A pyranonitrile-based anionic porous material, preparation method thereof and application thereof

Abstract

The invention discloses a pyranonitrile anionic porous material, a preparation method and an application thereof. The method comprises the following steps: step 1: adding pyrone and an active methylene monomer into a reaction container, and obtaining a pyranonitrile intermediate 1 through Knoevenage condensation; step 2: adding the pyranonitrile intermediate 1 obtained in step 1 and an aldehyde derivative into a reaction container, and obtaining a pyranonitrile monomer 2 through Knoevenage condensation; step 3: adding the pyranonitrile monomer 2 obtained in step 2 into a reaction container, adding an oxidant, and obtaining a porous material 1; step 4: adding the porous material 1 obtained in step 3 into a reaction container, and adding a sulfonation reagent, and obtaining a final pyranonitrile anionic porous material. The pyranonitrile anionic porous material has ultrafast adsorption rate, high adsorption capacity and excellent reusability in removing organic dyes and pesticides, and has good application prospects and great application value in the field of water treatment.

Description

Technical Field

[0001] The present invention relates to a pyranonitrile anion-based porous material, a preparation method and an application thereof, and particularly relates to a preparation method of a pyranonitrile anion-based porous material for ultra-fast adsorption of pollutants in water, belonging to the technical field of porous material preparation and sewage treatment. Background Art

[0002] Clean, unpolluted water resources are crucial to humanity, yet parts of the world still lack freshwater resources. Furthermore, the rapidly increasing discharge of pollutants from chemical and agricultural production poses a serious threat to human health. Among these pollutants, cationic dyes and pesticides (including methylene blue, rhodamine B, paraquat, and diquat) have garnered widespread attention due to their stability, toxicity, and long-term negative impacts on human health and ecosystems. Therefore, developing a cost-effective and efficient method with excellent removal performance is crucial for wastewater purification.

[0003] Adsorption has become a commonly used method in water treatment due to its advantages such as simplicity and high efficiency. Currently, there are many adsorbents such as modified activated carbon, surfactant-modified zeolites, covalent organic frameworks (COFs), metal-organic frameworks (MOFs), and porous organic polymers (POPs). Inorganic materials such as activated carbon, zeolites, and mesoporous silica are cost-effective, but have poor removal performance and are difficult to reuse; emerging organic materials such as COFs and MOFs have better adsorption properties, but the synthesis process is demanding, the cost is high, and the production quantity is limited. Therefore, new adsorbents that are simply synthesized from inexpensive raw materials have ultra-fast removal rates, excellent adsorption capacity, and excellent recyclability, and have broad prospects in large-scale production.

[0004] Relatively speaking, porous organic polymers have become the best choice for the above-mentioned new adsorbents due to their high specific surface area, adjustable porosity, numerous adsorption sites and thermal stability. Porous organic polymers are connected by covalent bonds between organic parts and are usually constructed by building blocks and cross-linkers through appropriate cross-linking reactions. Due to the diversity of building blocks and cross-linkers, the functionality of monomers and the post-modification of persistent organic pollutants, it is more conducive to introducing functional groups into the skeleton to improve the driving force and removal rate. In recent years, in order to remove cationic pollutants, the common and prominent driving force is the electrostatic interaction force generated by the introduced negative ion groups. In addition, the driving force also includes hydrogen bonds, host-guest effects and π-π interactions. For example, Sessler et al. successfully synthesized calixpyrrole-based cross-linked POPs with ester as the end group, which were then hydrolyzed to form carboxylic acid anion groups for adsorbing cationic pollutants through electrostatic interactions. The target porous organic polymer can adsorb 90% of methyl blue within 10 minutes and reach equilibrium in 15 minutes, while the adsorption equilibrium time of paraquat exceeds 120 minutes; Lin et al. synthesized nitrogen-linked POPs, namely CTT-POP-1 containing multiple phenolic hydroxyl groups, which can ultra-fast adsorption of cationic dyes through hydrogen bonding and electrostatic interactions, and can completely adsorb methyl blue within 17 seconds, with a pseudo-secondary constant (k2) of 12.9gmg -1 min -1 However, further enhancing the adsorption kinetics so that it can reach adsorption equilibrium within 10 s or even shorter time and simultaneously achieve high removal efficiency (>99%) remains challenging. Summary of the Invention

[0005] The main technical problem solved by the present invention is to provide an anionic porous material, a preparation method and an application thereof.

