A kind of Zn-MOF material and its preparation method and application in congo red dye adsorption
By preparing Zn-MOF materials, the problem of Congo red dye wastewater treatment was solved, achieving a high-efficiency adsorption effect with an adsorption capacity of 13226 mg g-1, thus improving the water pollution problem.
Patent Information
- Application Number
- CN202411982133.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2044-12-31
AI Technical Summary
Existing technologies are insufficient for effectively treating Congo red dye wastewater, especially due to its chemical stability and high toxicity, which makes it difficult for microorganisms to degrade it.
Zn-MOF materials were prepared by mixing 3,6-bis(2-methylimidazolium)pyridazine with isophthalic acid and zinc source in an alkaline solvent environment to form a Zn-MOF material with a two-dimensional tetragonal lattice structure, which was used to adsorb Congo red dye.
It achieved highly efficient adsorption of Congo red dye, with an adsorption capacity of 13226 mg g⁻¹, which significantly improved the water pollution treatment effect.
Smart Images
Figure CN119613758B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of metal organic framework materials, and particularly relates to a Zn-MOF material, a preparation method thereof and application of the Zn-MOF material in Congo red dye adsorption. BACKGROUND
[0002] In recent years, water pollution and its management problem have been concerned. It is worrying that toxins in wastewater, such as dyes, heavy metals, antibacterial agents and the like, even at very low concentrations, can have a devastating impact on aquatic organisms and humans, and even cause cancer. The pollution of water resources is mainly caused by organic and inorganic waste generated in industrial and agricultural production and life. Due to the development of the textile industry, the amount of dye wastewater discharged is increasing year by year, and about 10-15% of the dyes are discharged from printing production. Congo red (CR) is a classic anionic azo dye, which is often used in the manufacture of textiles, rubber and plastics. It has high toxicity, carcinogenicity and antioxidant properties, and poses a real risk to the ecosystem and biological health. In addition, the aromatic structure of azo dyes makes them chemically stable and difficult to be degraded by microorganisms, which makes the treatment of CR dye wastewater more difficult. Therefore, it is urgent to provide a solution to improve the above problems. SUMMARY
[0003] The present application aims to provide a Zn-MOF material, a preparation method thereof and application of the Zn-MOF material in Congo red dye adsorption.
[0004] In a first aspect, the present application provides a preparation method of a Zn-MOF material, comprising: reacting 2-methyl imidazole and 3,6-dichloropyridazine to generate 3,6-bis(2-methyl imidazole) pyridazine in an alkaline solvent environment; and preparing the Zn-MOF material by mixing and coordinating 3,6-bis(2-methyl imidazole) pyridazine, isophthalic acid and a zinc source.
[0005] Optionally, the alkaline solute in the alkaline solvent environment comprises one of sodium hydroxide, potassium hydroxide and sodium bicarbonate.
[0006] Optionally, the solvent environment comprises one of dimethyl sulfoxide, N,N-dimethylacetamide and N,N-dimethylformamide.
[0007] Optionally, the pH in the solvent environment is 8-11.
[0008] Optionally, one of the 2-methyl imidazole and the 3,6-dichloropyridazine is provided in excess.
[0009] Optionally, the molar ratio of the 2-methyl imidazole to the 3,6-dichloropyridazine is 1:(2-3).
[0010] Optionally, 2-methylimidazole is reacted with 3,6-dichloropyridazine at 50-70 °C for 3-5 h.
[0011] Optionally, a basic solute, 2-methylimidazole, is added to a solvent environment, and after refluxing at 50-70 °C for 0.1-1 h, 3,6-dichloropyridazine is added and stirred to react. After cooling, the product is separated by suction filtration and dried to obtain 3,6-bis(2-methylimidazole)pyridazine.
[0012] Optionally, 3,6-bis(2-methylimidazole)pyridazine and isophthalic acid are mixed and dissolved in a polar solvent, and a zinc source is added to perform a coordination reaction to obtain a Zn-MOF material; preferably, the 3,6-bis(2-methylimidazole)pyridazine, the isophthalic acid, and the zinc source are mixed and dissolved in a mixture of a polar solvent and deionized water.
