A magnetic graphene-based composite material for dye degradation and preparation method thereof

Abstract

The present application relates to the fields of nanomaterials and environmental science and technology, and specifically discloses a magnetic graphene-based composite material for dye degradation and a preparation method thereof. The composite material comprises the following raw materials in parts by weight: 36-44 parts of functionalized graphene oxide, 6-8 parts of thiolated core-shell particles, 0.02-0.06 parts of a photoinitiator, and 320-360 parts of deionized water. The antibacterial property of the functionalized graphene oxide is reflected in the aniline structure, chitosan structure, and graphene oxide structure, the adsorption property of the functionalized graphene oxide is reflected in the improved dispersibility of the modified graphene oxide, the antibacterial property of the thiolated core-shell particles is reflected in the nanomagnetic ferrosoferric oxide structure, titanium dioxide structure, and pyrimidine ring structure, and the adsorption and degradability of the thiolated core-shell particles are reflected in the structure obtained by bonding the thiolated core-shell particles and the functionalized graphene oxide and the porous core-shell structure. Through the synergistic effect of the above structures, the antibacterial property, adsorption, and degradability of the material are improved.

Description

Technical Field

[0001] The present application relates to the field of nanomaterials and environmental science and technology, and more specifically, to a magnetic graphene-based composite material for degrading dyes and a preparation method thereof. Background Art

[0002] The rapid development of the textile printing and dyeing industry has also brought with it numerous environmental challenges, with water pollution being the most pressing issue. To ensure the sustainable development of the printing and dyeing industry, reduce threats to water resources, and protect human health, water pollution issues arising from the printing and dyeing industry must be addressed. Therefore, finding a simple and feasible new method for treating printing and dyeing wastewater is of great significance.

[0003] Methods for treating dye wastewater mainly include adsorption, biotechnology, catalytic processes, membrane technology, ionizing radiation technology, and magnetic field-assisted processes. Among them, physical adsorption based on various adsorbent materials has the advantages of easy operation, fast speed, high efficiency, and strong adaptability for treating pollutants in wastewater. In addition, this type of adsorbent is generally insoluble in water and only adsorbs pollutants on the surface of the material without undergoing further chemical reactions. Therefore, it usually does not produce new pollutants in the water body and is easy to separate. Nano-Fe3O4 is a new type of magnetic adsorption material that has attracted widespread attention due to its high adsorption capacity and selectivity and easy separation and recovery. The existing technology has successfully combined it with graphene oxide with a large specific surface area to prepare magnetic graphene-based composite materials. However, nano-Fe3O4 is prone to agglomeration, resulting in uneven dispersion on the graphene oxide surface. At the same time, during the sewage treatment process, there are microorganisms that easily invade the active adsorption sites. All of these factors will lead to reduced adsorption and degradation properties of the prepared graphene-based composite materials.

[0004] Based on the above statements, the present application provides a magnetic graphene-based composite material for degrading dyes and a preparation method thereof. Summary of the Invention

[0005] In order to solve the problem in the prior art that nano-Fe3O4 is easy to agglomerate, resulting in uneven dispersion on the surface of graphene oxide, and at the same time, during the sewage treatment process, there are microorganisms that are easy to invade active adsorption sites, resulting in a decrease in the adsorption and degradation properties of the prepared graphene-based composite material, the present application provides a magnetic graphene-based composite material for degrading dyes and a preparation method thereof.

[0006] A magnetic graphene-based composite material for dye degradation, comprising the following raw materials in parts by weight: 36-44 parts of functionalized graphene oxide, 6-8 parts of thiol-modified core-shell particles, 0.02-0.06 parts of a photoinitiator, and 320-360 parts of deionized water;

[0007] The preparation method of the magnetic graphene-based composite material for degrading dyes comprises the following steps:

[0008] Functionalized graphene oxide is ultrasonically dispersed in deionized water, heated to 60-70°C, and then thiol core-shell particles and a photoinitiator are added. The mixture is stirred evenly, irradiated with ultraviolet light for 10-20 minutes, rotary evaporated, washed, and dried to obtain a magnetic graphene-based composite material for dye degradation.

[0009] Preferably, the photoinitiator is sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate.

[0010] Preferably, the peak wavelength of the irradiation is 365nm and the intensity is 80mw / cm 2 .

[0011] Preferably, the functionalized graphene oxide is prepared by the following steps:

[0012] Step A1, add butenedioic acid to anhydrous ethanol, heat to 40-46 ° C, stir evenly, then add a mixture of N, N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol a, heat to reflux, stir and react for 4-6 hours, centrifuge after the reaction, wash the precipitate, and dry to obtain an unsaturated monomer, wherein the mass ratio of butenedioic acid, anhydrous ethanol and mixture b is 2-4:46-54:22-28, in the mixture a, N, N'-dicyclohexylcarbodiimide The mass ratio of 4-dimethylaminopyridine, aniline and anhydrous ethanol is 4-7:3-5:1.5-3.1:32. In the above reaction process, N,N'-dicyclohexylcarbodiimide is used as a dehydrating agent and 4-dimethylaminopyridine is used as an acylating agent to cause the carboxyl group on the butenedioic acid to undergo an amidation reaction with the amino group on the aniline to obtain an unsaturated monomer. During the reaction, the amount of the butenedioic acid is controlled to be slightly higher than the amount of the aniline so that after the reaction is completed, there are still remaining carboxyl groups that can participate in the subsequent reaction process;

[0013] Step A2, mixing graphene oxide and deionized water, and ultrasonically dispersing to obtain a graphene oxide suspension; at room temperature, adjusting the pH value to 8-9, and adding a mixed solution b of an unsaturated monomer and anhydrous DMF dropwise, controlling the dripping to be completed within 15 minutes, and after completion of the dripping, heating to 75-85° C. under a nitrogen atmosphere, maintaining the speed constant, stirring and reacting for 10-20 minutes, filtering, washing, and drying to obtain modified graphene oxide, wherein the mass ratio of graphene oxide to deionized water is 1:100, the mass ratio of the graphene oxide suspension to the mixed solution b is 20-30:14-16, and the mass ratio of the unsaturated monomer to anhydrous DMF in the mixed solution b is 3-5:20. During the above reaction process, the amino group on the unsaturated monomer can undergo an amidation reaction with the carboxyl group on the surface of the graphene oxide and be grafted onto the surface of the graphene oxide, thereby reducing the agglomeration of the graphene oxide, improving the dispersion performance of the graphene oxide, and improving the adsorption performance of the graphene oxide;

[0014] Step A3, chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide are added to an acetic acid aqueous solution, stirred evenly, and then the modified graphene oxide aqueous solution is added, the temperature is raised to 54-66°C, stirred for reaction for 1-2 hours, cooled to room temperature, the pH value is adjusted to neutral, filtered under reduced pressure, washed, and dried to obtain functionalized graphene oxide, wherein chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, The mass ratio of N-hydroxysuccinimide, acetic acid aqueous solution and modified graphene oxide aqueous solution is 0.6:3-4:2.6-3.0:25-35:46-52. The modified graphene oxide aqueous solution is obtained by ultrasonic dispersion of modified graphene oxide and deionized water in a mass ratio of 1:10. The mass fraction of the acetic acid aqueous solution is 0.6-1%. During the above process, the active amino groups on the chitosan undergo amidation reaction with the carboxyl groups on the modified graphene oxide to obtain functionalized graphene oxide.

