A preparation method of metal organic framework nanorod cluster / rGO composite material

Abstract

This invention relates to a method for preparing a metal-organic framework nanorod cluster / rGO composite. The method involves placing a one-dimensional MOF / rGO composite in a sealed reactor and irradiating it with microwaves in a controlled atmosphere to produce a composite material composed of MOF nanorod clusters and rGO. Compared to existing technologies, this method utilizes the microwave popcorn effect to alter the composite's structure, significantly increasing the material's specific surface area and active sites, offering significant potential for application.

Description

Technical Field

[0001] The present invention relates to the technical field of nanomaterials, and in particular to a method for preparing a metal organic framework nanorod cluster / rGO composite material based on microwave popcorn effect. Background Art

[0002] Metal organic frameworks (MOFs) are organic-inorganic hybrid materials with intramolecular pores formed by self-assembly of organic ligands and metal ions or clusters through coordination bonds. MOF materials have an ordered porous structure, a large specific surface area, and adjustable organic ligands or metal ions, and have broad application prospects. However, due to the poor conductivity of MOFs, their practical application is limited. Graphene is a sp 2 Two-dimensional materials composed of hybrid carbon atoms have extremely high electron mobility (250,000 cm 2 ·V -1 ·s -1 ) and large specific surface area (2630m 2 ·g -1 If MOF materials can be effectively combined with graphene-based materials (such as GO / rGO), the conductivity of MOF materials can be effectively improved, and more adsorption and catalytic sites can be provided, expanding their applications in various fields. However, most MOFs have large crystal structures, which cannot effectively expose active sites and cannot form maximum interfacial contact with rGO. Therefore, it is necessary to develop a method to achieve a composite interface with good compatibility, electron transport, and stability between MOFs of specific morphology and rGO.

[0003] Patent application 202310704536.0 discloses a metal-organic framework-graphene composite material, which is composed of a metal-organic framework and functionalized graphene composited together through supramolecular interactions; the organic ligand molecule of the metal-organic framework is tetracarboxyphenylporphyrin iron, and the coordinated metal ion is at least one of cobalt, nickel, copper, and zinc; the functionalized graphene is graphene modified with organic small molecules, and the organic small molecules include at least one of 5-amino-1-naphthalenesulfonic acid, sodium anthraquinone-2-sulfonate, and naphthalene-1-sulfonic acid. The metal organic framework host of this invention and the functionalized graphene guest form a heterogeneous structure through supramolecular interaction, which is conducive to the electronic conduction of the composite material and greatly improves the gas sensing performance. It has the characteristics of strong selectivity, high sensitivity, low power consumption, and high stability. However, it is difficult for MOF to be precisely positioned on the graphene sheet. MOF is prone to self-assembly and crystallization, and is prone to agglomeration, resulting in a reduction in catalytic active sites, which hinders the formation of an effective interface between MOF and graphene. In addition, MOF materials have poor thermal stability. Traditional calcination methods for enhancing the interface can easily lead to the collapse of the pore structure and the conversion of MOF materials into metal elements or metal carbides, which lose their semiconductor properties and become completely inactivated. Therefore, how to develop a new catalyst synthesis method to achieve the precise placement of MOF materials on the graphene surface and interface enhancement is particularly important for improving the photocatalytic performance of MOF-rGO composite materials. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method for preparing metal organic framework nanorod clusters / rGO composite materials which can greatly improve the specific surface area and active sites of the material and significantly strengthen the composite interface between MOF and rGO.

[0005] The objectives of the present invention can be achieved through the following technical solutions: a method for preparing a metal organic framework nanorod cluster / rGO composite material, wherein a MOF / rGO composite material with a one-dimensional structure is placed in a closed reactor and subjected to microwave irradiation in a certain atmosphere to obtain a composite material formed by nanorod cluster MOF and rGO.

[0006] Furthermore, the MOF material uses metal ions as the metal center and tetrakis(4-carboxyphenyl)porphine (TCPP), terephthalic acid (PTA), 2-aminoterephthalic acid (H2ATA) or trimesic acid (H3BTC) as the ligand.

[0007] Furthermore, the metal ions include Zr 4+ 、Fe 3+ 、V 4+ 、Bi 3+ 、Ti 4+ 、Zn 2+ 、Co 3+ 、Cu2+ .

