Hierarchical porous metal-organic framework material and preparation method thereof

Abstract

The application discloses a kind of hierarchical porous metal organic framework materials and preparation method thereof.The steps are as follows: surfactant, acetic acid, ion auxiliary agent, zirconium salt are added to stirring dissolution, then organic carboxylic acid ligand is added, heating reaction is carried out under the condition of stirring, after reaction is finished, the above product is obtained by washing and drying.The hierarchical porous metal organic framework material prepared by the application has larger mesoporous, larger specific surface area, simple preparation method, is conducive to the transmission of substance and effective use of adsorption site, and can improve the adsorption performance of thorium.

Description

Technical Field

[0001] This invention belongs to the field of materials preparation, specifically relating to a hierarchical porous metal-organic framework material, its preparation method, and its thorium adsorption application. Background Technology

[0002] Metal-organic frameworks (MOFs) are a class of crystalline porous materials with periodic network structures, formed by the covalent self-assembly of inorganic metal centers (metal ions or metal clusters) and organic ligands. Due to their numerous redox active sites, tunable functionality, and large surface area, MOFs hold immense potential in energy storage, catalysis, sensing, drug delivery, and gas separation. However, most MOFs are constructed from metal centers and small organic ligands, resulting in a microporous pore size distribution. This hinders rapid molecular diffusion and mass transport, and also limits the anchoring of large molecular catalysts and the loading of large drug molecules, thus restricting the application of MOFs in the macromolecular field. To meet the ever-growing application demands, extending the pore size of MOFs to the mesoporous range has become a research hotspot.

[0003] Compared to microporous MOFs, mesoporous MOFs possess larger pore sizes and volumes, which facilitates molecular diffusion and the functionalization of complex functional groups, resulting in superior performance compared to microporous MOFs in practical applications. Several methods for preparing mesoporous MOFs have been proposed, including ligand extension, induced defect, and soft template methods. While these methods have made some progress, they still have drawbacks. For example, mesopores obtained by ligand extension are often disordered, and increased pore size typically leads to weaker chemical and thermal stability. Furthermore, long ligands often result in interpenetrating structures, reducing porosity, while induced defect methods lead to uneven pore sizes and random pore distributions. The soft template method is one of the most promising methods for synthesizing mesoporous MOFs, as it not only retains the high specific surface area of ​​micropores but also produces regularly ordered mesopores. However, this method suffers from weak interactions between the template agent and the MOF precursor; therefore, enhancing these interactions is crucial for the synthesis of mesoporous MOFs.

[0004] On the other hand, with the rapid development of nuclear energy, a large amount of radioactive waste will be generated. If this radioactive waste is not properly disposed of and enters the environment, it will pollute soil and water bodies, and harm human health through external and internal radiation, potentially inducing cancer in severe cases. Uranium and thorium are two of the most important radioactive elements. Compared to uranium, thorium is more toxic, and its reserves on Earth are approximately 3-4 times that of uranium. 232Thorium produces fewer long-lived minor actinides, which can meet the world's energy needs for a longer period. Given the hazardous nature of thorium and its importance in nuclear energy, it is crucial to develop an efficient, economical, and rapid method for its separation and recovery. Currently, the main methods for treating thorium-containing radioactive wastewater include chemical precipitation, ion exchange, solvent extraction, adsorption, and membrane separation. Among these, adsorption has received widespread attention due to its advantages such as simple operation, high efficiency, no secondary pollution, and low cost. The key to this method is the development of highly efficient adsorbents with high adsorption capacity, high selectivity, fast adsorption rate, and reusability. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing hierarchical porous metal-organic framework materials by using a surfactant method and its application.

[0006] A hierarchical porous metal-organic framework material and its preparation method, specifically including the following steps: (1) Dissolve the surfactant in water, add acetic acid and ionic additives and stir to dissolve, then stir and add zirconium salt; (2) Add the organic carboxylic acid ligand to the mixed solution formed in step (1), and then carry out the reaction at a constant temperature. (3) After thorough washing, Soxhlet extraction was performed, and after drying, the metal-organic framework material was obtained and named MUiO-66-NH2.

[0007] Furthermore, in step (1), the surfactant is a triblock copolymer F108 (PEO) 132 PPO 50 PEO 132 ).

[0008] Furthermore, in step (1), the ionic additive is one of sodium thiocyanate, sodium iodide, and sodium nitrate.

