Acrylic fiber loaded FeMOF material and preparation method and application thereof

Abstract

This invention relates to an acrylic fiber-loaded FeMOF material, its preparation method, and its application. The preparation method involves mixing a FeMOF precursor solution with acrylic fibers containing amide and / or carboxyl groups on their surface, followed by reaction and post-treatment to obtain the acrylic fiber-loaded FeMOF material. The FeMOF precursor solution is prepared by first mixing a ferric salt and DMF and stirring, then adding terephthalic acid and water and continuing stirring to obtain the FeMOF precursor solution. The acrylic fiber-loaded FeMOF material consists of acrylic fibers and irregularly structured FeMOF loaded on them. The application involves using the acrylic fiber-loaded FeMOF material for dye degradation. This invention can reduce the concentration of pollutants in wastewater, has good regenerability, is easy to recycle, and reduces treatment costs.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, and relates to an acrylic fiber-supported FeMOF material, its preparation method, and its application. Background Technology

[0002] In recent years, with the increasingly severe environmental pollution problem, the treatment of dye wastewater has become an urgent environmental challenge. Traditional dye wastewater treatment methods suffer from low efficiency and complex operation, thus seeking a new, efficient, and environmentally friendly treatment technology has become a research focus. Currently, dye wastewater treatment methods include biological, chemical, and physical methods. Fenton oxidation is a typical representative of advanced oxidation technologies in chemical methods, characterized by strong oxidizing power, mild conditions, and high treatment efficiency. The pH of a homogeneous Fenton reaction is typically between 2.0 and 4.0, and under acidic conditions, Fe... 2+ The catalytic decomposition of H2O2 generates a large number of highly oxidizing hydroxyl radicals, which degrade organic pollutants. However, the homogeneous Fenton process has some limitations, such as a high iron requirement during the reaction, the easy generation of large amounts of iron sludge, a narrow applicable pH range, and the potential for secondary pollution. These limitations restrict the application of the homogeneous Fenton reaction in practical industrial wastewater treatment.

[0003] To overcome the aforementioned problems, researchers have developed heterogeneous Fenton catalysts, stabilizing iron (or other transition metals) in the catalyst structure. These catalysts exhibit good catalytic performance, low iron leaching rates, and can extend the pH range of the reaction. Iron oxides, other metal oxides, and MOF (Metal-organic frameworks) series catalysts have all been reported as heterogeneous Fenton catalysts that can replace iron ions in the catalytic degradation of various dye wastewaters. Among them, the MOF series, as a high-performance porous heterogeneous Fenton catalyst, has attracted considerable attention from researchers.

[0004] MOFs possess large specific surface areas, abundant pore structures, and high metal content, making them promising catalysts for advanced oxidation technologies in wastewater treatment. Studies have shown that iron-based MOFs can efficiently adsorb and catalyze the decomposition of harmful substances in dye wastewater, demonstrating significant application potential. MIL-100(Fe) and Fe-II-MIL-100(Fe) are both iron-based MOF materials (FeMOFs); the former is a pure trivalent iron-based MOF, while the latter incorporates Fe... 2+ It can realize Fe 2+ and Fe 3+ The in-situ recycling exhibits strong Fenton catalytic activity.

[0005] However, although iron-based MOFs have great application potential, in practical applications of dye wastewater treatment, MOF catalysts are difficult to separate from the reaction solution for recycling. This is because: (1) MOF materials are structurally fragile and easily damaged by mechanical pressure. Filtration usually requires passing the mixture through a filter membrane or paper, which may cause MOF particles to break or deform, reducing their performance or stability; (2) MOFs are usually small in size, typically in the nanometer to micrometer range. Due to the small particle size and potentially irregular particle shape, it is difficult to effectively separate MOF particles and the liquid phase through filtration. For these two reasons, pure MOF materials are generally not suitable for traditional filtration separation methods, but are better suited for centrifugal separation. In addition, current researchers focus on the preparation of MOF materials, but have not studied the dye removal mechanism of MOF materials. However, in the actual process of dye wastewater treatment, MOF materials have low dyeing and decolorization efficiency and incomplete removal. This is because MOF materials tend to aggregate in wastewater, which greatly reduces their catalytic performance.

