A pyrazole organic monomer, a preparation method thereof, a three-dimensional MOF material and application thereof

Abstract

This invention discloses a pyrazole organic monomer and its preparation method, as well as three-dimensional MOF materials and their applications, belonging to the field of organic synthesis technology. This invention is the first to synthesize a novel pyrazole organic monomer compound and, through a solvothermal method, synthesizes three-dimensional Ni-MOF, Zn-MOF, Mn-MOF, Co-MOF, or Fe-MOF based on this novel pyrazole organic monomer compound. Since Ni-MOF, Zn-MOF, Mn-MOF, Co-MOF, or Fe-MOF can generate reactive oxygen species, Ni-MOF materials can simultaneously remove heavy metals and organic pollutants from water. Furthermore, Ni-MOF, Zn-MOF, Mn-MOF, Co-MOF, or Fe-MOF materials can act as activators for PMS or H2O2 to degrade pollutants. In addition, the five MOF materials exhibit excellent structural and performance stability, anti-interference properties, and recyclability, demonstrating broad applicability to various pollutants.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a pyrazole organic monomer and its preparation method, and three-dimensional MOF materials and their applications. Background Technology

[0002] In recent years, with the acceleration of industrialization and the development of the chemical industry, new pollutants (such as microplastics, persistent organic pollutants, and heavy metal ions) have had an increasingly significant impact on the environment, posing a serious threat to ecosystems and human health. Traditional wastewater treatment technologies, such as biodegradation, adsorption, and chemical oxidation, can remove some pollutants to a certain extent, but they suffer from problems such as low efficiency, high cost, and secondary pollution. Especially when dealing with complex and trace amounts of new pollutants, their effectiveness is often unsatisfactory.

[0003] Metal-organic frameworks (MOFs), as a novel class of porous materials, have shown great potential in gas storage, separation, and catalysis due to their high specific surface area, tunable pore structure, and ease of functional modification. Especially in environmental pollution control, MOFs, with their unique structure and functional diversity, are expected to be an effective means of efficiently removing and transforming new pollutants. However, current MOF materials still face some challenges in practical applications, including but not limited to: 1. Insufficient catalytic activity and universality: The activity and selectivity of existing MOF materials in catalytically degrading new pollutants are often limited by the design of the organic ligands and the selection of the metal nodes, making it difficult to achieve efficient degradation of multiple pollutants. 2. Stability issues: In actual wastewater treatment environments, MOFs may face extreme conditions such as changes in pH, high temperature, and high salinity, leading to structural damage or functional failure. 3. Difficulty in recycling and reuse: After use, MOF materials, due to their complex structure, are often difficult to effectively recycle and regenerate, increasing treatment costs and environmental burden.

[0004] To improve the catalytic efficiency, versatility, stability, and regeneration performance of MOFs, special polypyrazole organic ligand structures are designed to enhance the electron transfer capacity and accessibility of reaction sites in MOF materials. This aims to achieve higher catalytic activity and selective degradation of multiple target pollutants simultaneously, while maintaining structural stability in complex environments, extending service life, and reducing maintenance and replacement frequency. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a pyrazole organic monomer and its preparation method, as well as a three-dimensional MOF material and its applications. This invention synthesizes a novel pyrazole organic monomer and uses it as a ligand for three-dimensional MOF materials to synthesize Ni-MOF, Zn-MOF, Mn-MOF, Co-MOF, or Fe-MOF metal-organic framework materials. The Ni-MOF metal-organic framework material can simultaneously remove multiple pollutants and heavy metal ions from water, while the Ni-MOF, Zn-MOF, Mn-MOF, Co-MOF, or Fe-MOF metal-organic framework materials can activate PMS or H2O2 to remove organic pollutants from water.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The structural formula of a pyrazole organic monomer is as follows:

[0008] .

[0009] The method for preparing the pyrazole organic monomer includes the following steps:

[0010] (1) First, 1,3,6,8-tetrabromopyrene, 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester, tetrabutylammonium bromide and tetra(triphenylphosphine)palladium are added to alkaline organic solvent A and stirred or sonicated under an inert gas atmosphere.

[0011] (2) After heating and refluxing in an inert gas atmosphere and cooling to room temperature, the mixture is subjected to rotary evaporation, extraction, and rotary evaporation. Then, alcohol and acid A are added and sonicated. Finally, the mixture is stirred until the acidification reaction is complete to obtain a suspension.

[0012] (3) After adjusting the pH to 7 by pouring the suspension into water, the precipitate was obtained, washed, and dried to obtain the pyrazole organic monomer.

