Application of FeCo bimetallic alloy catalyst in activated persulfate degradation of chlorinated organic pollutants

Abstract

This invention discloses an FeCo bimetallic alloy catalyst, its preparation method, and its applications, belonging to the field of catalysis technology. The FeCo bimetallic alloy catalyst provided by this invention comprises biochar and an iron-cobalt alloy supported on the biochar. This invention uses biochar as a support, which can stably support and disperse the iron-cobalt alloy. Iron can transfer electrons to chlorinated organic pollutants for reductive dechlorination, and both iron and cobalt can activate persulfate to generate singlet oxygen, attacking the phenolic hydroxyl groups on chlorinated organic pollutants and their dechlorination products, achieving the mineralization of chlorinated organic pollutants. In this process, reduction coupled with oxidation occurs simultaneously, enabling the efficient removal of chlorinated organic pollutants from water.

Description

Technical Field

[0001] This invention belongs to the field of catalysis technology, and particularly relates to an FeCo bimetallic alloy catalyst, its preparation method, and its application. Background Technology

[0002] Chlorophenols are widely used in herbicides, disinfectants, pesticides, papermaking, and plastics industries. They have been detected in various environmental media, including waste sludge, groundwater, surface water, and wastewater. Studies have shown that chlorophenols possess genotoxicity, hepatotoxicity, immunotoxicity, neurotoxicity, cardiotoxicity, and carcinogenic risks. Due to their threats to the environment and health, they have been listed as priority pollutants for control. However, the high electronegativity of chlorine atoms, forming stable covalent bonds with carbon atoms, results in a robust molecular structure, strong resistance to biodegradation, photodegradation, and chemical decomposition, and bioaccumulation, posing significant threats to the ecological environment and human health. Chlorinated organic compounds have a certain degree of volatility or water solubility, allowing them to migrate long distances through the atmosphere, water bodies, and organisms, expanding the scope of pollution. Although the production of many chlorinated pollutants (such as DDT and PCBs) has been restricted or banned, their large-scale use over the past decades has led to their continued release into the environment through reservoirs such as soil, sediments, and organisms. Conventional physical and chemical methods (such as adsorption and oxidation) are costly and have limited efficiency; bioremediation requires the screening of specific degrading bacteria, has a long cycle, and is limited by environmental conditions. Chlorinated compounds in deep soil, groundwater, and sediments are difficult to completely remove, resulting in their long-term presence in the environment. Therefore, the development of effective dechlorination methods has received increasing attention.

[0003] Zero-valued iron (ZVI) is a widely used material for water and soil remediation, and has been used to treat many environmental pollutants, including chlorinated hydrocarbons (CHCs), polychlorinated biphenyls (PCBs), chlorinated pesticides, pharmaceuticals, nitro aromatic compounds, phenols, and metals. ZVI-based materials show great application potential due to their ease of preparation, modification, and compounding. However, in addition to poor electron selectivity, ZVI is also prone to aggregation, passivation, and corrosion, which greatly limits its application in in-situ groundwater remediation. As a reducing agent or electron donor, almost all methods strive to improve or seek a balance between the following two points: (1) retain as many electrons as possible in the composite; (2) improve the transfer of electrons to pollutants. There are currently three main methods to improve the performance of ZVI-based materials: (1) optimizing the structure and morphology of ZVI, including micron ZVI (mZVI) and nano ZVI; (2) modifying ZVI by doping with a second element (metal or heteroatom) or organic polymer and surfactant; and (3) preparing composite materials by fixing ZVI on a solid porous carrier material.