[0008] Furthermore, the MOF and rGO composite material is prepared by the following method:

[0009] The ligand is dissolved in a solvent, and metal salt and graphene powder are added. The mixture is stirred and ultrasonicated for 0.5 to 1 hour to form a suspension. The suspension is transferred to a microwave reactor, heated to 90-180°C, reacted for 0.5-2 hours, cooled to room temperature, centrifuged, washed to obtain a solid product, and dried at 70 to 90°C to obtain a MOF / rGO composite material with a one-dimensional structure.

[0010] Furthermore, the mass ratio of the ligand to the graphene powder is 100:5-40.

[0011] Furthermore, the solvent is N,N-dimethylformamide.

[0012] Furthermore, during the microwave irradiation process, the microwave power is 50 to 1200 W and the microwave frequency is 1 to 15 GHz.

[0013] Furthermore, the certain atmosphere is air, argon, nitrogen, carbon dioxide or vacuum. Preferably, vacuum or nitrogen,

[0014] Furthermore, the microwave irradiation time is 2-600s, and the number of irradiation cycles is 1-10 times.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The principle of microwave popcorn is to use microwave radiation energy to trigger the thermal expansion and contraction of the water vapor inside the popcorn, causing the popcorn to expand rapidly and form a fluffy structure. This method uses the microwave absorption and heat release properties of reduced graphene oxide to create in-situ hotspots, allowing the nano-bundled MOF material placed on reduced graphene oxide (rGO) to "pop" like popcorn under the action of solid-phase microwaves. The original one-dimensional MOF structure expands into a nanorod cluster structure, which comes into close contact with the rGO. This structural change significantly increases the material's specific surface area and active sites, significantly strengthening the composite interface between the MOF and rGO.

[0017] This invention utilizes a microwave modification method, which is simple, environmentally friendly, and highly efficient. Furthermore, a solid-phase microwave method is used to create in-situ hotspots, generating a microwave popcorn effect. This allows for controlled adjustment of the selected MOF morphology, significantly strengthening the composite interface between the MOF material and rGO, and further enhancing material performance. For example, the metal-organic framework nanorod cluster / rGO composite material obtained after solid-phase microwave treatment exhibits high conversion and selectivity for NO oxidation, and also improves the material's photocatalytic properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 These are the SEM images of the stone metal organic framework nanorod clusters / rGO composite material prepared in Example 1 and the sample before microwave.

[0019] Figure 2 XRD patterns of the metal organic framework nanorod cluster / rGO composite material and the sample before microwave preparation obtained in Example 2;

[0020] Figure 3 N2 adsorption-desorption isotherms of the metal organic framework nanorod cluster / rGO composite material and the sample before microwave preparation obtained in Example 3;

[0021] Figure 4 Comparison of NO oxidation performance of the metal organic framework nanorod cluster / rGO composite materials prepared in Examples 1 to 5 and the pre-microwave sample of Example 3 under LED simulated sunlight;

[0022] Figure 5 Comparison of the NO oxidation performance of the metal organic framework nanorod cluster / rGO composite material prepared in Example 6 with that of Comparative Examples 1 and 2 under LED simulated sunlight;

[0023] Figure 6 This is a comparison of the photocatalytic CO2 reduction performance of the metal organic framework nanorod cluster / rGO composite material prepared in Example 8 and Example 9 and the sample before microwave under the same conditions;

[0024] Figure 7 This is a comparison of the photocatalytic CO2 reduction performance of the metal organic framework nanorod cluster / rGO composite material prepared in Example 10 and Example 11 and the sample before microwave under the same conditions;

[0025] Figure 8 This is a comparison chart of the photocatalytic CO2 reduction performance of the metal organic framework nanorod cluster / rGO composite material prepared in Example 12 and Example 13 and the pre-microwave sample under the same conditions. DETAILED DESCRIPTION

[0026] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] The composite catalytic material of the present invention mainly uses the microwave method to compound MOF and rGO. Microwave is an electromagnetic wave with a wavelength between infrared and radio waves, usually defined as a wavelength range between 1 mm and 1 m. Microwave is a low-energy electromagnetic radiation that can propagate in transparent media such as air, glass, and plastic, and has some special physical and chemical properties. Microwave technology is widely used in the fields of communication and wireless technology, medical diagnosis and treatment, astronomical observation, and material synthesis and processing. Especially in the field of material synthesis and processing, the microwave method is a synthesis method that acts on the inside of the material and achieves an efficient and uniform thermal effect from the inside out by affecting the dipole vibration of the molecules. In solid-phase heating, based on the ultra-high wave absorption and heat release properties of carbon-based materials, rapid chemical reactions can be achieved within seconds.

