Anti-interference silver-vanadium metal-organic framework derivative material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of treatment of pollutants in wastewater, in particular to an anti-interference silver-vanadium metal-organic framework derivative material as well as a preparation method and application thereof. The preparation method comprises the steps that firstly, an AgV-MOF material with a two-dimensional twisted wave layered structure is prepared, then an Ag / V-MOF derivative material is prepared through alkaline etching, the Ag / V-MOF derivative material is provided with the wrinkled two-dimensional twisted wave layered structure, a large number of-OH groups are attached to the surface, and the Ag / V-MOF derivative material is prepared. Silver ions and vanadium ions can form an electron transfer path through bridging of organic ligands, so that electron transmission and transfer in the material are facilitated, and the adsorption performance of active sites of the material is further improved; therefore, the Ag / V-MOF derivative material can present the characteristics of high efficiency, short time and strong anti-interference performance when adsorbing creatinine under the combined action of the charge on the surface of the material, the conjugated structure of the ligand, electron transfer of the metal center and the two-dimensional twisted wave layered structure with the folds.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater pollutant treatment, and in particular to an anti-interference silver-vanadium metal-organic framework derivative material and a preparation method and application thereof. Background Art

[0002] Hemodialysis removes uremic toxins from the patient's blood, such as creatinine (CA), uric acid and urea. Creatinine is a nitrogen-containing five-membered ring with a nitrogen content of up to 40%. If it is discharged into the water environment in large quantities with dialysis water without treatment, it will cause environmental pollution such as eutrophication.

[0003] Bimetallic-organic frameworks (MOFs) are a type of crystal structure composed of two different metal ions and organic ligands, with the following characteristics: synergistic catalysis is achieved through metal synergy; bimetallic MOFs can adjust their structure and properties by selecting different metals and organic ligands; bimetallic MOFs can regulate the size and shape of microscopic pores by changing the combination of metal ions and organic ligands; the metal ions in bimetallic MOFs can form electron transport channels.

[0004] It can be seen that bimetallic-organic framework materials have diverse metal centers and modifiability, and therefore are widely used in catalysis, adsorption, gas separation, energy storage and other fields; however, there have been no reports on the adsorption treatment of creatinine.

[0005] Therefore, the applicant designed a novel structure of Ag / V-MOF derivative material in the category of bimetallic-organic framework materials to solve the adsorption problem of creatinine. Summary of the invention

[0006] In order to achieve the above-mentioned purpose, the present invention designs an anti-interference type silver-vanadium bimetallic-organic framework derivative material, which can show the characteristics of high efficiency, short time and strong anti-interference performance when adsorbing creatinine through the combined effects of the surface charge of the material, the conjugated structure of the ligand, the electron transfer of the metal center and the wrinkled two-dimensional twisted wavy layered structure on the surface.

[0007] For the convenience of description, the anti-interference silver-vanadium bimetallic-organic framework derivative material designed by the present invention is hereinafter referred to as an Ag / V-MOF derivative material. The Ag / V-MOF derivative material is prepared based on the AgV-MOF material by alkaline treatment. The structure of the unit cell of the AgV-MOF material is as follows:

[0008]

[0009] The unit cell is an asymmetric structural unit containing one silver atom, three vanadium atoms, one tris(4-(1H-1,2,4-triimidazole)phenyl)amine, and eight oxygen atoms;

[0010] The silver atom has a coordination number of 2 and presents a linear structure, coordinated with two N atoms from tris(4-(1H-1,2,4-triimidazole)phenyl)amine;

[0011] Among the three vanadium atoms, the one adjacent to tri(4-(1H-1,2,4-triimidazole)phenyl)amine forms a {VNO4} tetrahedral vanadium oxy-cluster, and the two vanadium atoms far away from tri(4-(1H-1,2,4-triimidazole)phenyl)amine coordinate with oxygen atoms respectively to form a {VO4} tetrahedral vanadium oxy-cluster.

[0012] Furthermore, the AgV-MOF material belongs to the triclinic system, P-1 space group, and the volume of its unit cell is The length of the unit cell is: The angles of the unit cell are: α = 73.2775°, β = 79.4578°, γ = 78.4595°.

[0013] Furthermore, the surface of the Ag / V-MOF-derived material has a wrinkled two-dimensional twisted wavy layered structure and possesses the characteristics of a bimetallic complex: silver ions and vanadium ions can be bridged by tri(4-(1H-1,2,4-triimidazole)phenyl)amine as an organic ligand, forming an electron transfer pathway based on the single-electron characteristics of vanadium oxyclusters.

