Magnetic porous organic polymer material and preparation and adsorption application thereof

Abstract

The invention discloses a magnetic porous organic polymer material as well as preparation and adsorption application thereof, and belongs to the technical field of functional materials. The magnetic porous organic polymer material is prepared by adopting the processes of KH570 interface modification, construction of a porous network by vinyl aniline polymerization and gallic acid covalent grafting. A KH570 silanization interface layer is constructed on the surface of the Fe3O4 coated SiO2 magnetic core so as to enhance the organic-inorganic phase interface bonding force; a through mesoporous network is formed through vinyl aniline free radical polymerization, gallic acid is covalently grafted through diazotization reaction, high-density phenolic hydroxyl groups and a pi-pi conjugated structure are introduced, and multi-mechanism synergistic adsorption of fluorine ions and organic dye is achieved. Therefore, the functional limitation of a traditional azo reaction material is broken through, and a new scheme is provided for synchronous removal of multiple pollutants in a complex wastewater system.

Description

Technical Field

[0001] The present invention relates to the technical field of functional materials, and in particular to a magnetic porous organic polymer material and its preparation and adsorption application. Background Art

[0002] Fluoride ion and organic dye pollution are important environmental issues that threaten the safety of drinking water. Long-term intake of excessive fluoride ions can lead to diseases such as dental fluorosis and skeletal fluorosis. Organic dyes are usually highly carcinogenic and can be enriched through the food chain, causing long-term genetic damage. At present, the technologies for removing fluoride or organic dyes mainly include precipitation, electrochemical and adsorption methods. Among them, the adsorption method has attracted much attention due to its simple operation and low cost. However, traditional adsorption materials such as activated alumina and hydroxyapatite have problems such as low adsorption capacity, narrow pH range, and poor regeneration efficiency. Although the magnetic porous materials based on azo reactions developed in recent years can improve the convenience of recycling through magnetic separation, they still face problems such as structural stability defects and low mass transfer efficiency.

[0003] In the field of fluoride ion removal, Chinese invention patent publication number CN104148004A discloses a magnetic fluoride ion adsorbent and its preparation method. The adsorbent components include Fe₃O₄, a ZrO₂-CeO₂ complex, and La₂(C₂O₄)₃. The preparation method involves dispersing SiO₂-modified nano-Fe₃O₄ and an additive in deionized water containing ammonia and ethanol. After ultrasonication and stirring to achieve uniform mixing, ZrOCl₂·8H₂O and Ce(NO₃)₃·6H₂O are added. After the reaction, lanthanum nitrate is added, mixed thoroughly, and oxalic acid solution is added dropwise. Finally, the product is collected with a magnet, washed, and dried. The resulting adsorbent has a regular morphology, a high adsorption capacity for fluoride ions in water, and possesses magnetic properties. This facilitates solid-liquid separation by magnetic force, both during preparation and in practical applications.

[0004] In the field of organic dye removal, Chinese invention patent publication number CN107456960A discloses a Fe3O4@SiO2@CS magnetic adsorption material and its preparation method. First, a SiO2 shell is coated on the surface of Fe3O4 to synthesize core-shell magnetic nanospheres, Fe3O4@SiO2. The Fe3O4@SiO2 is placed in a diazo resin solution and stirred at room temperature in a dark environment for 3.5-4.5 hours. After separation, the product is placed in a chitosan solution and stirred at room temperature in a dark environment for 3.5-4.5 hours. The product is then washed, separated, dried, and exposed to ultraviolet light for 10-20 minutes. This preparation method uses a photosensitive polymer diazo resin as a crosslinker to attach chitosan to the surface of the Fe3O4@SiO2 nanospheres. Upon illumination, hydrogen bonds between the silanol groups are converted to covalent bonds, resulting in stable chitosan attachment to the microsphere surface. The resulting magnetic material, Fe3O4@SiO2@CS, exhibits excellent methyl orange adsorption properties.

