Multifunctional nanoscale enzyme composite material based on MXene and preparation method and application thereof

Abstract

The application discloses a multifunctional nano-enzyme composite material based on MXene as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) adding an etchant to a MAX phase precursor to react, and obtaining MXene nanosheets after the reaction; (2) dispersing the MXene nanosheets in a solvent to obtain a suspension, adding a mixed solution containing Fe 2+ and Fe 3+ into the suspension to obtain a mixed solution, adjusting the pH of the mixed solution to react, and obtaining a MXene / Fe3O4 composite material after the reaction; (3) dispersing the MXene / Fe3O4 composite material in a silver nitrate solution, adding a reducing agent to react, and obtaining an AgNPs / MXene / Fe3O4 composite material after the reaction; (4) mixing the AgNPs / MXene / Fe3O4 composite material with a polymer solution to obtain a spinning solution; and spinning the spinning solution into a film through an electrostatic spinning equipment to obtain the multifunctional nano-enzyme composite material based on MXene. The composite material has the functions of efficient antibiosis, organic pollutant degradation and intelligent response, can cope with complex environmental pollution treatment requirements, and fills the gap of traditional materials in the aspects of multifunctionality and stability.

Description

Technical Field

[0001] This invention belongs to the field of functional materials and environmental engineering technology, specifically relating to the preparation and application of multifunctional nanocomposite materials, covering photocatalysis, antibacterial materials and pollutant degradation technology, and is widely used in fields such as medical and health care, environmental purification and smart packaging. Background Technology

[0002] With the rapid development of industrialization and urbanization, the massive discharge of organic pollutants such as antibiotics has triggered widespread environmental and health problems. The overuse and improper handling of antibiotics not only leads to water pollution but also promotes the emergence and spread of drug-resistant bacteria, posing a significant challenge to traditional antibacterial therapies. Furthermore, many organic pollutants are difficult to degrade and persist in the environment, threatening the safety of ecosystems. Therefore, developing a multifunctional material that combines highly efficient antibacterial properties with the ability to degrade organic pollutants has become a research hotspot in the fields of materials science and environmental science.

[0003] In addressing these challenges, nanomaterials, with their unique physicochemical properties, have shown broad application prospects in the field of environmental remediation. Two-dimensional transition metal carbides and nitrides (MXenes), as an emerging class of nanomaterials, have attracted widespread attention due to their high conductivity, large specific surface area, and abundant surface functional groups. MXenes have shown great potential in photocatalysis, organic pollutant degradation, and biosensing. However, MXene nanosheets are prone to aggregation in practical applications, leading to decreased dispersibility and stability, limiting their full functionality. Nanosilver (AgNPs) have become a hot topic in antibacterial material research due to their broad-spectrum and highly efficient antibacterial properties. AgNPs can disrupt bacterial cell walls and membrane structures by releasing silver ions, interfering with cellular metabolic processes to achieve antibacterial and bactericidal effects. However, single AgNPs suffer from problems such as easy aggregation, easy attenuation of antibacterial efficacy, and high cost, limiting their widespread application in practice. Magnetic nanoparticles Fe3O4, due to their peroxidase-mimicking activity, have been widely used in pollutant degradation, catalysis, and biomedicine. Fe3O4 nanoparticles can promote the degradation of organic pollutants through enzyme-like catalytic activity. However, Fe3O4 has weak antibacterial properties and is prone to oxidation and aggregation in complex environments, affecting its long-term stability.

[0004] To overcome these limitations, researchers have attempted to composite materials such as MXene, AgNPs, and Fe3O4 to construct multifunctional integrated systems. For example, the composite of MXene and TiO2 has been used to improve photocatalytic performance, while the combination of MXene and metal oxides has shown potential in antibacterial and pollutant degradation. However, these composite materials are typically single-function and lack responsiveness to external stimuli, making them difficult to adapt to the diverse needs of complex environments. Therefore, developing composite materials that combine multi-responsiveness, high-efficiency antibacterial properties, and environmental adaptability has become an important research goal.

[0005] While existing antibacterial and pollutant-degrading materials possess certain functionalities, they suffer from significant shortcomings in terms of multifunctionality, dispersibility, photocatalytic efficiency, and reusability, limiting their application in complex environments. Specific drawbacks and their causes are as follows:

[0006] (1) Single function, difficult to meet multiple needs: Existing materials are mostly based on a single function, making it difficult to simultaneously achieve multiple functional requirements such as antibacterial and antibiotic degradation, resulting in poor adaptability in complex application environments. This is because traditional material design focuses on a single function and lacks multi-functional integration.

[0007] (2) Poor dispersibility and unstable performance: Nanomaterials such as MXene, nano silver and Fe3O4 are prone to agglomeration in the liquid phase, resulting in poor dispersibility and reduced activity, which affects their antibacterial and degradation effects. The agglomeration problem stems from the high-energy state of the nanomaterial surface, making it difficult for them to be uniformly distributed in the liquid phase.

[0008] (3) Narrow applicability and low efficiency of photocatalysis: Traditional photocatalytic materials rely on ultraviolet light and cannot efficiently utilize visible light, resulting in low efficiency in degrading organic pollutants under natural light conditions. This is mainly due to the large band gap of the materials, which can only absorb ultraviolet light, thus limiting their application.

[0009] (4) Poor reusability and lack of effective recycling methods: Most existing materials lack magnetic response function, making them difficult to recycle after use and unable to achieve efficient reuse, which increases material consumption and cost. Summary of the Invention

[0010] To overcome the shortcomings of existing technologies, this invention provides a multifunctional nanoenzyme composite material based on MXene, its preparation method, and its application.

[0011] In the first aspect, this invention proposes a multifunctional nanocomposite material based on MXene, which achieves antibacterial and pollutant degradation functions through optimized preparation process. The specific technical solution is as follows:

[0012] (1) An etchant was added to the MAX phase precursor and reacted. After the reaction was completed, MXene nanosheets were obtained.

[0013] (2) MXene nanosheets were dispersed in a solvent to obtain a suspension, and Fe was added to the suspension. 2+ and Fe 3+ The mixed solution was used to obtain a mixed liquid. The pH of the mixed liquid was adjusted to carry out the reaction. After the reaction was completed, the MXene / Fe3O4 composite material was obtained.

[0014] (3) The MXene / Fe3O4 composite material was dispersed in silver nitrate solution, and a reducing agent was added to react. After the reaction was completed, AgNPs / MXene / Fe3O4 composite material was obtained.

[0015] (4) The AgNPs / MXene / Fe3O4 composite material is mixed with a polymer solution to obtain a spinning solution; the spinning solution is spun into a film using an electrospinning device to obtain a multifunctional nanocomposite material based on MXene.