[0013] In a preferred embodiment of the present invention, the molar ratio of 1,3,6,8-tetrabromopyrene and 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester is 1:(4-8); the molar ratio of 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester to tetrabutylammonium bromide is (15-30):1; the molar ratio of 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester to tetra(triphenylphosphine)palladium is (60-120):1; the organic solvent A is toluene or xylene; the base in the alkaline organic solvent A is an aqueous solution of potassium carbonate, and the concentration of the aqueous solution of potassium carbonate is 0.5 g / mL-1.5 g / mg.

[0014] This invention enhances the solubility of the substrate by using toluene or xylene, which facilitates contact between reactants, improves reaction selectivity and yield, and suppresses side reactions.

[0015] In a preferred embodiment of the present invention, in step (2), the alcohol is methanol or ethanol, and acid A is nitric acid, hydrochloric acid or sulfuric acid; the acidification reaction time is 4-8 h; the extract used in the extraction is a mixture of solvent and water, the solvent is dichloromethane or dichloroethane, and the volume ratio of solvent to water is 1:(0.5-1); the reflux temperature is 100-135℃, the time is 24-72 h, and the heating method is oil bath or sand bath.

[0016] In a preferred embodiment of the present invention, in step (3), the volume ratio of the suspension to water is 1:(5-10), and more preferably, the volume ratio of the suspension to water is 1:(8-10).

[0017] A three-dimensional MOF material, comprising Ni-MOF metal-organic framework material, Zn-MOF metal-organic framework material, Mn-MOF metal-organic framework material, Co-MOF metal-organic framework material or Fe-MOF metal-organic framework material, prepared by a solvothermal method using the pyrazole organic monomer as a ligand and nickel salt, zinc salt, manganese salt, cobalt salt or iron salt as metal salt.

[0018] As a preferred embodiment of the present invention, the preparation method of the three-dimensional MOF material, when the metal salt is a nickel salt, includes the following steps: dissolving the pyrazole organic monomer in organic solvent B, and then adding methanol, dimethyl sulfoxide, acid B and nickel salt solution and ultrasonically obtaining Ni-MOF;

[0019] When the metal salt is a zinc salt, the following steps are included: dissolving the pyrazole organic monomer in organic solvent B, then adding methanol, dimethyl sulfoxide, acid C and zinc salt solution and sonicating to obtain Zn-MOF;

[0020] When the metal salt is a manganese salt, the following steps are included: dissolving the pyrazole organic monomer in organic solvent B, and then adding methanol, water, acid B and manganese salt solution and sonicating to obtain Mn-MOF;

[0021] When the metal salt is a cobalt salt, the following steps are included: dissolving the pyrazole organic monomer in organic solvent B, then adding methanol, dimethyl sulfoxide, acid C and cobalt salt solution and sonicating to obtain Co-MOF;

[0022] When the metal salt is an iron salt, the following steps are included: dissolving the pyrazole organic monomer in an organic solvent, then adding acetonitrile, dimethyl sulfoxide, acid B and iron salt solution, sonicating, and heating to react and obtain Fe-MOF.

[0023] The three-dimensional MOF materials prepared by the method are single-crystal materials with well-defined structures.

[0024] In a preferred embodiment of the present invention, the organic solvent B is dimethyl sulfoxide, N,N-dimethylformamide, or N,N-dimethylacetamide; the concentration of the pyrazole organic monomer in the organic solvent B is 5-20 mg / mL; the acid B is glacial acetic acid, and the acid C is 10% sulfuric acid; the volume ratio of methanol, dimethyl sulfoxide, acid B, and nickel salt solution is 10:(5-10):(0.7-1):(0.1-0.2); the volume ratio of methanol, dimethyl sulfoxide, acid C, and zinc salt solution is 10:(5-10):(0.7-1):(0.1-0.2); the volume ratio of methanol, dimethyl sulfoxide, acid C, and cobalt salt solution is 10:(5-10):(0.7-1):(0.1-0.2). The concentration of nickel salt solution, zinc salt solution or cobalt salt solution is 0.02 g / mL; the volume ratio of methanol, water, acid B and manganese salt solution is 10:(2-4):(0.7-1):(0.1-0.2); the concentration of manganese salt solution is 0.02 g / mL; the volume ratio of acetonitrile, dimethyl sulfoxide, acid B and iron salt solution is 10:(2-5):(0.7-1):(0.1-0.2); the concentration of iron salt solution is 0.02 g / mL.

[0025] In a preferred embodiment of the present invention, the heating reaction temperature is 100-140°C, the time is 12-56 hours, the heating rate is 10-20°C / hour, and the cooling rate is 5-10°C / hour; more preferably, the heating reaction temperature is 120-140°C.

