A deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material, preparation method and application

Abstract

The present invention belongs to the field of synthesis technology and application of macromolecular polymer materials, and discloses a deep eutectic solvent modified polyaniline@Fe3O4 nano-microsphere adsorption material, a preparation method and application. The preparation method mainly comprises the following steps: (1) preparing deep eutectic solvents (DES) ChCl-Lac, ChCl-Eg, and ChCl-Gla; (2) adding ferrous sulfate heptahydrate, ferric chloride hexahydrate, and aniline to an ammonia solution, mixing and dissolving them, and forming polyaniline@Fe3O4 (PANI@Fe3O4) in a nitrogen atmosphere; (3) using DES to modify the polyaniline@Fe3O4 to obtain ChCl-Lac-PANI@Fe3O4, ChCl-Eg-PANI@Fe3O4, and ChCl-Gla-PANI@Fe3O4; and (4) post-processing: washing with distilled water and then centrifuging, drying the precipitate, purifying, and grinding to obtain a black powder, which is the deep eutectic solvent modified polyaniline@Fe3O4 nano-microsphere adsorption material. The invention has simple preparation and low production cost; the prepared deep eutectic solvent-modified polyaniline@Fe3O4 nanoparticles can quickly adsorb and separate organic dyes, have high adsorption capacity and good circulation effect.

Description

Technical Field

[0001] The present invention belongs to the field of synthesis technology of macromolecular polymer materials and their application, and specifically relates to a deep eutectic solvent modified polyaniline@Fe3O4 nano-microsphere adsorption material, a preparation method and an application thereof. Background Art

[0002] Wastewater has attracted considerable attention due to the bioaccumulative and persistent nature of pollutants. Brightly colored organic dyes are chemically stable, difficult to biodegrade, and toxic to aquatic organisms and humans throughout their life cycle. Therefore, there is an urgent need to remove both cationic and anionic organic dye pollutants.

[0003] The adsorption method has broad application prospects due to its advantages such as simple operation, high removal efficiency, low energy consumption and large application scale. Adsorption technology is more beneficial to the environment and human health because the adsorption method generally uses low-cost, relatively simple and harmless materials. The basic principle of the adsorption method is to use the affinity of the adsorbent itself to separate the target substance from the mixture. The properties of the substance do not change during the separation process, so it can be operated at room temperature, providing an excellent energy-saving measure. Common adsorbents mainly include: hyperbranched polyamide cellulose, multilayer graphene nanosheets, carbon composite lignin-based adsorbents, covalent triazine skeletons, porous polyionic liquid adsorbents, etc. However, the preparation of some of the above-mentioned adsorbents is relatively expensive, some adsorbents are highly dispersible, and are difficult to recover, which can easily cause secondary pollution.

[0004] Macromolecular polymers have stable physical and chemical properties, are simple to prepare, and more importantly, some of them show very good recycling value. Micro-nano macromolecular polymer microspheres have advantages such as rich pore structure, large specific surface area, high thermal stability, and excellent mechanics. In addition, micro-nano macromolecular polymer microspheres are easy to recycle and reuse. Micro-nano macromolecular polymer microspheres with active sites such as oxygen and nitrogen have excellent adsorption effects on dyes. Studies have shown that micro-nano macromolecular polymer microspheres modified with deep eutectic solvents greatly improve the adsorption performance of dyes and can achieve adsorption of different organic dyes. Based on this, the present invention proposes a preparation method to prepare deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres, and apply them to the field of dye adsorption. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a synthesis method of deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres and their application in the field of adsorption. A simple and low-cost preparation method is used to prepare a micro-nano macromolecular polymer microsphere with high specific surface area, rich pore size and large adsorption capacity. It is used in the field of dye adsorption and has excellent adsorption effect on methyl orange or methylene blue in wastewater.