[0016] The composite material obtained through the technical solution of this invention has excellent dispersibility, multiple synergistic functions and good structural stability, and can meet the requirements of efficient antibacterial, pollutant degradation and reuse in complex environments.

[0017] In step (1) of the present invention, the purpose of the etching solution reaction is to remove the metal layer. After the reaction is completed, two-dimensional MXene nanosheets can be obtained.

[0018] In step (3) of the present invention, the purpose of the reducing agent is to load AgNPs in situ on MXene / Fe3O4, thereby loading AgNPs onto the surface of the MXene / Fe3O4 composite material.

[0019] In step (1):

[0020] The MAX phase precursor material includes at least one of Ti3AlC2, Ti2AlC, and Nb2AlC.

[0021] The etchant includes at least one of the following: hydrofluoric acid (HF) (10-40%), hydrogen chloride (HCl), and sodium fluoride (NaF) in a 6:1 mixture.

[0022] The reaction temperature is 20-45℃, and the reaction time is 12-24h.

[0023] Step (1) also includes cleaning and drying after the etching solution reaction is complete.

[0024] The cleaning method is centrifugation, with a centrifugation speed of 8000-10000 r / min and a time of 1-3 min.

[0025] The cleaning solution includes at least one of anhydrous ethanol, anhydrous methanol, and deionized water.

[0026] The cleaning step (1) involves using a cleaning solution to remove residual acidic substances and byproducts from the MXene nanosheets.

[0027] The drying method is vacuum drying, the drying temperature is 40-80℃, and the drying time is 12-24 hours.

[0028] In step (2):

[0029] The concentration of the MXene nanosheets in the suspension is 1-5 mg / mL.

[0030] The solvent is deionized water.

[0031] In the Fe-containing 2+ and Fe 3+ In the mixed solution, the Fe 3+ The concentration is 0.1-0.5 mol / L, and the Fe... 2+ The concentration is 0.05-0.3 mol / L.

[0032] In the Fe-containing 2+ and Fe 3+ In the mixed solution, Fe 3+ :Fe 2+ The molar ratio ranges from 1.8:1 to 2.2:1.

[0033] The pH value of the mixture is 8-10.

[0034] The pH adjuster of the mixture includes at least one of ammonia, sodium hydroxide, and sodium acetate.

[0035] The reaction temperature is 40-60℃, and the reaction time is 1-2 hours.

[0036] Step (2) also includes a cleaning step after the reaction is complete.

[0037] The cleaning method is centrifugation, the centrifugation speed is 300-500 rpm / min, and the number of cleaning cycles is 3-5.

[0038] The cleaning solution includes at least one of anhydrous ethanol, methanol, and deionized water.

[0039] In step (3):

[0040] The concentration of the silver nitrate solution is 0.1-0.5 mol / L.

[0041] The reducing agent includes at least one of ascorbic acid (10-50 mM) or polydopamine (0.5-2 mg / mL), wherein the molar ratio of ascorbic acid to silver nitrate is 1:10 to 1:2, and the molar ratio of polydopamine to silver nitrate is 1:100 to 1:50.

[0042] The reaction temperature is 20-50℃, and the reaction time is 3-6 hours.

[0043] In step (4):

[0044] The polymer is at least one of polyacrylonitrile (PAN), polycaprolactone (PCL), or polyurethane (PU).

[0045] The polymer concentration in the polymer solution is 5-20 wt%.

[0046] The mass ratio of the AgNPs / MXene / Fe3O4 composite material to the polymer solution is 1:10-2:10.

[0047] The electrospinning equipment has a voltage of 10-20kV, a distance of 15-20cm between the power supply and the receiving plate, a flow rate of 0.5-1mL / h for the injection pump, and a spinning temperature of 25-30℃.

[0048] The drying temperature is 40-50℃, and the time is 8-12 hours.

[0049] Secondly, the present invention provides a multifunctional nanocomposite material based on MXene, which is prepared by the method described above.

[0050] The mass ratio of MXene to Fe3O4 is controlled within the range of 1:1 to 1:2, and the loading of AgNPs is within the range of 1% to 10% of the total mass of the composite material, so as to achieve the best synergistic effect of each component.

[0051] Thirdly, the present invention provides an application of a multifunctional nanocomposite material based on MXene in antibacterial and antibiotic degradation in water.

[0052] In some embodiments, the application in water purification is preferably to kill harmful bacteria in the water, especially Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus.

[0053] In some embodiments, the application in water purification is preferably the degradation of antibiotics in the water, especially sulfamethoxazole and ofloxacin.

[0054] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0055] (1) Multifunctional integration performance:

[0056] The multifunctional nanocomposite material of this invention integrates antibacterial, organic pollutant degradation, and intelligent response functions, effectively solving the problem of single-function traditional materials. Through the high surface area and conductivity of MXene, the broad-spectrum antibacterial properties of nanosilver (AgNPs), and the enzyme-mimicking catalytic activity of Fe3O4, highly efficient antibacterial and pollutant remediation are achieved in complex environments.

[0057] (2) Highly efficient visible light catalytic performance:

[0058] This invention fully utilizes the synergistic effect of MXene, Fe3O4, and nano-silver to significantly improve the degradation efficiency of organic pollutants under visible light conditions. Compared with traditional photocatalytic materials that rely on ultraviolet light (such as TiO2), the material of this invention exhibits superior performance over a wider spectral range, greatly expanding its applicability in practical applications.

[0059] (3) Broad-spectrum antibacterial properties and long-term stability:

[0060] The material of this invention exhibits broad-spectrum antibacterial properties against a variety of microorganisms, including Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. The antibacterial effect is significantly enhanced through the uniform distribution of nano-silver and the synergistic effect of MXene, and the long-term stability of the antibacterial efficacy is achieved through photocatalytic release of silver ions.

[0061] (4) Structural stability and dispersion:

[0062] This invention uses electrospinning technology to uniformly disperse MXene, Fe3O4 and AgNPs in a polymer matrix, effectively avoiding the agglomeration problem of nanomaterials, improving the mechanical strength and overall structural stability of the composite material, and ensuring the long-term stability of antibacterial and degradation functions.

[0063] (5) Simple preparation process and industrialization potential:

[0064] This invention achieves low-cost, high-efficiency material preparation through a simple solution mixing, electrospinning, and heat treatment process. The adopted process has good operability and repeatability, meeting the needs of large-scale production and providing a reliable technical foundation for industrial applications.

[0065] (6) Advantages of targeted application:

[0066] The material of this invention exhibits significant advantages in water purification, effectively killing harmful bacteria in water (such as Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus) and degrading antibiotics (such as sulfamethoxazole), thus meeting the diverse needs of complex pollution control.

[0067] (7) Intelligent response characteristics:

[0068] The material of this invention has a photoresponsive function, which can dynamically adjust its antibacterial and catalytic properties according to external stimuli, thereby improving the material's adaptability and functionality in complex environments.

