Novel heterostructure catalytic separation composite membrane as well as preparation method and application thereof

Abstract

According to the novel heterostructure catalytic separation composite membrane and the preparation method and application thereof, a hydrophilic polymer containing hydroxyl, amino and carboxyl can efficiently adsorb and enrich specific pollutants through hydrogen bonds or electrostatic interaction, and the specific pollutants can be efficiently separated by combining the Fenton-like or catalytic oxidation effect of a metal catalyst loaded on a two-dimensional nanosheet. Organic matters enriched or intercepted on the surface of the membrane can be effectively degraded under high-flux operation; the in-situ degradation capability of the catalyst-loaded two-dimensional nanosheets on pollutants endows the membrane with an excellent self-cleaning function, pollutants adsorbed on the surface of the membrane can be decomposed in time, and membrane pollution is remarkably reduced. The service life of the membrane is greatly prolonged, the treatment efficiency in the long-term operation process is guaranteed, the maintenance and operation cost is reduced, and the membrane has huge application potential and market value in the field of advanced treatment of refractory industrial wastewater such as printing and dyeing, pharmacy and the like.

Description

Technical Field

[0001] This invention relates to the field of composite membrane technology for water pollution purification, and in particular to a novel heterogeneous catalytic separation composite membrane, its preparation method, and its application. Background Technology

[0002] Currently, water scarcity has become a pressing global crisis, exacerbated by increasingly severe water pollution. Against this backdrop, finding efficient wastewater treatment methods is crucial for alleviating water scarcity, and membrane separation, with its advantages of high separation efficiency, low energy consumption, and no secondary pollution, has become a widely used and important technology in the water treatment field. However, pollutants in water, such as dyes and antibiotics, possess complex compositions, stable structures, and high biotoxicity, making them difficult to effectively degrade and remove using traditional methods.

[0003] In the field of existing membrane separation technology, common membranes such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis membranes have each played a certain role, but all have significant shortcomings. For example, Chinese patent application CN115106105A discloses a ternary heterojunction photocatalytic membrane, which loads BiOBr / Bi2MoO6@MXene photocatalytic material onto a PES substrate through vacuum-assisted self-assembly for the treatment of antibiotic wastewater. Although this technology alleviates membrane fouling to some extent by introducing photocatalytic function, the construction of its catalytic and separation layers relies on multi-step synthesis and filtration assembly, making the process relatively complex. Furthermore, the membrane material mainly relies on photocatalytic degradation, and the flux and rejection rate still need to be improved when treating high-concentration or complex wastewater. Specifically, although microfiltration membranes can intercept larger particles, their relatively large pore size results in insufficient removal capacity for small molecule pollutants, and they are prone to clogging during use, leading to a rapid decline in membrane flux. While ultrafiltration membranes can retain some large organic molecules, their effectiveness in treating small molecule pollutants (such as some antibiotics) is unsatisfactory, and membrane fouling remains a prominent issue. Frequent cleaning not only increases costs but also affects treatment efficiency. Nanofiltration membranes are effective in removing divalent and multivalent ions, removing some small organic molecules and providing a softening effect, but they require high operating pressures, increasing treatment costs. Their ability to remove monovalent ions is limited, and they are also susceptible to organic fouling. Even reverse osmosis membranes, which offer relatively good removal efficiency, face challenges such as large permeate pressure differentials and high energy consumption, which limits their large-scale application. Furthermore, existing modified or composite membranes often have limited functionality, making it difficult to simultaneously achieve high-efficiency separation and pollutant degradation at high flux levels. Their insufficient anti-fouling and self-cleaning properties also shorten membrane lifespan and increase treatment costs.

