A two-dimensional covalent organic polymer and a preparation method and application thereof

Abstract

This invention relates to the field of heavy metal ion detection and environmental remediation technology, specifically to a two-dimensional covalent organic polymer, its preparation method, and its applications. This addresses the existing Hg... 2+ The existing detection methods suffer from insufficient sensitivity, complex operation, poor selectivity of adsorbent materials, and difficulty in simultaneously achieving identification and removal. The method of this invention involves placing 2,4-diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, 1,4-dioxane, mesitylene, and an aqueous solution of acetic acid in a high-pressure reactor. The raw materials are then ultrasonically dispersed to a uniform state. The reactor is then placed in an oven for static reaction. After the reaction, the reactor is cooled to room temperature, filtered, washed with acetone, and dried to obtain a two-dimensional organic polymer containing a benzothiazole structure. The two-dimensional covalent organic polymer prepared by this invention exhibits high sensitivity (36 nM) and a rapid response time (90 s) for the detection and adsorption of mercury ions in environmental water.

Description

Technical Field

[0001] This invention relates to the field of heavy metal ion detection and environmental remediation technology, specifically to a two-dimensional covalent organic polymer, its preparation method, and its application. Background Technology

[0002] Mercury ions (Hg) 2+ Hg is a highly toxic heavy metal pollutant that can accumulate in organisms through the food chain, posing a serious threat to life and health. Related medical research indicates that Hg... 2+ It can enter the human body through the skin, respiratory tract, and other routes. Its bioaccumulation in the body can cause a variety of neurological disorders and related diseases.

[0003] Mercury pollution has become increasingly prominent in daily life due to urbanization and industrialization. Accordingly, the World Health Organization (WHO) has clearly stipulated that the permissible limit for mercury in food is 0.001 mg / L. Therefore, achieving effective control of Hg in the environment is crucial. 2+ Effective monitoring and adsorption of [the substance] are of great significance, and developing materials that combine high-sensitivity detection and high-efficiency adsorption performance has become an important research direction.

[0004] Currently, commonly used methods for detecting and removing mercury ions in water include spectrophotometry, atomic absorption spectrometry, atomic fluorescence spectrometry, and inductively coupled plasma mass spectrometry. However, these methods have drawbacks such as expensive equipment and cumbersome operating procedures, making it difficult to achieve rapid on-site detection.

[0005] Despite significant progress in the field of mercury ion detection using fluorescent probe technology, existing methods still face challenges in terms of detection sensitivity, response speed, and ease of practical application.

[0006] For example, patent CN121471138A discloses a fluorescent probe for mercury ion detection based on quinoline, its preparation method, and its application. This patent involves adding m-aminophenol, tetrachlorobenzoquinone, and hydrochloric acid to an organic solvent. After dissolution, the temperature is raised to 105-110℃, and crotonaldehyde solution is added dropwise. The mixture is refluxed and stirred for 4-5 hours. After the reaction is complete, the mixture is cooled to room temperature, extracted, and dried to obtain a crude product. After purification, intermediate II is obtained. Intermediate II and phenyl thiochloroformate are dissolved in an organic solvent, and triethylamine is added. The mixture is stirred at room temperature for 10-12 hours. After the reaction is complete, the solvent is removed by vacuum distillation to obtain the crude product. This crude product is then purified to obtain the fluorescent probe. The probe molecule reacts with Hg²⁺ in solution. + The concentration exhibited a good linear relationship, with a detection limit of 41.25 μmol / L and a response time of 40 min. However, the detection limit of this probe is still in the micromolar range, which is insufficient for ultra-trace Hg. 2+Its rapid identification capability (such as nanomolar or even picomolar levels) is limited; at the same time, its response time is as long as 40 minutes, which is difficult to meet the needs of rapid response for sudden water pollution incidents or on-site real-time detection.

