Hydrophilic porphyrin-based covalent organic framework material as well as preparation method and application thereof

Abstract

The invention discloses a hydrophilic porphyrinyl covalent organic framework material as well as a preparation method and application thereof, and during preparation, 5, 10, 15, 20-tetra (4-aminophenyl) porphyrin and 3-hydroxy-[1, 2, 3]-triazolo [1, 2, 3] triazolo [1, 2, 3] triazolo [1, 2, 3] triazolo [1, the preparation method comprises the following steps: adding two monomers of o-dichlorobenzene, 1, 1 '-biphenyl]-4, 4'-dicarboxaldehyde into a glass tube, then adding a mixed solution of o-dichlorobenzene and n-butanol into the glass tube, completely dissolving under the ultrasonic action, and then adding acetic acid to catalyze the reaction; then, through liquid nitrogen freezing and air extraction and exchange, tube sealing treatment is conducted under the condition that the interior of the glass tube is kept in a negative pressure state, and heating is conducted for three days at the temperature of 120 DEG C; the preparation method comprises the following steps: reacting a porphyrin covalent organic framework material with water, generating purple precipitate after the reaction is finished, filtering the precipitate with filter paper, soaking with N, N-dimethylformamide, then carrying out Soxhlet extraction with a methanol solution, and finally carrying out vacuum drying to obtain the hydrophilic porphyrin covalent organic framework material. The material can be used for adsorption and recovery of radioactive iodine, and has efficient radioactive iodine adsorption capacity.

Description

Technical Field

[0001] The invention relates to the field of covalent organic framework materials, in particular to a hydrophilic porphyrin-based covalent organic framework material and a preparation method and application thereof. Technical Background

[0002] Covalent Organic Frameworks (COFs) are a class of organic porous crystalline materials formed by light elements connected by covalent bonds. They have the advantages of low mass density, high specific surface area, regular pores and controllable structure. These advantages make them an important material for solving global resource, environmental and energy problems.

[0003] In recent years, COFs have been widely used in the capture of radioactive iodine due to their controllable structure and targeted design.

[0004] Nuclear energy plays an important role in meeting energy needs, but environmental pollution is also an urgent problem faced by the use of nuclear energy. 129 I and 131 I) As one of the harmful radionuclides that may be produced during the operation of nuclear power plants, its effective capture is of great significance to environmental protection and human health.

[0005] At present, the main methods for treating radioactive iodine in water bodies include adsorption, precipitation, ion exchange, membrane separation, etc. Among them, adsorption to capture iodine ions from aqueous solution has the characteristics of low cost and simple operation. Summary of the invention

[0006] The purpose of the present invention is to provide a hydrophilic porphyrin-based covalent organic framework material and a preparation method thereof for the existing technology of removing radioactive iodine nuclides from water. The material can be used for adsorption of radioactive iodine in water and has the advantages of high radioactive iodine removal rate.

[0007] The first aspect of the present invention provides a method for preparing a hydrophilic porphyrin-based covalent organic framework material, the preparation route is:

[0008]

[0009] The preparation method comprises the following steps:

[0010] (1) adding two monomers, 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and 3-hydroxy-[1,1'-biphenyl]-4,4'-dicarboxaldehyde, into a glass tube, then adding a mixed solution of o-dichlorobenzene and n-butanol in a ratio of 1:1, and dissolving the two monomers completely under the action of ultrasound, and then adding acetic acid to catalyze the reaction;

[0011] (2) Freeze with liquid nitrogen, ventilate, seal the tube under negative pressure, and heat at 120°C for three days;

[0012] (3) After the heating reaction is completed, a purple precipitate is generated, which is filtered using filter paper and soaked in N,N-dimethylformamide, then Soxhlet extracted with a methanol solution, and finally vacuum dried to obtain a hydrophilic porphyrin-based covalent organic framework material, referred to as TAPP-HBD-COF.

[0013] In step (1) of the preparation method, the molar ratio of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and 3-hydroxy-[1,1'-biphenyl]-4,4'-dicarbaldehyde is 1:2, and the volume of the mixed solution of o-dichlorobenzene and n-butanol is 50 mL;

[0014] After the two monomers were completely dissolved, 5 mL of acetic acid with a molar concentration of 6 M was added and mixed thoroughly, and then the mixture was allowed to stand at 120° C. to perform a catalytic reaction.

[0015] In step (3) of the preparation method, the Soxhlet extraction temperature is 100°C, the time is 24 hours, and the vacuum drying temperature is 80°C.

[0016] In a second aspect, the present invention provides a hydrophilic porphyrin-based covalent organic framework material prepared by the above method, wherein the material has 2.25 nm ordered pores, the pores contain hydroxyl groups and a large number of nitrogen atoms, and there is interaction between the nitrogen atoms and iodide ions.

[0017] Compared with traditional materials, this material has a high efficiency in adsorbing radioactive iodine.

[0018] The third aspect of the present invention also provides the use of hydrophilic porphyrin-based covalent organic framework materials in the separation and recovery of radioactive iodine elements. Through the hydrophilicity of the hydroxyl group and the large amount of nitrogen elements contained in the porphyrin ring, the porphyrin ring interacts with iodine anions, making it a potential adsorption material for removing radioactive iodine anions in aqueous solutions.