[0015] Preferably, the thiol core-shell particles are prepared by the following steps:

[0016] Step B1, ultrasonically disperse nano-magnetic ferroferric oxide in anhydrous ethanol, add tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water mixed solution C, control the dripping within 10 minutes, after the dripping, adjust the pH to 2-3, heat to 44-52 ° C, keep stirring for 18-22 minutes, then heat to reflux, stir and react for 6-8 hours to obtain modified core-shell particles, wherein the mass ratio of nano-magnetic ferroferric oxide, anhydrous ethanol and mixed solution C is 2.4-3.2:50-60 : 20-26, in the mixed solution c, the mass ratio of tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water is 12-14:1:8-10:3-5. During the above reaction process, the stability of ferroferric oxide is poor. In the above step, anhydrous ethanol is used as a solvent and hexadecyltrimethylammonium bromide is used as a porogen. Porous titanium dioxide is coated on the surface of ferroferric oxide by a sol-gel method, which not only improves its oxidation resistance and stability, stabilizes its magnetic properties, but also improves its adsorption and degradation properties.

[0017] Step B2, ultrasonically mixing the modified core-shell particles, deionized water, anhydrous ethanol and KH-560 for 20-30 minutes, stirring at room temperature for 6-8 hours, centrifuging, washing and drying the precipitate to obtain epoxy core-shell particles, ultrasonically dispersing the epoxy core-shell particles and anhydrous DMF, and dropwise adding a mixture of tetrabutylammonium bromide, 2-mercaptonicotinic acid and anhydrous DMF. After the addition is completed, the mixture is heated to 105-115°C and stirred for 2-3 hours. After the reaction is completed, centrifugation is performed, and the precipitate is washed and dried to obtain thiolated core-shell particles, wherein the mass ratio of the modified core-shell particles, deionized water, anhydrous ethanol and KH-560 is 3-5. : 12:30-34:0.4-0.6, the mass ratio of epoxy core-shell particles, anhydrous DMF and mixed liquid d is 2-4:44-50:14, and the mass ratio of tetrabutylammonium bromide, 2-mercaptonicotinic acid and anhydrous DMF in the mixed liquid d is 0.2:1.2-1.6:12. In the above reaction process, the core-shell particles are first treated with KH-560, and then the carboxyl group of 2-mercaptonicotinic acid and the epoxy group undergo a ring-opening esterification reaction under the action of tetrabutylammonium bromide to obtain thiolated core-shell particles. In the above reaction, a pyridine ring with antibacterial properties and a chemically active thiol group are introduced to pave the way for subsequent reactions.

[0018] In summary, the present application has the following beneficial effects: the present invention adds functionalized graphene oxide and thiol core-shell particles in the process of preparing a magnetic graphene-based composite material for degrading dyes, wherein the functionalized graphene oxide is prepared by chemically bonding chitosan and modified graphene oxide, wherein the modified graphene oxide is first chemically bonded by butenedioic acid and aniline, and then chemically bonded with graphene oxide, and the prepared modified graphene oxide has both antibacterial properties and adsorption properties, wherein the antibacterial properties are reflected in the aniline structure, the chitosan structure and the graphene oxide structure, and the adsorption properties are reflected in the π-π interaction between the modified graphene oxide structure and the chitosan structure, so that the modified graphene oxide has good antibacterial properties. The graphene structure is adsorbed on the surface of the chitosan structure, which improves the dispersion of graphene oxide and improves the adsorption performance of the graphene-based composite material. The thiol core-shell particles are prepared by chemical combination of phenyl chitosan and pyrimidine derivatives containing thiol groups. On the one hand, antibacterial properties are exerted, and on the other hand, adsorption and degradation properties are exerted. The antibacterial properties are embodied in the nanomagnetic ferroferric oxide structure, titanium dioxide structure and pyrimidine ring structure. Adsorption and degradation properties are embodied in the three-dimensional network structure and porous core-shell structure obtained by chemical bonding of the thiol core-shell particles thiol and functionalized graphene oxide. In addition, the porous core-shell structure exists, which reduces agglomeration and further improves its adsorption and degradation properties. In summary, the present invention improves the antibacterial properties, adsorption and degradation properties of the magnetic graphene-based composite material for degrading dyes through the combined action of the above-mentioned structures. DETAILED DESCRIPTION

[0019] In order to make the implementation methods of the present application easier to understand, the present application will be described in detail below with reference to specific examples. These examples are only for illustration and are not intended to limit the scope of application of the present application.

[0020] Preparation Examples 1-3 and Comparative Preparation Examples 1-2 provide a functionalized graphene oxide.

[0021] Preparation Example 1

[0022] This preparation example provides a functionalized graphene oxide, which is prepared by the following steps:

[0023] Step A1, adding butenedioic acid to anhydrous ethanol, heating to 40°C, stirring at 450 rpm for 12 minutes until uniform, then adding a mixture a of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol, heating to reflux, maintaining the speed constant, and continuing to stir and react for 4 hours. After the reaction is completed, centrifugation is performed, and the precipitate is washed three times with anhydrous ethanol and deionized water in sequence, and dried at 50°C to constant weight to obtain an unsaturated monomer, wherein the mass ratio of butenedioic acid, anhydrous ethanol and mixture a is 2:46:22, and the mass ratio of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol in mixture a is 4:3:1.5:32;

[0024] Step A2, mixing graphene oxide and deionized water, ultrasonically treating at an ultrasonic frequency of 25 kHz and an ultrasonic power of 400 w for 16 minutes to obtain a graphene oxide suspension; at room temperature, adjusting the pH value to 8 with a 0.6 M sodium hydroxide aqueous solution, adding a mixed solution b of an unsaturated monomer and anhydrous DMF dropwise, and controlling the dripping within 15 minutes. After the dripping is completed, the temperature is raised to 75° C. under a nitrogen atmosphere, the speed is maintained constant, and the reaction is stirred for 10 minutes. Filter, wash with anhydrous ethanol and deionized water three times in sequence, and dry at 55° C. to constant weight to obtain modified graphene oxide, wherein the mass ratio of graphene oxide to deionized water is 1:100, the mass ratio of graphene oxide suspension to mixed solution b is 20:14, and the mass ratio of unsaturated monomer to anhydrous DMF in mixed solution b is 3:20;

