A MOFs derived copper-based composite membrane and a preparation method and application thereof

Abstract

The application provides a MOFs derived copper fiber composite film and a preparation method and application thereof, and comprises the following steps: (1) adding copper nitrate trihydrate and trimesic acid into a solvent 1 to obtain a MOFs precursor solution; (2) performing a solvothermal reaction on the MOFs precursor solution to obtain a HK solid; (3) dispersing the HK solid and polyacrylonitrile into a solvent 2 to obtain an electrospinning precursor solution; (4) performing electrospinning on the electrospinning precursor solution to obtain a fiber film HK-1 / PAN; (5) immersing the HK-1 / PAN into a solution containing copper nitrate trihydrate and trimesic acid to perform a solvothermal reaction, and obtaining HK-2 / PAN; and (6) pre-oxidizing and calcining the HK-2 / PAN to obtain a MOFs derived copper-based composite film. The application utilizes a secondary growth strategy to improve the loading amount and uniformity of MOFs particles on the fiber film, and to enhance the catalytic activity and conductivity thereof, and is used for visual detection and efficient degradation of PFOA.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalytic materials, and particularly relates to a MOFs-derived copper-based composite film for visual detection and degradation of perfluorooctanoic acid and a preparation method thereof. BACKGROUND

[0002] Perfluorooctanoic acid (PFOA) is difficult to be hydrolyzed, pyrolyzed and photolyzed in nature, and is transported to the earth's surface and soil through water circulation and atmospheric circulation, and then is accumulated in organisms through the food chain and is difficult to be discharged from the body through the excretion system, which has great harm to hormone secretion, immunity, gene expression and fetal development of human body. Therefore, it is very important to seek an economic and effective method for detecting and degrading PFOA for the environment and human health. The simulated enzyme colorimetric detection method can realize qualitative / quantitative detection of the substrate by constructing a nanomaterial to simulate the catalytic color development of a natural enzyme on a specific substrate, and has the advantages of convenience, high efficiency and low cost. The photo-electric Fenton degradation can obtain high-activity ·OH by in-situ generation of H2O2 through anodic oxidation and electrocatalytic decomposition by a Fenton-like catalyst; and the photo-oxidative decarboxylation reaction can promote the complexation of transition metal ions and PFOA to form short-chain carboxylic acids and decomposition, which is conducive to realizing efficient degradation of PFOA under environmentally friendly, economically feasible and easily controlled conditions.

[0003] The MOFs-derived copper-based fiber composite material has catalytic activity of peroxide mimetic enzyme and Fenton-like reagent, and is widely used in the fields of sensing and catalysis. The electrospinning technology combined with high-temperature carbonization is an effective technical means for preparing uniform and conductive MOFs-derived composite materials. Some researchers mix MOFs precursors and polymer precursors by using a simple and efficient “one-pot method”, obtain a spinning solution precursor by using an in-situ growth method, and then perform electrospinning and high-temperature carbonization (such as patent document CN 114875525), but the presence of the polymer can affect the controllable growth of the MOFs. Therefore, some researchers first prepare copper-based MOFs by using a solvothermal method, and then blend the MOFs with a spinning precursor to perform electrospinning and high-temperature carbonization (such as patent document CN 111081995), but the loading amount of metal particles is easily limited by the spinning conditions, and too high loading can reduce the applicability of the polymer solution, and it is difficult to obtain a continuous and dense MOFs fiber film. SUMMARY

[0004] In order to solve the above technical problems, the application provides a MOFs-derived copper fiber composite film and a preparation method and application thereof, which uses a “secondary growth” strategy to improve the loading amount and uniformity of MOFs particles on the fiber film, enhances the catalytic activity and conductivity of the copper-based fiber composite film, and endows the copper-based fiber composite film with excellent cycle stability, and is used for visual detection and efficient degradation of PFOA.