[0004] Metal-modified ZVI (M-ZVI) is a commonly used modification method, mainly involving the incorporation of noble metals (such as Pd, Pt, Au, and Rh) or non-noble metals (such as Al, Mg, Ni, and Cu) into ZVI to produce bimetallic compounds. Due to various factors, such as the type of dopant metal, doping method, doping ratio, and doping sequence, M-ZVI exhibits different physicochemical properties (i.e., shape, size, composition, and surface chemistry). However, using noble metals (such as Pt and Ag) or non-noble metals (such as Ni and Cu) as dopant metals can lead to the leaching of metal ions, which may cause secondary pollution, and noble metals are expensive, resulting in high costs. In addition, due to van der Waals forces, high surface energy and intrinsic magnetism, M-ZVI tends to aggregate into large particles, which limits its reactivity and mobility; M-ZVI is more prone to passivation or deactivation, which reduces its stability and lifetime and complicates storage; M-ZVI has relatively low selectivity and is prone to side reactions, such as HER or the influence of other interfering ions, which significantly reduces its cycling ability and long-term reduction ability. Summary of the Invention

[0005] In order to overcome at least one of the problems existing in the prior art, one of the objectives of the present invention is to provide an FeCo bimetallic alloy catalyst, which is a highly efficient, stable, and low-cost iron-based catalyst, especially capable of efficiently and stably removing chlorinated organic pollutants from water.

[0006] The second objective of this invention is to provide a method for preparing the above-mentioned FeCo bimetallic alloy catalyst.

[0007] The third objective of this invention is to provide an application of the above-mentioned FeCo bimetallic alloy catalyst.

[0008] The fourth objective of this invention is to provide a method for removing chlorinated organic pollutants from water.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A first aspect of the present invention provides an FeCo bimetallic alloy catalyst comprising biochar and an iron-cobalt alloy supported on the biochar.

[0010] This invention loads an iron-cobalt alloy onto biochar, giving the catalyst excellent redox properties. The dual active sites greatly improve the activation efficiency of persulfate, and the activation generates a large number of free radicals, ultimately enabling the catalyst to achieve rapid and efficient removal of chlorinated organic pollutants in water through reduction dehalogenation and free radical oxidation.

[0011] Preferably, the iron-cobalt alloy is a petal-shaped iron-cobalt alloy.

[0012] Controlling the formation of petal-shaped iron-cobalt alloys can increase the specific surface area of ​​the catalyst, thereby promoting more thorough contact between the catalyst and pollutants, improving the activation efficiency of bimetallic active sites for persulfate, generating more free radicals, and more effectively enhancing the removal of pollutants.

[0013] Preferably, in the petal-shaped iron-cobalt alloy, the average lateral dimension of each petal is 100~200nm and the average thickness is 0.1~10nm.

[0014] Preferably, the molar ratio of iron to cobalt in the iron-cobalt alloy is 1:(0.1~2); more preferably 1:(0.2~1.2); even more preferably 1:(0.4~0.7).

[0015] Preferably, the FeCo bimetallic alloy catalyst has an average particle size of 1~2 μm.

[0016] A second aspect of the present invention provides a method for preparing the FeCo bimetallic alloy catalyst as described in the first aspect of the present invention, comprising the following steps: mixing an iron source, a cobalt source, a biochar source and a pore-forming agent, and performing pyrolysis reduction in a protective gas atmosphere to obtain the FeCo bimetallic alloy catalyst.

[0017] This invention utilizes the thermal reduction of biochar source to reduce iron and cobalt sources to zero-valent iron and cobalt in a one-pot process to form an iron-cobalt alloy. Furthermore, the biochar source contains abundant carbon elements, which can form biochar after pyrolysis and reduction and load the reduced iron-cobalt alloy.

[0018] Preferably, the holding temperature for pyrolysis reduction is 800~1000℃; more preferably 850~950℃; and even more preferably 880~920℃.

[0019] Preferably, the heat preservation time for pyrolysis reduction is 0.5~5h; more preferably 1~3h; and even more preferably 1.5~2.5h.

[0020] Preferably, the heating rate of the pyrolysis reduction is 3~7℃ / min; more preferably 4~6℃ / min; and even more preferably 4.5~5.5℃ / min.

