Magnetic nanoparticles / pillar aromatic covalent organic framework core-shell materials and their applications

Abstract

This invention discloses a magnetic nanoparticle / columnar aromatic hydrocarbon covalent organic framework (COF) core-shell material and its applications. The core-shell material uses Fe3O4 nanoparticles as the core, with a columnar aromatic hydrocarbon covalent organic framework (COF) material coating the Fe3O4 nanoparticles as the outer shell. The COF material is prepared from macrocyclic columnar aromatic hydrocarbons and tetraaminoporphyrin. The core-shell material of this invention utilizes the porosity of the COF material and the cavities of the columnar aromatic hydrocarbons to effectively adsorb organic pollutants in water. The porphyrin units degrade the adsorbed pollutants under light irradiation. The Fe3O4 nanoparticles degrade the pollutants, and the Fe3O4@P5COF core-shell material is then separated by magnetic force for recycling, thus achieving integrated adsorption, degradation, and separation.

Description

Technical Field

[0001] This invention belongs to the field of organic materials technology, specifically relating to a magnetic nanoparticle Fe3O4 / pillar aromatic covalent organic framework core-shell material and its applications. Background Technology

[0002] Porphyrins and their derivatives can generate singlet oxygen under 660 nm light irradiation. Therefore, photoinduced redox reactions occurring on the surface of porphyrin derivative materials represent a promising environmental remediation technology, particularly for the remediation of waterborne pollutants. Compared to traditional wastewater treatment methods, this technology offers advantages such as complete mineralization and high degradation efficiency for low-concentration organic matter. Furthermore, porous organic materials, such as metal-organic frameworks (MOFs) or covalent organic frameworks (COFs), possess excellent adsorption capabilities. On the other hand, columnar aromatics, as a newly emerging class of macrocyclic host compounds, are characterized by simple synthesis, rich host-guest properties, and good environmental responsiveness.

[0003] Therefore, this invention combines the advantages of these three elements to synthesize a core-shell nanoparticle based on columnar aromatic hydrocarbon COF-coated magnetic nanoparticles (Fe3O4@P5COF), and applies it to the adsorption and degradation of organic pollutants in water. Summary of the Invention

[0004] One of the objectives of this invention is to provide a Fe3O4 / pillar aromatics covalent organic framework core-shell material, with Fe3O4 nanoparticles as the core and pillar aromatics covalent organic framework material as the outer shell.

[0005] The columnar aromatic covalent organic framework material is prepared from macrocyclic columnar aromatics and tetraaminoporphyrin;

[0006] The structural formula of the macrocyclic aromatic hydrocarbon is shown below:

[0007]

[0008] The structural formula of the tetraaminoporphyrin described in this invention is shown below:

[0009]

[0010] In one embodiment of the present invention, the Fe3O4 / pillar aromatic covalent organic framework core-shell material is prepared by the following method:

[0011] Fe3O4 nanoparticles were dispersed in N,N-dimethylformamide, and macrocyclic aromatic hydrocarbons and tetraaminoporphyrin were added. The mixture was refluxed, cooled, and then magnetically separated to obtain the core-shell material Fe3O4@P5COF.

[0012] A second objective of this invention is to provide the application of the above-mentioned Fe3O4 / pillar aromatic covalent organic framework core-shell material in the adsorption and / or degradation of organic pollutants in water.

[0013] This invention utilizes macrocyclic columnar aromatics and aminoporphyrins as precursors to prepare a covalent organic framework as an outer shell, which is then coated onto a magnetic Fe3O4 core to prepare the core-shell material Fe3O4@P5COF. The porosity of the COF material and the cavities of the columnar aromatics effectively adsorb organic pollutants in water. The porphyrin units degrade the adsorbed pollutants under light irradiation. Fe3O4 nanoparticles further degrade the pollutants, and the Fe3O4@P5COF core-shell material is then separated by magnetic force for recycling, thus achieving integrated adsorption, degradation, and separation. Attached Figure Description

[0014] Figure 1 This is a TEM image of the Fe3O4@P5COF core-shell material.

[0015] Figure 2 In the figure, (a), (b), (c), (d), and (e) are the ultraviolet spectra of 0.5 mmol / L aqueous solutions of Brythromycin Y, Rhodamine B, azofluorescein, alizarin red, and methylene blue; (a'), (b'), (c'), (d'), and (e') are the graphs showing the change of maximum absorbance values ​​over time after adding Fe3O4@P5COF core-shell material to 0.5 mmol / L aqueous solutions of Brythromycin Y, Rhodamine B, azofluorescein, alizarin red, and methylene blue.

