Method for preparing magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material by one-step method and application thereof

Abstract

The invention relates to a method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material by a one-step method and an application of the magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material, and aims to solve the problems of poor catalytic activity, complex separation and recovery and complex synthesis method of the existing PMS activated catalytic material. According to the method, melamine is selected as a carbon source and a nitrogen source, ferric nitrate and copper sulfate are selected as an iron source and a copper source respectively, and the magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material is synthesized in one step by adopting a high-temperature pyrolysis method. The adsorbent not only has excellent adsorption performance on dye-methylene blue, but also can realize high-efficiency oxidative degradation. The magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material prepared by the invention not only has excellent catalytic performance, but also is easy to magnetically separate and recycle, and is suitable for efficient treatment of dye wastewater. The method is applied to the field of catalytic degradation of wastewater.

Description

Technical Field

[0001] The invention relates to a one-step preparation method for a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material and application thereof. Background Art

[0002] Since high-concentration dye wastewater is discharged into the water environment, it poses a serious threat to the ecological environment and human health. Therefore, it is urgent to treat the dye wastewater before discharge.

[0003] Advanced oxidation technology based on sulfate radicals uses cheap and relatively stable peroxymonosulfate (PMS) to generate sulfate radicals (SO4· - ) and other strong oxidizing species, and SO4· - Compared to hydroxyl radicals (·OH), PMS has attracted extensive attention due to its longer lifetime (30-40 µs vs 20 ns). In order to improve the utilization efficiency of PMS, it is necessary to develop catalysts with high catalytic activity.

[0004] Traditional PMS-activated catalytic materials have disadvantages such as low catalytic activity and difficulty in separation and recovery. In addition, the catalyst preparation process is relatively complex and time-consuming. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems of poor catalytic activity, complex separation and recovery, and complex synthesis methods of existing PMS activated catalytic materials, and to provide a one-step method for preparing magnetic Fe3O4 / Cu / nitrogen-doped carbon composite materials.

[0006] The one-step method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material of the present invention is carried out according to the following steps:

[0007] Melamine, ferric nitrate, and copper sulfate were placed in a mortar and ground until completely mixed to obtain a mixed sample. The mixed sample was then placed in a porcelain boat and transferred to a tube furnace for pyrolysis at 650-850°C under protective gas and then cooled to room temperature to obtain a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material. The mass ratio of melamine, ferric nitrate, and copper sulfate was 5-10: 0.5-2.0: 0.5-2.0.

[0008] The invention discloses an application of the magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material prepared by the invention in catalyzing the degradation of pollutants in water by persulfate.

[0009] The present invention uses melamine as the carbon and nitrogen sources, and ferric nitrate and copper sulfate as the iron and copper sources, respectively, to synthesize a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material in a single step using a high-temperature pyrolysis method. Adsorption and degradation experiments show that the magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material not only exhibits excellent adsorption properties for the dye methylene blue, but also enables efficient oxidative degradation. The magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material prepared by the present invention not only exhibits excellent catalytic performance but is also easily recovered by magnetic separation, making it suitable for the efficient treatment of dye wastewater.

[0010] The present invention has the following beneficial effects:

[0011] 1. The raw materials used in the present invention are easily available and the preparation process is simple; a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material is prepared for the first time by a one-step method;

[0012] 2. The present invention mixes these three substances into a composite material, utilizing the excellent conductivity and electron-rich properties of N-doped carbon and the catalytic activity of Fe and Cu active sites on peroxymonosulfate to achieve efficient degradation and removal of methylene blue. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is the XRD pattern of magnetic Fe3O4 / Cu / nitrogen-doped carbon composite;

[0014] Figure 2 This is the degradation curve of methylene blue by peroxymonosulfate activated by magnetic Fe3O4 / Cu / nitrogen-doped carbon material. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any combination of the specific implementation methods.

[0016] Specific embodiment 1: The method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material in one step in this embodiment is carried out according to the following steps:

[0017] Melamine, ferric nitrate, and copper sulfate were placed in a mortar and ground until completely mixed to obtain a mixed sample. The mixed sample was then placed in a porcelain boat and transferred to a tube furnace for pyrolysis at 650-850°C under protective gas and then cooled to room temperature to obtain a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material. The mass ratio of melamine, ferric nitrate, and copper sulfate was 5-10: 0.5-2.0: 0.5-2.0.