[0014] Note: After the alkaline solution etching treatment, a large number of -OH groups are introduced to the surface of the material, which changes the surface electrical properties of the material and increases the isoelectric point of the material from 5.35 to 10.70; secondly, see Figure 2 , 3 From the SEM image, it can be seen that the surface of the treated material becomes wrinkled, which further increases the specific surface area of ​​the derivative material by about 300%. Based on the above structural characteristics, the isoelectric point range of the Ag / V-MOF derivative material is 10.6-10.7, and the specific surface area range is: 1.7766-3.6027m 2 / g.

[0015] The present invention also designs a method for preparing Ag / V-MOF derivative materials, the steps comprising:

[0016] S1. Preparation of AgV-MOF materials;

[0017] S1-1, firstly, adding tri(4-(1H-1,2,4-triimidazole)phenyl)amine, ammonium metavanadate and silver nitrate into pure water and mixing them evenly to obtain a first mixed solution, and then adjusting the pH value of the first mixed solution to 3.5;

[0018] Let n be the multiplication coefficient and n∈R +, when the amount of tri(4-(1H-1,2,4-triimidazole)phenyl)amine added in S1-1 is 1 nmol, the amount of ammonium metavanadate added is [4.5n, 6n]mol, the amount of silver nitrate added is [3n, 5n]mol, and the amount of pure water added is [9n, 10n]L;

[0019] S1-2, reacting the mixed solution in S1-1 at 150°C for 48 to 96 hours, and cooling to room temperature at a rate of -10°C / h after the reaction to obtain a two-dimensional twisted wavy layered structure of AgV-MOF material;

[0020] S2, preparing Ag / V-MOF derived materials;

[0021] S2-1, first grind and crush the AgV-MOF material in S1-1, evenly disperse it in pure water and ultrasonically vibrate it for 10 to 20 minutes, then add 3M NaOH solution and continue stirring for 1 to 1.5 hours to obtain a second mixed solution;

[0022] Let n be the multiplication coefficient and n∈R + , when the amount of AgV-MOF material added in S2-1 is 1 ng, the amount of pure water added is [100n, 110n] mL, and the amount of 3M NaOH solution added is [100n, 110n] mL;

[0023] S2-2. First, filter the second mixed liquid to obtain a filter residue, and wash the filter residue with pure water until the washing liquid is neutral; then dry the washed filter residue at 60° C. for 1.5 to 2 hours to obtain an Ag / V-MOF derivative material.

[0024] The present invention also designs the application of Ag / V-MOF derivative materials to adsorb creatinine in wastewater. Under the following reaction conditions, when the dosage of Ag / V-MOF derivative materials is 0.2 g / L, the maximum adsorption amount of creatinine in wastewater is 140 mg / g.

[0025] The reaction conditions are: temperature range is 15-45℃; adsorption time is 180min, pH range is 5-11, and the interferences in the wastewater include and one or more of humic acids.

[0026] Compared with the existing creatinine adsorption materials, the present invention has the following beneficial effects:

[0027] (1) The Ag / V-MOF derivative material prepared by the present invention has bimetallic properties. Silver ions and vanadium ions can form an electron transfer pathway through organic ligand bridging, which is beneficial to the electron transport and transfer inside the material, thereby improving the adsorption performance of the active sites of the material.

[0028] (2) The Ag / V-MOF derivative material prepared by the present invention has high efficiency, short time and strong anti-interference performance when used for adsorbing creatinine. It can still maintain a high adsorption efficiency in an environment with multiple interferences, and the adsorption amount of creatinine can reach 140 mg / g within 180 minutes.

[0029] (3) The synthetic process and method designed by the present invention maximize the utilization rate of reaction substrates, reduce the generation of waste and by-products, and have atom economy; moreover, the waste generated during the synthetic process should be controllable and have no negative impact on the environment, thus meeting the concept advocated by green technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a coordination environment diagram of the AgV-MOF material in Example 1 of the present invention;

[0031] Figure 2 is a SEM image of the AgV-MOF material morphology in Example 1 of the present invention;

[0032] Figure 3 is a SEM image of the Ag / V-MOF derived material in Example 1 of the present invention;

[0033] Figure 4 is a graph of the adsorption amount of the Ag / V-MOF derivative material when removing creatinine by adsorption in the experimental example of the present invention;

[0034] Figure 5 This is an anti-interference test diagram of the Ag / V-MOF derivative material when removing creatinine by adsorption under independent interference conditions in the experimental example of the present invention;

[0035] Figure 6 This is an anti-interference test diagram of the Ag / V-MOF derivative material when removing creatinine by adsorption under mixed interference conditions in the experimental example of the present invention;

[0036] Figure 7 is a graph showing the adsorption of creatinine by the Ag / V-MOF derivative material in different pH ranges in the experimental examples of the present invention;

[0037] Figure 8 This is a test diagram of the recyclability of Ag / V-MOF derived materials in the experimental example of the present invention. DETAILED DESCRIPTION

[0038] In order to further illustrate the method and effect of the present invention, the technical solution of the present invention will be clearly and completely described in combination with experiments.