[0025] Step A3, chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide were added to an acetic acid aqueous solution, stirred at a speed of 650 rpm for 18 minutes until uniform, then the modified graphene oxide aqueous solution was added, the temperature was raised to 54°C, the speed was maintained constant, and the stirring reaction was continued for 1 hour. The mixture was cooled to room temperature, the pH value was adjusted to neutral with a 0.6M sodium hydroxide aqueous solution, the mixture was filtered under reduced pressure, washed with deionized water three times, and dried at 55°C to constant weight to obtain functionalized graphene oxide, wherein the mass ratio of chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, acetic acid aqueous solution and modified graphene oxide aqueous solution was 0.6:3:2.6:25:46, the modified graphene oxide aqueous solution was obtained by ultrasonically dispersing the modified graphene oxide and deionized water in a mass ratio of 1:10, and the mass fraction of the acetic acid aqueous solution was 0.6%.

[0026] Preparation Example 2

[0027] This preparation example provides a functionalized graphene oxide, which is prepared by the following steps:

[0028] Step A1, adding butenedioic acid to anhydrous ethanol, heating to 43°C, stirring at 500 rpm for 8 minutes until uniform, then adding a mixture a of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol, heating to reflux, maintaining the speed constant, stirring and reacting for 5 hours. After the reaction, centrifugation is performed, and the precipitate is washed four times with anhydrous ethanol and deionized water in sequence, and dried at 55°C to constant weight to obtain an unsaturated monomer, wherein the mass ratio of butenedioic acid, anhydrous ethanol and mixture a is 3:50:25, and the mass ratio of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol in mixture a is 5.5:4:2.3:32;

[0029] Step A2, mixing graphene oxide and deionized water, ultrasonically treating at an ultrasonic frequency of 30 kHz and an ultrasonic power of 450 w for 20 min to obtain a graphene oxide suspension; at room temperature, adjusting the pH to 8.5 with a 0.8 M sodium hydroxide aqueous solution, adding a mixed solution b of an unsaturated monomer and anhydrous DMF dropwise, and controlling the dripping to be completed within 15 min. After the dripping is completed, heating to 80 ° C. under a nitrogen atmosphere, maintaining the speed constant, stirring and reacting for 15 min, filtering, washing with anhydrous ethanol and deionized water 4 times, and drying at 60 ° C. to constant weight to obtain modified graphene oxide, wherein the mass ratio of graphene oxide to deionized water is 1:100, the mass ratio of graphene oxide suspension to mixed solution b is 25:15, and the mass ratio of unsaturated monomer to anhydrous DMF in mixed solution b is 4:20;

[0030] Step A3: chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and N-hydroxysuccinimide were added to an acetic acid aqueous solution, stirred at 700 rpm for 22 minutes until uniform, then the modified graphene oxide aqueous solution was added, the temperature was raised to 60°C, the speed was maintained constant, and the stirring reaction was continued for 1.5 hours. The mixture was cooled to room temperature, the pH value was adjusted to neutral with a 0.8M sodium hydroxide aqueous solution, the mixture was filtered under reduced pressure, washed with deionized water four times, and dried at 60°C to constant weight to obtain functionalized graphene oxide, wherein the mass ratio of chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, acetic acid aqueous solution, and modified graphene oxide aqueous solution was 0.6:3.5:2.8:30:49, the modified graphene oxide aqueous solution was obtained by ultrasonically dispersing the modified graphene oxide and deionized water in a mass ratio of 1:10, and the mass fraction of the acetic acid aqueous solution was 0.8%.

[0031] Preparation Example 3

[0032] This preparation example provides a functionalized graphene oxide, which is prepared by the following steps:

[0033] Step A1, adding butenedioic acid to anhydrous ethanol, heating to 46°C, stirring at 550 rpm for 4 minutes until uniform, then adding a mixed solution a of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol, heating to reflux, stirring and reacting for 6 hours. After the reaction, centrifugation is performed, and the precipitate is washed with anhydrous ethanol and deionized water five times in sequence, and dried at 60°C to constant weight to obtain an unsaturated monomer, wherein the mass ratio of butenedioic acid, anhydrous ethanol and mixed solution a is 4:54:28, and the mass ratio of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol in the mixed solution a is 7:5:3.1:32;

[0034] Step A2, mixing graphene oxide and deionized water, ultrasonically treating at an ultrasonic frequency of 35 kHz and an ultrasonic power of 500 w for 24 min to obtain a graphene oxide suspension; at room temperature, adjusting the pH value to 9 with a 1.0 M sodium hydroxide aqueous solution, adding a mixed solution b of an unsaturated monomer and anhydrous DMF dropwise, and controlling the dripping to be completed within 15 min. After the dripping is completed, heating to 85 ° C. under a nitrogen atmosphere, maintaining the speed constant, stirring and reacting for 20 min, filtering, washing with anhydrous ethanol and deionized water 5 times, and drying at 60 ° C. to constant weight to obtain modified graphene oxide, wherein the mass ratio of graphene oxide to deionized water is 1:100, the mass ratio of graphene oxide suspension to mixed solution b is 30:16, and the mass ratio of unsaturated monomer to anhydrous DMF in mixed solution b is 5:20;

[0035] Step A3, chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide were added to an acetic acid aqueous solution, stirred at a speed of 750 rpm for 26 minutes until uniform, then the modified graphene oxide aqueous solution was added, the temperature was raised to 66°C, the speed was maintained constant, and the stirring reaction was continued for 2 hours. The mixture was cooled to room temperature, the pH value was adjusted to neutral with a 1.0 M sodium hydroxide aqueous solution, the mixture was filtered under reduced pressure, washed with deionized water 5 times, and dried at 65°C to constant weight to obtain functionalized graphene oxide, wherein the mass ratio of chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, acetic acid aqueous solution and modified graphene oxide aqueous solution was 0.6:4:3.0:35:52, the modified graphene oxide aqueous solution was obtained by ultrasonically dispersing the modified graphene oxide and deionized water in a mass ratio of 1:10, and the mass fraction of the acetic acid aqueous solution was 1%.

