A method for template-free preparation of self-supporting cationic organic two-dimensional materials in liquid phase

Abstract

This invention discloses a template-free method for preparing self-supporting cationic organic two-dimensional materials in the liquid phase. It utilizes the interaction between the different dimensions (crystal planes) of the crystal or aggregate structure of small organic monomers and the reaction system to separate anisotropy. By selecting the organic acid solution and aldehyde monomer, the reaction of reactant organic molecules is controlled to achieve simultaneous separation and reaction within the inherent crystal or aggregate structure. This transforms the process from constructing cationic organic two-dimensional clusters or aggregates based on specific dimensions of the molecular structure in the initial molecular state (raw material state) to the planar expansion or growth of cationic two-dimensional clusters or aggregates.

Description

Technical Field

[0001] This invention relates to the fields of advanced nanomaterial manufacturing and papermaking process chemicals, specifically to a method for template-free preparation of self-supporting cationic organic two-dimensional materials in a liquid phase. Background Technology

[0002] Organic two-dimensional materials are thin organic layers with molecular-scale thickness. With their molecular-level thickness, unique surface properties, special molecular structure, and diverse functional attributes, they show disruptive potential in fields such as energy, catalysis, separation, and barrier. General preparation methods for organic two-dimensional materials can be divided into two categories: bottom-up and top-down. Bottom-up methods directly generate two-dimensional materials through small-molecule organic chemical reactions under interfacial interactions or template assistance, such as chemical vapor deposition and two-phase interfacial reaction methods. Top-down methods utilize highly crystalline layered materials and obtain two-dimensional materials through soft chemical exfoliation or soft physical exfoliation methods. However, the controllable synthesis of organic two-dimensional materials still faces many scientific challenges: traditional bottom-up synthesis methods heavily rely on the spatial confinement effect of the two-phase interface (such as the gas / liquid interface) when preparing organic two-dimensional structures; the growth process is limited by the interfacial space and requires sophisticated instruments and equipment, while also requiring strict control of interfacial tension; template methods need to overcome the technical barriers to efficient separation of organic two-dimensional materials from the template. The implementation of top-down synthesis methods requires layered organic crystals with excellent crystallinity and easy exfoliation as a foundation. Currently, only some two-dimensional organic framework materials (such as COFs and MOFs) meet the exfoliation requirements. Moreover, these framework crystals have extremely strict requirements on the molecular symmetry of the basic structural units. Only specific systems with strong in-plane bonding or those that have undergone ionization treatment have the possibility of exfoliation, making it difficult to directly prepare self-supporting two-dimensional organic materials in the liquid phase without a template. Patent CN114539547A describes a method for preparing self-supporting organic nanosheets. This method mixes an imine-based covalent organic framework, a monofunctional competitive monomer, and an organic solvent, and carries out molecular exchange under ultrasonic conditions to obtain covalent organic framework nanoparticles. However, this preparation process takes up to a week and involves high reaction temperatures, which greatly limits its application areas. Furthermore, while this covalent organic framework (COF) can be exfoliated to form two-dimensional sheet materials, it is still limited by the preparation method and material properties. Patent CN118894973B presents a method for preparing two-dimensional β-ketoenamine COF nanosheets. This method mainly uses water as a solvent to prepare an aqueous solution of aliphatic amine (intercalating agent) and uses it as an exfoliation solution to exfoliate bulk COF materials under ultrasonic assistance, thus achieving the preparation of nanosheets in an aqueous phase. However, this method is still limited by the specific COF structure and is difficult to use as a general method for preparing self-supporting two-dimensional organic materials. Summary of the Invention

[0003] To address the limitations of existing organic two-dimensional material preparation technologies, such as restricted monomer molecular structures, high equipment requirements, reliance on interfaces or re-exfoliation operations, and difficulty in achieving template-free direct synthesis in the liquid phase, this invention aims to provide a template-free method for preparing self-supporting cationic organic two-dimensional materials in the liquid phase. This invention abandons the traditional approach of dissolving organic molecules into small molecules before reaction. Instead, it utilizes the different interactions between the initial state structure of organic molecules and their various dimensions with the solvent to achieve controllable separation during the reaction process. This transforms the process from constructing organic two-dimensional material clusters or aggregates based on specific dimensions of the initial aggregated structure of raw material molecules to the planar aggregation and growth of two-dimensional clusters. It overcomes the enormous entropy cost of two-dimensional molecular aggregation and the stringent requirements for selective aggregation in specific directions, resulting in a self-supporting cationic organic two-dimensional material with high positive charge density and a nanosheet-like structure.