[0021] Preferably, the molar ratio of the iron source to the cobalt source is 1:(0.1~2); more preferably 1:(0.2~1.2); even more preferably 1:(0.4~0.7).

[0022] Preferably, the mass ratio of the iron source to the biochar source is 1:(0.3~2); more preferably 1:(0.5~1.5); even more preferably 1:(0.6~1.2).

[0023] Preferably, the mass ratio of the iron source to the pore-forming agent is 1:(0.3~2); more preferably 1:(0.5~1.5); even more preferably 1:(0.6~1.2).

[0024] Preferably, the iron source includes at least one of ferric chloride, ferric sulfate, or ferric nitrate; more preferably, the iron source is selected from ferric chloride (FeCl3).

[0025] Preferably, the cobalt source includes at least one of cobalt chloride, cobalt sulfate, or cobalt nitrate; more preferably, the cobalt source is selected from cobalt chloride; and even more preferably, cobalt chloride hexahydrate (CoCl2·6H2O).

[0026] Preferably, the biochar source includes at least one of soybean residue, glucose, or straw; more preferably, the biochar source is selected from soybean residue.

[0027] Preferably, the pore-forming agent includes at least one of zinc chloride, carbon black, or silicon carbide; more preferably, the pore-forming agent is selected from zinc chloride (ZnCl2).

[0028] In some embodiments of the present invention, the protective gas includes at least one of nitrogen, argon, or helium; more specifically, the protective gas is selected from argon.

[0029] In some embodiments of the present invention, after the pyrolysis reduction, the mixture is cooled to room temperature in a protective gas atmosphere; specifically, the room temperature is 25±5°C.

[0030] In some embodiments of the present invention, after cooling, washing and drying are also performed; the washing reagents can be water and anhydrous ethanol; the washing can be performed 2 to 3 times.

[0031] A third aspect of the present invention provides the application of the FeCo bimetallic alloy catalyst as described in the first aspect of the present invention in the activated persulfate degradation of chlorinated organic pollutants.

[0032] Most chlorinated organic pollutants (COCs) are extremely toxic, bioaccumulative, and resistant to degradation. The widespread use and high toxicity of COCs pose a serious threat to the environment and human health. The FeCo bimetallic alloy catalyst of this invention can achieve the effective degradation of such pollutants.

[0033] Preferably, the chlorinated organic pollutant includes at least one of 2,4,6-trichlorophenol, 2,4-dichlorophenol, 2-chlorophenol, or chloramphenicol; in some embodiments of the present invention, the chlorinated organic pollutant is selected from 2,4,6-trichlorophenol.

[0034] Preferably, the persulfate includes at least one of sodium persulfate, potassium persulfate, or ammonium persulfate; in some embodiments of the present invention, the persulfate is selected from sodium persulfate.

[0035] The fourth aspect of the present invention provides a method for removing chlorinated organic pollutants from water, comprising the following steps: mixing water containing chlorinated organic pollutants, persulfate, and the FeCo bimetallic alloy catalyst described in the first aspect of the present invention to form a degradation reaction system, thereby removing chlorinated organic pollutants from the water through a degradation reaction.

[0036] Preferably, the concentration of the chlorinated organic pollutant in the degradation reaction system is 10~100 mg / L; more preferably 30~80 mg / L; even more preferably 40~60 mg / L.

[0037] Preferably, the concentration of persulfate in the degradation reaction system is 0.5~4 mmol / L; more preferably 1~3 mmol / L; even more preferably 1.5~2.5 mmol / L.

[0038] Preferably, the concentration of the FeCo bimetallic alloy catalyst in the degradation reaction system is 0.05~0.2 g / L; more preferably 0.07~0.15 g / L; and even more preferably 0.08~0.12 g / L.