[0006] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0007] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0008] Step 1: Pyrone and active methylene monomer are added to a reaction vessel, a reaction solvent is added, mixed evenly, and pyranonitrile intermediate 1 is obtained by Knoevenage condensation;

[0009] Step 2: adding the pyrancarbonitrile intermediate 1 obtained in step 1 and an aldehyde derivative into a reaction vessel, adding a reaction solvent, mixing evenly, and obtaining a pyrancarbonitrile monomer 2 through Knoevenage condensation;

[0010] Step 3: Add the pyranonitrile monomer 2 obtained in step 2 into a reaction vessel, add an oxidant, mix well, and then heat to react to obtain a porous material 1;

[0011] Step 4: Add the porous material 1 obtained in step 3 into a reaction container, add a sulfonation reagent, mix well and react to obtain the final pyranonitrile anion-based porous material.

[0012] Preferably, the active methylene monomer comprises at least one of the following structural formulas:

[0013]

[0014] Preferably, the aldehyde derivative comprises at least one of the following structural formulas:

[0015]

[0016] Furthermore, the molar ratio of pyrone to active methylene monomer in step 1 is 1:(1-3).

[0017] Preferably, the reaction solvent is any one or more of dimethyl sulfoxide, N,N-dimethylformamide, 1,4-dioxane, acetic anhydride, m-trimethylbenzene, o-dichlorobenzene, acetonitrile, chloroform, 1,2-dichloroethane or n-butanol.

[0018] Furthermore, the oxidant is ferric chloride or potassium permanganate.

[0019] Furthermore, the sulfonation reagent includes chlorosulfonic acid.

[0020] Furthermore, the heating reaction time is controlled to be: 24 to 72 hours

[0021] A pyranonitrile anion-based porous material is prepared by a preparation method of the pyranonitrile anion-based porous material.

[0022] A pyranonitrile anionic porous material is used for ultra-fast adsorption of pollutants in water.

[0023] The beneficial technical effects of the present invention are:

[0024] The series of novel anionic organic porous materials of the present invention have simple synthesis methods, ultrafast adsorption rates, high adsorption capacities and excellent reusability in removing organic dyes and pesticides, and have good application prospects and great application value in the field of water treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The solid of the anionic porous material in Example 1 13 C NMR spectrum.

[0026] Figure 2 This is the infrared spectrum of the anionic porous material in Example 2.

[0027] Figure 3 This is the thermogravimetric diagram of the anionic porous material in Example 3.

[0028] Figure 4 This is a scanning electron microscope image of the anionic porous material in Example 4.

[0029] Figure 5 3 is a nitrogen adsorption-desorption curve of the anionic porous material in Example 1.

[0030] Figure 6 This is a curve showing the relationship between the adsorption capacity of the anionic porous material obtained in Example 1 in Application Example 1 and the change in time of the adsorption capacity of Rhodamine B dye.

[0031] Figure 7 This is a curve showing the relationship between the adsorption capacity of the anionic porous material obtained in Example 2 of Application Example 2 and the change in time of the adsorption capacity of methylene blue dye.

[0032] Figure 8 This is a curve showing the relationship between the adsorption capacity of the anionic porous material obtained in Example 3 of Application Example 3 for paraquat pesticide and the change in the adsorption capacity over time.

[0033] Figure 9 This is a curve showing the relationship between the adsorption capacity of the anionic porous material obtained in Example 3 of Application Example 4 and the change in adsorption capacity of diquat pesticide over time. DETAILED DESCRIPTION

[0034] In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0035] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "front", "back", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0036] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "disposed" should be understood in a broad sense. For example, they may refer to fixed connection or disposition, detachable connection or disposition, or integral connection or disposition. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0037] Example 1

[0038] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0039] In a 100 mL round-bottom flask, 2,6-dimethyl-4H-pyran-4-one (1.0 g, 8 mmol) and malononitrile (1.0 g, 15 mmol) were dissolved in acetic anhydride (10 mL). The mixture was then heated to 160°C and refluxed for 2 hours. After the reaction was complete, the mixture was cooled to room temperature and added dropwise to 1 L of ice water with vigorous stirring. The mixture was then filtered to yield 1.35 g of a brown powder, Compound 1. Yield: 98.0%.