[0028] The metal organic framework nanorod cluster / rGO composite material of the present invention is prepared by the following method:

[0029] S1: Preparation of MOF material: dissolve the ligand in a solvent, add metal salt and graphene powder (GO), stir and ultrasonicate for 0.5-1h to form a suspension, and transfer the suspension to a polytetrafluoroethylene microwave reactor, heat to 90-180℃, react for 0.5-2h, cool to room temperature, centrifuge and wash the solid product with DMF and methanol, and dry at 70-90℃ to obtain a MOF / rGO composite material;

[0030] The MOF material uses metal ions such as Zr, Fe, V, Bi, Ti, Zn, Co, and Cu as the metal center, and four organic molecules: tetrakis(4-carboxyphenyl)porphine (TCPP), terephthalic acid (PTA), 2-aminoterephthalic acid (H2ATA), and trimesic acid (H3BTC) as ligands. The solvent is N,N-dimethylformamide (DMF). GO is commercially available from Shenzhen Suiheng, model SH-GO-1208.

[0031] S2: irradiation using solid-phase microwaves;

[0032] The MOF / rGO composite material obtained in step S1 is placed in a quartz sealed container and irradiated with solid-phase microwave to obtain a product; the reaction conditions during the microwave irradiation process are set to a microwave power of 50 to 1200 W, a microwave frequency of 1 to 15 GHz, and a reaction atmosphere of air, argon, nitrogen, carbon dioxide or vacuum.

[0033] The following examples are implemented based on the above technical solutions of the present invention, and provide detailed implementation methods and specific operating processes, but the protection scope of the present invention is not limited to the following examples.

[0034] Example 1:

[0035] Metal-organic framework nanorod clusters / rGO composite materials were prepared by the following method:

[0036] S1: Add 100 mg of TCPP to 50 mL of DMF solution and stir to form a transparent purple solution. Add 150 mg of zirconium tetrachloride (ZrCl4) and 48 mg of GO powder to the brown solution. After that, stir and ultrasonicate the mixture for 30 minutes to form a suspension. The suspension was transferred to a polytetrafluoroethylene microwave reactor and heated to 100°C within 15 minutes using a programmed microwave digestion system. After the microwave reactor was kept warm at 90°C for 30 minutes, it was cooled to room temperature. The solid product was centrifuged and washed with DMF and methanol to obtain the solid product. It was dried at 80°C to form a dark red powder, and a Zr-TCPP / rGO composite material sample (morphology as shown) was obtained. Figure 1 (as shown in a).

[0037] S2: The sample was evenly placed at the bottom of a quartz sealed container, the reaction atmosphere was air, and then the microwave frequency was 2.45 GHz, the microwave power was 300 W, and the reaction was carried out for 5 seconds to obtain a deep red powder (morphology as shown in FIG. Figure 1 (as shown in b).

[0038] The microstructure and structure of the composite material sample prepared in Example 1 were characterized by transmission electron microscopy (SEM, FEIQuanta FEG). Figure 1 As shown in (ab), a is the morphology of the MOF nanorod cluster / rGO composite material prepared in Example 1 before microwave reaction, and b is the morphology after microwave reaction. It can be found that after solid-phase microwave thermal shock, the MOF nanorods combined with rGO exploded from the center to form a nanorod cluster assembled flower ball structure, which greatly improved the specific surface area and the interface coupling with rGO.

[0039] Example 2:

[0040] The preparation method differed from that in Example 1 in that 12 mg of GO was added and the reaction temperature was 120°C. The sample was evenly placed at the bottom of a sealed quartz container in an Ar atmosphere. The reaction was then conducted at a microwave frequency of 2.45 GHz and a microwave power of 500 W for 15 seconds to obtain a deep red powder.

[0041] The crystal structure of the samples was characterized by X-ray diffraction (XRD, Bruker D8 ADVANCE). The XRD patterns of the metal organic framework nanorod cluster / rGO composite material prepared in Example 2 and the sample before microwave heating are shown in FIG. Figure 2 As shown in Figure 3, XRD confirmed that the crystallinity was significantly improved after microwave irradiation.

[0042] Example 3:

[0043] The preparation method differed from that in Example 1 in that 24 mg of GO was added and the reaction temperature was 150°C. The sample was evenly placed at the bottom of a sealed quartz container in a vacuum atmosphere. The reaction was then carried out at a microwave frequency of 2.45 GHz and a microwave power of 700 W for 5 seconds to obtain a deep red powder.

