Preparation method and application of electrospinning solidified snc heterogeneous doped iron-copper bimetallic catalyst

Abstract

The present application belongs to the technical field of bimetallic catalysts, and relates to a preparation method of an electrospinning solidified SNC heterogeneous doped iron-copper bimetallic catalyst, comprising: dispersing cetyltrimethylammonium bromide in N,N-dimethylformamide, adding melamine and thiocyanuric acid, adding iron salt and copper salt after uniform dispersion, and then adding polyethyleneimine, stirring and centrifuging, and drying the precipitate; the precipitate is prepared into the SNC heterogeneous doped iron-copper bimetallic catalyst after secondary pyrolysis, and finally the obtained catalyst is solidified by using an electrospinning method. The electrospinning solidified bimetallic catalyst can achieve the purpose of efficient catalytic degradation of antibiotics. The compounds used in the whole synthesis process are low in price, the preparation process is simple to operate, and no secondary pollutants are generated. The problem of the aggregation tendency of the bimetallic catalyst is solved, the catalyst activity and stability are improved, and the bimetallic catalyst has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of bimetallic catalysis technology, and relates to bimetallic iron-based catalysts, particularly to a method for preparing and applying an electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst. Background Technology

[0002] Over the past few decades of production and development, tetracycline (TC), as one of the world's most widely prescribed antimicrobial agents, has been extensively used in aquaculture, human treatment, and agriculture due to its broad spectrum and low cost, bringing enormous benefits to humankind. However, due to insufficient bioavailability, some TC is released into the wastewater environment as metabolites, leading to the gradual accumulation of TC in natural water bodies and posing a significant threat to environmental safety. Therefore, the treatment of TC-contaminated wastewater is an urgent and pressing task.

[0003] In recent years, metallic copper, exhibiting similar behavior to iron-based heterogeneous Fenton catalysts, has attracted widespread research interest due to its wide pH adaptability. Furthermore, the positive synchronicity effect between iron and copper can enhance catalytic performance, making the construction of iron-copper bimetallic nanoparticles as heterogeneous catalysts a hot topic in Fenton research. However, nanoparticles, due to their inherent high surface energy, tend to aggregate, inevitably negatively impacting the catalytic activity and stability of the catalyst. Compared to the inherent defects of nanoparticle structures, with the rapid development of electrospinning technology, one-dimensional nanofiber structures possess a high axial ratio, enabling rapid and long-distance electron transport and exhibiting superior catalytic activity in many reactions. Among them, porous carbon nanofibers can promote electron transfer reaction kinetics and enhance catalytic activity, possessing unique research value in the field of catalysts. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the purpose of this invention is to disclose a method for preparing an electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst.

[0005] Technical solution

[0006] A method for preparing an electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst includes the following steps:

[0007] A) Dissolve hexadecyltrimethylammonium bromide in N,N-dimethylformamide and disperse it. Add melamine and thiocyanuric acid, disperse evenly, then add iron salt and copper salt, then add polyethyleneimine, stir and centrifuge, and dry the precipitate.

[0008] B) The resulting precipitate is washed thoroughly with water and ethanol, and dried at 60–90°C for 8–16 h, preferably at 80°C for 12 h. The resulting solid is placed in a muffle furnace and calcined at 500–550°C for 2 h at a heating rate of 5°C / min, preferably at 550°C. After cooling to room temperature, it is pyrolyzed in an inert atmosphere at 700–900°C for 2–4 h, preferably at 800°C for 2 h, with a heating rate of 3–10°C / min. -1 5℃·min is preferred -1 Remove and cool to room temperature, grind through a 200-mesh sieve to obtain the SNC multiphase doped iron-copper bimetallic catalyst;

[0009] C) Acrylonitrile was added to a dimethylformamide solution and ultrasonically homogenized. Polyurethane and the prepared SNC multiphase doped iron-copper bimetallic catalyst were added separately. The mixture was stirred at 98°C for 2 hours to obtain a polymer / solvent system. Using this as the shell polymer, core-shell electrospinning was performed to obtain an electrospinned and cured SNC multiphase doped iron-copper bimetallic catalyst.