[0019] The application method is to add the hydrophilic porphyrin-based covalent organic framework material to a 131 I in an aqueous solution and shaken at room temperature for a period of time to achieve Na 131 I adsorption is a covalent organic framework material used to adsorb authentic radioactive iodine nuclide ions in aqueous solution.

[0020] The specific test method is as follows: (1) Different masses of hydrophilic porphyrin-based covalent organic framework materials are placed at the same activity and volume to test their effects on Na 131 (2) The same mass of hydrophilic porphyrin-based covalent organic framework materials were placed in the same volume of Na 131I aqueous solution, test the same mass of Na with different radioactivity 131 (3) The same mass of hydrophilic porphyrin covalent organic framework material was placed in Na 131 I aqueous solution, respectively, at different times to test its Na 131 The removal rate of I.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The covalent organic framework material of the present invention has both hydroxyl hydrophilic groups and porphyrin ring nitrogen-rich structures. The hydroxyl groups improve the dispersibility of the material in water, while the nitrogen atoms and iodide ions form multiple binding sites through Lewis acid-base interaction, hydrogen bonding or electrostatic interaction, which significantly improves the adsorption capacity and selectivity of radioactive iodine. Experiments show that its removal rate far exceeds that of traditional adsorption materials. In the application of separation and recovery of radioactive iodine, the material is added with Na 131 I aqueous solution, room temperature shaking can achieve adsorption, easy to operate. Through a variety of test methods to verify that the material under different mass, different radioactivity and different time conditions, can be Na 131 I exhibits good removal ability, providing an effective solution to the problem of radioactive iodine pollution caused by nuclear power plants, etc., and has important environmental significance and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Roadmap for the hydrophilic porphyrin-based covalent organic framework materials prepared in Example;

[0024] Figure 2 Fourier transform infrared (FTIR) comparison diagram of TAPP-HBD-COF prepared in Example;

[0025] Figure 3 The X-ray powder diffraction (XRD) comparison spectra of TAPP-HBD-COF prepared in Example;

[0026] Figure 4 The nitrogen adsorption-desorption curve of TAPP-HBD-COF prepared in Example;

[0027] Figure 5 The TAPP-HBD-COF prepared in the example has the same activity of Na under different masses. 131 I removal rate of aqueous solution;

[0028] Figure 6 The TAPP-HBD-COF prepared in the example has the same mass and different activities of Na 131 I removal rate of aqueous solution;

[0029] Figure 7 The TAPP-HBD-COF prepared in the example has the same mass and the same activity of Na 131 I removal rate of aqueous solution at different times. DETAILED DESCRIPTION

[0030] To facilitate understanding of the present invention, the present invention is further described below with reference to specific embodiments and drawings, but the present invention is not limited thereto.

[0031] In addition, the embodiments should be understood as illustrative rather than limiting the essence and scope of the invention. Various changes or modifications to the material components and dosages in these embodiments also fall within the scope of protection of the present invention.

[0032] Raw materials used in the examples of the present invention: 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, 98%, commercially available; 3-hydroxy-[1,1'-biphenyl]-4,4'-dicarbaldehyde, 98%, commercially available; o-dichlorobenzene, analytically pure, commercially available; n-butanol, analytically pure, commercially available; acetic acid, analytically pure, commercially available.

[0033] Example:

[0034] Preparation of hydrophilic porphyrin-based covalent organic framework materials, refer to Figure 1 , including the following steps:

[0035] (1) adding two monomers, 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and 3-hydroxy-[1,1'-biphenyl]-4,4'-dicarboxaldehyde, in a molar ratio of 1:2 into a glass tube, then adding 50 mL of a mixed solution of o-dichlorobenzene and n-butanol in a ratio of 1:1, and dissolving the two monomers completely under ultrasonic action, then adding 5 mL of 6 M acetic acid and mixing them thoroughly, and then standing at 120° C. to perform a catalytic reaction;

[0036] (2) Freeze with liquid nitrogen, ventilate, seal the tube under negative pressure, and heat at 120°C for three days;

[0037] (3) After the heating reaction is completed, a purple precipitate is generated, which is filtered using filter paper and soaked in N,N-dimethylformamide, followed by Soxhlet extraction using a methanol solution at a temperature of 100°C for 24 hours, and finally vacuum dried at 80°C to obtain a hydrophilic porphyrin-based covalent organic framework material, referred to as TAPP-HBD-COF.

[0038] The obtained hydrophilic porphyrin-based covalent organic framework material was used for Na 131In the adsorption experiment, (1) 25.5 mg of TAPP-HBD-COF material was placed in 5 mL of Na 131 I in aqueous solution;

[0039] (2) 25.5 mg of TAPP-HBD-COF material was placed in 5 mL of Na 131 I in aqueous solution;

[0040] (3) 25.5 mg of TAPP-HBD-COF material was placed in 5 mL of Na 131 I aqueous solution.