[0004] Therefore, in view of the problems of single function, easy fouling, and difficulty in achieving both flux and removal efficiency in existing membrane materials, the development of an asymmetric multifunctional heterogeneous composite membrane that integrates separation, catalysis and adsorption functions to achieve efficient and stable treatment of recalcitrant organic matter in wastewater has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a novel heterostructure catalytic separation composite membrane, its preparation method, and its application, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: This invention provides a method for preparing a novel heterostructure catalytic separation composite membrane, comprising the following steps: S1. Preparation of two-dimensional sheet catalyst loaded with metal ions: Two-dimensional sheet material, metal salt solution and surfactant are added to deionized water and stirred evenly. After adjusting the pH value, the mixture is transferred to a hydrothermal reactor for hydrothermal reaction. The reaction product is centrifuged, washed and dried to obtain two-dimensional sheet catalyst loaded with metal ions. S2. Preparation of heterogeneous structure catalytic separation composite membrane: The polymer material, solvent and hydrophilic polymer are mixed, heated and stirred, and then a mixed solution containing the two-dimensional sheet catalyst and solvent obtained in step S1 is added. The mixture is heated and stirred again, and after degassing treatment, a casting solution is prepared. The casting solution is coated on a substrate, and a film is formed by non-solvent-induced phase transformation to obtain a novel heterogeneous structure catalytic separation composite membrane.

[0007] Preferably, the two-dimensional sheet material in step S1 is selected from one of two-dimensional graphene oxide, molybdenum disulfide, or boron nitride; the sheet size of the two-dimensional sheet material is 1-5 μm and the thickness is 0.3-2 nm.

[0008] Preferably, the metal salt solution in step S1 is selected from ferrous chloride, ferrous sulfate, palladium chloride, chloroplatinic acid, silver nitrate, or copper nitrate; the mass ratio of the two-dimensional sheet material to the metal salt in the metal salt solution is 1:1-1.5; the surfactant is selected from polyvinylpyrrolidone, sodium dodecyl sulfate, or hexadecyltrimethylammonium bromide; the acid used to adjust the pH value is acetic acid or nitric acid, and the adjusted pH value is 5-8.

[0009] Preferably, the hydrothermal reaction temperature in step S1 is 150-220℃, and the reaction time is 6-18h; the centrifugal cleaning speed is 5000-12000r / min, and the drying temperature is 40-60℃.

[0010] Preferably, the weight parts of each component of the reaction product in step S1 are: 0.5-2 parts of two-dimensional sheet material, 0.5-10 parts of metal salt solution, 0.01-0.05 parts of surfactant, and 60-100 parts of deionized water.

[0011] Preferably, the polymer material in step S2 is selected from polysulfone, polyethersulfone, polyvinylidene fluoride, cellulose acetate, or polyacrylonitrile; the hydrophilic polymer is selected from hydroxypropyl cellulose, polylysine, polyaspartic acid, polyamino acid, or chitosan with amino, carboxyl, or hydroxyl groups; and the solvent is selected from dimethylformamide, dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone.

[0012] Preferably, the weight parts of each component in the casting solution prepared in step S2 are: 8-16 parts of polymer material, 77-88 parts of solvent, 1-3 parts of hydrophilic polymer, and 1-3 parts of two-dimensional sheet catalyst; the two-dimensional sheet catalyst is added in the form of a mixed solution containing it, the mixed solution being composed of the two-dimensional sheet catalyst and solvent, and its total weight parts are 3-5 parts.

[0013] Preferably, the heating and stirring temperature in step S2 is 60°C; the substrate is a non-woven fabric; and the non-solvent used in the non-solvent induction method is water.

[0014] The present invention also provides a novel heterostructure catalytic separation composite membrane prepared by a novel method for preparing a heterostructure catalytic separation composite membrane.

[0015] This invention also provides an application of a novel heterogeneous catalytic separation composite membrane in the field of wastewater treatment, wherein the pollutants in the wastewater include any one or a combination of two or more of methylene blue, orange-yellow, methyl violet, norfloxacin, enrofloxacin, and levofloxacin.