[0009] Furthermore, in step (1), the zircon salt is zirconium oxychloride octahydrate.

[0010] Furthermore, in step (2), the organic carboxylic acid ligand is 2-aminoterephthalic acid.

[0011] Furthermore, the molar ratio of zirconium salt to organic carboxylic acid ligand is 2:1; the molar ratio of zirconium salt to ionic auxiliaries is 1:2.

[0012] Furthermore, in step (2), the constant temperature reaction temperature is 40℃ and the reaction time is 24 h.

[0013] Furthermore, in step (3), thorough washing means washing three times each with deionized water and N,N-dimethylformamide.

[0014] Furthermore, in step (3), the Soxhlet extraction uses anhydrous ethanol as the extraction agent, the Soxhlet extraction temperature is 100℃, and the extraction time is 48 h.

[0015] Furthermore, the material is in the form of nanospherical particles with a size of 70-200 nm and mesopores with a pore size of 4-20 nm, uniformly distributed across the entire particle surface. The specific surface area of ​​the material is 857.57-963.64 m². 2 / g, pore volume 0.59-0.73 cm³ 3 / g.

[0016] This invention provides an application of hierarchical porous metal-organic framework materials, specifically the application of hierarchical porous metal-organic framework materials for thorium adsorption.

[0017] Furthermore, the adsorption was carried out under strongly acidic conditions at pH=4.

[0018] Furthermore, the hierarchical porous metal-organic framework material was added to a 20 mg / L thorium solution at pH=4 for adsorption. The adsorption temperature was 25℃. After the adsorption was completed, the thorium concentration after adsorption was determined by inductively coupled plasma atomic emission spectrometry.

[0019] Compared with the prior art, the beneficial effects of the present invention are: (1) The material preparation method of the present invention is simple and easy to operate. It does not require reaction under high temperature and high pressure, and has low energy consumption. In addition, deionized water is used instead of traditional organic solvents for synthesis, which reduces costs and also puts into practice the concept of green environmental protection.

[0020] (2) The hierarchical porous metal-organic framework material MUiO-66-NH2 prepared by the present invention is in the form of nanospheres with small particle size. It not only retains the high specific surface area and a large number of adsorption active sites brought by micropores, but also has large mesopores of about 4-20 nm, which are uniformly distributed on the entire particle surface, which is conducive to the transport of substances and enables the active sites to be effectively utilized. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart illustrating the preparation method of the hierarchical porous metal-organic framework material synthesized according to the present invention.

[0023] Figure 2X-ray diffraction comparison diagram of the product obtained according to Example 1 of the present invention.

[0024] Figure 3 The N2 adsorption-desorption isotherm (a) and pore size distribution (b) of the product were obtained according to Example 1 of the present invention.

[0025] Figure 4 Small-angle X-ray scattering pattern of the product obtained according to Example 1 of the present invention.

[0026] Figure 5 The image shown is a scanning electron microscope image of the product obtained according to Example 1 of the present invention.

[0027] Figure 6 X-ray diffraction comparison diagram of the product obtained according to Example 2 of the present invention.

[0028] Figure 7 The N2 adsorption-desorption isotherm (a) and pore size distribution (b) of the product were obtained according to Example 2 of the present invention.

[0029] Figure 8 Small-angle X-ray scattering pattern of the product obtained according to Example 2 of the present invention.

[0030] Figure 9 The image shown is a scanning electron microscope image of the product obtained according to Example 2 of the present invention.

[0031] Figure 10 X-ray diffraction comparison diagram of the product obtained according to Example 3 of the present invention.

[0032] Figure 11 The N2 adsorption-desorption isotherm (a) and pore size distribution (b) of the product were obtained according to Example 3 of the present invention.

[0033] Figure 12 X-ray diffraction comparison diagram of the product obtained according to Example 4 of the present invention.

[0034] Figure 13 The N2 adsorption-desorption isotherm (a) and pore size distribution (b) of the product were obtained according to Example 4 of the present invention.

[0035] Figure 14 The hierarchical porous metal-organic framework material MUiO-66-NH2-I obtained according to Examples 2 and 4 of the present invention - Adsorption kinetics curves of microporous UiO-66-NH2.

[0036] Figure 15 The hierarchical porous metal-organic framework material MUiO-66-NH2-I obtained according to Examples 2 and 4 of the present invention -The pseudo-second-order kinetic fit of microporous UiO-66-NH2.