[0036] Comparative Preparation Example 1

[0037] This comparative preparation example provides a functionalized graphene oxide, which is prepared by the following steps:

[0038] Step A1, adding succinic acid to anhydrous ethanol, raising the temperature to 40°C, stirring at 450 rpm for 12 minutes until uniform, then adding a mixture a of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol, raising the temperature to reflux, maintaining the speed constant, and continuing to stir and react for 4 hours. After the reaction is completed, centrifugation is performed, and the precipitate is washed three times with anhydrous ethanol and deionized water in sequence, and dried at 50°C to constant weight to obtain an unsaturated monomer, wherein the mass ratio of succinic acid, anhydrous ethanol and mixture a is 2:46:22, and the mass ratio of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol in mixture a is 4:3:1.5:32;

[0039] Step A2, mixing graphene oxide and deionized water, ultrasonically treating at an ultrasonic frequency of 25 kHz and an ultrasonic power of 400 w for 16 minutes to obtain a graphene oxide suspension; at room temperature, adjusting the pH value to 8 with a 0.6 M sodium hydroxide aqueous solution, adding a mixed solution b of an unsaturated monomer and anhydrous DMF dropwise, and controlling the dripping within 15 minutes. After the dripping is completed, the temperature is raised to 75° C. under a nitrogen atmosphere, the speed is maintained constant, and the reaction is stirred for 10 minutes. Filter, wash with anhydrous ethanol and deionized water three times in sequence, and dry at 55° C. to constant weight to obtain modified graphene oxide, wherein the mass ratio of graphene oxide to deionized water is 1:100, the mass ratio of graphene oxide suspension to mixed solution b is 20:14, and the mass ratio of unsaturated monomer to anhydrous DMF in mixed solution b is 3:20;

[0040] Step A3, chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide were added to an acetic acid aqueous solution, stirred at a speed of 650 rpm for 18 minutes until uniform, then the modified graphene oxide aqueous solution was added, the temperature was raised to 54°C, the speed was maintained constant, and the stirring reaction was continued for 1 hour. The mixture was cooled to room temperature, the pH value was adjusted to neutral with a 0.6M sodium hydroxide aqueous solution, the mixture was filtered under reduced pressure, washed with deionized water three times, and dried at 55°C to constant weight to obtain functionalized graphene oxide, wherein the mass ratio of chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, acetic acid aqueous solution and modified graphene oxide aqueous solution was 0.6:3:2.6:25:46, the modified graphene oxide aqueous solution was obtained by ultrasonically dispersing the modified graphene oxide and deionized water in a mass ratio of 1:10, and the mass fraction of the acetic acid aqueous solution was 0.6%.

[0041] Comparative Preparation Example 2

[0042] This comparative preparation example provides a functionalized graphene oxide, which is prepared by the following steps:

[0043] Step A1, adding butenedioic acid to anhydrous ethanol, heating to 40°C, stirring at 450 rpm for 12 minutes until uniform, then adding a mixture a of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, cyclopentylamine and anhydrous ethanol, heating to reflux, maintaining the speed constant, and continuing to stir and react for 4 hours. After the reaction is completed, centrifugation is performed, and the precipitate is washed three times with anhydrous ethanol and deionized water in sequence, and dried at 50°C to constant weight to obtain an unsaturated monomer, wherein the mass ratio of butenedioic acid, anhydrous ethanol and mixture a is 2:46:22, and the mass ratio of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, cyclopentylamine and anhydrous ethanol in mixture a is 4:3:1.5:32;

[0044] Step A2, mixing graphene oxide and deionized water, ultrasonically treating at an ultrasonic frequency of 25 kHz and an ultrasonic power of 400 w for 16 minutes to obtain a graphene oxide suspension; at room temperature, adjusting the pH value to 8 with a 0.6 M sodium hydroxide aqueous solution, adding a mixed solution b of an unsaturated monomer and anhydrous DMF dropwise, and controlling the dripping within 15 minutes. After the dripping is completed, the temperature is raised to 75° C. under a nitrogen atmosphere, the speed is maintained constant, and the reaction is stirred for 10 minutes. Filter, wash with anhydrous ethanol and deionized water three times in sequence, and dry at 55° C. to constant weight to obtain modified graphene oxide, wherein the mass ratio of graphene oxide to deionized water is 1:100, the mass ratio of graphene oxide suspension to mixed solution b is 20:14, and the mass ratio of unsaturated monomer to anhydrous DMF in mixed solution b is 3:20;

[0045] Step A3, chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide were added to an acetic acid aqueous solution, stirred at a speed of 650 rpm for 18 minutes until uniform, then the modified graphene oxide aqueous solution was added, the temperature was raised to 54°C, the speed was maintained constant, and the stirring reaction was continued for 1 hour. The mixture was cooled to room temperature, the pH value was adjusted to neutral with a 0.6M sodium hydroxide aqueous solution, the mixture was filtered under reduced pressure, washed with deionized water three times, and dried at 55°C to constant weight to obtain functionalized graphene oxide, wherein the mass ratio of chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, acetic acid aqueous solution and modified graphene oxide aqueous solution was 0.6:3:2.6:25:46, the modified graphene oxide aqueous solution was obtained by ultrasonically dispersing the modified graphene oxide and deionized water in a mass ratio of 1:10, and the mass fraction of the acetic acid aqueous solution was 0.6%.

[0046] Preparation Examples 4-6 and Comparative Preparation Examples 3-4 provide a thiol-containing core-shell particle.

[0047] Preparation Example 4

[0048] This preparation example provides a thiolated core-shell particle, which is prepared by the following steps:

[0049] Step B1, ultrasonically dispersing nanomagnetic ferroferric oxide into anhydrous ethanol, controlling the ultrasonic frequency to 25 kHz, the ultrasonic power to 400 W, and the ultrasonic time to 8 min, adding tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water at a speed of 600 pm, and controlling the dripping to be completed within 10 min. After the dripping is completed, the pH is adjusted to 2 with 0.8 M hydrochloric acid water, the temperature is raised to 44 ° C, the temperature is kept stirred for 18 min, and then the temperature is raised to reflux, and the reaction is stirred for 6 h to obtain modified core-shell particles, wherein the mass ratio of nanomagnetic ferroferric oxide, anhydrous ethanol and mixed solution c is 2.4:50:20, and the mass ratio of tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water in the mixed solution c is 12:1:8:3;

[0050] Step B2, the modified core-shell particles, deionized water, anhydrous ethanol and KH-560 were ultrasonically mixed at an ultrasonic frequency of 25 kHz and an ultrasonic power of 400 w for 20 min, stirred at a speed of 650 rpm and reacted at room temperature for 6 h, centrifuged, and the precipitate was washed three times with a 20% mass fraction of ethanol aqueous solution and dried at 55 ° C to constant weight to obtain epoxy core-shell particles. The epoxy core-shell particles and anhydrous DMF were ultrasonically dispersed, the ultrasonic frequency was controlled to 25 kHz, the ultrasonic power was 400 w, and the ultrasonic time was 16 min. Tetrabutylammonium bromide and 2-mercaptoethanol were added dropwise. After the addition of the mixture d of acid and anhydrous DMF, the temperature was raised to 105°C and stirred for 2 hours. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed three times with anhydrous ethanol and deionized water, and dried at 50°C to constant weight to obtain thiolated core-shell particles, wherein the mass ratio of modified core-shell particles, deionized water, anhydrous ethanol and KH-560 was 3:12:30:0.4, the mass ratio of epoxy core-shell particles, anhydrous DMF and the mixture d was 2:44:14, and the mass ratio of tetrabutylammonium bromide, 2-mercaptonicotinic acid and anhydrous DMF in the mixture d was 0.2:1.2:12.