[0026] This invention also claims protection for the use of the Ni-MOF metal-organic framework material in the removal of heavy metal ions and / or organic pollutants from wastewater.

[0027] This invention also claims protection for the use of the three-dimensional MOF material in activating PMS or H2O2 to remove organic pollutants from water.

[0028] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention synthesizes novel pyrazole organic monomer compounds for the first time, and synthesizes three-dimensional Ni-MOF, Zn-MOF, Mn-MOF, Co-MOF, or Fe-MOF materials based on these novel pyrazole organic monomer compounds using a solvothermal method. Since the three-dimensional MOF materials can generate reactive oxygen species, Ni-MOF materials can simultaneously remove heavy metals and organic pollutants from water. Furthermore, the three-dimensional MOF materials can act as activators for PMS or H2O2 to degrade pollutants. In addition, the five MOF materials exhibit excellent structural and performance stability, anti-interference properties, and recyclability, and are universally applicable to various pollutants. Attached Figure Description

[0029] Figure 1 This is the mass spectrum of the pyrazole organic monomer.

[0030] Figure 2 The crystal structure diagrams of three-dimensional Ni-MOF materials are shown below: a) Coordination environment of Ni(II) in Ni-MOF, b) Two-dimensional structure of Ni-MOF, and c) Three-dimensional structure of Ni-MOF.

[0031] Figure 3 The crystal structure diagrams of three-dimensional Fe-MOF materials are shown below: a) Coordination environment of Fe(II) in Fe-MOF, b) Three-dimensional structure of Fe-MOF - a-axis, c) Three-dimensional structure of Fe-MOF - b-axis, d) Three-dimensional structure of Fe-MOF - c-axis.

[0032] Figure 4 SEM images of the materials prepared in Examples 1 and 3-4. a) SEM image of the pyrazole organic monomer prepared in Example 1; b) SEM image of the three-dimensional Ni-MOF material prepared in Example 3; c) SEM image of the three-dimensional Fe-MOF material prepared in Example 4.

[0033] Figure 5 The images show the XRD patterns of Example 1, Example 3, and the single-crystal simulated Ni-MOF material.

[0034] Figure 6 The images show the XRD patterns of Examples 2 and 4, as well as the single-crystal simulated Fe-MOF material.

[0035] Figure 7 The graph shows the removal performance of Ni-MOF prepared in Example 3 for various heavy metal ions in a mixed heavy metal system.

[0036] Figure 8 The adsorption isotherm of Hg(II) on Ni-MOF prepared in Example 3 is shown.

[0037] Figure 9 The graph shows the performance of Ni-MOF prepared in Example 3 in removing Hg(II) and organic pollutants simultaneously under different water environments.

[0038] Figure 10 The graphs show the catalytic degradation effects of Fe-MOF-activated H2O2 or PMS on tetracycline prepared in Example 4; a) is the catalytic degradation graph; b) is the kinetic curve graph.

[0039] Figure 11 a) shows the degradation effect of Ni-MOF prepared in Example 3 on four organic pollutants; b) shows the degradation effect of Ni-MOF-induced PMS prepared in Example 3 on four organic pollutants.

[0040] Figure 12The effect of Fe-MOF activating H2O2 or PMS on the degradation of different organic pollutants in Dianchi Lake water in Kunming, Yunnan. Detailed Implementation

[0041] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. Example

[0042] A method for preparing a pyrazole organic monomer includes the following steps:

[0043] (1) First, under an inert gas atmosphere, 4 mmol of 1,3,6,8-tetrabromopyrene was added to 140 mL of toluene and stirred at room temperature for 5 minutes. Then, 25 mmol of 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester, 0.8 g of tetrabutylammonium bromide, 150 mg of tetra(triphenylphosphine)palladium and 20 mL of 0.5 g / mL potassium carbonate solution were added to the reaction mixture and stirred.

[0044] (2) After refluxing at 100°C for 48 hours in an inert gas atmosphere and cooling to room temperature, the solution was rotary evaporated under pressure at 130°C. After rotary evaporation and cooling to room temperature, 100 mL of dichloromethane was added for dilution. The diluted solution was poured into a separatory funnel, 100 mL of water was added, shaken, and allowed to stand for 5 min to remove unreacted metal catalysts and soluble impurities. The lower layer of the solution was transferred from the separatory funnel to a round-bottom flask and subjected to a second rotary evaporation (60 r / min, 40°C, under pressure). 100 mL of ethanol solution was added to the concentrate after rotary evaporation, followed by 20 mL of nitric acid and sonication for 30 min to form an orange-yellow suspension.