[0004] To achieve the above objectives, the present invention adopts the following technical solution.

[0005] This invention provides a method for template-free preparation of self-supporting cationic organic two-dimensional materials in a liquid phase, comprising the following steps:

[0006] (1) Take polycrystalline or single-crystal powder of amino monomer, add it to organic acid solution, and let it stand for 1-12 hours; (2) Take the aldehyde monomer and add it to the solution after standing. Reflux and stir the reaction at 20℃-90℃ for 1h-72h to obtain a monodisperse self-supporting cationic organic two-dimensional material in the solution. (3) The monodisperse cationic organic two-dimensional material in solution is purified to obtain a stable dispersion of highly crystalline self-supporting cationic organic two-dimensional material.

[0007] Preferably, in step (1), the grain size of the amino monomer crystal powder is greater than 0.5 μm.

[0008] Preferably, in step (1), the solid content of the amino monomer is 1-10%, and the amino monomer is selected from single crystal or polycrystalline powder of organic molecules with multiple hydrogen bond donor and acceptor groups and a conjugated structure, including adenine, guanine, 2,6-diaminopurine, thymine and other bases or base derivatives.

[0009] Preferably, in step (1), the concentration of the organic acid solution is 0.1M~5M; the organic acid is a small molecule acid that has catalytic effect on the reaction of amine monomers and aldehyde monomers, including acetic acid, formic acid, and p-toluenesulfonic acid; the solvent is a solvent that is difficult to dissolve in amine monomers or aggregates under the reaction temperature conditions, including methanol, ethanol, propanol, dichloromethane, etc.

[0010] Preferably, the amino monomer in step (1) is in a non-dissolved state in the organic acid solution at the temperature of the reflux stirring reaction in step (2).

[0011] Preferably, in step (2), the aldehyde monomer is selected from short-chain or branched dialdehydes and polyaldehydes that are soluble in organic acid solutions, including glutaraldehyde, octyl dialdehyde, and nonadialdehyde.

[0012] Preferably, in step (2), the molar ratio of aldehyde monomer to amino monomer is 1:5 to 5:1.

[0013] Preferably, in step (2), the stirring speed is 20 rpm to 200 rpm.

[0014] Preferably, in step (3), the purification process is as follows: first, static sedimentation is performed, followed by dialysis or percolation; wherein the static sedimentation time is 12h~48h; for dialysis, a dialysis bag of 1 kDa~15 kDa is selected; for percolation, an ultrafiltration membrane of MWCO 5-100 kDa is used, with a pressure of 1-5 bar, cross-flow filtration, and the solid content is kept <5%.

[0015] Preferably, in step (3), the stable dispersion of the highly crystalline self-supporting cationic organic two-dimensional material has a high charge density of 1.8 mC / g to 12.3 mC / g.

[0016] The present invention also provides a self-supporting cationic organic two-dimensional material prepared by the above method, which is a nanosheet cationic polyelectrolyte material with a nanosheet structure and high charge characteristics, with a thickness of 1-10 nm and a planar size of 0.5 μm to 50 μm.

[0017] This invention also provides applications of the above-mentioned self-supporting cationic organic two-dimensional materials as flocculants, adsorbents, and carriers.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) This invention completely abandons the conventional mode of first dissolving organic molecules into smaller molecules before carrying out the reaction. This traditional dissolution reaction mode has many limitations and drawbacks, and it is difficult to achieve certain specific goals and effects in practical applications.

[0019] (2) This invention offers a novel approach, namely, a controllable process of reaction and separation based on the initial crystalline or aggregated structure of organic molecules (raw material state). Specifically, it involves a heterogeneous Schiff base reaction between polycrystalline or single-crystal powders of amino monomers (such as 2,6-diaminopurine) in a non-dissolved state within a polar dispersed phase and soluble aldehyde monomers (such as glutaraldehyde). Starting from the initial structure of a certain dimension in the raw material, this method employs a "structure-to-structure" approach to prepare organic two-dimensional materials. Through this unique and controllable process, this invention successfully achieves a significant transformation from constructing organic cationic two-dimensional clusters based on the molecular arrangement structure of a specific dimension in the initial aggregated structure of the raw material to the planar aggregation and growth of cationic two-dimensional clusters. Previous methods for constructing organic two-dimensional materials based on specific molecular structures faced numerous difficulties and challenges in achieving the planar aggregation and growth of cationic two-dimensional clusters. The novel method employed in this invention cleverly resolves these difficulties, achieving a highly efficient transformation of the reaction process.