[0005] At present, the main technical problem of related magnetic adsorption materials in the field is the single function. Due to the limitations of its adsorption mechanism, an adsorption material can often only specifically adsorb one or a few pollutants of the same type. The development of a magnetic material with the ability to adsorb fluoride ions and organic dyes can take into account both cost control optimization and the expansion of adaptability to complex environments. Enabling the same material to have the adsorption capacity of two pollutants with different properties, fluoride ions and organic dyes, is still a technical obstacle that needs to be overcome. In addition, driven by the concept of green circular economy, the two pollutants have potential recycling value. Realizing the selective analysis of adsorbent materials is also of great significance for the recovery of pollutants and the regeneration of adsorption materials. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, in a first aspect of the present invention, a method for preparing a magnetic porous organic polymer (MPOP) material is provided, which has a convenient process, a wide range of raw material sources, and is suitable for scale-up production. The method comprises the following steps: (1) Fe3O4@SiO2 magnetic spheres were dispersed in an alcohol-water solution, KH570 and ammonia were added to adjust the pH to alkaline and react, and the product was recovered and purified to obtain Fe3O4@SiO2@KH570; (2) The obtained Fe3O4@SiO2@KH570 was dispersed in N,N-dimethylformamide (DMF), 4-vinylaniline and 2,2'-Azobis(2-methylpropionitrile) (AIBN) were added, and the polymerization reaction was carried out under an inert atmosphere. The product was recovered and purified to obtain Fe3O4@SiO2@KH570-AS; (3) The obtained Fe3O4@SiO2@KH570-AS was dispersed in an alcohol-water solution, and hydrochloric acid was added to adjust the pH to acidic under ice bath conditions, followed by addition of sodium nitrite solution and reaction. Gallic acid was then added to adjust the pH to a certain range, and an ice bath reaction (azo reaction) was carried out. The product was recovered and purified to obtain a magnetic porous organic polymer material.

[0007] Preferably, in step (1), the preparation method of Fe3O4@SiO2 magnetic spheres is as follows: dissolving FeCl3·6H2O and FeCl2·4H2O in an alcohol aqueous solution, adding ammonia water and carrying out a hydrothermal reaction under an inert atmosphere, recovering and purifying the product to obtain Fe3O4 magnetic spheres; dispersing them in an alcohol aqueous solution, adding tetraethoxysilane and ammonia water to carry out a hydrolysis condensation reaction, recovering and purifying the product to obtain Fe3O4@SiO2 magnetic spheres.

[0008] Further preferably, in the hydrothermal reaction, the amount of FeCl3·6H2O added is 13~27 g, and the molar ratio of FeCl3·6H2O to FeCl2·4H2O is 2:1; the alcohol aqueous solution is a mixture of ethanol and water with a volume ratio of 2~4:1, and the amount of alcohol aqueous solution added is 100~200 mL; the concentration of ammonia water is 28 wt.%, and the amount thereof added is 4~10 mL; in the hydrolysis condensation reaction, the amount of tetraethoxysilane added is 0.5~2 mL; the concentration of ammonia water is 28 wt.%, and the amount thereof added is 1~4 mL.

[0009] More preferably, the temperature of the hydrothermal reaction is 60-85° C., and the reaction time is 0.5-2 h; the temperature of the hydrolysis-condensation reaction is room temperature, and the reaction time is 6-12 h.

[0010] The Fe3O4@SiO2 magnetic balls in the steps can be made of commercially available or homemade materials, both of which can meet the preparation requirements of the present invention.

[0011] Preferably, in step (1), the alcohol-water solution is a mixture of ethanol and water in a volume ratio of 2 to 5:1.

[0012] Preferably, in step (1), the amount of KH570 added is 10 wt.% to 20 wt.% of the Fe3O4@SiO2 magnetic spheres.

[0013] Preferably, in step (1), aqueous ammonia is added to adjust the pH to 9-10; the reaction temperature is 25-45°C, and the reaction time is 6-12 h.

[0014] Preferably, in step (2), the mass ratio of 4-vinylaniline to Fe3O4@SiO2@KH570 is 2:1; and the amount of azobisisobutyronitrile added is 0.5 wt.% to 2 wt.% of 4-vinylaniline.