[0045] (3) Pour 20 mL of orange-yellow suspension into 200 mL of water, adjust the pH to 7 with 0.1 mol of sodium hydroxide to obtain a precipitate, wash with water 3 times, and dry to obtain pyrazole organic monomer. Example

[0046] A method for preparing a pyrazole organic monomer includes the following steps:

[0047] (1) First, under an inert gas atmosphere, 10 mmol of 1,3,6,8-tetrabromopyrene was added to 120 mL of xylene and stirred at room temperature for 2 minutes. Then, 55 mmol of 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester, 0.6 g of tetrabutylammonium bromide, 120 mg of tetra(triphenylphosphine)palladium and 15 mL of 0.5 g / mL potassium carbonate solution were added to the reaction mixture and stirred.

[0048] (2) After refluxing at 120°C for 48 hours in an inert gas atmosphere and cooling to room temperature, the solution was rotary evaporated under pressure at 150°C. After rotary evaporation and cooling to room temperature, 120 mL of dichloromethane was added for dilution. The diluted solution was poured into a separatory funnel, 140 mL of water was added, and the mixture was shaken and allowed to stand for 5 min to remove unreacted metal catalysts and soluble impurities. The lower layer of the solution was transferred from the separatory funnel to a round-bottom flask and subjected to a second rotary evaporation (60 r / min, 80°C, under pressure). 100 mL of ethanol solution was added to the concentrate after rotary evaporation, followed by 20 mL of nitric acid and sonication for 30 min to form an orange-yellow suspension.

[0049] (3) Pour 20 mL of orange-yellow suspension into 200 mL of water, adjust the pH to 7 with 0.1 mol of sodium hydroxide to obtain a precipitate, wash with water 3 times, and dry to obtain pyrazole organic monomer.

[0050] The mass spectra of the pyrazole organic monomers prepared in Examples 1 and 2 are as follows: Figure 1 As shown. According to Figure 1 It can be seen that the pyrazole organic monomer was successfully prepared, and its structural formula is as follows:

[0051] . Example

[0052] A method for preparing a three-dimensional Ni-MOF includes the following steps: The pyrazole organic monomer prepared in Example 1 is dissolved in N,N-dimethylformamide to a concentration of 5 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the solution is taken, and 1 mL of methanol, 0.8 mL of dimethyl sulfoxide, 0.1 mL of glacial acetic acid, and 0.1 mL of 0.02 g / mL nickel nitrate are added sequentially. The mixture is sonicated for 10 min, then reacted at 120 °C for 56 h at a heating rate of 20 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Ni-MOF material.

[0053] A method for preparing a three-dimensional Zn-MOF includes the following steps: The pyrazole organic monomer prepared in Example 1 is dissolved in N,N-dimethylformamide to a concentration of 5 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the above solution is taken, and 1 mL of methanol, 0.8 mL of dimethyl sulfoxide, 0.1 mL of 0.1 mL of sulfuric acid, and 0.1 mL of 0.02 g / mL zinc nitrate are added sequentially. The mixture is sonicated for 10 min, then reacted at 120 °C for 56 h at a heating rate of 20 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Zn-MOF material.

[0054] A method for preparing a three-dimensional Co-MOF includes the following steps: The pyrazole organic monomer prepared in Example 1 is dissolved in N,N-dimethylformamide to a concentration of 5 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the above solution is taken, and 1 mL of methanol, 0.8 mL of dimethyl sulfoxide, 0.1 mL of glacial acetic acid (0.1 mL of sulfuric acid), and 0.1 mL of 0.02 g / mL cobalt nitrate are added sequentially. The mixture is sonicated for 10 min, then reacted at 120 °C for 56 h at a heating rate of 20 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Co-MOF material.

[0055] A method for preparing a three-dimensional Mn-MOF material includes the following steps: The pyrazole organic monomer prepared in Example 1 is dissolved in N,N-dimethylformamide to a concentration of 5 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the solution is taken, and 1 mL of methanol, 0.4 mL of water, 0.1 mL of glacial acetic acid, and 0.1 mL of 0.02 g / mL manganese sulfate are added sequentially. The mixture is sonicated for 5 min, then reacted at 140 °C for 48 h at a heating rate of 20 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Mn-MOF material.