[0006] To achieve recycling, the literature (DOI:10.1016 / j.seppur.2021.118620) successfully synthesized Fe3O4@MOF-5, a yolk-shell material with Fe3O4 as the core and MOF as the shell. This material exhibited significantly higher Fenton catalytic efficiency than pure Fe3O4 NP and could be recovered from solution under an external magnetic field. However, the first step in preparing the magnetically recyclable Fe3O4 material required a 10-hour reaction in a high-temperature, high-pressure reactor at 200°C, which consumed a large amount of energy and increased costs. Summary of the Invention

[0007] The purpose of this invention is to solve the problems existing in the prior art and provide an acrylonitrile fiber-supported FeMOF material, its preparation method and application. The aim is to prepare a novel heterogeneous Fenton catalyst acrylonitrile fiber-supported FeMOF material, construct a heterogeneous Fenton system, and achieve excellent decolorization effect on dye wastewater.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A method for preparing FeMOF-loaded acrylonitrile fiber material involves mixing a FeMOF precursor solution with acrylonitrile fibers containing amide groups and / or carboxyl groups on the surface, reacting the mixture, and then post-treating it (washing 10 to 20 times and then vacuum drying at 50 to 70°C for 12 to 24 hours) to obtain the FeMOF-loaded acrylonitrile fiber material.

[0010] The metal ion in the FeMOF precursor is Fe. 3+ The organic ligand is terephthalic acid;

[0011] The solvent in the FeMOF precursor solution is a mixture of DMF and water, with a molar ratio of DMF to water of 20–30:160–170.

[0012] The reaction temperature is 85–95℃ (preferably 90℃), and the reaction time is 5 hours or more.

[0013] This invention loads FeMOF onto the surface of acrylic fibers using an in-situ synthesis method. The specific principle is as follows:

[0014] The surface of acrylic fibers contains functional groups such as amide and carboxyl groups. These functional groups contain nitrogen and oxygen atoms, and these atoms have unbonded lone pairs of electrons that can interact with Fe. 3+ A strong coordination bond is formed between the amide group and Fe. 3+ After the formation of strong coordination bonds, the infrared spectrum shows that the characteristic peak of the amide group increases from 1677 cm⁻¹. -1 Offset to 1665cm -1 Carboxyl group and Fe 3+ After a strong coordination bond is formed, the infrared spectrum shows that the characteristic peak of the carboxyl group increases from 1576 cm⁻¹. -1 The location was shifted to 1600cm. -1 ;

[0015] At the same time, terephthalic acid also reacts with Fe 3+ Strong coordination bonds are formed, and the infrared spectrum shows a value at 540 cm⁻¹. -1 The presence of a strong Fe-O bond characteristic absorption peak indicates that there is a bond between the carboxyl group and the Fe group in terephthalic acid. 3+ Metal-oxygen bonds were formed between them;

[0016] The dual action fixes FeMOF to the fiber surface, forming an irregular FeMOF structure;

[0017] In the traditional solvothermal method for preparing pure MOF, the solvent used is DMF, which can damage the fibers. Therefore, this invention chooses to add water to reduce the solvent concentration. This invention controls the molar ratio of DMF to water to be 20-30:160-170, which can protect the acrylic fibers and allow them to maintain their original crystal structure. Changing the ratio of the two will affect the formation of FeMOF material loaded on the acrylic fibers.

[0018] The reaction temperature should not be too high, otherwise the acrylic fiber will dissolve as the temperature rises, and the acrylic fiber-supported FeMOF material cannot be prepared; the reaction temperature should not be too low either, otherwise FeMOF cannot be formed; the reaction time should not be too short, otherwise FeMOF cannot be formed.

[0019] Existing technologies include in-situ synthesis methods to load catalysts onto fiber surfaces, but their principles differ from this invention, and their effects are not as good. For example, Reference 1 (Preparation of Self-Supported Tin Dioxide / Carbon Composite Flexible Electrode by Electrospinning and its Application in Lithium-Ion Batteries) uses polyvinylpyrrolidone (PVP) as a polymer precursor and stannous chloride dihydrate (SnCl2·H2O) as a raw material. SnO2 / carbon composite nanofiber flexible membranes are generated in situ through electrospinning and pyrolysis carbonization. While the electrospinning fiber preparation technology improves the dispersion, it leads to a large number of metal ions entering the fiber structure, reducing their exposure to active sites on the carrier surface. Reference 2 (DOI:10.1021 / acs.iecr) (7b04202) First, aminoterephthalic acid (ATA) was dissolved in a polymer solution, and then electrospinned to obtain nanofibers containing ATA linkers embedded in the polymer. Then, all samples were immersed in an acetone solution of zirconium chloride (ZrCl4) and ATA and loaded with unmodified polymer materials. However, the unmodified polymer materials are difficult to ensure the stability of MOF composites. Reference 3 (DOI:10.1021 / ja106381x) used in-situ microwave irradiation technology to directly grow MIL-47 crystals on electrospun polyacrylonitrile (PAN) fiber mats. However, MOF crystals are unstable and easily fall off the film, which may lead to stability problems in practical applications of the prepared materials.