[0015] Preferably, in step (2), the polymerization reaction temperature is 65-90°C, and the reaction time is 6-12 h.

[0016] Preferably, in step (3), the alcohol-water solution is a mixture of ethanol and water in a volume ratio of 1 to 3:1.

[0017] Preferably, in step (3), hydrochloric acid is added to adjust the pH to 3-4, and the reaction time is 0.5-2 h.

[0018] Preferably, in step (3), the molar ratio of sodium nitrite to Fe3O4@SiO2@KH570-AS in the sodium nitrite solution is 1-1.5:1.

[0019] Preferably, in step (3), the mass ratio of gallic acid to Fe3O4@SiO2@KH570-AS is 1:1.5~2.5.

[0020] Preferably, in step (3), the pH is adjusted to 8-9 by sodium hydroxide; and the ice bath reaction time is 6-12 h.

[0021] In the second aspect of the present invention, a magnetic porous organic polymer material having both fluoride ion and organic dye adsorption properties and selective desorption is provided, which is prepared by the preparation method of the first aspect of the present invention.

[0022] In the third aspect of the present invention, there is provided an application of the magnetic porous organic polymer material according to the second aspect of the present invention, specifically an application as a functional material in the adsorption of fluoride ions and organic dyes.

[0023] Preferably, the magnetic porous organic polymer material is used to adsorb fluoride ions in an environment of pH=3-6, and is used to adsorb cationic organic dyes in an environment of pH=7-11.

[0024] Further preferably, after adsorption, depending on the type of pollutant, sodium hydroxide ethanol solution is used to desorb fluoride ions and recover the magnetic porous organic polymer material, and hydrochloric acid ethanol solution is used to desorb cationic organic dyes and recover the magnetic porous organic polymer material.

[0025] Based on the above technical solutions, the design concept and principle of the present invention are as follows: This invention prepares a magnetic porous organic polymer material using a process involving KH570 interface modification, vinylaniline polymerization to construct a porous network, and covalent grafting of gallic acid. A KH570 silanized interface layer is constructed on the surface of the Fe3O4@SiO2 magnetic core to enhance the organic-inorganic interface bonding. A perforated mesoporous network is formed through free radical polymerization of vinylaniline, and gallic acid is covalently grafted via a diazotization reaction. This introduces a high density of phenolic hydroxyl groups and a π-π conjugated structure, enabling multi-mechanistic synergistic adsorption of fluoride ions (via hydrogen bonding / coordination) and organic dyes (via π-π stacking / electrostatic interactions). This overcomes the functional limitations of traditional azo-reactive materials and provides a new solution for the simultaneous removal of multiple pollutants from complex wastewater systems.

[0026] Under actual use conditions such as wastewater adsorption, the magnetic porous organic polymer material is generally applicable to wastewater systems with a pH of 3 to 11, and has a wide application threshold. Under a pH of 3 to 6, the magnetic porous organic polymer material utilizes the protonation of the surface phenolic hydroxyl group (-OH2 + ) and F - The material binds through hydrogen bonding and coordination. At a pH of 7-11, the negatively charged surface of the material attracts cationic dyes (such as methylene blue) through electrostatic attraction, while π-π stacking enhances adsorption. Following adsorption, selective desorption using acid or alkaline solutions allows for material regeneration.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention provides a method for preparing a magnetic porous organic polymer material, which has the advantages of convenient process, wide source of raw materials, and suitability for expanded production.

[0028] The present invention provides a magnetic porous organic polymer material that has both fluoride ion and organic dye adsorption properties, achieves selective analysis, and has good economy and regeneration properties.

