A graphene-based three-dimensional porous group modified Fe-MOFs aerogel catalyst and a preparation method and application thereof

Abstract

The present application relates to a kind of graphene-based three-dimensional porous group modified Fe-MOFs aerogel catalyst and its preparation method and application.The catalyst is three-dimensional porous composite aerogel material obtained after graphene is used as substrate, and Fe-MOFs loaded with nitrogen group modified;Preparation method includes the following steps: iron source and nitrogen-containing organic ligand are dissolved in solvent, heating reaction is carried out, reaction product is washed and dried, and group modified Fe-MOFs material is obtained;Group modified Fe-MOFs material is added to graphene oxide dispersion, then reducing agent is added, and mixed solution is obtained by stirring and ultrasonic treatment;Group modified Fe-MOFs graphene hydrogel material is obtained by water bath heating to mixed solution;After group modified Fe-MOFs graphene hydrogel material is freeze-dried, catalyst is obtained.Compared with prior art, the present application is used for photocatalytic removal of organic pollutants in water body, to achieve the purpose of environment-friendly easy catalyst recycling and utilization, and improve the removal efficiency of organic pollutants in water body.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photocatalytic materials, in particular to a graphene-based three-dimensional porous group modified Fe-MOFs aerogel catalyst and a preparation method and application thereof. BACKGROUND

[0002] Nowadays, due to the production and overuse of organic pollutants (such as pharmaceuticals and personal care products, herbicides, insecticides, etc.) mainly composed of synthetic chemicals, organic pollutants are released into the water environment through various pathways. Most of the organic pollutants are not easy to be decomposed and removed in the water body, and have biological toxicity, so the water pollution problem cannot be ignored.

[0003] Iron metal organic framework (Fe-MOFs) material is a kind of metal organic framework (MOFs) material, which is a porous material with ordered structure formed by iron ions and organic ligands. It has a certain visible light response and good water stability, so it is used for photocatalytic removal of organic pollutants in water. However, Fe-MOFs material still has defects such as insufficient high visible light response range and easy recombination of photo-generated carriers. At the same time, Fe-MOFs is a powder material, which is not easy to recycle in water, limiting its practical application in water.

[0004] Graphene aerogel is a three-dimensional space net structure porous material assembled by two-dimensional material graphene. Due to the unique advantages of aerogel in structure and performance, it is used as a high-efficiency adsorbent and catalyst material carrier in the environmental field. At the same time, it has the advantage of floating on the water surface due to its small density, increasing the contact surface of sunlight and water with the catalyst, and improving its application efficiency in actual water. However, the catalytic activity of single graphene aerogel is poor, which limits its application in the field of photocatalysis.

[0005] In recent years, in view of the advantages of Fe-MOFs and graphene aerogel, Fe-MOFs is loaded on the graphene aerogel substrate, which overcomes the defects of single material, improves the separation efficiency of photo-generated carriers, enhances the light absorption capacity of the material, and further improves the application prospect of the material in the removal of organic pollutants in water. In addition, the overflow of iron ions in Fe-MOFs will also have a certain impact on the water environment. Therefore, it is necessary to find a method to reduce the overflow of iron ions and improve the photocatalytic efficiency and recyclability of the material, which is a problem to be solved in this field. SUMMARY

[0006] The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst provided by the present application is prepared by loading group-modified Fe-MOFs on graphene as a substrate, and has a large specific surface area, reduces iron ion overflow, is environmentally friendly and easy to recycle, and improves the photocatalytic removal of organic pollutants in water.

[0007] The object of the present application can be achieved by the following technical solutions.

[0008] The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst is a three-dimensional porous composite aerogel material obtained by loading group-modified Fe-MOFs material on graphene as a substrate.

[0009] Further, the mass ratio of graphene to group-modified Fe-MOFs material is in the range of 1:(0.1-10), preferably 1:(0.5-2).

[0010] Further, the raw materials of the nitrogen group-modified Fe-MOFs include an iron source and a nitrogen-containing organic ligand.