[0069] (8) Wide range of applications:

[0070] The multifunctional nanocomposite material of this invention can be widely used in medical devices, environmental purification, smart packaging and other fields, showing great application potential and economic value. Attached Figure Description

[0071] Figure 1 The image shows the morphology of the MXene nanosheets prepared in step (1) of Example 1.

[0072] Figure 2 The image shows the morphology of the MXene / Fe3O4 / AgNPs composite antibacterial fiber membrane prepared in step (4) of Example 1.

[0073] Figure 3 The morphology of the MXene / Fe3O4 composite antibacterial fiber membrane prepared in step (3) of Comparative Example 2 is shown.

[0074] Figure 4 Morphology of the MXene / AgNPs composite antibacterial fiber membrane prepared in step (3) of Comparative Example 3.

[0075] Figure 5 The image shows the morphology of the MXene nanosheets prepared in Comparative Example 7. Detailed Implementation

[0076] The method proposed in this invention will be further described below with reference to specific embodiments, but the implementation of the invention is not limited to the following examples.

[0077] Example 1:

[0078] (1) 1 g of Ti3AlC2 was added to 20 mL of 30% hydrofluoric acid (HF) solution, and the mixture was stirred at 40 °C and 400 rpm for 16 hours. After the reaction was completed, MXene nanosheets were obtained by centrifugation (9000 rpm, 2 minutes) and washed 5 times with deionized water until the pH was neutral. Then, the MXene nanosheets were dried in a vacuum environment at 60 °C for 20 hours.

[0079] (2) 200 mg of the obtained MXene nanosheets were dispersed in 100 mL of deionized water and sonicated for 10 minutes to obtain an MXene suspension with a concentration of 2 mg / mL. 20 mL of 0.1 M FeCl3 and 20 mL of 0.056 M FeCl2 were mixed and slowly added dropwise to the 2 mg / mL MXene suspension under magnetic stirring (400 rpm), while adjusting the pH to 8.5 with ammonia. The reaction was maintained at 45°C with stirring for 1.5 hours to allow Fe3O4 to form in situ on the surface of the MXene nanosheets. After the reaction, the MXene / Fe3O4 composite material was obtained by centrifugation (9000 rpm, 2 minutes) and washing repeatedly with deionized water.

[0080] (3) The MXene / Fe3O4 composite material obtained in step (2) was dispersed in 50 mL of silver nitrate (AgNO3) solution with a concentration of 0.3 mol / L. After stirring at 400 rpm at 20–50 °C for 0.5 hours, 10 mL of 1 mg / mL polydopamine was added to reduce silver ions in situ, thereby generating AgNPs / MXene / Fe3O4 composite material with uniformly loaded AgNPs.

[0081] (4) The AgNPs / MXene / Fe3O4 composite material was mixed with 10wt% polyacrylonitrile (PAN) solution at a mass ratio of 1:10, magnetically stirred for 30 minutes, and ultrasonically treated for 20 minutes at an ultrasonic power of 300W to obtain a uniform spinning precursor solution. The precursor solution was injected into an electrospinning device, a high voltage of 12kV was applied, the injection pump flow rate was set to 0.6mL / h, the distance between the receiving plate and the power supply was 18cm, and the spinning temperature was 28℃. Finally, the obtained fiber membrane was dried at 50℃ for 9 hours to obtain the MXene-based multifunctional nanoenzyme composite material.

[0082] The scanning electron microscope image of the MXene nanosheets prepared in step (1) of Example 1 is shown below. Figure 1 As shown, the morphology of the MXene / Fe3O4 / AgNPs composite antibacterial fiber membrane prepared in step (4) is illustrated by a scanning electron microscope image. Figure 2 As shown.

[0083] Example 2:

[0084] The difference between Example 2 and Example 1 is that in Example 2, the precursor Ti3AlC2 in step (1) of Example 1 is replaced with Nb2AlC, while the remaining steps and parameters are the same as in Example 1.

[0085] Example 3:

[0086] The difference between Example 3 and Example 1 is that in Example 3, the etchant in step (1) of Example 1 is replaced with a mixed solution of 9M hydrochloric acid (HCl) and 1g / mL sodium fluoride (NaF), instead of 30% hydrofluoric acid (HF) solution. The remaining steps and parameters are the same as in Example 1.

[0087] Example 4:

[0088] The difference between Example 4 and Example 1 is that in Example 4, during the synthesis of Fe3O4 in step (2), the Fe content was adjusted. 3 + with Fe 2+ The molar ratio was changed to 2.2:1 (20 mL of 0.1 M FeCl3 and 20 mL of 0.04545 M FeCl2), and the remaining steps and parameters were the same as in Example 1.

[0089] Example 5:

[0090] The difference between Example 5 and Example 1 is that in the synthesis of AgNPs in step (3) of Example 5, the reducing agent is replaced by 10 mL of 1 mg / mL polydopamine with 10 mL of 50 mM ascorbic acid, and the remaining steps and parameters are the same as in Example 1.

[0091] Example 6:

[0092] The difference between Example 6 and Example 1 is that in the synthesis of AgNPs in step (3) of Example 6, the concentration of silver nitrate (AgNO3) solution is increased to 0.5 mol / L and the concentration of polydopamine is increased to 2 mg / mL to increase the loading of AgNPs. The remaining steps and parameters are the same as in Example 1.

[0093] Example 7:

[0094] The difference between Example 7 and Example 1 is that in Example 7, the polymer matrix of electrospinning in step (4) is replaced with 10 wt% polyacrylonitrile (PAN) instead of 10 wt% polycaprolactone (PCL), while the remaining steps and parameters are the same as in Example 1.

[0095] Comparative Example 1:

[0096] Difference from Example 1: In this comparative example, MXene was not used in the preparation process; Fe3O4 and AgNPs were directly loaded onto the polyacrylonitrile (PAN) matrix.

[0097] (1) A mixed solution containing 0.1M FeCl3 and 0.056M FeCl2 (Fe3+ and Fe2+ molar ratio 1.8:1) was added to 20mL of deionized water. The pH was adjusted to 8.5 with ammonia under stirring. The reaction was maintained for 1.5 hours at 45℃. After the reaction, impurities were removed by centrifugation to obtain Fe3O4 nanoparticles.

[0098] (2) Fe3O4 nanoparticles were dispersed in a 0.3 mol / L silver nitrate (AgNO3) solution and stirred at 400 rpm. 10 mL of 1 mg / mL polydopamine was added to reduce silver ions in situ, generating a uniformly loaded AgNPs / Fe3O4 composite material.

