Application of imine bond orientation regulation and control monatomic coordination environment for enhancing removal of organic pollutants

Abstract

The invention relates to an application of an imine bond orientation regulation monatomic coordination environment to enhance removal of organic pollutants, and relates to an application of catalytic degradation of organic pollutants. The preparation method comprises the following main steps: preparing two covalent organic framework substrates by using Knoevenagel condensation reaction through simple regulation and control of organic ligand functional group pairing; uniformly dispersing the obtained covalent organic framework material in an organic solvent, stirring and mixing with an organic solvent dissolved with metal ions, and separating and drying to obtain two monatomic catalysts. The regulated monatomic catalyst obtained by the invention shows a better removal effect on organic pollutants, is simple and convenient to operate and high in feasibility, and has good environmental and social benefits.

Description

Technical Field

[0001] This invention relates to the field of catalytic water treatment technology for organic pollutants, and in particular to the application of an imine bond orientation-regulated single-atom coordination environment to enhance the removal of organic pollutants. Background Technology

[0002] Organic pollutants are contaminants that exist in the environment in the form of organic compounds. They are often toxic, persistent, and bioaccumulative. Their sources are widespread, commonly found in industrial wastewater, pesticides, and plastic waste. Their hazards are diverse; they not only pollute water, soil, and air, but can also enter the human body through the food chain, damaging organs such as the liver and kidneys, and even having carcinogenic, teratogenic, and mutagenic effects. They also threaten the survival of plants and animals in ecosystems, destroying biodiversity. In recent years, my country has placed increasing emphasis on the control of organic pollutants, establishing a series of monitoring and control mechanisms and related laws and regulations. However, organic pollutants are difficult to remove; therefore, how to remove organic pollutants from water in a green and efficient manner has become a current research hotspot.

[0003] The activation technology based on persulfate is a relatively new water treatment method for removing organic pollutants from the aquatic environment. In this process, persulfate is activated to generate reactive oxygen species (ROSs), which break down the pollutants, further transforming them into smaller molecules or mineralizing them. This technology has advantages such as fast reaction rate, wide applicability, significant treatment effect on high-concentration and recalcitrant organic wastewater, and environmental friendliness. The ROSs generated in this process mainly include hydroxyl radicals (·OH) and sulfate radicals (SO42-). - ·), superoxide anion (·O2-) and other free radical ROSs, as well as singlet oxygen ( 1 Non-radical ROSs include O2 and high-valence metal species. Among these, radical ROSs have limited effectiveness in practical applications due to their selectivity, while non-radical ROSs... 1While oxygen (O2) can selectively degrade target pollutants, its degradation products and intermediates are often highly toxic. High-valence metal species, a new type of non-radical reactive oxygen species (ROSs), have shown promising results in the treatment of various water pollutants. Compared to traditional ROSs, high-valence metal species typically possess lower oxidation potentials, longer lifespans, and higher steady-state concentrations, making them an ideal class of reactive oxygen species. Therefore, regulating the activation and targeting of persulfate to selectively generate high-valence metal species is crucial for pollutant degradation. Single-atom catalysts refer to materials with catalytically active materials formed by uniformly dispersing metal atoms as individual atoms on or within a support. The presence of metal active components in single-atom form overcomes the size limitations of metal particles in traditional catalysts, enabling more efficient utilization of metal resources and reducing catalyst costs. In particular, by selecting different metal single atoms, supports, and controlling synthesis conditions, the structural characteristics of single-atom catalysts, such as their coordination environment, can be altered, thereby achieving the regulation of their catalytic performance.

[0004] Covalent organic frameworks (COFs), as supports for single-atom catalysts (SACs), play a decisive role in the electronic structure, active site stability, and catalytic performance of catalysts due to their coordination environment (i.e., the type, structure, and coordination number of coordinating atoms between the single-atom metal and the COF framework). Therefore, by coordinating and regulating the COF substrate, the chemical environment when the metal is supported can be altered, thereby controlling the types and proportions of reactive oxygen species during pollutant removal and influencing the pollutant removal activity.

[0005] However, current research on the influence of COF substrates on the activity mechanism and application of single-atom catalysts is still insufficient. Therefore, simple coordination regulation of COF substrates and exploration of the application of the resulting single-atom catalysts are of great significance for removing organic pollutants such as phenol from water. Summary of the Invention

[0006] To address the above technical problems, this invention provides an application of imine bond orientation regulation to enhance the removal of organic pollutants through single-atom coordination environment.

