Carbon material co-doped with iron carbide and nitrogen-coordinated iron and nitrogen and graphene, and preparation method and application thereof

Abstract

The present application relates to a kind of carbonized iron and nitrogen coordination iron co-doped nitrogen and graphene carbon material and preparation method and application, with six hydrated ferric chloride as iron source, with chitin as nitrogen, carbon source. By simple one-step method, after mixing, calcination, grinding way, carbonized iron and nitrogen coordination iron co-doped nitrogen and graphene carbon material is synthesized.The material prepared by the present application presents two-dimensional layered structure, after adding potassium hydrogen peroxodisulfate oxidant, the material can completely remove the active pharmaceutical ingredient naphthyl in water in a short time.Naproxen.The synthesis method proposed in the present application is simple and easy to operate, and the material performance is excellent, which can provide a new design idea for nitrogen coordination iron nanomaterial supported by carbon material, and be applied to the remediation of contaminated water.

Description

Technical Field

[0001] This invention belongs to the field of functional nanomaterials and technology, specifically a carbon material co-doped with iron carbide and nitrogen-coordinated iron containing nitrogen and graphene, as well as its preparation method and application. Background Technology

[0002] With the continuous development of nanomaterials technology, its application in the field of environmental functional materials has attracted widespread attention from scholars. Among them, graphene, due to its excellent electrical and thermal conductivity, high electron mobility, and good stability, has been widely used in environmental pollution control, and there are already examples of site remediation. However, using graphene alone for remediation has problems such as high cost and limited catalytic activity leading to a slow remediation process.

[0003] In recent years, graphene materials doped with heteroatoms (including S, N, P, and other metals) have been widely used because they can effectively break the spline structure of graphene. 2 The structure allows electrons on the carbon plane to easily delocalize, resulting in many excellent properties, such as stronger conductivity and better catalytic performance. Compared with non-metallic element doping, metallic elements often have better catalytic activity. Co-doping of metallic and non-metallic elements may form a metallic element structure with extremely high activity of non-metallic element coordination, but this structure has obvious stability defects.

[0004] Patent CN116914163A discloses an Fe-NC catalyst, its preparation method, and its applications. This catalyst utilizes hydrotalcite as a template to construct a graphene-like two-dimensional sheet-like carbon nanomaterial, but the raw material, heme, is extremely expensive. Addressing the problems of the aforementioned patent, and to further improve the stability and catalytic activity of the metal element structure coordinated with non-metallic elements, this paper proposes developing a novel carbon material with excellent stability and catalytic activity using inexpensive chitin, which possesses a natural and unique three-dimensional network structure. This is of great significance for solving the problems of high graphene consumption and severe environmental pollution, as well as promoting the rational application of such materials in environmental governance. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a carbon material co-doped with nitrogen and graphene by iron carbide and nitrogen-coordinated iron, as well as its preparation method and application.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing nitrogen-containing and graphene-containing carbon materials co-doped with iron carbide and nitrogen-coordinated iron, comprising the following steps:

[0008] Step 1: Place the chitosan in an agate mortar and grind it briefly until it becomes powder.

[0009] Step 2: Place ferric chloride hexahydrate into an agate mortar containing chitin;

[0010] Step 3: Grind and mix the substances from Step 1 and Step 2 thoroughly;

[0011] Step 4: Place the mixture obtained from grinding in Step 3 into a quartz boat, and purge the internal pipes of the tube furnace with nitrogen for 20 minutes to purge all air from the pipes;

[0012] Step 5: Calcine the material in a tube furnace, then cool it to room temperature and remove it.

[0013] Step 6: Simply grind the solid obtained in Step 5, and then wash it three times each with water and ethanol;

[0014] Step 7: Place the material obtained in Step 6 into a vacuum drying oven to dry.

[0015] Step 8: Grind the dried material prepared in Step 7 into a uniform powder to obtain a carbon material co-doped with nitrogen and graphene by iron carbide and nitrogen-coordinated iron.

