Silver ion organic adsorbent, and preparation method and application thereof

Abstract

The application relates to a silver ion organic adsorbent and a preparation method and application thereof, and belongs to the technical field of composite materials. The silver ion organic adsorbent BPD-POP is generated by the reaction of 4,4-bipyridine and pyrrole, dimethoxymethane, and the structural formula is as follows: the silver ion organic adsorbent can be used for efficiently and selectively adsorbing silver ions from a solution, and has strong recycling and regeneration capacity.

Description

Technical Field

[0001] This invention relates to a silver ion organic adsorbent, its preparation method and application, belonging to the field of composite material technology. Background Technology

[0002] There are various methods for removing metal ions from aqueous solutions, such as membrane separation, electrochemical methods, chemical precipitation, and adsorption. Adsorption is considered the most effective method due to its simplicity and lack of secondary pollution. Currently, a variety of adsorbents have been developed for adsorbing silver ions, including biochar, diatomaceous earth, graphene oxide, and covalent organic frameworks. To improve adsorption efficiency, functional groups such as thiols, rhodanine, mercaptoacetic acid, and trimercaptotriazine have been introduced; however, the introduction of these functional groups usually requires complex synthetic processes.

[0003] Porous organic polymers, with their large surface area, have shown great potential in the field of adsorption. Their high porosity, large surface area, and stable physicochemical properties make them suitable for metal ion adsorption. Porous organic polymers with specific functional groups can enhance their adsorption capacity and selectivity for various metals.

[0004] Existing silver ion adsorbents still lack sufficient adsorption capacity for high concentrations of silver ions. While introducing specific functional groups has improved adsorption efficiency, the synthesis conditions are stringent and the process complex. Furthermore, inefficient binding mechanisms and poor optimization of functional groups within the adsorbent structure lead to low adsorption capacity and selectivity. Many silver ion adsorbents face difficulties in regeneration and reuse due to chemical or structural degradation during the regeneration process, and repeated use often results in a significant decrease in adsorption efficiency. By addressing these challenges through innovative design and enhanced material stability, silver ion adsorbents can be further optimized for wider application in water treatment and other fields. Summary of the Invention

[0005] To address the problems of poor selectivity and difficulty in recycling existing silver ion adsorbents, this invention proposes a silver ion organic adsorbent, its preparation method, and its application. This silver ion organic adsorbent, BPD-POP, is generated by reacting 4,4-bipyridine with pyrrole and dimethoxymethane. The silver ion organic adsorbent can be used to efficiently and selectively adsorb silver ions from solution and has a strong recycling capacity.

[0006] An organic silver ion adsorbent, wherein the adsorbent is generated by reacting 4,4-bipyridine with pyrrole and dimethoxymethane, is designated as adsorbent BPD-POP, and its structural formula is as follows:

[0007]

[0008] The specific steps for preparing the silver ion organic adsorbent are as follows:

[0009] (1) Pyrrole and dimethoxymethane were dissolved in N,N-dimethylformamide solvent by stirring to obtain solution A;

[0010] (2) Dissolve 4,4-bipyridine in solution A by stirring to obtain solution B;

[0011] (3) Add anhydrous FeCl3 to solution B and stir the reaction at 30-50℃ for 1-3 hours to obtain solution C;

[0012] (4) Place solution C in a high-pressure reactor and react at 90–110°C for 45–55 h. After cooling to room temperature, separate the solid and liquid phases. Soak the solid in ethanol for 6–24 h, then wash it successively with ethanol and deionized water, and vacuum dry to obtain the silver ion organic adsorbent BPD-POP. The chemical reaction formula is:

[0013]

[0014] Preferably, in step (1), the volume ratio of pyrrole to dimethoxymethane is 1:2.1 to 2.4, and the concentration of pyrrole in solution A is 0.1 to 0.3 mol / L.

[0015] Preferably, the solid-liquid ratio (g:mL) of 4,4-bipyridine in step (2) to pyrrole in step (1) is 1:0.3 to 1.5.

[0016] Preferably, the solid-liquid ratio (g:mL) of anhydrous FeCl3 in step (3) to pyrrole in step (1) is 1:0.3 to 0.8.