[0007] The purpose of this invention is to provide an application of imine bond orientation regulation to enhance the removal of organic pollutants through single-atom coordination environment, comprising the following steps:

[0008] (1) In the reaction solvent, the organic ligand containing the aldehyde terminal group and the organic ligand containing the amino terminal group are mixed evenly, and then the catalyst is added to obtain a mixture. After vacuum freezing degassing, the bottle mouth is sealed, and then heated to carry out the Knauvengay condensation reaction. After drying, the COF substrate material is obtained.

[0009] (2) The obtained COF substrate material is dispersed in an organic solvent and ultrasonically dispersed to obtain a COF substrate material dispersion: the COF substrate material dispersion and metal salt solution are mixed and reacted, the reaction solution is separated into solid and liquid phases and the solid phase is taken and vacuum dried to obtain a coordination-regulated covalent organic framework-based single-atom catalyst.

[0010] (3) Add the COF substrate material from step (1) and the covalent organic framework-based single-atom catalyst from step (2) to the aqueous solution containing organic pollutants, stir to achieve adsorption equilibrium, add persulfate, and take samples to monitor the residual concentration of organic pollutants, thereby achieving the removal of organic pollutants by enhancing the single-atom coordination environment under the control of imine bond orientation.

[0011] In some embodiments of the present invention, in step (1), the organic ligand containing the aldehyde terminal group is 2,2'-bipyridine-5,5'-dicarboxaldehyde and / or 1,3,5-tris-(4-formylphenyl)triazine;

[0012] The organic ligand containing the amino-terminal group is 5,5'-diamino-2,2'-bipyridine and / or 2,4,6-tris(4-aminophenyl)-1,3,5-triazine;

[0013] The molar ratio of the organic ligand containing the aldehyde terminal group to the organic ligand containing the amino terminal group is (1-3):(1.5-4.5).

[0014] In some embodiments of the present invention, in step (1), the reaction solvent includes one or more of o-dichlorobenzene, dioxane and mesitylene; further, dioxane and mesitylene are preferred, and the volume ratio of dioxane and mesitylene is 1:1.

[0015] Further, the ratio of the organic ligand containing the aldehyde terminal group, the organic ligand containing the amino terminal group, the reaction solvent, and the catalyst solution is: (10-20) mg : (10-20) mg : (1-2) mL : (0.1-0.3) mL.

[0016] The catalyst includes acetic acid, and the concentration of the catalyst is 4 mol / L-6 mol / L.

[0017] In some embodiments of the present invention, in step (1), the glass tube is vacuum-frozen and degassed by three liquid nitrogen freezing-thawing cycles to prevent excessive oxidation reactions from causing the generation of other byproducts.

[0018] In some embodiments of the present invention, in step (1), the temperature of the Knauvengel condensation reaction is 120-140°C and the reaction time is 72-120h.

[0019] In some embodiments of the present invention, step (1) further includes elution using an organic solvent, said organic solvent including at least one or two of tetrahydrofuran, acetone and n-hexane.

[0020] In some embodiments of the present invention, step (1) further includes a drying step, wherein the product is dried at a temperature of 60°C for 3-5 hours.

[0021] In some embodiments of the present invention, in step (2), the organic solvent includes one or more of methanol, ethanol, propanol, butanol, acetone and toluene;

[0022] The ultrasonic dispersion conditions are: temperature 30℃-50℃, ultrasonic time 15-30min.

[0023] The solvent for the metal salt solution is an organic solvent, which includes one or more of methanol, ethanol, propanol, butanol, acetone, and toluene.

[0024] The metal in the metal salt solution is selected from one or more of cobalt, iron, and nickel;

[0025] The salts in the metal salt solution include one or more of nitrates, chlorides, phosphates, and sulfates.

[0026] In some embodiments of the present invention, in step (2), the mass ratio of COF substrate material to metal salt is 1:1-3;

[0027] The concentration of the metal salt solution is 3-8 mg / ml;

[0028] The concentration of the COF substrate material dispersion is 1.5-3 mg / ml.

[0029] In some embodiments of the present invention, in step (2), the mixing reaction time is 12-14h, and the stirring speed during the reaction process is 200-400r / min;

[0030] The temperature for vacuum drying is 60-90℃.

[0031] In some embodiments of the present invention, the adsorption equilibrium time in step (3) is 20-30 min.

[0032] In some embodiments of the present invention, in step (3), the concentration of the persulfate is 1-2 mmol / L. The salt in the persulfate includes one or more of sulfate, nitrate, sulfate, and phosphate.

