Preparation method and application of an iron-based cyclodextrin MOF loaded graphene oxide catalytic membrane

Abstract

The application relates to a preparation method and application of an iron-based cyclodextrin MOF loaded graphene oxide catalytic membrane, and belongs to the technical field of two-dimensional material membrane preparation. Method: I. preparing a FeCD-MOF@GO solution; II. centrifuging, taking supernatant, and self-assembling the supernatant on a microporous polyether sulfone membrane through a vacuum suction filtration mode, and obtaining an iron-based cyclodextrin MOF loaded graphene oxide catalytic membrane after heat fixing. Application: the catalytic membrane is combined with an oxidant to treat water bodies containing organic pollutants. In the application, the FeCD-MOF is uniformly distributed on the layers of the graphene surface as an intercalation material, a winding water channel is created, the FeCD-MOF is facilitated to fully contact pollutants in water, and the water quality is ensured to be improved; the effective working pH range is widened (from acid to neutral); through an adsorption buffer mechanism, the problem of unstable water quality in the production process caused by raw water quality fluctuation and uneven diffusion of the oxidant is reduced. The application is suitable for treating water bodies containing organic pollutants.

Description

Technical Field

[0001] This invention belongs to the field of two-dimensional material membrane preparation technology, specifically relating to a method for preparing and applying a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF. Background Technology

[0002] In recent years, with increasing public concern for water environmental safety, advanced oxidation technologies have played a crucial role in water pollution control. Fenton oxidation, as a highly efficient advanced oxidation process, degrades pollutants in water through hydroxyl radicals generated from Fe2+ / Fe3+ and hydrogen peroxide. Although Fenton oxidation technology has achieved significant results in water treatment, the short lifespan, rapid quenching tendency, and pH sensitivity of hydroxyl radicals limit its widespread application and make it difficult to address sudden fluctuations in water quality.

[0003] To overcome these challenges, cyclodextrins, with their unique structure of a hydrophilic outer wall and a hydrophobic inner cavity, have attracted widespread attention in environmental science, energy, materials science, and life sciences. This special structure gives cyclodextrins excellent dispersibility and high adsorption capacity in aqueous phases, enabling them to rapidly encapsulate pollutants and iron ions, increasing the concentration of pollutants in localized areas. This spatial proximity accelerates the reaction between free radicals and pollutants, effectively reducing the quenching of hydroxyl radicals. This process, known as confined reaction, significantly improves the degradation efficiency of pollutants.

[0004] On the other hand, two-dimensional membrane materials based on graphene oxide, characterized by their layered stacking structure, can prolong the movement path of liquid or gas molecules within the membrane, enhancing the residence time of substances. In water treatment applications, this characteristic increases the contact and residence time of pollutants in the catalytic membrane, allowing for full interaction between pollutants and the graphene oxide layers and the active substances they support, thus enhancing pollutant removal efficiency. Therefore, the rational design of two-dimensional channels is crucial for improving the performance of catalytic membranes and is of great significance for the effective treatment of micro-pollutants in water. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that Fenton catalytic membranes are constrained by pH conditions and have difficulty coping with sudden fluctuations in water quality, and to provide a method for preparing and applying a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF.

[0006] A method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF comprises the following steps:

[0007] I. Preparation of iron-based cyclodextrin MOF-supported graphene oxide solution:

[0008] A solution of ferric nitrate nonahydrate and γ-cyclodextrin in N,N-dimethylformamide was mixed with an aqueous solution of graphene oxide to obtain a mixed solution, which was then placed in a reaction vessel. A methanol diffusion reaction was then carried out, and hexadecyltrimethylammonium bromide was added to the mixed solution and stirred to obtain a FeCD-MOF@GO solution.

[0009] II. Preparation of iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane:

[0010] The FeCD-MOF@GO solution was centrifuged, and the supernatant was then taken and self-assembled onto a microporous polyethersulfone membrane by vacuum filtration. After heat fixation, an iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane was obtained, thus completing the preparation method.

[0011] Furthermore, the mass-to-volume ratio of the aqueous solution of ferric nitrate nonahydrate, γ-cyclodextrin, N,N-dimethylformamide, and graphene oxide in step one is (0.74–0.75) g:(0.2–0.4) g:(40–60) mL:(100–300) mL.

[0012] Furthermore, in step one, the mass-to-volume ratio of graphene oxide to deionized water in the aqueous solution of graphene oxide is (0.01–0.03) g:(100–300) mL.