[0007] Covalent organic polymers (COPs), as a class of porous framework materials constructed from strong covalent bonds, exhibit unique advantages in the field of heavy metal pollution remediation due to their high specific surface area, controllable pore size, and abundant surface functional groups. Compared with traditional small-molecule fluorescent probes, COPs, through the synergistic effect of their ordered pore structure and multiple coordination sites, can simultaneously achieve highly sensitive fluorescence recognition and efficient adsorption and removal of heavy metal ions. These materials not only possess sensing characteristics such as rapid response, high selectivity, and low detection limits, but also exhibit excellent adsorption capacity and cycling stability, effectively overcoming the limitations of traditional probes in adsorption performance. Therefore, developing COPs materials with dual functionalities of fluorescence detection and adsorption provides a new material basis for constructing efficient and visualized heavy metal pollution treatment platforms.

[0008] Patent CN 116693821 B discloses an organic polymer for rapid detection and degradation of mercury ions, its preparation method, and its applications. The polymer's luminescence properties originate from its conjugated organic polymer backbone, while its mercury ion recognition function comes from the sulfur hydrocarbon chains embedded within the organic polymer backbone. This polymer exhibits high chemical and thermal stability, enabling repeated recycling. However, it suffers from several drawbacks: it cannot achieve simultaneous detection and adsorption, has a long detection time, and its detection level is limited to the micromolar level, making it unsuitable for ultra-trace Hg detection. 2+ Detection (e.g., nanomolar or even picomolar levels). Summary of the Invention

[0009] In view of this, the present invention addresses the problem of existing Hg... 2+ To address the problems of insufficient sensitivity, complex operation, poor selectivity of adsorbent materials, and difficulty in simultaneously achieving identification and removal in detection methods, this paper provides a novel two-dimensional covalent organic polymer, its preparation method, and its application. This polymer exhibits high selective recognition capability (high sensitivity) and efficient adsorption performance, while also being low in cost and easy to operate, making it a novel mercury ion identification and adsorption material and method.

[0010] To achieve the objectives of this invention, the technical solution adopted is as follows:

[0011] A two-dimensional covalent organic polymer has the following structural formula:

[0012]

[0013] The synthetic route for a two-dimensional covalent organic polymer is as follows:

[0014]

[0015] The steps of a method for preparing a two-dimensional covalent organic polymer are as follows:

[0016] Two-dimensional covalent organic polymers were prepared by placing 2,4-diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, a mixed solvent, and an aqueous solution of acetic acid in a high-pressure reactor and then dispersing the mixture by ultrasonication.

[0017] Further, the mixed solution is any one or more of N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, 1,4-dioxane, n-butanol, mesitylene, o-dichlorobenzene, and toluene.

[0018] Furthermore, the amount of 2,4-diamino-1,4-benzenedithiol dihydrochloride used was 0.28 mmol;

[0019] The amount of 1,3,5-tris(tetra-formylphenyl)benzene used was 0.19 mmol;

[0020] The volume of the mixed solvent is 2-5 mL;

[0021] The volume of the acetic acid aqueous solution used is 0.01-0.5 mL.

[0022] Furthermore, the reaction conditions are: ultrasonic dispersion for 10-30 minutes, and reaction at 30-150℃ for 2-5 days.

[0023] The two-dimensional covalent organic polymer prepared by the above method.

[0024] The two-dimensional covalent organic polymer prepared by the above method is used in the detection and adsorption of mercury ions in aqueous solution.

[0025] The procedure for detecting and adsorbing mercury ions in aqueous solution is as follows:

[0026] Step 1: Mix sodium dodecylbenzenesulfonate and polystyrene in a mass ratio of 1:2;

[0027] Step 2: Add the mixture obtained in Step 1 to a round-bottom flask containing DMF and stir at room temperature to form a mixture;

[0028] Step 3: Disperse the two-dimensional covalent organic polymer TB-COP uniformly in DMF, add it dropwise to the mixture obtained in Step 2, and stir until the mixture is homogeneous;

[0029] Step 4: Pour the solution obtained in Step 3 into a film-forming container and air dry to obtain a TB-COP film;

[0030] Step 5: Immerse the TB-COP film prepared in Step 4 in mercury ion solutions of different concentrations, dry it, and observe it under a UV lamp to verify its detection effect on mercury ions;

[0031] Step 6: Conduct mercury ion removal rate tests to determine pH=7 as the optimal condition for subsequent adsorption experiments;

[0032] Step 7: Under the selected optimized conditions, conduct adsorption experiments and measure the adsorption effect of the TB-COP film under different mercury ion concentrations.