[0011] Further, the nitrogen-containing organic ligand includes one or more of 2-amino terephthalic acid, 2-amino isophthalic acid, 2-amino-1,3,5-benzenetricarboxylic acid, aminosuccinic acid, 2-nitro terephthalic acid, 2-nitro isophthalic acid, or 2,5-pyridine dicarboxylic acid.

[0012] A preparation method of the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst as described above, the method comprising the following steps:

[0013] Dissolve the iron source and the nitrogen-containing organic ligand in a solvent, perform a heating reaction, wash and dry the reaction product to obtain the group-modified Fe-MOFs material;

[0014] Add the group-modified Fe-MOFs material to a graphene oxide dispersion solution, then add a reducing agent, and stir and ultrasonic to obtain a mixed solution;

[0015] Perform water bath heating on the mixed solution to obtain the group-modified Fe-MOFs graphene hydrogel material;

[0016] Freeze-dry the group-modified Fe-MOFs graphene hydrogel material to obtain the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst.

[0017] Further, the iron source includes one or more of ferric chloride, ferric nitrate, ferric sulfate, iron wire or iron block, and the mass ratio of the iron source to the organic ligand is 1:(0.5-3.0), preferably 1:1;

[0018] The solvent includes one or more of N,N-dimethylformamide, N,N-dimethylacetamide, methanol, ethanol, ethylene glycol or water; and the reducing agent includes one of ascorbic acid, sodium thiosulfate or ferrous ammonium sulfate.

[0019] Further, the temperature of the heating reaction is 50-240 DEG C, and the time is 8-24h, preferably 150 DEG C, 24h; the temperature of the drying is 50-200 DEG C, and the time is 5-12h; the temperature of the water bath heating is 30-90 DEG C, and the time is 5-12h, preferably 70 DEG C, 8h.

[0020] An application of the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst as described above, which is applied to photocatalytic removal of organic pollutants in water, specifically comprising the following steps:

[0021] An organic pollutant aqueous solution is prepared in a photoreactor, and the catalyst is added to the organic pollutant aqueous solution to perform dark reaction;

[0022] An oxidant is added to the photoreactor, and a light source is turned on to perform photocatalytic degradation of the organic pollutants in water.

[0023] Further, the organic pollutants are artificially synthesized organic pollutants, including ibuprofen, and the oxidant is persulfate.

[0024] Further, in the photoreactor, the mass ratio of the catalyst, the oxidant and the organic pollutant aqueous solution is 1:(1-100):(10-10000), preferably 1:(5-50):(500-5000).

[0025] Compared with the prior art, the present application has the following advantages:

[0026] (1) The raw materials of the present application are easy to obtain, the cost is low, the operation is simple, and the present application has good repeatability, which is helpful for the popularization and application of the technology;

[0027] (2) The catalyst of the present application has high photocatalytic activity. By optimizing the loading amount of the group-modified Fe-MOFs, the first-order degradation kinetic constant of photocatalytic degradation of organic pollutants in water is 30.2 and 4.6 times that of pure graphene aerogel and group-modified Fe-MOFs, respectively;

[0028] (3) The catalyst of the present application has the advantages of environmental friendliness and easy recycling and utilization; the leaching rate of iron ions is only 0.31%, which is far lower than the leaching rate of iron ions in graphene-based Fe-MOFs aerogel (3.95%). Therefore, the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst has broad application prospects in photocatalytic removal of organic pollutants in water bodies. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Transmission electron micrograph of the catalyst prepared for Example 1;

[0030] Figure 2 Raman spectrum of the catalyst prepared for Comparative Example 1 and Examples 1-5;

[0031] Figure 3 EIS Nyquist impedance diagram of the catalyst prepared for Comparative Examples 1-3 and Example 1;

[0032] Figure 4 Graph showing the photocatalytic degradation of ibuprofen of the catalyst prepared for Comparative Examples 1-3 and Examples 1-5.