[0039] Preferably, the chlorinated organic pollutant includes at least one of 2,4,6-trichlorophenol, 2,4-dichlorophenol, 2-chlorophenol, or chloramphenicol; in some embodiments of the present invention, the chlorinated organic pollutant is selected from 2,4,6-trichlorophenol.

[0040] Preferably, the persulfate includes at least one of sodium persulfate, potassium persulfate, or ammonium persulfate; in some embodiments of the present invention, the persulfate is selected from sodium persulfate.

[0041] The beneficial effects of this invention are as follows: This invention uses biochar as a carrier, which can stably load and disperse iron-cobalt alloy. Iron can transfer electrons to chlorinated organic pollutants for reduction and dechlorination. Both iron and cobalt can activate persulfate to generate singlet oxygen, which attacks the phenolic hydroxyl groups on chlorinated organic pollutants and their dechlorination products, thereby achieving the mineralization of chlorinated organic pollutants. In this process, reduction and oxidation occur simultaneously, which can achieve efficient removal of chlorinated organic pollutants in water. Attached Figure Description

[0042] Figure 1 This is a scanning electron microscope image of the FeCo@BC-1:1 catalyst prepared in Example 1 of the present invention.

[0043] Figure 2This is a scanning electron microscope image of the Fe@BC catalyst prepared in Comparative Example 1 of this invention.

[0044] Figure 3 This is a scanning electron microscope image of the Co@BC catalyst prepared in Comparative Example 2 of the present invention.

[0045] Figure 4 The cyclic voltammetry curves are of the catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention.

[0046] Figure 5 The diagram shows the effect of the catalysts prepared in Examples 1-3 and Comparative Examples 1-2 of this invention on the degradation of 2,4,6-trichlorophenol by activated persulfate. Detailed Implementation

[0047] The following specific embodiments further illustrate the content of the present invention in detail. It should also be understood that the following embodiments are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the principles described herein are all within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make selections within a suitable range based on the description herein, and are not intended to be limited to the specific data in the examples below. Unless otherwise specified, the raw materials, reagents, or apparatus used in the following embodiments and comparative examples can be obtained from conventional commercial sources or by existing known methods.

[0048] Example 1 A FeCo bimetallic alloy catalyst is prepared by the following steps: FeCl3 (2g, 0.0123mol), CoCl2·6H2O (2.928g, 0.0123mol), and ZnCl2 (2g, 0.0147mol) were added to a 50mL beaker containing 6mL of ultrapure water and sonicated for 10 minutes to ensure complete dissolution. Then, 2g of dried soybean residue was added to the mixture, and the mixture was vigorously stirred until a paste-like mixture was formed. This paste-like mixture was transferred to a ceramic boat and placed in a tube furnace. The temperature was increased to 900℃ at 5℃ / min under an argon atmosphere and maintained at 900℃ for 2 hours to achieve high-temperature reduction of the metal. After pyrolysis, the argon atmosphere was maintained until cooling to room temperature. Then, the mixture was cooled to room temperature under an argon atmosphere. Finally, the product was washed 2-3 times alternately with oxygen-free ultrapure water and anhydrous ethanol, and dried to obtain the biochar-supported nanopetal-shaped FeCo@BC-1:1 bimetallic alloy catalyst.

[0049] Example 2 A FeCo bimetallic alloy catalyst is prepared by the following steps: FeCl3 (2.5952 g, 0.016 mol), CoCl2·6H2O (1.9036 g, 0.008 mol), and ZnCl2 (2 g, 0.0147 mol) were added to a 50 mL beaker containing 6 mL of ultrapure water and sonicated for 10 minutes to ensure complete dissolution. Then, 2 g of dried soybean residue was added to the mixture, and the mixture was vigorously stirred until a paste-like mixture was formed. This paste-like mixture was transferred to a ceramic boat and placed in a tube furnace. The temperature was increased to 900 °C at 5 °C / min under an argon atmosphere and maintained at 900 °C for 2 hours to achieve high-temperature reduction of the metal. After pyrolysis, the argon atmosphere was maintained until cooling to room temperature. Then, the mixture was cooled to room temperature under an argon atmosphere. Finally, the product was washed 2-3 times alternately with oxygen-free ultrapure water and anhydrous ethanol, and dried to obtain the biochar-supported nanopetal-shaped FeCo@BC-2:1 bimetallic alloy catalyst.