[0033] Step 8: Determine the amount of mercury ions adsorbed by atomic absorption spectrometry, and calculate the maximum amount of mercury ions adsorbed by the material at room temperature.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] 1. The method of the present invention uses benzaldehyde and 2-aminothiophene as precursors to introduce a simple benzothiazole structure into a covalent organic polymer. Compared with ordinary small molecule fluorescent probes, it has the advantages of high sensitivity (36 nM) and fast response time (90s).

[0036] 2. The two-dimensional covalent organic polymer TB-COP prepared by the method of this invention has a two-dimensional layered structure that provides abundant active sites and mass transfer channels, which is beneficial for Hg. 2+ Rapid diffusion and coordination.

[0037] 3. The two-dimensional covalent organic polymer prepared by the method of the present invention for Hg 2+ It exhibits a highly selective fluorescence quenching response, enabling ultra-trace detection (nanomolar level). Furthermore, through the synergistic coordination of sulfur and nitrogen atoms, it achieves the detection of Hg. 2+ Highly efficient adsorption; detection and adsorption can be completed simultaneously.

[0038] 4. The material of this invention can complete the removal of Hg within 2 minutes at room temperature. 2+ Rapid identification and enrichment without the need for complex excitation conditions or large instruments, making it suitable for rapid on-site detection and emergency response.

[0039] 5. This invention can be applied to the detection and adsorption of mercury ions in environmental water bodies, realizing the first application of two-dimensional covalent organic polymers in the field of environmental science and engineering. Attached Figure Description

[0040] Figure 1 The images shown are the scanning electron microscope (SEM) image and the actual measured PXRD pattern of the COP material in Example 1.

[0041] Among them, (a) SEM image of TB-COP; (b) PXRD image of TB-COP.

[0042] Figure 2 This is the N2 adsorption-desorption curve of the COP material in Example 1;

[0043] Among them, (a) N2 adsorption-desorption curves of TB-COP (with pore size distribution diagram attached); (b) BET test curves of TB-COP.

[0044] Figure 3 The infrared spectrum and thermogravimetric spectrum of the COP material in Example 1 are shown below.

[0045] Among them, (a) FT-IR plot of TB-COP and its raw materials; (b) thermogravimetric plot of TB-COP.

[0046] Figure 4 TB-COP and TB-COP@Hg 2+ XPS plot of N elements.

[0047] Figure 5 The fluorescence excitation, emission, and ion selectivity spectra of the COP material in this invention are shown.

[0048] Among them, (a) is the fluorescence excitation and emission spectrum of TB-COP; (b) is the ion selectivity and competition histogram of TB-COP.

[0049] Figure 6 The fluorescence titration and linearity graphs of the COP material in this invention are shown.

[0050] Among them, (a) Hg of TB-COP 2+ (a) Titration curve; (b) Hg of TB-COP 2+ Linear relationship between concentration gradient and fluorescence intensity (0-40 μM).

[0051] Figure 7 TB-COP recognizes and adsorbs Hg 2+ Fluorescence lifetime diagrams before and after;

[0052] Among them, (a) fluorescence lifetime diagram of TB-COP; (b) TB-COP@Hg 2+ Fluorescence lifetime diagram.

[0053] Figure 8 The TB-COP in this invention affects Hg 2+ The recognition mechanism;

[0054] Among them, (a) the core part of TB-COP and Hg 2+ (a) HOMO-LUMO distribution and energy before and after coordination; (b) Simulated absorption and emission energy, wavelength, oscillator strength and orbital contribution rate of TB-COP. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0056] The structural formula of the two-dimensional covalent organic polymer TB-COP of this invention is as follows:

[0057]

[0058] The synthetic route for preparing the two-dimensional covalent organic polymer of this invention is as follows:

[0059]

[0060] Example 1:

[0061] A method for preparing a two-dimensional covalent organic polymer TB-COP is as follows:

[0062] 2,4-Diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, a mixed solvent of 1,4-dioxane / trimethylbenzene, and an aqueous solution of acetic acid were placed in a 25 mL high-pressure reactor and ultrasonically dispersed. Finally, the reactor was placed in an oven at 120 °C and allowed to stand for 3 days to prepare a two-dimensional organic polymer containing a benzothiazole structure.

