Application of graphene oxide / metal-organic framework modified magnetic nanoparticles as perchlorate extraction material

Abstract

The application belongs to the technical field of perchlorate treatment, and discloses application of graphene oxide / metal organic framework modified magnetic nanoparticles as a perchlorate extraction material, and an application method is provided: graphene oxide / metal organic framework modified magnetic nanoparticles Fe3O4@GO@MIL-53(Al)-NH2 are added into perchlorate wastewater, perchlorate is quickly extracted under the action of an external mechanical stirring, then used Fe3O4@GO@MIL-53(Al)-NH2 is separated and recovered by means of a magnetic field, and purified water is obtained. In the application, Fe3O4@GO@MIL-53(Al)-NH2 takes magnetic ferroferric oxide as a core, and a composite functional group composed of graphene oxide and a metal organic framework material on the surface, is used for extracting perchlorate, and has the advantages of fast extraction speed, high extraction efficiency, easy regeneration and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of perchlorate treatment, and particularly relates to application of graphene oxide / metal organic framework modified magnetic nanoparticles as a perchlorate extraction material. BACKGROUND

[0002] Perchlorate is a toxic inorganic chemical substance, and in recent years, the safety problem of perchlorate has been paid more and more attention, so it is of great significance to monitor and remove perchlorate in environmental water samples. The removal of perchlorate can be divided into physical removal and chemical removal, wherein the commonly used chemical reactions include chemical degradation, electrochemical degradation and catalytic degradation, etc., but generally the operation is complex, the removal efficiency is not high, and other catalysts and chemical reagents need to be added in the reaction process, which is easy to cause secondary pollution.

[0003] Compared with chemical removal, physical removal has the advantages of simple operation process and high removal efficiency, and the physical removal mainly realizes the proton transfer of perchlorate in water body through adsorption and other forces to achieve the removal effect, and the main methods include adsorption, ion exchange and membrane filtration, etc. Activated carbon is the earliest material applied to the removal of perchlorate, and on this basis, carbon nanotubes, chitosan and other materials are also applied to the removal of perchlorate in water samples. These materials have the advantages of low cost, but these materials only rely on physical adsorption of pore structure and other physical adsorption of adsorption materials, the adsorption kinetics is slow, which leads to long processing time and reduces the processing efficiency, and it is difficult to regenerate these materials after adsorbing perchlorate, which is not conducive to recycling. SUMMARY

[0004] The technical problem to be solved by the present application is to provide the application of graphene oxide / metal organic framework modified magnetic nanoparticles as a perchlorate extraction material, which solves the problems existing in the prior art. The material takes magnetic ferroferric oxide as the core, and the surface is a composite functional group composed of graphene oxide and metal organic framework material, which is used for extracting perchlorate and has the advantages of fast extraction speed, high extraction efficiency and easy regeneration.

[0005] To solve the technical problems proposed in the present application, the application of graphene oxide / metal organic framework modified magnetic nanoparticles as a perchlorate extraction material is provided, and the graphene oxide / metal organic framework modified magnetic nanoparticles Fe3O4@GO@MIL-53(Al)-NH2 is added to the perchlorate wastewater, and under the action of external mechanical stirring, the perchlorate is quickly extracted, then the used Fe3O4@GO@MIL-53(Al)-NH2 is recovered by means of magnetic field, and the purified water is obtained.

[0006] In the scheme, the Fe3O4@GO@MIL-53(Al)-NH2 is composed of magnetic magnetite, graphene oxide and metal organic framework material MIL-53(Al)-NH2, with the magnetic magnetite as the core and the composite functional group of graphene oxide and MIL-53(Al)-NH2 on the surface.

[0007] In the scheme, the particle size of the Fe3O4@GO@MIL-53(Al)-NH2 is 5-25nm, the specific surface area is 80-120m 2 / g, and the pore diameter is 1-1.3nm.

[0008] In the scheme, the perchlorate wastewater mainly comes from fireworks and firecrackers enterprises, with pH of 6-8 and perchlorate concentration of 100-200μg / L.

[0009] Further, the perchlorate is one or more of sodium perchlorate, potassium perchlorate and lithium perchlorate.