[0050] Example 3 A FeCo bimetallic alloy catalyst is prepared by the following steps: FeCl3 (3.1142 g, 0.0192 mol), CoCl2·6H2O (1.1422 g, 0.0048 mol), and ZnCl2 (2 g, 0.0147 mol) were added to a 50 mL beaker containing 6 mL of ultrapure water and sonicated for 10 minutes to ensure complete dissolution. Then, 2 g of dried soybean residue was added to the mixture, and the mixture was vigorously stirred until a paste-like mixture was formed. This paste-like mixture was transferred to a ceramic boat and placed in a tube furnace. The temperature was increased to 900 °C at 5 °C / min under an argon atmosphere and maintained at 900 °C for 2 hours to achieve high-temperature reduction of the metal. After pyrolysis, the argon atmosphere was maintained until cooling to room temperature. Then, the mixture was cooled to room temperature under an argon atmosphere. Finally, the product was washed 2-3 times alternately with oxygen-free ultrapure water and anhydrous ethanol, and dried to obtain the biochar-supported nano-petal-shaped FeCo@BC-4:1 bimetallic alloy catalyst.

[0051] Comparative Example 1 An Fe metal catalyst, prepared by the following steps: FeCl3 (4 g, 0.0246 mol) and ZnCl2 (2 g, 0.0147 mol) were added to a 50 mL beaker containing 6 mL of ultrapure water and sonicated for 10 minutes to ensure complete dissolution. Then, 2 g of dried soybean residue was added to the mixture, and the mixture was vigorously stirred until a paste-like consistency was formed. This paste-like mixture was transferred to a ceramic boat and placed in a tube furnace. The temperature was increased to 900 °C at 5 °C / min under an argon atmosphere and maintained at 900 °C for 2 hours to achieve high-temperature reduction of the metal. After pyrolysis, the argon atmosphere was maintained until cooling to room temperature. Then, the mixture was cooled to room temperature under an argon atmosphere. Finally, the product was washed 2-3 times alternately with oxygen-free ultrapure water and anhydrous ethanol, and dried to obtain the biochar-supported zero-valent iron nanoarray Fe@BC catalyst.

[0052] Comparative Example 2 A Co metal catalyst, prepared by the following steps: CoCl₂•₆H₂O (5.856 g, 0.0246 mol) and ZnCl₂ (2 g, 0.0147 mol) were added to a 50 mL beaker containing 6 mL of ultrapure water and sonicated for 10 minutes to ensure complete dissolution. Then, 2 g of dried soybean residue was added to the mixture, and the mixture was vigorously stirred until a paste-like consistency was formed. This paste-like mixture was transferred to a ceramic boat and placed in a tube furnace. The temperature was increased to 900 °C at 5 °C / min under an argon atmosphere and maintained at 900 °C for 2 hours to achieve high-temperature reduction of the metal. After pyrolysis, the argon atmosphere was maintained until cooling to room temperature. Then, the mixture was cooled to room temperature under an argon atmosphere. Finally, the product was washed 2-3 times alternately with oxygen-free ultrapure water and anhydrous ethanol, and dried to obtain the biochar-supported zero-valent cobalt nanoflower Co@BC catalyst.

[0053] Performance testing (1) The catalyst samples prepared in each example and comparative example were characterized by scanning electron microscopy (SEM).

[0054] (2) The cyclic voltammetry curves of the catalyst samples prepared in each example and comparative example were tested. 100mM sodium sulfate solution was used as the electrolyte for the test. Sodium persulfate was also added during the test to participate in the reaction on the electrode surface to obtain the cyclic voltammetry curves of the materials.