[0013] Furthermore, the methanol diffusion reaction described in step one involves placing a reaction vessel containing the mixed solution in a glass methanol diffusion apparatus at 25°C in a saturated methanol vapor environment for 40–45 hours. The surface area of ​​the reaction vessel receiving the methanol vapor is 16.58 cm². 2 .

[0014] Furthermore, in step one, the mass-to-volume ratio of the mixed solution to hexadecyltrimethylammonium bromide is 20 mL: 0.16 g.

[0015] Furthermore, the stirring time described in step one is 3 hours.

[0016] Furthermore, the centrifugation described in step two involves centrifuging at 3000 r / min for 5 min to obtain a pale yellow supernatant.

[0017] Furthermore, the vacuum filtration method described in step two is used to self-assemble the membrane onto the microporous polyethersulfone membrane: the pore size of the microporous polyethersulfone membrane is 0.1 μm, the vacuum filtration pressure is 0.08–0.1 MPa, and the effective membrane area filtered onto the microporous polyethersulfone membrane is 12.56 cm². 2 The total mass of FeCD-MOF and graphene oxide is 0.1g, and the mass ratio of graphene oxide to FeCD-MOF is 1:(10~35).

[0018] Furthermore, the heat-fixing temperature in step two is 70°C, and the heat-fixing time is 4 hours.

[0019] Application of the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared above: After the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane is combined with an oxidant, it can filter and treat water containing organic pollutants at a certain flux.

[0020] The organic pollutants are bisphenol A, atrazine, tetracycline, ciprofloxacin, sulfamethoxazole, metronidazole, carbamazepine, or phenol.

[0021] The oxidant is hydrogen peroxide;

[0022] The flux is 30–150 L·m -2 ·h -1 .

[0023] This invention prepares a two-dimensional Fenton catalytic membrane based on an iron-based cyclodextrin MOF supporting graphene oxide. Compared to traditional two-dimensional membranes, this membrane exhibits more stable and efficient performance, effectively adsorbing, retaining, and degrading micro-pollutants in water, and is easily applicable in practice. This invention combines Fenton catalysis with membrane separation technology for treating wastewater containing micro-pollutants. The two-dimensional catalytic membrane, prepared by self-assembling an iron-based cyclodextrin MOF supporting graphene oxide on a microporous polyethersulfone substrate, is a previously unreported method and has broad application prospects in water quality safety.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] (1) The raw materials used in this invention are readily available and inexpensive, do not require inert gas protection (all preparation processes are carried out in an air atmosphere), have low synthesis temperature, and the production equipment, process conditions and steps are relatively simple. Furthermore, the composition of the composite membrane is easy to adjust, making it suitable for industrial production.

[0026] (2) Compared with the previously reported heterogeneous Fenton reaction system, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane has a wider effective pH operating range (pH 3-7) and a broader application space.

[0027] (3) Compared with the previously reported two-dimensional catalytic membranes, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane has a high specific surface area. FeCD-MOF is distributed on the graphene oxide sheets as an intercalation material, and a tortuous two-dimensional channel is constructed within the graphene oxide framework. This promotes the effective contact between FeCD-MOF and trace pollutants in water, thereby enhancing the effect of Fenton catalysis.

[0028] (4) This invention introduces cyclodextrin into the catalytic membrane, which can rapidly and effectively adsorb trace pollutants in water. On the one hand, based on the principle of increasing substrate concentration, it improves catalytic efficiency. On the other hand, it mitigates the problem of unstable water quality during production caused by fluctuations in raw water quality and uneven diffusion of oxidant through a buffering mechanism.

[0029] (5) On the one hand, FeCD-MOF can expand the transport channels of graphene oxide membrane and accelerate the passage of molecules in the membrane; on the other hand, the stable intercalation can also improve the mechanical strength of the membrane structure and ensure the stability of the water channels.

[0030] This invention inserts iron-based cyclodextrin (FeCD-MOF) between graphene oxide nanosheets via vacuum-assisted self-assembly, resulting in a stable layered structure and providing tortuous water channels, thus ensuring improved water quality. The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared by this invention solves the problem of Fenton catalytic membranes being constrained by pH conditions and unable to cope with sudden water quality fluctuations; it broadens the effective working pH range (from acidic to neutral); and through an adsorption buffering mechanism, it mitigates the unstable water quality during production caused by fluctuations in the original water quality and uneven diffusion of the oxidant.