[0056] A method for preparing a three-dimensional Fe-MOF material includes the following steps: The pyrazole organic monomer prepared in Example 1 is dissolved in N,N-dimethylformamide to a concentration of 5 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the solution is taken, and 1 mL of acetonitrile, 0.4 mL of dimethyl sulfoxide, 0.1 mL of glacial acetic acid, and 0.1 mL of 0.02 g / mL ferrous sulfate are added sequentially. The mixture is sonicated for 5 min, then reacted at 140 °C for 56 h at a heating rate of 20 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Fe-MOF material. Example

[0057] A method for preparing a three-dimensional Ni-MOF includes the following steps: The pyrazole organic monomer prepared in Example 2 is dissolved in N,N-dimethylformamide to a concentration of 20 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the solution is taken, and 1 mL of methanol, 0.5 mL of dimethyl sulfoxide, 0.07 mL of glacial acetic acid, and 0.2 mL of 0.02 g / mL nickel nitrate are added sequentially. The mixture is sonicated for 10 min, then reacted at 140 °C for 12 h at a heating rate of 10 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Ni-MOF material.

[0058] A method for preparing a three-dimensional Zn-MOF includes the following steps: The pyrazole organic monomer prepared in Example 2 is dissolved in N,N-dimethylformamide to a concentration of 20 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the solution is taken, and 1 mL of methanol, 1 mL of dimethyl sulfoxide, 0.08 mL of 0.1 mL of sulfuric acid, and 0.1 mL of 0.02 g / mL zinc nitrate are added sequentially. The mixture is sonicated for 10 min, then reacted at 100 °C for 24 h at a heating rate of 15 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Zn-MOF material.

[0059] A method for preparing a three-dimensional Co-MOF includes the following steps: The pyrazole organic monomer prepared in Example 2 is dissolved in N,N-dimethylformamide to a concentration of 5 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the solution is taken, and 1 mL of methanol, 0.8 mL of dimethyl sulfoxide, 0.1 mL of glacial acetic acid (0.1 mL of sulfuric acid), and 0.1 mL of 0.02 g / mL cobalt nitrate are added sequentially. The mixture is sonicated for 10 min, then reacted at 120 °C for 56 h at a heating rate of 20 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Co-MOF material.

[0060] A method for preparing a three-dimensional Mn-MOF material includes the following steps: The pyrazole organic monomer prepared in Example 2 is dissolved in N,N-dimethylformamide to a concentration of 20 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the solution is taken, and 1 mL of methanol, 0.4 mL of water, 0.1 mL of glacial acetic acid, and 0.1 mL of 0.02 g / mL manganese sulfate are added sequentially. The mixture is sonicated for 5 min, then reacted at 120 °C for 12 h at a heating rate of 20 °C / h, and then cooled to room temperature at a cooling rate of 5 °C / h to obtain the three-dimensional Mn-MOF material.

[0061] A method for preparing a three-dimensional Fe-MOF material includes the following steps: The pyrazole organic monomer prepared in Example 2 is dissolved in N,N-dimethylformamide to a concentration of 10 mg / mL, and the solution is sonicated for 5 min. 0.2 mL of the solution is taken, and 1 mL of acetonitrile, 0.4 mL of dimethyl sulfoxide, 0.1 mL of glacial acetic acid, and 0.1 mL of 0.02 g / mL ferrous sulfate are added sequentially. The mixture is sonicated for 5 min, then reacted at 120 °C for 12 h at a heating rate of 20 °C / h, and then cooled to room temperature at a cooling rate of 10 °C / h to obtain the three-dimensional Fe-MOF material.

[0062] The crystal structures of the Ni-MOF and Fe-MOF metal-organic frameworks synthesized in Examples 3 and 4 are as follows: Figure 2 and 3As shown, the scanning electron microscope image is as follows: Figure 4 .according to Figure 5 and 6 XRD analysis revealed that, based on the simulated XRD pattern of Ni-MOF using the single-crystal structure, the synthesized Ni-MOF powder exhibited distinct peaks at 8.98°, 10.58°, 14.58°, 18.04°, 22.16°, and 24.02°. Furthermore, the simulated XRD pattern of Fe-MOF using the single-crystal structure showed distinct peaks at 9.04°, 10.48°, 14.76°, 18.34°, 20.56°, and 22.40°, indicating that both the synthesized Ni-MOF and Fe-MOF powders possess high crystallinity.

[0063] Example of effect 1

[0064] Test samples: Comparison of MOF (Ni-MOF two-dimensional structure) materials and materials prepared in Examples 1-4.

[0065] The preparation method of the comparative MOF includes the following steps: A method for preparing a two-dimensional Ni-MOF material includes the following steps: The pyrazole organic monomer prepared in Example 1 is dissolved in N,N-dimethylformamide to prepare a solution with a concentration of 10 mg / mL, and sonicated for 5 min. 0.2 mL of the above solution is taken, and 1 mL of methanol, 0.1 mL of glacial acetic acid, and 0.1 mL of 0.02 g / mL nickel nitrate are added sequentially, and the mixture is sonicated for 10 min to obtain the comparative MOF material, which has a two-dimensional structure.