[0055] (3) The pollutant removal effect of the catalyst samples prepared in each example and comparative example was tested. The specific steps are as follows: In water containing 50 mg / L of 2,4,6-trichlorophenol, the catalyst sample and sodium persulfate (Na2S2O8) were added. The amount of catalyst sample added was 0.1 g / L, and the amount of sodium persulfate (Na2S2O8) added was 2 mmol / L. After reacting for 2 hours, the removal rate and dechlorination rate of 2,4,6-trichlorophenol were tested. At the same time, the soybean residue was pyrolyzed according to the method of Example 1 to obtain BC sample. The BC sample was tested as described above. A control group was set up with no catalyst sample added and only 2 mmol / L sodium persulfate added, which was denoted as PDS.

[0056] Figure 1 This is a scanning electron microscope image of the FeCo@BC-1:1 catalyst prepared in Example 1 of the present invention; Figure 2 This is a scanning electron microscope image of the Fe@BC catalyst prepared in Comparative Example 1 of the present invention. Figure 3 This is a scanning electron microscope (SEM) image of the Co@BC catalyst prepared in Comparative Example 2 of this invention. Figure 1 As shown, nano-petals, composed of an iron-cobalt alloy, are clearly visible growing on the catalyst. Each petal has an average lateral dimension of 100–200 nm and an average thickness of 0.1–10 nm. These petal-shaped iron-cobalt alloys serve as the active component of the catalyst, supported on biochar particles. The overall average particle size of the catalyst sample is 1–2 μm. Figure 1 It is evident that the biochar-supported nanopetal-shaped FeCo@BC bimetallic alloy catalyst can be successfully synthesized using the method of Example 1. Figure 2 It can be seen that the Fe@BC catalyst prepared in Comparative Example 1 exhibits a needle-like nanoarray structure. From Figure 3 It can be seen that the Co@BC catalyst prepared in Comparative Example 2 is nanosheet-like and coated on biochar.

[0057] The redox performance of different Fe-based catalysts for persulfate (PDS) was evaluated using cyclic voltammetry. In the cyclic voltammetry, the reduction-related broad peak of PDS appeared at approximately -0.80 to -1.20 V, and the oxidation broad peak appeared at -0.75 to -0.50 V. Figure 4 This is a cyclic voltammogram of the catalysts prepared in Example 1 and Comparative Examples 1-2 of the present invention. From... Figure 4It can be seen that the FeCo@BC bimetallic alloy catalyst of Example 1 exhibits obvious reduction and oxidation peaks at -0.80 to -1.20 V and -0.75 to -0.50 V, with equal peak heights, indicating that the catalyst has excellent redox performance for PDS. The Fe@BC catalyst of Comparative Example 1 shows reduction and oxidation peaks at -1.0 V to -1.4 V and -0.6 V to -0.3 V, but the peak heights are much lower than the reduction and oxidation peaks of the FeCo@BC catalyst of Example 1; while the Co@BC catalyst of Comparative Example 2 has almost no reduction and oxidation peaks. The comparison of the cyclic voltammetry curves of the three catalysts shows that the biochar-supported nano-petal-shaped FeCo@BC bimetallic alloy catalyst in Example 1 has better PDS catalytic performance, and this catalyst can effectively remove chlorinated organic aromatic pollutants from water.