[0010] In the scheme, the dosage of the Fe3O4@GO@MIL-53(Al)-NH2 in the perchlorate wastewater is 1-2g / L, the extraction amount of the perchlorate is 80-90μg / g, and the removal efficiency is 80-90%.

[0011] In the scheme, the extraction temperature is 20-25℃, the extraction time is 2-3min, and the mechanical stirring rate during extraction is 600-800rpm.

[0012] In the scheme, the preparation method of the Fe3O4@GO@MIL-53(Al)-NH2 comprises the following steps:

[0013] 1) Dissolve ferric chloride and ferrous dichloride in water, then heat to the reaction temperature under nitrogen protection, and then add ammonia water dropwise for reaction, wash the product with water to neutral after the reaction, and dry to obtain magnetic nanoparticles Fe3O4;

[0014] 2) Dissolve the magnetic nanoparticles Fe3O4 and 3-aminopropyltrimethoxysilane in an ethanol aqueous solution, heat to the reaction temperature under weak acid conditions for reaction, then add graphene oxide for further reaction, wash the product with methanol and water in sequence after the reaction, and dry to obtain graphene oxide modified magnetic nanoparticles Fe3O4@GO;

[0015] 3) adding graphene oxide modified magnetic nanoparticles Fe3O4@GO, aluminum trichloride and 2-amino terephthalic acid into water, ultrasonic dispersion, then heating to reaction temperature for reaction, after reaction, washing the product with water and N,N-dimethylformamide in turn, drying to obtain graphene oxide / metal organic framework modified magnetic nanoparticles Fe3O4@GO@MIL-53(Al)-NH2.

[0016] Further, in step 1), the molar ratio of ferric trichloride and ferric dichloride is 1:(0.4-0.5), and the molar amount of ferric trichloride to the volume of water for dissolution is 1 mol:(250-500) mL.

[0017] Further, the mass fraction of the ammonia water is 25-28%, and the molar amount of ferric trichloride to the volume of ammonia water is 1 mol:(20-25) mL.

[0018] Further, the reaction temperature in step 1) is 80-90℃, and the reaction time is 10-12h.

[0019] Further, the drying in step 1), step 2) and step 3) is all vacuum drying, and the drying temperature is 60-70℃.

[0020] Further, the mass ratio of the magnetic nanoparticles Fe3O4, 3-aminopropyltrimethoxysilane and graphene oxide is 1:(2.5-3.0):(0.5-0.8).

[0021] Further, the volume fraction of the ethanol aqueous solution is 40-60%, and the mass of the magnetic nanoparticles Fe3O4 to the volume of the ethanol aqueous solution is 1 g:(100-150) mL.

[0022] Further, the weak acid condition is pH 4-5, and the pH is adjusted by 1-2 mol / L glacial acetic acid.

[0023] Further, the reaction temperature in step 2) is 60-70℃, and the reaction is continued for 10-12h before adding graphene oxide, and for 10-12h after adding graphene oxide.

[0024] Further, the mass ratio of the graphene oxide modified magnetic nanoparticles Fe3O4@GO, aluminum trichloride and 2-amino terephthalic acid is 1:(0.7-0.8):(0.5-0.6).

[0025] Further, in step 3), the mass of the graphene oxide modified magnetic nanoparticles Fe3O4@GO to the volume of water for reaction is 1 g:(80-100) mL.

[0026] Further, the reaction temperature in step 3) is 150-160 DEG C, and the reaction time is 10-12 h.

[0027] In the above scheme, the used Fe3O4@GO@MIL-53(Al)-NH2 is regenerated by the following method: the used Fe3O4@GO@MIL-53(Al)-NH2 is added into an eluent, and perchlorate is eluted in an ultrasonic cleaner, then recovered by means of a magnetic field, dried, to obtain regenerated Fe3O4@GO@MIL-53(Al)-NH2.

[0028] Further, the eluent is a potassium chloride aqueous solution, and the concentration is 10-50 mmol / L.

[0029] Further, the mass of the used Fe3O4@GO@MIL-53(Al)-NH2 to the volume of the eluent is 1 g:(10-20) mL.

[0030] Further, the elution time of the used Fe3O4@GO@MIL-53(Al)-NH2 in the ultrasonic cleaner is 30-60 min.