[0040] In a 250 mL three-necked flask, compound 1 (1.0 g, 5.8 mmol) and 4-(9H-carbazol-9-yl)benzaldehyde (3.7 g, 13.6 mmol) were dissolved in 30 mL of acetonitrile under a nitrogen atmosphere. The reaction was refluxed for 24 hours and monitored by TLC. After completion of the reaction, the mixture was filtered to obtain 3.49 g of compound 2 as a red powder. Yield: 85.3%.

[0041] Compound 2 (0.682 g, 1 mmol) and 20 mL of anhydrous dichloromethane were stirred in a 250 mL Shrek flask under a nitrogen atmosphere at room temperature. Potassium permanganate (0.8 g) was then added to the flask and the reactant was kept stirred at room temperature for 48 hours. After the reaction was complete, the crude product was filtered. Finally, 574 mg of a red product was obtained by Soxhlet extraction with THF.

[0042] The product (POP-TPA, 500 mg) and 20 mL of anhydrous dichloromethane were stirred in a 100 mL Shrek flask under a nitrogen atmosphere in an ice bath for 1 hour. 5 mL of chlorosulfonic acid was then added dropwise to the reaction mixture and stirred for 72 hours. Finally, the mixture was filtered, and the filter cake was washed several times with distilled water and then dried under vacuum at 60°C to yield 844 mg of dark brown product. Yield: 99.2%.

[0043] The synthetic route of POP-SO3H is as follows:

[0044]

[0045] The anionic porous material prepared according to the preparation method of the anionic porous material has a specific surface area of 145.5m 2 g -1 .

[0046] Example 2

[0047] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0048] Step 1: 2,6-dimethyl-4H-pyran-4-one (1.0 g, 8 mmol) and cyanoacetic acid (1.7 g, 20 mmol) were added to a reaction vessel, and a reaction solvent (dimethyl sulfoxide, 8 ml) was added. The mixture was mixed well and the pyrancarbonitrile intermediate 1 was obtained by Knoevenage condensation.

[0049] Step 2: The pyrancarbonitrile intermediate (1.0 g, 5.2 mmol) obtained in step 1 and 4-diphenylaminobenzaldehyde (3.0 g, 11 mmol) were added to a reaction vessel, and a reaction solvent (N,N-dimethylformamide, 20 ml) was added, mixed well, and pyrancarbonitrile monomer 2 was obtained by Knoevenage condensation;

[0050] Step 3: Add the pyranonitrile monomer 2 (1.0 g, 1.4 mmol) obtained in step 2 into a reaction vessel, add an oxidant (ferric chloride, 0.5 g), mix well, and then heat to react to obtain a porous material 1;

[0051] Step 4: The porous material 1 (1.0 g, 1.4 mmol) obtained in step 3 was added to a reaction vessel, and a sulfonation reagent (0.2 mL of chlorosulfonic acid) was added. After mixing evenly, the mixture was reacted to obtain the final pyranonitrile anion-based porous material;

[0052] Step 5: Using the pyranonitrile anion-based porous material obtained in step 4 to adsorb pollutants in water.

[0053] The anionic porous material prepared according to the preparation method of the anionic porous material has a specific surface area of 152.2m 2 g -1 .

[0054] Example 3

[0055] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0056] Step 1: 2,6-dimethyl-4H-pyran-4-one (1.0 g, 8 mmol) and cyanoacetic acid (1.7 g, 20 mmol) were added to a reaction vessel, and a reaction solvent (1,4-dioxane, 15 ml) was added. The mixture was mixed well and the pyranonitrile intermediate 1 was obtained by Knoevenage condensation.

[0057] Step 2: The pyrancarbonitrile intermediate (1.0 g, 5.2 mmol) obtained in step 1 and 4-(trityloxy)benzaldehyde (4.18 g, 12 mmol) were added to a reaction vessel, and a reaction solvent (m-trimethylbenzene, 50 ml) was added. The mixture was mixed well and the pyrancarbonitrile monomer 2 was obtained by Knoevenage condensation.