[0058] Figure 5 The graph shows the effect of the catalysts prepared in Examples 1-3 and Comparative Examples 1-2 of this invention on the degradation of 2,4,6-trichlorophenol by activated persulfate. Figure 5 As can be seen, after two hours of reaction, the FeCo@BC-1:1, FeCo@BC-2:1, and FeCo@BC-4:1 catalysts of Examples 1-3 achieved removal rates of 95%, 99%, and 97% respectively in the degradation of 2,4,6-trichlorophenol by activated PDS, with dechlorination rates of 47%, 52%, and 43% respectively. All three catalysts can effectively degrade 2,4,6-trichlorophenol, with the 2:1 FeCo ratio in Example 2 showing better results. In contrast, the Fe@BC catalyst of Comparative Example 1 and the Co@BC catalyst of Comparative Example 2 only achieved removal rates of 81% and 59% respectively in the degradation of 2,4,6-trichlorophenol by activated PDS, with dechlorination rates of only 31% and 2.5%, indicating that their effectiveness in removing chlorinated organic aromatic pollutants was significantly lower than that of Examples 1-3.

[0059] In summary, this invention uses biochar as a carrier, which can stably load and disperse iron-cobalt alloy. Iron can transfer electrons to chlorinated organic pollutants for reduction and dechlorination. Both iron and cobalt can activate persulfate to generate singlet oxygen, which attacks the phenolic hydroxyl groups on chlorinated organic pollutants and their dechlorination products, thereby achieving the mineralization of chlorinated organic pollutants. In this process, reduction and oxidation occur simultaneously, which can achieve efficient removal of chlorinated organic pollutants from water.

Claims

1. Use of a FeCo bimetallic alloy catalyst in the activation of persulfate for the degradation of chlorinated organic pollutants, characterized in that, The FeCo bimetallic alloy catalyst comprises biochar and an iron-cobalt alloy supported on the biochar; the iron-cobalt alloy is a petal-shaped iron-cobalt alloy. The FeCo bimetallic alloy catalyst is prepared by a method comprising the following steps: mixing an iron source, a cobalt source, a biochar source and a pore-forming agent, and performing pyrolysis reduction in a protective gas atmosphere to obtain the FeCo bimetallic alloy catalyst; the pore-forming agent is selected from zinc chloride; The holding temperature for the pyrolysis reduction is 800~1000℃; the holding time for the pyrolysis reduction is 0.5~5h; the heating rate for the pyrolysis reduction is 3~7℃ / min; the molar ratio of the iron source to the cobalt source is 1:(0.1~2); the mass ratio of the iron source to the biochar source is 1:(0.3~2); and the mass ratio of the iron source to the pore-forming agent is 1:(0.3~2).

2. The application according to claim 1, characterized in that, The molar ratio of iron to cobalt in the iron-cobalt alloy is 1:(0.1~2). And / or, the average particle size of the FeCo bimetallic alloy catalyst is 1~2μm.

3. The application according to claim 1, characterized in that, In the petal-shaped iron-cobalt alloy, the average lateral dimension of each petal is 100~200nm and the average thickness is 0.1~10nm.

4. The application according to claim 1, characterized in that, The iron source includes at least one of ferric chloride, ferric sulfate, or ferric nitrate. And / or, the cobalt source includes at least one of cobalt chloride, cobalt sulfate, or cobalt nitrate; And / or, the biochar source includes at least one of soybean residue, glucose, or straw.

5. The application according to claim 1, characterized in that, The chlorinated organic pollutants include at least one of 2,4,6-trichlorophenol, 2,4-dichlorophenol, 2-chlorophenol, or chloramphenicol; And / or, the persulfate includes at least one of sodium persulfate, potassium persulfate, or ammonium persulfate.

6. The application according to claim 1, characterized in that, The application includes the following steps: mixing water containing chlorinated organic pollutants, persulfate, and FeCo bimetallic alloy catalyst to form a degradation reaction system, and removing chlorinated organic pollutants from the water through the degradation reaction.

7. The application according to claim 6, characterized in that, The concentration of the chlorinated organic pollutants in the degradation reaction system is 10~100 mg / L; And / or, the concentration of the persulfate in the degradation reaction system is 0.5~4 mmol / L; And / or, the concentration of the FeCo bimetallic alloy catalyst in the degradation reaction system is 0.05~0.2 g / L.

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