[0031] In the above scheme, the extraction amount of perchlorate by the regenerated Fe3O4@GO@MIL-53(Al)-NH2 is more than 80% of the extraction amount of perchlorate by the unused Fe3O4@GO@MIL-53(Al)-NH2, and the regenerated Fe3O4@GO@MIL-53(Al)-NH2 can be regenerated for 5-10 times.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] 1) The present application prepares a new graphene oxide (GO) / metal organic framework (MOFs) modified magnetic nanoparticle, which combines the advantages of GO and MOFs, has the advantages of large specific surface area and small pore diameter, and is used as an extraction material for perchlorate in perchlorate wastewater.

[0034] 2) The application is to improve the adsorption rate, and a composite functional group composed of graphene oxide and metal organic framework material is modified on the surface of the magnetic ferroferric oxide core; since the magnetic nanoparticle Fe3O4 surface itself has no functional group, the Fe3O4@GO synthesized on this basis has poor action force, therefore, a layer of organic silicon coating is wrapped on the surface of Fe3O4 by 3-aminopropyl trimethoxysilane, and the amino on the surface is easy to react with the polar groups such as hydroxyl, carboxyl and epoxy glue on the surface of GO, so as to improve the reaction efficiency and stability of Fe3O4@GO; then, aluminum trioxide and 2-amino terephthalic acid are selected to synthesize MOFs (MIL-53 (Al)-NH2), the material has good water stability, and the existence of the amino in MIL-53 (Al)-NH2 helps to chemically react with the hydroxyl and carboxyl in Fe3O4@GO and enhance the conjugation effect of the lone pair electrons in the nanoparticle and perchlorate, so as to improve the reaction efficiency of Fe3O4@GO@MIL-53 (Al)-NH2 and the stability of the material. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The TEM diagram of Fe3O4@GO@MIL-53 (Al)-NH2 prepared in Example 1 of the application.

[0036] Figure 2 The FTIR diagram of Fe3O4@GO and Fe3O4@GO@MIL-53 (Al)-NH2 prepared in Example 1 of the application.

[0037] Figure 3 The XRD diagram of Fe3O4@GO and Fe3O4@GO@MIL-53 (Al)-NH2 prepared in Example 1 of the application. DETAILED DESCRIPTION

[0038] In order to better understand the application, the content of the application is further illustrated below in combination with examples, but the content of the application is not limited to the examples below.

[0039] Example 1

[0040] The preparation method of the graphene oxide / metal organic framework modified magnetic nanoparticle in the embodiment comprises the following steps:

[0041] 1) 0.4 mol of ferric chloride and 0.2 mol of ferrous dichloride are dissolved in 200 mL of pure water, and then 10 mL of ammonia water is added dropwise under the protection of nitrogen, and the reaction is carried out for 12 h, the mass fraction of the used ammonia water is 25%, after the reaction is completed, the product is washed with water until it is neutral, and then it is dried in a vacuum drying oven at 60℃, so as to obtain the magnetic nanoparticle Fe3O4;

[0042] 2) 1 g of magnetic nanoparticles Fe3O4 and 3 g of 3-aminopropyltrimethoxysilane were dissolved in 150 mL of an ethanol aqueous solution, the volume fraction of the ethanol aqueous solution used was 50%, after the pH of the system was adjusted to 4 with 1 mol / L glacial acetic acid, the system was heated to 60°C and reacted for 12 h, then 0.5 g of graphene oxide was added and the reaction was continued for 12 h, after the reaction was completed, the product was washed with methanol and pure water in turn, and was dried in a vacuum drying oven at 60°C to obtain graphene oxide modified magnetic nanoparticles Fe3O4@GO;

[0043] 3) 1.4 g of Fe3O4@GO, 1 g of aluminum trichloride and 0.8 g of 2-amino terephthalic acid were added to 120 mL of water and ultrasonically dispersed, then the system was heated to 150°C in a hydrothermal reaction kettle and reacted for 12 h, after the reaction was completed, the product was washed with pure water and N,N-dimethylformamide in turn, and was dried in a vacuum drying oven at 60°C to obtain graphene oxide / metal organic framework modified magnetic nanoparticles Fe3O4@GO@MIL-53(Al)-NH2.