[0051] Preparation Example 5

[0052] This preparation example provides a thiolated core-shell particle, which is prepared by the following steps:

[0053] Step B1, ultrasonically dispersing nanomagnetic ferroferric oxide into anhydrous ethanol, controlling the ultrasonic frequency to 30 kHz, the ultrasonic power to 450 W, and the ultrasonic time to 10 min, adding tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water mixture c dropwise while stirring at a speed of 650 rpm, and controlling the dripping to be completed within 10 min. After the dripping is completed, the pH is adjusted to 2.5 with 1.0 M hydrochloric acid water, the temperature is raised to 48 ° C, the temperature is kept stirred for 20 min, and then the temperature is raised to reflux, and the reaction is stirred for 7 h to obtain modified core-shell particles, wherein the mass ratio of nanomagnetic ferroferric oxide, anhydrous ethanol and mixture c is 2.8:55:23, and the mass ratio of tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water in the mixture c is 13:1:9:4;

[0054] Step B2, the modified core-shell particles, deionized water, anhydrous ethanol and KH-560 were ultrasonically mixed at an ultrasonic frequency of 35kHz and an ultrasonic power of 500w for 25min, stirred at a speed of 600rpm and reacted at room temperature for 7h, centrifuged, and the precipitate was washed 4 times with a 25% mass fraction of ethanol aqueous solution and dried at 60°C to constant weight to obtain epoxy core-shell particles. The epoxy core-shell particles and anhydrous DMF were ultrasonically dispersed, the ultrasonic frequency was controlled to 30kHz, the ultrasonic power was 450w, and the ultrasonic time was 18min. Tetrabutylammonium bromide and 2-mercaptonicotinic acid were added dropwise and anhydrous DMF, and after the addition is completed, the mixture d is heated to 110°C and stirred for 2.5 hours. After the reaction is completed, it is centrifuged, and the precipitate is washed 4 times with anhydrous ethanol and deionized water, and dried at 55°C to constant weight to obtain thiolated core-shell particles, wherein the mass ratio of modified core-shell particles, deionized water, anhydrous ethanol and KH-560 is 4:12:32:0.5, the mass ratio of epoxy core-shell particles, anhydrous DMF and mixture d is 3:47:14, and the mass ratio of tetrabutylammonium bromide, 2-mercaptonicotinic acid and anhydrous DMF in the mixture d is 0.2:1.4:12.

[0055] Preparation Example 6

[0056] This preparation example provides a thiolated core-shell particle, which is prepared by the following steps:

[0057] Step B1, ultrasonically dispersing nanomagnetic ferroferric oxide into anhydrous ethanol, controlling the ultrasonic frequency to 35kHz, the ultrasonic power to 500w, and the ultrasonic time to 12min, adding tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water mixture c dropwise while stirring at a speed of 700rpm, and controlling the dripping to be completed within 10min. After the dripping is completed, the pH is adjusted to 3 with 1.2M hydrochloric acid water, the temperature is raised to 52°C, the mixture is kept stirred for 22min, and then the temperature is raised to reflux, and the reaction is stirred for 8h to obtain modified core-shell particles, wherein the mass ratio of nanomagnetic ferroferric oxide, anhydrous ethanol and mixture c is 3:60:26, and the mass ratio of tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water in the mixture c is 14:1:10:3;

[0058] Step B2, the modified core-shell particles, deionized water, anhydrous ethanol and KH-560 were ultrasonically mixed at an ultrasonic frequency of 30 kHz and an ultrasonic power of 450 W for 30 min, stirred at a speed of 650 rpm and reacted at room temperature for 8 h, centrifuged, and the precipitate was washed 5 times with a 30% mass fraction of ethanol aqueous solution and dried at 65 ° C to constant weight to obtain epoxy core-shell particles. The epoxy core-shell particles and anhydrous DMF were ultrasonically dispersed, the ultrasonic frequency was controlled to 35 kHz, the ultrasonic power was 500 W, and the ultrasonic time was 20 min. Tetrabutylammonium bromide and 2-mercaptoethanol were added dropwise. After the addition of the mixed solution d of acid and anhydrous DMF, the temperature was raised to 115°C and stirred for 3 hours. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed 5 times with anhydrous ethanol and deionized water, and dried at 60°C to constant weight to obtain thiolated core-shell particles, wherein the mass ratio of modified core-shell particles, deionized water, anhydrous ethanol and KH-560 was 5:12:34:0.6, the mass ratio of epoxy core-shell particles, anhydrous DMF and the mixed solution d was 4:50:14, and the mass ratio of tetrabutylammonium bromide, 2-mercaptonicotinic acid and anhydrous DMF in the mixed solution d was 0.2:1.6:12.

[0059] Comparative Preparation Example 3

[0060] This comparative preparation example provides a thiolated core-shell particle, which is prepared by the following steps:

[0061] Step B1, ultrasonically dispersing nanomagnetic ferroferric oxide into anhydrous ethanol, controlling the ultrasonic frequency to 25 kHz, the ultrasonic power to 400 W, and the ultrasonic time to 8 min, adding a mixture c of tetrabutyl titanate, methylammonium bromide, anhydrous ethanol and deionized water dropwise at a speed of 600 pm, and controlling the dripping to be completed within 10 min. After the dripping is completed, the pH is adjusted to 2 with 0.8 M hydrochloric acid water, the temperature is raised to 44 ° C, the mixture is stirred for 18 min, and then the temperature is raised to reflux, and the reaction is stirred for 6 h to obtain modified core-shell particles, wherein the mass ratio of nanomagnetic ferroferric oxide, anhydrous ethanol and the mixture c is 2.4:50:20, and the mass ratio of tetrabutyl titanate, methylammonium bromide, anhydrous ethanol and deionized water in the mixture c is 12:1:8:3;

[0062] Step B2, the modified core-shell particles, deionized water, anhydrous ethanol and KH-560 were ultrasonically mixed at an ultrasonic frequency of 25 kHz and an ultrasonic power of 400 w for 20 min, stirred at a speed of 650 rpm and reacted at room temperature for 6 h, centrifuged, and the precipitate was washed three times with a 20% mass fraction of ethanol aqueous solution and dried at 55 ° C to constant weight to obtain epoxy core-shell particles. The epoxy core-shell particles and anhydrous DMF were ultrasonically dispersed, the ultrasonic frequency was controlled to 25 kHz, the ultrasonic power was 400 w, and the ultrasonic time was 16 min. Tetrabutylammonium bromide and 2-mercaptoethanol were added dropwise. After the addition of the mixture d of acid and anhydrous DMF, the temperature was raised to 105°C and stirred for 2 hours. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed three times with anhydrous ethanol and deionized water, and dried at 50°C to constant weight to obtain thiolated core-shell particles, wherein the mass ratio of modified core-shell particles, deionized water, anhydrous ethanol and KH-560 was 3:12:30:0.4, the mass ratio of epoxy core-shell particles, anhydrous DMF and the mixture d was 2:44:14, and the mass ratio of tetrabutylammonium bromide, 2-mercaptonicotinic acid and anhydrous DMF in the mixture d was 0.2:1.2:12.