[0010] In a preferred embodiment of the present invention, the iron salt in step A) is any one of ferrous chloride, ferric chloride, or ferric sulfate, preferably ferrous chloride.

[0011] In a preferred embodiment of the present invention, the copper salt in step A) is any one of copper nitrate, copper chloride, or copper sulfate, with copper nitrate being preferred.

[0012] In a preferred embodiment of the present invention, the mass and volume ratio of hexadecyltrimethylammonium bromide: N,N-dimethylformamide: melamine: thiocyanuric acid: ferrous chloride trihydrate: copper nitrate trihydrate: polyethyleneimine in step A) is 0.2g:40mL:1g:1g:0.6-2g:0.6-2g:0.4g, preferably 0.2g:40mL:1g:1g:1g:1.3g:0.4g.

[0013] In a preferred embodiment of the present invention, the inert atmosphere described in step B) is nitrogen or argon.

[0014] In a preferred embodiment of the present invention, the mass and volume ratio of polyacrylonitrile: dimethylformamide: polyurethane: SNC multiphase doped iron-copper bimetallic catalyst in step C) is 1-1.5g: 10-20ml: 1-1.5g: 0.5-2g, preferably 1.14g: 10ml: 1.00g: 0.86g.

[0015] In the preferred embodiment of the present invention, the core-shell electrospinning described in step C) involves injecting the core solution and shell polymer through an injection pump. The core solution is prepared by dissolving 0.8g of polymethyl methacrylate in 10ml of dimethylformamide. A grounded silicon wafer immersed in a non-solvent is used as the collector. A 1:1 (v / v) mixture of ethanol and acetone is filled into a collector, and the fiber is directly collected therein. The fiber is then removed and air-dried at room temperature to remove the solvent, thus obtaining the final product.

[0016] Another objective of this invention is to use the electrospun solidified SNC multiphase doped iron-copper bimetallic catalyst as a photocatalyst for the removal of antibiotics, especially tetracycline (TC), from wastewater using Fenton-like oxidation.

[0017] Experiments simulating tetracycline-containing wastewater showed that when the antibiotic concentration was 10 mg / L, adding 10 mg of photocatalyst to 100 mL of solution and stirring thoroughly resulted in efficient degradation of the antibiotic within 90 min, providing reliable theoretical and practical support for practical applications.

[0018] This invention uses a co-precipitation method to prepare the catalyst, which is simple to operate, produces uniform mixing, and has stable effects. It enables effective SNC multiphase doping. By combining SNC multiphase doping with electrospinning curing to stabilize the catalyst effect, the synergistic effect of iron and copper bimetals is enhanced, which effectively promotes the efficient activation of H2O2 and PMS, thereby improving the Fenton-like oxidation effect.

[0019] The features of this invention are:

[0020] (1) The iron-copper bimetallic catalyst synthesized in this invention successfully enhances the synergistic effect between iron and copper by co-precipitation method by doping with SNC. Combined with electrospinning to solidify the catalyst, the bimetallic controllable preparation and structure regulation technology are realized.

[0021] (2) The prepared catalyst has a larger specific surface area, stable catalyst effect, enhanced catalytic selectivity and activity, provided more catalytic active sites to accelerate redox reaction, can realize rapid and long-distance electron transport, and significantly improve its ability to catalyze the degradation of pollutants.

[0022] (3) The preparation process of this invention is simple, the cost is low, the catalyst efficiency is high and the regeneration performance is excellent, and it has a wide range of application prospects.

[0023] All reagents used in this invention are commercially available.