[0016] Furthermore, the trivalent iron salt mentioned in step two includes either ferric chloride hexahydrate or ferric nitrate nonahydrate.

[0017] Furthermore, the mass ratio of ferric salt to chitin is 0.0005 to 0.01:1.

[0018] Furthermore, in step five, the calcination process involves heating the temperature to 750–850°C at a rate of 4–5°C / min and maintaining it for 1.5–2.5 hours.

[0019] Furthermore, in step seven, the vacuum drying temperature is 30℃~80℃, and the time is 16~32h.

[0020] Secondly, the present invention provides a carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron prepared by the above method.

[0021] Thirdly, the present invention provides an application of a carbon material co-doped with iron carbide and nitrogen-coordinated iron containing nitrogen and graphene, wherein the carbon material co-doped with iron carbide and nitrogen-coordinated iron containing nitrogen and graphene can be used for the efficient degradation of naproxen.

[0022] This application includes the following steps:

[0023] (1) Dissolve naproxen in a beaker and dilute to volume in a volumetric flask to obtain a naproxen contaminated solution;

[0024] (2) The carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron is placed into the conical flask containing naproxen contaminant in step (1) and magnetically stirred for 5 to 30 minutes.

[0025] (3) Add potassium persulfate (PMS) reagent to the conical flask containing the carbon material and pollutants in step (2), and continue to stir magnetically for 12-15 minutes. The remaining concentration of naproxen reflects the degradation effect of the carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron.

[0026] Furthermore, the concentration of naproxen in the naproxen-contaminated solution described in step (1) is 5–10 mg / L.

[0027] Furthermore, in step (2), the amount of carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron is 0.1 to 0.25 g / L.

[0028] Furthermore, the amount of PMS reagent added in step (3) is 0.1 to 0.8 mM.

[0029] This invention uses ferric chloride hexahydrate as the iron source and chitin as the nitrogen and carbon source, employing a post-trivalent iron-nitrogen coordination strategy to synthesize a nitrogen- and graphene-co-doped carbon material containing nitrogen and graphene through a simple one-step method. This material exhibits a two-dimensional layered structure. The method of this invention has the following advantages: First, the self-doping of chitin with nitrogen not only eliminates the need for an additional nitrogen source but also effectively improves the conductivity and catalytic performance of the graphene material. Second, chitin, with its natural and unique three-dimensional network structure, provides a favorable environment for subsequent metal coordination. Furthermore, the simultaneously generated iron carbide improves the stability and catalytic activity of the nitrogen-co-doped iron, demonstrating the three-in-one design principle. This invention provides a new construction approach and technical method reference for similar co-doped nanomaterials.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] (1) The present invention uses a one-step method to prepare carbon materials containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron, which is simple and easy to operate.

[0032] (2) The present invention uses chitin, which has a natural and special three-dimensional network structure, as raw material. It can not only achieve nitrogen self-doping without the need for an additional nitrogen source, but also provide an excellent environment for the coordination of iron.

[0033] (3) The method of the present invention can simultaneously achieve the doping of iron carbide, nitrogen-coordinated iron and nitrogen.

[0034] (4) The method of the present invention will not cause iron pollution due to the introduction of iron salts.

[0035] (5) The material prepared by the present invention has excellent catalytic performance of nitrogen-coordinated iron, and its stability is also improved.

[0036] (6) The material prepared by the present invention can efficiently remove naproxen from water and can completely degrade naproxen (removal rate 100%) in a short time (12-15 min), which has application prospects in the field of sewage treatment. Attached Figure Description

[0037] Figure 1 (a) and (b) are scanning electron microscope images of nitrogen-containing carbon materials with graphene and iron carbide co-doped with nitrogen-containing carbon materials with graphene, respectively.

[0038] Figure 2 (a) and (b) in the image are transmission electron microscope images of nitrogen-containing carbon materials with graphene and iron carbide co-doped with nitrogen-coordinated iron, respectively. Figure 2 (c) and (d) are high-resolution transmission electron microscope images of nitrogen-containing carbon materials with graphene and iron carbide and nitrogen-coordinated iron co-doped nitrogen-containing carbon materials with graphene, respectively.