[0031] The total thickness of the iron-based cyclodextrin MOF-supported graphene oxide catalytic film prepared in this invention is 1.961–3.247 μm.

[0032] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane in this invention is suitable for treating water bodies containing organic pollutants. Attached Figure Description

[0033] Figure 1 The images shown are scanning electron microscope planar and cross-sectional views of the graphene oxide catalytic membranes supported on iron-based cyclodextrin MOFs in Examples 1-3 after vacuum-assisted self-assembly.

[0034] Figure 2 The iron-based cyclodextrin MOF-supported graphene oxide catalytic membranes used in Examples 1-3 were applied at 90 L·m⁻¹. -2 ·h -1 The graph shows the removal efficiency of a bisphenol A aqueous solution containing 3 mM hydrogen peroxide and 10 mg / L bisphenol A through continuous filtration for 2 hours at a certain flux; where ■ represents Example 1, ● represents Example 2, and ▲ represents Example 3.

[0035] Figure 3 The graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF in Example 2 was used in the range of 30–150 L·m⁻¹. -2 ·h -1 The graph shows the removal efficiency of a 3 mM hydrogen peroxide and a 10 mg / L bisphenol A aqueous solution through continuous filtration for 72 hours at a certain flux; where ■ represents 30 L·m-2 ·h -1 ● indicates 60 L·m -2 ·h -1 ★ indicates 90 L·m -2 ·h -1 ▼ indicates 120 L·m -2 ·h -1 ◆ indicates 150 L·m -2 ·h -1 ;

[0036] Figure 4 The graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF in Example 2 was used in the range of 30–150 L·m⁻¹. -2 ·h -1 The graph shows the removal efficiency of a 10 mg / L bisphenol A aqueous solution through continuous filtration for 72 hours at a certain flux; where ■ represents 30 L·m -2 ·h -1 ● indicates 60 L·m -2 ·h -1 ★ indicates 90 L·m -2 ·h -1 ▼ indicates 120 L·m -2 ·h -1 ◆ indicates 150 L·m -2 ·h -1 ;

[0037] Figure 5 The graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF in Example 2 was used at 90 L·m -2 ·h -1 The removal efficiency of continuous filtration of aqueous solutions containing 3 mM hydrogen peroxide and 10 mg / L bisphenol A for 40 min, 20 min, and 60 min at a certain flux is shown in the figure.

[0038] Figure 6 The graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF in Example 2 was used at 90 L·m -2 ·h -1 The removal efficiency of continuous filtration of aqueous solutions containing 3 mM hydrogen peroxide and 10 mg / L bisphenol A for 40 min, 20 min, and 60 min at the same flux is shown in the graph.

[0039] Figure 7 In Example 2, the graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF was tested at different pH ranges at 90 L·m⁻¹. -2 ·h -1The graph shows the removal efficiency of a solution containing 3 mM hydrogen peroxide and 10 mg / L bisphenol A for 72 hours of continuous filtration at a certain flux; where ■ indicates pH 3, ● indicates pH 5, ▲ indicates pH 7, and ▼ indicates pH 9.

[0040] Figure 8 The graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF in Example 2 was used at 90 L·m -2 ·h -1 The graph shows the removal efficiency of 0.6 mM hydrogen peroxide and 2 mg / L bisphenol A (BPA), atrazine (ATZ), tetracycline (Tc), ciprofloxacin (CIP), sulfamethoxazole (SMX), metronidazole (MNZ), carbamazepine (CBZ), and phenol (PhOH) aqueous solutions after continuous filtration for 2 hours at a certain flux. Detailed Implementation

[0041] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

[0042] Specific Implementation Method 1: This implementation method describes a method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF, which is carried out according to the following steps:

[0043] I. Preparation of iron-based cyclodextrin MOF-supported graphene oxide solution:

[0044] A solution of ferric nitrate nonahydrate and γ-cyclodextrin in N,N-dimethylformamide was mixed with an aqueous solution of graphene oxide to obtain a mixed solution, which was then placed in a reaction vessel. A methanol diffusion reaction was then carried out, and hexadecyltrimethylammonium bromide was added to the mixed solution and stirred to obtain a FeCD-MOF@GO solution.

[0045] II. Preparation of iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane:

[0046] The FeCD-MOF@GO solution was centrifuged, and the supernatant was then taken and self-assembled onto a microporous polyethersulfone membrane by vacuum filtration. After heat fixation, an iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane was obtained, thus completing the preparation method.