[0037] Figure 16 The hierarchical porous metal-organic framework material MUiO-66-NH2-I obtained according to Examples 2 and 4 of the present invention - Saturated adsorption curves of microporous UiO-66-NH2.

[0038] Figure 17 The hierarchical porous metal-organic framework material MUiO-66-NH2-I obtained according to Examples 2 and 4 of the present invention - The Langmuir model fitting curve of microporous UiO-66-NH2.

[0039] Figure 18 The hierarchical porous metal-organic framework material MUiO-66-NH2-I obtained according to Example 2 of the present invention - Saturated adsorption curves at different temperatures.

[0040] Figure 19 The hierarchical porous metal-organic framework material MUiO-66-NH2-I obtained according to Example 2 of the present invention - Langmuir model fitting curves at different temperatures. Detailed Implementation

[0041] The embodiments of the present invention will be described in detail below with reference to the examples. Those skilled in the art will understand that the following examples are merely preferred embodiments of the present invention to facilitate a better understanding of the invention, and therefore should not be considered as limiting the scope of the invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention. Unless otherwise specified, the experimental methods in the following examples are conventional methods; the experimental materials used, unless otherwise specified, are all purchased from conventional biochemical reagent manufacturers.

[0042] This invention provides a hierarchical porous metal-organic framework material. The hierarchical porous metal-organic framework material MUiO-66-NH2 is characterized by the coordination between metal clusters formed by zirconium salt and ether bonds on micelles formed by template agent F108, which enables the nucleation and growth of MOFs to grow along the micelles. The addition of ionic additives promotes the embedding of metal clusters into the inner layer of micelles, making the structure more stable. Finally, the template is removed by Soxhlet extraction to obtain ordered mesoporous structures.

[0043] In the following examples, X-ray diffraction patterns were provided by a powder X-ray diffractometer (Bruker D8 Advance); N2 adsorption-desorption isotherms were provided by a multi-station extended fully automated surface area and porosity analyzer (BELSORP-MAX); small-angle X-ray scattering patterns were provided by a small-angle X-ray scattering instrument (Bruker Nanostar); and scanning electron microscopy (SEM) images were obtained using a Zeiss Supra 55 scanning electron microscope.

[0044] like Figure 1 As shown, the method for preparing hierarchical porous metal-organic framework materials synthesized using the surfactant method according to the present invention includes: Step 1: Add the surfactant to the glass bottle, then add deionized water and stir to dissolve.

[0045] Step 2: Add acetic acid and ionic additives to the glass bottle and then stir to mix.

[0046] Step 3: Add the zirconium salt to the glass bottle and stir to dissolve and mix.

[0047] Step 4: Add the organic carboxylic acid ligand to the glass bottle and then carry out the reaction at a constant temperature.

[0048] Step 5: After thorough washing, perform Soxhlet extraction, then dry in an 80℃ oven overnight to obtain the final product MUiO-66-NH2. Example 1

[0049] This invention discloses a method for preparing a hierarchical porous metal-organic framework material, which specifically includes the following steps: Step 1: Weigh 0.1 g of triblock copolymer PEO 132 PPO 50 PEO 132 (F108) was placed in a 15 mL glass bottle, and then 6 mL of deionized water was added. The mixture was stirred and dissolved at room temperature.

[0050] Step 2: Add 0.82 g of acetic acid and 2 mmol of sodium thiocyanate to the solution from Step 1 and mix by stirring at room temperature.

[0051] Step 3: Weigh 0.3222 g (1 mmol) of zirconium oxychloride octahydrate into the mixed solution from Step 2 and stir to dissolve at room temperature.

[0052] Step 4: Weigh 0.09 g (0.5 mmol) of 2-aminoterephthalic acid into the mixed solution from Step 3 and stir at 40 °C for 24 h.

[0053] Step 5: After the reaction was complete, the solid was cooled to room temperature and centrifuged. It was washed three times each with deionized water and DMF. To remove the template agent, anhydrous ethanol was used as the extractant for Soxhlet extraction of the washed solid. Finally, the solid was dried in an oven at 80°C for 24 h to obtain a brownish-yellow powder solid MUiO-66-NH2-SCN. - .