[0044] Figure 3 The N2 adsorption-desorption isotherms of the metal organic framework nanorod cluster / rGO composite material and the sample before microwave preparation in Example 3; Figure 3 It can be seen that the adsorption capacity of the sample before microwave is 239.4m 2 / g, and the adsorption capacity of the sample obtained after microwave was 586.1m 2 / g, it can be seen that the specific surface area is increased due to the change in the solid-phase morphology after microwave treatment of the present invention, thereby greatly improving the adsorption capacity of the material.

[0045] Example 4:

[0046] The preparation method of Zr-TCPP / rGO composite material samples was the same as that in Example 1. The samples were evenly placed at the bottom of a quartz sealed container in a reaction atmosphere of CO2. The mixture was then subjected to a microwave frequency of 5.45 GHz and a microwave power of 900 W for 30 seconds to obtain a deep red powder.

[0047] Example 5:

[0048] The Zr-TCPP / rGO composite material sample preparation method is the same as that in Example 2. The sample is evenly placed at the bottom of a quartz sealed container in a reaction atmosphere of N2. Then, the sample is irradiated at a microwave frequency of 7.45 GHz and a microwave power of 1200 W for 120 s. The number of irradiation cycles is 2, and a black-red powder is obtained.

[0049] Figure 4 The NO oxidation performance of the metal organic framework nanorod cluster / rGO composite materials prepared in Examples 1 to 5 and the pre-microwave sample of Example 3 under LED simulated sunlight is compared; it can be seen from the figure that the NO removal rate of MOF / rGO after microwave irradiation is significantly improved compared with that before microwave irradiation, among which Example 3 has the highest NO removal rate, reaching 68.5%.

[0050] Example 6:

[0051] The Zr-TCPP / rGO composite material sample preparation method was the same as in Example 3. The sample was evenly placed at the bottom of a quartz sealed container in a reaction atmosphere of N2. The sample was then irradiated at a microwave frequency of 10.45 GHz and a microwave power of 1200 W for 240 s. The number of irradiation cycles was 4, yielding a black-red powder.

[0052] Example 7:

[0053] The preparation method differed from that in Example 1, except that 6 mg of GO was added and the reaction temperature was 150°C. The sample was evenly placed at the bottom of a sealed quartz container in a vacuum atmosphere. The sample was then irradiated at a microwave frequency of 2.45 GHz, a microwave power of 700 W, a reaction time of 600 s, and 10 irradiation cycles to obtain a black-red powder.

[0054] Example 8:

[0055] The preparation method differs from that of Example 1 in that the ligand is PTA and the metal source is vanadyl sulfate (VOSO4). The sample is evenly placed at the bottom of a sealed quartz container in an air-filled reaction atmosphere. The reaction is then conducted at a microwave frequency of 2.45 GHz and a microwave power of 300 W for 30 seconds to obtain a gray-green powder.

[0056] Example 9:

[0057] The preparation method differed from that of Example 8, except that 30 mg of GO was added. The sample was evenly placed at the bottom of a sealed quartz container in a vacuum atmosphere. The reaction was then carried out at a microwave frequency of 2.45 GHz and a microwave power of 700 W for 30 seconds to obtain a gray-green powder.

[0058] Example 10:

[0059] The preparation method differed from that in Example 1, except that the ligand was H3BTC, the metal source was bismuth oxynitrate pentahydrate (Bi(NO3)3·5H2O), 24 mg of GO was added, and the reaction temperature was 150°C for 1 hour. The sample was evenly placed at the bottom of a sealed quartz container in a CO2 atmosphere. The reaction was then irradiated at a microwave frequency of 5.45 GHz and a power of 1200 W for 120 seconds. Two irradiation cycles were performed to obtain a light gray powder.

[0060] Example 11:

[0061] The preparation method differed from that in Example 10, except that 48 mg of GO was added. The sample was evenly placed at the bottom of a sealed quartz container in a nitrogen atmosphere. The sample was then irradiated at a microwave frequency of 5.45 GHz and a microwave power of 1200 W for 60 s, with one irradiation cycle, to obtain a light gray powder.

[0062] Example 12:

[0063] The preparation method differed from that in Example 1, except that the ligand was H2ATA, the metal source was ferric chloride hexahydrate (FeCl3·6H2O), the solvent was ultrapure water, and the reaction temperature was 120°C for 1 hour. The sample was evenly placed at the bottom of a sealed quartz container in an Ar atmosphere. The reaction was then conducted at a microwave frequency of 2.45 GHz and a microwave power of 300 W for 30 seconds to yield a brown powder.

