Modified metal organic framework material and preparation method thereof

Abstract

The invention discloses a modified metal organic framework material and a preparation method thereof, and belongs to the technical field of metal organic framework materials.The preparation method comprises the steps that zirconium nitrate pentahydrate is dissolved in water to prepare a zirconium nitrate solution, ceric ammonium nitrate is dissolved in water to prepare a ceric ammonium nitrate solution, and the ceric ammonium nitrate solution is dissolved in water to prepare the modified metal organic framework material; uniformly mixing the zirconium nitrate solution and the ammonium ceric nitrate solution in proportion to obtain a metal solution; the preparation method comprises the following steps: adding 1, 4-terephthalic acid serving as an organic ligand into DMF (Dimethyl Formamide), and uniformly mixing to obtain a ligand solution; the preparation method comprises the following steps: adding benzoic acid into a metal solution, stirring for 0.7-1h at 200-250r / min in a microwave-assisted manner, adding a ligand solution, carrying out a synthetic reaction for 10-13min at 95-98 DEG C, and washing and drying to obtain the modified metal organic framework material. The modified metal organic framework material prepared by the invention improves the degradation capacity of tetracycline in wastewater, and effectively shortens the synthesis time. When the dosage is 0.5 g / L, the appropriate concentration of tetracycline (TC) in the degraded wastewater is 19-22 ppm, and the TC degradation rate is higher than 92%.

Description

Technical Field

[0001] The present invention relates to the technical field of metal organic framework material preparation, and in particular to a modified metal organic framework material and a preparation method thereof. Background Art

[0002] Metal-organic frameworks (MOFs) are porous materials composed of metal ion clusters linked by multi-site organic ligands through coordination bonds. They possess high surface area, tunable pore structure, and excellent chemical stability. They are widely used in catalysis, sensing, separation, gas storage, and other fields.

[0003] UiO-66 is a highly porous metal-organic framework (MOF) material characterized by a structure consisting of an octahedral central cage and eight tetrahedral corner cages. UiO-66 exhibits extremely high chemical, thermal, and mechanical stability.

[0004] Due to the limited Lewis acid sites inherent in UiO-66, its degradation performance is limited. Therefore, it is necessary to enhance degradation performance through ligand design, defect engineering, or metal modification. However, most current synthetic methods for modified UiO-66 suffer from drawbacks such as long synthesis times, and the degradation performance of tetracycline in water still needs to be further improved.

[0005] Based on this, the present invention designs a modified metal organic framework material and a preparation method thereof to solve the above problems. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a modified metal organic framework material and a preparation method thereof.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for preparing a modified metal-organic framework material comprises the following steps: dissolving zirconium nitrate pentahydrate in water to prepare a zirconium nitrate solution, dissolving ceric ammonium nitrate in water to prepare an ammonium ceric nitrate solution, and uniformly mixing the zirconium nitrate solution and the ammonium ceric nitrate solution in proportion to obtain a metal solution; using 1,4-terephthalic acid as an organic ligand, adding the mixture to DMF and mixing the mixture uniformly to obtain a ligand solution; starting stirring, adding benzoic acid to the metal solution, stirring at 200-250 r / min for 0.7-1 hour in a microwave-assisted manner, then adding the ligand solution, carrying out a synthesis reaction at 95-98°C for 10-13 minutes, and washing and drying to obtain the modified metal-organic framework material.

[0008] Furthermore, Zr in the metal solution 4+ 、Ce 4+ The molar ratio of 1,4-terephthalic acid to the ligand solution is 3~4:1:5~6.

[0009] Furthermore, Zr in the metal solution 4+ 、Ce 4+ The molar ratio of benzoic acid to benzoic acid is 3~4:1:1.2~2.

[0010] Furthermore, zirconium nitrate pentahydrate is dissolved in water to prepare a 1.2-1.5 mol / L zirconium nitrate solution; and cerium ammonium nitrate is dissolved in water to prepare a 0.3-0.5 mol / L cerium ammonium nitrate solution.

[0011] Furthermore, zirconium nitrate solution and cerium ammonium nitrate solution are mixed in an ion ratio of Zr 4+ :Ce 4+ =3~4:1 and mix evenly to obtain a metal solution.

[0012] Furthermore, the microwave power is 220~250W.

[0013] In order to better achieve the purpose of the present invention, the present invention also provides a modified metal organic framework material prepared according to the preparation method.

[0014] In order to better achieve the purpose of the present invention, the present invention also provides the use of the modified metal organic framework material in the degradation of tetracycline in water.