[0047] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the mass-to-volume ratio of the ferric nitrate nonahydrate, γ-cyclodextrin, N,N-dimethylformamide solution, and graphene oxide aqueous solution in step one is (0.74–0.75) g:(0.2–0.4) g:(40–60) mL:(100–300) mL. Other steps and parameters are the same as in Specific Implementation Method One.

[0048] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 in that the mass-to-volume ratio of graphene oxide to deionized water in the aqueous solution of graphene oxide in step 1 is (0.01–0.03) g:(100–300) mL. Other steps and parameters are the same as in Specific Implementation Method 1.

[0049] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the methanol diffusion reaction in step one is as follows: In a glass methanol diffusion device, a reaction vessel containing the mixed solution is placed in a saturated methanol vapor environment at 25°C and reacted for 40–45 hours. The surface area of ​​the reaction vessel receiving methanol vapor is 16.58 cm². 2 The other steps and parameters are the same as in Specific Implementation Method 1.

[0050] Specific Implementation Method 5: This implementation method differs from Specific Implementation Method 1 in that the mass-to-volume ratio of the mixed solution to hexadecyltrimethylammonium bromide in step one is 20 mL: 0.16 g. Other steps and parameters are the same as in Specific Implementation Method 1.

[0051] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that the stirring time in step one is 3 hours. Other steps and parameters are the same as in Specific Implementation Method One.

[0052] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that the centrifugation in step two is performed by centrifuging at 3000 r / min for 5 min to obtain a pale yellow supernatant. Other steps and parameters are the same as in Specific Implementation Method One.

[0053] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that the vacuum filtration method described in step two is used to self-assemble the membrane onto the microporous polyethersulfone membrane: the pore size of the microporous polyethersulfone membrane is 0.1 μm, the vacuum filtration pressure is 0.08–0.1 MPa, and the effective membrane area filtered onto the microporous polyethersulfone membrane is 12.56 cm². 2 The total mass of FeCD-MOF and graphene oxide is 0.1g, wherein the mass ratio of graphene oxide to FeCD-MOF is 1:(10-35). Other steps and parameters are the same as in Specific Implementation Method 1.

[0054] In this embodiment, FeCD-MOF and graphene oxide are the solutes in the FeCD-MOF@GO solution.

[0055] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that the heat-fixing temperature in step two is 70°C, and the heat-fixing time is 4 hours. Other steps and parameters are the same as in Specific Implementation Method One.

[0056] Specific Implementation Method 10: This implementation method describes an application of a graphene oxide catalytic membrane supported by iron-based cyclodextrin MOF: After the graphene oxide catalytic membrane supported by iron-based cyclodextrin MOF is combined with an oxidant, it filters and treats water containing organic pollutants at a certain flux.

[0057] The organic pollutants are bisphenol A, atrazine, tetracycline, ciprofloxacin, sulfamethoxazole, metronidazole, carbamazepine, or phenol.

[0058] The oxidant is hydrogen peroxide;

[0059] The flux is 30–150 L·m -2 ·h -1 .

[0060] The beneficial effects of the present invention are verified through the following embodiments:

[0061] Example 1:

[0062] A method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF comprises the following steps:

[0063] I. Preparation of iron-based cyclodextrin MOF-supported graphene oxide solution:

[0064] A solution of ferric nitrate nonahydrate (Fe(NO3)3·9H2O) and γ-cyclodextrin (γ-CD) in N,N-dimethylformamide was mixed with an aqueous solution of graphene oxide (GO) to obtain a mixed solution, which was then placed in a reaction vessel. A methanol diffusion reaction was then carried out. Hexadecyltrimethylammonium bromide was then added to the mixed solution and stirred to obtain a FeCD-MOF@GO solution.

[0065] II. Preparation of iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane:

[0066] The FeCD-MOF@GO solution was centrifuged, and the supernatant was then taken and self-assembled onto a microporous polyethersulfone membrane by vacuum filtration. After heat fixation, an iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane was obtained, thus completing the preparation method.

[0067] In step one of this embodiment, the mass-to-volume ratio of ferric nitrate nonahydrate, γ-cyclodextrin, N,N-dimethylformamide solution, and graphene oxide aqueous solution is 0.7476 g: 0.3 g: 50 mL: 200 mL.

[0068] In step one of this embodiment, the mass-to-volume ratio of graphene oxide to deionized water in the aqueous solution of graphene oxide is 0.02 g: 200 mL.