[0029] The present invention provides an application of a magnetic porous organic polymer material, expands the applicable surface of adsorption in wastewater and other environments, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of Fe3O4@SiO2@KH570-As and MPOP; Figure 2The fourier transform infrared spectroscopy (FT-IR) images of Fe3O4@SiO2@KH570, Fe3O4@SiO2@KH570-As and MPOP are shown in Figure 1. Figure 3 The pore size distribution and adsorption-desorption isotherm of MPOP Figure 4 is the X-ray diffraction (XRD) pattern of Fe3O4@SiO2@KH570 and MPOP; Figure 5 This is a transmission electron microscope (TEM) image of MPOP; Figure 6 MPOP is the effect of methylene blue (MB) and F under different pH conditions. - Adsorption capacity and desorption test results; Figure 7 MPOP is the effect of MB and F at different times - adsorption capacity. DETAILED DESCRIPTION

[0031] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0032] Example 1 Preparation method of magnetic porous organic polymer material, such as Figure 1 As shown, the steps are as follows: (1) 500 mg of core-shell Fe3O4@SiO2 magnetic nanoparticles were weighed and dispersed in a mixed solvent of 150 mL of ethanol and water (3:1, v / v), stirred and dispersed in a water bath at 40 °C, and then 1.5 mL of ammonia water (30 wt.%) and 1 mL of KH570 silane coupling agent were added and reacted for 12 h. After the reaction, the reaction solution was magnetically separated, and the precipitate was washed with water and ethanol until neutral, and then vacuum dried to obtain 450 mg of Fe3O4@SiO2@KH570. (2) 450 mg of Fe3O4@SiO2@KH570 was dispersed in 150 mL of DMF solvent and placed in a 250 mL three-necked flask with stirring and dispersion. Then, nitrogen atmosphere was introduced. 4.19 mmol / L 4-vinylaniline and 5 mg of AIBN were weighed and added to the reaction system. The temperature was raised to 75 °C and the reaction was carried out for 9 h. After the reaction was completed, the reaction solution was magnetically separated, and the precipitate was washed with water and ethanol until the upper layer was clear. It was then dried in vacuum to obtain 560 mg of Fe3O4@SiO2@KH570-AS. (3) The obtained Fe3O4@SiO2@KH570-AS was dispersed in a mixed solvent of 150 mL of ethanol and water (3:1, v / v), placed in a 250 mL three-necked flask, and stirred in an ice bath for 0.5 h. Subsequently, 1 mol / L HCl solution was added dropwise until the pH of the reaction solution reached 3~4. After the addition was complete, the reaction was stirred in an ice bath for 0.5 h. Then, 4.62 mmoL (318 mg) of NaNO2 was weighed and dissolved in 10 mL of water. The above NaNO2 aqueous solution was slowly added dropwise to the reaction system. During the addition, 1 mol / L HCl solution was appropriately added to control the pH of the reaction system to 3~4. After the addition of the NaNO2 aqueous solution was completed, 2.1 mmoL (357 mg) of gallic acid was weighed and dissolved in 20 mL of 0.5 mol / L NaOH solution was slowly added dropwise to the reaction system. After the addition was completed, the pH was adjusted to 8-9 and the azo reaction was carried out in an ice-water bath. After the reaction had lasted for 12 h, the reaction solution was subjected to magnetic separation and the magnetic precipitate was washed with ethanol and water until neutral. The solid product was freeze-dried to obtain MPOP.

[0033] Example 2 This example studies the optimal reaction ratio of Fe3O4@SiO2@KH570 and 4-vinylaniline when synthesizing Fe3O4@SiO2@KH570-AS magnetic spheres. The steps are as follows: The amount of Fe3O4@SiO2@KH570 was controlled constant (refer to Example 1), and the amount of 4-vinylaniline was changed to 2.1 mmol / L, 4.19 mmol / L, and 8.38 mmol / L, while keeping other conditions consistent. In this way, three types of Fe3O4@SiO2@KH570-AS were prepared.

[0034] Statistical results show that when the amount of Fe3O4@SiO2@KH570 is constant, based on the 450 mg feed in Example 1, the amount of 4-vinylaniline is crucial for the introduction of aniline groups into the final product. Excessive additions can lead to self-polymerization of the vinylaniline, reducing the number of aniline groups covalently modified on the magnetic spheres. Lower amounts prevent sufficient polymerization between the vinyl groups on the Fe3O4@SiO2@KH570 magnetic spheres and the vinylaniline. Optimization revealed that when the mass of the Fe3O4@SiO2@KH570 magnetic spheres is comparable to that of the vinylaniline, as in Example 1, the Fe3O4@SiO2@KH570-AS magnetic spheres have the most covalently introduced aniline groups. This results in the highest gallic acid content during the subsequent MPOP synthesis, which is modified via azo reactions, and results in the highest adsorption capacity.