[0024] Beneficial effects

[0025] This invention discloses a method for preparing SNC multiphase doped iron-copper bimetallic catalysts via electrospinning curing. The preparation process involves simple reaction conditions, achieving highly efficient catalytic degradation of antibiotics through electrospinning curing of the bimetallic catalyst. The compounds used in the entire synthesis process are inexpensive, and the experimental operation is simple and does not generate secondary pollutants. This method addresses the tendency of bimetallic catalyst aggregation, improves catalyst activity and stability, and has broad application prospects due to its simple preparation process. Attached Figure Description

[0026] Figure 1 Scanning electron microscopy (SEM) of the SNC multiphase doped iron-copper bimetallic catalyst synthesized in Example 1. Detailed Implementation

[0027] The present invention will be described in detail below with reference to embodiments, so that those skilled in the art can better understand the present invention, but the present invention is not limited to the following embodiments.

[0028] Example 1

[0029] A method for preparing an electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst includes the following steps:

[0030] a) Dissolve 0.4g of cetyltrimethylammonium bromide in 80ml of N,N-dimethylformamide and stir to disperse evenly. Then add 2g of melamine and 2g of thiocyanuric acid and stir for 0.5h. Add 1g of ferrous chloride trihydrate and 1.3g of copper nitrate trihydrate and stir for 2h. Finally, add 0.8g of polyethyleneimine and stir for 16h before centrifuging.

[0031] b) Wash the obtained precipitate three times alternately with water and ethanol, dry it at 80°C for 8 hours, and grind it into powder;

[0032] c) Place the obtained powder in a crucible and heat it in an air atmosphere in a muffle furnace for carbonization at a heating rate of 5°C / min. -1 After reaching 550℃, keep it for 2 hours, and then remove it after cooling to room temperature;

[0033] d) Place the powder obtained in step c) in a tube furnace and pyrolyze it under a nitrogen atmosphere at a heating rate of 5°C / min. -1 After reaching 800℃, it is kept for 2 hours. After cooling to room temperature, it is washed with deionized water until the filtrate is neutral. Then it is dried, ground and sieved to obtain a 200-mesh SNC multiphase doped iron-copper bimetallic catalyst.

[0034] e) 1.14 g of polyacrylonitrile was added to 10 ml of dimethylformamide solution to obtain solution A. The mixture was ultrasonically stirred for 2 h. Then, 0.86 g of catalyst material and 1 g of TPU obtained in d) were added to solution A and mixed uniformly at 98 °C. Afterward, core-shell electrospinning was performed through a customized nozzle. The inner diameter of the core fluid opening was 0.30 mm, and the inner diameter of the shell fluid opening was 0.80 mm. 0.8 g of PMMA was dissolved in 10 ml of DMF as the core fluid. The above polymer / solvent system was used as the shell polymer. The electrospinning core and shell polymer were connected... The material was injected via a syringe pump at flow rates of 6.0 and 7.0 μL / min, respectively, maintaining a potential difference of 10 kV and a distance of 4.0 cm between the needle (26 pressure gauge) and the collector. A grounded silicon wafer immersed in a non-solvent was used as the collector. Simultaneously, a 1:1 (v / v) mixture of ethanol and acetone was filled into the collector. The fiber was directly collected in the bath containing the 1:1 (v / v) mixture of ethanol and acetone. The collected material was removed from the bath and air-dried at room temperature to remove the solvent, thus obtaining an electrospun solidified SNC multiphase doped iron-copper bimetallic catalyst.

[0035] The SEM image of the catalyst shows that the surface has a wrinkled structure, indicating that the bimetallic catalyst has been successfully doped, has a large specific surface area, and provides more active sites.

[0036] 10 mg of the prepared product was added to 100 mL of a tetracycline solution with a concentration of 10 mg / L, and the reaction was carried out for 120 min. The degradation rate of the tetracycline antibiotic was 90.6%.

[0037] Example 2

[0038] A method for preparing an electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst includes the following steps:

[0039] a) Dissolve 0.4g of cetyltrimethylammonium bromide in 80ml of N,N-dimethylformamide and stir to disperse evenly. Then add 2g of melamine and 2g of thiocyanuric acid and stir for 0.5h. Add 1g of ferrous chloride trihydrate and 1g of copper nitrate trihydrate and stir for 2h. Finally, add 0.8g of polyethyleneimine and stir for 16h before centrifuging.