[0054] Figure 2 MUiO-66-NH2-SCN prepared in this embodiment - The X-ray diffraction pattern. (From...) Figure 2 It can be seen that MUiO-66-NH2-SCN - The characteristic X-ray diffraction peaks of the sample are consistent with the simulated X-ray peak positions of UiO-66-NH2, indicating that this method can successfully prepare the metal-organic framework material UiO-66-NH2.

[0055] Figure 3 MUiO-66-NH2-SCN prepared in this embodiment - The N2 adsorption-desorption isotherms and pore size distribution diagrams are shown. From these, we can see that MUiO-66-NH2-SCN... - The N2 adsorption-desorption isotherms are a combination of Type I and Type IV, indicating the simultaneous presence of micropores and mesopores. At lower pressures, all adsorption branches exhibit rapid adsorption and quickly reach saturation, attributed to the presence of micropores. A hysteresis loop exists in the medium-pressure region (0.4-0.7), but it is not significant. However, an approximately H1-type hysteresis loop exists between relative partial pressures of 0.7-0.95. The adsorption branches do not show a significant jump in adsorption capacity but rather a continuous increase, indicating a wide pore size distribution. The pore size distribution diagram shows that MUiO-66-NH2-SCN... - The mesopore size distribution is between 4 and 20 nm, and the specific surface area calculated using the BET method is 857.57 m². 2 / g, pore volume is 0.65 cm³ 3 / g.

[0056] Figure 4 MUiO-66-NH2-SCN prepared in this embodiment - The small-angle X-ray scattering spectrum is shown. The absence of obvious characteristic scattering peaks indicates that the material lacks an ordered mesoporous structure, consistent with the results obtained from the N2 adsorption-desorption isotherms and pore size distribution diagram.

[0057] Figure 5 MUiO-66-NH2-SCN prepared in this embodiment - The scanning electron microscope (SEM) image shows that the material has an approximately spherical morphology, an uneven surface, and small, unevenly distributed particles. Example 2

[0058] This invention discloses a method for preparing a hierarchical porous metal-organic framework material, which specifically includes the following steps: Step 1: Weigh 0.1 g of triblock copolymer PEO 132 PPO 50 PEO 132 (F108) was placed in a 15 mL glass bottle, and then 6 mL of deionized water was added. The mixture was stirred and dissolved at room temperature.

[0059] Step 2: Add 0.82 g of acetic acid and 2 mmol of sodium iodide to the solution from Step 1 and mix by stirring at room temperature.

[0060] Step 3: Weigh 0.3222 g (1 mmol) of zirconium oxychloride octahydrate into the mixed solution from Step 2 and stir to dissolve at room temperature.

[0061] Step 4: Weigh 0.09 g (0.5 mmol) of 2-aminoterephthalic acid into the mixed solution from Step 3 and stir at 40 °C for 24 h.

[0062] Step 5: After the reaction was complete, the solid was cooled to room temperature and centrifuged. It was washed three times each with deionized water and DMF. To remove the template agent, anhydrous ethanol was used as the extractant for Soxhlet extraction of the washed solid. Finally, the solid was dried in an oven at 80°C for 24 h to obtain a brownish-yellow powder solid MUiO-66-NH2-I. - .

[0063] Figure 6 MUiO-66-NH2-I prepared in this embodiment - The X-ray diffraction pattern. (From...) Figure 6 It can be seen that MUiO-66-NH2-I - The characteristic X-ray diffraction peaks of the sample are consistent with the simulated X-ray peak positions of UiO-66-NH2, indicating the successful synthesis of UiO-66-NH2.

[0064] Figure 7 MUiO-66-NH2-I prepared in this embodiment - The N2 adsorption-desorption isotherms and pore size distribution diagrams are shown. From these, we can see that MUiO-66-NH2-I... - The N2 adsorption-desorption isotherms show a distinct H2-type hysteresis loop in the medium-pressure region (0.4-0.8), indicating the presence of cage-like mesopores with small openings. The pore size distribution diagram reveals that MUiO-66-NH2-I... -The mesopore size is 5.84 nm, and the size is relatively uniform. The specific surface area calculated using the BET method is 963.64 m². 2 / g, pore volume is 0.73cm 3 / g.

[0065] Figure 8 MUiO-66-NH2-I prepared in this embodiment - The small-angle X-ray scattering pattern is shown. A relatively obvious scattering peak is observed around 2θ = 0.54°, while a noticeable bulge is present in the 0.8-1° range, indicating that the material possesses a certain degree of ordered mesoporous structure, consistent with the results obtained from the N2 adsorption-desorption isotherms and pore size distribution diagram.