[0005] The application is achieved by the following technical solutions:

[0006] A preparation method of MOFs derived copper-based composite film, comprising the following steps:

[0007] (1) adding copper nitrate trihydrate and trimesic acid into solvent 1, mixing to obtain MOFs precursor solution;

[0008] (2) performing solvothermal reaction on the MOFs precursor solution, and washing, drying and activating the obtained product to obtain HK solid;

[0009] (3) dispersing the HK solid into solvent 2, adding polyacrylonitrile, stirring and heating to obtain electrospinning precursor solution;

[0010] (4) performing electrospinning on the electrospinning precursor solution to obtain fiber film HK-1 / PAN;

[0011] (5) immersing the HK-1 / PAN into a solution containing copper nitrate trihydrate and trimesic acid, and performing solvothermal reaction to obtain HK-2 / PAN;

[0012] (6) pre-oxidizing the HK-2 / PAN, and calcining under inert atmosphere at high temperature to obtain MOFs derived copper-based composite film.

[0013] Preferably, in step (1), the solvent 1 is a mixed solution of deionized water, anhydrous ethanol and N,N-dimethylformamide.

[0014] Preferably, in step (1), the mass ratio of copper nitrate trihydrate to trimesic acid is (3.5-7.0) g:(1.68-3.36) g; and in step (3), the mass ratio of HK solid to polyacrylonitrile is (1-2) g:(1-2) g.

[0015] Preferably, in step (2), the solvothermal reaction temperature is 110-130 DEG C, and the time is 11-13 h.

[0016] Preferably, in step (5), the solvothermal reaction temperature is 110-130 DEG C, and the time is 11-13 h.

[0017] Preferably, in step (6), the pre-oxidation temperature is 280-300 DEG C, and the high-temperature calcination temperature is 700-900 DEG C.

[0018] The MOFs derived copper-based composite film obtained by the preparation method.

[0019] The MOFs derived copper-based composite film is applied in PFOA visual detection, and the MOFs derived copper-based composite film is used as a simulated enzyme to detect PFOA by colorimetric detection method.

[0020] The MOFs derived copper-based composite film is used in the application of PFOA degradation.

[0021] Preferably, the PFOA is degraded by using a photo-electric Fenton technology.

[0022] Compared with the prior art, the application has the following beneficial effects:

[0023] The preparation method of the application converts the powdered catalyst into a flexible self-supporting flexible porous carbon nanofiber film through electrospinning technology, effectively improving the catalytic activity, recycling property and stability thereof; at the same time, the seed secondary growth strategy is used to effectively improve the loading amount and uniformity of Cu-MOFs particles on the PAN fiber film, and enrich the active sites; and through the high-temperature carbonization strategy, the reaction temperature is optimized, the Cu / C is dispersed and fixed on the polyacrylonitrile (PAN) derived 3D carbon fiber network, and the porous carbon composite material embedded with elemental copper or copper oxide is prepared, so that the copper nanoparticles can be highly dispersed in the entire carbon skeleton, and good conductivity is achieved.

[0024] The MOFs derived copper-based composite film has excellent peroxide mimic enzyme activity, and can be used for visual detection of PFOA; and the MOFs derived copper-based composite film exhibits encouraging performance in degradation of PFOA pollutants, has a wide and stable pH range, and has a high Cu 2+ / Cu + The MOFs derived copper-based composite film can be used as an efficient catalyst for photo-electric Fenton, and is used for degrading PFOA. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The SEM (a, b), XRD (c) and XPS (d) diagrams of the MOFs derived copper-based composite film prepared for Examples 1, 2, 3 and Comparative Example 1.

[0026] Figure 2 The enzyme activity (a) and PFOA detection performance (b) of the MOFs derived copper-based composite film prepared for Examples 1, 2 and 3.

[0027] Figure 3 The degradation rate of PFOA of the MOFs derived copper-based composite film prepared for Examples 1, 2, 3 and Comparative Example 2.