[0040] b) Wash the obtained precipitate three times alternately with water and ethanol, dry it at 80°C for 12 hours, and grind it into powder;

[0041] c) Place the powder obtained in step b) into a crucible and heat it in an air atmosphere in a muffle furnace for carbonization at a heating rate of 5°C / min. -1 After reaching 550℃, keep it for 2 hours, and then remove it after cooling to room temperature;

[0042] d) Place the powder obtained in step c) in a tube furnace and pyrolyze it under a nitrogen atmosphere at a heating rate of 3°C / min.-1 After reaching 800℃, it is kept for 2 hours. After cooling to room temperature, it is washed with deionized water until the filtrate is neutral. Then it is dried, ground and sieved to obtain a 200-mesh SNC multiphase doped iron-copper bimetallic catalyst.

[0043] e) 1.14 g of polyacrylonitrile was added to 10 mL of dimethylformamide solution to obtain solution A. The mixture was ultrasonically stirred for 2 h. Then, 0.86 g of catalyst material and 1 g of TPU obtained in d) were added to solution A and mixed evenly at 98 °C. After that, core-shell electrospinning was performed through a customized nozzle. The inner diameter of the core fluid opening was 0.30 mm, and the inner diameter of the shell fluid opening was 0.80 mm. 0.8 g of PMMA was dissolved in 10 mL of DMF as the core fluid. The above polymer / solvent system was used as the shell polymer. The electrospinning core and shell polymer were used as the core fluid. The electrospinning solidified SNC multiphase doped iron-copper bimetallic catalyst was obtained by injecting the material at flow rates of 6.0 and 7.0 μL / min using an injection pump, maintaining a potential difference of 10 kV and a distance of 4.0 cm between the needle (26 pressure gauge) and the collector. A grounded silicon wafer immersed in a non-solvent was used as the collector. A 1:1 (v / v) mixture of ethanol and acetone was filled into the collector. The fiber was directly collected in the bath containing the 1:1 (v / v) mixture of ethanol and acetone. The collected material was removed from the bath and air-dried at room temperature to remove the solvent, thus obtaining the electrospinning solidified SNC multiphase doped iron-copper bimetallic catalyst.

[0044] 10 mg of the prepared product was added to 100 mL of a tetracycline solution with a concentration of 10 mg / L, and the reaction was carried out for 120 min. The degradation rate of the tetracycline antibiotic was 85.8%.

[0045] Example 3

[0046] A method for preparing an electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst includes the following steps:

[0047] a) Dissolve 0.4g of cetyltrimethylammonium bromide in 80ml of N,N-dimethylformamide and stir to disperse evenly. Then add 2g of melamine and 2g of thiocyanuric acid and stir for 0.5h. Add 1g of ferrous chloride trihydrate and 0.5g of copper nitrate trihydrate and stir for 2h. Finally, add 0.8g of polyethyleneimine and stir for 16h before centrifuging.

[0048] b) Wash the obtained precipitate with water and ethanol alternately three times, dry it at 60°C for 8 hours, and grind it into powder;

[0049] c) Place the powder obtained in step b) into a crucible and heat it in an air atmosphere in a muffle furnace for carbonization at a heating rate of 5°C / min. -1 After reaching 550℃, keep it for 2 hours, and then remove it after cooling to room temperature;

[0050] d) Place the powder obtained in step c) in a tube furnace and pyrolyze it under a nitrogen atmosphere at a heating rate of 3°C / min. -1 After reaching 800℃, it is kept for 2 hours. After cooling to room temperature, it is washed with deionized water until the filtrate is neutral. Then it is dried, ground and sieved to obtain a 200-mesh SNC multiphase doped iron-copper bimetallic catalyst.