[0063] Comparative Preparation Example 4

[0064] This comparative preparation example provides a thiolated core-shell particle, which is prepared by the following steps:

[0065] Step B1, ultrasonically dispersing nanomagnetic ferroferric oxide into anhydrous ethanol, controlling the ultrasonic frequency to 25 kHz, the ultrasonic power to 400 W, and the ultrasonic time to 8 min, adding tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water at a speed of 600 pm, and controlling the dripping to be completed within 10 min. After the dripping is completed, the pH is adjusted to 2 with 0.8 M hydrochloric acid water, the temperature is raised to 44 ° C, the temperature is kept stirred for 18 min, and then the temperature is raised to reflux, and the reaction is stirred for 6 h to obtain modified core-shell particles, wherein the mass ratio of nanomagnetic ferroferric oxide, anhydrous ethanol and mixed solution c is 2.4:50:20, and the mass ratio of tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water in the mixed solution c is 12:1:8:3;

[0066] Step B2, the modified core-shell particles, deionized water, anhydrous ethanol and KH-560 were ultrasonically mixed at an ultrasonic frequency of 25 kHz and an ultrasonic power of 400 w for 20 min, stirred at a speed of 650 rpm at room temperature for 6 h, centrifuged, and the precipitate was washed three times with a 20% ethanol aqueous solution by mass fraction and dried at 55 ° C to constant weight to obtain epoxy core-shell particles. The epoxy core-shell particles and anhydrous DMF were ultrasonically dispersed, the ultrasonic frequency was controlled to 25 kHz, the ultrasonic power was 400 w, and the ultrasonic time was 16 min. Tetrabutylammonium bromide and 3-mercaptoethanol were added dropwise. After the addition of propionic acid and anhydrous DMF mixed solution d, the temperature was raised to 105°C and stirred for 2 hours. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed three times with anhydrous ethanol and deionized water, and dried at 50°C to constant weight to obtain thiolated core-shell particles, wherein the mass ratio of modified core-shell particles, deionized water, anhydrous ethanol and KH-560 was 3:12:30:0.4, the mass ratio of epoxy core-shell particles, anhydrous DMF and mixed solution d was 2:44:14, and the mass ratio of tetrabutylammonium bromide, 3-mercaptopropionic acid and anhydrous DMF in the mixed solution d was 0.2:1.2:12.

[0067] Examples 1-3 and Comparative Examples 1-4 provide a magnetic graphene-based composite material for degrading dyes.

[0068] Example 1

[0069] This embodiment provides a magnetic graphene-based composite material for dye degradation, comprising the following raw materials in parts by weight: 36 parts of functionalized graphene oxide prepared in Preparation Example 1, 6 parts of thiolated core-shell particles prepared in Preparation Example 4, 0.02 parts of sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate, and 320 parts of deionized water;

[0070] The preparation method of the magnetic graphene-based composite material for degrading dyes comprises the following steps:

[0071] Functionalized graphene oxide was ultrasonically dispersed in deionized water, and the ultrasonic frequency was controlled to be 35kHz, the ultrasonic power was 500w, and the ultrasonic time was 16min. The temperature was raised to 60°C while stirring at a speed of 550rpm. Then, thiol core-shell particles and sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate were added. The speed was maintained unchanged and stirring was continued for 12min until uniform. Then, the mixture was placed in a 365nm wavelength peak and an intensity of 80mw / cm 2 The product was placed under ultraviolet light for 10 minutes, the rotary evaporation temperature was controlled at 50°C, and the deionized water was removed by rotary evaporation. The product was washed with deionized water for 3 times and dried at 60°C to constant weight to obtain a magnetic graphene-based composite material for dye degradation.

[0072] Example 2

[0073] This embodiment provides a magnetic graphene-based composite material for dye degradation, comprising the following raw materials in parts by weight: 40 parts of functionalized graphene oxide prepared in Preparation Example 2, 7 parts of thiolated core-shell particles prepared in Preparation Example 5, 0.04 parts of sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate, and 340 parts of deionized water;

[0074] The preparation method of the magnetic graphene-based composite material for degrading dyes comprises the following steps:

[0075] Functionalized graphene oxide was ultrasonically dispersed in deionized water, with the ultrasonic frequency controlled at 30 kHz, the ultrasonic power at 450 W, and the ultrasonic time at 20 min. The temperature was raised to 65 ° C while stirring at a speed of 600 rpm. Then, thiol core-shell particles and sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate were added. The speed was maintained constant and stirring was continued for 14 min until uniform. The mixture was then placed in a 365 nm wavelength peak and an intensity of 80 mW / cm 2 The product was irradiated under ultraviolet light for 15 minutes, the rotary evaporation temperature was controlled at 55°C, the deionized water was removed by rotary evaporation, the product was washed with deionized water 4 times, and the product was dried at 65°C to constant weight to obtain a magnetic graphene-based composite material for dye degradation.

[0076] Example 3

[0077] This embodiment provides a magnetic graphene-based composite material for dye degradation, comprising the following raw materials in parts by weight: 44 parts of functionalized graphene oxide prepared in Preparation Example 3, 8 parts of thiolated core-shell particles prepared in Preparation Example 6, 0.06 parts of sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate, and 360 parts of deionized water;

[0078] The preparation method of the magnetic graphene-based composite material for degrading dyes comprises the following steps:

[0079] Functionalized graphene oxide was ultrasonically dispersed in deionized water, with the ultrasonic frequency controlled at 25 kHz, the ultrasonic power at 400 W, and the ultrasonic time at 24 min. The temperature was raised to 70 ° C while stirring at a speed of 650 rpm. Then, thiol core-shell particles and sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate were added. The speed was maintained constant and stirring was continued for 16 min until uniform. The mixture was then placed in a 365 nm wavelength peak and an intensity of 80 mW / cm 2 The product was irradiated under ultraviolet light for 20 minutes, the rotary evaporation temperature was controlled at 60°C, the deionized water was removed by rotary evaporation, the product was washed with deionized water 5 times, and the product was dried at 70°C to constant weight to obtain a magnetic graphene-based composite material for dye degradation.