[0016] The present invention achieves the following beneficial technical effects compared to the prior art: This invention provides a novel heterogeneous catalytic separation composite membrane, its preparation method, and its applications. The membrane is prepared in one step using a solvent-inducing phase inversion method by blending a two-dimensional sheet-like catalyst loaded with metal ions, a hydrophilic polymer, and a polymer matrix. This results in a heterogeneous structure that combines physical sieving, chemical catalysis, and specific adsorption functions. The hydrophilic polymer, containing hydroxyl, amino, and carboxyl groups, can efficiently adsorb and enrich specific pollutants through hydrogen bonding or electrostatic interactions. Combined with the Fenton-like or catalytic oxidation effects of the metal catalyst supported on the two-dimensional nanosheets, it can effectively degrade organic matter enriched or retained on the membrane surface under high-throughput operation. Furthermore, the in-situ degradation capability of the catalyst-supported two-dimensional nanosheets endows the membrane with excellent self-cleaning properties, promptly decomposing pollutants adsorbed on the membrane surface and significantly reducing membrane fouling. This not only greatly extends the membrane's service life but also ensures treatment efficiency during long-term operation, reducing maintenance and operating costs. It demonstrates enormous application potential and market value in the deep treatment of recalcitrant industrial wastewater from industries such as dyeing and pharmaceutical manufacturing. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a novel heterogeneous catalytic separation composite membrane according to the present invention.

[0019] Figure reference numerals: 1-Two-dimensional sheet material with catalyst supported, 2-Catalyst, 3-Composite membrane layer, 4-Hydrophilic polymer, 5-Nonwoven fabric support layer. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The purpose of this invention is to provide a novel heterostructure catalytic separation composite membrane, its preparation method, and its application, in order to solve the problems existing in the prior art.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Definitions of abbreviations and key terms: PVP (polyvinylpyrrolidone K30), SDS (sodium dodecyl sulfate), CTAB (hexadecyltrimethylammonium bromide), DMF (dimethylformamide), DMAc (dimethylacetamide), DMSO (dimethyl sulfoxide), NMP (N-methylpyrrolidone).

[0024] Example 1 (1) Preparation of two-dimensional sheet materials with metal catalysts supported by hydrothermal method. 0.5 parts of two-dimensional graphene oxide (sheet size 1-5 micrometers, thickness 0.3-2 nanometers), 0.5 parts of ferrous chloride, and 0.01 parts of polyvinylpyrrolidone (K30) were added to 60 parts of deionized water and stirred evenly. Acetic acid was added to adjust the pH of the solution to 5 and stirring was continued for 20 min. After mixing evenly, the solution was transferred to a hydrothermal reactor and hydrothermally reacted at 200°C for 12 hours. The reaction product was washed 5 times by centrifugation with deionized water at 10000 r / min and vacuum dried at 45°C for 24 hours to obtain two-dimensional sheet catalysts with iron ions supported.

[0025] (2) Preparation of heterogeneous catalytic separation composite membrane. 14 parts by weight of polysulfone polymer, 86 parts by weight of DMF solvent, and 2 parts by weight of hydroxypropyl cellulose were added to a three-necked flask and heated and stirred at 60°C for 11 hours. Then, 4 parts by weight of a mixed solution containing 2 parts by weight of the two-dimensional sheet catalyst prepared in step (1) and DMF were added, and the mixture was heated and stirred at 60°C for another 2 hours. After sealing and allowing to stand to remove bubbles, a casting solution was prepared. The casting solution was then coated onto a nonwoven fabric substrate, and a film was formed using a non-solvent-induced phase inversion method with aqueous phase as the non-solvent, thus obtaining the catalytic separation composite membrane.

[0026] (3) Performance testing. The heterostructured catalytic separation composite membrane prepared in this embodiment was tested and found to have a flux of 189 L·m⁻¹ for a mixture of 10 ppm methylene blue and 0.1 mol / L H₂O₂ at 1 bar pressure. -2 h -1 The degradation rate of methylene blue was 97.89%.

[0027] The novel heterostructure catalytic separation composite membrane prepared in Example 1 is as follows: Figure 1 As shown, it includes a nonwoven fabric support layer 5, on which a composite membrane layer 3 is laminated. The composite membrane layer 3 contains a two-dimensional sheet material 1 loaded with a catalyst, a catalyst 2, and a hydrophilic polymer 4.