[0051] e) 1.14 g of polyacrylonitrile was added to 10 ml of dimethylformamide solution to obtain solution A. The mixture was ultrasonically stirred for 2 h. Then, 0.86 g of catalyst material and 1 g of TPU obtained in d) were added to solution A and mixed evenly at 98 °C. After that, core-shell electrospinning was performed through a customized nozzle. The inner diameter of the core fluid opening was 0.30 mm, and the inner diameter of the shell fluid opening was 0.80 mm. 0.8 g of PMMA was dissolved in 10 ml of DMF as the core liquid. The above polymer / solvent system was used as the shell polymer. The electrospinning core and shell polymers were... The material was injected via a syringe pump at flow rates of 6.0 and 7.0 μL / min, respectively. A potential difference of 10 kV and a distance of 4.0 cm were maintained between the needle (26 pressure gauge) and the collector. A grounded silicon wafer immersed in a non-solvent was used as the collector. At the same time, a 1:1 (v / v) mixture of ethanol and acetone was filled into the collector. The fiber was directly collected in the bath containing the 1:1 (v / v) mixture of ethanol and acetone. The collected material was removed from the bath and air-dried at room temperature to remove the solvent, thus obtaining an electrospun solidified SNC multiphase doped iron-copper bimetallic catalyst.

[0052] 10 mg of the prepared product was added to 100 mL of a tetracycline solution with a concentration of 10 mg / L, and the reaction was carried out for 120 min. The degradation rate of the tetracycline antibiotic was 80.4%.

[0053] Example 4

[0054] A method for preparing an electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst includes the following steps:

[0055] a) Dissolve 0.4g of cetyltrimethylammonium bromide in 80ml of N,N-dimethylformamide and stir until evenly dispersed. Then add 2g of melamine and 2g of thiocyanuric acid and stir for 0.5h. Add 2g of ferrous chloride trihydrate and 1g of copper nitrate trihydrate and stir for 2h. Finally, add 0.8g of polyethyleneimine and stir for 16h before centrifuging.

[0056] b) Wash the obtained precipitate three times alternately with water and ethanol, dry it at 80°C for 12 hours, and grind it into powder;

[0057] c) Place the powder obtained in step b) into a crucible and heat it in an air atmosphere in a muffle furnace for carbonization at a heating rate of 5°C / min. -1 After reaching 550℃, keep it for 2 hours, and then remove it after cooling to room temperature;

[0058] d) Place the powder obtained in step c) in a tube furnace and pyrolyze it under a nitrogen atmosphere at a heating rate of 5°C / min. -1 After reaching 800℃, it is kept for 2 hours. After cooling to room temperature, it is washed with deionized water until the filtrate is neutral. Then it is dried, ground and sieved to obtain a 200-mesh SNC multiphase doped iron-copper bimetallic catalyst.

[0059] e) 1.134 g of polyacrylonitrile was added to 10 ml of dimethylformamide solution to obtain solution A. The mixture was ultrasonically stirred for 2 h. Then, 0.86 g of catalyst material and 1 g of TPU obtained in d) were added to solution A and mixed evenly at 98 °C. After that, core-shell electrospinning was performed through a customized nozzle. The inner diameter of the core fluid opening was 0.30 mm, and the inner diameter of the shell fluid opening was 0.80 mm. 0.8 g of PMMA was dissolved in 10 ml of DMF as the core liquid. The above polymer / solvent system was used as the shell polymer. The electrospinning core and shell polymers were... The material was injected via a syringe pump at flow rates of 6.0 and 7.0 μL / min, respectively. A potential difference of 10 kV and a distance of 4.0 cm were maintained between the needle (26 pressure gauge) and the collector. A grounded silicon wafer immersed in a non-solvent was used as the collector. At the same time, a 1:1 (v / v) mixture of ethanol and acetone was filled into the collector. The fiber was directly collected in the bath containing the 1:1 (v / v) mixture of ethanol and acetone. The collected material was removed from the bath and air-dried at room temperature to remove the solvent, thus obtaining an electrospun solidified SNC multiphase doped iron-copper bimetallic catalyst.

[0060] 10 mg of the prepared product was added to 100 mL of a tetracycline solution with a concentration of 10 mg / L, and the reaction was carried out for 120 min. The degradation rate of the tetracycline antibiotic was 78.9%.