[0006] In order to achieve the purpose of the present invention, the synthesis method of deep eutectic solvent modified polyaniline@Fe3O4 nanospheres of the present invention comprises the following steps:

[0007] (1) Preparation of deep eutectic solvent (DES): Choline chloride was fully mixed with lactic acid, diethanol, and glycolic acid, respectively, and heated for reaction. The colorless liquid was collected by filtration, rotary evaporated, and finally vacuum dried to obtain a colorless transparent liquid. Three deep eutectic solvents were obtained and labeled as ChCl-Lac, ChCl-Eg, and ChCl-Gla respectively;

[0008] (2) adding ferrous sulfate heptahydrate, ferric chloride hexahydrate, and aniline into an ammonia solution, mixing and dissolving them, and fully reacting them in a nitrogen atmosphere to form polyaniline@Fe3O4;

[0009] (3) dissolving the DES obtained in step (1) in a methanol solution, and then adding the polyaniline@Fe3O4 nanospheres obtained in step (2) to obtain nanospheres after sufficient reaction;

[0010] (4) The nanospheres obtained in step (3) were post-treated by washing with distilled water several times, centrifuging, removing the supernatant, collecting the precipitate, fully drying the precipitate, and finally grinding to obtain a black solid powder, which is the deep eutectic solvent modified polyaniline@Fe3O4 nanospheres, respectively denoted as ChCl-Lac-PANI@Fe3O4, ChCl-Eg-PANI@Fe3O4, and ChCl-Gla-PANI@Fe3O4;

[0011] Furthermore, in some embodiments of the present invention, in step (1), the molar ratio of choline chloride to lactic acid is 0.01-0.03:0.03-0.05; the molar ratio of choline chloride to ethylene glycol is 0.02-0.03:0.03-0.06; and the molar ratio of choline chloride to glycolic acid is 0.02-0.04:0.03-0.08.

[0012] Preferably, in some embodiments of the present invention, the molar volume ratio of the ferrous sulfate heptahydrate, ferric chloride hexahydrate, aniline and ammonia water is 0.03-0.05 mol: 0.02-0.04 mol: 0.2-0.6 ml: 6-12 ml.

[0013] Furthermore, in some embodiments of the present invention, the heating reaction in step (1) is heated at 50-80° C. for 3-6 hours.

[0014] Furthermore, in some embodiments of the present invention, the rotary evaporation in step (1) is performed at 60° C. for 1-2 h.

[0015] Furthermore, in some embodiments of the present invention, the ratio of ferrous sulfate heptahydrate to ferric chloride hexahydrate in step (2) is 0.70-1.50 g:1-2 g.

[0016] Furthermore, in some embodiments of the present invention, the molar ratio of ferric chloride hexahydrate to aniline in step (2) is 0.0025-0.0055:0.0005-0.001.

[0017] Furthermore, in some embodiments of the present invention, the molar ratio of aniline to ammonia water in step (2) is 0.0018-0.003:0.003-0.055.

[0018] Furthermore, in some embodiments of the present invention, the ratio of aniline to ammonia water in step (2) is 0.2-0.6 ml:6-12 ml.

[0019] Furthermore, in some embodiments of the present invention, the sufficient reaction in the nitrogen atmosphere in step (2) is first reacted at 30-40° C. for 30-60 min, and then heated to 70-85° C. for 22-30 h.

[0020] Furthermore, in some embodiments of the present invention, in step (3), the molar volume ratio of ChCl-Lac, ChCl-Eg, ChCl-Gla and methanol is 0.01-0.03 mol: 0.02-0.03 mol: 0.02-0.03 mol: 30-50 ml.

[0021] Furthermore, in some embodiments of the present invention, in step (3), the molar ratio of ChCl-Lac, ChCl-Eg, ChCl-Gla and polyaniline@Fe3O4 is 0.01-0.03:0.03-0.05:0.02-0.03:0.0025-0.0035.

[0022] Furthermore, in some embodiments of the present invention, the centrifugation of distilled water in step (4) is performed at 5000-8000 r / min, and the number of centrifugation times is 5-10 times.

[0023] Furthermore, in some embodiments of the present invention, the drying in steps (1) and (4) is performed at 65-100° C. for 18-24 hours.

[0024] The present invention protects a deep eutectic solvent modified polyaniline@Fe3O4 nano-microsphere, wherein the deep eutectic solvent modified polyaniline@Fe3O4 nano-microsphere is prepared by the above-mentioned preparation method.

[0025] The present invention further protects the use of the deep eutectic solvent-modified polyaniline@Fe3O4 nanoparticles prepared by the above preparation method in the adsorption of organic dyes, wherein the application is for adsorbing methyl orange or methylene blue in wastewater.