[0028] Figure 4 The degradation rate of PFOA of the MOFs derived copper-based composite film prepared for Example 2 at different pH values. DETAILED DESCRIPTION

[0029] For a further understanding of the present application, the application will be described in greater detail below with reference to the embodiments. These descriptions are only to further explain the features and advantages of the present application, and are not intended to limit the claims of the present application.

[0030] The preparation method of the MOFs derived copper-based composite film comprises the following steps:

[0031] (1) dispersing copper nitrate trihydrate (Cu(NO3)2·3H2O) and benzene-1,3,5-tricarboxylic acid (H3BTC) into a mixed solution (deionized water: anhydrous ethanol: N,N-dimethylformamide (DMF) = 1:1:1, V / V / V) respectively, and mixing to obtain a MOFs precursor solution;

[0032] (2) transferring the MOFs precursor solution to a polytetrafluoroethylene reaction liner, sealing, and performing a solvothermal reaction at a reaction temperature of 110-130℃ for 11-13h; after the reaction is completed, natural cooling, washing with the above-mentioned mixed solution, centrifugation and drying to obtain a solid HKUST-1 (HK);

[0033] (3) dispersing the HK solid into DMF after being fully ground, ultrasonicating, adding polyacrylonitrile (PAN), and magnetically stirring at 60-70℃ for 10-12h to obtain an electrospinning precursor solution;

[0034] (4) transferring the above-mentioned electrospinning precursor solution into a plastic syringe and clamping it on a support frame, wrapping aluminum foil on a roller to collect nanofibers, controlling the voltage, the feeding speed and the distance between the needle and the collector, and electrospinning to obtain a fiber film (HK-1 / PAN);

[0035] (5) dispersing and dissolving copper nitrate trihydrate and benzene-1,3,5-tricarboxylic acid into anhydrous ethanol respectively, then stirring after mixing, pouring into a reaction kettle liner, cutting the fiber film HK-1 / PAN into a suitable size, vertically inserting into the reaction kettle liner to perform a solvothermal reaction, and secondarily growing to obtain HK-2 / PAN;

[0036] (6) placing the pre-oxidized HK-2 / PAN into a tube furnace and high-temperature calcining under N2 atmosphere to obtain a MOFs derived copper-based composite film.

[0037] The present application selects solvents, and the selection of the solvents is related to the stability of the PAN film. The second growth of the MOF adopts ethanol, and if DMF is added as the solvent, the PAN film will be broken down under the solvothermal condition; and if ethanol is directly used as the solvent in step 1, the dispersibility of the HK in step 3 is poor, resulting in that the composite film obtained in step 4 is very poor in uniformity.

[0038] In step (1), the mass ratio of copper nitrate trihydrate and trimesic acid is (3.5-7.0) g:(1.68-3.36) g; in step (3), the mass ratio of HK solid and polyacrylonitrile is (1-2) g:(1-2) g.

[0039] In steps (2) and (5), the solvent thermal reaction temperature is 110-130 DEG C, and the time is 11-13 h.

[0040] In step (6), the pre-oxidation temperature is 280-300 DEG C, and the high-temperature calcination temperature is 700-900 DEG C.

[0041] The application is based on the simulation enzyme characteristics of MOFs derived copper-based composite film to construct a copper-based visual detection system and is used for visual detection of PFOA.

[0042] The application uses MOFs derived copper-based composite film as a cathode to construct a copper-based solar-electric Fenton system (Cu-SPEF) and is used for efficient degradation of PFOA.

[0043] Example 1:

[0044] A kind of MOFs derived copper-based composite film preparation, comprising the following steps:

[0045] a, deionized water, anhydrous ethanol, DMF are mixed according to 1:1:1 to obtain solution A. 3.5g Cu (NO3) 2·3H2O and 1.68g H3BTC are dispersed into solution A to obtain solution B and solution C, then solution B is poured into solution C and mixed uniformly to obtain solution D.