[0013] Optionally, the molar ratio of the 3,6-bis(2-methylimidazole)pyridazine to the isophthalic acid is 1:(1-2).
[0014] Optionally, the molar ratio of the 3,6-bis(2-methylimidazole)pyridazine to zinc ions in the zinc source is 1:(2-3).
[0015] Optionally, the polar solvent includes N,N-dimethylacetamide or N,N-dimethylformamide.
[0016] Optionally, the zinc source includes one of zinc nitrate and a hydrate thereof.
[0017] Optionally, the volume ratio of the polar solvent to the deionized water is (1-6):1.
[0018] Optionally, after mixing the 3,6-bis(2-methylimidazole)pyridazine, the isophthalic acid, and the zinc source, the mixture is reacted at 80-90 °C for 20-28 h.
[0019] Optionally, after the coordination reaction, the mixture is washed and dried to obtain the Zn-MOF material.
[0020] In a second aspect, the present application also provides a Zn-MOF material prepared by any of the optional preparation methods described above.
[0021] In a third aspect, the present application also provides a use of a Zn-MOF material prepared by any of the optional preparation methods described above in Congo red dye adsorption. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 A flowchart of a preparation method of a Zn-MOF material according to the present application is shown in FIG. 1.
[0023] Figure 2 A nuclear magnetic resonance hydrogen spectrum of 3,6-bis(2-methylimidazole)pyridazine prepared according to the present application is shown in FIG. 2.
[0024] Figure 3 NMR carbon spectrum of 3,6-bis(2-methylimidazole) pyridazine prepared in the application;
[0025] Figure 4 Schematic diagram of the three-dimensional structure of the monomer of the Zn-MOF material prepared in the application;
[0026] Figure 5 Schematic diagram of the three-dimensional structure of the Zn-MOF material prepared in the application;
[0027] Figure 6 Isothermal adsorption curve of the Zn-MOF material prepared in Example 2 of the application on Congo red solution;
[0028] Figure 7 Comparison chart of Congo red solution before and after adsorption of the Zn-MOF material prepared in Example 1 of the application on 100 ppm Congo red solution;
[0029] Figure 8 Comparison chart of Congo red solution before and after adsorption of the Zn-MOF material prepared in Example 2 of the application on 1000 ppm Congo red solution;
[0030] Figure 9 Comparison chart of Congo red solution before and after adsorption of the Zn-MOF material prepared in Example 3 of the application on 100 ppm Congo red solution;
[0031] Figure 10 Comparison chart of Congo red solution before and after adsorption of the Zn-MOF material prepared in Example 4 of the application on 1000 ppm Congo red solution. DETAILED DESCRIPTION
[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme of the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are some embodiments of the application, but not all the embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application. Unless otherwise defined, the technical terms or scientific terms used herein should have the usual meanings understood by those skilled in the art.
[0033] Reference Figure 1 The application provides a preparation method of a Zn-MOF material, comprising the following steps:
[0034] S1, 2-methylimidazole reacts with 3,6-dichloropyridazine to generate 3,6-bis(2-methylimidazole) pyridazine in an alkaline solvent environment;
[0035] S2, the Zn-MOF material is prepared by mixing and coordinating 3,6-bis(2-methylimidazole) pyridazine, isophthalic acid and a zinc source.
[0036] In some embodiments, the basic solute in the basic solvent environment used includes one of sodium hydroxide, potassium hydroxide and sodium bicarbonate, and the solvent environment used includes one of dimethyl sulfoxide, N,N-dimethylacetamide and N,N-dimethylformamide. Specifically, in the preparation of 3,6-bis(2-methylimidazole) pyridazine in step S1, the basic environment can promote the reaction to proceed in the forward direction, and the solvent environment can make 2-methylimidazole and 3,6-dichloropyridazine uniformly distributed. In fact, the pH in the basic solvent environment is 8-11.
[0037] In some embodiments, in step S1, one of 2-methylimidazole and 3,6-dichloropyridazine is set in excess, which is conducive to promoting the reaction to proceed in the forward direction, thereby improving the yield of 3,6-bis(2-methylimidazole) pyridazine. Specifically, the molar ratio of 2-methylimidazole to 3,6-dichloropyridazine in the reaction is 1:(2-3). In addition, to further promote the reaction, 2-methylimidazole and 3,6-dichloropyridazine can be reacted at 50-70°C for 3-5h.