[0033] Figure 5 Iron ion leaching ratio diagram of the catalyst prepared for Comparative Example 3 and Example 1 after photocatalysis. DETAILED DESCRIPTION

[0034] The present application will be described in detail below in conjunction with the accompanying drawings and specific examples. The present embodiment is implemented on the premise of the technical solution of the present application, and detailed implementation modes and specific operation processes are given, but the protection scope of the present application is not limited to the following examples.

[0035] A graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst, a preparation method and application thereof, the preparation method comprising the following steps:

[0036] S1: completely dissolving the iron source and the organic ligand in a solvent and stirring, transferring to a reaction kettle for reaction, obtaining a reaction product, washing and drying the reaction product to obtain a group-modified Fe-MOFs material; the iron source is one or more of ferric chloride, ferric nitrate, ferric sulfate, iron wire, and iron block; the organic ligand is one or more of 2-amino terephthalic acid, 2-amino isophthalic acid, 2-amino-1,3,5-benzenetricarboxylic acid, aminosuccinic acid, 2-nitro terephthalic acid, 2-nitro isophthalic acid, and 2,5-pyridine dicarboxylic acid; the mass ratio of the iron source to the organic ligand is 1:0.5-1:3.0. The solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, methanol, ethanol, ethylene glycol, and water. The reaction temperature is 50-240℃, and the reaction time is 8-24h; the drying temperature is 50-200℃, and the drying time is 5-12h.

[0037] S2: dispersing graphene oxide into deionized water to obtain a first uniform mixed solution;

[0038] S3: adding the group-modified Fe-MOFs into the first mixed solution, and then adding a reducing agent, stirring and ultrasonicating to obtain a mixed solution; the reducing agent is one of ascorbic acid, sodium thiosulfate, and ferrous ammonium sulfate.

[0039] S4: water-bath heating the mixed solution obtained in step S3 to obtain a group-modified Fe-MOFs graphene hydrogel material; the water-bath heating temperature is 30-90℃, and the water-bath heating time is 5-12h.

[0040] S5: freeze-drying the material obtained in step S4 to obtain the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst.

[0041] The catalyst uses graphene as a substrate, and loads group-modified Fe-MOFs to obtain a three-dimensional porous composite aerogel, and the group-modified Fe-MOFs is nitrogen group-modified Fe-MOFs. The mass ratio of graphene to the group-modified Fe-MOFs material is 1:(0.1-10). Preferably, 1:(0.5-2). The catalyst is applied to photocatalytic removal of organic pollutants in water. The organic pollutants are artificially synthesized organic pollutants.

[0042] The chemical reagents and instruments used in the following examples are commercially available.

[0043] Comparative Example 1

[0044] A preparation method of a graphene aerogel, the steps of which are as follows:

[0045] Step S1: dissolving graphene oxide in deionized water, ultrasonicating for 30min to obtain a uniform graphene oxide solution with a concentration of 3mg / mL.

[0046] Step S2, ascorbic acid was added into the graphene oxide solution in an amount equal to that of the graphene oxide, and stirred for 10 min to obtain a mixed solution.

[0047] Step S3, the mixed solution of S2 was transferred into a glass container for molding, and ultrasonic was applied to remove bubbles.

[0048] Step S4, the glass container of S3 was sealed with a plastic wrap, and heated in a water bath at 70°C for 8 h to obtain a graphene hydrogel.

[0049] Step S5, the graphene hydrogel obtained in S4 was dialyzed against pure water for 2-3 days, and freeze-dried to obtain a pure graphene aerogel, which was named as GA.

[0050] Comparative Example 2

[0051] A preparation method of a nitrogen group modified Fe-MOFs structure MIL-53(Fe)-NH2, the steps of which are as follows:

[0052] Step S1, ferric chloride and 2-amino terephthalic acid were completely dissolved in N,N-dimethylformamide at a ratio of 1:1, and stirred until a uniform solution was formed.

[0053] Step S2, the solution obtained in S1 was transferred into a stainless steel reaction kettle with a polytetrafluoroethylene lining, and reacted at 150°C for 24 h to obtain MIL-53(Fe)-NH2.

