Method for efficiently adsorbing and catalytically degrading PFOA (perfluorooctanoic acid) by using double-monatomic material

Abstract

The invention discloses a method for efficiently adsorbing and catalytically degrading PFOA (perfluorooctanoic acid) by using a double-monatomic material. The preparation method comprises the following specific steps: dissolving 3.94 g of 2-methylimidazole in 150 mL of methanol to prepare a solution A, mixing the solution A with 150 mL of a methanol solution B containing 3.39 g of Zn (NO3) 2.6 H2O and 80 mg of Fe (NO3) 3.9 H2O, heating to 60 DEG C from room temperature in a coating water bath, statically growing for 12 hours, and stirring for 12 hours; and centrifuging, washing with methanol, and carrying out vacuum drying at 60 DEG C for 12 hours to obtain a ZIF-8 precursor. Taking 150 mg of the precursor, dispersing the precursor in 18 mL of n-hexane, carrying out ultrasonic treatment for 70 minutes, dropwise adding 210 [mu] L of Ni (NO3) 2 methanol solution (25 mg / mL), stirring for 2 hours, carrying out centrifugal washing, and carrying out vacuum drying at 60 DEG C overnight; and finally, raising the temperature to 1000 DEG C at the speed of 10 DEG C / min in an Ar atmosphere, and calcining for 1 hour to obtain the NiFe catalyst. According to the material, an electron transfer path is optimized by regulating a double-monatomic coordination microenvironment, more than 80% of PFOA can be adsorbed and degraded within 10 minutes at normal temperature, and the removal rate within 2 hours is nearly 100%. The method can be used for preparing other double-monatomic catalysts in an expanded manner, and an efficient catalytic material is provided for wastewater treatment.

Description

Technical Field

[0001] The present invention belongs to the field of catalytic technology, and particularly relates to a preparation method for efficiently adsorbing and catalytically degrading PFOA materials by regulating the coordination microenvironment of dual single-atom active sites and optimizing the electron co-transfer path of metal centers in a catalyst. Background Art

[0002] Perfluorooctanoic acid (PFOA) is a new type of artificially synthesized fluorinated organic acid. Due to the presence of highly electronegative, small-sized fluorine atoms, strong polarity, and high bond energy (116 kcal / mol) carbon-fluorine bonds, PFOA has thermal stability, chemical stability, and hydrophobic and oleophobic properties in the environment. Therefore, it is widely used in industrial production and the production of daily consumer goods, such as fire-fighting foams, non-stick pans, lubricants, cosmetics, surfactants, food packaging, and electroplating. They are widely present in water bodies, soil, and organisms, and may have certain impacts or even hazards on the development, growth, and health of animals, plants, and humans. The hazards of PFOA are mainly reflected in the following aspects:

[0003] 1. Impact on Aquatic Organisms: Water is the ultimate sink for PFOA. The enrichment of PFOA in water may cause aquatic toxicity to a large number of aquatic organisms, such as acute, chronic, and genotoxic effects on water fleas. Long-term exposure to an environment with PFOA for 21 days can cause significant inhibition of growth and reproduction and lead to death. At high concentrations, it can cause DNA damage. 2. Harm to Terrestrial Plants and Animals: PFOA exposure leads to changes in nutrient composition, which can cause an increase in the level of lipid peroxidation in plant cells, obvious protein aggregation, and DNA structure transformation. Animals exposed to PFOA are also greatly affected by toxic effects, which can affect their fertility and growth and may cause problems such as brain nervous system diseases, endocrine disruption, immunotoxicity, and reproductive toxicity. 3. Threat to Human Health: It affects female and male fertility, pregnancy metabolism, endocrine function (pancreatic dysfunction and the risk of developing type 2 diabetes), lipid metabolism, and the risk of childhood obesity, liver and kidney function, immune function, cardiovascular health, bone health (including the risk of dental caries, osteoporosis, and vitamin D deficiency), nerve function, and the risk of breast cancer. For this reason, perfluorooctanoic acid was listed as a persistent organic pollutant in 2019 and included in Annex A of the Stockholm Convention. In the "Action Plan for the Control of New Pollutants" in 2022, PFOA and its salts and related compounds were included in the list of the first batch of key controlled new pollutants. To address the pollution of persistent pollutants such as PFOA, the Chinese government and all sectors of society should increase the publicity of pollutants, raise public safety awareness, and promote the use of pollution-free products, thereby reducing the harm of persistent pollutants. How to efficiently and environmentally remove PFOA from water remains an urgent problem to be solved. Since PFOA is very stable, traditional water treatment processes cannot effectively remove it. Therefore, there is an urgent need to find efficient and low-cost technologies to eliminate PFOA in the aquatic environment. In recent years, a number of studies have shown that the dual single-atom catalytic technology is a promising treatment technology with good adsorption and degradation effects and can convert persistent organic pollutants into harmless substances under mild conditions. Many scientific researchers have also tried to develop various efficient catalyst materials to adsorb and degrade PFOA in water. This patent attempts to efficiently adsorb and degrade PFOA by regulating the coordination microenvironment of dual single-atom active sites and optimizing the electron co-transfer path of metal centers in the catalyst, and prepares a catalytic material and supporting technology that can rapidly adsorb and degrade PFOA, providing technical support for effectively removing PFOA from water.

[0004] Among the numerous reported catalytic materials, NiFe has attracted much attention due to its unique dual single-atom structure, simple synthesis method, good chemical stability, and excellent adsorption effect. It can have good adsorption and degradation effects both at room temperature and under strong light, and stable chemical bonds are formed between molecules and the surface of the metal catalyst. In the invention, a class of NiFe catalysts that regulate the coordination microenvironment of dual single-atom active sites and optimize the electron co-transfer path of metal centers in the catalyst is prepared, providing a new method for treating water pollution and protecting the environment. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a preparation method of a catalyst that is simple to operate and environmentally friendly for removing PFOA, which can regulate the coordination microenvironment of dual single-atom active sites and optimize the electron co-transfer path of metal centers in the catalyst, and an application research on accelerating the adsorption and catalytic degradation of PFOA.

[0006] The present invention adopts the following technical solution to solve the above technical problem. A method for the efficient adsorption and catalytic degradation of PFOA using a dual single-atom material, the specific steps are as follows:

[0007] (1) Dissolve 2-methylimidazole in methanol to prepare solution A;

[0008] (2) Add solution A to methanol containing Zn(NO 3 ) 2 ·6H 2 O and Fe(NO 3 ) 3 ·9H 2 O to prepare solution B;

[0009] (3) Gradually heat from room temperature to 50 - 80 °C in a water bath under the condition of being covered with a film throughout the process, statically grow for 11 - 14 hours and then stir for 11 - 14 hours to control the constant solution concentration;

[0010] (4) Centrifuge the obtained precipitate, wash it several times with methanol, and dry it overnight in vacuo to obtain the ZIF-8 precursor;

[0011] (5) Disperse the ZIF-8 precursor in n-hexane and ultrasonicate it at room temperature;

[0012] (6) Ni(NO 3 ) 2、 Mn(NO 3 ) 2、 Co(NO 3 ) 2、 Bi(NO 3 ) 3 or Cu(NO 3 )2 The methanol solution was added dropwise to the above-mentioned n-hexane solution and stirred continuously for 2 h;

[0013] (7) Centrifuge and wash several times with methanol, and dry overnight in vacuo;

[0014] (8) Heat the sample to 900 - 1100 °C in an Ar atmosphere and hold for 60 - 90 min to prepare NiFe, MnFe, CoFe, BiFe or CuFe catalysts;

[0015] (9) The NiFe, MnFe, CoFe, BiFe or CuFe catalysts are used for efficient adsorption and catalytic degradation of PFOA.