[0020] (3) At the same time, the method provided by the present invention also overcomes the huge entropy cost that is inevitably borne in the two-dimensional molecular aggregation process. In the traditional two-dimensional molecular aggregation method, the huge entropy cost will seriously affect the reaction efficiency and the quality of the final product.

[0021] (4) Furthermore, traditional methods have extremely stringent requirements for the selectivity of aggregation in a specific direction, which greatly limits the flexibility and diversity of material preparation. The method provided by this invention does not depend on the interface, is simple to operate, and is green and low-carbon, thus solving these problems well and making the reaction process more stable and efficient. It further broadens the range of selectable reactive monomers from a mechanistic perspective, providing a new solution for their large-scale preparation and application.

[0022] (5) The self-supporting cationic organic two-dimensional material prepared by this invention is a polyelectrolyte material with high positive charge density, excellent dimensional stability, dispersion stability, and a nanosheet structure. Due to its unique high positive charge density and nanosheet structure, this polyelectrolyte material has broad application prospects and potential value in many fields. Attached Figure Description

[0023] Figure 1 The images show the AFM diagram (left) and dispersion diagram (right) of the cationic organic two-dimensional material synthesized by the Schiff base reaction in Example 1.

[0024] Figure 2 High-resolution TEM and SAED images of 2,6-diaminopurine crystals treated with organic acid solutions in Examples 1 and 2.

[0025] Figure 3 High-resolution TEM and SAED images of the self-supporting cationic organic two-dimensional material prepared in Example 3 are shown.

[0026] Figure 4 The images show the XRD patterns of the self-supporting cationic organic two-dimensional materials prepared in Examples 1 and 2. Detailed Implementation

[0027] The present invention will be further described below with reference to embodiments. It should be noted that the implementation of the present invention is not limited thereto.

[0028] Example 1 A template-free preparation method for self-supported cationic organic two-dimensional materials based on 2,6-diaminopurine in the liquid phase is described below: (1) Weigh out polycrystalline or single-crystal powder of 2,6-diaminopurine according to the standard of 2% (w / w) solid content. After weighing, add the weighed polycrystalline or single-crystal powder of 2,6-diaminopurine to an ethanol solution of 0.5M acetic acid. After the addition is completed, place the solution in a stable environment and let it stand for 12 hours.

[0029] (2) Weigh out a glutaraldehyde solution with a water content of 50% (w / w) according to a 1:1 molar ratio with 2,6-diaminopurine. Then, slowly and evenly add it to the solution obtained in step (1). Subsequently, place the mixed solution in a reaction flask, set the reaction temperature to 80°C, and carry out a reflux stirring reaction at this temperature with a stirring speed of 100 rpm for 12 h to obtain a monodisperse self-supporting cationic organic two-dimensional material in solution.

[0030] (3) Purification of the monodisperse self-supporting cationic organic two-dimensional material in solution. First, the sample was allowed to settle at room temperature for 12 hours. Then, the sample was further purified using a 15 kDa dialysis bag and dialyzed with anhydrous ethanol for 72 hours. After a series of purification operations, a stable dispersion of the highly crystalline self-supporting cationic organic two-dimensional material was finally obtained, which exhibited good stability and uniformity. The charge density was measured to be 5.7 mC / g using a colloidal charge titrator (PCD).

[0031] Figure 1 The AFM diagram (left) and dispersion diagram (right) of the cationic organic two-dimensional material synthesized by Schiff base reaction in Example 1 are shown. It can be seen from the figure that the thickness of the self-supporting cationic organic two-dimensional material prepared in Example 1 is 1-10 nm, and the planar size reaches 0.5 μm~50 μm.