[0080] Comparative Example 1

[0081] This comparative example provides a magnetic graphene-based composite material for dye degradation, comprising the following raw materials in parts by weight: 36 parts of functionalized graphene oxide prepared in Comparative Preparation Example 1, 6 parts of thiolated core-shell particles prepared in Preparation Example 4, 0.02 parts of sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate, and 320 parts of deionized water;

[0082] The preparation method of the magnetic graphene-based composite material for degrading dyes comprises the following steps:

[0083] Functionalized graphene oxide was ultrasonically dispersed in deionized water, and the ultrasonic frequency was controlled to be 35kHz, the ultrasonic power was 500w, and the ultrasonic time was 16min. The temperature was raised to 60°C while stirring at a speed of 550rpm. Then, thiol core-shell particles and sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate were added. The speed was maintained unchanged and stirring was continued for 12min until uniform. Then, the mixture was placed in a 365nm wavelength peak and an intensity of 80mw / cm 2 The product was placed under ultraviolet light for 10 minutes, the rotary evaporation temperature was controlled at 50°C, and the deionized water was removed by rotary evaporation. The product was washed with deionized water for 3 times and dried at 60°C to constant weight to obtain a magnetic graphene-based composite material for dye degradation.

[0084] Comparative Example 2

[0085] This comparative example provides a magnetic graphene-based composite material for dye degradation, comprising the following raw materials in parts by weight: 36 parts of functionalized graphene oxide prepared in Comparative Preparation Example 2, 6 parts of thiolated core-shell particles prepared in Preparation Example 4, 0.02 parts of sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate, and 320 parts of deionized water;

[0086] The preparation method of the magnetic graphene-based composite material for degrading dyes comprises the following steps:

[0087] Functionalized graphene oxide was ultrasonically dispersed in deionized water, and the ultrasonic frequency was controlled to be 35kHz, the ultrasonic power was 500w, and the ultrasonic time was 16min. The temperature was raised to 60°C while stirring at a speed of 550rpm. Then, thiol core-shell particles and sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate were added. The speed was maintained unchanged and stirring was continued for 12min until uniform. Then, the mixture was placed in a 365nm wavelength peak and an intensity of 80mw / cm 2 The product was placed under ultraviolet light for 10 minutes, the rotary evaporation temperature was controlled at 50°C, and the deionized water was removed by rotary evaporation. The product was washed with deionized water for 3 times and dried at 60°C to constant weight to obtain a magnetic graphene-based composite material for dye degradation.

[0088] Comparative Example 3

[0089] This comparative example provides a magnetic graphene-based composite material for dye degradation, comprising the following raw materials in parts by weight: 36 parts of functionalized graphene oxide prepared in Preparation Example 1, 6 parts of thiolated core-shell particles prepared in Comparative Preparation Example 3, 0.02 parts of sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate, and 320 parts of deionized water;

[0090] The preparation method of the magnetic graphene-based composite material for degrading dyes comprises the following steps:

[0091] Functionalized graphene oxide was ultrasonically dispersed in deionized water, and the ultrasonic frequency was controlled to be 35kHz, the ultrasonic power was 500w, and the ultrasonic time was 16min. The temperature was raised to 60°C while stirring at a speed of 550rpm. Then, thiol core-shell particles and sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate were added. The speed was maintained unchanged and stirring was continued for 12min until uniform. Then, the mixture was placed in a 365nm wavelength peak and an intensity of 80mw / cm 2 The product was placed under ultraviolet light for 10 minutes, the rotary evaporation temperature was controlled at 50°C, and the deionized water was removed by rotary evaporation. The product was washed with deionized water for 3 times and dried at 60°C to constant weight to obtain a magnetic graphene-based composite material for dye degradation.

[0092] Comparative Example 4

[0093] This comparative example provides a magnetic graphene-based composite material for dye degradation, comprising the following raw materials in parts by weight: 36 parts of functionalized graphene oxide prepared in Preparation Example 1, 6 parts of thiolated core-shell particles prepared in Comparative Preparation Example 4, 0.02 parts of sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate, and 320 parts of deionized water;

[0094] The preparation method of the magnetic graphene-based composite material for degrading dyes comprises the following steps:

[0095] Functionalized graphene oxide was ultrasonically dispersed in deionized water, and the ultrasonic frequency was controlled to be 35kHz, the ultrasonic power was 500w, and the ultrasonic time was 16min. The temperature was raised to 60°C while stirring at a speed of 550rpm. Then, thiol core-shell particles and sodium 2-hydroxy-3-(4-benzoylphenoxy)propanesulfonate were added. The speed was maintained unchanged and stirring was continued for 12min until uniform. Then, the mixture was placed in a 365nm wavelength peak and an intensity of 80mw / cm 2 The product was placed under ultraviolet light for 10 minutes, the rotary evaporation temperature was controlled at 50°C, and the deionized water was removed by rotary evaporation. The product was washed with deionized water for 3 times and dried at 60°C to constant weight to obtain a magnetic graphene-based composite material for dye degradation.

[0096] Performance Testing

[0097] Performance testing

[0098] Adsorption performance: Taking methylene blue solution as an example, the adsorption and degradation performance of the magnetic graphene-based composite material for dye degradation prepared in this application was simulated.

[0099] 200 mL of a prepared 50 mg / L methylene blue solution was added to a reaction tube, and 0.5 g of the magnetic graphene-based composite material for dye degradation prepared in Examples 1-4 and Comparative Examples 1-3 was added as a catalyst, respectively. The mixture was placed in a dark place and stirred for 0.5 h. The concentration of the reaction solution was tested and the adsorption rate was calculated. The mixture was then placed in a photocatalytic reactor, a constant flow of air was introduced, a 300 W high-pressure mercury lamp was used as an ultraviolet light source, the wavelength of the light was 365 nm, and the vertical distance between the light source and the solution was 10 cm. After the photoreaction, 5 mL of the dispersion was removed from the reaction system every 30 min and placed in a centrifuge tube. The supernatant was taken and the absorbance and concentration of the methylene blue in the solution were tested using a U3900 UV-visible spectrophotometer. The degradation rate after treatment was calculated. The degradation rate calculation formula is shown in formula (1).

[0100] (1)

[0101] Where D is the degradation rate, C0, C, A0, and A represent the initial concentration and concentration after treatment, initial absorbance, and absorbance after treatment of the solution, respectively. The test results are shown in Table 1.

[0102] Table 1 Adsorption and degradation performance tests of graphene-based composite materials prepared in Examples 1-3 and Comparative Examples 1-4

[0103]

[0104] It can be seen from Table 1 that, compared with Comparative Examples 1-4, the graphene-based composite materials for degrading dyes prepared in Examples 1-3 have more excellent adsorption and degradation properties.

