A heterogeneous fenton catalyst synthesis and its application for degradation of pfas

Abstract

The present application relates to a kind of heterogeneous fenton catalyst synthesis and its application for degrading PFAS, belong to environmental engineering water treatment technical field.Calcine MOF material under non-oxidizing atmosphere, obtain carbonized MOF material, and as template, with FeSO4, Na2S2O3 And sulfur element as raw material, FeS2 is synthesized by hydrothermal method, and heterogeneous fenton catalyst is prepared.Then, three-electrode system is constructed, and FeS2-MOF is used as catalyst for efficient degradation of PFAS @C, the heterogeneous fenton catalyst has crystal structure stable, electron transfer efficiency is high and catalytic performance is superior and the like advantage, suitable for removing various refractory organic pollutants.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of environmental engineering water treatment, and more particularly relates to a heterogeneous Fenton catalyst synthesis and its application for degrading PFAS. BACKGROUND

[0002] Perfluorooctanoic acid (PFOA) as a common polyfluoro- and / or perfluoro-compound (PFAS) poses a serious threat to the environment and biological health due to its chemical stability and non-biodegradability. Traditional water treatment methods such as activated carbon adsorption, chemical oxidation and biodegradation have limited effect on removing PFOA, which is difficult to meet the actual demand. Therefore, it is of great significance to develop new and efficient removal technology. Electro-Fenton technology generates H2O2 by electrolysis of water, which generates hydroxyl radicals (·OH) with strong oxidizing ability under the action of catalyst, thereby efficiently degrading organic pollutants. Compared with traditional Fenton reaction, electro-Fenton method can be carried out under relatively mild conditions, and can continuously generate H2O2, with high degradation efficiency and environmental friendliness. However, the key to electro-Fenton method is the selection and design of catalyst, and the ideal catalyst should have high H2O2 decomposition capacity, stable crystal structure and excellent electron transfer performance. Metal-organic framework materials (MOFs) have become ideal electro-Fenton catalyst materials due to their excellent structure and catalytic performance, but there are problems such as stability and electron transfer efficiency in their single application.

[0003] In recent studies, Wang et al. prepared Fe / S doped aerogel Fenton catalyst and applied it to the degradation of PFOA, and the PFOA degradation rate was only 21.6% within 3 hours [Sci. Total Environ., 2020, 714: 136436], and the preparation process is complex, time-consuming, low yield and high energy consumption. SUMMARY

[0004] The present application provides a heterogeneous Fenton catalyst and a method for efficiently removing PFAS by in-situ generation of H2O2 through electro-Fenton method, using carbonized MOF material as template, FeSO 4、 Na2S2O3 and elemental sulfur as raw materials, FeS2 is synthesized by hydrothermal method to prepare heterogeneous Fenton catalyst. The heterogeneous Fenton catalyst prepared by the present application has the characteristics of stable crystal structure, high electron transfer efficiency, excellent catalytic performance, wide reaction environment adaptability, etc. Through the synergistic effect of efficient and stable catalyst and electrochemical reaction, the effect of efficiently removing PFAS is achieved. Thus, the technical problem of low degradation efficiency of polyfluoro- and / or perfluoro-compounds in the prior art is solved.

[0005] According to the first aspect of the present application, a synthesis method of a heterogeneous Fenton catalyst is provided, comprising the following steps:

[0006] (1) calcining the MOF material under a non-oxidizing atmosphere to obtain a carbonized MOF material;

[0007] (2) using the carbonized MOF material obtained in step (1) as a template, using FeSO 4、 Na2S2O3 and elemental sulfur as raw materials, FeS2 is synthesized by a hydrothermal method, thereby obtaining a heterogeneous Fenton catalyst with the carbonized MOF material as a template.

[0008] Preferably, in step (1), the MOF material is prepared by a microwave method.

[0009] Preferably, the synthesis conditions of the microwave method are time of 20-40 minutes, power of 50-150 W per jar, and temperature of 100-140℃.

[0010] Preferably, in step (1), the MOF material is a MOF-74 material, which is synthesized from raw materials FeSO4·7H2O and 2,5-dihydroxyterephthalic acid.

[0011] Preferably, in step (1), the calcination temperature is 400-600℃, the heating rate is 4-6℃ / min, and the holding time is 1-3 hours.