[0046] b, solution D is transferred to a polytetrafluoroethylene reaction liner, sealed, 100 DEG C solvent thermal reaction 12h, cooling, centrifugation. After washing and centrifugation with the above solution A, 80 DEG C drying, HK solid is obtained.

[0047] c, 1g HK solid is dispersed into DMF after grinding, ultrasonic, 1g polyacrylonitrile is added, 65 DEG C magnetic stirring 12h to obtain solution E.

[0048] d, solution E is transferred to a 10cm plastic syringe with a 23 gauge needle and clamped on a support frame. Aluminum foil is wrapped on the roller (300rpm / min) to collect nanofibers, the control voltage is 14kv, the feeding speed is 0.8mm / min -1 , the distance between the needle and the collector is 15cm, and electrospinning is carried out to obtain a fiber membrane (HK-1 / PAN).

[0049] e、1.75g Cu(NO3)2·3H2O and 0.84g H3BTC were dispersed and dissolved into 50mL anhydrous ethanol respectively, then poured into the inner liner of the reactor after stirring and mixing, the fiber membrane HK-1 / PAN was cut into 4x4cm 2 , inserted vertically into the inner liner of the reactor, and solvent thermal reaction was carried out at 120℃ for 12h, then washed with methanol, activated after cooling to room temperature, and then vacuum dried at 70℃ to obtain HK-2 / PAN.

[0050] f、The HK-2 / PAN membrane was placed in a tube furnace, and the temperature was raised to 280℃ at a rate of 2℃ / min for pre-oxidation. It was re-placed in the tube furnace, and the temperature was raised to 700℃ at a rate of 2℃ / min, and kept for 1h to obtain MOFs derived copper-based composite membrane (CNF-Cu / C-700).

[0051] Enzyme activity test: 8mg MOFs derived copper-based composite membrane was added to 9mL B-R buffer solution (pH=4), then 500μL TMB (10mM) and 500μL H2O2 (60mM) were added, and the UV-Vis spectrum of 500-800nm was tested by ultraviolet spectrophotometer after reaction at 45℃ for 10min.

[0052] Degradation test: 2x2cm 2 MOFs derived copper-based composite membrane was used as the cathode, 2x2cm 2 platinum sheet was used as the anode, and 20mg L -1 PFOA solution was used as the electrolyte. The working electrode was irradiated by a 300W xenon lamp, and a direct current of 100mA was applied for solar- electro Fenton degradation experiment. O2 was continuously introduced during the reaction.

[0053] Example 2:

[0054] A preparation and application of a MOFs derived copper-based composite membrane, comprising the following steps:

[0055] a、Deionized water, anhydrous ethanol and DMF were mixed in a ratio of 1:1:1 to obtain solution A. 3.5g Cu(NO3)2·3H2O and 1.68g H3BTC were dispersed in solution A respectively to obtain solution B and solution C, then solution B was poured into solution C, and mixed uniformly to obtain solution D.

[0056] b、Solution D was transferred to a polytetrafluoroethylene reaction liner, sealed, and solvent thermal reaction was carried out at 100℃ for 12h, then cooled and centrifuged. After washing and centrifuging with the above-mentioned solution A for several times, HK solid was obtained by drying at 80℃.

[0057] c. 1 g of HK solid was ground thoroughly and dispersed in DMF, ultrasonic, 1 g of PAN was added, a solution E was obtained after 12 h of magnetic stirring at 65 °C.

[0058] d. Solution E was transferred into a 10 cm plastic syringe with a 23 gauge needle and clamped to a support frame. Aluminum foil was wrapped around the drum (300 rpm / min) to collect the nanofibers, with a voltage of 14 kv, a feeding speed of 0.8 mm / min, a distance of 15 cm between the needle and the collector, and electrospinning to obtain a fiber membrane (HK-1 / PAN). -1

[0059] e. 1.75 g of Cu(NO3)2·3H2O and 0.84 g of H3BTC were respectively dispersed and dissolved in 50 mL of anhydrous ethanol, then after stirring, poured into the inner liner of the reaction kettle, the fiber membrane HK-1 / PAN was cut into 4 x 4 cm 2 , vertically inserted into the inner liner of the reaction kettle, and solvent thermal reaction was carried out at 120 °C for 12 h. After cooling to room temperature, it was washed, activated with methanol, and then vacuum dried at 70 °C to obtain HK-2 / PAN.