[0028] Example 2 (1) Preparation of two-dimensional sheet-like materials with metal catalysts supported by hydrothermal method. 0.7 parts of molybdenum disulfide, 2.5 parts of ferrous sulfate, and 0.02 parts of sodium dodecyl sulfate were added to 80 parts of deionized water and stirred evenly. Nitric acid was added to adjust the pH of the solution to 7 and stirring was continued for 50 min. After mixing evenly, the mixture was transferred to a hydrothermal reactor and hydrothermally reacted at 220°C for 8 hours. The reaction product was washed 5 times by centrifugation with deionized water at 6500 r / min and vacuum dried at 55°C for 24 hours to obtain two-dimensional sheet-like catalysts with iron ions supported.

[0029] (2) Preparation of heterogeneous catalytic separation composite membrane. 12 parts by weight of polyethersulfone polymer, 82 parts by weight of DMAc solvent, and 3 parts by weight of polylysine were added to a three-necked flask and heated and stirred at 60°C for 12 hours. Then, 3 parts by weight of a mixed solution containing 1 part by weight of the two-dimensional sheet catalyst prepared in step (1) and DMAc were added, and the mixture was heated and stirred at 60°C for another 2 hours. After sealing and allowing to stand to remove bubbles, a casting solution was prepared. The casting solution was then coated onto a nonwoven fabric substrate, and a film was formed using a non-solvent-induced phase inversion method with aqueous phase as the non-solvent, thus obtaining the catalytic separation composite membrane.

[0030] (3) Performance testing. The heterostructured catalytic separation composite membrane prepared in this embodiment was tested and found to have a flux of 210 L·m⁻¹ for a mixture of 10 ppm orange-yellow and 0.1 mol / L H₂O₂ at 1 bar pressure. -2 h -1 The degradation rate of orange-yellow was 94.54%.

[0031] Example 3 (1) Preparation of two-dimensional sheet-like materials with supported metal catalysts by hydrothermal method. 1 part boron nitride, 4 parts palladium chloride, and 0.03 parts hexadecyltrimethylammonium bromide were added to 70 parts deionized water and stirred evenly. Acetic acid was added to adjust the pH of the solution to 6, and stirring was continued for 30 min. After mixing evenly, the mixture was transferred to a hydrothermal reactor and hydrothermally reacted at 170 °C for 6 hours. The reaction product was washed 5 times by centrifugation with deionized water at 5000 r / min and vacuum dried at 50 °C for 24 hours to obtain a two-dimensional sheet-like catalyst with supported palladium ions.

[0032] (2) Preparation of heterogeneous catalytic separation composite membrane. 10 parts by weight of polyvinylidene fluoride polymer, 84 parts by weight of DMSO solvent, and 2 parts by weight of polyaspartic acid were added to a three-necked flask and heated and stirred at 60°C for 8 hours. Then, 5 parts by weight of a mixed solution containing 3 parts by weight of the two-dimensional sheet catalyst prepared in step (1) and DMSO were added, and the mixture was heated and stirred at 60°C for another 2 hours. After sealing and allowing to stand to remove bubbles, a casting solution was prepared. The casting solution was then coated onto a nonwoven fabric substrate, and a film was formed using a non-solvent-induced phase inversion method with aqueous phase as the non-solvent, thus obtaining the catalytic separation composite membrane.

[0033] (3) Performance testing. The heterostructured catalytic separation composite membrane prepared in this embodiment was tested and found to have a flux of 223 L·m⁻¹ for a mixture of 10 ppm methyl violet and 0.1 mol / L H₂O₂ at 1 bar pressure. -2 h -1 The degradation rate of methyl violet was 94.65%.

[0034] Example 4 (1) Preparation of two-dimensional sheet materials with metal catalysts supported by hydrothermal method. 1.3 parts of two-dimensional graphene oxide, 6 parts of chloroplatinic acid, and 0.04 parts of polyvinylpyrrolidone (K30) were added to 90 parts of deionized water and stirred evenly. Nitric acid was added to adjust the pH of the solution to 5 and stirring was continued for 10 min. After mixing evenly, the mixture was transferred to a hydrothermal reactor and hydrothermally reacted at 160°C for 18 hours. The reaction product was washed 5 times by centrifugation with deionized water at 12000 r / min and vacuum dried at 40°C for 24 hours to obtain two-dimensional sheet catalysts with platinum ions supported.