[0099] (3) The AgNPs / Fe3O4 composite material was mixed with a 10wt% polyacrylonitrile (PAN) solution at a mass ratio of 1:10, magnetically stirred for 30 minutes, and ultrasonically treated for 20 minutes at a power of 300W to obtain a uniform spinning precursor solution. The precursor solution was injected into an electrospinning device, a high voltage of 12kV was applied, the injection pump flow rate was set to 0.6mL / h, the distance between the receiving plate and the power supply was 18cm, and the spinning temperature was 28℃. Finally, the obtained fiber membrane was dried at 50℃ for 9 hours to obtain a multifunctional nanoenzyme composite material.

[0100] Comparative Example 2:

[0101] Difference from Example 1: In this comparative example, AgNPs were not loaded in situ during the preparation process; only MXene / Fe3O4 composite material was prepared.

[0102] Specific steps:

[0103] (1) 1 g of Ti3AlC2 was added to 20 mL of 30% hydrofluoric acid (HF) solution, and the mixture was stirred at 40 °C and 400 rpm for 16 hours. After the reaction was completed, MXene nanosheets were obtained by centrifugation (9000 rpm, 2 minutes) and washed 5 times with deionized water until the pH was neutral. Then, the MXene nanosheets were dried in a vacuum environment at 60 °C for 20 hours.

[0104] (2) The obtained MXene nanosheets were dispersed in deionized water at a concentration of 2 mg / mL. A mixed solution containing 0.1 M FeCl3 and 0.056 M FeCl2 (Fe 3+ and Fe 2+ The MXene / Fe3O4 composite material was formed by adding the MXene suspension at a molar ratio of 1.8:1 and adjusting the pH to 8.5 with ammonia under stirring. The reaction was maintained for 1.5 hours at a temperature of 45°C. After the reaction, impurities were removed by centrifugation and washing.

[0105] (3) The MXene / Fe3O4 composite material was mixed with a 10wt% polyacrylonitrile (PAN) solution at a mass ratio of 1:10, magnetically stirred for 30 minutes, and ultrasonically treated for 20 minutes at a power of 300W to obtain a uniform spinning precursor solution. The precursor solution was injected into an electrospinning apparatus, a high voltage of 12kV was applied, the injection pump flow rate was set to 0.6mL / h, the distance between the receiving plate and the power supply was 18cm, and the spinning temperature was 28℃. Finally, the obtained fiber membrane was dried at 50℃ for 9 hours to obtain the MXene-based multifunctional nanoenzyme composite material.

[0106] The scanning electron microscope image of the MXene / Fe3O4 composite material prepared in step (3) of Comparative Example 2 is shown below. Figure 3 As shown.

[0107] Comparative Example 3:

[0108] Difference from Example 1: In this comparative example, Fe3O4 was not loaded in situ during the preparation process; AgNPs were directly loaded onto the MXene surface.

[0109] (1) 1 g of Ti3AlC2 was added to 20 mL of 30% hydrofluoric acid (HF) solution, and the mixture was stirred at 40 °C and 400 rpm for 16 hours. After the reaction was completed, MXene nanosheets were obtained by centrifugation (9000 rpm, 2 minutes) and washed 5 times with deionized water until the pH was neutral. Then, the MXene nanosheets were dried in a vacuum environment at 60 °C for 20 hours.

[0110] (3) The MXene composite material was dispersed in a 0.3 mol / L silver nitrate (AgNO3) solution and stirred at 400 rpm. 10 mL of 1 mg / mL polydopamine was added to reduce silver ions in situ to generate a uniformly loaded AgNPs / MXene composite material.

[0111] (4) The AgNPs / MXene composite material was mixed with a 10wt% polyacrylonitrile (PAN) solution at a mass ratio of 1:10, magnetically stirred for 30 minutes, and ultrasonically treated for 20 minutes at a power of 300W to obtain a uniform spinning precursor solution. The precursor solution was injected into an electrospinning apparatus, a high voltage of 12kV was applied, the injection pump flow rate was set to 0.6mL / h, the distance between the receiving plate and the power supply was 18cm, and the spinning temperature was 28℃. Finally, the obtained fiber membrane was dried at 50℃ for 9 hours to obtain the MXene-based multifunctional nanoenzyme composite material.

[0112] The scanning electron microscope image of the MXene / AgNPs composite material prepared in step (3) of Comparative Example 3 is shown below. Figure 4 As shown.

[0113] Comparative Example 4:

[0114] Difference from Example 1: In this comparative example, only Fe3O4 nanoparticles were used in the preparation process, and MXene and AgNPs were not added.

[0115] (1) A mixed solution containing 0.1M FeCl3 and 0.056M FeCl2 (Fe 3+ and Fe 2+ The mixture was added to 20 mL of deionized water at a molar ratio of 1.8:1. The pH was adjusted to 8.5 with ammonia under stirring. The reaction was maintained for 1.5 hours at a temperature of 45°C. After the reaction, impurities were removed by centrifugation and washing to form Fe3O4 nanoparticles.

[0116] (2) Fe3O4 nanoparticles were mixed with 10wt% polyacrylonitrile (PAN) solution at a mass ratio of 1:10, magnetically stirred for 30 minutes, and ultrasonically treated for 20 minutes at a power of 300W to obtain a uniform spinning precursor solution. The precursor solution was injected into an electrospinning apparatus, a high voltage of 12kV was applied, the injection pump flow rate was set to 0.6mL / h, the distance between the receiving plate and the power supply was 18cm, and the spinning temperature was 28℃. Finally, the obtained fiber membrane was dried at 50℃ for 9 hours to obtain a multifunctional nanoenzyme composite material based on MXene.

[0117] Comparative Example 5:

[0118] Difference from Example 1: No nanomaterials were added in this comparative example; only PAN was used to prepare the fiber membrane.

[0119] 10 wt% polyacrylonitrile (PAN) was injected into an electrospinning apparatus, a high voltage of 12 kV was applied, the injection pump flow rate was set to 0.6 mL / h, the distance between the receiving plate and the power supply was 18 cm, and the spinning temperature was 28 °C. Finally, the resulting fiber membrane was dried at 50 °C for 9 hours to obtain the PAN membrane material.

[0120] Comparative Example 6:

[0121] Difference from Example 1: This comparative example uses TiO2 nanoparticles instead of MXene.

[0122] Specific steps:

[0123] (1) Take 1g of 50nm TiO2 nanoparticles and wash them 5 times with deionized water. Then, place the MXene nanosheets in a vacuum environment at 60℃ and dry them for 20 hours.

[0124] (2) The obtained TiO2 nanoparticles were dispersed in deionized water at a concentration of 2 mg / mL. A mixed solution containing 0.1 M FeCl3 and 0.056 M FeCl2 (Fe 3+ and Fe 2+ The mixture was added to the MXene suspension at a molar ratio of 1.8:1. The pH was adjusted to 8.5 with ammonia under stirring conditions. The reaction was maintained for 1.5 hours at a temperature of 45°C. After the reaction, impurities were removed by centrifugation to form a TiO2 / Fe3O4 composite material.