[0061] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made using the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing an electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst, characterized in that, Includes the following steps: A) Dissolve and disperse hexadecyltrimethylammonium bromide in N,N-dimethylformamide, add melamine and thiocyanuric acid, disperse evenly, add ferrous chloride trihydrate and copper nitrate trihydrate, then add polyethyleneimine, stir, centrifuge, precipitate and dry. The mass and volume ratio of hexadecyltrimethylammonium bromide:N,N-dimethylformamide:melamine:thiocyanuric acid:ferrous chloride trihydrate:copper nitrate trihydrate:polyethyleneimine is 0.2g:40mL:1g:1g:0.6~2g:0.6~2g:0.4g; B) The resulting precipitate was washed with water and ethanol sequentially, dried at 60–90 °C for 8–16 h, and the resulting solid was placed in a muffle furnace and calcined at 500–550 °C for 2 h at a heating rate of 5 °C / min. After cooling to room temperature, it was pyrolyzed at 700–900 °C for 2–4 h in an inert atmosphere at a heating rate of 3–10 °C / min. -1 Remove and cool to room temperature, grind through a 200-mesh sieve to obtain the SNC multiphase doped iron-copper bimetallic catalyst; C) Acrylonitrile was added to a dimethylformamide solution and ultrasonically homogenized. Polyurethane and SNC multiphase doped iron-copper bimetallic catalyst were added separately and stirred at 98°C for 2 hours to obtain a polymer / solvent system. Using this as the shell polymer, core-shell electrospinning was performed to obtain electrospinned solidified SNC multiphase doped iron-copper bimetallic catalyst.

2. The method for preparing the electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst according to claim 1, characterized in that: In step A), the mass and volume ratio of hexadecyltrimethylammonium bromide: N,N-dimethylformamide: melamine: thiocyanuric acid: ferrous chloride trihydrate: copper nitrate trihydrate: polyethyleneimine is 0.2g:40mL:1g:1g:1g:1.3g:0.4g.

3. The method for preparing the electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst according to claim 1, characterized in that: In step B), the precipitate was washed with water and ethanol sequentially, dried at 80°C for 12 hours, and the resulting solid was placed in a muffle furnace and calcined at 550°C for 2 hours at a heating rate of 5°C / min. After cooling to room temperature, it was pyrolyzed at 800°C for 2 hours in an inert atmosphere at a heating rate of 5°C / min. -1 The sample was removed, cooled to room temperature, and ground through a 200-mesh sieve to obtain the SNC multiphase doped iron-copper bimetallic catalyst.

4. The method for preparing the electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst according to claim 1, characterized in that: In step B), the inert atmosphere is nitrogen or argon.

5. The method for preparing the electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst according to claim 1, characterized in that: In step C), the mass and volume ratio of polyacrylonitrile: dimethylformamide: polyurethane: SNC multiphase doped iron-copper bimetallic catalyst is 1~1.5g: 10~20ml: 1~1.5g: 0.5~2g.

6. The method for preparing the electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst according to claim 5, characterized in that: In step C), the mass-to-volume ratio of the polyacrylonitrile:dimethylformamide:polyurethane:SNC multiphase doped iron-copper bimetallic catalyst is 1.14g:10ml:1.00g:0.86g.

7. The method for preparing the electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst according to claim 1, characterized in that: In step C), the core-shell electrospinning involves injecting the core solution and shell polymer through an injection pump. The core solution is prepared by dissolving 0.8g of polymethyl methacrylate in 10mL of dimethylformamide. A grounded silicon wafer immersed in a non-solvent is used as the current collector. A mixture of ethanol and acetone with a volume ratio of 1:1 is filled into a collector, and the fiber is collected directly in it. Then, the fiber is removed and air-dried at room temperature to remove the solvent, thus obtaining the final product.

8. The electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst prepared by any one of the methods described in claims 1-7.

9. The application of the electrospinning-cured SNC multiphase doped iron-copper bimetallic catalyst as described in claim 8, characterized in that: It was applied to the removal of tetracycline from wastewater using Fenton-like oxidation.

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