[0066] The method for ICP determination of test samples with different metal ion contents is as follows:

[0067] To prepare a 150 mg / L metal salt: Weigh Hg(NO3)2 and Pb(NO3)2 and add them to 100 mL volumetric flasks respectively. Dilute to volume with 0.01 mol / L HEPES buffer solution (pH=7.4), and sonicate until the metal salts are completely dissolved to obtain a metal cation stock solution with a concentration of 150 mg / L.

[0068] Add 10 mg of the test sample to each of the above 50 mL metal ion solutions, shake for 24 hours, and then filter using a 0.45 μm filter. Collect the adsorbed filtrate in centrifuge tubes and analyze the ion concentration using ICP-AES.

[0069] Recyclability testing of materials after adsorption of metal ions:

[0070] The test sample after adsorption of heavy metal ions was added to deionized water with pH 3-4, and then 10% thiourea was added and stirred for 3 hours to desorb the heavy metal ions. The sample was then dried to obtain the dried adsorbent material. The above adsorption process for removing different metal ions was repeated 5 times. The adsorption rate and desorption rate of the adsorbent material prepared in Example 3 for Hg(II) are shown in Table 1.

[0071]

[0072] Because Ni-MOF has a large number of uncoordinated N atoms, it can adsorb Hg(II) to form Hg-N bonds. Therefore, Ni-MOF material has a good removal effect on Hg(II) and Pb(II), with Hg(II) removal reaching more than 95% and Pb(II) removal reaching more than 75%. Furthermore, as shown in Table 1, Ni-MOF has good recyclability for heavy metal adsorption.

[0073] The pyrazole organic monomers prepared in Examples 1 and 2 achieved a removal rate of 40% for Hg(II) and 30% for Pb(II), while the adsorption rate of the MOF material for Pb(II) and Hg(II) was less than 5%, and the resolution was too low to be detected.

[0074] The Fe-MOF, Zn-MOF, Mn-MOF, and Co-MOF materials prepared in Examples 3 and 4 did not have a removal effect on Hg(II) and Pb(II).

[0075] Example 2

[0076] Test sample: Ni-MOF material prepared in Example 3.

[0077] The adsorption interference experiment of the Ni-MOF prepared in Example 3 was performed as follows: solutions of Hg(II), Pb(II), Cd(II), Cr(II), Co(II), Ni(II), Ca(II), K(I), Na(I), and Mg(II) metal ions were mixed. The concentration of each of the 10 metal ions was maintained at 120 mg / L, and 10 mg of Ni-MOF or Fe-MOF was added. After shaking for 24 hours, the mixture was filtered using a filter with a pore size of 0.45 μm. The adsorbed filtrate was collected in centrifuge tubes, and the ion concentration was analyzed using ICP-AES.

[0078] like Figure 7 As shown, Ni-MOF materials exhibit selective adsorption of Hg(II) and are unaffected by other ions.

[0079] Example 3

[0080] When the initial concentration of Hg(II) was set at 14 points between 4 and 685 mg / L (4.079, 4.206, 15.26, 36.57, 136.8, 240.6, 136.8, 240.6, 340.6, 421.19, 492.76, 537.53, 586.25, 685.15 mg / L), 10 mg of Ni-MOF was added to each point, and the mixture was shaken for 24 hours. The mixture was then filtered using a 0.45 μm filter. The adsorbed filtrate was collected in centrifuge tubes, and the ion concentration was analyzed using ICP-AES to measure the maximum adsorption capacity of the Ni-MOF prepared in Example 3 for Hg(II). Figure 8 It can be seen that the maximum adsorption capacity of Ni-MOF was determined to be 948 mg / g through adsorption experiments.

[0081] Example of effect 4

[0082] 50 mg of the Ni-MOF or comparative MOF prepared in Example 3 was added to 50 mL of pure water, tap water, or lake water containing Hg(II) (150 mg / L), tetracycline TC (18 mg / L), 17α-ethynylestradiol EE2 (3 mg / L), rhodamine B RhB (18 mg / L), and methylene blue MB (12 mg / L). The solution was shaken at 25°C for 6 hours and then filtered using a 0.45 μm filter. The adsorbed filtrate was collected in centrifuge tubes, and the absorbance was measured using UV-Vis spectroscopy. The corresponding concentrations were calculated according to the corresponding standard curves (EE2 was quantified using liquid chromatography-mass spectrometry, and the Hg(II) content was analyzed using ICP-AES).