[0039] Figure 3 X-ray diffraction patterns of nitrogen-containing carbon materials with graphene, and nitrogen-coordinated iron co-doped nitrogen-containing carbon materials with graphene.

[0040] Figure 4 In the image (a), we see the N1s high-resolution XPS spectra of nitrogen-containing carbon materials with graphene and iron carbide and nitrogen-coordinated iron co-doped nitrogen-containing carbon materials with graphene. Figure 4 (b) is the high-resolution XPS spectrum of Fe 2p in nitrogen-coordinated iron co-doped carbon material containing nitrogen and graphene.

[0041] Figure 5 (a), (b), and (c) in the figure are respectively the cyclic voltammetry, electrochemical impedance spectroscopy, and tafeline curves of nitrogen-containing carbon materials with graphene and iron carbide and nitrogen-coordinated iron co-doped nitrogen-containing carbon materials with graphene.

[0042] Figure 6 This is a graph showing the trend of naproxen concentration in the reaction system over time. Detailed Implementation

[0043] 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.

[0044] 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.

[0045] Comparative Example 1: Preparation of a nitrogen-containing carbon material (GCN) with graphene

[0046] Step 1: Place 10g of chitosan in an agate mortar and grind it briefly until it becomes powder.

[0047] Step 2: Place the ground material obtained in Step 1 into a quartz boat, and purge the internal pipes of the tube furnace with nitrogen for 20 minutes to remove all air from the pipes.

[0048] Step 3: Increase the temperature to 800℃ at a rate of 5℃ / min and hold for 2 hours, then cool to room temperature and remove.

[0049] Step 4: Simply grind the solid obtained in Step 3, and then wash it three times each with water and ethanol;

[0050] Step 5: Place the material obtained in Step 4 into a vacuum drying oven and dry for 24 hours.

[0051] Step 6: Grind the dried material obtained in Step 5 into powder to obtain a carbon material containing nitrogen and graphene, labeled as GCN.

[0052] Example 1: A carbon material co-doped with iron carbide and nitrogen-coordinated iron containing nitrogen and graphene (Fe3C / Fe-N) x Preparation of @GCN5

[0053] Step 1: Place 10g of chitosan in an agate mortar and grind it briefly until it becomes powder.

[0054] Step 2: Place 5mg of ferric chloride hexahydrate into an agate mortar containing chitin;

[0055] Step 3: Grind and mix the substances from Step 1 and Step 2 thoroughly;

[0056] Step 4: Place the mixture obtained in Step 3 into a quartz boat, and purge the internal pipes of the tube furnace with nitrogen for 20 minutes to purge all air from the pipes;

[0057] Step 5: Increase the temperature to 800℃ at a rate of 5℃ / min and hold for 2 hours, then cool to room temperature and remove.

[0058] Step 6: Simply grind the solid obtained in Step 5, and then wash it three times each with water and ethanol;

[0059] Step 7: Place the material obtained in Step 6 into a vacuum drying oven and dry for 24 hours.

[0060] Step 8: Grind the dried material prepared in Step 7 into powder to obtain a carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron.

[0061] In this embodiment, the amount of ferric chloride hexahydrate used was 5 mg. Therefore, the carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron prepared in this embodiment was labeled as Fe3C / Fe-N. x @GCN5.

[0062] Example 2: A carbon (Fe3C / Fe-N) co-doped with nitrogen and graphene containing iron carbide and nitrogen-coordinated iron. x Preparation of @GCN25 material

[0063] Step 1: Place 10g of chitosan in an agate mortar and grind it briefly until it becomes powder.