[0012] According to another aspect of the present application, there is provided a heterogeneous Fenton catalyst prepared by any one of the methods.

[0013] According to another aspect of the present application, there is provided a use of the heterogeneous Fenton catalyst for degrading polyfluorinated and / or perfluorinated compounds.

[0014] Preferably, the use is a three-electrode system electro-Fenton method for degrading and removing polyfluorinated and / or perfluorinated compound organic pollutants.

[0015] Preferably, the use specifically refers to: using copper-deposited graphite felt as a working electrode, using a boron-doped diamond electrode as a counter electrode, using an Ag / AgCl electrode as a reference electrode, using Na2SO4 as an electrolyte, dispersing the heterogeneous Fenton catalyst and the pollutants in the electrolyte; the working electrode is used to reduce O2 in an aqueous solution to produce H2O2, and the heterogeneous Fenton catalyst is used to accelerate the decomposition of H2O2, thereby catalyzing the generation of more active oxygen species and achieving efficient degradation of the pollutants.

[0016] Preferably, the mass-to-volume ratio of the heterogeneous Fenton catalyst to the electrolyte divided by the concentration of the organic pollutants is 30-60; the voltage applied in the electro-Fenton method is -0.5 to -1.0 V, the reaction time is less than 3 hours, and the aeration rate is 2.5 L / min.

[0017] Overall, compared with the prior art, the above technical solutions conceived by the present application can at least achieve the following beneficial effects:

[0018] (1) The heterogeneous Fenton catalyst of the present application has the characteristics of stable crystal structure, high electron transfer efficiency, superior catalytic performance, and wide reaction environment adaptability, and has broad application prospects in environmental pollution control. The research of the present application not only provides a new idea for the development of electro-Fenton technology, but also provides an effective solution for the treatment of refractory organic pollutants in practical applications.

[0019] (2) The present application proposes a preparation method of a composite catalyst (FeS2-MOF@C) based on MOF (preferably MOF-74(Fe)) and its application in electro-Fenton method. The heterogeneous Fenton catalyst has the characteristics of stable crystal structure, high electron transfer efficiency, superior catalytic performance, and wide reaction environment adaptability, and has broad application prospects in environmental pollution control. The research of the present application not only provides a new idea for the development of electro-Fenton technology, but also provides an effective solution for the treatment of refractory organic pollutants in practical applications.

[0020] (3) Preferably, the FeS2-MOF@C composite catalyst prepared by microwave-assisted synthesis, nitrogen atmosphere calcination and hydrothermal method is combined with a three-electrode system constructed by a copper-deposited graphite felt electrode (GF / Cu), a boron-doped diamond electrode (BDD electrode) and an Ag / AgCl reference electrode. The BDD electrode is used to capture the electrons of the PFAS carboxyl group, and then the unstable carboxyl group is converted into CO2, which is beneficial to the further defluorination of PFAS; the GF / Cu is used to efficiently reduce O2 in the aqueous solution to produce H2O2, and the heterogeneous Fenton catalyst is used to accelerate the decomposition of H2O2 to generate a large number of active oxygen species, thereby realizing efficient degradation of PFAS.

[0021] (4) Preferably, the MOF-74(Fe) is synthesized by a microwave-assisted synthesis method. Compared with the traditional thermodynamic synthesis method, microwave radiation can significantly improve the rate and efficiency of chemical reactions. Under microwave heating, MOF-74(Fe) is synthesized efficiently and in high yield, and its crystal structure, stability and surface morphology are optimized, laying a solid foundation for the performance improvement of the subsequent catalyst.

[0022] (5) The present application uses MOF-74 as a carrier and successfully synthesizes FeS2 through a hydrothermal method to form a FeS2-MOF@C heterogeneous Fenton catalyst. The high surface area and pore structure of the MOF provide good carrier support, which is conducive to the uniform dispersion and immobilization of FeS2, thereby enhancing the stability and catalytic activity of the catalyst. This composite strategy not only effectively increases the specific surface area and reaction activity of the catalyst, but also slows down the deactivation rate of FeS2 in the electro-Fenton reaction, prolonging the service life of the catalyst.