[0054] Comparative Example 3

[0055] A preparation method of a catalyst with a mass ratio of graphene to Fe-MOFs material MIL-53(Fe) of 1:1, the steps of which are as follows:

[0056] Step S1, ferric chloride and terephthalic acid were completely dissolved in N,N-dimethylformamide at a ratio of 1:1, and stirred until a uniform solution was formed.

[0057] Step S2, the solution obtained in S1 was transferred into a stainless steel reaction kettle with a polytetrafluoroethylene lining, and reacted at 150°C for 24 h to obtain MIL-53(Fe).

[0058] Step S3, graphene oxide was dissolved in deionized water, and an equal amount of MIL-53(Fe) was added, and ultrasonic was applied for 30 min to obtain a uniform mixed solution.

[0059] Step S4, ascorbic acid was added into the graphene oxide solution in an amount equal to that of the graphene oxide, and stirred for 10 min to obtain a mixed solution.

[0060] Step S5, the mixed solution of S4 is transferred to a glass container for molding, and bubbles are removed by ultrasonic.

[0061] Step S6, the glass container of S5 is sealed with plastic wrap, and heated in a water bath at 70°C for 8h to obtain a hydrogel.

[0062] Step S7, the hydrogel obtained in S6 is dialyzed with pure water for 2-3 days, and freeze-dried to obtain a graphene-based MIL-53(Fe) composite aerogel, named GMA-1.

[0063] Example 1

[0064] A preferred preparation method of a graphene and group-modified Fe-MOFs material MIL-53(Fe)-NH2 with a mass ratio of 1:1, comprising the following steps:

[0065] Step S1, iron chloride and 2-amino terephthalic acid are completely dissolved in N,N-dimethylformamide at a ratio of 1:1, and stirred until a uniform solution is formed.

[0066] Step S2, the solution obtained in S1 is transferred to a stainless steel reaction kettle with a polytetrafluoroethylene lining and reacted at 150°C for 24h to obtain MIL-53(Fe)-NH2.

[0067] Step S3, graphene oxide is dissolved in deionized water, and an equal amount of MIL-53(Fe)-NH2 is added, and ultrasonic treatment is performed for 30min to obtain a uniform mixed solution.

[0068] Step S4, an equal amount of ascorbic acid is added to the solution obtained in S3, and stirred for 10min to obtain a mixed solution.

[0069] Step S5, the mixed solution of S4 is transferred to a glass container for molding, and bubbles are removed by ultrasonic.

[0070] Step S6, the glass container of S5 is sealed with plastic wrap, and heated in a water bath at 70°C for 8h to obtain a hydrogel.

[0071] Step S7, the hydrogel obtained in S6 is dialyzed with pure water for 2-3 days, and freeze-dried to obtain a graphene and MIL-53(Fe)-NH2 composite aerogel with a mass ratio of 1:1, named GMAN-1.

[0072] Example 2

[0073] A preparation method of graphene and group-modified Fe-MOFs material MIL-53(Fe)-NH2 with a mass ratio of 1:0.5, comprising the following steps:

[0074] Steps S1, S2, S4, S5 and S6 are the same as those in Example 1.

[0075] Step S3, the graphene oxide is dissolved in deionized water, 0.5 times the mass of graphene oxide of MIL-53(Fe)-NH2 is added, and ultrasonic is performed for 30 min to obtain a uniform mixed solution.

[0076] Step S7, the hydrogel obtained in S6 is dialyzed with pure water for 2-3 days, and freeze-dried to obtain a composite aerogel with a mass ratio of graphene to MIL-53(Fe)-NH2 of 1:0.5, which is named as GMAN-0.5.

[0077] Example 3

[0078] A preparation method of a graphene and a group-modified Fe-MOFs material MIL-53(Fe)-NH2 with a mass ratio of 1:0.75, comprising the following steps:

[0079] Steps S1, S2, S4, S5 and S6 are the same as those in Example 1.