[0064] Step 2: Place 25mg of ferric chloride hexahydrate into an agate mortar containing chitin;

[0065] Step 3: Grind and mix the substances from Step 1 and Step 2 thoroughly;

[0066] Step 4: Place the mixture obtained in Step 3 into a quartz boat, and purge the internal pipes of the tube furnace with nitrogen for 20 minutes to purge all air from the pipes;

[0067] Step 5: Increase the temperature to 800℃ at a rate of 5℃ / min and hold for 2 hours, then cool to room temperature and remove.

[0068] Step 6: Simply grind the solid obtained in Step 5, and then wash it three times each with water and ethanol;

[0069] Step 7: Place the material obtained in Step 6 into a vacuum drying oven and dry for 24 hours.

[0070] Step 8: Grind the dried material prepared in Step 7 into powder to obtain a carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron.

[0071] In this embodiment, the amount of ferric chloride hexahydrate used was 25 mg. Therefore, the nitrogen- and graphene-co-doped carbon material containing nitrogen and nitrogen-coordinated iron prepared in this embodiment was labeled as Fe3C / Fe-N.x @GCN25.

[0072] Example 3: A carbon (Fe3C / Fe-N) co-doped with nitrogen and graphene containing iron carbide and nitrogen-coordinated iron. x Preparation of @GCN50 materials

[0073] Step 1: Place 10g of chitosan in an agate mortar and grind it briefly until it becomes powder.

[0074] Step 2: Place 50mg of ferric chloride hexahydrate into an agate mortar containing chitin;

[0075] Step 3: Grind and mix the substances from Step 1 and Step 2 thoroughly;

[0076] Step 4: Place the mixture obtained in Step 3 into a quartz boat, and purge the internal pipes of the tube furnace with nitrogen for 20 minutes to purge all air from the pipes;

[0077] Step 5: Increase the temperature to 800℃ at a rate of 5℃ / min and hold for 2 hours, then cool to room temperature and remove.

[0078] Step 6: Simply grind the solid obtained in Step 5, and then wash it three times each with water and ethanol;

[0079] Step 7: Place the material obtained in Step 6 into a vacuum drying oven and dry for 24 hours.

[0080] Step 8: Grind the dried material prepared in Step 7 into powder to obtain a carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron.

[0081] In this embodiment, the amount of ferric chloride hexahydrate used was 50 mg. Therefore, the nitrogen- and graphene-co-doped carbon material containing nitrogen and nitrogen-coordinated iron prepared in this embodiment was labeled as Fe3C / Fe-N. x @GCN50.

[0082] Example 4: A carbon (Fe3C / Fe-N) co-doped with nitrogen and graphene containing iron carbide and nitrogen-coordinated iron. x Preparation of @GCN100 materials

[0083] Step 1: Place 10g of chitosan in an agate mortar and grind it briefly until it becomes powder.

[0084] Step 2: Place 100mg of ferric chloride hexahydrate into an agate mortar containing chitin;

[0085] Step 3: Grind and mix the substances from Step 1 and Step 2 thoroughly;

[0086] Step 4: Place the mixture obtained in Step 3 into a quartz boat, and purge the internal pipes of the tube furnace with nitrogen for 20 minutes to purge all air from the pipes;

[0087] Step 5: Increase the temperature to 800℃ at a rate of 5℃ / min and hold for 2 hours, then cool to room temperature and remove.

[0088] Step 6: Simply grind the solid obtained in Step 5, and then wash it three times each with water and ethanol;

[0089] Step 7: Place the material obtained in Step 6 into a vacuum drying oven and dry for 24 hours.

[0090] Step 8: Grind the dried material prepared in Step 7 into powder to obtain a carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron.

[0091] In this embodiment, the amount of ferric chloride hexahydrate used was 100 mg. Therefore, the nitrogen- and graphene-co-doped carbon material containing nitrogen and nitrogen-coordinated iron prepared in this embodiment was labeled as Fe3C / Fe-N. x @GCN100.