[0035] (2) Preparation of heterogeneous catalytic separation composite membrane. 16 parts by weight of polyacrylonitrile polymer, 77 parts by weight of DMAc solvent, and 1 part by weight of polyamino acid were added to a three-necked flask and heated and stirred at 60°C for 7 hours. Then, 3 parts by weight of a mixed solution containing 2 parts by weight of the two-dimensional sheet catalyst and DMAc prepared in step (1) were added, and the mixture was heated and stirred at 60°C for another 2 hours. After sealing and allowing to stand to remove bubbles, a casting solution was prepared. The casting solution was then coated onto a nonwoven fabric substrate, and a film was formed using a non-solvent-induced phase inversion method with aqueous phase as the non-solvent, thus obtaining the catalytic separation composite membrane.

[0036] (3) Performance testing. The heterostructured catalytic separation composite membrane prepared in this embodiment was tested and found to have a flux of 188 L·m⁻¹ for a mixture of 10 ppm norfloxacin and 0.1 mol / L H₂O₂ at 1 bar pressure. -2 h -1 Norfloxacin has a degradation rate of 97.67%.

[0037] Example 5 (1) Preparation of two-dimensional sheet material supported on metal catalyst by hydrothermal method. 1.6 parts of molybdenum disulfide, 8 parts of silver nitrate, and 0.03 parts of sodium dodecyl sulfate were added to 80 parts of deionized water and stirred evenly. Acetic acid was added to adjust the pH of the solution to 8 and stirring was continued for 60 min. After mixing evenly, the mixture was transferred to a hydrothermal reactor and hydrothermally reacted at 190 °C for 14 hours. The reaction product was washed 5 times by centrifugation with deionized water at 9000 r / min and vacuum dried at 60 °C for 24 hours to obtain two-dimensional sheet catalyst supported on silver ions.

[0038] (2) Preparation of heterogeneous catalytic separation composite membrane. Eight parts by weight of polyethersulfone polymer, 80 parts by weight of NMP solvent, and three parts by weight of chitosan were added to a three-necked flask and heated and stirred at 60°C for 6 hours. Then, four parts by weight of a mixed solution containing three parts by weight of the two-dimensional sheet catalyst prepared in step (1) and NMP were added, and the mixture was heated and stirred at 60°C for another 2 hours. After sealing and allowing to stand to remove bubbles, a casting solution was prepared. The casting solution was then coated onto a nonwoven fabric substrate, and a film was formed using a non-solvent-induced phase inversion method with aqueous phase as the non-solvent, thus obtaining the catalytic separation composite membrane.

[0039] (3) Performance testing. The heterostructured catalytic separation composite membrane prepared in this embodiment was tested and found to have a flux of 198 L·m⁻¹ for a mixture of 10 ppm enrofloxacin and 0.1 mol / L H₂O₂ at 1 bar pressure. -2 h -1 The degradation rate of enrofloxacin was 98.23%.

[0040] Example 6 (1) Preparation of two-dimensional sheet-like materials with supported metal catalysts by hydrothermal method. 2 parts boron nitride, 10 parts copper nitrate, and 0.05 parts hexadecyltrimethylammonium bromide were added to 100 parts deionized water and stirred evenly. Nitric acid was added to adjust the pH of the solution to 7 and stirring was continued for 40 min. After mixing evenly, the mixture was transferred to a hydrothermal reactor and hydrothermally reacted at 150 °C for 10 hours. The reaction product was washed 5 times by centrifugation with deionized water at 8000 r / min and vacuum dried at 60 °C for 24 hours to obtain a two-dimensional sheet-like catalyst with supported copper ions.

[0041] (2) Preparation of heterogeneous catalytic separation composite membrane. Nine parts by weight of polysulfone polymer material, 88 parts by weight of DMF solvent, and 2 parts by weight of polyaspartic acid were added to a three-necked flask and heated and stirred at 60°C for 9 hours. Then, 5 parts by weight of a mixed solution containing 1 part by weight of the two-dimensional sheet catalyst prepared in step (1) and DMF were added, and the mixture was heated and stirred at 60°C for another 2 hours. After sealing and allowing to stand to remove bubbles, a casting solution was prepared. The casting solution was then coated onto a non-woven fabric substrate, and a film was formed using a non-solvent-induced phase inversion method with aqueous phase as the non-solvent, thus obtaining the catalytic separation composite membrane.