[0017] The silver ion organic adsorbent can be used to efficiently and selectively adsorb silver ions from solution.

[0018] The method for recycling the silver ion organic adsorbent is as follows: a desorption solution mixture consisting of 1% concentrated hydrochloric acid and 10% thiourea is used as the desorbent, and the adsorbent is recycled by washing after desorption.

[0019] The principle of selective adsorption of silver ions by the organic adsorbent BPD-POP of this invention is as follows: The organic adsorbent BPD-POP has a large specific surface area and a rigid structure; it has N-containing functional groups including -NH, -C=N, and -CN; its large pore size and specific surface area give it a strong adsorption capacity, and a large number of N-containing functional groups can chelate with Ag(I), selectively adsorbing Ag(I) in the solution.

[0020] The beneficial effects of this invention are:

[0021] (1) The silver ion organic adsorbent of the present invention has surface electrostatic effect and N-functional group, which can efficiently and selectively adsorb silver ions in solution and has strong recycling and regeneration ability.

[0022] (2) The preparation method of the silver ion organic adsorbent of the present invention is simple, flexible and low cost. Attached Figure Description

[0023] Figure 1 Here is a SEM image of the silver ion organic adsorbent from Example 1;

[0024] Figure 2 EDS diagram of silver ion organic adsorbent in Example 1;

[0025] Figure 3 The BET diagram for the silver ion organic adsorbent in Example 1 is shown below.

[0026] Figure 4 The image shows the XRD patterns of the silver ion organic adsorbent before and after adsorption of silver ions in Example 1.

[0027] Figure 5 The image shows the FT-IR spectrum of the silver ion organic adsorbent in Example 1.

[0028] Figure 6 The images are FT-IR images of the silver ion organic adsorbents after recycling and regeneration in Examples 1, 2, and 3. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0030] Example 1: A method for preparing a silver ion organic adsorbent, the specific steps of which are as follows:

[0031] (1) Pyrrole and dimethoxymethane were dissolved in N,N-dimethylformamide solvent by stirring to obtain solution A; the volume ratio of pyrrole to dimethoxymethane was 1:2.2, and the concentration of pyrrole in solution A was 0.2 mol / L;

[0032] (2) Dissolve 4,4-bipyridine in solution A by stirring to obtain solution B; the 4,4-bipyridine is reacted with the solution in step (1).

[0033] The solid-liquid ratio of pyrrole (g:mL) is 1:1.3;

[0034] (3) Add anhydrous FeCl3 to solution B and stir the reaction at 35℃ for 2 hours to obtain solution C; the solid-liquid ratio of the anhydrous FeCl3 to the pyrrole in step (1) is 1:0.4 g:mL.

[0035] (4) Solution C was placed in a high-pressure reactor and reacted at 100℃ for 48 hours. After cooling to room temperature, the solid and liquid were separated. The solid was soaked in ethanol for 15 hours, then washed with ethanol and deionized water in sequence, and vacuum dried to obtain the silver ion organic adsorbent BPD-POP. The chemical reaction formula is as follows:

[0036]

[0037] The SEM, EDS, BET, XRD, FT-IR, and FT-IR results of the silver ion organic adsorbent BPD-POP in this embodiment are shown in the figure. Figure 1-6 As shown in the figure, the silver ion organic adsorbent BPD-POP is mainly composed of elements C and N, with weight percentages of 62.77% and 37.23% respectively. The XRD pattern indicates that BPD-POP has low crystallinity, consistent with the amorphous nature of polymers. The FT-IR pattern shows that at 1388 cm⁻¹... -1 1348cm -1 and 1085cm -1 Characteristic peaks belonging to -C=N and -CN appeared; 3500cm -1 The vibrational peak of the nearby -NH further confirms the successful synthesis of the silver ion organic adsorbent BPD-POP; after cyclic regeneration, the structure of the organic adsorbent remains unchanged and its properties are stable.

[0038] This embodiment measures the selective adsorption performance of the silver ion organic adsorbent BPD-POP for silver ions:

[0039] At room temperature, BPD-POP (10 mg) and the adsorption solution (pH = 1, 10 mL) were added to a 15 mL centrifuge tube. The adsorption solution contained Ag(I) 163.92 mg / L, Ca(II) 187.16 mg / L, Ni(II) 164.81 mg / L, Co(II) 159.82 mg / L, Al(III) 150.35 mg / L, and Mg(II) 132.6 mg / L. The tube was shaken at 200 rpm for 20 h. The adsorbent was separated by centrifugation and the supernatant was obtained. The residual concentration of the remaining metal ions in the supernatant was determined by ICP-OES.