[0020] As a preferred technical solution:

[0021] The preparation method of FeMOF material supported on acrylonitrile fiber as described above has a reaction time of 5-7 h (preferably 6 h).

[0022] The preparation method of FeMOF material loaded on acrylonitrile fiber as described above, the preparation process of FeMOF precursor solution is as follows: first, mix ferric salt and DMF, stir for 5 to 15 min (preferably 10 min), then add terephthalic acid and water, and continue stirring for 20 to 40 min (preferably 30 min) to obtain FeMOF precursor solution;

[0023] The FeMOF precursor solution can also be prepared by directly mixing ferric salt, DMF, terephthalic acid and water. However, considering that the ferric salt in the actual experiment is in block form and difficult to disperse and dissolve, this invention selects DMF with strong dissolving properties to disperse and dissolve the ferric salt first, and then adds terephthalic acid and water to it.

[0024] The solvent in the FeMOF precursor solution is a mixture of DMF and water; the solute in the FeMOF precursor solution is ferric salt and terephthalic acid. The role of terephthalic acid is to act as an organic ligand, forming coordinate bonds with iron ions to construct the FeMOF framework structure and increase the stability of the framework.

[0025] In the preparation method of FeMOF material supported on acrylonitrile fiber as described above, the molar ratio of ferric salt, terephthalic acid, and DMF is 1:1:20-30.

[0026] The preparation method of FeMOF material loaded on acrylonitrile fiber as described above uses ferric chloride hexahydrate as the trivalent iron salt.

[0027] The preparation method of FeMOF material loaded on acrylonitrile fiber as described above, wherein the preparation process of acrylonitrile fiber containing amide groups and / or carboxyl groups on the surface is as follows: acrylonitrile fiber is immersed in a sodium hydroxide solution with a concentration of 10-15wt% (preferably 12wt%) and a temperature of 90-95℃ (preferably 95℃) at a bath ratio of 1:5-20 (preferably 1:16-17h) for 10-13min (preferably 10-11min), and then post-treated (first washed to pH=6-8, then dried at 50-70℃ for 10-18h) to obtain acrylonitrile fiber containing amide groups and / or carboxyl groups on the surface;

[0028] This invention prepares acrylic fibers with amide and / or carboxyl groups on their surface using an alkaline hydrolysis method. Acid hydrolysis and pressurized catalytic hydrolysis can also be used. Acid hydrolysis requires excessively high acid concentrations, resulting in high costs and inconvenient operation, and is therefore rarely used. Pressurized hydrolysis requires sophisticated equipment, and its research and practical application benefits are far lower than other hydrolysis methods. Alkaline hydrolysis offers mild reaction conditions, requires no special equipment, and is easy to control; therefore, this invention preferably uses alkaline hydrolysis.

[0029] The preparation method of FeMOF-loaded acrylonitrile fiber as described above involves preparing acrylonitrile fibers with amide groups and / or carboxyl groups on the surface in a dyeing machine with an average rotation speed of 60 r / min.

[0030] The method for preparing FeMOF material loaded with acrylic fibers as described above, wherein the average length of the acrylic fibers is 10-15 cm.

[0031] In the preparation method of FeMOF material loaded on acrylonitrile fibers as described above, the mass ratio of FeMOF precursor solution to acrylonitrile fibers containing amide groups and / or carboxyl groups on the surface is 50:1, which allows the reaction to proceed fully.

[0032] The present invention also provides an acrylonitrile fiber-loaded FeMOF material prepared by a method for preparing an acrylonitrile fiber-loaded FeMOF material as described in any of the preceding claims, which is composed of acrylonitrile fibers and irregularly structured FeMOF loaded thereon.

[0033] The FeMOF structure in the prior art is regular, while the FeMOF structure of the present invention is irregular because of the Fe... 3+ Simultaneously, due to the coordination effect of amide and / or carboxyl groups in acrylic fibers and terephthalic acid, the amide and / or carboxyl groups and terephthalic acid in acrylic fibers influence the Fe... 3+ The coordination of the center is competitive, and different coordinating groups can adopt various different configurations during coordination, leading to the irregularity of MOF. During the construction of FeMOF, defects or doping of the FeMOF structure may occur, which will lead to the irregularity of the MOF. FeMOF with irregular structure has more active sites than FeMOF with regular structure because FeMOF with irregular structure has more uneven surface defects. These structures provide more active sites, allowing more dye molecules and hydrogen peroxide to be adsorbed and degraded on the surface, which is beneficial to improving the reaction rate.

[0034] As a preferred technical solution:

[0035] The FeMOF-loaded acrylic fiber material described above has a FeMOF loading of 5–10 wt% on the acrylic fiber.