[0080] Step S3, the graphene oxide is dissolved in deionized water, 0.75 times the mass of graphene oxide of MIL-53(Fe)-NH2 is added, and ultrasonic is performed for 30 min to obtain a uniform mixed solution.

[0081] Step S7, the hydrogel obtained in S6 is dialyzed with pure water for 2-3 days, and freeze-dried to obtain a composite aerogel with a mass ratio of graphene to MIL-53(Fe)-NH2 of 1:0.75, which is named as GMAN-0.75.

[0082] Example 4

[0083] A preparation method of a graphene and a group-modified Fe-MOFs material MIL-53(Fe)-NH2 with a mass ratio of 1:1.5, comprising the following steps:

[0084] Steps S1, S2, S4, S5 and S6 are the same as those in Example 1.

[0085] Step S3, the graphene oxide is dissolved in deionized water, 1.5 times the mass of graphene oxide of MIL-53(Fe)-NH2 is added, and ultrasonic is performed for 30 min to obtain a uniform mixed solution.

[0086] Step S7, the hydrogel obtained in S6 is dialyzed with pure water for 2-3 days, and freeze-dried to obtain a composite aerogel with a mass ratio of graphene to MIL-53(Fe)-NH2 of 1:1.5, which is named as GMAN-1.5.

[0087] Example 5

[0088] A preparation method of a graphene and group modified Fe-MOFs material MIL-53(Fe)-NH2 with a mass ratio of 1:2, comprising the following steps:

[0089] Steps S1, S2, S4, S5 and S6 are the same as those in Example 1.

[0090] Step S3, the graphene oxide is dissolved in deionized water, 2 times the mass of the graphene oxide of MIL-53(Fe)-NH2 is added, and ultrasonic treatment is performed for 30 min to obtain a uniform mixed solution.

[0091] Step S7, the hydrogel obtained in S6 is dialyzed with pure water for 2-3 days, and freeze-dried to obtain a graphene and MIL-53(Fe)-NH2 composite aerogel with a mass ratio of 1:2, which is named as GMAN-2.

[0092]

Performance characterization

[0093] The catalysts prepared in Comparative Examples 1-3 and Examples 1-5 of the application are characterized, specifically including:

[0094] I. Transmission electron microscopy characterization of GMAN-1

[0095] Specifically, Figure 1 The transmission electron microscopy image of the GMAN-1 composite photocatalyst prepared according to Example 1 is shown. Figure 1 a The transmission electron microscopy image shows that the wrinkled two-dimensional graphene oxide nanosheet is observed, and the number of wrinkles of GMAN-1 is obviously increased. Figure 1 b The transmission electron microscopy image shows that the number of strip-like loadings with lines is obviously increased. Figure 1 c and d The high-magnification transmission electron microscopy images show that there is a clear boundary line between graphene oxide and MOFs derivatives.

[0096] II. Raman spectroscopy characterization of GA and graphene-based aerogel catalysts loaded with different MIL-53(Fe)-NH2

[0097] Specifically, Figure 2 GA and graphene-based aerogel catalysts loaded with different MIL-53(Fe)-NH2 prepared in Comparative Example 1 and Examples 1-5 are clearly shown. It can be seen that all the Raman results show similar spectra, and the prepared catalysts have two scattering peaks at 1349.6 and 1590.3 cm -1 The D peak and the G peak, respectively representing the degree of structural defects and the degree of graphitization of the material. After loading MIL-53(Fe)-NH2, the intensity of the D peak is significantly higher than that of GA, indicating that the defects in the GMAN composite aerogel are increased, and these defects can inhibit the recombination of electron-hole pairs, thereby improving the photocatalytic activity of the aerogel.

[0098] III. EIS Nyquist Impedance Characterization of GA, MIL-53(Fe)-NH2, GMA-1 and GMAN-1

[0099] In particular, Figure 3 EIS Nyquist impedance plots of GA, MIL-53(Fe)-NH2, GMA-1 and GMAN-1 according to Comparative Examples 1-3 and Example 1 are shown. It can be seen that GMAN-1 has the smallest Nyquist arc radius, so its current impedance is smaller than other catalysts. It indicates that the separation efficiency of photo-generated carriers of GMAN-1 catalyst is the highest.