[0105] 2. Antibacterial properties

[0106] Bacterial inhibition rate: Escherichia coli and Staphylococcus aureus were used as bacterial models. The oscillation method was used to detect the bacterial count in the culture medium to determine the bacterial inhibition rate of the adsorption material after five uses. The test results are shown in Table 2:

[0107] Table 2 Antibacterial performance test of graphene-based composite materials prepared in Examples 1-3 and Comparative Examples 1-4

[0108]

[0109] As can be seen from Table 2, compared with Comparative Examples 1-4, the magnetic graphene-based composite materials for dye degradation prepared in Examples 1-3 have more excellent antibacterial properties.

[0110] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A magnetic graphene-based composite material for degrading dyes, characterized in that: The method comprises the following raw materials in parts by weight: 36-44 parts of functionalized graphene oxide, 6-8 parts of thiol core-shell particles, 0.02-0.06 parts of photoinitiator and 320-360 parts of deionized water; The functionalized graphene oxide is firstly prepared by amidation reaction of maleic acid and aniline to obtain an unsaturated monomer, which is then further amidated with graphene oxide to obtain modified graphene oxide, and finally amidated with chitosan to obtain the functionalized graphene oxide. The thiolated core-shell particles are first prepared by a sol-gel method from nano-magnetic ferrosoferric oxide, hexadecyltrimethylammonium bromide, tetrabutyl titanate, anhydrous ethanol and deionized water to obtain a mixed solution C, which is then heat-treated to obtain modified core-shell particles, which are then modified with KH-560 and finally prepared by a ring-opening esterification reaction with 2-mercaptonicotinic acid.

2. The magnetic graphene-based composite material for dye degradation according to claim 1, characterized in that: The functionalized graphene oxide is prepared by the following steps: Step A1: adding butenedioic acid to anhydrous ethanol, heating to 40-46° C., stirring evenly, then adding a mixture of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline, and anhydrous ethanol (a), heating to reflux, stirring and reacting for 4-6 hours. After the reaction is complete, centrifuging, washing, and drying the precipitate to obtain an unsaturated monomer; Step A2, mixing graphene oxide and deionized water, and ultrasonically dispersing to obtain a graphene oxide suspension; at room temperature, adjusting the pH to 8-9, and adding a mixture of unsaturated monomer and anhydrous DMF dropwise within 15 minutes. After the addition is completed, the mixture is heated to 75-85° C. under a nitrogen atmosphere, maintaining the rotation speed unchanged, and stirred for 10-20 minutes. The mixture is filtered, washed, and dried to obtain modified graphene oxide; Step A3: chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and N-hydroxysuccinimide are added to an acetic acid aqueous solution and stirred evenly. Then, the modified graphene oxide aqueous solution is added, the temperature is raised to 54-66° C., the mixture is stirred for 1-2 hours, and the mixture is cooled to room temperature. The pH value is adjusted to neutral, the mixture is filtered under reduced pressure, washed, and dried to obtain functionalized graphene oxide.

3. The magnetic graphene-based composite material for degrading dyes according to claim 2, characterized in that: In step A1, the mass ratio of butenedioic acid, anhydrous ethanol and mixed solution a is 2-4:46-54:22-28, and the mass ratio of N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, aniline and anhydrous ethanol in mixed solution a is 4-7:3-5:1.5-3.1:

32.

4. The magnetic graphene-based composite material for dye degradation according to claim 2, characterized in that: In step A2, the mass ratio of graphene oxide to deionized water is 1:100, the mass ratio of graphene oxide suspension to mixed solution b is 20-30:14-16, and in mixed solution b, the mass ratio of unsaturated monomer to anhydrous DMF is 3-5:

20.

5. The magnetic graphene-based composite material for dye degradation according to claim 2, characterized in that: In step A3, the mass ratio of chitosan, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide, acetic acid aqueous solution, and modified graphene oxide aqueous solution is 0.6:3-4:2.6-3.0:25-35:46-52. The modified graphene oxide aqueous solution is obtained by ultrasonically dispersing the modified graphene oxide and deionized water in a mass ratio of 1:

10. The mass fraction of the acetic acid aqueous solution is 0.6-1%.

6. The magnetic graphene-based composite material for dye degradation according to claim 1, characterized in that: The thiol core-shell particles are prepared by the following steps: Step B1, ultrasonically dispersing nano-magnetic ferroferric oxide into anhydrous ethanol, adding a mixture C of tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water dropwise, and controlling the addition to be completed within 10 minutes. After completion of the addition, adjusting the pH to 2-3, heating to 44-52° C., stirring at this temperature for 18-22 minutes, then heating to reflux, stirring and reacting for 6-8 hours to obtain modified core-shell particles; Step B2, ultrasonically mixing the modified core-shell particles, deionized water, anhydrous ethanol and KH-560 for 20-30 minutes, stirring at room temperature for 6-8 hours, centrifuging, washing and drying the precipitate to obtain epoxy core-shell particles, ultrasonically dispersing the epoxy core-shell particles and anhydrous DMF, and adding dropwise a mixture of tetrabutylammonium bromide, 2-mercaptonicotinic acid and anhydrous DMF. After the addition is completed, the temperature is raised to 105-115° C. and stirred for 2-3 hours. After the reaction is completed, centrifugation is performed, and the precipitate is washed and dried to obtain thiolated core-shell particles.

7. The magnetic graphene-based composite material for dye degradation according to claim 6, characterized in that: In step B1, the mass ratio of nanomagnetic ferrosoferric oxide, anhydrous ethanol and mixed solution C is 2.4-3.2:50-60:20-26. In the mixed solution C, the mass ratio of tetrabutyl titanate, hexadecyltrimethylammonium bromide, anhydrous ethanol and deionized water is 12-14:1:8-10:3-5.

8. The magnetic graphene-based composite material for dye degradation according to claim 6, characterized in that: In step B2, the mass ratio of the modified core-shell particles, deionized water, anhydrous ethanol, and KH-560 is 3-5:12:30-34:0.4-0.6, the mass ratio of the epoxy core-shell particles, anhydrous DMF, and the mixed solution d is 2-4:44-50:14, and in the mixed solution d, the mass ratio of tetrabutylammonium bromide, 2-mercaptonicotinic acid, and anhydrous DMF is 0.2:1.2-1.6:

12.

9. A method for preparing the magnetic graphene-based composite material for degrading dyes according to any one of claims 1 to 8, characterized in that: The following steps are involved: Functionalized graphene oxide is ultrasonically dispersed in deionized water, heated to 60-70°C, and then thiol core-shell particles and a photoinitiator are added. The mixture is stirred evenly, irradiated with ultraviolet light for 10-20 minutes, rotary evaporated, washed, and dried to obtain a magnetic graphene-based composite material for dye degradation.

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