[0066] Figure 9 MUiO-66-NH2-I prepared in this embodiment - The scanning electron microscope (SEM) image shows that the material consists of approximately spherical nanoparticles with a particle size concentrated in the range of 70-200 nm. Ordered mesopores are also visible, uniformly distributed across the entire nanoparticle surface, with a mesopore size of approximately 6 nm, consistent with the pore size distribution results. Example 3

[0067] This invention discloses a method for preparing a hierarchical porous metal-organic framework material, which specifically includes the following steps: Step 1: Weigh 0.1 g of triblock copolymer PEO 132 PPO 50 PEO 132 (F108) was placed in a 15 mL glass bottle, and then 6 mL of deionized water was added. The mixture was stirred and dissolved at room temperature.

[0068] Step 2: Add 0.82 g of acetic acid and 2 mmol of sodium nitrate to the solution from Step 1 and mix by stirring at room temperature.

[0069] Step 3: Weigh 0.3222 g (1 mmol) of zirconium oxychloride octahydrate into the mixed solution from Step 2 and stir to dissolve at room temperature.

[0070] Step 4: Weigh 0.09 g (0.5 mmol) of 2-aminoterephthalic acid into the mixed solution from Step 3 and stir at 40 °C for 24 h.

[0071] Step 5: After the reaction was complete, the solid was cooled to room temperature and centrifuged. It was washed three times each with deionized water and DMF. To remove the template agent, anhydrous ethanol was used as the extractant for Soxhlet extraction of the washed solid. Finally, the solid was dried in an oven at 80°C for 24 h to obtain a brownish-yellow powder solid MUiO-66-NH2-NO3. -.

[0072] Figure 10 MUiO-66-NH2-NO3 prepared in this embodiment - The X-ray diffraction pattern. (From...) Figure 10 It can be seen that MUiO-66-NH2-NO3 - The characteristic X-ray diffraction peaks of the sample are consistent with the simulated X-ray peak positions of UiO-66-NH2, indicating the successful synthesis of UiO-66-NH2.

[0073] Figure 11 MUiO-66-NH2-NO3 prepared in this embodiment - Isotherms and pore size distribution diagrams of N2 adsorption-desorption. MUiO-66-NH2-NO3 - The isotherm in the medium-pressure region shows no hysteresis loop and no sudden increase in adsorption, indicating that F108 did not act as a micellar template. The hysteresis loop appearing between 0.8 and 1.0 relative pressures is attributed to interstitial pores formed by particle aggregation. The pore size distribution diagram also shows the absence of obvious mesopores, indicating that NO3... - It cannot enhance the interaction between surfactants and MOF precursors. Example 4

[0074] This invention discloses a method for preparing a microporous metal-organic framework material, specifically comprising the following steps: Step 1: Add 0.134 g of 2-aminoterephthalic acid (BDC-NH2) and 10 mL of DMF to a glass bottle and dissolve by sonication.

[0075] Step 2: Add 0.125 g zirconium tetrachloride (ZrCl4), 5 mL DMF and 1 mL concentrated hydrochloric acid to another glass bottle, and dissolve by sonication.

[0076] Step 3: Add the mixed solution from Step 2 to the mixed solution from Step 1, and sonicate for 20 minutes to ensure the solution is thoroughly mixed.

[0077] Step 4: Transfer the mixed solution to a 20 mL polytetrafluoroethylene liner, place it in the reaction vessel, and then place it in an 80 °C oven for 24 h.

[0078] Step 5: The obtained solid was separated by centrifugation, then washed three times each with DMF and anhydrous ethanol, and finally dried overnight in an 80℃ oven to obtain brownish-yellow UiO-66-NH2.

[0079] Figure 12 The X-ray diffraction pattern of UiO-66-NH2 prepared in this embodiment is shown. Figure 12It can be seen that the characteristic X-ray diffraction peaks of UiO-66-NH2 are consistent with the simulated X-ray peak positions of UiO-66-NH2, indicating the successful synthesis of UiO-66-NH2.