[0023] (6) The FeS2-MOF@C heterogeneous Fenton catalyst proposed in the present application exhibits excellent stability during the reaction process. Compared to the method of sulfidizing MOF@C in a tube furnace, the template method selected by the present application helps to form a FeS2-MOF@C catalyst with a more stable crystal structure. In addition, high-temperature sulfidization treatment in a tube furnace can also cause non-uniformity and deactivation of the crystal structure of the catalyst, limiting its practical application in complex environments.

[0024] (7) The FeS2-MOF@C heterogeneous Fenton catalyst proposed in the present application exhibits excellent catalytic activity and stability in the electro-Fenton method, and can efficiently generate various active oxygen species, thereby significantly improving the degradation efficiency of PFOA and other refractory organic pollutants. Compared with traditional chemical oxidation methods, it is more efficient and does not produce secondary pollutants, and is suitable for practical application under complex water quality conditions.

[0025] (8) The electro-Fenton system designed in the present application can not only be used for PFOA removal, but also has the potential to treat other refractory organic pollutants. The heterogeneous Fenton catalyst of the present application has a removal rate of 100% for 10 mg / L PFOA in 3 hours, a defluorination rate of 76%, and can still maintain a removal rate of 94% and a defluorination rate of 71% after three cycles. By adjusting the ratio of the catalyst and the reaction conditions, efficient degradation of various organic pollutants can be achieved, suitable for wastewater treatment of different types and concentrations.

[0026] (9) The electro-Fenton method used in the present application is itself a low-energy and low-pollution environmental governance technology, and the present application further optimizes the design of the catalyst, reducing the dependence on external chemicals and the risk of secondary pollution, in line with the environmental protection requirements of sustainable development. Through this technology, water quality can be effectively improved, and the ecological environment and human health can be protected. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Scanning electron micrographs of different types of catalysts.

[0028] Figure 2 XRD pattern of the FeS2-MOF@C catalyst prepared in Example 1.

[0029] Figure 3 The effect diagram of different kinds of catalysts for removing PFOA by electro-Fenton.

[0030] Figure 4 The effect diagram of FeS2-MOF@C catalyst for removing PFOA by electro-Fenton under different dosages.

[0031] Figure 5 The effect diagram of FeS2-MOF@C catalyst for removing PFOA by electro-Fenton under different voltages.

[0032] Figure 6 The effect and defluorination rate diagram of FeS2-MOF@C catalyst for removing PFOA by electro-Fenton under different cycle numbers.

[0033] Figure 7 The effect diagram of FeS2-MOF@C catalyst for removing PFOA by electro-Fenton under different counter electrodes. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0035] The present application provides a heterogeneous Fenton catalyst and a preparation method thereof, and is applied to the electro-Fenton method for efficiently removing PFAS. Preferably, the specific steps include: using a microwave digestion instrument to synthesize MOF-74(Fe) with excellent crystal structure by a microwave-assisted method; calcining the synthesized MOF-74 in a tube furnace under a nitrogen atmosphere to obtain MOF@C; synthesizing FeS2 by a hydrothermal method with MOF@C as a template to prepare a FeS2-MOF@C heterogeneous Fenton catalyst; constructing a three-electrode system with GF / Cu as a working electrode, BDD as a counter electrode, and Ag / AgCl as a reference electrode, and using FeS2-MOF@C as a catalyst to efficiently degrade PFAS by the electro-Fenton method.

[0036] Preferably, the concentration ratio of the raw materials FeSO4·7H2O and 2,5-dihydroxyterephthalic acid for synthesizing MOF-74 is 4:1-1:4.

[0037] Further preferably, the molar ratio of the raw materials FeSO4·7H2O and 2,5-dihydroxyterephthalic acid for synthesizing MOF-74 is 1:2 (1.25 mmol:2.5 mmol), and the corresponding masses are 0.2477 g and 0.4971 g, respectively.

[0038] Further preferably, the solvent for synthesizing MOF-74 is N,N-dimethylformamide, anhydrous ethanol and water, in a ratio of 15:1:1; the total volume of the mixed solvent in the synthesis process is 20 mL, and 0.3 g of polyvinylpyrrolidone (PVP) is dissolved in the mixed solution.

[0039] Preferably, the microwave-assisted synthesis of MOF-74 is performed using a microwave digestion instrument, and the synthesis conditions are a time of 20-40 minutes, a power of 50-150 W per jar, and a temperature of 100-140℃.