[0100] IV. Specific Surface Area of MIL-53(Fe)-NH2 and Different MIL-53(Fe)-NH2 Loaded Graphene Aerogel Catalysts

[0101] In particular, Table 1 shows the specific surface area and pore size results of the prepared MIL-53(Fe)-NH2 and different MIL-53(Fe)-NH2 loaded graphene-based aerogel catalysts according to Comparative Example 2 and Examples 1-5. It can be seen that the surface area of the graphene-based catalysts loaded with MIL-53(Fe)-NH2 is greatly improved compared to pure MIL-53(Fe)-NH2 (41 m 2 ·g -1 ), especially the specific surface area of GMAN-1 reaches 975 m 2 ·g -1 . The increase of the specific surface area of the catalyst improves the photocatalytic degradation performance of the material.

[0102] Table 1 Specific surface area and pore size results of the catalysts prepared in Examples 1-5 and Comparative Example 1

[0103] Sample Specific surface area (m 2 ·g -1 )]]> Total pore volume (cm 3 ·g -1 )]]> Pore size (nm) MIL-53(Fe)-NH2 41 0.02 1.7 GMAN-0.5 78 0.03 1.7 GMAN-0.75 249 0.06 1.9 GMAN-1 975 0.34 3.8 GMAN-1.5 184 0.06 3.8 GMAN-2 176 0.05 2.5

[0104] Application Example

[0105] The specific method of application is: a certain amount of graphene-based three-dimensional porous group modified Fe-MOFs aerogel is added to the quartz tube of the photocatalytic reaction device. The catalyst is carried out in the reaction device composed of quartz tube, control system, stirring system, cooling system, light source and box body to photocatalytically reduce ibuprofen in water body. In the initial stage, dark reaction is carried out for 0.5-2h to make the reaction system reach adsorption and desorption balance, and the light source is turned on at the same time with the addition of persulfate to carry out the light reaction stage. The concentration of ibuprofen is detected by high performance liquid chromatograph.

[0106] According to Comparative Examples 1-3 and Examples 1-5, the prepared catalysts are used as photocatalysts to photocatalytically degrade ibuprofen in water body, which specifically includes the following steps:

[0107] Step S1, the concentration of the ibuprofen aqueous solution is accurately configured as 10 mg / L, 50 mL of the ibuprofen solution is added into the quartz tube;

[0108] Step S2, 20 mg of the catalyst is added into the quartz tube, and dark reaction is carried out for 2 h;

[0109] Step S3, 0.5 mL of the persulfate solution with a concentration of 20 g / L is added into the quartz tube of the photo-reactor, and a light source is turned on for light irradiation, the light source is a 300 W xenon lamp, so as to perform photocatalytic degradation of ibuprofen in water.

[0110] Step S4, samples are taken every certain period of time, filtered into sample bottles, and subjected to high performance liquid chromatography analysis, so as to obtain the concentration of ibuprofen.

[0111] Referring to Figure 4 It can be seen that the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel as a photocatalyst and under the condition of adding persulfate, the photocatalytic activity is improved. By optimizing the loading amount of the nitrogen group-modified Fe-MOFs, GMAN-1 has the best photocatalytic activity, and the degradation rate of ibuprofen in the photocatalytic reaction reaches 100% in 20 min, and the degradation kinetic constant of ibuprofen in the photocatalytic degradation of water is 30.2 and 4.6 times that of pure GA and MIL-53(Fe)-NH2, respectively.

[0112] Referring to Figure 5 It can be seen that the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel as a photocatalyst, the leaching rate of iron ions in the aqueous solution (leaching rate = iron ion content in the aqueous solution / iron ion content in the catalyst before use) is significantly reduced, and has environmental friendliness. The leaching concentration of iron ions of GMA-1 and GMAN-1 accounts for 3.95% and 0.31%, respectively. The leaching rate of iron ions of GMAN-1 is more than 10 times less than that of GMA-1.