[0033] In some embodiments of the present invention, in step (3), the initial concentration of organic pollutants is 5-10 ppm; the organic pollutants include one or more of phenol, sulfamethoxazole, bisphenol A, and acetaminophen.

[0034] In step (3), the sampling and monitoring time is 0, 1, 3, 5, 10, 15, 20, 30, 45, and 60 minutes.

[0035] The technical solution of the present invention has the following advantages compared with the prior art:

[0036] This invention obtains two covalent organic framework substrate materials with similar structures by simple coordination regulation of organic ligands containing aldehyde terminal groups and organic ligands containing amino terminal groups. Then, metals are loaded onto the two covalent organic frameworks to obtain two single-atom catalysts with different activity effects. Finally, the obtained catalysts are used to catalytically degrade organic pollutants, thus demonstrating the application of metal-loaded covalent organic framework materials in the field of water pollution treatment.

[0037] The two covalent organic framework-based materials prepared in this invention are obtained by simply controlling the orientation of the imine bonds using two sets of ligands with opposite functional groups (RA and R'-B coordination versus R'-A and RB coordination). By controlling the coordination environment of the two covalent organic framework-based materials, differences are created, leading to an increase in the concentration and proportion of high-valence metal species in the two single-atom catalysts after metal loading, resulting in differences in the activity of the two single-atom catalysts in pollutant removal applications. This demonstrates that the types and proportions of reactive oxygen species during pollutant removal can be controlled through simple coordination regulation of organic ligands, thereby obtaining covalent organic framework-based single-atom catalytic materials with higher activity. This provides support for further research on fine-tuning of ligands to improve the activity of single-atom catalysts.

[0038] This invention provides a green, simple, efficient, and feasible method for novel single-atom catalysts, improving the overall performance of single-atom catalysts and showing great development potential and application prospects in the field of water treatment, thereby discovering more efficient covalent organic framework-based single-atom catalysts.

[0039] The catalyst preparation method in this invention is simple, effective, easy to operate, and low in cost, and has good environmental, social, and economic benefits. Attached Figure Description

[0040] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0041] Figure 1The image shows an XRD comparison of the substrate and catalyst of the single-atom catalytic material obtained before and after coordination regulation of the covalent organic framework obtained in the embodiments of the present invention.

[0042] Figure 2 The graph shows the phenol removal performance of the single-atom catalytic material obtained before and after coordination regulation of the covalent organic framework obtained in the embodiments of the present invention.

[0043] Figure 3 The figure shows the quenching results of phenol removal by the single-atom catalytic material obtained before coordination regulation of the covalent organic framework in the embodiments of the present invention.

[0044] Figure 4 The figure shows the quenching results of phenol removal by the single-atom catalytic material obtained by coordination regulation of the covalent organic framework obtained in the embodiments of the present invention.

[0045] Figure 5 The figure shows the results of single-atom catalytic material probe experiments on the generation and selectivity of high-valence metal species obtained before and after coordination regulation of the covalent organic framework obtained in the embodiments of the present invention.

[0046] Figure 6 The figure shows the fitting results of the quantitative high-valence metal species generation concentration obtained by single-atom catalytic material probe experiments before and after coordination regulation of the covalent organic framework obtained in the embodiments of the present invention. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0048] Example 1:

[0049] This embodiment provides an application of imine bond orientation regulation to enhance the removal of organic pollutants by controlling the single-atom coordination environment, comprising the following steps:

[0050] 1. Preparation of single-atom catalyst: (1) Weigh 12.7 mg of 2,2'-bipyridine-5,5'-dicarboxaldehyde and 14.2 mg of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine into a glass tube, add 1 mL of o-dichlorobenzene, and sonicate for 10 min to disperse it evenly. After sonication, add 0.1 mL of 6 mol / L acetic acid solution to catalyze the reaction.

[0051] (2) The glass tube was vacuum degassed by three cycles of liquid nitrogen freezing and thawing to prevent excessive oxidation and the formation of other byproducts, and then sealed by sintering. The sealed glass tube was placed in an oven at 120°C for 120 hours to undergo Knauven-Gail condensation until a yellow solid was formed at the bottom of the glass tube. After the reaction, the solid product in the glass bottle was obtained by vacuum filtration, washed with tetrahydrofuran until the washing liquid was colorless, rinsed once with n-hexane, and dried in an oven at 60°C to obtain a covalent organic framework material, denoted as TAPT. The obtained TAPT was structurally characterized, and the results are shown in […]. Figure 1 .