[0044] Figure 1 The TEM image of Fe3O4@GO@MIL-53(Al)-NH2 prepared in this example is shown in the figure, from which it can be seen that the size of Fe3O4@GO@MIL-53(Al)-NH2 is uniform, and the particle size is 5-25 nm. It was detected that the specific surface area thereof was 86.56 m 2 / g, and the pore diameter was 1.0-1.2 nm.

[0045] Figure 2 The FTIR images of Fe3O4@GO and Fe3O4@GO@MIL-53(Al)-NH2 prepared in this example are shown in the figure, the FTIR image of Fe3O4@GO@MIL-53(Al)-NH2 shows that the absorption peak at 580 cm -1 is the Fe-O stretching vibration peak in Fe3O4, the absorption peaks at 3382 cm -1 and 3496 cm -1 are O-H and N-H stretching vibration peaks respectively, the absorption peaks at 1574 cm -1 and 1388 cm -1 are C=O and C-O stretching vibration peaks respectively, and these characteristic absorption peaks indicate that Fe3O4@GO@MIL-53(Al)-NH2 is successfully prepared on the surface of Fe3O4.

[0046] Figure 3The XRD pattern of Fe3O4@GO and Fe3O4@GO@MIL-53(Al)-NH2 prepared in this example can be seen from the figure, the spectrum of Fe3O4@GO and Fe3O4@GO@MIL-53(Al)-NH2 is in good agreement, which shows that Fe3O4@GO@MIL-53(Al)-NH2 is successfully synthesized on the surface of Fe3O4@GO, and the crystal structure does not change significantly.

[0047] Fe3O4@GO@MIL-53(Al)-NH2 prepared in this example was applied as perchlorate extraction material to the treatment of perchlorate wastewater. The perchlorate wastewater to be treated was from a firework enterprise, with pH of 7, temperature of 25℃, containing sodium perchlorate, ammonium perchlorate and lithium perchlorate, and perchlorate concentration of 200μg / L. The application method was: Fe3O4@GO@MIL-53(Al)-NH2 was added to the perchlorate wastewater to be treated, the dosage was 2g / L, and extraction was carried out under the stirring speed of 700rpm for 2min, then the used Fe3O4@GO@MIL-53(Al)-NH2 was recovered by magnetic field, and the purified water was obtained.

[0048] It was detected that the extraction amount of Fe3O4@GO@MIL-53(Al)-NH2 to perchlorate was 83μg / g, the perchlorate concentration in the purified water was 34μg / L, and the removal rate was 83%.

[0049] The used Fe3O4@GO@MIL-53(Al)-NH2 was regenerated, and the regeneration method was: 1g of the used Fe3O4@GO@MIL-53(Al)-NH2 was added into 20mL of potassium chloride aqueous solution with concentration of 10mmol / L, eluted in the ultrasonic cleaning instrument for 60min, then recovered by magnetic field, and dried in the vacuum drying oven at 60℃ to obtain regenerated Fe3O4@GO@MIL-53(Al)-NH2.

[0050] The regenerated Fe3O4@GO@MIL-53(Al)-NH2 was again used as perchlorate extraction material for the treatment of perchlorate wastewater, and the application conditions were consistent with the first application. It was detected that the extraction amount of the regenerated Fe3O4@GO@MIL-53(Al)-NH2 to perchlorate was 78.5μg / g, which was 94.6% of the extraction amount of the unused Fe3O4@GO@MIL-53(Al)-NH2, and still maintained excellent extraction performance.

[0051] Example 2

[0052] The preparation method of graphene oxide / metal organic framework modified magnetic nanoparticles in this example comprises the following steps:

[0053] 1) 0.5 mol of ferric chloride and 0.23 mol of ferrous dichloride were dissolved in 250 mL of pure water, and the solution was heated to 85°C under nitrogen protection, then 12 mL of ammonia water was added dropwise, and the reaction was carried out for 12 h. The mass fraction of the ammonia water used was 25%. After the reaction, the product was washed with water until it was neutral, and then it was dried in a vacuum drying oven at 60°C to obtain magnetic nanoparticles Fe3O4.