[0038] In some embodiments, in step S1, the basic solute and 2-methylimidazole are added to the solvent environment, and after refluxing at 50-70°C for 0.1-1h, 3,6-dichloropyridazine is added for stirring reaction. After cooling, 3,6-bis(2-methylimidazole) pyridazine is separated and dried by filtration. Specifically, when the basic solute and 2-methylimidazole are added to the solvent environment, the molar ratio of the basic solute to 2-methylimidazole is 1:1.
[0039] In some embodiments, after adding 3,6-dichloropyridazine for stirring reaction and cooling, the reaction system is added to an ice water mixture and stored in a refrigerator. Then, 3,6-bis(2-methylimidazole) pyridazine is precipitated, and after separating the solid phase by solid-liquid separation means, the mother liquor is used for washing and drying, thereby preparing 3,6-bis(2-methylimidazole) pyridazine. Specifically, when the reaction system is added to the ice water mixture, the volume ratio of the reaction system to the ice water mixture is 1:(10-15).
[0040] In fact, the reaction formula for generating 3,6-bis(2-methylimidazole) pyridazine from 2-methylimidazole and 3,6-dichloropyridazine in step S1 is as follows:
[0041]
[0042] In addition, after the 3,6-bis(2-methylimidazole) pyridazine prepared in step S1 is subjected to nuclear magnetic characterization, its hydrogen spectrum and carbon spectrum are as shown in Figure 2 and Figure 3 respectively.
[0043] In some embodiments, when step S2 is performed, the 3,6-bis(2-methylimidazole) pyridazine, isophthalic acid and zinc source are mixed and dissolved in a polar solvent to prepare the Zn-MOF material by coordination reaction. In fact, by reacting in a polar solvent, the three reactants can be dissolved and mixed. Specifically, the polar solvent used includes N,N-dimethylacetamide or N,N-dimethylformamide.
[0044] In some further embodiments, when step S2 is performed, the 3,6-bis(2-methylimidazole) pyridazine, isophthalic acid and zinc source are mixed and dissolved in a mixture of polar solvent and deionized water. Specifically, the volume ratio of polar solvent to deionized water in the mixture is (1-6):1. In addition, the molar ratio of 3,6-bis(2-methylimidazole) pyridazine, isophthalic acid and zinc ion in the zinc source is 1:(1-2):(2-3).
[0045] In some embodiments, the zinc source used includes one of zinc nitrate and its hydrate. Specifically, the zinc source used is necessary to be completely dissolved in the polar solvent. In addition, when preparing the Zn-MOF material, after the 3,6-bis(2-methylimidazole) pyridazine, isophthalic acid and zinc source are mixed, the reaction is carried out at 80-90°C for 20-28h, and after the coordination reaction, washing and drying are carried out, thereby preparing the Zn-MOF material.
[0046] In fact, the present application also provides a Zn-MOF material prepared by the preparation method of any one of the optional embodiments described above. Referring to Figure 4 , the monomer of the Zn-MOF material is composed of 40 carbon atoms, 32 hydrogen atoms, 12 nitrogen atoms, 2 zinc atoms and 8 oxygen atoms, and the relative molecular mass of the monomer is 939.51g / mol; the asymmetric unit is composed of 1 Zn(II) ion, 1 3,6-bis(2-methylimidazole) pyridazine ligand, 1 deprotonated isophthalic acid ligand and two uncoordinated water molecules, and each 3,6-bis(2-methylimidazole) pyridazine ligand is connected with two Zn(II) ions, thereby forming a stack of Z-shaped chains and constructing a two-dimensional square lattice monolayer structure as shown in Figure 5 .