[0015] Compared to existing technologies, the modified metal-organic framework (MOF) material prepared by this invention has the following advantages: it improves the degradation capacity of tetracycline in wastewater and effectively reduces the synthesis time. The modified MOF material can degrade tetracycline (TC) in wastewater at an optimum concentration of 19-22 ppm, with a dosage of 0.5 g / L, achieving a TC degradation rate exceeding 92%. DETAILED DESCRIPTION

[0016] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] Example 1: A method for preparing a modified metal organic framework material, comprising the following steps: dissolving zirconium nitrate pentahydrate in water to prepare a 1.2 mol / L zirconium nitrate solution, dissolving ceric ammonium nitrate in water to prepare a 0.3 mol / L ceric ammonium nitrate solution, and uniformly mixing the zirconium nitrate solution and the ceric ammonium nitrate solution to obtain a metal solution; using 1,4-terephthalic acid as an organic ligand, adding it to DMF (adding 2.5 mL DMF per mmol of ligand), mixing uniformly, and obtaining a ligand solution; starting stirring, taking the metal solution, and adding benzoic acid (Ce 4+ : benzoic acid molar ratio = 1:2), microwave-assisted method (microwave power 220W), stirring at 250r / min for 0.7h, then adding ligand solution (Ce 4+ : 1,4-terephthalic acid molar ratio = 1:6), the synthesis reaction is carried out at 98°C for 10 minutes, and the modified metal organic framework material is obtained after washing and drying.

[0018] Test results: The concentration of tetracycline (TC) in the wastewater was 16 ppm, the dosage of the modified metal organic framework material was 0.5 g / L, and the TC degradation rate was detected: 94.6%.

[0019] Example 2: A method for preparing a modified metal organic framework material, comprising the following steps: dissolving zirconium nitrate pentahydrate in water to prepare a 1.5 mol / L zirconium nitrate solution, dissolving ceric ammonium nitrate in water to prepare a 0.5 mol / L ceric ammonium nitrate solution, and uniformly mixing the zirconium nitrate solution and the ceric ammonium nitrate solution to obtain a metal solution; using 1,4-terephthalic acid as an organic ligand, adding 3 mL of DMF per mmol of ligand, and mixing uniformly to obtain a ligand solution; starting stirring, taking the metal solution, and adding benzoic acid (Ce 4+ : benzoic acid molar ratio = 1:1.2), microwave-assisted method (microwave power 250W), stirring at 200r / min for 1h, then adding ligand solution (Ce 4+ : 1,4-terephthalic acid molar ratio = 1:5), the synthesis reaction is carried out at 95°C for 13 minutes, and the modified metal organic framework material is obtained after washing and drying.

[0020] Test results: The concentration of tetracycline (TC) in the wastewater was 18 ppm, the dosage of the modified metal organic framework material was 0.5 g / L, and the TC degradation rate was detected: 94.1%.

[0021] Example 3: A method for preparing a modified metal organic framework material, comprising the following steps: dissolving zirconium nitrate pentahydrate in water to prepare a 1.3 mol / L zirconium nitrate solution, dissolving ceric ammonium nitrate in water to prepare a 0.45 mol / L ceric ammonium nitrate solution, and uniformly mixing the zirconium nitrate solution and the ceric ammonium nitrate solution to obtain a metal solution; using 1,4-terephthalic acid as an organic ligand, adding it to DMF (adding 2.8 mL DMF per mmol of ligand), mixing uniformly, and obtaining a ligand solution; starting stirring, taking the metal solution, and adding benzoic acid (Ce 4+ : benzoic acid molar ratio = 1:1.3), microwave-assisted method (microwave power 240W), stirring at 210r / min for 0.8h, then adding ligand solution (Ce 4+ : 1,4-terephthalic acid molar ratio = 1:5.5), the synthesis reaction is carried out at 95°C for 11 minutes, and the modified metal organic framework material is obtained after washing and drying.

[0022] Test results: The concentration of tetracycline (TC) in the wastewater was 19 ppm, the dosage of the modified metal organic framework material was 0.5 g / L, and the TC degradation rate was detected: 93.7%.

[0023] Example 4: A method for preparing a modified metal organic framework material, comprising the following steps: dissolving zirconium nitrate pentahydrate in water to prepare a 1.4 mol / L zirconium nitrate solution, dissolving ceric ammonium nitrate in water to prepare a 0.35 mol / L ceric ammonium nitrate solution, and uniformly mixing the zirconium nitrate solution and the ceric ammonium nitrate solution to obtain a metal solution; using 1,4-terephthalic acid as an organic ligand, adding it to DMF (adding 2.8 mL DMF per mmol of ligand), mixing uniformly, and obtaining a ligand solution; starting stirring, taking the metal solution, and adding benzoic acid (Ce 4+ : benzoic acid molar ratio = 1:1.4), microwave-assisted method (microwave power 235W), stirring at 220r / min for 0.8h, then adding ligand solution (Ce 4+ : 1,4-terephthalic acid molar ratio = 1:5.2), the synthesis reaction was carried out at 97°C for 10.5min, and the modified metal organic framework material was obtained after washing and drying.