[0069] The methanol diffusion reaction described in step one of this embodiment involves placing a reaction vessel containing the mixed solution in a glass methanol diffusion apparatus at 25°C in a saturated methanol vapor environment for 40–45 hours. The surface area of ​​the reaction vessel receiving methanol vapor is 16.58 cm². 2 In step one of this embodiment, the mass-to-volume ratio of the mixed solution to hexadecyltrimethylammonium bromide is 20 mL: 0.16 g.

[0070] The stirring time in step one of this embodiment is 3 hours.

[0071] In step two of this embodiment, centrifugation is performed at a speed of 3000 r / min for 5 min to obtain a pale yellow supernatant.

[0072] In step two of this embodiment, the vacuum filtration method is used to self-assemble the membrane onto the microporous polyethersulfone membrane: the pore size of the microporous polyethersulfone membrane is 0.1 μm, the vacuum filtration pressure is 0.08–0.1 MPa, and the effective membrane area filtered onto the microporous polyethersulfone membrane is 12.56 cm². 2 The total mass of FeCD-MOF and graphene oxide is 0.1g, and the mass ratio of graphene oxide to FeCD-MOF is 1:10.

[0073] In step two of this embodiment, the temperature for heat curing is 70°C and the heat curing time is 4 hours.

[0074] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane obtained in this embodiment is denoted as FeCD-MOF@GO-10.

[0075] Example 2:

[0076] In step two of this embodiment, the mass ratio of graphene oxide to FeCD-MOF is 1:20; the rest is the same as in embodiment 1.

[0077] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane obtained in this embodiment is denoted as FeCD-MOF@GO-20.

[0078] Example 3:

[0079] In step two of this embodiment, the mass ratio of graphene oxide to FeCD-MOF is 1:30; the rest is the same as in embodiment 1.

[0080] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane obtained in this embodiment is denoted as FeCD-MOF@GO-30.

[0081] like Figure 1As shown, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 1 can obtain a typical two-dimensional layered membrane morphology after vacuum-assisted self-assembly, with a membrane thickness of approximately 1.961 μm.

[0082] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2 can achieve a typical two-dimensional layered membrane morphology after vacuum-assisted self-assembly, with a membrane thickness of approximately 2.072 μm.

[0083] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 3 can achieve a typical two-dimensional layered membrane morphology after vacuum-assisted self-assembly, with a membrane thickness of approximately 3.247 μm.

[0084] like Figure 2 As shown, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 1, at 90 L·m -2 ·h -1 The removal efficiency of a 3mM hydrogen peroxide and a 10mg / L bisphenol A aqueous solution was obtained by continuous filtration for 2 hours at a certain flux. The removal rate was stable at 94.07%.

[0085] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 90 L·m -2 ·h -1 The removal efficiency of a 3mM hydrogen peroxide and a 10mg / L bisphenol A aqueous solution was obtained by continuous filtration for 2 hours at a certain flux. The removal rate was stable at 97.43%.

[0086] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 3, at 90 L·m -2 ·h -1 The removal efficiency of a 3 mM hydrogen peroxide and a 10 mg / L bisphenol A aqueous solution was obtained by continuous filtration for 2 hours at a certain flux. The removal rate was stable at 96.22%.

[0087] like Figure 3 As shown, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 30 L·m -2 ·h -1 The removal efficiency of a 3mM hydrogen peroxide and a 10mg / L bisphenol A aqueous solution was obtained by continuous filtration for 72 hours at a certain flux. The removal rate was stable at 99.79%.

[0088] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 60 L·m -2 ·h -1The removal efficiency of a 3 mM hydrogen peroxide and a 10 mg / L bisphenol A aqueous solution was continuously filtered for 72 hours at a certain flux, and the removal rate was stable at 98.50%.

[0089] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 90 L·m -2 ·h -1 The removal efficiency of a 3 mM hydrogen peroxide and 10 mg / L bisphenol A aqueous solution was continuously filtered for 72 hours at a certain flux, and the removal rate remained stable at 97.81%.

[0090] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 120 L·m -2 ·h -1 The removal efficiency of a 3mM hydrogen peroxide and 10mg / L bisphenol A aqueous solution was continuously filtered for 72 hours at a certain flux. The removal rate was stable at 96.98% from 0 to 2400 min and at 89.88% from 2400 to 4320 min.