[0092] Performance Tests and Results

[0093] 1. Scanning electron microscope test

[0094] The nitrogen-containing carbon (GCN) material with graphene prepared in Comparative Example 1 and the nitrogen-coated carbon material with graphene (Fe3C / Fe-N) co-doped with iron carbide and nitrogen-coordinated iron prepared in Example 3 were compared respectively. x The @GCN50 was tested using a scanning electron microscope, and the test results are as follows: Figure 1 As shown in (a) and (b) in the figure.

[0095] from Figure 1 As can be seen from (a) and (b) in Comparative Example 1 and Example 3, the materials (GCN and Fe3C / Fe-N) prepared are... x Both @GCN50 and GCN50 exhibit a two-dimensional layered structure. However, the material prepared in Example 3 has some iron carbide nanoparticles uniformly distributed on its surface.

[0096] 2. Transmission electron microscopy test

[0097] The nitrogen-containing carbon (GCN) material with graphene prepared in Comparative Example 1 and the nitrogen-coated carbon material with graphene (Fe3C / Fe-N) co-doped with iron carbide and nitrogen-coordinated iron prepared in Example 3 were compared respectively. x The @GCN50 was tested using a transmission electron microscope, and the test results are as follows: Figure 2As shown in (a) and (b) in the figure. Comparative Example 1 shows the nitrogen-containing carbon (GCN) material with graphene and nitrogen co-doped with iron carbide and nitrogen-coordinated iron obtained in Example 3 (Fe3C / Fe-N). x High-resolution transmission electron microscopy (TEM) images of the GCN50 are shown below. Figure 2 As shown in (c) and (d) in the figure.

[0098] from Figure 2 (a) in the middle, Figure 2 As can be seen in (b) of Comparative Example 1 and Example 3, the materials (GCN and Fe3C / Fe-N) prepared are... x @GCN50) are all two-dimensional layered nanosheet structures, and Figure 2 (c) in the middle Figure 2 In (d), distorted graphene lattice fringes appeared, indicating the presence of graphene. Additionally, the material (Fe3C / Fe-N) prepared in Example 3... x Typical lattice fringes of iron carbide were also observed in the @GCN50, indicating the presence of iron carbide.

[0099] 3. X-ray diffraction test experiment

[0100] The nitrogen-containing carbon (GCN) material with graphene prepared in Comparative Example 1 and the nitrogen-coated carbon material with graphene (Fe3C / Fe-N) co-doped with iron carbide and nitrogen-coordinated iron prepared in Example 3 were compared respectively. x X-ray diffraction testing was performed using the @GCN50, and the results are as follows: Figure 3 As shown.

[0101] from Figure 3 As can be seen from the above, the materials (GCN and Fe3C / Fe-N) prepared in Comparative Example 1 and Example 3... x All GCN50 diffraction materials retain a graphitic carbon structure. Furthermore, compared to nitrogen- and graphene-containing carbon materials, the co-doped carbon materials containing nitrogen and graphene with iron carbide and nitrogen-coordinated iron exhibit a stronger degree of graphitization, indicating that the introduction of iron can effectively enhance the graphitization degree of the material. Additionally, the weak diffraction peak near 42.8° is that of iron carbide, further confirming its presence.

[0102] 4. X-ray photoelectron spectroscopy test

[0103] The nitrogen-containing carbon (GCN) material with graphene prepared in Comparative Example 1 and the nitrogen-coated carbon material with graphene (Fe3C / Fe-N) co-doped with iron carbide and nitrogen-coordinated iron prepared in Example 3 were compared respectively. x @GCN50) was subjected to X-ray photoelectron spectroscopy testing, and the test results are as follows: Figure 4 As shown.