[0036] This invention also provides the application of the acrylic fiber-loaded FeMOF material as described above. The acrylic fiber-loaded FeMOF material is used for the degradation of dyes. Taking methylene blue as an example, the specific process is described as follows: First, the acrylic fiber-loaded FeMOF material is added to a methylene blue solution, then hydrogen peroxide solution is added, the pH value of the system is adjusted to 7, and degradation is carried out for 90 minutes. The initial concentration of the methylene blue solution is 15-30 mg / L, and the concentration of the hydrogen peroxide solution is 1-5 mol / L.

[0037] When the FeMOF material loaded on acrylonitrile fibers of the present invention is used for dye degradation, a high dye decolorization efficiency can be obtained. The specific reasons are as follows: ① FeMOF can be better retained in the reaction system by binding with acrylonitrile fibers to avoid FeMOF aggregation; ② There is an adsorption-degradation synergistic effect between acrylonitrile fibers and FeMOF. The modified acrylonitrile fibers have a large number of pores, which means that they have a large surface area available for adsorption. Attaching FeMOF to acrylonitrile fibers can increase the contact area between FeMOF and dye molecules, increase the number of active sites, and allow pollutants to be quickly adsorbed to the active sites and undergo degradation reactions. The synergistic effect of adsorption and degradation improves the catalytic performance of FeMOF, increases the utilization rate of FeMOF, and thus enhances the dyeing decolorization efficiency.

[0038] The principle of this invention is as follows:

[0039] The cyano groups on the macromolecular chains of acrylic fibers (PAN) undergo hydrolysis under the catalysis of alkali to generate amide or carboxyl groups. These functional groups can coordinate with iron ions. FeMOF is loaded onto the surface of acrylic fibers through in-situ synthesis. The Fe(III) on the FeMOF surface undergoes a Fenton-like reaction, catalyzing the decomposition of hydrogen peroxide to generate ·OH free radicals, which then catalyze the degradation of dye molecules.

[0040] Beneficial effects:

[0041] (1) The preparation method of the acrylonitrile fiber supported FeMOF material of the present invention uses the in-situ growth method to prepare acrylonitrile supported FeMOF material. The preparation process is simple and the composite effect is good, which provides a new idea for the preparation of heterogeneous Fenton catalyst iron-based MOF composite materials.

[0042] (2) The acrylonitrile-supported FeMOF material of the present invention has a large specific surface area and abundant pore structure, which enables it to efficiently adsorb dye molecules and hydrogen peroxide molecules and enrich them on the catalyst surface, thereby rapidly enriching them on the material surface, thereby improving the degradation activity and reducing the concentration of pollutants in wastewater.

[0043] (3) This invention uses acrylonitrile fiber as a carrier to combine FeMOF and acrylonitrile to form acrylonitrile fiber supported FeMOF material, giving full play to the advantages of both, solving the problem of easy aggregation of MOF material, enhancing its catalytic effect, developing a cost-effective and resource-sustainable supported catalyst material, and expanding its application in the fields of adsorption and catalysis.

[0044] (4) On the basis of ensuring excellent catalytic performance, the acrylonitrile-supported FeMOF material of the present invention also has good regenerability and is easy to recycle. After simple water washing, it can be recycled and reused multiple times, reducing the processing cost.

[0045] (5) When the FeMOF material loaded on acrylonitrile fiber is used for dye degradation, the present invention can obtain a high dye decolorization efficiency.

[0046] (6) This invention avoids the damage to acrylonitrile fibers caused by high temperature and organic solvents involved in traditional MOF preparation methods. The results of SEM, XRD and FTIR show that the bulk structure of acrylonitrile fibers is completely preserved. Attached Figure Description

[0047] Figure 1 This is a scanning electron microscope image of the FeMOF-loaded acrylic fiber material prepared in Example 1 of the present invention;

[0048] Figure 2 The X-ray diffraction pattern of the FeMOF-loaded acrylonitrile fiber material prepared in Example 1 of this invention;

[0049] Figure 3 The infrared spectrum of the FeMOF-loaded acrylic fiber material prepared in Example 1 of this invention is shown below.

[0050] Figure 4 The graph shows the recycling performance of the FeMOF-loaded acrylic fiber material prepared in Example 3 of this invention in degrading methylene blue. Detailed Implementation

[0051] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0052] The following are the measurement methods for the relevant performance in each embodiment:

[0053] Degradation rate: A standard curve was established. After degradation, the residual concentration of methylene blue aqueous solution at the maximum absorption wavelength was calculated based on the absorbance and the standard curve. The degradation rate was calculated based on the initial concentration and residual concentration of methylene blue aqueous solution.