[0040] The removal rates of Ag(I) were calculated to be 99.38%, Ca(II) 3.33%, Ni(II) 13.05%, Co(II) 0.81%, Al(III) 4.44%, and Mg(II) 7.56%.

[0041] Therefore, it can be seen that the silver ion organic adsorbent BPD-POP in this embodiment has a strong selectivity for silver ions;

[0042] This embodiment measures the cyclic regeneration performance of the silver ion organic adsorbent BPD-POP:

[0043] After the adsorbent was eluted with a desorbent (a mixture of 1% concentrated hydrochloric acid and 10% thiourea desorption solution), it was centrifuged and then washed with distilled water until the solution was neutral, thus completing the regeneration of the adsorbent BPD-POP. After four repeatable experiments, the removal rate of Ag(I) in the fourth experiment was 77.41%.

[0044] Example 2: A method for preparing a silver ion organic adsorbent, the specific steps of which are as follows:

[0045] (1) Pyrrole and dimethoxymethane were stirred and dissolved in N,N-dimethylformamide solvent to obtain solution A; the volume ratio of pyrrole to dimethoxymethane was 1:2.3, and the concentration of pyrrole in solution A was 0.1 mol / L;

[0046] (2) Dissolve 4,4-bipyridine in solution A by stirring to obtain solution B; the 4,4-bipyridine is reacted with the solution in step (1).

[0047] The solid-liquid ratio of pyrrole (g:mL) is 1:0.9;

[0048] (3) Add anhydrous FeCl3 to solution B and stir the reaction at 40℃ for 1.5h to obtain solution C; the solid-liquid ratio of the anhydrous FeCl3 to the pyrrole in step (1) is 1:0.5 g:mL.

[0049] (4) Place solution C in a high-pressure reactor and react at 105℃ for 45h. After cooling to room temperature, separate the solid and liquid. Soak the solid in ethanol for 20h, then wash it with ethanol and deionized water in sequence, and vacuum dry to obtain silver ion organic adsorbent BPD-POP.

[0050] This embodiment measures the selective adsorption performance of the silver ion organic adsorbent BPD-POP for silver ions:

[0051] At room temperature, BPD-POP (10 mg) and the adsorption solution (pH = 1, 10 mL) were added to a 15 mL centrifuge tube. The adsorption solution contained Ag(I) 163.92 mg / L, Ca(II) 187.16 mg / L, Ni(II) 164.81 mg / L, Co(II) 159.82 mg / L, Al(III) 150.35 mg / L, and Mg(II) 132.6 mg / L. The tube was shaken at 200 rpm for 20 h. The adsorbent was separated by centrifugation and the supernatant was obtained. The residual concentration of the remaining metal ions in the supernatant was determined by ICP-OES.

[0052] The removal rates of Ag(I) were calculated to be 99.49%, Ca(II) 0.81%, Ni(II) 12.97%, Co(II) 1.16%, Al(III) 2.47%, and Mg(II) 9.01%.

[0053] Therefore, it can be seen that the silver ion organic adsorbent BPD-POP in this embodiment has a strong selectivity for silver ions;

[0054] This embodiment measures the cyclic regeneration performance of the silver ion organic adsorbent BPD-POP:

[0055] The adsorbent was eluted with a desorbent (a mixture of 1% concentrated hydrochloric acid and 10% thiourea) and then centrifuged, followed by washing with distilled water until the solution was neutral, thus completing the regeneration of the adsorbent BPD-POP. After four repeatable experiments, the removal rate of Ag(I) in the fourth experiment was 72.91%.

[0056] Example 3: A method for preparing a silver ion organic adsorbent, the specific steps of which are as follows:

[0057] (1) Pyrrole and dimethoxymethane were stirred and dissolved in N,N-dimethylformamide solvent to obtain solution A; the volume ratio of pyrrole and dimethoxymethane was 1:2.1, and the concentration of pyrrole in solution A was 0.3 mol / L;

[0058] (2) Dissolve 4,4-bipyridine in solution A by stirring to obtain solution B; the 4,4-bipyridine is reacted with the solution in step (1).