[0032] Example 2 A template-free preparation method for self-supported cationic organic two-dimensional materials based on 2,6-diaminopurine in the liquid phase is described below: (1) Weigh out polycrystalline or single-crystal powder of 2,6-diaminopurine according to the standard of 2% (w / w) solid content. After weighing, add the weighed polycrystalline or single-crystal powder of 2,6-diaminopurine to an ethanol solution of 1M acetic acid. After the addition is completed, place the solution in a stable environment and let it stand for 6 hours.

[0033] (2) Weigh out a glutaraldehyde solution with a water content of 50% (w / w) according to a molar ratio of 2:1 with 2,6-diaminopurine. Then, slowly and evenly add it to the solution obtained in step (1). Subsequently, place the mixed solution in a reaction flask, set the reaction temperature to 90°C, and carry out a reflux stirring reaction at this temperature with a stirring speed of 50 rpm for 24 h to obtain a monodisperse self-supporting cationic organic two-dimensional material in solution.

[0034] (3) Purification of the monodisperse self-supporting cationic organic two-dimensional material in solution. First, the sample was allowed to settle at room temperature for 24 hours. Then, the sample was further purified using a 10 kDa dialysis bag and dialyzed with anhydrous ethanol for 72 hours. After a series of purification operations, a stable dispersion of the highly crystalline self-supporting cationic organic two-dimensional material was finally obtained, which exhibited good stability and uniformity. The charge density was measured to be 3.9 mC / g using a colloidal charge titrator (PCD).

[0035] Figure 2 High-resolution TEM and SAED images of the solvent-treated crystals of 2,6-diaminopurine in Examples 1 and 2 are shown. In Examples 1 and 2, under the treatment with acid solutions of the corresponding concentrations, the amino monomer raw materials still exist in a polycrystalline form, maintaining the stable and ordered arrangement of amino molecules during the reaction.

[0036] Figure 4 The XRD patterns of the self-supporting cationic organic two-dimensional materials prepared in Examples 1 and 2 are shown. The two-dimensional monolayer distribution structure exhibits a peak distribution; however, with higher glutaraldehyde additions, sharp peaks appear in the products, indicating the presence of more non-two-dimensional crystal structures. This may be because the addition of more glutaraldehyde increases the degree of fragmentation of the polycrystalline amino monomers, resulting in many small-molecule amino monomers reacting with glutaraldehyde to form aggregates different from the products.

[0037] Example 3 A template-free preparation method for self-supported cationic organic two-dimensional materials based on 2,6-diaminopurine in the liquid phase is described below: (1) Weigh out polycrystalline or single-crystal powder of 2,6-diaminopurine according to the standard of 2% (w / w) solid content. After weighing, add the weighed polycrystalline or single-crystal powder of 2,6-diaminopurine to an ethanol solution of 0.5M acetic acid. After the addition is completed, place the solution in a stable environment and let it stand for 12 hours.

[0038] (2) Weigh out a glutaraldehyde solution with a water content of 50% (w / w) according to a molar ratio of 1.5:1 with 2,6-diaminopurine. Then, slowly and evenly add it to the solution obtained in step (1). Subsequently, place the mixed solution in a reaction flask, set the reaction temperature to 80°C, and carry out a reflux stirring reaction at this temperature with a stirring speed of 50 rpm for 24 h to obtain a monodisperse self-supporting cationic organic two-dimensional material in solution.

[0039] (3) Purification of the monodisperse self-supporting cationic organic two-dimensional material in solution. First, the sample was allowed to settle at room temperature for 48 hours. Then, the sample was further purified using a 1 kDa dialysis bag and dialyzed with anhydrous ethanol for 72 hours. After a series of purification operations, a stable dispersion of the highly crystalline self-supporting cationic organic two-dimensional material was finally obtained, which exhibited good stability and uniformity. The charge density was measured to be 11.2 mC / g using a colloidal charge titrator (PCD).

[0040] Figure 3 High-resolution TEM and SAED images of the self-supporting cationic organic two-dimensional material prepared in Example 3 are shown. The high-resolution TEM image shows clear lattice fringes, and the electron diffraction pattern shows clear single-crystal diffraction spots, fully demonstrating the high crystallinity of this cationic organic two-dimensional material. Furthermore, the lattice corresponding to its fringes and diffraction spots is consistent with... Figure 2 The positions of the diffraction encapsulation in the XRD patterns of Examples 1 and 2 shown correspond to the basic characteristics of randomly distributed aggregates of highly crystalline nanosheets.