[0054] 2) 2 g of magnetic nanoparticles Fe3O4 and 5 g of 3-aminopropyltrimethoxysilane were dissolved in 200 mL of an ethanol aqueous solution, and the volume fraction of the ethanol aqueous solution used was 50%. After the pH of the system was adjusted to 4 with 1 mol / L glacial acetic acid, the solution was heated to 60°C and reacted for 12 h. Then, 1.2 g of graphene oxide was added and the reaction was continued for 12 h. After the reaction, the product was washed with methanol and pure water, and then it was dried in a vacuum drying oven at 60°C to obtain graphene oxide modified magnetic nanoparticles Fe3O4@GO.

[0055] 3) 2 g of Fe3O4@GO, 1.5 g of aluminum trichloride, and 1 g of 2-amino terephthalic acid were added to 200 mL of water and ultrasonically dispersed, and then the solution was heated to 150°C in a hydrothermal reactor and reacted for 12 h. After the reaction, the product was washed with pure water and N,N-dimethylformamide, and then it was dried in a vacuum drying oven at 60°C to obtain graphene oxide / metal-organic framework modified magnetic nanoparticles Fe3O4@GO@MIL-53(Al)-NH2.

[0056] The Fe3O4@GO@MIL-53(Al)-NH2 prepared in this example was applied as a perchlorate extraction material for the treatment of perchlorate wastewater. The perchlorate wastewater to be treated was obtained from a fireworks and firecracker enterprise, and had a pH of 7 and a temperature of 25°C. The perchlorate salts contained in the wastewater were sodium perchlorate, ammonium perchlorate, and lithium perchlorate, and the concentration of the perchlorate salts was 100 μg / L. The application method was as follows: Fe3O4@GO@MIL-53(Al)-NH2 was added to the perchlorate wastewater to be treated, and the dosage was 1 g / L. The mixture was extracted for 2 min at a stirring speed of 800 rpm, and then the used Fe3O4@GO@MIL-53(Al)-NH2 was recovered by means of a magnetic field. The purified water was obtained.

[0057] It was detected that the extraction amount of perchlorate by Fe3O4@GO@MIL-53(Al)-NH2 was 81.6 μg / g, and the concentration of perchlorate in the purified water was 18.4 μg / L, and the removal rate was 81.6%.

[0058] Comparative Example 1

[0059] Comparative Example 1 and Example 1 differ only in that the metal-organic framework material used was MOF-199.

[0060] Step 3) is adjusted as follows: 0.52 g of 1,3,5-benzenetricarboxylic acid, 0.8 g of Cu(OAc) H2O and 1 g of Fe3O4@GO are dissolved in 36 mL of mixed solvent (DMF / ethanol / pure water, 1 / 1 / 1, v / v / v), 1 mL of triethylamine is added after uniform mixing, stirring is performed at room temperature for 24 h, the product is washed with DMF after completion of stirring, and is placed in a vacuum drying oven at 60°C for drying to obtain the product Fe3O4@GO@MOF-199.

[0061] The prepared Fe3O4@GO@MOF-199 is applied as perchlorate salt extraction material for treatment of perchlorate salt wastewater, and the application conditions are consistent with those of Example 1. After detection, the adsorption amount of Fe3O4@GO@MOF-199 for perchlorate salt is 50.5 μg / g, the concentration of perchlorate salt in the purified water is 99 μg / L, and the removal rate is only 50.5%, which is not good.

[0062] The above examples are merely examples for clear illustration, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can also be made by those of ordinary skill in the art, and it is not necessary or possible to exhaust all the embodiments, and thus the obvious changes or variations still fall within the protection scope of the present application.

Claims

1. The application of graphene oxide / metal-organic framework modified magnetic nanoparticles as perchlorate extraction materials, characterized in that, The application method is as follows: magnetic nanoparticles Fe3O4@GO@MIL-53(Al)-NH2 modified with graphene oxide / metal-organic framework are added to perchlorate wastewater to extract perchlorate. Then, the used Fe3O4@GO@MIL-53(Al)-NH2 is separated and recovered by magnetic field to obtain purified water. The Fe3O4@GO@MIL-53(Al)-NH2 has a particle size of 5-25 nm and a specific surface area of ​​80-120 m². 2 / g, with an inner diameter of 1-1.3nm, it is a spherical particle with pores formed by combining magnetic Fe3O4 as the core, composite graphene oxide and metal-organic framework material MIL-53(Al)-NH2.