[0091] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 150 L·m -2 ·h -1 The removal efficiency of a 3mM hydrogen peroxide and 10mg / L bisphenol A aqueous solution was continuously filtered for 72 hours at a certain flux. The removal rate was stable at 96.34% from 0 to 1200 min and at 83.30% from 1200 to 4320 min.

[0092] like Figure 4 As shown, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 30 L·m -2 ·h -1 The removal efficiency of bisphenol A aqueous solution containing 10 mg / L was obtained by continuous filtration for 72 hours at a certain flux. The removal rate was stable at 97.66% from 0 to 2160 min and at 39.08% from 2160 to 4320 min.

[0093] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 60 L·m -2 ·h -1 The removal efficiency of bisphenol A aqueous solution containing 10 mg / L was obtained by continuous filtration for 72 hours at a certain flux. The removal rate was stable at 92.26% from 0 to 1080 min and at 37.69% from 1080 to 4320 min.

[0094] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 90 L·m -2 ·h -1The removal efficiency of bisphenol A aqueous solution containing 10 mg / L was obtained by continuous filtration for 72 hours at a certain flux. The removal rate was stable at 89.29% from 0 to 720 min and at 36.89% from 720 to 4320 min.

[0095] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 120 L·m -2 ·h -1 The removal efficiency of bisphenol A aqueous solution containing 10 mg / L was obtained by continuous filtration for 72 hours at a certain flux. The removal rate was stable at 87.01% from 0 to 480 min and at 35.84% from 480 to 4320 min.

[0096] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 150 L·m -2 ·h -1 The removal efficiency of bisphenol A aqueous solution containing 10 mg / L was obtained by continuous filtration for 72 hours at a certain flux. The removal rate was stable at 85.31% from 0 to 420 min and at 35.15% from 420 to 4320 min.

[0097] like Figure 5 As shown, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at 90 L·m -2 ·h -1 The removal efficiency of continuous filtration at a certain flux for 40 min containing 3 mM hydrogen peroxide and 10 mg / L bisphenol A aqueous solution, 20 min containing 3 mM hydrogen peroxide and 30 mg / L bisphenol A aqueous solution, and 60 min containing 3 mM hydrogen peroxide and 10 mg / L bisphenol A aqueous solution was shown in the graph. The removal rate was stable at 97.43% from 0 to 40 min, 94.89% from 40 to 60 min, and 97.44% from 60 to 120 min.

[0098] Figure 6 The graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF in Example 2 was used at 90 L·m -2 ·h -1 The removal efficiency of continuous filtration at a certain flux for 40 min containing 3 mM hydrogen peroxide and 10 mg / L bisphenol A aqueous solution, 20 min containing 10 mg / L bisphenol A aqueous solution, and 60 min containing 3 mM hydrogen peroxide and 10 mg / L bisphenol A aqueous solution was shown in the graph. The removal rate was stable at 97.42% from 0 to 40 min, 89.68% from 40 to 60 min, and 97.40% from 60 to 120 min.

[0099] like Figure 7As shown, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at pH 3 and a flux of 90 L·m⁻¹, exhibits good performance. -2 ·h -1 The removal efficiency of 3mM hydrogen peroxide and 10mg / L bisphenol A aqueous solution was continuously filtered for 72 hours under the condition, and the removal rate was stable at 98.50%.

[0100] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at pH 5 and flux of 90 L·m⁻¹, showed good performance. -2 ·h -1 The removal efficiency of 3mM hydrogen peroxide and 10mg / L bisphenol A aqueous solution was continuously filtered for 72 hours under the condition, and the removal rate was stable at 98.20%.

[0101] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at pH 7 and flux of 90 L·m⁻¹, showed excellent performance. -2 ·h -1 The removal efficiency of 3mM hydrogen peroxide and 10mg / L bisphenol A aqueous solution was measured by continuous filtration for 72 hours under the specified conditions. The removal rate remained stable at 97.81%.

[0102] The iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in Example 2, at pH 9 and flux of 90 L·m⁻¹, showed excellent performance. -2 ·h -1 The removal efficiency of 3mM hydrogen peroxide and 10mg / L bisphenol A aqueous solution was continuously filtered for 72 hours under the condition of continuous filtration. The removal rate was stable at 97.66% from 0 to 3120 min and at 96.30% from 3120 to 4320 min.