[0041] Example 4 The method for preparing self-supported cationic organic two-dimensional materials based on adenine in a template-free liquid phase comprises the following steps: (1) Weigh out polycrystalline or single-crystal powder of adenine according to the standard of 1% (w / w) solid content. After weighing, add the weighed polycrystalline or single-crystal powder of adenine to an ethanol solution with a concentration of 0.1M acetic acid. After the addition is completed, place the solution in a stable environment and let it stand for 6 hours.

[0042] (2) Weigh out a nonadialdehyde solution with a water content of 50% (w / w) according to a molar ratio of 5:1 with adenine. After weighing out the glutaraldehyde solution with a water content of 50%, slowly and evenly add it to the solution obtained in step (1). Then, place the mixed solution in a reaction flask, set the reaction temperature to 80°C, and carry out the reflux stirring reaction at this temperature. The stirring speed is 50 rpm, and the reaction lasts for 48 hours to obtain a monodisperse self-supporting cationic organic two-dimensional material in solution.

[0043] (3) Purification of the monodisperse self-supporting cationic organic two-dimensional material in solution. First, the sample was allowed to settle at room temperature for 12 hours. Then, percolation was performed using an ultrafiltration membrane (MWCO 50 kDa) at a pressure of 3 bar, with cross-flow filtration to maintain a solid content of <5%. After a series of purification operations, a stable dispersion of the highly crystalline self-supporting cationic organic two-dimensional material was finally obtained, which exhibited good stability and uniformity. The charge density was measured to be 7.8 mC / g using a colloidal charge titrator (PCD).

[0044] Example 5 A template-free method for preparing self-supporting cationic organic two-dimensional materials based on 8-acerguanine in the liquid phase is described below: (1) Weigh out polycrystalline or single-crystal powder of 8-acerguanine according to the standard of 10% (w / w) solid content. After weighing, add the weighed polycrystalline or single-crystal powder of 8-acerguanine to an ethanol solution of 5M acetic acid. After the addition is completed, place the solution in a stable environment and let it stand for 1 hour.

[0045] (2) Weigh out a 50% (w / w) octanedialdehyde solution at a molar ratio of 1:5 with 8-acerguanine. After weighing out the 50% glutaraldehyde solution, slowly and evenly add it to the solution obtained in step (1). Then, place the mixed solution in a reaction flask, set the reaction temperature to 20°C, and carry out a reflux stirring reaction at this temperature. The stirring speed is 20 rpm, and the reaction lasts for 72 h to obtain a monodisperse self-supporting cationic organic two-dimensional material in solution.

[0046] (3) Purification of the monodisperse self-supporting cationic organic two-dimensional material in solution. First, the sample was allowed to settle at room temperature for 24 hours. Then, percolation was performed using an ultrafiltration membrane (MWCO 100 kDa) at a pressure of 5 bar, with cross-flow filtration to maintain a solid content of <5%. After a series of purification operations, a stable dispersion of the highly crystalline self-supporting cationic organic two-dimensional material was finally obtained, which exhibited good stability and uniformity. The charge density was measured to be 12.3 mC / g using a colloidal charge titrator (PCD).

[0047] Example 6 A template-free preparation method for self-supported cationic organic two-dimensional materials based on 5-aminouracil in the liquid phase is described below: (1) Weigh out polycrystalline or single-crystal powder of 5-aminouracil according to the standard of 5% (w / w) solid content. After weighing, add the weighed polycrystalline or single-crystal powder of 5-aminouracil to an ethanol solution of 3M acetic acid. After the addition is completed, place the solution in a stable environment and let it stand for 12 hours.

[0048] (2) Weigh out a glutaraldehyde solution with a water content of 50% (w / w) according to a 1:1 molar ratio with 5-aminouracil. After weighing out the glutaraldehyde solution with a water content of 50%, slowly and evenly add it to the solution obtained in step (1). Then, place the mixed solution in a reaction flask, set the reaction temperature to 80°C, and carry out a reflux stirring reaction at this temperature. The stirring speed is 200 rpm, and the reaction lasts for 1 hour to obtain a monodisperse self-supporting cationic organic two-dimensional material in the solution.