[0058] Step 3: Add the pyranonitrile monomer 2 (1.0 g, 1.2 mmol) obtained in step 2 into a reaction vessel, add an oxidant (ferric chloride, 2.0 g), mix well, and then heat to react to obtain a porous material 1;

[0059] Step 4: The porous material 1 (1.0 g, 1.2 mmol) obtained in step 3 was added to a reaction vessel, and a sulfonation reagent (0.2 mL of chlorosulfonic acid) was added. After mixing well, the mixture was reacted to obtain the final pyranonitrile anion-based porous material;

[0060] Step 5: Using the pyranonitrile anion-based porous material obtained in step 4 to adsorb pollutants in water.

[0061] The anionic porous material prepared according to the preparation method of the anionic porous material has a specific surface area of 138.4m 2 g -1 .

[0062] Example 4

[0063] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0064] Step 1: 2,6-dimethyl-4H-pyran-4-one (1.0 g, 8 mmol) and methyl cyanoacetate (1.48 g, 15 mmol) were added to a reaction vessel, and a reaction solvent (o-dichlorobenzene, 10 ml) was added. The mixture was mixed well and the pyrancarbonitrile intermediate 1 was obtained by Knoevenage condensation.

[0065] Step 2: The pyrancarbonitrile intermediate (1.0 g, 4.8 mmol) obtained in step 1 and 4-(1,2,2-triphenylethylene)benzaldehyde (5.4 g, 15 mmol) were added to a reaction vessel, and a reaction solvent (chloroform, 30 ml) was added. The mixture was mixed well and subjected to Knoevenage condensation to obtain pyrancarbonitrile monomer 2.

[0066] Step 3: Add the pyranonitrile monomer 2 (1.0 g, 1.1 mmol) obtained in step 2 into a reaction vessel, add an oxidant (potassium permanganate, 1.5 g), mix well, and then heat to react to obtain a porous material 1;

[0067] Step 4: The porous material 1 (0.5 g, 0.56 mmol) obtained in step 3 was added to a reaction vessel, and a sulfonation reagent (0.2 mL of chlorosulfonic acid) was added. After mixing well, the mixture was reacted to obtain the final pyranonitrile anionic porous material.

[0068] Step 5: Using the pyranonitrile anion-based porous material obtained in step 4 to adsorb pollutants in water.

[0069] The anionic porous material prepared according to the preparation method of the anionic porous material has a specific surface area of 146.3m 2 g -1 .

[0070] Example 5

[0071] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0072] Step 1: 2,6-dimethyl-4H-pyran-4-one (1.0 g, 8 mmol) and propyl cyanoacetate (1.7 g, 15 mmol) were added to a reaction vessel, and a reaction solvent (1,2-dichloroethane, 10 ml) was added. The mixture was mixed well and the pyranonitrile intermediate 1 was obtained by Knoevenage condensation.

[0073] Step 2: The pyrancarbonitrile intermediate (1.0 g, 4.5 mmol) obtained in step 1 and 4-(1,2,2-triphenylethylene)benzaldehyde (5.4 g, 15 mmol) were added to a reaction vessel, and a reaction solvent (n-butanol, 40 ml) was added. The mixture was mixed well and the pyrancarbonitrile monomer 2 was obtained by Knoevenage condensation.

[0074] Step 3: Add the pyranonitrile monomer 2 (1.0 g, 1.1 mmol) obtained in step 2 into a reaction vessel, add an oxidant (potassium permanganate, 2.0 g), mix well, and then heat to react to obtain a porous material 1;

[0075] Step 4: The porous material 1 (0.5 g, 0.56 mmol) obtained in step 3 was added to a reaction vessel, and a sulfonation reagent (0.2 mL of chlorosulfonic acid) was added. After mixing well, the mixture was reacted to obtain the final pyranonitrile anionic porous material.

[0076] Step 5: Using the pyranonitrile anion-based porous material obtained in step 4 to adsorb pollutants in water.

[0077] Example 6

[0078] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0079] Step 1: 2,6-dimethyl-4H-pyran-4-one (1.0 g, 8 mmol) and propyl cyanoacetate (1.7 g, 15 mmol) were added to a reaction vessel, and a reaction solvent (acetic anhydride, 15 ml) was added. The mixture was mixed well and the pyrancarbonitrile intermediate 1 was obtained by Knoevenage condensation.