[0047] Embodiment 1
[0048] The present embodiment 1 provides a preparation method of a Zn-MOF material, comprising the following steps:
[0049] S1, 0.1402 g of sodium hydroxide and 0.2759 g of 2-methylimidazole were mixed and dissolved in 10 mL of dimethyl sulfoxide, after condensation refluxing at 60°C for 0.5 h, 0.2 g of 3,6-dichloropyridazine (CAS: 141-30-0) was added and stirred at 60°C for 4 h, after natural cooling to room temperature, it was poured into 150 mL of ice water mixture, refrigerated for 24 h, then filtered, washed with deionized water three times, and dried in a 70°C oven to constant weight to obtain 3,6-bis(2-methylimidazole) pyridazine;
[0050] S2, 3.127 g of zinc nitrate hexahydrate, 1.272 g of 3,6-bis(2-methylimidazole) pyridazine, and 0.8798 g of isophthalic acid were dissolved in 10.5 mL of N,N-dimethylformamide, respectively, 2 mL of N,N-dimethylformamide and 1 mL of deionized water were added to each scintillation vial, 0.2 mL of N,N-dimethylformamide solution of zinc nitrate hexahydrate, 0.2 mL of N,N-dimethylformamide solution of 3,6-bis(2-methylimidazole) pyridazine, and 0.2 mL of N,N-dimethylformamide solution of isophthalic acid were added to each scintillation vial in turn, sealed and reacted in an 85°C oven for 24 h, then filtered and separated after natural cooling to room temperature, washed with a mixture of N,N-dimethylformamide and deionized water three times, soaked in acetonitrile at room temperature for 48 h, and vacuum dried to obtain a Zn-MOF material (NCD-123).
[0051] Example 2
[0052] The present example 2 provides a preparation method of a Zn-MOF material, comprising the following steps:
[0053] S1, 0.1402 g of sodium hydroxide and 0.2759 g of 2-methylimidazole were mixed and dissolved in 10 mL of dimethyl sulfoxide, after condensation refluxing at 60°C for 0.5 h, 0.2 g of 3,6-dichloropyridazine (CAS: 141-30-0) was added and stirred at 60°C for 4 h, after natural cooling to room temperature, it was poured into 150 mL of ice water mixture, refrigerated for 24 h, then filtered, washed with deionized water three times, and dried in a 70°C oven to constant weight to obtain 3,6-bis(2-methylimidazole) pyridazine;
[0054] S2, 6.195 g of zinc nitrate hexahydrate, 2.52 g of 3,6-bis(2-methylimidazol) pyridazine, 1.743 g of isophthalic acid were dissolved in 21 mL of N,N-dimethylformamide, respectively, 2 mL of N,N-dimethylformamide and 1 mL of deionized water were loaded into 100 scintillation vials, respectively, then 0.2 mL of N,N-dimethylformamide solution of zinc nitrate hexahydrate, 0.2 mL of N,N-dimethylformamide solution of 3,6-bis(2-methylimidazol) pyridazine, 0.2 mL of N,N-dimethylformamide solution of isophthalic acid were added into each scintillation vial in turn, sealed and reacted in an 85°C oven for 24 h, then naturally cooled to room temperature, separated by suction filtration, washed with a mixture of N,N-dimethylformamide and deionized water for three times, then soaked in acetonitrile at room temperature for 48 h, and vacuum dried to obtain the Zn-MOF material (NCD-123).
[0055] Example 3
[0056] This example 3 provides a preparation method of a Zn-MOF material, which is different from example 2 in that 6 mL of N,N-dimethylformamide and 1 mL of deionized water are loaded into 100 scintillation vials in step S2, respectively.
[0057] Example 4
[0058] This example 4 provides a preparation method of a Zn-MOF material, which is different from example 1 in that 1 mL of N,N-dimethylformamide and 2 mL of deionized water are loaded into 50 scintillation vials in step S2, respectively.
[0059] Performance detection
[0060] The Zn-MOF material (NCD-123) prepared in example 2 was tested for adsorption capacity under different concentrations of CR solution, and the isothermal adsorption curve is shown in Figure 6 From Figure 6 it can be seen that as the concentration of CR solution increases, the adsorption capacity of the adsorbent also increases. According to the fitting results, the adsorption capacity of NCD-123 for CR at room temperature (298 K) is 13226 mg g -1 .