[0049] (3) Purification of the monodisperse self-supporting cationic organic two-dimensional material in solution. First, the sample was allowed to settle at room temperature for 48 hours. Then, percolation was performed using an ultrafiltration membrane (MWCO 1 kDa) at a pressure of 1 bar, with cross-flow filtration to maintain a solid content of <5%. After a series of purification operations, a stable dispersion of the highly crystalline self-supporting cationic organic two-dimensional material was finally obtained, which exhibited good stability and uniformity. The charge density was measured to be 1.8 mC / g using a colloidal charge titrator (PCD).

[0050] The above description represents preferred embodiments of the present invention and is not intended to limit the invention. Those skilled in the art will recognize that the present invention can be modified and varied in various ways. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for template-free preparation of self-supporting cationic organic two-dimensional materials in a liquid phase, characterized in that, Includes the following steps: (1) Take polycrystalline or single-crystal powder of amino monomer, add it to organic acid solution, and let it stand for 1-12 hours; (2) Take the aldehyde monomer and add it to the solution after standing. Reflux and stir the reaction at 20℃-90℃ for 1h-72h to obtain a monodisperse self-supporting cationic organic two-dimensional material in the solution. (3) The monodisperse cationic organic two-dimensional material in solution is purified to obtain a stable dispersion of highly crystalline self-supporting cationic organic two-dimensional material.

2. The method for preparing self-supporting cationic organic two-dimensional materials in a liquid phase without a template, as described in claim 1, is characterized in that... In step (1), the solid content of the amino monomer is 1-10% by mass. The amino monomer is selected from single crystal or polycrystalline powder of organic molecules with multiple hydrogen bond donor and acceptor groups and a conjugated structure, including adenine, guanine, 2,6-diaminopurine, thymine and other bases or base derivatives.

3. The method for preparing self-supporting cationic organic two-dimensional materials in a liquid phase without a template, as described in claim 1, is characterized in that... In step (1), the concentration of the organic acid solution is 0.1M~5M; the organic acid is a small molecule acid that has catalytic activity in the reaction of amine monomers and aldehyde monomers, including formic acid, acetic acid, and p-toluenesulfonic acid; the solvent is a solvent that is difficult to dissolve in amine monomers or aggregates under the reaction temperature conditions, including methanol, ethanol, propanol, and dichloromethane.

4. The method for preparing self-supporting cationic organic two-dimensional materials in a liquid phase without a template, as described in claim 1, is characterized in that... The amino monomer in step (1) is in an undissolved state in the organic acid solution at the temperature of the reflux and stirring reaction in step (2).

5. The method for preparing self-supporting cationic organic two-dimensional materials in a liquid phase without a template, as described in claim 1, is characterized in that... In step (2), the aldehyde monomer is selected from short-chain or branched dialdehydes and polyaldehydes that are soluble in organic acid solutions, including glutaraldehyde, octaldehyde, and nonadialdehyde.

6. The method for preparing self-supporting cationic organic two-dimensional materials in a liquid phase without a template, as described in claim 1, is characterized in that... In step (2), the molar ratio of the aldehyde monomer to the amino monomer is 1:5 to 5:

1.

7. The method for preparing self-supporting cationic organic two-dimensional materials in a liquid phase without a template, as described in claim 1, is characterized in that... In step (2), the stirring speed is 20 rpm to 200 rpm; In step (3), the purification process is as follows: first, static sedimentation is performed, followed by dialysis or percolation; wherein the static sedimentation time is 12h~48h; for dialysis, a dialysis bag of 1 kDa~15 kDa is selected; for percolation, an ultrafiltration membrane of MWCO 5-100 kDa is used, and cross-flow filtration is performed at a pressure of 1-5 bar to keep the solid content always <5%.

8. The method for preparing self-supporting cationic organic two-dimensional materials in a liquid phase without a template, as described in claim 1, is characterized in that... In step (3), the stable dispersion of the highly crystalline self-supporting cationic organic two-dimensional material has a high charge density of 1.8 mC / g to 12.3 mC / g.

9. A self-supporting cationic organic two-dimensional material prepared by the method for template-free preparation of self-supporting cationic organic two-dimensional materials in a liquid phase according to any one of claims 1-8, characterized in that, The self-supporting cationic organic two-dimensional material is a nanosheet cationic polyelectrolyte material with a nanosheet structure and high charge characteristics, with a thickness of 1-10 nm and a planar size of 0.5 μm to 50 μm.

10. The application of the two-dimensional supporting cationic material as a flocculant, adsorbent, or carrier as described in claim 9.

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