[0042] (3) Performance testing. The heterostructured catalytic separation composite membrane prepared in this embodiment was tested and found to have a flux of 204 L·m⁻¹ for a mixture of 10 ppm levofloxacin and 0.1 mol / L H₂O₂ at 1 bar pressure. -2 h -1 The degradation rate of levofloxacin was 97.67%.

[0043] Comparative Example 1 To demonstrate the inventiveness of this invention, a comparative example is provided here for comparison with Example 1, which does not include a two-dimensional sheet catalyst.

[0044] (1) The casting solution was prepared according to step (2) in Example 1, except that no two-dimensional sheet catalyst was added. Specifically, 14 parts by weight of polysulfone polymer material, 88 parts by weight of DMF solvent and 2 parts by weight of hydroxypropyl cellulose were added to a three-necked flask, heated and stirred at 60°C for 13 hours, and then sealed and allowed to stand to remove bubbles to prepare the casting solution.

[0045] (2) The casting solution was coated onto the nonwoven fabric substrate in the same manner as in Example 1, and a film was prepared by non-solvent-induced phase inversion method.

[0046] (3) Performance test: The test results of the mixture of 10 ppm methylene blue and 0.1 mol / L H2O2 at 1 bar pressure showed that the flux of the membrane was 156 L·m -2 h -1 The degradation rate of methylene blue was only 15.32%. This indicates that the pure polymer membrane without added catalyst mainly relies on physical retention and a small amount of adsorption, and its ability to degrade pollutants is extremely low, far lower than the 97.89% in Example 1.

[0047] Comparative Example 2 To illustrate the role of hydrophilic polymers in this invention, a comparative example is provided here for comparison with Example 1, which does not contain hydrophilic polymers.

[0048] (1) Prepare two-dimensional sheet catalysts loaded with iron ions by the same method as step (1) in Example 1.

[0049] (2) Preparation of casting solution: 14 parts by weight of polysulfone polymer material, 88 parts by weight of DMF solvent, and 4 parts by weight of a mixed solution containing 2 parts by weight of two-dimensional sheet catalyst and DMF prepared in step (1) are added to a three-necked flask. The mixture is heated and stirred at 60°C for 13 hours. After sealing and standing to remove bubbles, the casting solution is prepared.

[0050] (3) The casting solution was coated onto the nonwoven fabric substrate in the same manner as in Example 1, and a film was prepared by non-solvent-induced phase inversion method.

[0051] (4) Performance test: The test results of the mixture of 10 ppm methylene blue and 0.1 mol / L H2O2 at 1 bar pressure showed that the flux of the membrane was 172 L·m -2 h -1 The degradation rate of methylene blue was 68.45%. This indicates that without the addition of hydrophilic polymers, the hydrophilicity of the membrane and its ability to adsorb and enrich pollutants decreased, resulting in a final degradation efficiency significantly lower than the 97.89% in Example 1.

[0052] Test Example: Overall Performance Comparison The overall performance of Embodiments 1-6 of the present invention was compared with that of Comparative Examples 1-2, and the results are shown in the table below.

[0053]

[0054] in conclusion: As can be seen from the table above, the heterostructured catalytic separation composite membranes prepared in Examples 1-6 of this invention all exhibit high flux (>188 L·m⁻¹) when treating wastewater containing different dyes or antibiotics. -2 h -1 The membrane exhibits high flux and high degradation rate (>94%). In contrast, the degradation rates of Comparative Example 1 (without catalyst) and Comparative Example 2 (without hydrophilic polymer) were significantly lower than those of the Example, fully demonstrating that the synergistic effect of the two-dimensional sheet catalyst and hydrophilic polymer in this invention is key to achieving high membrane flux and high degradation efficiency, reflecting the advanced nature and excellent effect of the technical solution of this invention.