[0080] Step 2: The pyrancarbonitrile intermediate (1.0 g, 4.5 mmol) obtained in step 1 and 4-(triphenylsilyl)phenylboronic acid (4.0 g, 11 mmol) were added to a reaction vessel, and a reaction solvent (acetic anhydride, 30 ml) was added. The mixture was mixed well and subjected to Knoevenage condensation to obtain pyrancarbonitrile monomer 2.

[0081] Step 3: Add the pyranonitrile monomer 2 (1.0 g, 1.1 mmol) obtained in step 2 into a reaction vessel, add an oxidant (potassium permanganate, 1.0 g), mix well, and then heat to react to obtain a porous material 1;

[0082] Step 4: The porous material 1 (0.5 g, 0.56 mmol) obtained in step 3 was added to a reaction vessel, and a sulfonation reagent (0.2 mL of chlorosulfonic acid) was added. After mixing well, the mixture was reacted to obtain the final pyranonitrile anionic porous material.

[0083] Step 5: Using the pyranonitrile anion-based porous material obtained in step 4 to adsorb pollutants in water.

[0084] Example 7

[0085] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0086] Step 1: 2,6-dimethyl-4H-pyran-4-one (1.0 g, 8 mmol) and cyanoacetic acid (1.7 g, 20 mmol) were added to a reaction vessel, and a reaction solvent (acetonitrile, 15 ml) was added. The mixture was mixed well and the pyrancarbonitrile intermediate 1 was obtained by Knoevenage condensation.

[0087] Step 2: The pyrancarbonitrile intermediate (1.0 g, 5.2 mmol) obtained in step 1 and 4-(9H-carbazol-9-yl)benzaldehyde (4.1 g, 15 mmol) were added to a reaction vessel, and a reaction solvent (acetonitrile, 50 ml) was added. The mixture was mixed well and subjected to Knoevenage condensation to obtain pyrancarbonitrile monomer 2.

[0088] Step 3: Add the pyranonitrile monomer 2 (1.0 g, 1.5 mmol) obtained in step 2 into a reaction vessel, add an oxidant (potassium permanganate, 2.0 g), mix well, and then heat to react to obtain a porous material 1;

[0089] Step 4: The porous material 1 (0.5 g, 0.8 mmol) obtained in step 3 was added to a reaction vessel, and a sulfonation reagent (0.2 mL of chlorosulfonic acid) was added. After mixing evenly, the mixture was reacted to obtain the final pyranonitrile anion-based porous material;

[0090] Step 5: Using the pyranonitrile anion-based porous material obtained in step 4 to adsorb pollutants in water.

[0091] Example 8

[0092] A method for preparing a pyranonitrile anionic porous material comprises the following steps:

[0093] Step 1: 2,6-dimethyl-4H-pyran-4-one (1.0 g, 8 mmol) and cyanoacetic acid (1.7 g, 20 mmol) were added to a reaction vessel, and a reaction solvent (acetic anhydride, 8 ml) was added. The mixture was mixed well and the pyrancarbonitrile intermediate 1 was obtained by Knoevenage condensation.

[0094] Step 2: The pyrancarbonitrile intermediate (1.0 g, 5.2 mmol) obtained in step 1 and 4-(triphenylsilyl)phenylboronic acid (4.0 g, 11 mmol) were added to a reaction vessel, and a reaction solvent (acetonitrile, 25 ml) was added. The mixture was mixed well and subjected to Knoevenage condensation to obtain pyrancarbonitrile monomer 2.

[0095] Step 3: Add the pyranonitrile monomer 2 (1.0 g, 1.1 mmol) obtained in step 2 into a reaction vessel, add an oxidant (ferric chloride, 1.0 g), mix well, and then heat to react to obtain a porous material 1;

[0096] Step 4: The porous material 1 (0.5 g, 0.56 mmol) obtained in step 3 was added to a reaction vessel, and a sulfonation reagent (0.2 mL of chlorosulfonic acid) was added. After mixing well, the mixture was reacted to obtain the final pyranonitrile anionic porous material.

[0097] Step 5: Using the pyranonitrile anion-based porous material obtained in step 4 to adsorb pollutants in water.