[0125] (3) The TiO2 / Fe3O4 composite material was dispersed in a 0.3mol / L silver nitrate (AgNO3) solution and stirred at 400rpm. 10mL of 1mg / mL polydopamine was added to reduce silver ions in situ, and AgNPs / TiO2 / Fe3O4 composite material with uniform AgNPs was generated.

[0126] (4) The AgNPs / TiO2 / Fe3O4 composite material was mixed with 10wt% polyacrylonitrile (PAN) solution at a mass ratio of 1:10, magnetically stirred for 30 minutes, and ultrasonically treated for 20 minutes at an ultrasonic power of 300W to obtain a uniform spinning precursor solution. The precursor solution was injected into an electrospinning device, a high voltage of 12kV was applied, the injection pump flow rate was set to 0.6mL / h, the distance between the receiving plate and the power supply was 18cm, and the spinning temperature was 28℃. Finally, the obtained fiber membrane was dried at 50℃ for 9 hours to obtain a multifunctional nanoenzyme composite material based on TiO2.

[0127] Comparative Example 7:

[0128] Difference from Example 1: In the preparation of MXene in this comparative example, the etchant was changed from 30% HF to 9M hydrochloric acid (HCl) and 1 g / mL lithium fluoride (LiF).

[0129] Specific steps:

[0130] (1) 1 g of Ti3AlC2 was added to a mixed solution of 20 mL of 9 M hydrochloric acid and 2 g of lithium fluoride, and the mixture was stirred at 40 °C and 400 rpm for 16 hours. After the reaction was completed, MXene nanosheets were obtained by centrifugation (9000 rpm, 2 minutes) and washed 5 times with deionized water until the pH was neutral. Then, the MXene nanosheets were dried in a vacuum environment at 60 °C for 20 hours.

[0131] (2) The obtained MXene nanosheets were dispersed in deionized water at a concentration of 2 mg / mL. A mixed solution containing 0.1 M FeCl3 and 0.056 M FeCl2 (Fe 3+ and Fe 2+The MXene / Fe3O4 composite material was formed by adding the MXene suspension at a molar ratio of 1.8:1 and adjusting the pH to 8.5 with ammonia under stirring. The reaction was maintained for 1.5 hours at a temperature of 45°C. After the reaction, impurities were removed by centrifugation and washing.

[0132] (3) The MXene / Fe3O4 composite material was dispersed in a 0.3 mol / L silver nitrate (AgNO3) solution and stirred at 400 rpm. 10 mL of 1 mg / mL polydopamine was added to reduce silver ions in situ, and AgNPs / MXene / Fe3O4 composite material with uniform AgNPs was generated.

[0133] (4) The AgNPs / MXene / Fe3O4 composite material was mixed with 10wt% polyacrylonitrile (PAN) solution at a mass ratio of 1:10, magnetically stirred for 30 minutes, and ultrasonically treated for 20 minutes at an ultrasonic power of 300W to obtain a uniform spinning precursor solution. The precursor solution was injected into an electrospinning device, a high voltage of 12kV was applied, the injection pump flow rate was set to 0.6mL / h, the distance between the receiving plate and the power supply was 18cm, and the spinning temperature was 28℃. Finally, the obtained fiber membrane was dried at 50℃ for 9 hours to obtain the MXene-based multifunctional nanoenzyme composite material.

[0134] Comparative Example 8:

[0135] Difference from Example 1: In this comparative example, Fe was used in the preparation process of the MXene / Fe3O4 composite material. 3+ and Fe 2+ The molar ratio is changed to 4:1. The specific steps are as follows:

[0136] (1) 1 g of Ti3AlC2 was added to 20 mL of 30% hydrofluoric acid (HF) solution, and the mixture was stirred at 40 °C and 400 rpm for 16 hours. After the reaction was completed, MXene nanosheets were obtained by centrifugation (9000 rpm, 2 minutes) and washed 5 times with deionized water until the pH was neutral. Then, the MXene nanosheets were dried in a vacuum environment at 60 °C for 20 hours.

[0137] (2) The obtained MXene nanosheets were dispersed in deionized water at a concentration of 2 mg / mL. A mixed solution containing 0.1 M FeCl3 and 0.025 M FeCl3 (FeCl3 + FeCl3) was added. 3+ and Fe 2+ The MXene / Fe3O4 composite material was formed by adding the MXene suspension at a molar ratio of 1.8:1 and adjusting the pH to 8.5 with ammonia under stirring. The reaction was maintained for 1.5 hours at a temperature of 45°C. After the reaction, impurities were removed by centrifugation and washing.

[0138] (3) The MXene / Fe3O4 composite material was dispersed in a 0.3 mol / L silver nitrate (AgNO3) solution and stirred at 400 rpm. 10 mL of 1 mg / mL polydopamine was added to reduce silver ions in situ, and AgNPs / MXene / Fe3O4 composite material with uniform AgNPs was generated.

[0139] (4) The AgNPs / MXene / Fe3O4 composite material was mixed with 10wt% polyacrylonitrile (PAN) solution at a mass ratio of 1:10, magnetically stirred for 30 minutes, and ultrasonically treated for 20 minutes at an ultrasonic power of 300W to obtain a uniform spinning precursor solution. The precursor solution was injected into an electrospinning device, a high voltage of 12kV was applied, the injection pump flow rate was set to 0.6mL / h, the distance between the receiving plate and the power supply was 18cm, and the spinning temperature was 28℃. Finally, the obtained fiber membrane was dried at 50℃ for 9 hours to obtain the MXene-based multifunctional nanoenzyme composite material.

[0140] Comparative Example 9:

[0141] Difference from Example 1: In this comparative example, Ag3PO4 was used instead of AgNPs in the preparation of the AgNPs / MXene / Fe3O4 composite material. The specific preparation steps are as follows: The MXene / Fe3O4 composite material was dispersed in a 0.3 mol / L silver nitrate (AgNO3) solution, stirred at 400 rpm, and 1 mg / mL sodium phosphate solution was added to react and generate a uniformly loaded Ag3PO4 / MXene / Fe3O4 composite material. The remaining steps are the same as in Example 1.

[0142] Comparative Example 10:

[0143] Difference from Example 1: In the preparation of the multifunctional nanocomposite material of MXene / Fe3O4 / AgNPs in this comparative example, the polyacrylonitrile (PAN) solution was replaced with polyethylene oxide, and the multifunctional nanocomposite material of MXene / Fe3O4 / AgNPs was prepared by loading Fe3O4 and AgNPs and electrospinning according to steps (1)-(4) of Example 1.

[0144] Test Example 1 Antibacterial Effect

[0145] Test subjects: different membrane materials prepared in Examples 1-7 and Comparative Examples 1-10.