[0055] The technical features of the above embodiments provided by the present invention can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] It should be noted that the components mentioned in the above embodiments are all general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0057] This invention has used specific examples to illustrate its principles and implementation methods. The above descriptions of the embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for preparing a novel heterostructured catalytic separation composite membrane, characterized in that, Includes the following steps: S1. Preparation of two-dimensional sheet catalyst loaded with metal ions: Two-dimensional sheet material, metal salt solution and surfactant are added to deionized water and stirred evenly. After adjusting the pH value, the mixture is transferred to a hydrothermal reactor for hydrothermal reaction. The reaction product is centrifuged, washed and dried to obtain two-dimensional sheet catalyst loaded with metal ions. S2. Preparation of heterogeneous structure catalytic separation composite membrane: The polymer material, solvent and hydrophilic polymer are mixed, heated and stirred, and then a mixed solution containing the two-dimensional sheet catalyst and solvent obtained in step S1 is added. The mixture is heated and stirred again, and after degassing treatment, a casting solution is prepared. The casting solution is coated on a substrate, and a film is formed by non-solvent-induced phase transformation to obtain a novel heterogeneous structure catalytic separation composite membrane.

2. The method for preparing the novel heterostructure catalytic separation composite membrane according to claim 1, characterized in that, The two-dimensional sheet material in step S1 is selected from one of two-dimensional graphene oxide, molybdenum disulfide, or boron nitride; the sheet size of the two-dimensional sheet material is 1-5 μm and the thickness is 0.3-2 nm.

3. The method for preparing the novel heterostructure catalytic separation composite membrane according to claim 1, characterized in that, The metal salt solution in step S1 is selected from ferrous chloride, ferrous sulfate, palladium chloride, chloroplatinic acid, silver nitrate, or copper nitrate; the mass ratio of the two-dimensional sheet material to the metal salt in the metal salt solution is 1:1-1.5; the surfactant is selected from polyvinylpyrrolidone, sodium dodecyl sulfate, or hexadecyltrimethylammonium bromide; the acid used to adjust the pH value is acetic acid or nitric acid, and the adjusted pH value is 5-8.

4. The method for preparing the novel heterostructure catalytic separation composite membrane according to claim 1, characterized in that, In step S1, the hydrothermal reaction temperature is 150-220℃ and the reaction time is 6-18h; the centrifugal cleaning speed is 5000-12000r / min and the drying temperature is 40-60℃.

5. The method for preparing the novel heterostructure catalytic separation composite membrane according to claim 1, characterized in that, The weight percentages of each component in the reaction product in step S1 are as follows: 0.5-2 parts of two-dimensional sheet material, 0.5-10 parts of metal salt solution, 0.01-0.05 parts of surfactant, and 60-100 parts of deionized water.

6. The method for preparing the novel heterostructure catalytic separation composite membrane according to claim 1, characterized in that, The polymer material in step S2 is selected from one of polysulfone, polyethersulfone, polyvinylidene fluoride, cellulose acetate, or polyacrylonitrile; the hydrophilic polymer is one of hydroxypropyl cellulose with amino, carboxyl, or hydroxyl groups, polylysine, polyaspartic acid, polyamino acid, or chitosan; the solvent is selected from one of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone.

7. The method for preparing the novel heterostructure catalytic separation composite membrane according to claim 1, characterized in that, In step S2, the weight proportions of each component in the casting solution are as follows: 8-16 parts of polymer material, 77-88 parts of solvent, 1-3 parts of hydrophilic polymer, and 1-3 parts of two-dimensional sheet catalyst. The two-dimensional sheet catalyst is added in the form of a mixed solution containing it, which is composed of the two-dimensional sheet catalyst and the solvent, and its total weight proportion is 3-5 parts.

8. The method for preparing the novel heterostructure catalytic separation composite membrane according to claim 1, characterized in that, The heating and stirring temperature in step S2 is 60°C; the substrate is nonwoven fabric; and the non-solvent used in the non-solvent induction method is water.

9. A novel heterostructure catalytic separation composite membrane prepared by the method described in any one of claims 1-8.

10. The application of a novel heterogeneous catalytic separation composite membrane as described in claim 9 in the field of wastewater treatment, characterized in that, The pollutants in the wastewater include any one or a combination of two or more of the following: methylene blue, orange-yellow, methyl violet, norfloxacin, enrofloxacin, and levofloxacin.

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