[0026] The preparation method provided by the present invention utilizes chemical deposition and oxidation reaction principles to prepare deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres with a large specific surface area and rich active sites such as oxygen and nitrogen. The adsorbed methyl orange and methylene blue have highly electronegative atomic groups. Therefore, the deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres exhibit strong adsorption capacity for methyl orange or methylene blue. Furthermore, the deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres are easy to recycle and have good recyclability (after six cycles of adsorption-desorption, the adsorption effect still remains between 86-90%).

[0027] The advantages of the present invention are as follows:

[0028] (1) The process of the present invention is simple to synthesize and low in cost. The prepared deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres have rich pores and pore sizes. The same material can achieve good adsorption effects on different dyes with extremely high adsorption efficiency.

[0029] (2) The present invention uses Fe3O4 as a core-shell structure, providing a foundation for subsequent recycling. The introduction of a deep eutectic solvent reduces the electron cloud density of the benzene ring on the original polyaniline@Fe3O4, increasing its activity and the number of active sites. This greatly improves the adsorption capacity for methyl orange or methylene blue, resulting in high removal efficiency and significant separation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 FTIR graph of the deep eutectic solvent obtained in an embodiment of the present invention;

[0031] Figure 2 FTIR image of deep eutectic solvent modified polyaniline@Fe3O4 nanospheres obtained in an embodiment of the present invention;

[0032] Figure 3 This is the XRD pattern of deep eutectic solvent modified polyaniline@Fe3O4 nanospheres prepared in an embodiment of the present invention;

[0033] Figure 4 This is a diagram showing the adsorption of dyes of different concentrations by deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres prepared in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through practice of the present invention. It should be understood that the following description is only intended to explain the present invention and is not intended to limit the present invention.

[0035] As used herein, the terms "comprises," "including," "having," "containing" or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a listed element is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0036] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range limited by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0037] The indefinite article "a" before an element or component of the present invention does not limit the quantity requirement (i.e., the number of occurrences) of the element or component. Therefore, "a" or "an" should be interpreted as including one or at least one, and an element or component in the singular also includes the plural form, unless the quantity clearly refers to only the singular form.

[0038] In addition, the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" described below mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the technical features involved in the various embodiments of the present invention may be combined with each other as long as they do not conflict with each other.

[0039] Example 1

[0040] The synthesis of deep eutectic solvent modified polyaniline@Fe3O4 nanospheres represented by choline chloride and lactic acid (i.e., adding choline chloride and lactic acid in step (3)).

[0041] (1) Preparation of deep eutectic solvent: 2.79 g of choline chloride and 1.80 g of lactic acid were thoroughly mixed together and heated at 80 °C for 5 h. The colorless liquid was collected by filtration, rotary evaporated at 60 °C for 1 h, and finally dried in a vacuum drying oven at 80 °C for 24 h. The product was collected and recorded as ChCl-Lac.

[0042] (2) Dissolve 5.56 g of ferrous sulfate heptahydrate in 10 ml of ammonia solution, mix thoroughly, and then add 5.41 g of ferric chloride hexahydrate. Allow the mixture to react fully under a nitrogen atmosphere. Initially heat at 30°C for 30 min, then raise the temperature to 70°C and react for 22 h to obtain polyaniline@Fe3O4.

[0043] (3) 4.59 g of ChCl-Lac obtained in step (1) was dissolved in 30 ml of methanol solution, and then 0.35 g of polyaniline@Fe3O4 nanospheres obtained in step (2) were added. After sufficient reaction, magnetic nanospheres were obtained, which were recorded as ChCl-Lac-PANI@Fe3O4.

[0044] (4) The magnetic nanospheres obtained in step (3) are post-treated; first, deionized water is used for centrifugation at 5000 r / min for 5 minutes, and a total of 8 centrifugations are performed. After centrifugation, the supernatant is removed and the precipitate is collected. The precipitate is dried in a vacuum drying oven at 80° C. for 20 hours, and finally ground to obtain black solid powder particles, which are the polyaniline@Fe3O4 nanospheres modified with the deep eutectic solvent represented by ChCl-Lac of the present invention.

[0045] Example 2

[0046] The synthesis of polyaniline@Fe3O4 nanospheres modified with deep eutectic solvents represented by choline chloride and ethylene glycol (i.e., adding choline chloride and ethylene glycol in step (3)).