[0146] Tested bacterial species: Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus.

[0147] Test conditions: The initial concentration of E. coli bacterial suspension was 3×10⁻⁶. 7The concentration of bacteria was CFU / mL, the solution volume was 50 mL, and the material dosage was 0.4 g / L. The bacterial concentrations before and after the experiment were obtained using the plate count method, and the results were compared to obtain the final test results.

[0148] Table 1. Test results of different membrane materials in removing Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus.

[0149]

[0150]

[0151] The antibacterial test results in the table show that the composite materials in the examples all exhibit excellent antibacterial properties, with a bactericidal rate of over 98%, but there are some differences. By comparing different examples and comparative examples, it can be revealed that the antibacterial properties of the materials are affected by a variety of factors, including the material composition, the loading of nanoparticles, and the preparation process.

[0152] First, by comparing Example 1 and Comparative Example 1, it can be seen that the addition of MXene significantly improves the antibacterial performance. In Example 1, the synergistic effect of MXene, Fe3O4, and AgNPs resulted in antibacterial efficacy of 99.2% (Pseudomonas aeruginosa) and 98.9% (methicillin-resistant Staphylococcus aureus), while in Comparative Example 1, due to the absence of MXene, the antibacterial performance decreased to 84.50% and 81.80%. This indicates that MXene not only provides a good carrier structure in the composite material, but its unique two-dimensional layered structure and high conductivity also promote the antibacterial activity of AgNPs.

[0153] In Example 2, replacing Ti2AlC2 with Nb2AlC altered the conductivity of MXene and the loading capacity of silver nanoparticles, thus affecting the conductivity and antibacterial effect of the composite material. Compared to Example 1, the results showed a decrease in the antibacterial effect of the composite material.

[0154] The antibacterial effect of Example 3 was superior to that of Comparative Example 7, mainly due to the different etchant compositions used in the two examples. Example 3 used a mixed solution of 9M hydrochloric acid (HCl) and 1 g / mL sodium fluoride (NaF) as the etchant, while Comparative Example 7 used a mixed solution of 9M hydrochloric acid (HCl) and 1 g / mL lithium fluoride (LiF). NaF provides sufficient fluoride ions (F-), thereby promoting efficient etching of aluminum, a characteristic that makes it very suitable for the preparation of MXene. In contrast, LiF has lower solubility and provides insufficient fluoride ion concentration, resulting in a slower reaction rate and poorer etching effect. Therefore, NaF exhibits superior applicability in the etching process of MXene, which is the key factor contributing to the better antibacterial effect of Example 3.

[0155] In Example 4, by adjusting Fe 3+ with Fe 2+ The molar ratio was 2.2:1, which increased the amount of Fe. 3+ The ratio of Fe3O4 particles was affected, which in turn affected the catalytic activity. Therefore, the antibacterial effect of the composite material was slightly lower than that of Example 1.

[0156] In Example 5, ascorbic acid has a strong reducing ability and can quickly generate smaller AgNPs. However, this reduction reaction may result in poor dispersion of silver particles, which leads to a slightly lower antibacterial effect of the composite material compared to Example 1.

[0157] In Example 6, increasing the silver nanoparticle loading actually resulted in a lower antibacterial effect than in Example 1. This may be due to silver nanoparticle aggregation, excessive silver ion release, or saturation of the antibacterial effect, leading to a decrease in the overall antibacterial efficacy. In contrast, Example 3, which used different etchants (HCl / NaF) to prepare MXene, showed a slight decrease in antibacterial efficacy, at 88.5% and 89.3%. This is because different etching methods affect the surface structure and interlayer spacing of MXene, and the different ions carried by different etchants affect the electrochemical properties of MXene, thus impacting the material's antibacterial performance.

[0158] In Comparative Example 2, the removal of AgNPs resulted in a significant decrease in antibacterial performance, reaching only 59.0% and 57.5%. AgNPs play a crucial role in the antibacterial mechanism; the released silver ions can directly disrupt the bacterial cell wall, playing a major antibacterial role. In Example 5, although the reducing power of ascorbic acid was not as high as that of polydopamine, the material still exhibited an antibacterial effect of over 98%, indicating that a suitable preparation process can ensure a certain loading of silver nanoparticles, thereby maintaining the antibacterial activity of the material.

[0159] Comparing Example 7 and Example 1, it was found that the type of matrix material had little impact on antibacterial properties. Replacing polyacrylonitrile (PAN) with polycaprolactone (PCL) slightly reduced the antibacterial effect, but it still remained at 98.9% and 98.6%.

[0160] In Comparative Example 6, replacing MXene with TiO2 significantly reduced the antibacterial effect, to only 76.7% and 75.9%. This may be because TiO2 has weaker antibacterial activity under no-light conditions, while MXene has excellent conductivity and a high specific surface area, which can more effectively support the antibacterial effect of AgNPs.

[0161] The pure PAN fiber membrane (Comparative Example 5) had almost no antibacterial effect, with a bactericidal rate of only 4.0% and 3.8%, indicating that the matrix material itself contributed very little to the antibacterial performance and mainly relied on the functionality of the nanoparticles.

[0162] The antibacterial effect of Comparative Example 8 was significantly lower than that of Example 1, but higher than that of Comparative Example 3 without Fe3O4 loading. This is mainly due to the high proportion of Fe. 3+ It may inhibit the catalytic efficiency of the composite material, thereby affecting its antibacterial properties.

[0163] The antibacterial effect of Comparative Example 9 was much lower than that of Example 1, but better than that of Comparative Example 2 without nano-silver loading. Surface-loaded nano-silver exhibited significantly better antibacterial effects than Ag3PO4 in this material.

[0164] The antibacterial effect of Comparative Example 10 was significantly lower than that of Example 1. This is because PEO has lower mechanical strength, poorer electrical conductivity, and higher solubility, which may lead to uneven loading and release of silver nanoparticles and Fe3O4, thereby reducing the antibacterial efficacy of the material.

[0165] Test Example 2: Antibiotic Degradation Effect

[0166] Test subjects: Materials prepared in Examples 1-7 and Comparative Examples 1-10.

[0167] Antibiotics tested: sulfamethoxazole, ofloxacin.

[0168] A 300W xenon lamp equipped with an ultraviolet cutoff filter (>420nm) was used as the light source to ensure that only visible light was provided. 10 mg of the materials from Examples 1-7 and Comparative Examples 1-8 were added to 50 mL of an aqueous solution containing sulfamethoxazole (5 mg / L), and the mixture was magnetically stirred in the dark for 30 minutes to reach adsorption-desorption equilibrium of the materials and contaminants. The lamp was then turned on for irradiation. During irradiation, 1 mL of the reaction solution was extracted periodically and filtered through a 0.22 μm polyethersulfone (PES) membrane to obtain the supernatant. The remaining sulfamethoxazole and ofloxacin concentrations were measured using ultra-high performance liquid chromatography (HPLC).