[0083] The results are as follows Figure 9 As shown, the Ni-MOF prepared in Example 3 has excellent degradation effects on all pollutants and is not affected by the complex environment of actual wastewater, such as extreme conditions such as changes in pH, high temperature, and high salinity.

[0084] Compared with MOF materials, which cannot effectively remove heavy metal ions and organic pollutants at the same time, their adsorption of Hg(II) and Pb(II) and degradation of the above-mentioned organic substances are both less than 20%.

[0085] After adsorbing heavy metal ions and organic pollutants, Ni-MOF was added to deionized water with pH=3-4, and then thiourea with a volume percentage of 10% was added and stirred for 3 hours to desorb the heavy metal ions before drying.

[0086] The dried material was then soaked in ethanol for 30 minutes and then dried to obtain the dried adsorbent material. The dried material still has a good removal rate for heavy metals and various organic pollutants, so the Ni-MOF has good recyclability.

[0087] Example 5

[0088] Five 50 mL containers were prepared, and 50 mL of a tetracycline (40 mg / L) aqueous solution was added to each. Then, one container was filled with only 10 mg of the Fe-MOF prepared in Example 3, one with only 5 μM H2O2, one with only 0.5 μM PMS, one with both 10 mg of the Fe-MOF prepared in Example 3 and 5 μM H2O2, and one with both 10 mg of the Fe-MOF prepared in Example 3 and 0.5 μM PMS. The five reactions were shaken for 30 minutes, and samples were taken at predetermined time intervals and filtered using a 0.45 μm filter. The adsorbed filtrate was collected in centrifuge tubes, and the TC content was determined by liquid chromatography. The test method was as follows: Column: C18 column (Hypersil GOLD), 100 mm * 2.1 mm, packing particle size 1.9 μm, column temperature 27.5 °C. Gradient elution: flow rate 0.3 mL / min. From 0 to 3 minutes, methanol:water (0.1% formic acid) = 5:95; from 3 to 8 minutes, methanol:water (0.1% formic acid) = 95:5; from 8 to 10 minutes, methanol:water (0.1% formic acid) = 5:95. Ion source: HESI, ion source temperature 300℃, spray voltage 3.5kV. Mass spectrometry mode: high-resolution FTMS mode, resolution 60,000, positive ion acquisition, mass-to-nucleus ratio range 100~500.

[0089] like Figure 10 It can be seen that Fe-MOF can effectively activate H2O2 and PMS, and the degradation rate of TC can reach more than 98% within 10 minutes.

[0090] like Figure 11 It is known that Ni-MOF materials can also activate PMS to accelerate the degradation of various organic pollutants. Compared with Ni-MOF alone ( Figure 11 (a) In this context, after adding PMS, Ni-MOF can remove 100% of various organic pollutants within 100 minutes. Figure 11 (b)

[0091] The Zn-MOF, Mn-MOF, and Co-MOF materials prepared in Examples 3 and 4 can also activate PMS to accelerate the degradation of various organic pollutants, and can remove 100% of various organic pollutants within 100 minutes.

[0092] Recyclability testing of materials after tetracycline removal:

[0093] The Fe-MOF or Ni-MOF material after tetracycline removal was soaked in ethanol for 30 minutes and then dried to obtain dried Fe-MOF or Ni-MOF material. The above tetracycline removal process was repeated for a total of 5 cycles. The removal rate of tetracycline by Fe-MOF material is shown in Table 2.

[0094]

[0095] As shown in Table 2, the Fe-MOF and Ni-MOF materials still have good removal rates for various organic pollutants after five cycles of PMS or H2O2 activation, thus the Fe-MOF and Ni-MOF materials have good recyclability.

[0096] Example 6

[0097] This study investigated the activation of H₂O₂ or PMS by Fe-MOF or Ni-MOF in actual water bodies to catalyze the degradation of organic pollutants. 5 mg of Fe-MOF or Ni-MOF material was added to an aqueous solution of Dianchi Lake in Kunming, Yunnan Province, containing TC (3 mg / L), RhB (3 mg / L), EE₂ (3 mg / L), and bisphenol A (BPA) (3 mg / L). The reaction was shaken for 3 minutes, and samples were taken at predetermined time intervals and filtered using a 0.45 μm filter. The adsorbed filtrate was collected in centrifuge tubes, and the concentration of the corresponding pollutants was determined by liquid chromatography.

[0098] according to Figure 12 It can be seen that Fe-MOF can achieve a degradation rate of over 99% for TC and RhB and over 70% for EE2 and BPA under the catalysis of H2O2 or PMS.