[0016] Preferably, the specific steps are as follows:

[0017] In step (6), the Ni(NO 3 ) 2、 Mn(NO 3 ) 2 or Co(NO 3 ) 2 The methanol solution was added dropwise to the above-mentioned n-hexane solution and stirred continuously for 2 h;

[0018] In step (8), the sample was heated to 900 - 1100 °C in an Ar atmosphere and held for 60 - 90 min to prepare NiFe, MnFe or CoFe catalysts.

[0019] Preferably, the specific steps are as follows:

[0020] (1) Dissolve 3.94 g of 2-methylimidazole in 150 mL of methanol to prepare solution A;

[0021] (2) Add solution A to 150 mL of methanol containing 3.39 g of Zn(NO 3 ) 2 ·6H 2 O and 80 mg of Fe(NO 3 ) 3 ·9H 2 O to prepare solution B;

[0022] (3) Gradually heat from room temperature to 50 - 80 °C in a water bath under the condition of covering the film throughout the process, statically grow for 11 - 14 hours and then stir for 11 - 14 hours to control the constant solution concentration;

[0023] (4) Centrifuge the obtained precipitate, wash several times with methanol, and dry overnight in vacuo at 60 °C to obtain the ZIF-8 precursor;

[0024] (5) Disperse 150 mg of ZIF-8 precursor into 18 mL of n-hexane and ultrasonicate for 70 minutes at room temperature;

[0025] (6) Gradually add 25 mg mL -1 , 210 μL of Ni(NO 3 ) 2、 Mn(NO 3 ) 2或 Co(NO 3 ) 2 methanol solution dropwise into the above n-hexane solution and continuously stir for 2 h;

[0026] (7) Centrifuge and wash with methanol multiple times, then dry overnight in vacuum at 60 °C;

[0027] (8) Finally, heat the sample to 900 - 1100 °C in an Ar atmosphere and hold for 60 - 90 min to prepare NiFe, MnFe or CoFe catalysts.

[0028] (9) The NiFe, MnFe or CoFe catalysts are used for efficient adsorption and catalytic degradation of PFOA.

[0029] Preferably, the specific steps are as follows: Take 30 mL of the prepared PFOA solution with a concentration of 15 mg / L in a washing bottle at 25 °C. Secondly, add 0.2 g / L of the NiFe, MnFe, CoFe, BiFe or CuFe catalyst material into the above solution and react for 2 hours. During this period, take samples and filter the solution through a water-based system filtration membrane with a pore size of 0.22 μm into a liquid vial. Then, conduct experiments in the liquid phase under the conditions of mobile phase acetonitrile, 5 mM disodium hydrogen phosphate with a pH of 3, a set temperature of 45 °C, and ultraviolet light at a wavelength of 210 nm.

[0030] Preferably, (1) Dissolve 3.94 g of 2-methylimidazole in 150 mL of methanol to prepare solution A;

[0031] (2) Add solution A to 150 mL of methanol containing 3.39 g of Zn(NO 3 ) 2 ·6H 2 O and 80 mg of Fe(NO 3 ) 3 ·9H 2 O to prepare solution B;

[0032] (3) Gradually heat from room temperature to 50 - 80 °C in a water bath under the condition of covering with a film, statically grow for 11 - 14 hours and then stir for 11 - 14 hours to control the constant solution concentration;

[0033] (4) Centrifuge the obtained precipitate, wash it several times with methanol, and dry it overnight in vacuo at 60 °C to obtain the ZIF-8 precursor;

[0034] (5) Disperse 150 mg of the ZIF-8 precursor into 18 mL of n-hexane and sonicate it at room temperature for 70 minutes;

[0035] (6) Add 25 mg mL -1 , 210 μL of Co(NO 3 ) 2 methanol solution dropwise into the above n-hexane solution and continuously stir for 2 h;

[0036] (7) Centrifuge and wash it several times with methanol, and dry it overnight in vacuo at 60 °C;

[0037] (8) Finally, heat the sample to 900 - 1100 °C in an Ar atmosphere and hold for 60 - 90 min to prepare the CoFe catalyst.