[0016] Figure 3 To be in near-infrared light (660nm, 10mW / cm) 2 The graph shows the change in maximum absorbance over time when Fe3O4@P5COF core-shell material is added to or not added to a 0.5 mmol / L aqueous solution of Brythromycin Y, Rhodamine B, azofluorescein, Alizarin Red, and methylene blue, under irradiation. Detailed Implementation

[0017] The preferred embodiments of the present invention will now be described in detail with reference to specific examples. It should be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from its spirit and essence.

[0018] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0019] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0020] In the following examples, Fe3O4 nanoparticles were prepared by a conventional solvothermal method [Langmuir, 2010, 26(3): 1674-1679].

[0021] Example 1

[0022] Preparation of Fe3O4@P5COF core-shell material

[0023] 500 mg of pre-prepared Fe3O4 nanoparticles were added to a 500 mL round-bottom flask, followed by 250 mL of N,N-dimethylformamide (DMF). After stirring at room temperature for 2 hours, macrocyclic aromatic hydrocarbons (1.8 g, 2.0 mmol) and tetraaminoporphyrin (0.67 g, 1.0 mmol) were added, and the mixture was heated to reflux. The reaction progress was monitored by thin-plate chromatography. After 3 days, the reaction was stopped once the macrocyclic aromatic hydrocarbons had completely reacted. The mixture was separated by magnetic separation and washed three times with dichloromethane to obtain the core-shell material Fe3O4@P5COF. The prepared material was characterized by transmission electron microscopy, as shown in the figure. Figure 1 As shown, Fe3O4 was successfully encapsulated inside by the columnar aromatic hydrocarbon COF.

[0024] Test Example 1

[0025] Adsorption of organic pollutants in water by Fe3O4@P5COF core-shell material

[0026] First, the UV spectrum of water containing 0.5 mmol / L of organic dyes (Bersch Brown, Rhodamine B, Azo Fluorescent Pink, Alizarin Red, and Methylene Blue) was measured using UV spectroscopy. Then, 5 mg of Fe3O4@P5COF core-shell material was added to the solution, and the UV spectra of the solution were measured after stirring for 1, 2, 3, 4, and 5 hours.

[0027] like Figure 2 As shown, after adding Fe3O4@P5COF core-shell material and stirring, the maximum absorption values ​​of the organic dyes in the ultraviolet spectrum all decreased, indicating that the organic dyes were adsorbed from the water onto the Fe3O4@P5COF core-shell material. However, after two hours, the maximum absorption value remained basically unchanged, indicating that the material adsorption reached saturation and could no longer adsorb organic dyes.

[0028] Test Example 2

[0029] Photodegradation of organic pollutants in water by Fe3O4@P5COF core-shell nanomaterials

[0030] 5 mg of Fe3O4@P5COF core-shell material was added to an aqueous solution of 0.5 mmol / L organic dyes (Bersch Brown Y, Rhodamine B, Azofluorescein, Alizarin Red, and Methylene Blue, respectively). After adsorption for 1 hour, near-infrared light (wavelength: 660 nm, power: 10 mW / cm²) was used for further analysis. 2 Under irradiation, the degradation of organic dyes was determined by ultraviolet spectroscopy.

[0031] like Figure 3 As shown, under near-infrared light irradiation, the maximum absorbance of the organic dye continuously decreases until it eventually disappears, proving that the Fe3O4@P5COF core-shell material can effectively adsorb and degrade organic dyes under light irradiation. In contrast, without the addition of Fe3O4@P5COF core-shell material, the maximum absorbance of the organic dye under near-infrared light irradiation does not decrease, demonstrating that near-infrared light alone cannot degrade it. After the dye degrades, the Fe3O4@P5COF core-shell material can be reused after magnetic separation, washing, and drying.

Claims

1. A magnetic nanoparticle / pillar aromatic covalent organic framework core-shell material, with Fe3O4 nanoparticles as the core and pillar aromatic covalent organic framework material as the outer shell covering the Fe3O4 nanoparticles; The columnar aromatic covalent organic framework material is prepared from macrocyclic columnar aromatics and tetraaminoporphyrin; The structural formula of the macrocyclic aromatic hydrocarbon is shown below: ， The structural formula of the tetraaminoporphyrin is shown below: 。 2. The method for preparing the magnetic nanoparticle / pillar aromatic covalent organic framework core-shell material according to claim 1, characterized in that, Fe3O4 nanoparticles were dispersed in N,N-dimethylformamide, macrocyclic aromatic hydrocarbons and tetraaminoporphyrin were added, the mixture was refluxed, cooled, and then magnetically separated to obtain the core-shell material.

3. The application of the magnetic nanoparticle / pillar aromatic covalent organic framework core-shell material according to claim 1 in the adsorption and / or degradation of organic pollutants in water.

Images