[0047] (1) Preparation of deep eutectic solvent: 2.79 g of choline chloride and 1.86 g of ethylene glycol were thoroughly mixed and heated at 80 °C for 5 h. The colorless liquid was collected by filtration, rotary evaporated at 60 °C for 1 h, and finally dried in a vacuum oven at 80 °C for 24 h. The product was collected and recorded as ChCl-Eg.

[0048] (2) Dissolve 5.56 g of ferrous sulfate heptahydrate in 10 ml of ammonia solution, mix thoroughly, and then add 5.41 g of ferric chloride hexahydrate. Allow the mixture to react fully under a nitrogen atmosphere. Initially heat at 30°C for 30 min, then raise the temperature to 70°C and react for 22 h to obtain polyaniline@Fe3O4.

[0049] (3) 6.05 g of ChCl-Eg obtained in step (1) was dissolved in 30 ml of methanol solution, and then 0.36 g of polyaniline@Fe3O4 nanospheres obtained in step (2) were added. After sufficient reaction, magnetic nanospheres were obtained, which were recorded as ChCl-Eg-PANI@Fe3O4.

[0050] (4) The magnetic nanospheres obtained in step (3) are post-treated; first, deionized water is used for centrifugation at 5000 r / min for 5 minutes, and a total of 8 centrifugations are performed. After centrifugation, the supernatant is removed and the precipitate is collected. The precipitate is dried in a vacuum drying oven at 80° C. for 20 hours, and finally ground to obtain black solid powder particles, which are the polyaniline@Fe3O4 nanospheres modified with a deep eutectic solvent represented by ChCl-Eg of the present invention.

[0051] Example 3

[0052] The synthesis of deep eutectic solvent modified polyaniline@Fe3O4 nanospheres represented by choline chloride and glycolic acid (i.e., adding choline chloride and glycolic acid in step (3)).

[0053] (1) Preparation of deep eutectic solvent: 2.79 g of choline chloride and 1.52 g of glycolic acid were thoroughly mixed together and heated at 80 °C for 5 h. The colorless liquid was collected by filtration, rotary evaporated at 60 °C for 1 h, and finally dried in a vacuum oven at 80 °C for 24 h. The product was collected and recorded as ChCl-Gla.

[0054] (2) Dissolve 5.56 g of ferrous sulfate heptahydrate in 10 ml of ammonia solution, mix thoroughly, and then add 5.41 g of ferric chloride hexahydrate. Allow the mixture to react fully under a nitrogen atmosphere. Initially heat at 30°C for 30 min, then raise the temperature to 70°C and react for 22 h to obtain polyaniline@Fe3O4.

[0055] (3) 4.31 g of ChCl-Gla obtained in step (1) was dissolved in 30 ml of methanol solution, and then 0.38 g of polyaniline@Fe3O4 nanospheres obtained in step (2) were added. After sufficient reaction, magnetic nanospheres were obtained, which were recorded as ChCl-Gla-PANI@Fe3O4.

[0056] (4) The magnetic nanospheres obtained in step (3) are post-treated; first, deionized water is used for centrifugation at 5000 r / min for 5 minutes, and a total of 8 centrifugations are performed. After centrifugation, the supernatant is removed, and the precipitate is collected. The precipitate is dried in a vacuum drying oven at 80° C. for 20 hours, and finally ground to obtain black solid powder particles, which are the polyaniline@Fe3O4 nanospheres modified with the deep eutectic solvent represented by ChCl-Eg of the present invention.

[0057] Test Example 1

[0058] The deep eutectic solvents synthesized in Examples 1-3 were characterized by FTIR to prove the successful preparation of the deep eutectic solvents. The FTIR spectra of three different deep eutectic solvents (ChCl-Lac, ChCl-Eg, ChCl-Gla) are as follows: Figure 1 shown.

[0059] Test Example 2

[0060] The deep eutectic solvent modified polyaniline@Fe3O4 nanospheres prepared in Examples 1-3 were characterized by FTIR to prove the successful preparation of deep eutectic solvents. The FTIR spectra of three different deep eutectic solvent modified polyaniline@Fe3O4 nanospheres (ChCl-Lac-PANI@Fe3O4, ChCl-Eg-PANI@Fe3O4, ChCl-Eg-PANI@Fe3O4) were as follows: Figure 2 shown.