[0060] f. The HK-2 / PAN membrane was placed in a tube furnace, pre-oxidized by increasing the temperature to 280 °C at a rate of 2 °C / min. It was re-placed in the tube furnace, and the temperature was increased to 800 °C at a rate of 2 °C / min, and kept for 1 h to obtain a MOFs-derived copper-based composite membrane (CNF-Cu / C-800).

[0061] Enzyme activity test: 8 mg of MOFs-derived copper-based composite membrane was added to 9 mL of B-R buffer solution (pH = 4), and then 500 μL of TMB (10 mM) and 500 μL of H2O2 (60 mM) were added. After 10 min of reaction at 45 °C, the ultraviolet-visible spectrum of 500-800 nm was tested by ultraviolet spectrophotometer.

[0062] Degradation test: 2 x 2 cm 2 MOFs-derived copper-based composite membrane was used as the cathode, and a 2 x 2 cm 2 platinum sheet was used as the anode. H2SO4-Na2SO4 buffer solution (0.05 M, pH = 2-8) was used to configure the electrolyte (PFOA, 20 mg / L -1 ). A 300 W xenon lamp was used to irradiate the working electrode, and a direct current of 100 mA was applied for solar-photocatalytic Fenton degradation experiment. O2 was continuously introduced during the reaction.

[0063] Example 3:

[0064] A MOFs-derived copper-based composite membrane was prepared, comprising the following steps:

[0065] ​a. Deionized water, anhydrous ethanol, DMF were mixed in 1:1:1 to obtain solution A. 3.5 g Cu(NO3)2·3H2O and 1.68 g H3BTC were dispersed in solution A to obtain solution B and solution C, respectively, and then solution B was poured into solution C to obtain solution D.

[0066] b. Solution D was transferred to a polytetrafluoroethylene reaction liner, sealed, and solvent-thermal reacted at 100°C for 12 h, cooled, and centrifuged. After being washed with the above mixed solution for several times, the centrifuged product was dried at 80°C to obtain HK solid.

[0067] c. 1 g of HK solid was ground and dispersed in DMF, ultrasonicated, and 1 g of PAN was added to obtain solution E after magnetic stirring at 65°C for 12 h.

[0068] d. Solution E was transferred to a 10 cm plastic syringe with a 23 gauge needle and clamped on a support frame. Aluminum foil was wrapped on the roller (300 rpm / min) to collect nanofibers, with a voltage of 14 kv, a feeding speed of 0.8 mm / min, a distance of 15 cm between the needle and the collector, and electrospinning to obtain a fiber membrane (HK-1 / PAN). -1

[0069] e. 1.75 g of Cu(NO3)2·3H2O and 0.84 g of H3BTC were dispersed and dissolved in anhydrous ethanol, and then mixed and stirred before being poured into the reaction kettle liner. The fiber membrane HK-1 / PAN was cut into 4×4 cm 2 , vertically inserted into the reaction kettle liner, and solvent-thermal reacted at 120°C for 12 h. After cooling to room temperature, the product was washed with methanol, activated, and then vacuum dried at 70°C to obtain HK-2 / PAN.

[0070] f. The HK-2 / PAN membrane was placed in a tube furnace, pre-oxidized by increasing the temperature to 280°C at a rate of 2°C / min, and then placed back in the tube furnace and heated to 900°C at a rate of 2°C / min, and kept at this temperature for 1 h to obtain MOFs-derived copper-based composite membrane (CNF-Cu / C-900).