[0041] The Fourier transform infrared spectra of the reaction monomer of the TAPP-HBD-COF material prepared in the embodiment and the finished product material after preparation are compared, as shown in FIG. Figure 2 As shown, the C=O vibration band (1676 cm -1 ) and the NH stretch band belonging to TAPP (3431cm -1 and 3352cm -1 ) disappeared, while the stretching vibration peak of the imine bond was observed in the FTIR spectrum of the prepared TAPP-HBD-COF, which clearly indicated the formation of covalent bonds.

[0042] The XRD spectrum of TAPP-HBD-COF prepared in Example is as follows: Figure 3 As shown, the XRD spectrum of the product exhibits two main diffraction peaks, which are attributed to the (220) and (001) crystal planes, respectively.

[0043] The nitrogen adsorption-desorption curve of TAPP-HBD-COF prepared in Example is as follows: Figure 4 As shown, the specific surface area is 65.527m 2 / g.

[0044] Effect of different masses of TAPP-HBD-COF materials prepared in the example on Na in aqueous solution 131 The removal rate of I, such as Figure 5 As shown in the figure, when the mass of TAPP-HBD-COF added was 35 mg, the radioactive Na 131 The removal rate of I was the highest, at 91%.

[0045] The same mass of TAPP-HBD-COF materials prepared in the embodiment has different activities of Na in aqueous solution. 131 The removal rate of I, such as Figure 6 As shown, TAPP-HBD-COF has a 131 The removal rate of I was kept above 80%.

[0046] The same mass of materials prepared in the embodiment has the same activity of Na in aqueous solution. 131 The removal rate of I at different times, such as Figure 7 As shown, TAPP-HBD-COF material has a 131 The removal rate of I can reach 74% within 1 hour. When the adsorption time is extended to 72h, the removal rate of Na 131 The removal rate of I can reach 94%.

[0047] The above experiments prove that the hydrophilic porphyrin-based covalent organic framework material TAPP-HBD-COF of the present invention has a strong affinity for Na 131 The adsorption performance of I is good.

[0048] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various forms of changes and modifications can still be made to the technical solutions in the embodiments based on the above description. It is not necessary and impossible to list all implementation methods here. Any modification, change, replacement, etc. made on the basis of the technical content disclosed in the present invention are equivalent to equivalent implementation cases and should be included in the protection scope of the present invention.

Claims

1. A method for preparing a hydrophilic porphyrin-based covalent organic framework material, characterized in that: The preparation route is: The preparation method comprises the following steps: (1) adding two monomers, 5,10,15,20-tetrakis(4-aminophenyl)porphyrin and 3-hydroxy-[1,1'-biphenyl]-4,4'-dicarboxaldehyde, into a glass tube, then adding a mixed solution of o-dichlorobenzene and n-butanol in a ratio of 1:1, and dissolving the two monomers completely under the action of ultrasound, and then adding acetic acid to catalyze the reaction; (2) Freeze with liquid nitrogen, ventilate, seal the tube under negative pressure, and heat at 120°C for three days; (3) After the heating reaction is completed, a purple precipitate is generated, which is filtered using filter paper and soaked in N,N-dimethylformamide, then Soxhlet extracted with a methanol solution, and finally vacuum dried to obtain a hydrophilic porphyrin-based covalent organic framework material, referred to as TAPP-HBD-COF.

2. The preparation method according to claim 1, characterized in that: In step (1) of the preparation method, the molar ratio of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin to 3-hydroxy-[1,1'-biphenyl]-4,4'-dicarbaldehyde is 1:2, and the volume of the mixed solution of o-dichlorobenzene and n-butanol is 50 mL; After the two monomers were completely dissolved, 5 mL of acetic acid with a molar concentration of 6 M was added and mixed thoroughly, and then the mixture was allowed to stand at 120° C. to perform a catalytic reaction.

3. The preparation method according to claim 1, characterized in that: In step (3) of the preparation method, the Soxhlet extraction temperature is 100°C, the time is 24 hours, and the vacuum drying temperature is 80°C.

4. A hydrophilic porphyrin-based covalent organic framework material, characterized in that: The hydrophilic porphyrin-based covalent organic framework material is prepared by the preparation method described in any one of claims 1 to 3.

5. The hydrophilic porphyrin-based covalent organic framework material according to claim 4, characterized in that: The hydrophilic porphyrin-based covalent organic framework material has 2.25nm ordered pores, the pores contain hydroxyl groups and a large number of nitrogen atoms, and there is interaction between the nitrogen atoms and iodine ions.

6. Use of the hydrophilic porphyrin-based covalent organic framework material obtained by the preparation method according to any one of claims 1 to 3, and / or the hydrophilic porphyrin-based covalent organic framework material according to claim 4 in the adsorption of radioactive iodine.

7. A radioactive iodine adsorbent, characterized in that: The radioactive iodine adsorbent at least partially comprises the hydrophilic porphyrin-based covalent organic framework material obtained by the preparation method according to any one of claims 1 to 3, and / or the hydrophilic porphyrin-based covalent organic framework material according to claim 4.

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