[0064] Example 13:

[0065] The preparation method differs from that of Example 1 in that 24 mg of GO is added. The sample is evenly placed at the bottom of a sealed quartz container in an Ar atmosphere and then subjected to a microwave frequency of 7.45 GHz and a microwave power of 500 W for 45 seconds to obtain a brown powder.

[0066] Comparative Example 1

[0067] The MOF of Example 1 without rGO was directly placed at the bottom of a quartz sealed container in an air atmosphere, and then subjected to a microwave frequency of 2.45 GHz and a microwave power of 300 W for 5 seconds to obtain a powder.

[0068] Comparative Example 2

[0069] The MOF and rGO of Example 1 were used, mixed and then ultrasonically dispersed.

[0070] The performance tests of the materials obtained in the above examples and comparative examples are as follows:

[0071] 1. The method for testing the NO oxidation performance of the samples prepared in the above examples and comparative examples during the photocatalytic process includes the following steps:

[0072] (1) In a continuous flow reactor, the reactor surface is sealed with quartz glass;

[0073] (2) In each experiment, simulated exhaust gas containing 500 ppb NO was passed through a reactor containing 0.10 g of the composite material sample prepared in step S1 of each embodiment and comparative example (i.e., before microwave heating) and the composite material sample prepared in step S2 (i.e., after microwave heating) at a rate of 2.0 L / min.

[0074] (3) After 30 min of dark adsorption, when the photocatalyst showed an adsorption-desorption equilibrium state, the LED light (JS-LT225-32W, 420 nm to 750 nm) was turned on to simulate sunlight for photocatalytic reaction.

[0075] (4) Using NO-NO2-NO X A dynamic analyzer (Thermo Scientific 42i-TL) was used to monitor the concentration changes of NO and NO2 online.

[0076] Here are the results:

[0077] NO removal rate before microwave (%) NO removal rate after microwave treatment (%) Example 1 17.6 32.5 Example 2 19.5 36.1 Example 3 20.4 68.5 Example 4 17.6 54.7 Example 5 19.5 45.1 Example 6 20.4 49.5 Example 7 15.7 53.9 Example 8 23.4 59.5 Example 9 21.5 57.1 Example 10 15.3 47.5 Example 11 15.7 36.1 Example 12 27.5 74.3 Example 13 25.4 66.9 Comparative Example 1 13.7 13.7 Comparative Example 2 13.5 13.5

[0078] As shown in the table above, the NO oxidation performance of the metal organic framework nanorod C cluster / rGO composite materials prepared in Examples 1-13 and Comparative Examples 1-2 before and after microwave treatment under LED simulated sunlight; Figure 5 The NO oxidation performance of the metal organic framework nanorod cluster / rGO composite material prepared in Example 6 before and after microwave treatment is compared with that of Comparative Examples 1 and 2 under LED simulated sunlight;

[0079] From the above table and Figure 5 It was further confirmed that the metal organic framework nanorod clusters / rGO composite material obtained after solid phase microwave treatment had high conversion rate and high selectivity for NO oxidation, among which Example 3 had the highest NO removal rate, reaching 68.5%, and NO 3 -The selectivity reached 98.7%.

[0080] 2. The performance test method of using the samples prepared in each embodiment and comparative example as catalytic materials in the photocatalytic CO2 reduction reaction includes the following steps:

[0081] Gas-solid phase photocatalytic CO2 reduction occurs in a closed quartz glass reactor at room temperature without the addition of any sacrificial agents or co-catalysts.

[0082] (1) Add 20 mg of photocatalyst (i.e., the sample prepared in each embodiment and comparative example) and 20 mL of deionized water to the bottom of a quartz reactor for ultrasonic dispersion.

[0083] (2) The reactor was transferred to a vacuum oven and dried at 60°C. After the water was completely evaporated, the catalyst powder remained at the bottom of the reactor, forming a uniform photocatalytic layer.

[0084] (3) Take 0.084g of sodium bicarbonate (NaHCO3) powder and add it into the reactor tank. The reactor is purged with N2 for 30 minutes.

[0085] (4) 30 μL of sulfuric acid (H2SO4) (2 M) was injected into the reaction tank, and the CO2 and H2O vapor required for the photocatalytic reduction of CO2 were obtained through the reaction of H2SO4 and NaHCO3.