[0052] (3) Take 50 mg of TAPT in a 100 ml reaction flask, add 40 ml of anhydrous methanol, and sonicate for 20 min to obtain solution A; weigh 100 mg of cobalt chloride particles and dissolve them in 30 ml of anhydrous ethanol to obtain solution B. Under an environment of r = 300 r / min, slowly pour solution B into solution A and stir for 12 h to obtain a mixture. Wash the mixture with ultrapure water and filter to obtain the solid phase. Dry the obtained solid phase under vacuum at 60 °C to obtain a covalent organic framework-based cobalt single-atom catalyst, named TAPT-Co. The structure of the obtained TAPT-Co was characterized, and the results are shown in the figure. Figure 1 .

[0053] 2. Activation of PMS to degrade phenol: Weigh 5 mg TAPT-Co into an Erlenmeyer flask, add 50 ml of 5 mg / L phenol, and sonicate until the catalyst and phenol are completely mixed. Immediately place the flask in a magnetic stirrer and stir for 30 min until adsorption equilibrium is reached. Then, take 1 ml of the mixed liquid, filter it, and measure the phenol content using liquid chromatography, recording it as 0 min. Simultaneously, add 0.5 ml of 0.1 mol / L PMS and start timing immediately. Take 1 ml of samples at 1 min, 3 min, 5 min, 10 min, 20 min, 30 min, 45 min, and 60 min, filter them, and measure the phenol content using liquid chromatography. The experimental results are shown in [Figure number missing]. Figure 2 See Table 1.

[0054] 3. Quenching of reactive oxygen species: Weigh 5 mg TAPT-Co into an Erlenmeyer flask, add 50 ml of 5 mg / L phenol, and sonicate until the catalyst and phenol are completely mixed. Add 202.1 μl of pure methanol, 22.1 μl of furfuryl alcohol (FFA), 237.6 μl of tert-butanol, and 1 ml of 625 mmol / L carbon tetrachloride (CCl4) to the Erlenmeyer flask, and immediately place it in a magnetic stirrer and stir for 30 min until adsorption equilibrium is reached. Then, take 1 ml of the mixed liquid, filter it, and measure the phenol content by liquid chromatography, recording it as 0 min. At the same time, add 0.5 ml of 0.1 mol / L PMS and start timing immediately. Take 1 ml of samples at 1 min, 3 min, 5 min, 10 min, 20 min, 30 min, 45 min, and 60 min, filter them, and measure the phenol content by liquid chromatography. The experimental results are shown in [Figure number missing]. Figure 3 .

[0055] Example 2:

[0056] This embodiment describes an application of imine bond orientation regulation to enhance the removal of organic pollutants through single-atom coordination environment. Compared to Example 1, the difference lies in the added ligands and organic solvents; other operational methods are the same as in Example 1. It includes the following steps:

[0057] 1. Preparation of single-atom catalyst: (1) Weigh 11.2 mg of 5,5'-diamino-2,2'-bipyridine and 17.8 mg of 1,3,5-tris-(4-formylphenyl)triazine into a glass tube, add 0.7 ml of dioxane and 0.3 ml of mesitylene, and sonicate for 10 min to disperse them evenly. After sonication, add 0.1 mL of 6 mol / L acetic acid solution to catalyze the reaction.

[0058] (2) The glass tube was vacuum degassed by three cycles of liquid nitrogen freezing and thawing to prevent excessive oxidation and the formation of other byproducts. The tube was then sealed by firing. The sealed glass tube was placed in an oven at 120°C for 120 hours. After the reaction, a Knauven-Gail condensation reaction was performed in the oven, producing a yellow solid at the bottom of the tube. After the reaction, the solid product in the glass bottle was obtained by filtration, washed with tetrahydrofuran until the washing liquid was colorless, then rinsed with n-hexane, and dried in an oven at 60°C to obtain a covalent organic framework material, denoted as TFPT. The obtained TFPT was structurally characterized, and the results are shown in [Figure 1]. Figure 1 .

[0059] (3) Weigh 50 mg of TFPT into a 100 ml reaction flask, add 40 ml of anhydrous methanol, and sonicate for 20 min to obtain solution A. Weigh 100 mg of cobalt chloride particles and dissolve them in 30 ml of anhydrous ethanol to obtain solution B. Under an environment of r = 300 r / min, slowly pour solution B into solution A and stir for 12 h. Wash the mixture with ultrapure water and filter. Dry it under vacuum at 60 °C to obtain the material named TFPT-Co. The structure of the obtained TFPT-Co was characterized, and the results are shown in [Figure 1]. Figure 1 .