[0104] Figure 4 Image (a) shows nitrogen-containing carbon (GCN) materials with graphene and nitrogen-coordinated iron co-doped nitrogen-containing carbon materials with graphene (Fe3C / Fe-N). x The binding energies for pyridine nitrogen, pyrrole nitrogen, graphitic nitrogen, and nitrogen oxides were observed in all GCN50 samples, indicating that nitrogen was successfully doped via self-doping. Figure 4 Compared to the N1s spectra of nitrogen-containing carbon (GCN) materials with graphene (a), iron carbide and nitrogen-coordinated iron co-doped nitrogen-containing carbon materials with graphene (Fe3C / Fe-N) are shown in (a). x The presence of nitrogen-coordinated iron (@GCN50) indicates the existence of nitrogen-coordinated iron, which is formed by the orbital hybridization of N axial ligands and Fe. Figure 4 (b) shows that iron carbide and nitrogen-coordinated iron are co-doped with nitrogen-containing graphene carbon materials (Fe3C / Fe-N). x Fe 2p spectrum of @GCN50 2+ 2p 3 / 2 It belongs to nitrogen-coordinated iron, and the binding energy of Fe3C was also detected, which further indicates that iron carbide and nitrogen-coordinated iron have been successfully co-doped.

[0105] 5. Electrochemical Experiments

[0106] The nitrogen-containing carbon and graphene-containing carbon (GCN) material prepared in Comparative Example 1 and the iron carbide and nitrogen-coordinated iron co-doped nitrogen-containing carbon material (Fe3C / Fe-N) obtained in Example 3 were compared respectively. x @GCN50 was placed in a mixed solution containing 60 μL of 5% Nafion and 540 μL of water, and sonicated for 5 min to obtain a homogeneous suspension. The suspension was then drop-coated onto the surface of a glassy carbon electrode. After natural drying, cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel curves were performed in a three-electrode electrolytic cell using 0.2 M Na2SO4 as the electrolyte. The test results are as follows: Figure 5 As shown.

[0107] from Figure 5 As can be seen in (a), iron carbide and nitrogen-coordinated iron are co-doped with nitrogen-containing graphene carbon materials (Fe3C / Fe-N). x @GCN50 has a larger cyclic voltammetric area than nitrogen-containing carbon (GCN) materials with graphene, indicating that Fe3C / Fe-N x @GCN50 has a stronger ability to store and transfer electrons. Figure 5 In (b), iron carbide and nitrogen-coordinated iron are co-doped with nitrogen-containing carbon materials containing graphene (Fe3C / Fe-N). x@GCN50 has a smaller radius of curvature than nitrogen-containing graphene-coated carbon (GCN) materials, indicating that nitrogen-containing graphene-coated carbon has lower electrical resistance after being doped with iron carbide and nitrogen-coordinated iron, which is beneficial to the electron transport process. Figure 5 In (c), iron carbide and nitrogen-coordinated iron are co-doped with nitrogen-containing carbon materials containing graphene (Fe3C / Fe-N). x @GCN50) exhibits a lower free corrosion potential than nitrogen-containing carbon (GCN) materials with graphene, indicating that Fe3C / Fe-N x @GCN50 has stronger redox capabilities.

[0108] Application Example 6: Naproxen Removal Experiment

[0109] Take 10 mg of each of the materials (GCN, Fe3C / Fe-N) prepared in Comparative Example 1 and Examples 1 to 4 respectively. x @GCN5, Fe3C / Fe-N x @GCN25, Fe3C / Fe-N x @GCN50 and Fe3C / Fe-N x The reagent (@GCN100) was placed in 50 mL of 10 mg / L naproxen solution. The mixture was sonicated for 60 s, then stirred for 30 min to establish adsorption-desorption equilibrium. Subsequently, 0.4 mM PMS reagent was added, and 1.5 mL of the reaction solution was extracted using a syringe at predetermined time intervals. The solution was then filtered through a 0.22 μm microfiltration filter into a brown reagent bottle containing 50.0 μL of 0.6 M Na2S2O3·5H2O solution to terminate the reaction. Further analysis was performed using liquid chromatography. A pure PMS solution without any catalyst was used as a blank control group. The concentration changes of naproxen during the reaction were shown in the figure. Figure 6 As shown.