[0024] Test results: The concentration of tetracycline (TC) in the wastewater was 20 ppm, the dosage of the modified metal-organic framework material was 0.5 g / L, and the TC degradation rate was detected: 93.6%.

[0025] Example 5: A method for preparing a modified metal organic framework material, comprising the following steps: dissolving zirconium nitrate pentahydrate in water to prepare a 1.3 mol / L zirconium nitrate solution, dissolving ceric ammonium nitrate in water to prepare a 0.4 mol / L ceric ammonium nitrate solution, and uniformly mixing the zirconium nitrate solution and the ceric ammonium nitrate solution to obtain a metal solution; using 1,4-terephthalic acid as an organic ligand, adding it to DMF (adding 2.8 mL DMF per mmol of ligand), mixing uniformly, and obtaining a ligand solution; starting stirring, taking the metal solution, and adding benzoic acid (Ce 4+ : benzoic acid molar ratio = 1:1.6), microwave assisted method (microwave power 230W), stirring at 230r / min for 0.8h, then adding ligand solution (Ce 4+ : 1,4-terephthalic acid molar ratio = 1:5.6), the synthesis reaction was carried out at 96°C for 11.5min, and the modified metal organic framework material was obtained after washing and drying.

[0026] Test results: The concentration of tetracycline (TC) in the wastewater was 21ppm, the dosage of the modified metal organic framework material was 0.5g / L, and the TC degradation rate was detected: 93.3%.

[0027] Example 6: A method for preparing a modified metal organic framework material, comprising the following steps: dissolving zirconium nitrate pentahydrate in water to prepare a 1.4 mol / L zirconium nitrate solution, dissolving ceric ammonium nitrate in water to prepare a 0.3 mol / L ceric ammonium nitrate solution, and uniformly mixing the zirconium nitrate solution and the ceric ammonium nitrate solution to obtain a metal solution; using 1,4-terephthalic acid as an organic ligand, adding it to DMF (adding 2.8 mL DMF per mmol of ligand), mixing uniformly, and obtaining a ligand solution; starting stirring, taking the metal solution, and adding benzoic acid (Ce 4+ : benzoic acid molar ratio = 1:1.5), microwave-assisted method (microwave power 225W), stirring at 245r / min for 0.9h, then adding ligand solution (Ce 4+ : 1,4-terephthalic acid molar ratio = 1:5.5), the synthesis reaction is carried out at 95.5°C for 12 minutes, and the modified metal organic framework material is obtained after washing and drying.

[0028] Test results: The concentration of tetracycline (TC) in the wastewater was 22 ppm, the dosage of the modified metal organic framework material was 0.5 g / L, and the TC degradation rate was detected: 92.7%.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing a modified metal organic framework material, characterized in that: The method comprises the following steps: dissolving zirconium nitrate pentahydrate in water to prepare a zirconium nitrate solution, dissolving ceric ammonium nitrate in water to prepare an ammonium ceric nitrate solution, and uniformly mixing the zirconium nitrate solution and the ammonium ceric nitrate solution in proportion to obtain a metal solution; using 1,4-terephthalic acid as an organic ligand, adding the mixture into DMF and mixing the mixture uniformly to obtain a ligand solution; starting stirring, adding benzoic acid to the metal solution, stirring at 200-250 r / min for 0.7-1 hour in a microwave-assisted manner, then adding the ligand solution, carrying out a synthesis reaction at 95-98°C for 10-13 minutes, and obtaining a modified metal-organic framework material after washing and drying.

2. The method for preparing a modified metal organic framework material according to claim 1, characterized in that: Zr in metal solution 4+ 、Ce 4+ The molar ratio of 1,4-terephthalic acid to the ligand solution is 3~4:1:5~6.

3. The method for preparing a modified metal organic framework material according to claim 1, characterized in that: Zr in metal solution 4+ 、Ce 4+ The molar ratio of benzoic acid to benzoic acid is 3~4:1:1.2~2.

4. The method for preparing a modified metal organic framework material according to claim 1, wherein: Dissolve zirconium nitrate pentahydrate in water to prepare a 1.2-1.5 mol / L zirconium nitrate solution; dissolve ceric ammonium nitrate in water to prepare a 0.3-0.5 mol / L ceric ammonium nitrate solution.

5. The method for preparing a modified metal organic framework material according to claim 1, wherein: Zirconium nitrate solution and cerium ammonium nitrate solution were mixed in the ion ratio of Zr 4+ :Ce 4+ =3~4:1 and mix evenly to obtain a metal solution.

6. The method for preparing a modified metal organic framework material according to claim 1, characterized in that: Microwave power 220~250W.

7. A modified metal organic framework material prepared according to the preparation method according to any one of claims 1 to 6.

8. Use of the modified metal organic framework material according to claim 7 in the degradation of tetracycline in water.