[0038] (9) The CoFe catalyst is used for efficient adsorption and catalytic degradation of PFOA: Take 30 mL of the prepared PFOA solution with a concentration of 15 mg / L in a washing bottle at 25 °C. Secondly, add 0.2 g / L of the CoFe catalyst material to the above solution and react for 2 hours. During this period, take samples and filter the solution through a water-based system filter membrane with a pore size of 0.22 μm into a liquid vial. Then, conduct experiments in the liquid phase under ultraviolet light with a mobile phase of acetonitrile, 5 mM disodium hydrogen phosphate with a pH of 3, and a set temperature of 45 °C and a wavelength of 210 nm.

[0039] Beneficial effects:

[0040] A NiFe catalyst capable of effectively removing PFOA is prepared by a simple and feasible preparation method, which has the characteristic of effectively removing PFOA at room temperature; A method for obtaining high-performance adsorption and catalytic degradation materials through a simple and green preparation process is provided. The removal rate of PFOA by the photocatalytic oxidation TiO2-based catalyst in commercial catalysts is 70 - 90% (reacting for several hours); For heterogeneous catalytic iron-carbon composites or supported catalysts, a degradation rate of more than 80% can be achieved under optimized conditions (acidic pH, high temperature), but the reaction time is long (several hours to dozens of hours); For electrochemical catalysis (such as boron-doped diamond electrodes), the current density and electrode material directly affect the efficiency. Some commercial systems report a removal rate > 90%, but energy consumption and electrode loss are challenges; For persulfate (such as Fe 3+ / UV) generates strong oxidizing sulfate radicals (SO 4 -·), the PFOA removal rate can reach 60 - 85%, but the pH and interference of coexisting ions need to be controlled. With its simple and green preparation process and short - time removal effect, the present invention is expected to become one of the mainstream solutions for PFOA treatment.

[0041] The present invention relates to a preparation method of a material for efficiently adsorbing and catalytically degrading PFOA by regulating the coordination micro - environment of dual single - atom active sites and optimizing the electron co - transfer path of metal centers in the catalyst. The present invention belongs to the field of catalytic technology. The specific steps are as follows: Prepare the ZIF - 8 precursor. Dissolve 3.94 g of 2 - methylimidazole (MeIM) in 150 mL of methanol to prepare solution A, and add it to 150 mL of methanol containing 3.39 g of Zn(NO 3 ) 2 ·6H 2 O and 80 mg of Fe(NO 3 ) 3 ·9H 2 O to prepare solution B. Gradually heat from room temperature to 50 - 80 °C in a water - bath under full - film condition, statically grow for 11 - 14 hours and then stir for 11 - 14 hours to control the constant solution concentration. Centrifuge the obtained precipitate, wash it several times with methanol, and dry it in a vacuum at 60 °C for 12 h. Finally, disperse 150 mg of the ZIF - 8 precursor into 18 mL of n - hexane and ultrasonicate it at room temperature for 70 minutes. Dropwise add the methanol solution of Ni(NO 3 ) 2 (25 mg mL -1 , 210 μL) into the above - mentioned n - hexane solution and continuously stir for 2 h, centrifuge and wash it with methanol for multiple times, dry it overnight in a vacuum at 60 °C, and then heat the sample to 900 - 1100 °C in an Ar atmosphere and hold it for 60 - 90 min to prepare the NiFe catalyst. The catalytic material prepared by the preparation method provided by the present invention has excellent adsorption and catalytic degradation performance, can rapidly adsorb PFOA pollutants in normal - temperature sewage, and other dual single - atom catalysts synthesized by the same method also have excellent adsorption and catalytic degradation performance. For the NiFe catalyst, it can adsorb and degrade more than 80% within 10 minutes and reach nearly 100% within 2 hours, providing good removal materials and technical support for the application of catalytic reactions in wastewater treatment.