[0099] Ni-MOF can achieve a degradation rate of over 90% for TC, RhB, EE2, and BPA under the catalysis of H2O2 or PMS.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A pyrazole organic monomer, characterized in that, Its structural formula is 。 2. The method for preparing the pyrazole organic monomer as described in claim 1, characterized in that, Includes the following steps: (1) First, 1,3,6,8-tetrabromopyrene, 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester, tetrabutylammonium bromide and tetra(triphenylphosphine)palladium are added to alkaline organic solvent A and stirred or sonicated under an inert gas atmosphere. (2) After heating and refluxing in an inert gas atmosphere and cooling to room temperature, the mixture is subjected to rotary evaporation, extraction, and rotary evaporation. Then, alcohol and acid A are added and sonicated. Finally, the mixture is stirred until the acidification reaction is complete to obtain a suspension. (3) After adjusting the pH to 7 by pouring the suspension into water, the precipitate was obtained, washed, and dried to obtain the pyrazole organic monomer.

3. The method for preparing the pyrazole organic monomer as described in claim 2, characterized in that, The molar ratio of 1,3,6,8-tetrabromopyrene and 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester is 1:(4-8); the molar ratio of 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester to tetrabutylammonium bromide is (15-30):1; the molar ratio of 1-(2-tetrahydropyranyl)pyrazole-5-boronic acid pinacol ester to tetra(triphenylphosphine)palladium is (60-120):1; the base in the alkaline organic solvent A is an aqueous solution of potassium carbonate, and organic solvent A is toluene or xylene.

4. The method for preparing the pyrazole organic monomer as described in claim 2, characterized in that, In step (2), the alcohol is methanol or ethanol, and acid A is nitric acid, hydrochloric acid or sulfuric acid; the acidification reaction time is 4-8 h; the extraction liquid used in the extraction is a mixture of solvent and water, the solvent is dichloromethane or dichloroethane, and the volume ratio of solvent to water is 1:(0.5-1); the reflux temperature is 100-135℃, the time is 24-72 h, and the heating method is oil bath or sand bath.

5. The method for preparing the pyrazole organic monomer as described in claim 2, characterized in that, In step (3), the volume ratio of the suspension to water is 1:(5-10).

6. A three-dimensional MOF material, characterized in that, Ni-MOF or Fe-MOF metal-organic framework materials are prepared by a solvothermal method using the pyrazole organic monomer described in claim 1 as a ligand and nickel or iron salt as a metal salt. When the metal salt is a nickel salt, the solvothermal method includes the following steps: dissolving the pyrazole organic monomer in organic solvent B, then adding methanol, dimethyl sulfoxide, acid B, and nickel salt solution, and sonicating to obtain Ni-MOF; wherein the organic solvent B is dimethyl sulfoxide, N,N-dimethylformamide, or N,N-dimethylacetamide; When the metal salt is an iron salt, the solvothermal method includes the following steps: dissolving the pyrazole organic monomer in N,N-dimethylformamide, then adding acetonitrile, dimethyl sulfoxide, acid B and iron salt solution, sonicating, and heating to react and obtain Fe-MOF.

7. The three-dimensional MOF material as described in claim 6, characterized in that, When the metal salt is a nickel salt, the concentration of the pyrazole organic monomer in the organic solvent B is 5-20 mg / mL, the acid B is glacial acetic acid, the volume ratio of methanol, dimethyl sulfoxide, acid B and nickel salt solution is 10:(5-10):(0.7-1):(0.1-0.2), and the concentration of nickel salt solution is 0.02 g / mL; When the metal salt is an iron salt, the volume ratio of acetonitrile, dimethyl sulfoxide, acid B and iron salt solution is 10:(2-5):(0.7-1):(0.1-0.2), acid B is glacial acetic acid, and the concentration of iron salt solution is 0.02 g / mL; The heating reaction is carried out at a temperature of 100-140℃ for 12-56 hours, with a heating rate of 10-20℃ / hour.

8. The application of the three-dimensional MOF material as described in claim 6 in the removal of heavy metal ions and / or organic pollutants from water, wherein the three-dimensional MOF material is Ni-MOF, the heavy metal ions are Pb or Hg, and the organic pollutants are tetracycline, 17α-ethynylestradiol, rhodamine B, and methylene blue.

9. The application of the three-dimensional MOF material as described in claim 6 in activating PMS or H2O2 to remove organic pollutants from water, wherein the organic pollutants in the water are tetracycline, bisphenol A, 17α-ethynylestradiol, and rhodamine B.

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