2. The application of the graphene oxide / metal-organic framework modified magnetic nanoparticles according to claim 1 as a perchlorate extraction material, characterized in that, The preparation method of Fe3O4@GO@MIL-53(Al)-NH2 includes the following steps: 1) After dissolving ferric chloride and ferric chloride in water, the mixture is heated to the reaction temperature under a protective atmosphere, and then ammonia water is added dropwise to carry out the reaction, thereby obtaining magnetic nanoparticles Fe3O4. 2) Fe3O4 and 3-aminopropyltrimethoxysilane were dissolved in an aqueous ethanol solution and heated to the reaction temperature under weakly acidic conditions. Then, graphene oxide was added to continue the reaction to obtain graphene oxide-modified magnetic nanoparticles Fe3O4@GO. 3) Fe3O4@GO, aluminum trichloride and 2-aminoterephthalic acid were added to water and ultrasonically dispersed, then heated to react and obtain magnetic nanoparticles Fe3O4@GO@MIL-53(Al)-NH2 modified with graphene oxide / metal-organic framework.

3. The application of the graphene oxide / metal-organic framework modified magnetic nanoparticles according to claim 2 as a perchlorate extraction material, characterized in that, In step 1), the molar ratio of ferric chloride to ferrous chloride is 1:(0.4-0.5), the molar amount of ferric chloride to the volume ratio of ammonia is 1 mol:(20-25) mL, the reaction temperature is 80-90℃, and the reaction time is 10-12 h.

4. The application of the graphene oxide / metal-organic framework modified magnetic nanoparticles according to claim 2 as a perchlorate extraction material, characterized in that, In step 2), the mass ratio of Fe3O4, 3-aminopropyltrimethoxysilane and graphene oxide is 1:(2.5-3.0):(0.5-0.8), the weak acid conditions are pH 4-5, the reaction temperature is 60-70℃, and after reacting for 10-12 hours, graphene oxide is added and the reaction continues for another 10-12 hours.

5. The application of the graphene oxide / metal-organic framework modified magnetic nanoparticles according to claim 2 as a perchlorate extraction material, characterized in that, In step 3), the mass ratio of Fe3O4@GO, aluminum trichloride and 2-aminoterephthalic acid is 1:(0.7-0.8):(0.5-0.6), and the mixture is heated to 150-160℃ for 10-12 hours.

6. The application of the graphene oxide / metal-organic framework modified magnetic nanoparticles according to claim 1 as a perchlorate extraction material, characterized in that, The perchlorate wastewater has a pH of 6-8 and contains one or more of sodium perchlorate, potassium perchlorate, and lithium perchlorate, with a perchlorate concentration of 100-200 μg / L. The dosage of Fe3O4@GO@MIL-53(Al)-NH2 in the perchlorate wastewater is 1-2 g / L, and the removal efficiency for perchlorate is 80-90%.

7. The application of the graphene oxide / metal-organic framework modified magnetic nanoparticles according to claim 1 as a perchlorate extraction material, characterized in that, The extraction temperature was 20-25℃, the extraction time was 2-3 min, and the extraction yield of Fe3O4@GO@MIL-53(Al)-NH2 for perchlorate was 80-90 μg / g.

8. The application of the graphene oxide / metal-organic framework modified magnetic nanoparticles according to claim 1 as a perchlorate extraction material, characterized in that, The used Fe3O4@GO@MIL-53(Al)-NH2 is regenerated by the following method: using potassium chloride aqueous solution as the eluent, the used Fe3O4@GO@MIL-53(Al)-NH2 is added to the eluent, perchlorate is eluted in an ultrasonic cleaner, and then the regenerated Fe3O4@GO@MIL-53(Al)-NH2 is obtained by separation and recovery with the help of magnetic field.

9. The application of the graphene oxide / metal-organic framework modified magnetic nanoparticles according to claim 8 as a perchlorate extraction material, characterized in that, The concentration of the potassium chloride aqueous solution is 10-50 mmol / L, and the elution time is 30-60 min; the extraction amount of perchlorate by the regenerated Fe3O4@GO@MIL-53(Al)-NH2 is more than 80% of that of the unused Fe3O4@GO@MIL-53(Al)-NH2.

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