[0040] Preferably, the washing method for synthesizing MOF-74 is to wash with anhydrous ethanol and water for three times, respectively.

[0041] Preferably, in the process of using a tube furnace to calcine MOF-74 to generate MOF@C, the conditions of the tube furnace are set as follows: a calcination temperature of 400-600℃, a heating rate of 4-6℃ / min, and a holding time of 1-3 hours.

[0042] Preferably, when synthesizing FeS2-MOF@C, the concentration of FeSO4·7H2O is in the range of 1-2 mol / L, the concentration of Na2S2O3 is in the range of 1-2 mol / L, the concentration of high-purity sulfur is in the range of 0.5-1 mol / L, and the mass-volume ratio of MOF@C to solvent is 3-20 mg / mL.

[0043] Further preferably, when synthesizing FeS2-MOF@C, 0.05 mol of FeSO4·7H2O, 0.05 mol of Na2S2O3, and 0.025 mol of high-purity sulfur are dissolved in 30 mL of ethylene glycol, and finally 0.4 g of MOF@C is poured into the stirring solution, which is placed in a high-pressure reaction kettle for reaction at 180℃ for 24 hours.

[0044] Preferably, when synthesizing FeS2-MOF@C, the washing method is to repeatedly centrifugal clean with dilute sulfuric acid, anhydrous ethanol, and carbon disulfide, respectively.

[0045] Preferably, the conditions for preparing the GF / Cu electrode are an area of 3×3.5 cm, a deposition solution of 200 mL of a mixed solution of CuSO4·5H2O and H2SO4 with a concentration of 50 mM and 0.5 M, a deposition voltage of -0.6 V, and a deposition time of 60 s.

[0046] Preferably, the counter electrode is a BDD electrode with a size of 2×2 cm, and the reference electrode is an Ag / AgCl electrode.

[0047] Preferably, the mass-volume ratio of the heterogeneous Fenton catalyst to the electrolyte divided by the concentration of the organic pollutants is 30-60.

[0048] Further preferably, in the method for efficiently degrading PFAS by electro-Fenton, the amount of catalyst used in the reaction process is 0.4 g / L, the applied voltage is -0.8 V, the reaction time is 3 hours, the aeration rate is 2.5 L / min, the PFOA concentration is 10 mg / L, and the electrolyte volume is 100 mL.

[0049] The following are specific embodiments

[0050] Example 1 Preparation of FeS2-MOF@C catalyst

[0051] (1) Synthesis of MOF: MOF-74(Fe) was synthesized by a microwave-assisted method using a microwave digestion instrument. Specifically, FeSO4·7H2O and 2,5-dihydroxyterephthalic acid were taken in a molar ratio of 1:2 (1.25 mmol:2.5 mmol), corresponding to masses of 0.2477 g and 0.4971 g, respectively, and dissolved in a mixed solvent of N,N-dimethylformamide, ethanol, and water (ratio of 15:1:1, total volume of 20 mL), with the addition of 0.3 g of PVP. The solution was placed in a microwave digestion instrument, with synthesis conditions of 30 minutes, power of 100 W / can, and temperature of 120°C. The product was washed three times each with anhydrous ethanol and pure water.

[0052] (2) Synthesis of MOF@C: The synthesized MOF-74 was calcined in a tube furnace under a nitrogen atmosphere, with a calcination temperature of 500°C, a heating rate of 5°C / min, and a holding time of 2 hours, to obtain carbonized MOF (MOF@C).

[0053] (3) Synthesis of FeS2-MOF@C: 0.05 mol of FeSO4·7H2O, 0.05 mol of Na2S2O3, and 0.025 mol of high-purity sulfur were weighed out, added to 30 mL of ethylene glycol, and then 0.4 g of MOF@C was added and stirred to mix uniformly. The mixture was placed in a high-pressure reaction kettle and reacted at 180°C for 24 h, and then repeatedly centrifuged and washed with dilute sulfuric acid, anhydrous ethanol, and carbon disulfide until the washing liquid became clear.

[0054] Preparation of MOF in Comparative Example 1

[0055] The preparation steps of the MOF in Comparative Example 1 were the same as steps (1) in Example 1.

[0056] Preparation of MOF@C in Comparative Example 2

[0057] The preparation steps of the MOF@C in Comparative Example 2 were the same as steps (1) and (2) in Example 1.