[0042] First, a temperature - controlled experiment on the adsorption and degradation of PFOA was carried out using a constant - temperature water - bath, and the results are as Figure 4As shown in (a), in the adsorption and degradation experiments of PFOA by the catalyst at different temperatures, at 15°C, the removal rate of PFOA reached 81.9% in 20 minutes and nearly 100% in 2 hours; at 45°C, the removal rate of PFOA reached 11.5% and the maximum of 13.2% was only achieved in 2 hours; at 25°C, the removal rate of PFOA reached 92.5% in 20 minutes and nearly 100% in 2 hours, with the best effect.

[0043] Combined with Figure 4 the removal effect of the MnFe catalyst reached 93.1% in 10 minutes and nearly 100% in 2 hours.

[0044] Combined with Figure 4 the removal effect of the CoFe catalyst reached 89.3% in 10 minutes and nearly 100% in 2 hours. Description of the Drawings

[0045] Figure 1 is the XRD pattern of the catalyst prepared in Example 1 of the present invention;

[0046] Figure 2 is the SEM pattern of the catalyst prepared in Example 1 of the present invention: (a) is Fe, (b) is Ni, and (c) is NiFe;

[0047] Figure 3 is the infrared spectrum of all the catalysts prepared in Examples 1, 3, and 4 of the present invention;

[0048] Figure 4 is the liquid phase diagram of the adsorption and catalytic degradation of PFOA by the catalysts prepared in Examples 2, 3, and 4: the adsorption and degradation effect diagrams at different temperatures (a), the adsorption and degradation effect diagrams of pure iron, pure nickel, and nickel-iron bonded catalysts (b), the adsorption and degradation effect diagrams of different catalysts (c), and the adsorption and degradation effect diagrams after single-atom quenching of different catalysts (d). Detailed Embodiments

[0049] The above content of the present invention will be further described in detail below through examples, but it should not be understood that the scope of the above subject matter of the present invention is limited to the following examples. All technologies implemented based on the above content of the present invention belong to the scope of the present invention.

[0050] Example 1:

[0051] 1) Dissolve 3.94 g of 2-methylimidazole (MeIM) in 150 mL of methanol to prepare solution A.

[0052] 2) Add solution A to a solution containing 3.39 g of Zn(NO 3 )2 ·6H 2 O and 80 mg of Fe(NO 3 ) 3 ·9H 2 O were dissolved in 150 mL of methanol to prepare Solution B.

[0053] 3) Under the condition of covering the film throughout the process in a water bath, the temperature was gradually increased from room temperature to 60 °C, and static growth was carried out for 12 hours and then stirred for 12 hours to control the constancy of the solution concentration. Without the film covering condition throughout the process, the solution concentration would increase, resulting in inconsistent concentrations in subsequent experiments. Therefore, the film covering condition was retained.

[0054] 4) The obtained precipitate was centrifuged, washed several times with methanol, and dried overnight in vacuo at 60 °C to obtain ZIF-8.

[0055] 5) 150 mg of ZIF-8 was dispersed in 18 mL of n-hexane and sonicated at room temperature for 70 minutes.

[0056] 6) The methanol solution of Ni(NO 3 ) 2 (25 mg mL -1 , 210 μL) was added dropwise to the above n-hexane solution and continuously stirred for 2 h.

[0057] 7) Centrifuge and wash several times with methanol, and dry overnight in vacuo at 60 °C.

[0058] 8) Finally, the sample was heated to 1000 °C in an Ar atmosphere and held for 60 min to prepare the NiFe catalyst.