[0059] The solid-liquid ratio of pyrrole is 1:0.5 g:mL;

[0060] (3) Add anhydrous FeCl3 to solution B and stir the reaction at 30°C for 2.5 h to obtain solution C; the solid-liquid ratio of the anhydrous FeCl3 to the pyrrole in step (1) is 1:0.4 g:mL.

[0061] (4) Place solution C in a high-pressure reactor and react at 95°C for 52 hours. After cooling to room temperature, separate the solid and liquid. Soak the solid in ethanol for 10 hours, then wash it with ethanol and deionized water in sequence, and dry it under vacuum to obtain the silver ion organic adsorbent BPD-POP.

[0062] This embodiment measures the selective adsorption performance of the silver ion organic adsorbent BPD-POP for silver ions:

[0063] At room temperature, BPD-POP (10 mg) and the adsorption solution (pH = 1, 10 mL) were added to a 15 mL centrifuge tube. The adsorption solution contained Ag(I) 163.92 mg / L, Ca(II) 187.16 mg / L, Ni(II) 164.81 mg / L, Co(II) 159.82 mg / L, Al(III) 150.35 mg / L, and Mg(II) 132.6 mg / L. The tube was shaken at 200 rpm for 20 h. The adsorbent was separated by centrifugation and the supernatant was obtained. The residual concentration of the remaining metal ions in the supernatant was determined by ICP-OES.

[0064] The removal rates of Ag(I) were calculated to be 99.72%, Ca(II) 0.85%, Ni(II) 14.3%, Co(II) 2.86%, Al(III) 5.45%, and Mg(II) 11.73%.

[0065] Therefore, it can be seen that the silver ion organic adsorbent BPD-POP in this embodiment has a strong selectivity for silver ions;

[0066] This embodiment measures the cyclic regeneration performance of the silver ion organic adsorbent BPD-POP.

[0067] The adsorbent was eluted with a desorbent (a mixture of 1% concentrated hydrochloric acid and 10% thiourea) and then centrifuged, followed by washing with distilled water until the solution was neutral, thus completing the regeneration of the adsorbent BPD-POP. After four repeatable experiments, the removal rate of Ag(I) in the fourth experiment was 79.55%.

[0068] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A silver ion organic adsorbent, characterized in that: The adsorbent is generated by reacting 4,4-bipyridine with pyrrole and dimethoxymethane, and is designated as adsorbent BPD-POP. Its structural formula is as follows: 。 2. The method for preparing the silver ion organic adsorbent according to claim 1, characterized in that, The specific steps are as follows: (1) Pyrrole and dimethoxymethane were dissolved in N,N-dimethylformamide solvent by stirring to obtain solution A; (2) Dissolve 4,4-bipyridine in solution A by stirring to obtain solution B; (3) Add anhydrous FeCl3 to solution B and stir the reaction at 30~50℃ for 1~3h to obtain solution C; (4) Place solution C in a high-pressure reactor and react at 90~110℃ for 45~55h. After cooling to room temperature, separate the solid and liquid. Soak the solid in ethanol for 6~24h, then wash it with ethanol and deionized water in sequence, and dry it under vacuum to obtain the silver ion organic adsorbent.

3. The method for preparing the silver ion organic adsorbent according to claim 2, characterized in that: In step (1), the volume ratio of pyrrole to dimethoxymethane is 1:2.1~2.4, and the concentration of pyrrole in solution A is 0.1~0.3 mol / L.

4. The method for preparing the silver ion organic adsorbent according to claim 2, characterized in that: In step (2), the solid-liquid ratio of 4,4-bipyridine to pyrrole in step (1) is 1:0.3~1.5 g:mL.

5. The method for preparing the silver ion organic adsorbent according to claim 2, characterized in that: In step (3), the solid-liquid ratio of anhydrous FeCl3 to pyrrole in step (1) is 1:0.3~0.8 g:mL.

6. The application of the silver ion organic adsorbent according to claim 1 in the selective adsorption of silver ions in solution.

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