[0103] like Figure 8 As shown, in Example 2, the graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF was used at 90 L·m⁻¹. -2 ·h -1 At a certain flux, the removal efficiency of aqueous solutions containing 0.6 mM hydrogen peroxide and 2 mg / L bisphenol A (BPA), atrazine (ATZ), tetracycline (Tc), ciprofloxacin (CIP), sulfamethoxazole (SMX), metronidazole (MNZ), carbamazepine (CBZ), and phenol (PhOH) was continuously filtered for 2 hours. The removal rates were stable at 99.43%, 99.35%, 98.95%, 99.33%, 99.13%, 99.28%, 99.53%, and 99.73%, respectively.

[0104] In summary, the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared in this embodiment exhibits high and stable performance. It can be prepared through the self-assembly of two-dimensional graphene oxide nanosheets and FeCD-MOF. The performance of the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane can be controlled by the mass ratio of two-dimensional graphene oxide nanosheets to FeCD-MOF. When the mass ratio of two-dimensional graphene oxide nanosheets to FeCD-MOF is 1:20, the overall performance of the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane is optimal.

[0105] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many modifications under the guidance of the present invention without departing from the spirit of the present invention, and these modifications are all within the protection scope of the present invention.

Claims

1. A method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF, characterized in that... It proceeds in the following steps: I. Preparation of iron-based cyclodextrin MOF-supported graphene oxide solution: A solution of ferric nitrate nonahydrate and γ-cyclodextrin in N,N-dimethylformamide was mixed with an aqueous solution of graphene oxide to obtain a mixed solution, which was then placed in a reaction vessel. A methanol diffusion reaction was then carried out, and hexadecyltrimethylammonium bromide was added to the mixed solution and stirred to obtain a FeCD-MOF@GO solution. II. Preparation of iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane: The FeCD-MOF@GO solution was centrifuged, and the supernatant was then taken and self-assembled onto a microporous polyethersulfone membrane by vacuum filtration. After heat fixation, an iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane was obtained, thus completing the preparation method. In step one, the methanol diffusion reaction involves placing a reaction vessel containing the mixed solution in a glass methanol diffusion apparatus at 25°C in a saturated methanol vapor environment for 40-45 hours. The surface area of ​​the reaction vessel receiving the methanol vapor is 16.58 cm². 2 .

2. The method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF according to claim 1, characterized in that... The mass-to-volume ratio of the aqueous solution of ferric nitrate nonahydrate, γ-cyclodextrin, N,N-dimethylformamide, and graphene oxide in step one is (0.74~0.75)g:(0.2~0.4)g:(40~60)mL:(100~300)mL.

3. The method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF according to claim 1, characterized in that... In step one, the mass-to-volume ratio of graphene oxide to deionized water in the aqueous solution of graphene oxide is (0.01~0.03) g:(100~300) mL.

4. The method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF according to claim 1, characterized in that... In step one, the mass-to-volume ratio of the mixed solution to hexadecyltrimethylammonium bromide is 20 mL: 0.16 g.

5. The method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF according to claim 1, characterized in that... The stirring time mentioned in step one is 3 hours.

6. The method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF according to claim 1, characterized in that... Centrifugation as described in step two: Centrifuge at 3000 r / min for 5 min to obtain a pale yellow supernatant.

7. The method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF according to claim 1, characterized in that... The vacuum filtration method described in step two is used to self-assemble the membrane onto the microporous polyethersulfone membrane: the pore size of the microporous polyethersulfone membrane is 0.1 μm, the vacuum filtration pressure is 0.08~0.1 MPa, and the effective membrane area filtered onto the microporous polyethersulfone membrane is 12.56 cm². 2 The total mass of FeCD-MOF and graphene oxide is 0.1g, and the mass ratio of graphene oxide to FeCD-MOF is 1:(10~35).

8. The method for preparing a graphene oxide catalytic membrane supported on an iron-based cyclodextrin MOF according to claim 1, characterized in that... The heat-fixing temperature in step two is 70℃, and the heat-fixing time is 4 hours.

9. The application of the iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane prepared by the method described in claim 1, characterized in that... Based on the combination of iron-based cyclodextrin MOF-supported graphene oxide catalytic membrane and oxidant, water containing organic pollutants is filtered and treated at a certain flux. The organic pollutants are bisphenol A, atrazine, tetracycline, ciprofloxacin, sulfamethoxazole, metronidazole, carbamazepine, or phenol. The oxidant is hydrogen peroxide; The flux is 30~150 L·m -2 ·h -1 .

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