[0169] Table 2. Test results of antibiotic degradation by different materials

[0170] Example 1 92.50％ 88.50％ Example 2 90.80％ 85.80％ Example 3 89.40％ 84.10％ Example 4 91.70％ 87.00％ Example 5 87.50％ 82.50％ Example 6 90.30％ 84.00％ Example 7 90.50％ 86.20％ Comparative Example 1 76.40％ 72.50％ Comparative Example 2 63.20％ 58.50％ Comparative Example 3 58.10％ 54.00％ Comparative Example 4 22.13％ 20.30％ Comparative Example 5 4.50％ 3.70％ Comparative Example 6 70.30％ 65.10％ Comparative Example 7 84.20％ 79.80％ Comparative Example 8 78.50％ 73.90％ Comparative Example 9 77.40％ 69.30％ Comparative Example 10 78.70％ 71.50％

[0171] A comparison of Example 1 and Comparative Example 1 shows that the addition of MXene in Example 1 significantly improved the degradation efficiency of sulfamethoxazole and ofloxacin. MXene not only provides abundant active sites, promoting the adsorption of pollutants, but also enhances the transfer of photogenerated electrons, thereby reducing electron-hole pair recombination. This mechanism enabled Example 1 to show significantly better performance than Comparative Example 1 in degrading both antibiotics. Although the degradation efficiency of ofloxacin was slightly lower than that of sulfamethoxazole, MXene also enhanced the degradation performance of ofloxacin.

[0172] In Example 1, the introduction of MXene significantly improved the degradation efficiency of sulfamethoxazole and ofloxacin, far exceeding the degradation effect of TiO2 in Comparative Example 5. Although TiO2 performed well under ultraviolet light irradiation, its photocatalytic activity was weak under visible light. MXene not only absorbs more visible light but also provides a better electron transport pathway, thereby enhancing the photocatalytic degradation effect. The degradation efficiency of the two antibiotics in Example 1 was significantly better than that of the TiO2 control group, especially the degradation effect of ofloxacin was also significantly improved.

[0173] In the comparison between Example 6 and Example 1, although the loading of AgNPs was increased in Example 6, the degradation efficiency was lower than that in Example 1. This may be because excessive silver nanoparticles caused them to aggregate, reducing the effective surface area and photocatalytic activity. Simultaneously, excessive silver particles may have increased electron-hole pair recombination, reducing photocatalytic efficiency. Furthermore, excessive silver nanoparticles may have affected the uniform distribution of light, reducing the effective utilization of light. Therefore, although increasing AgNPs generally improves degradation efficiency, excessive use may actually lead to a decrease in degradation efficiency due to problems such as aggregation and recombination.

[0174] In Example 4, the presence of AgNPs significantly improved the degradation efficiency of sulfamethoxazole and ofloxacin. In contrast, Comparative Example 2, which removed AgNPs, resulted in a substantial decrease in degradation efficiency. AgNPs can effectively generate reactive oxygen species (such as hydroxyl radicals and peroxide anions), which are important driving forces for photocatalytic degradation. The significantly reduced degradation efficiency of the two antibiotics in Comparative Example 2 indicates that AgNPs play a crucial role in improving photocatalytic degradation performance.

[0175] In Comparative Example 3, only AgNPs were loaded onto the MXene surface without in-situ loading of Fe3O4. The test results showed that the degradation rates of sulfamethoxazole and ofloxacin were 58.10% and 54.00%, respectively, which were much lower than those in Example 1 (92.50% and 88.50%, respectively). This indicates that the participation of Fe3O4 not only provides enzyme-like catalytic activity but also promotes electron transfer and reduces electron-hole recombination, thereby significantly improving the overall degradation efficiency. In Comparative Example 4, when only Fe3O4 nanoparticles were used without the participation of MXene and AgNPs, the degradation rates were only 22.13% and 20.30%, respectively. This shows that the photocatalytic activity of Fe3O4 alone under visible light conditions is limited and it is difficult to effectively generate reactive oxygen species, thus verifying the importance of the synergistic effect of multiple components. Furthermore, Comparative Example 7 used a polymer matrix different from that of Example 1, with degradation rates of 84.20% and 79.80%, respectively. Although these were relatively high, they were still lower than those of Example 1, which used a PAN matrix. This indicates that the polymer matrix has a significant impact on the dispersibility, light absorption, and carrier transport of the composite material, and failed to achieve the optimal synergistic effect of MXene / Fe3O4 / AgNPs in the PAN matrix.

[0176] In Comparative Example 8, Fe was... 3+ with Fe 2+ After adjusting the molar ratio to 4:1, the test results showed that the degradation rates of sulfamethoxazole and ofloxacin were 78.50% and 73.90%, respectively. This indicates that excessive Fe... 3+ The ratio may cause changes in the morphology and size of the generated Fe3O4 particles, thereby affecting their catalytic activity and electron transport efficiency, reducing the overall degradation effect, and further verifying the importance of maintaining Fe... 3+ / Fe 2+ The optimal molar ratio (e.g., 1.8:1) is crucial for achieving efficient catalysis. Meanwhile, Comparative Example 9 used Ag3PO4 instead of AgNPs generated through polydopamine reduction, with degradation rates of 77.40% and 69.30%. Although Ag3PO4 itself possesses some photocatalytic activity, its degradation efficiency was significantly lower than that of the AgNPs system. This indicates that in this composite material, AgNPs are more conducive to the generation and transfer of photogenerated electrons, thereby producing reactive oxygen species and achieving higher degradation efficiency. Furthermore, Comparative Example 10 used other polymer matrices instead of PAN, with degradation rates of 78.70% and 71.50%, respectively. This further demonstrates that the polymer matrix has a significant impact on the structural stability, dispersibility, and photocatalytic performance of the composite material, and that PAN is more conducive to the uniform dispersion and synergistic action of MXene, Fe3O4, and AgNPs, thus significantly improving the photocatalytic degradation effect.

[0177] These comparisons reveal that the synergistic effect of MXene, AgNPs, and Fe3O4 is crucial for the photocatalytic degradation of sulfamethoxazole. MXene excels in enhancing electron transfer and adsorption capacity during the photocatalytic reaction, AgNPs are the core photocatalytic component generating reactive oxygen species, and Fe3O4 further improves the overall degradation efficiency through its nanozyme properties and synergistic photocatalytic effect. Furthermore, the uniform dispersion and appropriate loading of each component during material preparation significantly influence the photocatalytic effect. By rationally designing and optimizing the synergistic combination of photocatalytic components, the degradation efficiency of antibiotics can be significantly improved, providing an efficient solution for the treatment of environmental pollutants.