[0061] Methyl orange was used in adsorption experiments to test the adsorption performance of the adsorbents prepared in Examples 1-3. Using 50 ml of a 50 mg / L methyl orange solution as the adsorbate, 0.02 g of each adsorbent was used. Adsorption was performed at 25°C. The adsorption data for polyaniline@Fe₃O₄ nanospheres modified with different deep eutectic solvents are shown in Table 1.

[0062] Table 1 Adsorption data of methyl orange on the deep eutectic solvent modified polyaniline@Fe3O4 nanospheres of Examples 1-3.

[0063] adsorbent Adsorption conditions Adsorption capacity Removal efficiency <![CDATA[PANI@Fe3O4]]> 0.02g, 50ml, 25℃, 1300min 98.25mg / g 78.6％ <![CDATA[ChCl-Lac-PANI@Fe3O4]]> 0.02g, 50ml, 25℃, 1300min 124.75mg / g 99.8％ <![CDATA[ChCl-Gla-PANI@Fe3O4]]> 0.02g, 50ml, 25℃, 1300min 122.00mg / g 97.6％ <![CDATA[ChCl-Eg-PANI@Fe3O4]]> 0.02g, 50ml, 25℃, 1300min 122.75mg / g 98.2％

[0064] The data in the table shows that ChCl-Lac-PANI@Fe3O4 exhibits the best adsorption efficiency for methyl orange, reaching equilibrium within 10 minutes. The adsorption capacity reaches 124.75 mg / g, and the removal efficiency reaches 99.8%. The table also demonstrates the crucial role of the deep eutectic solvent in adsorption. Compared to polyaniline@Fe3O4 (PANI@Fe3O4), the successful introduction of the deep eutectic solvent significantly improves adsorption capacity, removal efficiency, and adsorption rate.

[0065] Test Example 3

[0066] The nanospheres prepared in Examples 1-3 were subjected to adsorption tests at different concentrations. Figure 4 As shown in (A), the deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres prepared in an embodiment of the present invention adsorb methyl orange solutions of different concentrations. It can be found that ChCl-Lac-PANI@Fe3O4 has the best adsorption effect on methyl orange, with the highest adsorption capacity reaching 912.71 mg / g.

[0067] Test Example 4

[0068] Methylene blue was used in adsorption experiments to test the adsorption performance of the adsorbents prepared in Examples 1-3. Using a 50 ppm methylene blue solution as the adsorbate, 50 ml of the solution was used, along with 0.03 g of each adsorbent. Adsorption was performed at 25°C. The adsorption data for polyaniline@Fe₃O₄ nanospheres modified with different deep eutectic solvents are shown in Table 2.

[0069] Table 2 Adsorption data of methyl blue by the deep eutectic solvent modified polyaniline@Fe3O4 nanospheres of Examples 1-3.

[0070] adsorbent Adsorption conditions Adsorption capacity Removal efficiency <![CDATA[PANI@Fe3O4]]> 0.03g, 50ml, 25℃, 1300min 58.63mg / g 70.36％ <![CDATA[ChCl-Lac-PANI@Fe3O4]]> 0.03g, 50ml, 25℃, 1300min 79.83mg / g 95.8％ <![CDATA[ChCl-Gla-PANI@Fe3O4]]> 0.03g, 50ml, 25℃, 1300min 76.33mg / g 91.6％ <![CDATA[ChCl-Eg-PANI@Fe3O4]]> 0.03g, 50ml, 25℃, 1300min 76.83mg / g 92.2％

[0071] The data in the table shows that ChCl-Lac-PANI@Fe3O4 exhibits the best adsorption efficiency for methylene blue, reaching equilibrium in approximately 12 minutes. The adsorption capacity reaches 79.83 mg / g, and the removal efficiency reaches 95.8%. The table also demonstrates the crucial role of the deep eutectic solvent in adsorption. Compared to polyaniline@Fe3O4 (PANI@Fe3O4), the successful introduction of the deep eutectic solvent significantly improves adsorption capacity, removal efficiency, and adsorption rate.