[0098] Application Example 1

[0099] Rhodamine B dye adsorption experiment:

[0100] The anionic porous material obtained in Example 1 was used to study the adsorption of Rhodamine B;

[0101] Test sample: anionic porous material obtained in Example 1;

[0102] Preparation of Rhodamine B dye solution: Prepare a Rhodamine B dye solution with an initial concentration (C0) of 50 ppm;

[0103] Test method: 40 mg of the anionic porous material (POP-SO3H) obtained in Example 1 was dispersed in 20 mL of distilled water and pre-ultrasonicated for 2 minutes. The material was then transferred to a flask and stirred at 800 rpm and 25°C. 20 mL of a 50 ppm rhodamine B dye solution was poured into the flask, and 3 mL of the mixture was withdrawn at regular intervals using a syringe. The mixture was then immediately passed through a 0.22 μm syringe filter, and the concentration of the filtrate was measured using a UV-visible spectrometer. The adsorption capacity at different adsorption times was calculated to obtain the rhodamine B dye adsorption capacity of the anionic porous material obtained by the present invention.

[0104] Figure 6 This is a graph showing the adsorption capacity of Rhodamine B dye over time for the anionic porous material obtained in Example 1. After only 5 seconds of contact with POP-SO₃H₃, the removal efficiency reached 96.9%, then increased to 99.4% within 30 seconds, nearly reaching adsorption equilibrium. At t = 10 minutes, the final RhB removal efficiency reached 99.9%, nearly achieving complete adsorption.

[0105] Application Example 2

[0106] Methylene blue dye adsorption experiment:

[0107] The anionic porous material obtained in Example 1 was subjected to a methylene blue adsorption study;

[0108] Test sample: anionic porous material obtained in Example 1;

[0109] Preparation of methylene blue dye solution: Prepare a methylene blue dye solution with an initial concentration (C0) of 50 ppm;

[0110] Test method: 40 mg of the anionic porous material (POP-SO3H) obtained in Example 1 was dispersed in 20 mL of distilled water and pre-ultrasonicated for 2 minutes. The material was then transferred to a flask and stirred at 800 rpm and 25°C. 20 mL of a methylene blue dye solution (50 ppm) was poured into the flask, and 3 mL of the mixture was withdrawn at regular intervals using a syringe. The mixture was then immediately passed through a 0.22 μm syringe filter, and the concentration of the filtrate was measured using a UV-visible spectrometer. The adsorption capacity at different adsorption times was calculated to obtain the methylene blue dye adsorption capacity of the anionic porous material obtained by the present invention.

[0111] Figure 7This is a graph showing the adsorption capacity of methylene blue dye over time for the anionic porous material obtained in Example 2 of Application Example 2. After only 5 seconds of contact with POP-SO3H, the removal efficiency reached 97.1%, then increased to 99.2% within 30 seconds, nearly reaching adsorption equilibrium. At t = 10 minutes, the final MB removal efficiency reached 99.8%, nearly achieving complete adsorption.

[0112] Application Example 3

[0113] Paraquat pesticide adsorption experiment:

[0114] The anionic porous material obtained in Example 3 was used to study the adsorption of paraquat;

[0115] Test sample: anionic porous material obtained in Example 3;

[0116] Preparation of paraquat pesticide solution: Prepare a paraquat pesticide solution with an initial concentration (C0) of 50 ppm;

[0117] Test method: 40 mg of the anionic porous material (POP-SO3H) obtained in Example 3 was dispersed in 20 mL of distilled water and pre-ultrasonicated for 2 minutes. The material was then transferred to a flask and stirred at 800 rpm and 25°C. 20 mL of a 50 ppm paraquat pesticide solution was poured into the flask, and 3 mL of the mixture was withdrawn at regular intervals using a syringe. The mixture was then immediately passed through a 0.22 μm syringe filter, and the concentration of the filtrate was measured using a UV-visible spectrometer. The adsorption capacity at different adsorption times was calculated to determine the paraquat adsorption capacity of the anionic porous material obtained by the present invention.

[0118] Figure 8 This is a graph showing the adsorption capacity of paraquat over time using the anionic porous material obtained in Example 3. When the contact time was only 10 seconds, the removal efficiency reached 96.0%. When t = 10 minutes, the final removal efficiency of MB reached 96.4%, nearly complete adsorption.