[0039] Example 1: This example describes a method for preparing an anti-interference silver-vanadium bimetallic-organic framework derivative material.

[0040] S1. Preparation of AgV-MOF materials;

[0041] S1-1, firstly, adding tri(4-(1H-1,2,4-triimidazole)phenyl)amine, ammonium metavanadate and silver nitrate into pure water and mixing them evenly to obtain a first mixed solution, and then adjusting the pH value of the first mixed solution to 3.5;

[0042] When the amount of tri(4-(1H-1,2,4-triimidazole)phenyl)amine added in S1-1 is 0.1 mol, the amount of ammonium metavanadate added is 0.4 mol, the amount of silver nitrate added is 0.3 mol, and the amount of pure water added is 9 L;

[0043] S1-2, reacting the mixed solution in S1-1 at 150°C for 96 hours, and cooling to room temperature at a rate of -10°C / h after the reaction to obtain a two-dimensional twisted wavy layered structure of AgV-MOF material;

[0044] S2, preparing Ag / V-MOF derived materials;

[0045] S2-1, first grind and crush the AgV-MOF material in S1-1, evenly disperse it in pure water and ultrasonically vibrate it for 20 minutes, then add 3M NaOH solution and continue stirring for 1.5 hours to obtain a second mixed solution;

[0046] When the amount of AgV-MOF material added in S2-1 was 10 g, the amount of pure water added was 1.1 L, and the amount of 3 M NaOH solution added was 1.1 L;

[0047] S2-2. First, filter the second mixed liquid to obtain a filter residue, and wash the filter residue with pure water until the washing liquid is neutral; then dry the washed filter residue at 60°C for 2 hours to obtain an Ag / V-MOF derivative material, i.e., an anti-interference silver-vanadium bimetallic-organic framework derivative material.

[0048] Specifically, the structure of the unit cell of the AgV-MOF material prepared in S1 is:

[0049]

[0050] The unit cell is an asymmetric structural unit containing one silver atom, three vanadium atoms, one tris(4-(1H-1,2,4-triimidazole)phenyl)amine, and eight oxygen atoms;

[0051] The silver atom has a coordination number of 2 and presents a linear structure, coordinated with two N atoms from tris(4-(1H-1,2,4-triimidazole)phenyl)amine;

[0052] Among the three vanadium atoms, the one adjacent to tri(4-(1H-1,2,4-triimidazole)phenyl)amine forms a {VNO4} tetrahedral vanadium oxy-cluster, and the two vanadium atoms far away from tri(4-(1H-1,2,4-triimidazole)phenyl)amine coordinate with oxygen atoms respectively to form a {VO4} tetrahedral vanadium oxy-cluster.

[0053] Specifically, the Ag / V-MOF derivative material prepared in S2 is a two-dimensional twisted wavy layered structure with wrinkles on the surface, and has the characteristics of a bimetallic complex: silver ions and vanadium ions can be bridged by tris(4-(1H-1,2,4-triimidazole)phenyl)amine as an organic ligand, forming an electron transfer pathway based on the single-electron characteristics of vanadium oxygen clusters;

[0054] The isoelectric point range of the Ag / V-MOF derived material in this embodiment is 10.7, and the specific surface area range is: 3.6027m 2 / g.

[0055] Example 2: This example describes a method for preparing an anti-interference silver-vanadium bimetallic-organic framework derivative material.

[0056] S1. Preparation of AgV-MOF materials;

[0057] S1-1, firstly, adding tri(4-(1H-1,2,4-triimidazole)phenyl)amine, ammonium metavanadate and silver nitrate into pure water and mixing them evenly to obtain a first mixed solution, and then adjusting the pH value of the first mixed solution to 3.5;

[0058] When the amount of tri(4-(1H-1,2,4-triimidazole)phenyl)amine added in S1-1 is 0.1 mol, the amount of ammonium metavanadate added is 0.6 mol, the amount of silver nitrate added is 0.5 mol, and the amount of pure water added is 10 L;

[0059] S1-2, reacting the mixed solution in S1-1 at 150°C for 48 hours, and cooling to room temperature at a rate of -10°C / h after the reaction to obtain a two-dimensional twisted wavy layered structure of AgV-MOF material;