[0054] Loading capacity: Weigh the fiber mass before and after loading to calculate the loading capacity.

[0055] Example 1

[0056] A method for preparing FeMOF material supported on acrylic fibers, comprising the following steps:

[0057] (1) Preparation of raw materials;

[0058] Ferric salts: Ferric chloride hexahydrate;

[0059] Terephthalic acid;

[0060] DMF;

[0061] water;

[0062] Acrylic fiber: Manufacturer is Hubei Ruziniu Shoes Group Co., Ltd., acrylonitrile content is 86%, and average length is 10cm;

[0063] Sodium hydroxide aqueous solution;

[0064] (2) Preparation of FeMOF precursor solution;

[0065] First, mix 2.7g of ferric salt and 20ml of DMF and stir for 10min. Then add 1.66g of terephthalic acid and 30ml of water and continue stirring for 30min to obtain the FeMOF precursor solution.

[0066] (3) Prepare acrylic fibers containing amide groups and / or carboxyl groups;

[0067] 30.15g of acrylic fiber was placed in a dyeing bottle containing a 12wt% sodium hydroxide aqueous solution at a bath ratio of 1:17. Then it was placed in a dyeing machine with an average rotation speed of 60r / min and the temperature was set to 95℃ and soaked for 10min. After post-treatment, acrylic fiber with amide groups and / or carboxyl groups on the surface was obtained.

[0068] (4) A FeMOF precursor solution with a mass ratio of 50:1 was mixed with acrylic fibers containing amide groups and / or carboxyl groups on their surface. The mixture was then reacted at 90°C for 6 hours in a reaction vessel lined with polytetrafluoroethylene. After post-treatment, FeMOF was successfully loaded onto the fiber surface, thus obtaining the acrylic fiber-loaded FeMOF material. Figure 2 As shown, PAN A (PAN stands for acrylic fiber; PAN with a subscript A indicates alkali-treated acrylic fiber.) There is a strong peak at 2θ = 17°, which is due to PAN. A Caused by (100) diffraction of a hexahedral lattice; PAN A @Fe(BDC)(DMF) (represents fiber material loaded with FeMOF, where Fe(BDC)(DMF) is FeMOF) and PAN A The presence of similar characteristic peaks indicates that the modified fiber still retains the original crystal structure of acrylic fiber. However, the weakened absorption peak intensity suggests that only a partial change in the fiber's crystal phase occurred. After loading, PAN... ANew diffraction peaks appeared at 9.2° and 11.0° in the @Fe(BDC)(DMF) spectrum, which are similar to the characteristic diffraction peaks of Fe(BDC)(DMF), but the peak intensities are weaker, indicating a lower Fe(BDC)(DMF) loading; in addition, PAN A The broad diffraction peaks of Fe(BDC)(DMF) in the 15°–20° range may be due to the overlap between the characteristic diffraction peaks of Fe(BDC)(DMF) and the characteristic diffraction peaks of PAN fibers.

[0069] The electron microscope image of the final acrylonitrile fiber-supported FeMOF material is shown below. Figure 1 As shown, the FeMOF loading on its acrylic fiber is 6.1 wt%. Infrared spectroscopy tests were performed on it, as shown... Figure 3 As shown, both FeMOF-loaded and FeMOF-loaded acrylic fibers exhibit two distinct absorption peaks at 2940 cm⁻¹. -1 and 2243cm -1 These absorption peaks correspond to the stretching vibrations of the nitrile (C≡N) and methylene (-CH2) groups on the acrylic fiber, respectively; the characteristic peak of the amide group of the loaded PAN increases from 1677 cm⁻¹. -1 Offset to 1665cm -1 The characteristic peak of the carboxyl group starts from 1576 cm⁻¹ -1 The location was shifted to 1600cm. -1 The reason for this change is that the amide and carboxyl groups have a strong chelating coordination with the Fe ion center in FeMOF, and this interaction leads to a shift in the absorption wavelength; affected by the absorption peak of the FeMOF carboxyl-COO symmetric stretching vibration, PAN... A The -CH bending vibration absorption peak is at 1357 cm⁻¹ -1 Moved to 1389cm -1 At 750cm -1 The obvious absorption peak at 540 cm⁻¹ is attributed to the CH bending vibration peak of the benzene ring in FeMOF. -1 The presence of a strong Fe-O bond characteristic absorption peak indicates the formation of a metal-oxygen bond between the carboxyl group of terephthalic acid and Fe(III); Figure 3 It can be seen that the nitrile and methylene groups did not disappear, but the strength was reduced. This indicates that the modification technology of the present invention maintains the integrity of the original fiber structure, and only loads FeMOF on its surface and in the pores. Therefore, it effectively avoids the damage to the fiber structure caused by the traditional solvothermal method of MOF preparation.