[0110] from Figure 6 It can be seen that, in the absence of any catalyst, PMS alone has a very limited ability to degrade naproxen. The concentration of naproxen is significantly higher in nitrogen- and graphene-co-doped carbon materials (Fe3C / Fe-N) with iron carbide and nitrogen-coordinated iron. x In the reaction system of @GCN), the temperature drops very rapidly, sometimes completely within 12 minutes. This contrasts sharply with pure nitrogen-containing carbon and graphene, fully demonstrating the advantages and practical application potential of co-doping with iron carbide and nitrogen-coordinated iron in the treatment of naproxen pollution. Figure 6 It can also be seen that with the increase of iron ion concentration, the degradation rate of naproxen by nitrogen- and graphene-co-doped carbon materials containing iron carbide and nitrogen-coordinated iron accelerates. (Fe3C / Fe-N) x@GCN100 is the best choice because iron ions initially coordinate with nitrogen on the carbon material. Excess iron will appear in the form of iron carbide, and together with nitrogen-coordinated iron, it will enhance the catalyst's activity against PMS, thereby promoting the degradation of naproxen by free radicals or non-free radicals.

[0111] 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 a nitrogen- and graphene-containing carbon material co-doped with iron carbide and nitrogen-coordinated iron, characterized in that, Includes the following steps: Step 1: Place the chitosan in an agate mortar and grind it into powder; Step 2: Place ferric chloride hexahydrate into an agate mortar containing chitin; the mass ratio of ferric chloride hexahydrate to chitin is 0.0005 to 0.01:

1. Step 3: Grind and mix the substances from Step 1 and Step 2 thoroughly; Step 4: Place the mixture obtained from grinding in Step 3 into a quartz boat, and purge all air from the tube furnace by introducing nitrogen gas into the internal pipes. Step 5: Calcine the material in a tube furnace, then cool it to room temperature and remove it. Step Six: Simply grind the solid obtained in Step Five, and then wash it with water and ethanol; Step 7: Place the material obtained in Step 6 into a vacuum drying oven to dry; Step 8: Grind the dried material prepared in Step 7 into a uniform powder to obtain a carbon material co-doped with nitrogen and graphene by iron carbide and nitrogen-coordinated iron.

2. The method for preparing nitrogen-containing and graphene-co-doped carbon materials using iron carbide and nitrogen-coordinated iron according to claim 1, characterized in that, In step five, the calcination process involves heating the temperature to 750–850°C at a rate of 4–5°C / min and holding it for 1.5–2.5 hours.

3. The method for preparing nitrogen-containing and graphene-co-doped carbon materials using iron carbide and nitrogen-coordinated iron according to claim 1, characterized in that, In step seven, the vacuum drying temperature is 30℃~80℃, and the time is 16~32h.

4. A carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron, prepared by the preparation method according to any one of claims 1-3.

5. The application of a nitrogen- and graphene-containing carbon material co-doped with iron carbide and nitrogen-coordinated iron as described in claim 4, characterized in that, The iron carbide and nitrogen-coordinated iron co-doped nitrogen-containing and graphene-containing carbon materials are used for the degradation of naproxen.

6. The application according to claim 5, characterized in that, Includes the following steps: (1) Dissolve naproxen in a beaker and dilute to volume in a volumetric flask to obtain a naproxen contaminated solution; (2) The carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron is placed into the conical flask containing naproxen contaminant in step (1) and magnetically stirred. (3) Add potassium persulfate (PMS) reagent to the conical flask containing the carbon material and pollutants in step (2), and continue to stir magnetically. The remaining concentration of naproxen reflects the degradation effect of the carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron.

7. The application according to claim 6, characterized in that, The concentration of naproxen in the naproxen contaminated solution in step (1) is 5-10 mg / L; the amount of carbon material containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron in step (2) is 0.1-0.25 g / L.

8. The application according to claim 6, characterized in that, The amount of PMS reagent added in step (3) is 0.1 to 0.8 mM.

9. The application according to claim 6, characterized in that, The carbon materials containing nitrogen and graphene co-doped with iron carbide and nitrogen-coordinated iron can completely degrade naproxen within 12 to 15 minutes.

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