[0060] 2. Activation of PMS to degrade phenol: Weigh 5 mg TFPT-Co into an Erlenmeyer flask, add 50 ml of 5 mg / L phenol, and sonicate until the catalyst and phenol are completely mixed. Immediately place the flask in a magnetic stirrer and stir for 30 min until adsorption equilibrium is reached. Then, take 1 ml of the mixed liquid, filter it, and measure the phenol content using liquid chromatography, recording it as 0 min. Simultaneously, add 0.5 ml of 0.1 mol / L PMS and immediately start timing. Take 1 ml of samples at 1 min, 3 min, 5 min, 10 min, 20 min, 30 min, 45 min, and 60 min, filter them, and measure the phenol content using liquid chromatography. The experimental results are shown in [Figure number missing]. Figure 2 See Table 1.

[0061] 3. Quenching of reactive oxygen species: Weigh 5 mg TAPT-Co into an Erlenmeyer flask, add 50 ml of 5 mg / L phenol, and sonicate until the catalyst and phenol are completely mixed. Add 202.1 μl of pure methanol, 22.1 μl of furfuryl alcohol (FFA), 237.6 μl of tert-butanol (TBA), and 1 ml of 625 mmol / L carbon tetrachloride (CCl4) to the Erlenmeyer flask, and immediately place it in a magnetic stirrer and stir for 30 min until adsorption equilibrium is reached. Then, take 1 ml of the mixed liquid, filter it, and measure the phenol content by liquid chromatography, recording it as 0 min. At the same time, add 0.5 ml of 0.1 mol / L PMS and start timing immediately. Take 1 ml of samples at 1 min, 3 min, 5 min, 10 min, 20 min, 30 min, 45 min, and 60 min, filter them, and measure the phenol content by liquid chromatography. The experimental results are shown in [Figure number missing]. Figure 3 .

[0062] The catalytic performance of the single-atom catalyst provided in the above embodiments was tested, specifically by activating PMS to degrade phenol. The test was performed using liquid chromatography, where C0 represents the initial concentration and C represents the concentration at a certain moment. Specific results are shown in Table 1 and below. Figure 2 As shown:

[0063] Table 1. Activity data of single-atom catalysts activating PMS for phenol degradation

[0064]

[0065] The cobalt metal content of the single-atom catalyst provided in the above embodiments was tested by inductively coupled plasma mass spectrometry (ICP-MS), and the specific results are shown in Table 2 below:

[0066] Table 2. Metal content data in single-atom catalysts

[0067]

[0068] Figure 1 The images show the XRD patterns of the two covalent organic framework-based single-atom catalysts TAPT-Co and TFPT-Co prepared in the above embodiments, as well as the two covalent organic framework substrates TAPT and TFPT. It can be seen that the TAPT-Co and TFPT-Co obtained in the embodiments of the present invention have a certain degree of crystallinity and similar structures. Figure 2 The above examples show the activity diagrams of two single-atom catalysts TAPT-Co and TFPT-Co based on covalent organic frameworks, as well as the activation of PMS by TAPT and TFPT on the two covalent organic framework substrates for phenol degradation. It can be seen that the two substrates have almost no degradation activity for pollutants, while the degradation activity of the single-atom catalyst obtained by supporting metal on TFPT substrate after regulation is significantly increased.

[0069] Figure 3 and Figure 4 The figures show the quenching activity of the two single-atom catalysts prepared in the above examples for phenol. It can be seen that the active oxygen species involved differ slightly. Methanol (MeOH) is mainly used to quench hydroxyl radicals and sulfate radicals; furfuryl alcohol (FFA) is mainly used to quench singlet oxygen; tert-butanol (TBA) is mainly used to quench hydroxyl radicals; and carbon tetrachloride (CCl4) is mainly used to quench superoxide anions.

[0070] Figure 5 The figures show the results of probe experiments on high-valence metal species generation and selectivity of the single-atom catalytic material obtained before and after coordination regulation of the covalent organic framework in this embodiment of the invention. The regulated single-atom catalyst showed significantly higher yield and selectivity of high-valence metal species in the system (close to 100%).