[0035] Based on this, in order to improve the adsorption effect of MPOP and reduce the loss of raw materials, when synthesizing Fe3O4@SiO2@KH570-AS, in subsequent examples, the mass ratio of Fe3O4@SiO2@KH570 and vinylaniline was controlled to be 1:1.

[0036] Example 3 This case study investigated the optimal reaction ratio of Fe3O4@SiO2@KH570-AS and gallic acid in the synthesis of MPOP. The steps are as follows: The amount of 4-vinylaniline in Example 2 was maintained at 4.19 mmol / L, and the Fe3O4@SiO2@KH570-AS magnetic spheres were synthesized under optimal conditions. The amount of gallic acid was adjusted to 2.1 mmol / L, 3.35 mmol, and 4.19 mmol / L, respectively. Other conditions remained consistent with Example 1. The yield of the obtained solid product was weighed and calculated, and the magnetic properties of different products were compared.

[0037] When the amount of gallic acid was 2.1 mmol, 3.35 mmol, and 4.19 mmol, the synthesized MPOP magnetic spheres had magnetic properties. However, as the amount of gallic acid added increased, the yield of the solid product decreased. Moreover, the more gallic acid was added, the darker the color of the reaction supernatant. This indicates that when the vinylaniline sites on the material were certain, the amount of gallic acid modified by the azo reaction was certain. When the maximum amount of modified gallic acid was exceeded, the excess gallic acid dissolved in the solution, causing the solution color to deepen. When the molar ratio of 4-vinylaniline to gallic acid was 2:1, the adsorption effect of the MPOP synthesized in Example 1 was optimal.

[0038] Based on this, in order to improve the adsorption effect of MPOP, introduce more adsorption sites and reduce raw material loss, the molar ratio of 4-vinylaniline and gallic acid was 2:1.

[0039] Example 4 This example studies the infrared spectra of Fe3O4@SiO2@KH570, Fe3O4@SiO2@KH570-As and MPOP magnetic porous materials, the pore size distribution, specific surface area and XRD of the magnetic adsorption material MPOP.

[0040] like Figure 2 As shown, Fe3O4@SiO2@KH570 has Si-O (1087 cm -1 )、Fe-O(575 cm -1 ), OH (3400cm -1 )、C=C(1600 cm -1 ) stretching vibration characteristic absorption peak, indicating that Fe3O4@SiO2@KH570 has been successfully prepared. The infrared spectrum of Fe3O4@SiO2@KH570-As has CH on the benzene ring (~2900 cm -1 )、CN(1100~1300 cm -1 ), NH (3000~3100 cm -1 ) stretching vibration peak. This indicates that Fe3O4@SiO2@KH570-As was successfully prepared. The infrared spectrum of MPOP has -N=N (~1450 cm -1 ) and CO on gallic acid (1000~1200 cm -1 ) and C=O (1700 cm -1 ), indicating that the MPOP porous material was successfully prepared.

[0041] like Figure 3 As shown in (a), the pore size of MPOP is mainly concentrated in a smaller range, with an average pore size of 7.2496 nm, indicating that the material has a relatively uniform mesoporous structure. Figure 3 (b) shows the adsorption and desorption behavior of MPOP at different relative pressures. The analysis results show that the specific surface area of MPOP is 228.94 m 2 / g.

[0042] Figure 4 The powder diffraction patterns of Fe3O4@SiO2@KH570 and MPOP are shown. There are 6 characteristic diffraction peaks with almost the same diffraction angles for Fe3O4@SiO2@KH570 and MPOP, which appear at 2 θ The characteristic peaks are located at 30.3°, 35.44°, 43.24°, 53.28°, 57.1° and 62.76°. These characteristic peaks are characteristic diffraction peaks of Fe3O4, indicating that the core structure of magnetic Fe3O4 has not changed during the synthesis of MPOP.

