe-N x B / GCN6,Fe-N x B / GCN8 and Fe-N x B / GCN12) was placed in 50 mL of 5 mg / L sulfamethoxazole solution. Immediately, sonication was performed for 60 seconds. Then, 1 mM PMS reagent was added using a pipette, and timing was started. At pre-set time intervals, 1.5 mL of the reaction solution was drawn using a 5 mL syringe and filtered through a microporous filter into a brown liquid chromatography vial containing 50.0 μL of Na2S2O3·5H2O (0.6 M) solution to terminate the reaction. Further analysis was performed using liquid chromatography. The concentration change of sulfamethoxazole during the entire catalytic reaction is shown in the figure. Figure 7 .

[0119] from Figure 7 It can be seen that, without the addition of a catalyst, pure PMS has a very limited ability to degrade sulfamethoxazole. Although carbon-based iron single-atom materials (Fe-N...) x The addition of GCN effectively improved the removal capacity of sulfamethoxazole in the reaction system, but the degradation efficiency per unit time gradually slowed down. Boron doping significantly improved the catalytic performance of the material. Boron-doped carbon-based iron single-atom materials (Fe-N...) xB / GCN12 can completely remove sulfamethoxazole from the system within 50 minutes, fully demonstrating the advantages and practical application potential of this material in the treatment of sulfamethoxazole pollution.

[0120] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing boron-doped carbon-based iron single-atom materials through a two-step calcination process, characterized in that, Includes the following steps: Step 1: Place the carbon-based reagent, iron reagent, and soft template into anhydrous ethanol respectively; the soft template includes polyether F127; the carbon-based reagent includes chitosan; Step 2: Sonicate the carbon-based reagent solution, iron reagent solution and soft template solution obtained in Step 1, and then heat them separately in an oil bath to 55-70°C; Step 3: Add the heated iron reagent solution and soft template solution to the heated carbon-based reagent solution, wait for the ethanol to evaporate to dryness, and then place it in an oven to dry. Step 4: After simply grinding the material obtained in Step 3, place it in a quartz boat. Pass argon gas through the internal pipes of the tube furnace for 10-30 minutes to purge all the air from the pipes. Raise the temperature to 800-850°C at a rate of 9-10°C / min and maintain it for 2-2.5 hours. Then cool it to room temperature and remove it. Step 5: Grind the solid obtained in Step 4, wash it with water and ethanol 3-4 times each, and then put it into a vacuum drying oven to dry for 16-36 hours; Step 6: Grind the dried material obtained in Step 5 into powder; take 350-450 mg of powder, then add 40-120 mg of boric acid and grind and mix thoroughly. Step 7: Place the mixture obtained in Step 6 into a quartz boat, and purge the internal tubing of the tube furnace with argon gas for 10-30 minutes to purge all air from the tubing; raise the temperature to 400-450°C at a rate of 9-10°C / min and hold for 2-2.5 hours, then cool to room temperature and remove. Step 8: Grind the solid obtained in Step 7, wash it with water and ethanol respectively, and then put it into a vacuum drying oven to dry for 16-36 hours; Step 9: Grind the dried material obtained in Step 8 into powder to obtain boron-doped carbon-based iron single-atom material.

2. The method for preparing boron-doped carbon-based iron single-atom materials according to claim 1, characterized in that, The iron reagent includes ferric chloride hexahydrate; the method used is a soft template + two-step calcination strategy.

3. The method for preparing boron-doped carbon-based iron single-atom materials according to claim 1, characterized in that, In step two, the ultrasound session lasts for 20-30 minutes.

4. The method for preparing boron-doped carbon-based iron single-atom materials according to claim 1, characterized in that, In step three, the drying temperature in the oven is 50–70°C.

5. A boron-doped carbon-based iron single-atom material prepared by any one of claims 1-4.

6. The application of the boron-doped carbon-based iron single-atom material according to claim 5, characterized in that, The boron-doped carbon-based iron single-atom material is used for the efficient degradation of sulfamethoxazole.

7. The application according to claim 6, characterized in that, Includes the following steps: (1) Mix sulfamethoxazole with water to obtain a sulfamethoxazole contaminated solution; (2) The boron-doped carbon-based iron single-atom material is placed into the sulfamethoxazole contaminated solution obtained in step (1) and stirred. (3) Add potassium persulfate PMS reagent.

8. The application according to claim 7, characterized in that, The concentration of sulfamethoxazole in the sulfamethoxazole-contaminated solution described in step (1) is 3-5 mg / L.

9. The application according to claim 7, characterized in that, The amount of boron-doped carbon-based iron single-atom material added in step (2) is 0.3 to 0.45 g / L.

10. The application according to claim 7, characterized in that, The amount of PMS reagent added in step (3) is 0.6 to 1.2 mM.

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