[0070] The FeMOF material loaded with acrylic fiber prepared above was used to degrade methylene blue. The specific process was as follows: at 25°C, 0.1 g of the FeMOF material loaded with acrylic fiber was first added to 25 ml of methylene blue aqueous solution with an initial concentration of 20 mg / L and an initial pH of 7. Then, 5 ml of hydrogen peroxide aqueous solution with a concentration of 4 mol / L was added to adjust the pH of the system to 7. The degradation was carried out for 90 min, and the final degradation rate of methylene blue was measured to be 59.12%.

[0071] Comparative Example 1

[0072] A method for preparing FeMOF material loaded with acrylonitrile fiber is basically the same as in Example 1, except that the amount of water added in step (2) is 20 ml.

[0073] Due to the small proportion of water, it is impossible to prepare FeMOF materials supported on acrylic fibers.

[0074] Comparing Comparative Example 1 and Example 1, it can be seen that the proportion of water in the molar ratio of DMF to water in Comparative Example 1 is too small, which makes it impossible to prepare FeMOF material supported on acrylonitrile fibers. This is because DMF will dissolve acrylonitrile fibers.

[0075] Comparative Example 2

[0076] A method for preparing FeMOF material loaded with acrylonitrile fiber is basically the same as in Example 1, except that the amount of water added in step (2) is 40 ml.

[0077] Because the proportion of water in step (2) is too large, it is impossible to prepare FeMOF material supported on acrylonitrile fibers.

[0078] Comparing Comparative Example 2 and Example 1, it can be seen that the proportion of water in the molar ratio of DMF to water in Comparative Example 2 is too large, which makes it impossible to prepare FeMOF material supported on acrylonitrile fibers. This is because MOF formation is more difficult in a solvent with a high proportion of water.

[0079] Example 2

[0080] A method for preparing FeMOF material supported on acrylic fibers, comprising the following steps:

[0081] (1) Preparation of raw materials;

[0082] Ferric salts: Ferric chloride hexahydrate;

[0083] Terephthalic acid;

[0084] DMF;

[0085] water;

[0086] Acrylic fiber: Manufacturer is Hubei Ruziniu Shoes Group Co., Ltd., acrylonitrile content is 86%, and average length is 11.9cm;

[0087] Sodium hydroxide aqueous solution;

[0088] (2) Preparation of FeMOF precursor solution;

[0089] First, mix 5.4g of ferric salt and 40ml of DMF and stir for 10min. Then add 3.32g of terephthalic acid and 60ml of water and continue stirring for 30min to obtain the FeMOF precursor solution.

[0090] (3) Prepare acrylic fibers containing amide groups and / or carboxyl groups;

[0091] 15.25g of acrylic fiber was placed in a dyeing bottle containing a 12wt% sodium hydroxide aqueous solution at a bath ratio of 1:16. Then it was placed in a dyeing machine with an average rotation speed of 60r / min and the temperature was set to 95℃ for 11min. After post-treatment, acrylic fiber with amide groups and / or carboxyl groups on the surface was obtained.

[0092] (4) After mixing FeMOF precursor solution with a mass ratio of 50:1 with acrylic fibers containing amide groups and / or carboxyl groups on the surface, the mixture is reacted at 90°C for 6 hours in a reaction vessel with a polytetrafluoroethylene liner. After post-treatment, the acrylic fiber-loaded FeMOF material is obtained.

[0093] The final FeMOF loading on the acrylic fiber of the prepared FeMOF-loaded material was 6.4 wt%.

[0094] The FeMOF material loaded with acrylic fiber prepared above was used to degrade methylene blue. The specific process was as follows: at 25°C, 0.2 g of FeMOF material loaded with acrylic fiber was first added to 25 ml of methylene blue aqueous solution with an initial concentration of 20 mg / L and an initial pH of 7. Then, 5 ml of hydrogen peroxide aqueous solution with a concentration of 4 mol / L was added to adjust the pH of the system to 7. The degradation was carried out for 90 min, and the final degradation rate of methylene blue was measured to be 90.1%.

[0095] Example 3

[0096] A method for preparing FeMOF material supported on acrylic fibers, comprising the following steps:

[0097] (1) Preparation of raw materials;

[0098] Ferric salts: Ferric chloride hexahydrate;

[0099] Terephthalic acid;

[0100] DMF;

[0101] water;

[0102] Acrylic fiber: Manufacturer is Hubei Ruziniu Shoes Group Co., Ltd., acrylonitrile content is 86%, and average length is 12.04cm;

[0103] Sodium hydroxide aqueous solution;

[0104] (2) Preparation of FeMOF precursor solution;

[0105] First, mix 2.72g of ferric salt and 20ml of DMF and stir for 10min. Then add 1.67g of terephthalic acid and 30ml of water and continue stirring for 30min to obtain the FeMOF precursor solution.