[0071] Enzyme activity test: 8 mg of MOFs-derived copper-based composite membrane was added to 9 mL of B-R buffer solution (pH = 4), and then 500 μL of TMB (10 mM) and 500 μL of H2O2 (60 mM) were added. After reacting at 45°C for 10 min, the ultraviolet-visible spectrum of 500-800 nm was tested by ultraviolet spectrophotometer.

[0072] Degradation test: 2×2 cm 2 MOFs-derived copper-based composite membrane was used as the cathode, and a 2×2 cm 2 platinum sheet was used as the anode, and 20 mg / L of 0.05 M H2SO4-Na2SO4 (pH = 3) electrolyte solution was prepared.​-1 PFOA solution was used as the electrolyte. A solar-electric Fenton degradation experiment was conducted by irradiating the working electrode with a 300W xenon lamp and applying a 100mA DC current, with O2 continuously introduced during the reaction.

[0073] Comparative Example 1:

[0074] No secondary seed growth is performed, i.e. step e is omitted in Example 2, and other conditions are the same as in Example 2.

[0075] Comparative Example 2:

[0076] High-temperature calcination is not performed, i.e. step f is omitted in Example 2, and other conditions are the same as in Example 2.

[0077] The present invention tested and obtained the physicochemical properties of the MOFs-derived copper-based composite films in Examples 1-3 and Comparative Example 1. Figure 1 Enzyme activity and PFOA detection performance of composite membranes in Examples 1-3 Figure 2 The degradation performance of PFOA by the composite membranes of Examples 1-3 and Comparative Example 2 () Figure 3 The degradation performance of the composite membrane in Example 2 under different pH conditions.

[0078] like Figure 1 As shown in Example 1, a small number of Cu MOF particles in the MOF-derived copper-based composite film are loaded into a PAN-derived carbon nanofiber network. This contrasts with Example 2. Figure 1 (b) After secondary seed growth, the number of octahedral CuMOF particles exposed on the fiber surface significantly increased and the loading was uniform. The MOF-derived copper-based composite film showed obvious derivation peaks at 2θ = 43.67°, 50.79°, and 74.29°, consistent with the standard diffraction card (PDF#04-0836), belonging to Cu(111), Cu(200), and Cu(220), respectively (Figure c). A weak diffraction peak of Cu2O was observed at 2θ = 36.8°. When the temperature exceeded 900℃, many other diffraction peaks belonging to CuO and Cu2O appeared. Combining with Figure d, the characteristic peaks at 952.6 eV and 932.8 eV belonged to CuO, respectively. + or Cu 0 Cu 2p 1 / 2 and Cu2p 3 / 2 The orbitals indicate that Cu exists primarily in zero- and monovalent forms, consistent with the XRD results. This demonstrates the presence of Cu metal nodes in MOFs. 2+ Reduced to Cu + and Cu 0 It is embedded in organic ligand-derived octahedral porous carbon materials.

[0079] like Figure 2As shown in Figure 8, the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes at different pyrolysis temperatures was compared. The experimental results showed that the catalytic activity of the composite membrane prepared at 800°C in Example 2 was the best. Based on the inhibitory effect of PFOA on the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes, the MOFs derived copper-based composite membrane in Example 2 was used to construct an efficient and sensitive PFOA visual detection system, and the linear response range was 1-50 μM, and the detection limit was 0.133 μM. Figure 2 b).

[0080] The test conditions for PFOA visual detection in the present application were as follows: 8 mg of MOFs derived copper-based composite membrane and 500 μL of PFOA with a series of concentrations were added to 8.5 mL of B-R buffer solution (pH = 4), and incubated at 45°C for 30 min. Then, 500 μL of TMB (0.5 mM) and 500 μL of H2O2 (3 mM) were added, and further reacted for 10 min. The absorbance value at 652 nm was measured.