[0071] Figure 6 The figure shows the fitting results of the quantitative high-valence metal species generation concentration obtained by single-atom catalytic material probe experiments before and after coordination regulation of the covalent organic framework obtained in the embodiments of the present invention.

[0072] PMSO was used as a probe to quantify high-valence metal species. After obtaining the data, the selectivity η was calculated using the consumption of PMSO and the production of PMSO2. The calculated selectivity was then substituted into the equation.

[0073]

[0074] according to Figure 6 The fitted curve in the middle can be used to obtain k obs Then according to the equation

[0075]

[0076] The concentration of high-valence metal species can be calculated. Calculations show that the concentrations of high-valence metal species produced by the covalent organic framework-based single-atom catalyst before and after regulation are 1.179E-6 and 1.634E-6 mM, respectively.

[0077] This indicates that the concentration of high-valence metal species produced by the covalent organic framework-based single-atom catalyst is higher after regulation, which in turn leads to higher activity and efficiency in pollutant removal applications.

[0078] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. The use of imine bond orientation to regulate the coordination environment of single atoms to enhance the removal of organic pollutants, characterized in that, The method comprises the following steps: (1) mixing an organic ligand containing an aldehyde group end group and an organic ligand containing an amino group end group in a reaction solvent, then adding a catalyst to obtain a mixed solution, vacuum freeze-drying, sealing the bottle mouth, then heating to perform a Knoevenagel condensation reaction to obtain a COF base material; (2) dispersing the obtained COF base material in an organic solvent to obtain a COF base material dispersion liquid by ultrasonic dispersion, mixing the COF base material dispersion liquid and a metal salt solution to perform a reaction, performing solid-liquid separation on the reaction liquid to obtain a solid phase, and vacuum drying to obtain a coordination-regulated covalent organic framework base monatomic catalyst; (3) adding the COF base material of step (1) and the coordination-regulated covalent organic framework base monatomic catalyst of step (2) to an aqueous solution containing an organic pollutant, stirring to achieve adsorption equilibrium, adding a persulfate salt, sampling to monitor the residual concentration of the organic pollutant, and realizing the removal of the organic pollutant by imine bond orientation regulation and monatomic coordination environment strengthening.

2. Use according to claim 1, characterized in that, In step (1), the organic ligand containing an aldehyde group end group is 2,2'-dipyridyl-5,5'-diformaldehyde and / or 1,3,5-tris-(4-formylphenyl)triazine; The organic ligand containing an amino group end group is 5,5'-diamino-2,2'-dipyridyl and / or 2,4,6-tris(4-aminophenyl)-1,3,5-triazine; The molar ratio of the organic ligand containing an aldehyde group end group to the organic ligand containing an amino group end group is (1-3):(1.5-4.5).

3. Use according to claim 1, characterized in that, In step (1), the reaction solvent comprises one or more of o-dichlorobenzene, dioxane and mesitylene; The catalyst comprises acetic acid, and the concentration of the catalyst is 4-6 mol / L.

4. Use according to claim 1, characterized in that, In step (1), the temperature of the Knoevenagel condensation reaction is 120-140 DEG C, and the reaction time is 72-120 h.

5. The use according to claim 1, characterized in that, In step (2), the organic solvent comprises one or more of methanol, ethanol, propanol, butanol, acetone and toluene; The solvent of the metal salt solution is an organic solvent, and the organic solvent comprises one or more of methanol, ethanol, propanol, butanol, acetone and toluene; The metal in the metal salt solution is selected from one or more of cobalt, iron and nickel; The salt in the metal salt solution comprises one or more of nitrate, chloride, phosphate and sulfate.

6. Use according to claim 1, characterized in that, In step (2), the mass ratio of the COF base material to the metal salt is 1:1-3; The concentration of the metal salt solution is 3-8 mg / ml; The concentration of the COF base material dispersion liquid is 1.5-3 mg / ml.

7. The use according to claim 1, characterized in that, In step (2), the mixing reaction time is 12-14 h, and the stirring speed during the reaction is 200-400 r / min; The temperature of the vacuum drying is 60-90 DEG C.

8. The use according to claim 1, characterized in that, In step (3), the adsorption equilibrium time is 20-30 min.

9. The use according to claim 1, characterized in that, In step (3), the concentration of the added persulfate salt is 1-2 mmol / L.

10. The use according to claim 1, characterized in that, In step (3), the initial concentration of the organic pollutant is 5-10 ppm; and the organic pollutant comprises one or more of phenol, sulfamethoxazole, bisphenol A and acetaminophen.

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