[0063] The ratio of the aqueous solution of 2,4-diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, 1,4-dioxane, mesitylene, and acetic acid is 0.28 mmol: 0.19 mmol: 3.34 mL: 1.67 mL: 0.5 mL.

[0064] After the reaction was completed, the reactor was cooled to room temperature, filtered, washed three times with acetone, and dried for 8 hours to obtain the two-dimensional organic polymer TB-COP (122.4 mg), with a yield of approximately 85%.

[0065] The two-dimensional covalent organic polymer prepared in this invention is used for the detection and adsorption of mercury ions in aqueous solution. The specific method steps are as follows:

[0066] Step 1: Mix sodium dodecylbenzenesulfonate and polystyrene in a mass ratio of 1:2;

[0067] Step 2: Add the mixture obtained in Step 1 to a round-bottom flask containing DMF and stir at room temperature to form a mixture;

[0068] Step 3: Disperse the two-dimensional covalent organic polymer TB-COP uniformly in DMF, add it dropwise to the mixture obtained in Step 2, and stir until the mixture is homogeneous;

[0069] Step 4: Pour the solution obtained in Step 3 into a film-forming container and air dry to obtain a TB-COP film;

[0070] Step 5: Immerse the prepared TB-COP film in Hg of different concentrations. 2+ In the solution, after drying, observation under a 365 nm UV lamp revealed varying degrees of fluorescence quenching.

[0071] Step 6: Conduct mercury ion removal rate tests under different pH conditions to determine that pH=7 is the most suitable adsorption pH value for subsequent adsorption experiments.

[0072] Step 7: Place TB-COP in different concentrations of mercury ions and use an atomic absorption spectrometer to test the adsorption capacity. Obtain the fluorescence intensity changes by atomic absorption spectroscopy to obtain the adsorption kinetic curves. The curve results show that TB-COP adsorbs mercury ions at different concentrations of mercury ions. 2+ The adsorption capacity increased sharply within 3 hours, and then tended to reach equilibrium;

[0073] Step 8: Subsequently, simulations were performed using first-order and second-order kinetic models respectively, and the fitted linear correlation plots were obtained; the calculation results show that different Hg values... 2+ The kinetic curves for all concentrations belong to a second-order kinetic model. Correlation coefficients were obtained at different concentrations, and the Hg values ​​were calculated using linear curves. 2+ Adsorption capacity at different concentrations. Relevant parameters are shown in Table 1:

[0074] Table 1. Relevant parameters under two adsorption kinetic models

[0075]

[0076] Figure 1 The images show the scanning electron microscope (SEM) image and actual PXRD pattern of the COP material in Example 1. The morphology of the sample was observed using a thermal field emission scanning electron microscope, and the results are shown below. Figure 1 (a) SEM image of TB-COP. The synthesized COP material exhibits irregularly shaped spherical particles with a uniform distribution. Powder X-ray diffraction (PXRD) results are shown below. Figure 1 (b) The PXRD pattern of TB-COP confirms that there are no sharp crystallization peaks in TB-COP, indicating that it has an amorphous structure.

[0077] Figure 2 The N2 adsorption-desorption curve of the COP material in Example 1 is shown below. The sample was activated by degassing at 100°C for 10 hours, and the nitrogen adsorption-desorption isotherms of the COP structure were obtained by measuring gas adsorption from 0 to 1 atm at 77 K. The results are shown below. Figure 2 (a) N2 adsorption-desorption curves of TB-COP (with attached diagram showing pore size distribution). Figure 2 (b) BET test curve of TB-COP, Brunauer-Emmett-Teller (BET) calculated its specific surface area to be 58.0 m². 2 / g.