[0059] The catalyst prepared in Example 1 was subjected to phase analysis by XRD and morphological characterization by SEM. As Figure 1 shown, the XRD characterization results confirmed that the material was Fe, Ni, and NiFe. It can be seen that the peak intensities of the (002) and (101) crystal planes of NiFe were similar to those of other catalysts. From Figure 2 the SEM characterization results, it can be seen that the morphology of the Fe catalyst was in block shape, the morphology of the Ni catalyst was in granular shape, and the NiFe catalyst was in wire-block shape. Figure 3 is the Fourier transform infrared spectroscopy (FT-IR) spectrum. The absorption peaks at 1625 cm −1 and 3433 cm −1 corresponded to the adsorbed water molecules and the stretching vibration mode of surface bonding, respectively. There were strong peaks at both positions for NiFe, indicating the highest content of bonding. This also confirmed that we successfully prepared a dual single-atom catalytic material with excellent adsorption-catalysis synergistic effect by regulating the coordination microenvironment of the dual single-atom active sites, that is, optimizing the electron co-transfer path of different metal centers in the catalyst.

[0060] Example 2

[0061] Basically the same as Example 1, except that: in step 6, the Ni(NO 3 ) 2 methanol solution is replaced with a Mn(NO 3 ) 2 methanol solution or a Co(NO 3 ) 2 methanol solution, etc., to obtain different dual single-atom bonded catalyst materials, which are respectively labeled as MnFe, CoFe, etc.

[0062] First, a temperature control experiment on the adsorption and degradation of PFOA was carried out using a constant temperature water bath. The results are as Figure 4 (a) shown. In the adsorption and degradation experiments of the catalyst on PFOA at different temperatures, at 15 °C, the removal rate of PFOA reached 81.9% in 20 minutes and nearly 100% in 2 hours; at 45 °C, the removal rate of PFOA reached 11.5% and only reached the maximum of 13.2% in 2 hours; at 25 °C, the removal rate of PFOA reached 92.5% in 20 minutes and nearly 100% in 2 hours, with the best effect.

[0063] Subsequent experiments were carried out at this temperature. Therefore, 30 mL of the prepared PFOA solution with a concentration of 15 mg / L was taken in a washing bottle at 25 °C, and then 0.2 g / L of the NiFe catalyst material was added to the above solution. The reaction was carried out for 2 hours. During this period, samples were taken and the solution was filtered through a water-based system filter membrane with a pore size of 0.22 μm into a liquid phase vial. Then, experiments were carried out in the liquid phase under ultraviolet light with a mobile phase of acetonitrile, 5 mM disodium hydrogen phosphate with a pH of 3, and a set temperature of 45 °C and a wavelength of 210 nm.

[0064] To exclude the influence of single atoms in the material, adsorption and degradation experiments of Fe, Ni, and NiFe were respectively carried out. The results are as Figure 4 (b) the liquid phase results shown, excluding the influence of the materials Fe and Ni. Basically the same as Example 1, for the synthesis of Fe and Ni, first, 3.94 g of 2-methylimidazole (MeIM) was dissolved in 150 mL of methanol to prepare solution A. Solution A was added to a solution containing 3.39 g of Zn(NO 3 ) 2 ·6H 2 O and 80 mg of Fe(NO 3 ) 3 ·9H 2 O or 80 mg of Ni(NO 3 ) 2 ·6H 2In 150 mL of methanol of O, solution B was prepared. The solution was gradually heated from room temperature to 60 °C in a water bath under full film coverage, statically grown for 12 hours and then stirred for 12 hours to control the constant solution concentration. The obtained precipitate was centrifuged, washed several times with methanol, and dried overnight in vacuo at 60 °C to obtain ZIF-8. Finally, the sample was heated to 1000 °C in an Ar atmosphere and held for 60 min to prepare Fe and Ni catalysts.

[0065] According to Figure 4 (c), the metal-bonded materials of MnFe, CoFe and NiFe have similar adsorption and catalytic degradation effects, indicating that this type of catalyst has universality.