[0043] from Figure 5 The transmission electron microscopy images show the nanoscale particle structure and porous characteristics of the MPOP material, and the size is consistent with the pore size distribution. The above experimental results further demonstrate that the preparation of MPOP magnetic materials is successful.

[0044] Example 5 This example also studies the adsorption of organic dye methylene blue and fluoride ions by the magnetic porous material MPOP in Example 1, and explores the adsorption of MB and F by MPOP under different pH conditions. - adsorption effect.

[0045] The results are as follows Figure 6 As shown in (a), with the increase of pH, MPOP has a great influence on the - The adsorption effect is reduced mainly because under acidic conditions, the surface phenolic hydroxyl groups are protonated (-OH2 + ) and F - Through hydrogen bonding and coordination, as the pH increases, the phenolic hydroxyl group on the gallic acid deprotonates to form oxygen anions and reacts with F - Electrostatic repulsion is generated, while under alkaline conditions, the oxygen anions on the gallic acid can electrostatically attract and π-π stacking with MB to produce adsorption. Therefore, under acidic conditions, the adsorption capacity of MPOP for fluoride ions is enhanced, and under alkaline conditions, the adsorption capacity for MB is enhanced. Further research found that fluoride ions can be desorbed in a 0.1 M NaOH / ethanol mixed solution, and dyes can be desorbed in a 0.1 M HCl / ethanol solution, thereby achieving material recycling. At the same time, the desorption time after MPOP adsorption was investigated, and the results are as follows: Figure 6 As shown in (b), it can be seen from the figure that when the MPOP pH is greater than 10, about 90% of the F in the material can be resolved in 8 minutes. - MPOP can decompose about 90% of MB in 8 min under acidic conditions of pH 3.

[0046] Then the effect of adsorption time on the adsorption of fluoride ions and MB by MPOP was investigated. Ion chromatography and UV spectrophotometer were used to determine the F - The concentration of MB and the concentration of pollutants before and after adsorption, the volume of the solution, and the mass of the MPOP magnetic material can be used to calculate the adsorption capacity Q of MPOP for different pollutants at different times t, and draw an adsorption capacity Qt graph. Figure 7 As shown in the figure, it can be seen that MPOP can effectively inhibit the growth of F at pH 6 in about 30 minutes. - The results show that the prepared MPOP has fast adsorption kinetics and high adsorption capacity for fluoride ions and organic pollutants MB, and is an adsorbent with great application potential. It can be used for F- , and organic pollutants MB are removed simultaneously.

[0047] In summary, the present invention utilizes a process for preparing a magnetic porous organic polymer material, including KH570 interface modification, vinylaniline polymerization to construct a porous network, and covalent grafting with gallic acid. This process offers the advantages of a convenient process, a wide range of raw material sources, and suitability for scale-up production. The resulting magnetic porous organic polymer material exhibits a wide application threshold, exhibits excellent adsorption properties for fluoride ions and organic dyes, and enables selective desorption, resulting in excellent cost-effectiveness and reproducibility.

[0048] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for preparing a magnetic porous organic polymer material, characterized in that: The steps include: (1) Fe3O4@SiO2 magnetic spheres were dispersed in an alcohol-water solution, KH570 and ammonia were added to adjust the pH to alkaline and react, and the product was recovered and purified to obtain Fe3O4@SiO2@KH570; (2) The obtained Fe3O4@SiO2@KH570 was dispersed in N,N-dimethylformamide, 4-vinylaniline and azobisisobutyronitrile were added, and polymerization reaction was carried out under an inert atmosphere. The product was recovered and purified to obtain Fe3O4@SiO2@KH570-AS; (3) The obtained Fe3O4@SiO2@KH570-AS was dispersed in an alcohol-water solution, and hydrochloric acid was added to adjust the pH to acidic under ice bath conditions, followed by addition of sodium nitrite solution and reaction; gallic acid was then added to adjust the pH to a certain range, and the reaction was carried out in an ice bath. The product was recovered and purified to obtain a magnetic porous organic polymer material.