[0106] (3) Prepare acrylic fibers containing amide groups and / or carboxyl groups;

[0107] 3g of acrylic fiber was placed in a dyeing bottle containing a 12wt% sodium hydroxide aqueous solution at a bath ratio of 1:17. Then it was placed in a dyeing machine with an average rotation speed of 60r / min and the temperature was set to 95℃ for 11min. After post-treatment, acrylic fiber with amide groups and / or carboxyl groups on the surface was obtained.

[0108] (4) After mixing FeMOF precursor solution with a mass ratio of 50:1 with acrylic fibers containing amide groups and / or carboxyl groups on the surface, the mixture is reacted at 90°C for 6 hours in a reaction vessel with a polytetrafluoroethylene liner. After post-treatment, the acrylic fiber-loaded FeMOF material is obtained.

[0109] The final FeMOF loading on the acrylic fiber of the prepared acrylic fiber-supported FeMOF material was 6.5 wt%.

[0110] The FeMOF-loaded acrylic fiber material prepared above was used to degrade methylene blue. The specific process was as follows: At 25°C, 0.3 g of the FeMOF-loaded acrylic fiber material was first added to 25 ml of an aqueous solution of methylene blue with an initial concentration of 20 mg / L and an initial pH of 7. Then, 5 ml of an aqueous solution of hydrogen peroxide with a concentration of 4 mol / L was added to adjust the pH of the system to 7. Degradation was carried out for 90 min. Figure 4 It can be seen that the degradation rate of methylene blue in the initial degradation test was 94.50%. As the number of uses increased, the degradation rate of the dye gradually decreased. By the fourth cycle of reuse test, the degradation rate of methylene blue dropped to 77.58%.

[0111] Example 4

[0112] A method for preparing FeMOF material supported on acrylic fibers, comprising the following steps:

[0113] (1) Preparation of raw materials;

[0114] Ferric salts: Ferric chloride hexahydrate;

[0115] Terephthalic acid;

[0116] DMF;

[0117] water;

[0118] Acrylic fiber: Manufacturer is Hubei Ruziniu Shoes Group Co., Ltd., acrylonitrile content is 86%, and average length is 12cm;

[0119] Sodium hydroxide aqueous solution;

[0120] (2) Preparation of FeMOF precursor solution;

[0121] First, mix 2.75g of ferric salt and 20ml of DMF and stir for 10min. Then add 1.65g of terephthalic acid and 30ml of water and continue stirring for 30min to obtain the FeMOF precursor solution.

[0122] (3) Prepare acrylic fibers containing amide groups and / or carboxyl groups;

[0123] 11.98g of acrylic fiber was placed in a dyeing bottle containing a 12wt% sodium hydroxide aqueous solution at a bath ratio of 1:17. Then it was placed in a dyeing machine with an average rotation speed of 60r / min and the temperature was set to 95℃ for 11min. After post-treatment, acrylic fiber with amide groups and / or carboxyl groups on the surface was obtained.

[0124] (4) After mixing FeMOF precursor solution with a mass ratio of 50:1 with acrylic fibers containing amide groups and / or carboxyl groups on the surface, the mixture is reacted at 90°C for 6 hours in a reaction vessel with a polytetrafluoroethylene liner. After post-treatment, the acrylic fiber-loaded FeMOF material is obtained.

[0125] The final FeMOF loading on the acrylic fiber of the prepared acrylic fiber-supported FeMOF material was 7.2 wt%.

[0126] The FeMOF material loaded with acrylic fiber prepared above was used to degrade methylene blue. The specific process was as follows: at 25°C, 0.4 g of FeMOF material loaded with acrylic fiber was first added to 25 ml of methylene blue aqueous solution with an initial concentration of 20 mg / L and an initial pH of 7. Then, 5 ml of hydrogen peroxide aqueous solution with a concentration of 4 mol / L was added to adjust the pH of the system to 7. The degradation was carried out for 90 min, and the final degradation rate of methylene blue was measured to be 97.47%.