[0066] To further study the influence of single-atom catalysts in the catalyst, combined with Figure 4 (c) and Figure 4 the results of single-atom quenching in (d), it can be seen that the removal effect becomes significantly worse after single-atom quenching, indicating that single-atom active sites play a major role.

[0067] Example 3:

[0068] Preparation of MnFe catalyst:

[0069] First, 30 mL of the prepared PFOA solution with a concentration of 15 mg / L was taken in a washing bottle at 25 °C. Secondly, 0.2 g / L of the MnFe catalyst material was added to the above solution, and the reaction was carried out for 2 hours. During this period, samples were taken and the solution was filtered through a water-based system filter membrane with a pore size of 0.22 μm into a liquid vial. Then, experiments were carried out in the liquid phase with mobile phase acetonitrile, 5 mM disodium hydrogen phosphate with a pH of 3, and a set temperature of 45 °C and a wavelength of 210 nm under ultraviolet light. Combining Figure 4 with the removal effect of the MnFe catalyst in (c), it reached 93.1% in 10 min and nearly 100% in 2 hours.

[0070] Example 4:

[0071] Preparation of CoFe catalyst:

[0072] First, 30 mL of the prepared PFOA solution with a concentration of 15 mg / L was taken in a washing bottle at 25 °C. Secondly, 0.2 g / L of the CoFe catalyst material was added to the above solution, and the reaction was carried out for 2 hours. During this period, samples were taken and the solution was filtered through a water-based system filter membrane with a pore size of 0.22 μm into a liquid vial. Then, experiments were carried out in the liquid phase with mobile phase acetonitrile, 5 mM disodium hydrogen phosphate with a pH of 3, and a set temperature of 45 °C and a wavelength of 210 nm under ultraviolet light. Combining Figure 4 with the removal effect of the CoFe catalyst in (c), it reached 89.3% in 10 min and nearly 100% in 2 hours.

[0073] The present invention is not limited to the specific technical solutions described in the above embodiments, and all technical solutions formed by equivalent substitution are within the scope of protection required by the present invention.

Claims

1. A method for using double single-atom materials for efficient adsorption and catalytic degradation of PFOA, characterized in that: The specific steps are: (1) Dissolve 2-methylimidazole in methanol to prepare solution A; (2) Add solution A to methanol containing Zn(NO3)2·6H2O and Fe(NO3)3·9H2O to prepare solution B; (3) Gradually raise the temperature from room temperature to 50-80°C in a water bath under full coating conditions, grow statically for 11-14 hours, and then stir for another 11-14 hours to control the solution concentration to be constant; (4) centrifuging the obtained precipitate, washing it with methanol several times, and drying it in a vacuum overnight to obtain a ZIF-8 precursor; (5) dispersing the ZIF-8 precursor in n-hexane and ultrasonicating at room temperature; (6) Ni(NO3) 2、 Mn(NO3) 2、 Co(NO3) 2、 Bi(NO3)3 or Cu(NO3)2 methanol solution was added dropwise into the above n-hexane solution with continuous stirring; (7) centrifugation and washing with methanol several times, and drying in vacuum overnight; (8) heating the sample to 900-1100°C in an Ar atmosphere for 60-90 min to prepare NiFe, MnFe, CoFe, BiFe or CuFe catalysts; (9) NiFe, MnFe, CoFe, BiFe or CuFe catalysts are used for efficient adsorption and catalytic degradation of PFOA.

2. The method for using the double monoatom material according to claim 1 to efficiently adsorb and catalytically degrade PFOA, characterized in that: The specific steps are: In the step (6), Ni(NO3) 2、 Mn(NO3)2 or Co(NO3)2 methanol solution was added dropwise into the above n-hexane solution and stirred for 2 h; In the step (8), the sample is heated to 900-1100° C. in an Ar atmosphere and maintained for 60-90 min to prepare a NiFe, MnFe or CoFe catalyst.