[0060] S2, preparing Ag / V-MOF derived materials;

[0061] S2-1, first grind and crush the AgV-MOF material in S1-1, evenly disperse it in pure water and ultrasonically vibrate it for 10 minutes, then add 3M NaOH solution and continue stirring for 1 hour to obtain a second mixed solution;

[0062] When the amount of AgV-MOF material added in S2-1 was 10 g, the amount of pure water added was 1 L, and the amount of 3M NaOH solution added was 1 L;

[0063] S2-2. First, filter the second mixed liquid to obtain a filter residue, and wash the filter residue with pure water until the washing liquid is neutral; then dry the washed filter residue at 60°C for 1.5 hours to obtain an Ag / V-MOF derivative material, i.e., an anti-interference silver-vanadium bimetallic-organic framework derivative material.

[0064] Specifically, the structure of the unit cell of the AgV-MOF material prepared in S1 is:

[0065]

[0066] The unit cell is an asymmetric structural unit containing one silver atom, three vanadium atoms, one tris(4-(1H-1,2,4-triimidazole)phenyl)amine, and eight oxygen atoms;

[0067] The silver atom has a coordination number of 2 and presents a linear structure, coordinated with two N atoms from tris(4-(1H-1,2,4-triimidazole)phenyl)amine;

[0068] Among the three vanadium atoms, the one adjacent to tri(4-(1H-1,2,4-triimidazole)phenyl)amine forms a {VNO4} tetrahedral vanadium oxy-cluster, and the two vanadium atoms far away from tri(4-(1H-1,2,4-triimidazole)phenyl)amine coordinate with oxygen atoms respectively to form a {VO4} tetrahedral vanadium oxy-cluster.

[0069] Specifically, the Ag / V-MOF derivative material prepared in S2 is a two-dimensional twisted wavy layered structure with wrinkles on the surface, and has the characteristics of a bimetallic complex: silver ions and vanadium ions can be bridged by tris(4-(1H-1,2,4-triimidazole)phenyl)amine as an organic ligand, forming an electron transfer pathway based on the single-electron characteristics of vanadium oxygen clusters;

[0070] The isoelectric point range of the Ag / V-MOF derivative material in this embodiment is 10.6, and the specific surface area range is: 1.7766m 2 / g.

[0071] Experimental Example: The description of this experimental example is based on the scheme described in Example 1, and is intended to illustrate the practical application effect of the present invention.

[0072] 1) Unit cell parameters

[0073] The AgV-MOF material prepared in Example 1 belongs to the triclinic system, P-1 space group, and the volume of its unit cell is The length of the unit cell is: The angles of the unit cell are: α = 73.2775°, β = 79.4578°, γ = 78.4595°.

[0074] 2) Adsorption performance

[0075] The Ag / V-MOF derivative material prepared in Example 1 is used to directly adsorb and remove creatinine (CA) in water. The specific operation process is as follows:

[0076] In order to compare the adsorption performance of Ag / V-MOF derived materials at different dosages, the following experimental groups were designed:

[0077] Group A: 25mg / L, Group B: 50mg / L, Group C: 75mg / L, Group D, 100mg / L; Group E, 125mg / L, Group F: 150mg / L.

[0078] According to the experimental design, the Ag / V-MOF derivative material was weighed and placed in the reactor, and 50 mL of CA solution was added. The adsorption experiment was carried out in a constant temperature water bath oscillator at 180 rpm / min and 45 °C. At regular intervals, 2 mL of the reaction solution was taken and filtered with a 0.22 μm filter membrane. The experimental time was 180 min.

[0079] The concentration changes were measured by high performance liquid chromatography. The degradation rate was calculated by the formula, where c0 and ct were the mass concentrations of the solution before and after adsorption, respectively, in mg / L, and qt was the adsorption amount, in mg / g.

[0080] When the Ag / V-MOF derivative material prepared in Example 1 was used to adsorb CA, the adsorption capacity of group F could reach 140 mg / g at 180 min (see Figure 4 ).

[0081] 2) Applicable pH range of Ag / V-MOF derivative materials

[0082] 1) When the Ag / V-MOF derivative material adsorbed creatinine, the pH value of the reaction system solution was adjusted to 3-11, which verified that the Ag / V bimetallic MOF derivative material could still exert a good adsorption and removal effect in the range of 5-11 (see Figure 7 ).

[0083] 3) Material anti-interference performance

[0084] 1) Add 10mmol / L interfering ions during the adsorption of CA by Ag / V-MOF derivative materials: and 10mg / L humic acid (HA); when interfering substances exist alone or in combination, the material can still maintain good adsorption performance, proving that the material has strong anti-interference ability (see Figures 5-6 ).