[0058] The FeS2-MOF@C prepared in Example 1, the MOF prepared in Comparative Example 1 and the MOF@C prepared in Comparative Example 2 were characterized, and the results are as follows:

[0059] Figure 1 The scanning electron microscope images of the FeS2-MOF@C prepared in Example 1, the MOF prepared in Comparative Example 1 and the MOF@C prepared in Comparative Example 2 are shown in the figure. The MOF prepared by the microwave method has complete crystal form and consistent structure, which confirms the advantage of the microwave synthesis method. It can be seen from the MOF@C that more pore structures are exhibited after calcination, corresponding to a larger specific surface area. FeS2-MOF@C can clearly see that FeS2 is attached to the surface of MOF@C, which confirms the successful synthesis of FeS2-MOF@C.

[0060] Figure 2 The XRD spectra of the FeS2-MOF@C prepared in Example 1, the MOF prepared in Comparative Example 1 and the MOF@C prepared in Comparative Example 2 are shown in the figure. In the FeS2-MOF@C prepared, the diffraction peak height of FeS2 in the XRD standard card is consistent with that of FeS2 (JCPDS 42-1340). In the spectrum of FeS2, 2θ = 28.58°, 33.15°, 37.12°, 40.8°, 47.57°, 56.4°, 59.18°, 61.8°, 64.18°, respectively, corresponding to (111), (200), (210), (211), (220), (311), (222), (023) and (321) crystal faces, and the XRD spectrum of FeS2-MOF@C corresponds to the superimposed spectrum of FeS2 and MOF@C, which confirms the successful synthesis of FeS2-MOF@C.

[0061] Example 2 FeS2-MOF@C catalyst electro-Fenton removal of PFOA experiment

[0062] A three-electrode system was constructed, and the specific operation was as follows: the graphite felt (GF / Cu) deposited with copper by electrodeposition was used as the working electrode (the area was 3×3.5 cm), the deposition solution was 200 mL of a mixed solution of CuSO4·5H2O and H2SO4 with a concentration of 50 mM and 0.5 M, the deposition voltage was -0.6 V, and the deposition time was 60 s; the counter electrode was a BDD electrode with a size of 2×2 cm; the reference electrode was an Ag / AgCl electrode. The reaction conditions of the electro-Fenton reaction process were as follows: the amount of catalyst was 0.4 g / L, the applied voltage was -0.8 V, the reaction time was 3 hours, the aeration rate was 2.5 L / min, the volume of electrolyte solution was 100 mL, the electrolyte was 0.1 M Na2SO4, the non-homogeneous Fenton catalyst and PFOA were added to the electrolyte to make the concentration of PFOA 10 mg / L, and ultrasonic was used for dispersion.

[0063] Example 3

[0064] The test operation steps of the above embodiment 2 and embodiment 4 are the same as those of embodiment 2, except that the catalyst dosage is 0.1, 0.2, 0.3, and 0.5 g / L.

[0065] The PFOA removal effect of different catalysts in the above embodiment 2 and embodiment 3 is shown in Figure 3 The results show that FeS2-MOF@C prepared by compounding FeS2 and MOF@C has the best PFOA removal effect under the same mass, which confirms that the compounding of the two catalysts can improve the catalytic effect and the necessity of compounding.

[0066] Embodiment 4

[0067] The test operation steps of the above embodiment 2 and embodiment 4 are the same as those of embodiment 2, except that the catalyst dosage is 0.1, 0.2, 0.3, and 0.5 g / L.

[0068] The PFOA removal effect of different catalysts in the above embodiment 2 and embodiment 3 is shown in Figure 4 The results show that the catalyst dosage of 0.4 g / L and 0.5 g / L has the best PFOA removal effect, and the removal rates of the two are not much different. In order to have higher economic benefits, the catalyst dosage of 0.4 g / L is finally selected.

[0069] Embodiment 5

[0070] The test operation steps of the above embodiment 2 and embodiment 5 are the same as those of embodiment 2, except that the applied voltage is -0.5 V, -0.6 V, -0.7 V, -0.9 V, and -1.0 V.