[0080] Figure 13 The N2 adsorption-desorption isotherms and pore size distribution diagrams for UiO-66-NH2 prepared in this embodiment are shown. The N2 adsorption-desorption isotherms of UiO-66-NH2 are Type I, indicating its microporous properties, and its specific surface area is 850.52 m². 2 / g, pore volume 0.42cm 3 / g, as can be seen from the pore size distribution diagram, it has three micropore sizes of 0.45 nm, 1.01 nm and 1.89 nm, and no obvious mesopores exist.

[0081] In summary, by comparing Examples 1, 2, and 3, it is shown that this method can successfully synthesize the metal-organic framework material UiO-66-NH2. The presence of triblock copolymers and ions has no effect on the structure of the material, but there are differences in the formation of mesopores. (SCN) - and I - Both can promote the formation of hierarchical porous structures. The former lacks an ordered mesoporous structure, while the latter's mesoporous structure has a certain degree of order. NO3 - It has no significant effect on the formation of hierarchical porous structures. By comparing Examples 2 and 4, the hierarchical porous metal-organic framework material MUiO-66-NH2-I synthesized by this method... - Its specific surface area, pore volume, and pore size are all higher than those of microporous UiO-66-NH2.

[0082] The hierarchical porous metal-organic framework material MUiO-66-NH2-I synthesized above using the surfactant method and hydrothermal method - Due to its mesopore size of approximately 6 nm, it facilitates material transport and efficient utilization of adsorption active sites, demonstrating significant potential in the treatment of radioactive wastewater. In a solution with pH=4, its equilibrium adsorption capacity and maximum adsorption capacity for thorium reached 59.84 mg / g and 174.82 mg / g, respectively, both higher than those of the microporous UiO-66-NH2. Mechanistic studies indicate that the adsorption process is a spontaneous monolayer chemisorption. Therefore, this material can serve as a candidate for treating thorium-containing radioactive wastewater, preventing thorium from entering the environment and causing harm to ecology and human health.

[0083] The applicant declares that the present invention is illustrated through the above embodiments to demonstrate its detailed features and methods, but the present invention is not limited to the above detailed features and methods, that is, it does not mean that the present invention must rely on the above detailed features and methods to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the components used in the present invention, addition of auxiliary components, selection of specific methods, and other changes made within the scope of knowledge possessed by those skilled in the art, without departing from the spirit of the present invention, all fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a hierarchical porous metal-organic framework material for thorium ion adsorption, characterized in that, Specifically, the following steps are included: (1) Dissolve the surfactant in water, add acetic acid and ionic additives and stir to dissolve, then stir and add zirconium salt; (2) Add the organic carboxylic acid ligand to the mixed solution formed in step (1), and then carry out the reaction at a constant temperature. (3) After thorough washing, Soxhlet extraction was performed, and the metal-organic framework material was obtained after drying and named MUiO-66-NH 2； The surfactant is a triblock copolymer PEO. 132 PPO 50 PEO 132 The ionic additive is one of sodium thiocyanate or sodium iodide.

2. The method as described in claim 1, characterized in that, The zirconium salt is zirconium oxychloride octahydrate; the organic carboxylic acid ligand is 2-aminoterephthalic acid.

3. The method as described in claim 1, characterized in that, The molar ratio of zirconium salt to organic carboxylic acid ligand is 2:1; the molar ratio of zirconium salt to ionic auxiliaries is 1:

2.

4. The method as described in claim 1, characterized in that, In step (2), the constant temperature reaction temperature is 40℃ and the reaction time is 24 h.

5. The method as described in claim 1, characterized in that, In step (3), thorough washing means washing three times each with deionized water and N,N-dimethylformamide.

6. The method as described in claim 1, characterized in that, In step (3), the Soxhlet extraction uses anhydrous ethanol as the extractant, the Soxhlet extraction temperature is 100℃, and the extraction time is 48 h.

7. The hierarchical porous metal-organic framework material prepared by the method according to any one of claims 1-6.

8. The hierarchical porous metal-organic framework material as described in claim 7, characterized in that, The material is in the form of nanospheres with a size of 70-200 nm and mesopores with a pore size of 4-20 nm, which are uniformly distributed across the entire particle surface.

9. The hierarchical porous metal-organic framework material as described in claim 7, characterized in that, The specific surface area of ​​the material is 857.57-963.64 m². 2 / g, pore volume 0.59-0.73 cm³ 3 / g.

10. The application of hierarchical porous metal-organic framework materials prepared by any one of claims 1-6 in thorium ion adsorption.

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