[0072] Test Example 5

[0073] The prepared nanospheres of Examples 1-3 were subjected to adsorption tests at different concentrations. Figure 4 (B) shows the effect of deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres prepared in an embodiment of the present invention on the adsorption of methylene blue solutions of different concentrations. It can be found that ChCl-Lac-PANI@Fe3O4 has the best adsorption effect on methylene blue, with the highest adsorption capacity reaching 473.95 mg / g.

[0074] The above experiments demonstrate that the deep eutectic solvent-modified polyaniline@Fe₃O₄ nanospheres obtained in this invention exhibit excellent dye adsorption, selectively separating both cationic and anionic dyes from wastewater. In contrast, the polyaniline@Fe₃O₄ nanospheres prepared in Comparative Example 1 exhibited less pronounced adsorption, were unable to efficiently remove dye components, and were therefore limited in their usability.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, and modifications made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material, characterized in that: The following steps are involved: (1) Preparation of deep eutectic solvent DES: Choline chloride was fully mixed with lactic acid, diethanol, and glycolic acid, respectively, and heated for reaction. The colorless liquid was collected by filtration, rotary evaporated, and finally vacuum dried to obtain a colorless transparent liquid. Three deep eutectic solvents were obtained and labeled as ChCl-Lac, ChCl-Eg, and ChCl-Gla respectively; (2) adding ferrous sulfate heptahydrate, ferric chloride hexahydrate, and aniline to an ammonia solution, mixing and dissolving them, and fully reacting them in a nitrogen atmosphere to form polyaniline@Fe3O4, i.e., PANI@Fe3O4; the molar volume ratio of the ferrous sulfate heptahydrate, ferric chloride hexahydrate, aniline, and ammonia solution is 0.03-0.05 mol: 0.02-0.04 mol: 0.2-0.6 ml: 6-12 ml; the molar ratio of ferric chloride hexahydrate to aniline is 0.0025-0.0055: 0.0005-0.001; and the molar ratio of aniline to ammonia solution is 0.0018-0.003: 0.003-0.055; In step (2), the reaction is carried out in a nitrogen atmosphere by first reacting at 30-40°C for 30-60 minutes, and then heating to 70-85°C for 22-30 hours; (3) The DES obtained in step (1) was dissolved in a methanol solution, and then the polyaniline@Fe3O4 nanospheres obtained in step (2) were added, and the nanospheres were obtained after sufficient reaction, which were respectively recorded as ChCl-Lac-PANI@Fe3O4, ChCl-Eg-PANI@Fe3O4, and ChCl-Gla-PANI@Fe3O4; The molar ratio of ChCl-Lac, ChCl-Eg, ChCl-Gla and polyaniline@Fe3O4 is 0.01-0.03:0.03-0.05:0.02-0.03:0.0025-0.003; (4) The nanospheres obtained in step (3) are post-treated by first washing with distilled water, centrifuging, removing the supernatant, collecting the precipitate, fully drying the precipitate, and finally grinding to obtain a black solid powder, which is the deep eutectic solvent-modified polyaniline@Fe3O4 nanospheres.

2. The method for preparing the deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material according to claim 1, characterized in that: In the step (1), the molar ratio of choline chloride to lactic acid is 0.01-0.03:0.03-0.05; the molar ratio of choline chloride to ethylene glycol is 0.02-0.03:0.03-0.06; and the molar ratio of choline chloride to glycolic acid is 0.02-0.04:0.03-0.

08.

3. The preparation method of the deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material according to claim 1, characterized in that: The heating reaction in step (1) is carried out at 50-80° C. for 3-6 hours.

4. The method for preparing the deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material according to claim 1, characterized in that: In the step (1), the rotary evaporation is carried out at 60° C. for 1-2 hours.

5. The method for preparing the deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material according to claim 1, characterized in that: The centrifugation in step (4) is performed at 5000-8000 r / min for 5-10 times.

6. The method for preparing the deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material according to claim 1, characterized in that: The drying in steps (1) and (4) is carried out at 65-100° C. for 18-24 hours.

7. A deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material, characterized in that: The deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material is prepared by the preparation method according to any one of claims 1-6.

8. Application of the deep eutectic solvent modified polyaniline@Fe3O4 nanosphere adsorption material prepared by the preparation method according to any one of claims 1 to 6 in the adsorption of organic dyes, characterized in that: The application is to adsorb methyl orange or methylene blue in wastewater.

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