[0018] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the mass ratio of melamine, ferric nitrate, and copper sulfate is 10:1.0:1.0. Other aspects are the same as specific embodiment 1.

[0019] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that the protective gas is argon. Other aspects are the same as specific embodiment 1 or 2.

[0020] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the temperature is 800° C. The rest is the same as specific embodiments 1 to 3.

[0021] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the pyrolysis time is 60 to 180 minutes. Other aspects are the same as specific embodiments 1 to 4.

[0022] Specific embodiment six: This embodiment uses the magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material in catalyzing the degradation of pollutants in water with persulfate.

[0023] Specific embodiment 7: This embodiment differs from specific embodiment 6 in that the pollutant is a dye. Other aspects are the same as specific embodiment 6.

[0024] Specific embodiment eight: This embodiment differs from specific embodiment seven in that the dye is methylene blue. Other aspects are the same as specific embodiment seven.

[0025] The following examples are used to verify the beneficial effects of the present invention:

[0026] Example 1 The one-step method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material in this example is carried out by the following steps:

[0027] 1.0 g of melamine, 0.1 g of ferric nitrate and 0.1 g of copper sulfate were placed in a mortar and ground until completely mixed to obtain a mixed sample; the mixed sample was then placed in a porcelain boat and subsequently transferred to a tube furnace and pyrolyzed at 800°C for 120 min under argon gas. The mixture was then cooled to room temperature to obtain a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material.

[0028] The XRD pattern of the magnetic Fe3O4 / Cu / nitrogen-doped carbon material obtained in this example is as follows Figure 1As shown in the figure, the mantou peak at around 26.4° is attributed to the (002) crystal plane of graphitic carbon (PDF ##89-7213), the diffraction peaks at 30.2°, 35.5°, 53.6°, 57.1°, and 62.7° are attributed to the (220), (311), (422), (511), and (440) crystal planes of magnetic Fe3O4 (PDF#88-0315), and the diffraction peaks at 43.3°, 50.4°, and 74.1° are attributed to the (111), (200), and (220) crystal planes of Cu (PDF#89-2838). Therefore, the composite material contains graphitic carbon, magnetic Fe3O4, and zero-valent copper phases.

[0029] 10 mg of magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material was added into 10 mg / L methylene blue solution, and the degradation curve was as follows: Figure 2 As shown in the figure, after 20 minutes of adsorption, the relative concentration of methylene blue in the solution dropped to 33.6%, and the relative adsorption capacity of methylene blue by the composite material reached 66.4%. Subsequently, 25 mg of peroxymonosulfate was added, and degradation began. After 15 minutes of degradation, the relative concentration of methylene blue in the solution further dropped to 2.0%. Therefore, through adsorption and degradation, the removal rate of methylene blue reached 98.0%. In summary, the magnetic Fe₃O₄ / Cu / nitrogen-doped carbon composite shows potential for the application of peroxymonosulfate activation to degrade dye wastewater.

Claims

1. A one-step method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material, characterized in that The method proceeds as follows: Melamine, ferric nitrate, and copper sulfate were placed in a mortar and ground until completely mixed to obtain a mixed sample. The mixed sample was then placed in a porcelain boat and transferred to a tube furnace for pyrolysis at 650-850°C under protective gas and then cooled to room temperature to obtain a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material. The mass ratio of melamine, ferric nitrate, and copper sulfate was 5-10: 0.5-2.0: 0.5-2.

0.

2. The one-step method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material according to claim 1, characterized in that: The mass ratio of melamine, ferric nitrate and copper sulfate is 10:1.0:1.

0.

3. The one-step method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material according to claim 1, characterized in that: The protective gas is argon.

4. The one-step method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material according to claim 1, characterized in that: The temperature is 800℃.

5. The one-step method for preparing a magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material according to claim 1, characterized in that: The pyrolysis time is 60 ~ 180 min.

6. Use of the magnetic Fe3O4 / Cu / nitrogen-doped carbon composite material prepared as claimed in claim 1 in catalyzing the degradation of pollutants in water by persulfate.

7. The use according to claim 6, characterized in that The pollutant is a dye.

8. The use according to claim 6, characterized in that The dye is methylene blue.

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