2. The method for preparing a magnetic porous organic polymer material according to claim 1, characterized in that: In the step (1), the preparation method of Fe3O4@SiO2 magnetic spheres is as follows: dissolving FeCl3·6H2O and FeCl2·4H2O in an alcohol aqueous solution, adding ammonia water and carrying out a hydrothermal reaction under an inert atmosphere, recovering and purifying the product to obtain Fe3O4 magnetic spheres; dispersing them in an alcohol aqueous solution, adding tetraethoxysilane and ammonia water to carry out a hydrolysis condensation reaction, recovering and purifying the product to obtain Fe3O4@SiO2 magnetic spheres.

3. The method for preparing a magnetic porous organic polymer material according to claim 2, wherein: In the hydrothermal reaction, the amount of FeCl3·6H2O added is 13~27 g, and the molar ratio of FeCl3·6H2O to FeCl2·4H2O is 2:1; the alcohol aqueous solution is a mixture of ethanol and water with a volume ratio of 2~4:1, and the amount of the alcohol aqueous solution added is 100~200 mL; the concentration of ammonia water is 28 wt.%, and the amount of the ammonia water added is 4~10 mL; in the hydrolysis condensation reaction, the amount of tetraethoxysilane added is 0.5~2 mL; the concentration of ammonia water is 28 wt.%, and the amount of the ammonia water added is 1~4 mL; the temperature of the hydrothermal reaction is 60~85°C, and the reaction time is 0.5~2 h; the temperature of the hydrolysis condensation reaction is room temperature, and the reaction time is 6~12 h.

4. The method for preparing a magnetic porous organic polymer material according to claim 1, wherein: In the step (1), the alcohol-water solution is a mixture of ethanol and water in a volume ratio of 2 to 5:1; the amount of KH570 added is 10 wt.% to 20 wt.% of the Fe3O4@SiO2 magnetic spheres; ammonia water is added to adjust the pH to 9 to 10; the reaction temperature is 25 to 45°C, and the reaction time is 6 to 12 h.

5. The method for preparing a magnetic porous organic polymer material according to claim 1, wherein: In the step (2), the mass ratio of 4-vinylaniline to Fe3O4@SiO2@KH570 is 2:1; the amount of azobisisobutyronitrile added is 0.5 wt.%~2 wt.% of 4-vinylaniline; the polymerization temperature is 65~90°C, and the reaction time is 6~12 h.

6. The method for preparing a magnetic porous organic polymer material according to claim 1, wherein: In the step (3), the alcohol-water solution is a mixture of ethanol and water in a volume ratio of 1 to 3:1; hydrochloric acid is added to adjust the pH to 3 to 4; the reaction time is 0.5 to 2 h; the molar ratio of sodium nitrite to Fe3O4@SiO2@KH570-AS in the sodium nitrite solution is 1 to 1.5:1; the mass ratio of gallic acid to Fe3O4@SiO2@KH570-AS is 1:1.5 to 2.5; the pH is adjusted to 8 to 9 by sodium hydroxide; and the ice bath reaction time is 6 to 12 h.

7. A magnetic porous organic polymer material, characterized in that: The method is as described in any one of claims 1 to 6.

8. Use of the magnetic porous organic polymer material according to claim 7, characterized in that: As a functional material, it is used to adsorb fluoride ions and organic dyes.

9. The use of the magnetic porous organic polymer material according to claim 8, characterized in that: The magnetic porous organic polymer material is used for adsorbing fluoride ions in an environment of pH=3-6, and is used for adsorbing cationic organic dyes in an environment of pH=7-11.

10. The use of the magnetic porous organic polymer material according to claim 9, characterized in that: After adsorption, depending on the type of pollutant, sodium hydroxide ethanol solution is used to desorb fluoride ions and recover the magnetic porous organic polymer material, and hydrochloric acid ethanol solution is used to desorb cationic organic dyes and recover the magnetic porous organic polymer material.

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