3. The method for using the double monoatom material according to claim 1 to efficiently adsorb and catalytically degrade PFOA, characterized in that: The specific steps are: (1) Dissolve 3.94 g of 2-methylimidazole in 150 mL of methanol to prepare solution A; (2) Solution A was added to 150 mL of methanol containing 3.39 g Zn(NO3)2·6H2O and 80 mg Fe(NO3)3·9H2O to prepare solution B; (3) gradually raising the temperature from room temperature to 50-80°C in a water bath under full coating conditions, statically growing for 11-14 hours and then stirring for another 11-14 hours to control the solution concentration to be constant; (4) The resulting precipitate was centrifuged, washed several times with methanol, and dried in a vacuum at 60°C overnight to obtain a ZIF-8 precursor; (5) Disperse 150 mg of ZIF-8 precursor in 18 mL of n-hexane and ultrasonicate at room temperature for 70 min; (6) 25 mg mL -1 , 210 μL Ni(NO3) 2、 Mn(NO3)2 or Co(NO3)2 methanol solution was added dropwise to the above n-hexane solution and stirred for 2 h; (7) centrifugation and washing with methanol several times, and drying in a vacuum at 60°C overnight; (8) The sample was heated to 900~1100℃ in an Ar atmosphere and maintained for 60~90min to prepare NiFe, MnFe or CoFe catalysts.

4. (9) NiFe, MnFe or CoFe catalysts are used for efficient adsorption and catalytic degradation of PFOA.

5. The method for using the double monoatom material for efficient adsorption and catalytic degradation of PFOA according to claim 1, characterized in that: The specific steps are as follows: at 25°C, take 30 mL of a prepared 15 mg / L PFOA solution in a rinse bottle, then add 0.2 g / L of NiFe, MnFe, CoFe, BiFe or CuFe catalyst material to the above solution, react for 2 hours, during which time take a point to filter the solution with a water system filter membrane with a pore size of 0.22 μm into a liquid phase vial, and then conduct the experiment in the liquid phase with acetonitrile and 5 mM sodium dihydrogen phosphate at a pH of 3 as the mobile phase and a set temperature of 45°C and a wavelength of 210 nm under ultraviolet light.

6. The method for using the double monoatom material for efficient adsorption and catalytic degradation of PFOA according to claim 1, characterized in that: (1) Dissolve 3.94 g of 2-methylimidazole in 150 mL of methanol to prepare solution A; (2) Solution A was added to 150 mL of methanol containing 3.39 g Zn(NO3)2·6H2O and 80 mg Fe(NO3)3·9H2O to prepare solution B; (3) gradually raising the temperature from room temperature to 50-80°C in a water bath under full coating conditions, statically growing for 11-14 hours and then stirring for another 11-14 hours to control the solution concentration to be constant; (4) The resulting precipitate was centrifuged, washed several times with methanol, and dried in a vacuum at 60°C overnight to obtain a ZIF-8 precursor; (5) Disperse 150 mg of ZIF-8 precursor in 18 mL of n-hexane and ultrasonicate at room temperature for 70 min; (6) 25 mg mL -1 , 210 μL Co(NO3)2 methanol solution was added dropwise to the above n-hexane solution and stirred for 2 h; (7) centrifugation and washing with methanol several times, and drying in a vacuum at 60°C overnight; (8) The sample was heated to 900~1100℃ in an Ar atmosphere and maintained for 60~90min to prepare a CoFe catalyst.

7. (9) CoFe catalyst for efficient adsorption and catalytic degradation of PFOA: at 25°C, take 30 mL of a prepared 15 mg / L PFOA solution in a rinse bottle, then add 0.2 g / L of CoFe catalyst material to the above solution and react for 2 hours. During this period, filter the solution with a water system filter membrane with a pore size of 0.22 μm into a liquid phase vial. Then, the experiment was carried out in the liquid phase with acetonitrile and 5 mM sodium dihydrogen phosphate at pH 3 as the mobile phase and the set temperature was 45°C and the wavelength of ultraviolet light was 210 nm.

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