[0086] (5) The quartz reactor was placed under a 300 W Xe lamp light source (MC-X301, Beijing Magnesium Technology Co., Ltd.). A filter (AM1.5 G) was used, and the photocatalytic layer obtained in step (2) was 10 cm away from the light source. After 4 hours of illumination, the reactor was assembled on a gas chromatograph to analyze its composition and content.

[0087] Here are the results:

[0088]

[0089] Figure 6 This is a comparison of the photocatalytic CO2 reduction performance of the metal organic framework nanorod cluster / rGO composite material prepared in Example 8 and Example 9 and the sample before microwave under the same conditions; Figure 7 This is a comparison of the photocatalytic CO2 reduction performance of the metal organic framework nanorod cluster / rGO composite material prepared in Example 10 and Example 11 and the sample before microwave under the same conditions; Figure 8 This is a comparison chart of the photocatalytic CO2 reduction performance of the metal organic framework nanorod cluster / rGO composite material prepared in Example 12 and Example 13 and the pre-microwave sample under the same conditions.

[0090] Combining the above table with Figure 6-8 It can be seen that the photocatalytic CO2 reduction performance of the metal organic framework nanorod clusters / rGO composite material obtained after solid-phase microwave treatment is significantly improved, among which Example 12 has the highest CO yield of 23.11 μmol g -1 h -1 The original one-dimensional MOF structure expanded into nanorod clusters, which were in close contact with rGO. The structural changes caused by solid-phase microwave treatment significantly increased the material's specific surface area and active sites, further enhancing its photocatalytic performance.

[0091] 3. N2 adsorption-desorption isotherms (Micromeritics ASAP2020) were used to analyze the metal-organic framework nanorod cluster / rGO composites and pre-microwave samples prepared in each example and comparative example. The N2 adsorption-desorption isotherms of the samples at 77K were measured. Before testing, approximately 0.10g of test sample was placed in a vacuum pretreatment at 80°C for 6h. The specific surface area of ​​the test sample was calculated according to the Brunauer-Emmet-Tell (BET) equation. The results are as follows:

[0092]

[0093] Among them, such as Figure 3The specific surface area of ​​the metal organic framework nanorod cluster / rGO composite material prepared in Example 3 and the sample before microwave heating is 586.1 m 2 / g, almost before microwave (239.4m 2 / g) is 2.5 times. Figure 3 It was confirmed that the structural changes caused by microwave irradiation significantly increased the specific surface area of ​​the material. The specific surface area of ​​the example sample was greater than that of the comparative example.

[0094] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A method for preparing a metal organic framework nanorod cluster / rGO composite material, characterized in that: The one-dimensional MOF / rGO composite material was placed in a closed reactor and subjected to microwave irradiation in a certain atmosphere to obtain a composite material composed of nanorod clusters of MOF and rGO. MOF materials use metal ions as metal centers and tetrakis(4-carboxyphenyl)porphine (TCPP), terephthalic acid (PTA), 2-aminoterephthalic acid (H2ATA) or trimesic acid (H3BTC) as ligands; During the microwave irradiation process, the microwave power is 50-1200 W and the microwave frequency is 1-15 GHz; The microwave irradiation time is 2-600 s, and the number of irradiation cycles is 1-10 times.

2. The method for preparing a metal organic framework nanorod cluster / rGO composite material according to claim 1, characterized in that: The metal ions include Zr 4+ 、Fe 3+ 、V 4+ 、Bi 3+ 、Ti 4+ 、Zn 2+ 、Co 3+ 、Cu 2+ .

3. The method for preparing a metal organic framework nanorod cluster / rGO composite material according to any one of claims 1-2, characterized in that: The MOF and rGO composite material is prepared by the following method: The ligand is dissolved in a solvent, and metal salt and graphene powder are added. The mixture is stirred and ultrasonicated for 0.5 to 1 hour to form a suspension. The suspension is then transferred to a microwave reactor, heated to 90-180°C, reacted for 0.5-2 hours, cooled to room temperature, centrifuged, washed to obtain a solid product, and dried at 70-90°C to obtain a MOF / rGO composite material with a one-dimensional structure.

4. The method for preparing a metal organic framework nanorod cluster / rGO composite material according to claim 3, characterized in that: The mass ratio of the ligand to the graphene powder is 100:5-40.

5. The method for preparing a metal organic framework nanorod cluster / rGO composite material according to claim 3, characterized in that: The solvent is N,N-dimethylformamide.

6. The method for preparing a metal organic framework nanorod cluster / rGO composite material according to claim 1, characterized in that: The certain atmosphere is air, argon, nitrogen, carbon dioxide or vacuum.

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