[0085] 4) Material recycling performance

[0086] After each experimental run, the Ag / V-MOF-derived material was separated from the reaction solution for reusability testing. The material was recycled for 5 times and the adsorption capacity of CA was still up to 90 mg / g (see Figure 8 ).

Claims

1. Anti-interference silver-vanadium bimetallic-organic framework derived material, characterized in that: The anti-interference silver-vanadium bimetallic-organic framework derivative material is an Ag / V-MOF derivative material, and the Ag / V-MOF derivative material is prepared based on the AgV-MOF material by alkaline treatment. The structure of the unit cell of the AgV-MOF material is as follows: The unit cell is an asymmetric structural unit, which contains one silver atom, three vanadium atoms, one tris(4-(1H-1,2,4-triimidazole)phenyl)amine and eight oxygen atoms; The silver atom has a coordination number of 2 and presents a linear structure, coordinated with two N atoms from tris(4-(1H-1,2,4-triimidazole)phenyl)amine; Among the three vanadium atoms, the one adjacent to tri(4-(1H-1,2,4-triimidazole)phenyl)amine forms a {VNO4} tetrahedral vanadium oxy-cluster, and the two vanadium atoms away from tri(4-(1H-1,2,4-triimidazole)phenyl)amine are coordinated with oxygen atoms to form a {VO4} tetrahedral vanadium oxy-cluster.

2. The anti-interference silver-vanadium bimetallic-organic framework derivative material according to claim 1, characterized in that: The AgV-MOF material belongs to the triclinic system, P-1 space group, and the volume of its unit cell is The length of the unit cell is: The angles of the unit cell are: α = 73.2775°, β = 79.4578°, γ = 78.4595°.

3. The anti-interference silver-vanadium bimetallic-organic framework derivative material according to claim 1, characterized in that: The Ag / V-MOF derived material has a wrinkled two-dimensional twisted wavy layered structure on its surface and possesses the characteristics of a bimetallic complex: silver ions and vanadium ions can be bridged by tris(4-(1H-1,2,4-triimidazole)phenyl)amine as an organic ligand to form an electron transfer pathway based on the single-electron characteristics of vanadium oxygen clusters.

4. A method for preparing an anti-interference silver-vanadium bimetallic-organic framework derivative material, characterized in that: The preparation method for preparing the Ag / V-MOF derivative material according to claim 1 comprises the following steps: S1. Preparation of AgV-MOF materials; S1-1, firstly, adding tri(4-(1H-1,2,4-triimidazole)phenyl)amine, ammonium metavanadate and silver nitrate into pure water and mixing them evenly to obtain a first mixed solution, and then adjusting the pH value of the first mixed solution to 3.5; Let n be the multiplication coefficient and n∈R + , when the amount of tri(4-(1H-1,2,4-triimidazole)phenyl)amine added in S1-1 is 1 nmol, the amount of ammonium metavanadate added is [4.5n, 6n] mol, the amount of silver nitrate added is [3n, 5n] mol, and the amount of pure water added is [9n, 10n] L; S1-2, reacting the mixed solution in S1-1 at 150°C for 48 to 96 hours, and cooling to room temperature at a rate of -10°C / h after the reaction to obtain a two-dimensional twisted wavy layered structure of AgV-MOF material; S2, preparing Ag / V-MOF derived materials; S2-1, first grind and crush the AgV-MOF material in S1-1, evenly disperse it in pure water and ultrasonically vibrate it for 10 to 20 minutes, then add 3M NaOH solution and continue stirring for 1 to 1.5 hours to obtain a second mixed solution; Let n be the multiplication coefficient and n∈R + , when the amount of AgV-MOF material added in S2-1 is 1 ng, the amount of pure water added is [100n, 110n] mL, and the amount of 3M NaOH solution added is [100n, 110n] mL; S2-2, first filter the second mixed liquid to obtain a filter residue, and wash the filter residue with pure water until the washing liquid is neutral; then dry the washed filter residue at 60° C. for 1.5 to 2 hours to obtain an Ag / V-MOF derivative material.

5. Application of the anti-interference silver-vanadium bimetallic-organic framework derivative material, based on the Ag / V-MOF derivative material according to claim 1, characterized in that: The Ag / V-MOF derived material is used to adsorb creatinine in wastewater.

6. The use of the anti-interference silver-vanadium bimetallic-organic framework derivative material as claimed in claim 5, characterized in that: The Ag / V-MOF derivative material is used to adsorb creatinine in wastewater under an interference environment, wherein the interference environment comprises and one or more disruptors in humic acid.

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