[0113] The above is only a preferred embodiment of the present application, and is not intended to limit the other forms of the present application. Any skilled person in the art can use the disclosed technical content to make changes or modifications into equivalent embodiments. However, any simple modification, equivalent change and modification made on the above embodiments according to the technical essence of the present application, without departing from the technical solution content of the present application, still belongs to the protection scope of the present application.

Claims

1. A graphene-based three-dimensional porous group modified Fe-MOFs aerogel catalyst, characterized in that: The catalyst is a three-dimensional porous composite aerogel material obtained by using graphene as a substrate and loading a group-modified Fe-MOFs material; the group-modified Fe-MOFs material is a nitrogen group-modified Fe-MOFs; The preparation method of the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst comprises the following steps: The iron source and the nitrogen-containing organic ligand are dissolved in a solvent, heated to react, and the reaction product is washed and dried to obtain a group-modified Fe-MOFs material; The group-modified Fe-MOFs material is added to the graphene oxide dispersion, and then a reducing agent is added, and the mixture is stirred and ultrasonicated to obtain a mixed solution; The mixed solution is heated in a water bath to obtain a group-modified Fe-MOFs graphene hydrogel material; The group-modified Fe-MOFs graphene hydrogel material is freeze-dried to obtain a graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst; Wherein, the reducing agent includes one of ascorbic acid, sodium thiosulfate or ferrous ammonium sulfate.

2. The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 1, characterized in that: The mass ratio of graphene to group-modified Fe-MOFs material ranges from 1: (0.1-10).

3. The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 2, characterized in that: The mass ratio of graphene to group-modified Fe-MOFs material ranges from 1: (0.5-2).

4. The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 1, characterized in that: The nitrogen-containing organic ligand includes one or more of 2-aminoterephthalic acid, 2-aminoisophthalic acid, 2-amino-1,3,5-pyromellitic acid, aminosuccinic acid, 2-nitroterephthalic acid, 2-nitroisophthalic acid or 2,5-pyridinedicarboxylic acid.

5. The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 1, characterized in that: The iron source includes one or more of ferric chloride, ferric nitrate, ferric sulfate, iron wire or iron block, and the mass ratio of the iron source to the organic ligand is 1: (0.5-3.0); The solvent includes one or more of N,N-dimethylformamide, N,N-dimethylacetamide, methanol, ethanol, ethylene glycol or water.

6. The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 5, characterized in that: The mass ratio of iron source to organic ligand is 1:

1.

7. The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 1, characterized in that: The temperature of the heating reaction is 50-240°C and the time is 8-24 h; the temperature of the drying is 50-200°C and the time is 5-12 h; the temperature of the water bath heating is 30-90°C and the time is 5-12 h.

8. The graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 7, characterized in that: The heating reaction temperature was 150 °C and the time was 24 h; The water bath was heated at 70°C for 8 h.

9. An application of the graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to any one of claims 1 to 8, characterized in that: The catalyst is used for photocatalytic removal of organic pollutants in water, specifically comprising the following steps: An organic pollutant aqueous solution is prepared in a photoreactor, and a catalyst is added to the organic pollutant aqueous solution to perform a dark reaction; An oxidant is added to the photoreactor, and a light source is turned on for illumination to photocatalytically degrade organic pollutants in the water.

10. The use of a graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 9, characterized in that: The organic pollutants are artificially synthesized organic pollutants, including ibuprofen, and the oxidant is persulfate.

11. The use of a graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 9, characterized in that: In the photoreactor, the mass ratio of the catalyst, the oxidant and the organic pollutant aqueous solution is 1: (1-100): (10-10000).

12. The use of a graphene-based three-dimensional porous group-modified Fe-MOFs aerogel catalyst according to claim 11, characterized in that: In the photoreactor, the mass ratio of catalyst, oxidant and organic pollutant aqueous solution is 1: (5-50): (500-5000).

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