[0078] Figure 3 The infrared and thermogravimetric spectra of the COP material in Example 1 are shown below. The bonding of the COP structure was studied using Fourier transform infrared spectroscopy (FT-IR), and the results are shown in [Figure 1]. Figure 3 (a) FT-IR plots of TB-COP and its feedstock, with 2569 cm⁻¹ corresponding to -SH in feedstock DBD. -1 The peak disappears, and the C=O corresponding to TFPB is at 1689 cm⁻¹. -1 The disappearance of the chromatogram indicates the successful formation of the benzothiazole structure, signifying the successful preparation of the COP material. Thermogravimetric analysis was performed on the sample by heating it from room temperature to 1000℃ at a heating rate of 10℃ / min under an argon atmosphere. The results are shown in [Figure number missing]. Figure 3 (b) The thermogravimetric curve of TB-COP shows that its thermal decomposition temperature is 579℃, indicating that the synthesized COP material has good thermal stability.

[0079] Figure 4 The image shows the nitrogen element XPS spectrum of the COP material in this invention; the results of X-ray photoelectron spectroscopy (XPS) analysis of the COP structure are shown below. Figure 4 The thermogravimetric curve of TB-COP showed C=N bonds in the fine N 1s spectrum, indicating that the COP structure was successfully prepared.

[0080] Figure 5 The fluorescence excitation, emission, and ion selectivity spectra of the COP material in this invention are shown below. TB-COP was dispersed in acetonitrile solution, and its optimal excitation and emission peaks were determined. The results are shown in [Figure Number]. Figure 5 (a) Fluorescence excitation and emission spectra of TB-COP. The excitation and emission wavelengths of TB-COP are 340 nm and 402 nm, respectively. Ion recognition and ion competition experiments were performed, and the results are shown in [Figure 1]. Figure 5 (b) A histogram of ion selectivity and competition for TB-COP, revealing its ion selectivity for Hg. 2+ Ions have good recognition capabilities.

[0081] Figure 6 The fluorescence titration and linearity graphs of the COP material in this invention are shown; for example... Figure 6 (a) Hg of TB-COP 2+ (a) Titration curve; (b) Hg of TB-COP 2+ The linear relationship between concentration gradient and fluorescence intensity (0-40 μM) is shown in the fluorescence titration experiment. As Hg... 2+With stepwise titration, the fluorescence effect significantly decreased, and this decrease showed a good linear relationship in the range of 0 μM to 40 μM. R 2 =0.9993. In addition, COP material has a certain effect on Hg. 2+ The response is very rapid, reaching stability within 90 seconds.

[0082] To further understand the effect of TB-COP on Hg 2+ The identification function of TB-COP was used to calculate the limit of detection (LOD). Before calculating the LOD, 10 blank curve measurements were performed on the TB-COP / acetonitrile dispersion system, yielding a standard deviation σ = 249 (N = 10). The LOD was then calculated from the linear relationship curve as 3σ / S = 30 nM, indicating that TB-COP can effectively detect Hg in water. 2+ It exhibits high sensitivity. (Based on fluorescence lifetime fitting) Figure 7 (a) Fluorescence lifetime plot of TB-COP; (b) TB-COP@Hg 2+ The fluorescence lifetime plot shows that the fluorescence lifetime of the probe TB-COP is 0.74 ns. (TB-COP@Hg) 2+ Its fluorescence lifetime is 0.66 ns.

[0083] Figure 8 The TB-COP in this invention affects Hg 2+ The recognition mechanism; such as Figure 8 (a) TB-COP core components and Hg 2+ (a) HOMO-LUMO distribution and energy before and after coordination; (b) Simulated absorption and emission energies, wavelengths, oscillator strengths and orbital contribution rates of TB-COP. The specific recognition mechanism of TB-COP for Hg²⁺ is derived from the coordination of N and S atoms with Hg²⁺ in its structure. Coordination leads to a reduction in the HOMO-LUMO band gap and orbital distribution reconstruction, which together verify that the cooperative coordination of N and S atoms is the essential reason for fluorescence recognition and quenching.

[0084] Example 2

[0085] 2,4-Diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, N,N-dimethylacetamide:acetonitrile mixed solvent and acetic acid aqueous solution were placed in a 25 mL high-pressure reactor. The system was dispersed by sonication for 10 min. Finally, the reactor was placed in an oven at 70 °C and allowed to stand for 4 days to prepare a two-dimensional organic polymer containing a benzothiazole structure.