[0061] 20 mg of Zn-MOF material (NCD-123) prepared in example 1 and example 3 was added into 100 mL of 100 ppm concentration of Congo red solution, respectively, and reacted for 4 h under magnetic stirring at 500 rpm, then separated, and the results are shown in Figure 7 and Figure 9The results are shown in Table 1 below. Figure 8 and Figure 10 The results are shown in Table 1 below.
[0062] Table 1 Concentration values of Congo red solution before and after adsorption
[0063] Before adsorption / ppm After adsorption / ppm Example 1 100 1.2 Example 2 1000 145 Example 3 100 0.7 Example 4 1000 116
[0064] The Zn-MOF material in Example 2 was subjected to crystal type characterization, and the crystal type result data is shown in Table 2 below:
[0065] Table 2 Crystal type structure data of Zn-MOF material prepared in Example 2
[0066]
[0067]
[0068] While the embodiments of the present application have been described in detail, it is apparent to those skilled in the art that various modifications and changes can be made to the embodiments without departing from the scope and spirit of the present application as recited in the claims. Moreover, the present application described herein can have other embodiments and be practiced or implemented in various ways.
Claims
1. A method for preparing Zn-MOF materials, characterized in that, include: In an alkaline solvent environment, 2-methylimidazolium reacts with 3,6-dichloropyridazine to generate 3,6-bis(2-methylimidazolium)pyridazine; Zn-MOF materials are prepared by mixing and coordinating 3,6-bis(2-methylimidazolium)pyridazine, isophthalic acid and zinc source.
2. The preparation method according to claim 1, characterized in that: The alkaline solute in the alkaline solvent environment includes one of sodium hydroxide, potassium hydroxide, and sodium bicarbonate; and / or, the solvent environment includes dimethyl sulfoxide, N , N -Dimethylacetamide, N , N One of dimethylformamides; and / or, the pH of the solvent environment is 9-11.
3. The preparation method according to claim 1, characterized in that: An excess of either 2-methylimidazole or 3,6-dichloropyridazine.
4. The preparation method according to claim 3, characterized in that: The molar ratio of 2-methylimidazole to 3,6-dichloropyridazine is 1:(2-3).
5. The preparation method according to claim 1, characterized in that: 2-Methylimidazole was reacted with 3,6-dichloropyridazine at 50℃-70℃ for 3-5 hours.
6. The preparation method according to any one of claims 1 to 5, characterized in that, An alkaline solute and 2-methylimidazole were added to a solvent environment and refluxed at 50℃-70℃ for 0.1h-1h. Then, 3,6-dichloropyridazine was added and stirred to react. After cooling, the mixture was filtered, separated, and dried to obtain 3,6-bis(2-methylimidazole)pyridazine.
7. The preparation method according to claim 1, characterized in that, Zn-MOF materials were prepared by mixing and dissolving 3,6-bis(2-methylimidazolium)pyridazine, isophthalic acid, and zinc source in a polar solvent or a mixture of polar solvent and deionized water, followed by a coordination reaction.
8. The preparation method according to claim 7, characterized in that: The molar ratio of the 3,6-bis(2-methylimidazolium)pyridazine to the isophthalic acid is 1:(1-2); and / or, the molar ratio of the 3,6-bis(2-methylimidazolium)pyridazine to zinc ions in the zinc source is 1:(2-3); and / or, the polar solvent includes N , N -Dimethylacetamide or N , N -Dimethylformamide; and / or, the zinc source includes one of zinc nitrate and its hydrate.
9. The preparation method according to claim 7, characterized in that: The volume ratio of the polar solvent to the deionized water is (1-6):1; and / or, 3,6-bis(2-methylimidazolium)pyridazine, isophthalic acid and zinc source are mixed and reacted at 80℃-90℃ for 20h-28h; and / or, after mixing and coordination, the mixture is washed and dried to obtain Zn-MOF material.
10. A Zn-MOF material prepared by the preparation method according to any one of claims 1 to 9.
11. The application of a Zn-MOF material prepared by any one of claims 1 to 9 in the adsorption of Congo red dye.
Citation Information
Patent Citations
Preparation and application of nickel-nickel nitride nanocomposite based on double-ligand MOF precursor
CN112808293A
Metal organic framework drug-loaded nano system based on small molecule drug
CN112891548A