[0081] As shown in Figure 8, the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes at different pyrolysis temperatures was compared. The experimental results showed that the catalytic activity of the composite membrane prepared at 800°C in Example 2 was the best. Based on the inhibitory effect of PFOA on the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes, the MOFs derived copper-based composite membrane in Example 2 was used to construct an efficient and sensitive PFOA visual detection system, and the linear response range was 1-50 μM, and the detection limit was 0.133 μM. Figure 3 As shown in Figure 8, the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes at different pyrolysis temperatures was compared. The experimental results showed that the catalytic activity of the composite membrane prepared at 800°C in Example 2 was the best. Based on the inhibitory effect of PFOA on the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes, the MOFs derived copper-based composite membrane in Example 2 was used to construct an efficient and sensitive PFOA visual detection system, and the linear response range was 1-50 μM, and the detection limit was 0.133 μM.

[0082] As shown in Figure 8, the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes at different pyrolysis temperatures was compared. The experimental results showed that the catalytic activity of the composite membrane prepared at 800°C in Example 2 was the best. Based on the inhibitory effect of PFOA on the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes, the MOFs derived copper-based composite membrane in Example 2 was used to construct an efficient and sensitive PFOA visual detection system, and the linear response range was 1-50 μM, and the detection limit was 0.133 μM. Figure 4 As shown in Figure 8, the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes at different pyrolysis temperatures was compared. The experimental results showed that the catalytic activity of the composite membrane prepared at 800°C in Example 2 was the best. Based on the inhibitory effect of PFOA on the peroxide mimic enzyme activity of MOFs derived copper-based composite membranes, the MOFs derived copper-based composite membrane in Example 2 was used to construct an efficient and sensitive PFOA visual detection system, and the linear response range was 1-50 μM, and the detection limit was 0.133 μM.

Claims

1. A method for preparing a MOF-derived copper-based composite film, characterized in that, Includes the following steps: (1) Add copper nitrate trihydrate and pyromellitic acid to solvent 1 and mix to obtain MOF precursor solution; solvent 1 is a mixed solution of deionized water, anhydrous ethanol and N,N-dimethylformamide; (2) The MOF precursor solution was subjected to a solvothermal reaction, and the resulting product was washed, dried and activated to obtain HK solid; (3) HK solid was dispersed in solvent 2, polyacrylonitrile was added, and the mixture was stirred and heated to obtain electrospinning precursor solution; (4) Electrospinning the electrospinning precursor solution to obtain the fiber membrane HK-1 / PAN; (5) HK-1 / PAN was immersed in a solution containing copper nitrate trihydrate and pyromellitic acid to carry out a solvothermal reaction to obtain HK-2 / PAN; (6) After HK-2 / PAN is pre-oxidized, it is calcined at high temperature in an inert atmosphere to obtain MOFs-derived copper-based composite film; wherein the pre-oxidation temperature is 280~300℃ and the high-temperature calcination temperature is 700-900℃.

2. The method for preparing MOFs-derived copper-based composite films according to claim 1, characterized in that, In step (1), the mass ratio of copper nitrate trihydrate to trimesic acid is (3.5~7.0) g : (1.68~3.36) g; in step (3), the mass ratio of HK solid to polyacrylonitrile is (1~2) g : (1~2) g.

3. The method for preparing MOFs-derived copper-based composite films according to claim 1, characterized in that, In step (2), the solvothermal reaction temperature is 110~130℃ and the time is 11~13 h.

4. The method for preparing MOFs-derived copper-based composite films according to claim 1, characterized in that, In step (5), the solvothermal reaction temperature is 110~130℃ and the time is 11~13 h.

5. MOFs-derived copper-based composite films obtained by the preparation method according to any one of claims 1-4.

6. The application of the MOFs-derived copper-based composite film as described in claim 5 in the visual detection of PFOA, characterized in that, The MOF-derived copper-based composite membrane was used as a mimic enzyme to detect PFOA using a colorimetric method.

7. The application of the MOFs-derived copper-based composite membrane according to claim 5 in PFOA degradation.

8. The application according to claim 7, characterized in that, Photo-electro-based Fenton technology was used to degrade PFOA.

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