[0086] The ratio of the aqueous solution of 2,4-diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, N,N-dimethylacetamide, acetonitrile, and acetic acid is 0.28 mmol: 0.19 mmol: 3.34 mL: 1.67 mL: 0.5 mL.

[0087] After the reaction was completed, the product mixture was washed three times with acetone and dried in a vacuum oven for 8 hours to obtain the two-dimensional organic polymer material COP (105.2 mg), with a yield of 73%.

[0088] Example 3

[0089] A mixture of 2,4-diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, o-dichlorobenzene, toluene, and an aqueous solution of acetic acid was placed in a 25 mL high-pressure reactor. The system was dispersed by sonication for 20 min. Finally, the reactor was placed in an oven at 120 °C and allowed to stand for 3 days to obtain a two-dimensional organic polymer containing a benzothiazole structure.

[0090] The ratio of the aqueous solution of 2,4-diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, o-dichlorobenzene, toluene, and acetic acid is 0.28 mmol: 0.19 mmol: 2.5 mL: 2.5 mL: 0.5 mL.

[0091] After the reaction was completed, the product mixture was washed three times with acetone and dried in a vacuum oven for 8 hours to obtain a two-dimensional organic polymer material (115.6 mg), with a yield of 80%.

[0092] The above-described embodiment 1 is the preferred embodiment of the present invention.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A two-dimensional covalent organic polymer, characterized in that, The structural formula is:

2. The method for preparing a two-dimensional covalent organic polymer according to claim 1, characterized in that, The synthetic route is as follows:

3. The method for preparing a two-dimensional covalent organic polymer according to claim 2, characterized in that, The steps are as follows: Two-dimensional covalent organic polymers were prepared by placing 2,4-diamino-1,4-benzenedithiol dihydrochloride, 1,3,5-tris(tetra-formylphenyl)benzene, a mixed solvent, and an aqueous solution of acetic acid in a high-pressure reactor and then dispersing the mixture by ultrasonication.

4. The method for preparing a two-dimensional covalent organic polymer according to claim 3, characterized in that, The mixed solution is any one or more of N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, 1,4-dioxane, n-butanol, mesitylene, o-dichlorobenzene, and toluene.

5. The method for preparing a two-dimensional covalent organic polymer according to claim 3, characterized in that, The amount of 2,4-diamino-1,4-benzenedithiol dihydrochloride used is 0.28 mmol; The amount of 1,3,5-tris(tetra-formylphenyl)benzene used was 0.19 mmol; The volume of the mixed solvent is 2-5 mL; The volume of the acetic acid aqueous solution used is 0.01-0.5 mL.

6. The method for preparing a two-dimensional covalent organic polymer according to claim 3, characterized in that, The reaction conditions are: ultrasonic dispersion for 10-30 minutes, and reaction at 30-150℃ for 2-5 days.

7. The two-dimensional covalent organic polymer prepared by the method according to claim 3.

8. The application of the two-dimensional covalent organic polymer prepared according to claim 7 in the detection and adsorption of mercury ions in aqueous solution.

9. The application according to claim 8, characterized in that, The procedure for detecting and adsorbing mercury ions in aqueous solution is as follows: Step 1: Mix sodium dodecylbenzenesulfonate and polystyrene in a mass ratio of 1:2; Step 2: Add the mixture obtained in Step 1 to a round-bottom flask containing DMF and stir at room temperature to form a mixture; Step 3: Disperse the two-dimensional covalent organic polymer TB-COP uniformly in DMF, add it dropwise to the mixture obtained in Step 2, and stir until the mixture is homogeneous; Step 4: Pour the solution obtained in Step 3 into a film-forming container and air dry to obtain a TB-COP film; Step 5: Immerse the TB-COP film prepared in Step 4 in mercury ion solutions of different concentrations, dry it, and observe it under a UV lamp to verify its detection effect on mercury ions; Step 6: Conduct mercury ion removal rate tests to determine pH=7 as the optimal condition for subsequent adsorption experiments; Step 7: Under the selected optimized conditions, conduct adsorption experiments and measure the adsorption effect of the TB-COP film under different mercury ion concentrations. Step 8: Determine the amount of mercury ions adsorbed by atomic absorption spectrometry, and calculate the maximum amount of mercury ions adsorbed by the material at room temperature.

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