[0071] The PFOA removal effect of different voltages in the above embodiment 2 and embodiment 5 is shown in Figure 5 The results show that as the voltage increases, the PFOA removal rate gradually increases, and the PFOA removal rate is the highest at -0.8 V. As the voltage continues to increase, the side reaction rate of generating H2 and O2 by electrolysis of water increases, which competes with the main reaction of H2O2 generation. Therefore, the PFOA removal effect is relatively excellent at -0.8 V.

[0072] Embodiment 6

[0073] The test operation steps of the above embodiment 2 and embodiment 6 are the same as those of embodiment 2, except that the recycling number of FeS2-MOF@C catalyst is different.

[0074] The PFOA removal effect and defluorination rate of FeS2-MOF@C catalyst with different recycling numbers in the above embodiment 2 and embodiment 6 are shown in Figure 6, the results show that the removal rate of PFOA is 100% within 3 hours and the defluorination rate is 76% in the first use; the removal rate can still be maintained at 94% and the defluorination rate at 71% after being used for three times; the removal rate is 87% and the defluorination rate is 67% when being used for the fourth time, which indicates that the system has good stability.

[0075] Comparative Example 3

[0076] The operation steps of the example are the same as those of Example 2, except that the counter electrode is replaced by a platinum sheet (Pt) electrode with the same area.

[0077] In the above Examples 2 and Comparative Example 3, the PFOA removal effect of different counter electrodes is shown in the following figure Figure 7 , the results show that the removal effect of Pt electrode on PFOA is much smaller than that of BDD electrode under the same conditions, which is attributed to the fact that BDD electrode can be used to capture the electrons of carboxyl group of PFOA, and then make the unstable carboxyl group of PFOA become CO2, which is beneficial to the degradation of active oxygen substances generated by the decomposition of PFOA by H2O2, and Pt electrode cannot realize this process, which confirms the role of BDD electrode in the electro-Fenton degradation system.

[0078] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. Use of a heterogeneous Fenton catalyst for the degradation of poly- and / or perfluorinated compounds, characterized in that, The preparation method of the heterogeneous Fenton catalyst comprises the following steps: (1) calcining the MOF material under a non-oxidizing atmosphere to obtain a carbonized MOF material; (2) using the carbonized MOF material obtained in step (1) as a template, FeSO 4、 Na2S2O3 and sulfur as raw materials, FeS2 is synthesized by a hydrothermal method, and a heterogeneous Fenton catalyst templated by a carbonized MOF material is obtained. The high surface area and pore structure of the MOF provide good carrier support, which is conducive to the uniform dispersion and immobilization of FeS2, thereby enhancing the stability and catalytic activity of the catalyst; The MOF material is a MOF-74 material synthesized from raw materials FeSO4·7H2O and 2,5-dihydroxyterephthalic acid.

2. Use according to claim 1, wherein The application is a three-electrode system electro-Fenton method for degrading and removing polyfluorinated and / or perfluorinated compound organic pollutants.

3. Use according to claim 2, wherein the compound is ###0002### Specifically, the application is as follows: a copper-deposited graphite felt is used as a working electrode, a boron-doped diamond electrode is used as a counter electrode, an Ag / AgCl electrode is used as a reference electrode, Na2SO4 is used as an electrolyte, the heterogeneous Fenton catalyst and the pollutants are added to the electrolyte for dispersion; the working electrode is used to reduce O2 in the aqueous solution to generate H2O2, and the heterogeneous Fenton catalyst is used to accelerate the decomposition of H2O2, thereby catalyzing the generation of more active oxygen substances, so as to realize efficient degradation of the pollutants.

4. Use according to claim 2 or 3, wherein the compound is ###0002### The mass-volume ratio of the heterogeneous Fenton catalyst to the electrolyte divided by the concentration of the organic pollutants is 30-60; the voltage applied in the electro-Fenton method is -0.5~-1.0 V, the reaction time is less than 3 hours, and the aeration rate is 2.5 L / min.

5. The use according to claim 1, wherein In step (1), the MOF material is prepared by a microwave method.

6. The use according to claim 5, wherein the compound is ###0002### The synthesis conditions of the microwave method are as follows: time 20-40 minutes, power 50-150 W / pot, and temperature 100-140℃.

7. The use according to claim 1, wherein In step (1), the calcination temperature is 400-600℃, the heating rate is 4-6℃ / min, and the holding time is 1-3 hours.

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