[0178] Test Example 3 Security Test

[0179] Test subjects: Materials from Examples 1-8.

[0180] Test item: CCK-8 assay for the cytotoxicity of composite materials

[0181] Test conditions:

[0182] Using L929 fibroblasts as a model, the cells were 10 4 Cells were seeded per well in 96-well plates and incubated at 37°C and 5% CO2 for 24 hours. Sample solutions of 10, 50, and 100 μg / mL were added to each well, with three replicates. A control group (containing no sample) was also included. After treatment, 10 μL of CCK-8 reagent was added to each well, and the cells were incubated for 2 hours. The OD value was measured at 450 nm using a microplate reader, and cell viability was calculated using a formula. Throughout the experiment, samples were ensured to be uniformly dispersed, and the experiment was repeated three times to guarantee the reliability of the results.

[0183] Table 3. Survival rate of L929 fibroblasts under different concentrations of sample solution treatment.

[0184]

[0185]

[0186] Test results showed that the cell viability of Examples 1 to 8 at concentrations of 10, 50, and 100 μg / mL ranged from 91.3% to 96.2%, exhibiting low cytotoxicity and good biocompatibility. Cell viability decreased slightly with increasing concentration, but the decrease was not significant, indicating a weak concentration-dependent toxicity. Example 6 showed the highest cell viability at all concentrations (up to 96.2%), demonstrating the best toxicity control. Overall, all samples met the safety requirements for biomaterials and are suitable for further research and application.

[0187] Test Example 4: Recyclability Test

[0188] Test subjects: Materials from Examples 1-8.

[0189] Test items: antibacterial effect, antibiotic degradation effect.

[0190] Test conditions:

[0191] The antibacterial effect test conditions are the same as those for Test 1, and the antibiotic degradation effect test conditions are the same as those for Test 2. After each test, centrifuge and wash with distilled water, collect the precipitated particles and test again, repeating the cycle ten times.

[0192] Table 4. Antibacterial efficacy and antibiotic degradation performance of each embodiment after ten cycles.

[0193]

[0194] After ten cycles, all samples exhibited good stability. The antibacterial effect against *Pseudomonas aeruginosa* and *Staphylococcus aureus* maintained inhibition rates above 92%, and the antibiotic degradation efficiency ranged from 77.8% to 84.8%. Example 1 showed the best performance in both antibacterial efficacy and antibiotic degradation, with inhibition rates of 94.5% and 94.3%, respectively, and degradation efficiencies of 84.8% and 82.7%, respectively. This demonstrates excellent recyclability and material stability, making it suitable for further promotion in practical applications.

Claims

1. A method for preparing a multifunctional nanoenzyme composite material based on MXene, characterized in that, Includes the following steps: (1) An etchant was added to the MAX phase precursor and reacted. After the reaction was completed, MXene nanosheets were obtained. (2) The MXene nanosheets were dispersed in deionized water to obtain a suspension, and Fe was added to the suspension. 2+ and Fe 3+ The mixed solution was used to obtain a mixed liquid. The pH of the mixed liquid was adjusted to carry out the reaction. After the reaction was completed, the MXene / Fe3O4 composite material was obtained. (3) The MXene / Fe3O4 composite material was dispersed in silver nitrate solution, and a reducing agent was added to react. After the reaction was completed, AgNPs / MXene / Fe3O4 composite material was obtained. (4) The AgNPs / MXene / Fe3O4 composite material is mixed with a polymer solution to obtain a spinning solution; the spinning solution is spun into a film by electrospinning equipment to obtain a multifunctional nanoenzyme composite material based on MXene. The MAX phase precursor material includes at least one of Ti3AlC2, Ti2AlC, and Nb2AlC; The etchant includes at least one of hydrofluoric acid, hydrogen chloride and sodium fluoride mixed solution; In the Fe-containing 2+ and Fe 3+ In the mixed solution, Fe 3+ Fe 2+ The molar ratio ranges from 1.8:1 to 2.2:1; The polymer is at least one of polyacrylonitrile, polycaprolactone, and polyurethane; In the composite material, the mass ratio of MXene to Fe3O4 is 1:1-1:2, and the loading of AgNPs is 1%-10% of the total mass of the composite material.

2. The method for preparing a multifunctional nanoenzyme composite material based on MXene according to claim 1, characterized in that, In step (1), The reaction temperature is 20-45℃, and the reaction time is 12-24 h.

3. The method for preparing a multifunctional nanoenzyme composite material based on MXene according to claim 2, characterized in that, The concentration of the hydrofluoric acid is 10-40%; the mass ratio of hydrogen chloride to sodium fluoride in the mixed solution of hydrogen chloride and sodium fluoride is 6:

1.

4. The method for preparing a multifunctional nanoenzyme composite material based on MXene according to claim 1, characterized in that, In step (2), The concentration of MXene nanosheets in the suspension is 1-5 mg / mL; The Fe-containing 2+ and Fe 3+ In the mixed solution, Fe 3+ The concentration is 0.1-0.5 mol / L, Fe 2+ The concentration is 0.05-0.3 mol / L; The pH value of the mixture is 8-10; The pH adjuster of the mixture includes at least one of ammonia, sodium hydroxide, and sodium acetate; The reaction temperature is 40-60℃, and the reaction time is 1-2 hours.

5. The method for preparing a multifunctional nanoenzyme composite material based on MXene according to claim 1, characterized in that, In step (3), The concentration of the silver nitrate solution is 0.1-0.5 mol / L; The reducing agent includes at least one of ascorbic acid and polydopamine, wherein the molar ratio of ascorbic acid to silver nitrate is 1:10 to 1:2, and the molar ratio of polydopamine to silver nitrate is 1:100 to 1:50; the concentration of ascorbic acid is 10-50 mM, and the concentration of polydopamine is 0.5-2 mg / mL. The reaction temperature is 20-50℃, and the reaction time is 3-6 h.

6. The method for preparing a multifunctional nanoenzyme composite material based on MXene according to claim 1, characterized in that, In step (4), The polymer concentration in the polymer solution is 5-20 wt%; The mass ratio of the AgNPs / MXene / Fe3O4 composite material to the polymer solution is 1:10-2:10; The electrospinning equipment has a voltage of 10-20 kV, a distance of 15-20 cm between the power supply and the receiving plate, a flow rate of 0.5-1 mL / h for the injection pump, and a spinning temperature of 25-30℃.

7. A multifunctional nanoenzyme composite material based on MXene prepared by the preparation method according to any one of claims 1-6.

8. The application of the MXene-based multifunctional nanoenzyme composite material of claim 7 in the visible light photocatalytic degradation of visible light photocatalytic antibiotics in water, characterized in that, The antibiotic is one or more of sulfamethoxazole and ofloxacin.

Images