[0127] Example 5

[0128] A method for preparing FeMOF material supported on acrylic fibers, comprising the following steps:

[0129] (1) Preparation of raw materials;

[0130] Ferric salts: Ferric chloride hexahydrate;

[0131] Terephthalic acid;

[0132] DMF;

[0133] water;

[0134] Acrylic fiber: Manufacturer is Hubei Ruziniu Shoes Group Co., Ltd., acrylonitrile content is 86%, and average length is 15cm;

[0135] Sodium hydroxide aqueous solution;

[0136] (2) Preparation of FeMOF precursor solution;

[0137] First, mix 5.42g of ferric salt and 40ml of DMF and stir for 10min. Then add 3.35g of terephthalic acid and 60ml of water and continue stirring for 30min to obtain the FeMOF precursor solution.

[0138] (3) Prepare acrylic fibers containing amide groups and / or carboxyl groups;

[0139] 6g of acrylic fiber was placed in a dyeing bottle containing a 12wt% sodium hydroxide aqueous solution at a bath ratio of 1:17. Then it was placed in a dyeing machine with an average rotation speed of 60r / min and the temperature was set to 95℃ for 11min. After post-treatment, acrylic fiber with amide groups and / or carboxyl groups on the surface was obtained.

[0140] (4) After mixing FeMOF precursor solution with a mass ratio of 50:1 with acrylic fibers containing amide groups and / or carboxyl groups on the surface, the mixture is reacted at 90°C for 6 hours in a reaction vessel with a polytetrafluoroethylene liner. After post-treatment, the acrylic fiber-loaded FeMOF material is obtained.

[0141] The final FeMOF loading on the acrylic fiber of the prepared acrylic fiber material was 5.9 wt%.

[0142] The FeMOF material loaded with acrylic fiber prepared above was used to degrade methylene blue. The specific process was as follows: at 25°C, 0.5 g of FeMOF material loaded with acrylic fiber was first added to 25 ml of methylene blue aqueous solution with an initial concentration of 20 mg / L and an initial pH of 7. Then, 5 ml of hydrogen peroxide aqueous solution with a concentration of 4 mol / L was added to adjust the pH of the system to 7. The degradation was carried out for 90 min, and the final degradation rate of methylene blue was measured to be 97.61%.

Claims

1. A method for preparing FeMOF material supported on acrylic fibers, characterized in that, FeMOF precursor solution is mixed with acrylic fibers containing amide groups and / or carboxyl groups on the surface and reacted. After post-treatment, acrylic fiber-loaded FeMOF material is obtained. The metal ion in the FeMOF precursor is Fe. 3+ The organic ligand is terephthalic acid; The solvent in the FeMOF precursor solution is a mixture of DMF and water, with a molar ratio of DMF to water of 20~30:160~170; The reaction temperature is 85~95℃, and the reaction time is more than 5 hours; The preparation process of acrylic fibers with amide groups and / or carboxyl groups on the surface is as follows: acrylic fibers are immersed in a sodium hydroxide solution with a concentration of 10-15 wt% and a temperature of 90-95℃ at a bath ratio of 1:5-20 for 10-13 minutes. After post-treatment, acrylic fibers with amide groups and / or carboxyl groups on the surface are obtained.

2. The method for preparing an acrylonitrile fiber-supported FeMOF material according to claim 1, characterized in that, The preparation process of FeMOF precursor solution is as follows: First, mix ferric salt and DMF, stir for 5-15 minutes, then add terephthalic acid and water, and continue stirring for 20-40 minutes to obtain FeMOF precursor solution.

3. The method for preparing an acrylic fiber-supported FeMOF material according to claim 2, characterized in that, The molar ratio of ferric salt, terephthalic acid, and DMF is 1:1:20~30.

4. The method for preparing an acrylonitrile fiber-supported FeMOF material according to claim 2, characterized in that, The trivalent ferric salt is ferric chloride hexahydrate.

5. The method for preparing an acrylic fiber-supported FeMOF material according to claim 1, characterized in that, The preparation process of acrylic fibers with amide groups and / or carboxyl groups on the surface is carried out in a dyeing machine with an average rotation speed of 60 r / min.

6. The method for preparing an acrylic fiber-supported FeMOF material according to claim 1, characterized in that, The mass ratio of FeMOF precursor solution to acrylic fibers with amide and / or carboxyl groups on the surface is 50:

1.

7. An acrylic fiber-loaded FeMOF material prepared by the method for preparing an acrylic fiber-loaded FeMOF material according to any one of claims 1 to 6, characterized in that, It consists of acrylic fibers and irregularly structured FeMOF loaded on them.

8. The acrylic fiber-supported FeMOF material according to claim 7, characterized in that, The loading of FeMOF on acrylic fibers is 5~10wt%.

9. The application of the acrylic fiber-supported FeMOF material as described in claim 7 or 8, characterized in that, Acrylic fibers loaded with FeMOF materials are used for dye degradation.

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