[0119] Application Example 4

[0120] Diquat pesticide adsorption experiment:

[0121] The anionic porous material obtained in Example 4 was used to study the adsorption of diquat;

[0122] Test sample: anionic porous material obtained in Example 4;

[0123] Preparation of diquat pesticide solution: Prepare a diquat pesticide solution with an initial concentration (C0) of 50 ppm;

[0124] Experimental Method: 40 mg of the anionic porous material (POP-SO3H) obtained in Example 4 was dispersed in 20 mL of distilled water and pre-ultrasonicated for 2 minutes. The material was then transferred to a flask and stirred at 800 rpm and 25°C. 20 mL of a 50 ppm diquat solution was poured into the flask, and 3 mL of the mixture was removed at regular intervals using a syringe. The mixture was immediately passed through a 0.22 μm syringe filter, and the filtrate concentration was measured using a UV-visible spectrometer. The adsorption capacity of the anionic porous material obtained by the present invention for diquat was calculated at different adsorption times. When the contact time was only 10 seconds, the removal efficiency reached 99.3%, and when t = 10 minutes, the final MB removal efficiency reached 99.8%, indicating near-complete adsorption.

[0125] Figure 9 This is a curve showing the relationship between the adsorption capacity of the anionic porous material obtained in Example 3 of Application Example 4 and the change in adsorption capacity of diquat pesticide over time.

[0126] As shown in Examples 1-8 and Application Examples 1-4, the pyranonitrile anionic porous material prepared by the present invention through a Knoevenage condensation reaction of pyrone, active methylene monomer, and aldehyde derivatives exhibits ultrafast adsorption rates, high adsorption capacity, and excellent reusability for removing organic dyes and pesticides. It has promising application prospects and significant value in the field of water treatment, as shown in Tables 1 and 2.

[0127] Table 1

[0128]

[0129] Table 2

[0130]

[0131] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a pyranonitrile anionic porous material, characterized in that: The following steps are involved: Step 1: Pyrone and active methylene monomer are added to a reaction vessel, a reaction solvent is added, mixed evenly, and pyranonitrile intermediate 1 is obtained by Knoevenage condensation; Step 2: adding the pyrancarbonitrile intermediate 1 obtained in step 1 and an aldehyde derivative into a reaction vessel, adding a reaction solvent, mixing evenly, and obtaining a pyrancarbonitrile monomer 2 through Knoevenage condensation; Step 3: Add the pyranonitrile monomer 2 obtained in step 2 into a reaction vessel, add an oxidant, mix well, and then heat to react to obtain a porous material 1; Step 4: adding the porous material 1 obtained in step 3 into a reaction container, adding a sulfonation reagent, mixing well and reacting to obtain the final pyranonitrile anion-based porous material; The active methylene monomer includes at least one of the following structural formulas: The aldehyde derivatives include at least one of the following structural formulas: The molar ratio of pyrone to active methylene monomer in step 1 is 1:(1-3); The molar ratio of the pyranonitrile intermediate 1 to the aldehyde derivative in the step 2 is 1:(2-4).

2. The method for preparing a pyranonitrile anionic porous material according to claim 1, wherein: The reaction solvent is any one or more of dimethyl sulfoxide, N,N-dimethylformamide, 1,4-dioxane, acetic anhydride, m-trimethylbenzene, o-dichlorobenzene, acetonitrile, chloroform, 1,2-dichloroethane or n-butanol.

3. The method for preparing the pyranonitrile anionic porous material according to claim 1, wherein: The oxidant is ferric chloride or potassium permanganate.

4. The method for preparing the pyranonitrile anionic porous material according to claim 1, wherein: The sulfonating agent includes chlorosulfonic acid.

5. The method for preparing the pyranonitrile anionic porous material according to claim 1, wherein: The heating reaction time is controlled to be: 24 to 72 hours.

6. A pyrancarbonitrile anion-based porous material prepared by the method for preparing a pyrancarbonitrile anion-based porous material according to any one of claims 1 to 5.

7. An application of the pyranonitrile anionic porous material as claimed in claim 6 for ultra-fast adsorption of pollutants in water.

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