A multi-hydroxyl pyrrole network adsorption material, a preparation method and application thereof

Abstract

This invention relates to a multi-hydroxypyrrole network adsorbent material, its preparation method, and its applications, belonging to the field of composite material technology. The multi-hydroxypyrrole network adsorbent material, denoted as XTAPR, is synthesized by heating and reflux using (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal, pyrrole, and terephthalaldehyde as ligand raw materials. Its structural formula is [structural formula missing]. This multi-hydroxypyrrole network adsorbent material possesses a high density of hydroxyl sites, enabling efficient and selective adsorption of gallium ions, and exhibits good reusability.

Description

Technical Field

[0001] This invention relates to a multi-hydroxypyrrole network adsorbent material, its preparation method and application, belonging to the field of composite material technology. Background Technology

[0002] Currently, the main methods for gallium extraction both domestically and internationally include chemical precipitation, solvent extraction, ion exchange, and adsorption. Among these, adsorption is of high application value in gallium recovery due to its relatively short process flow, mild operating conditions, and suitability for treating gallium-containing solutions with medium to low concentrations.

[0003] Existing adsorption methods typically employ ion exchange resins or other functional adsorbent materials, achieving gallium adsorption, separation, and enrichment through the interaction between the material's surface functional groups and gallium ions. However, these adsorbent materials still have some shortcomings in practical applications. For example, they exhibit low selectivity for gallium ions and are easily affected by coexisting impurity ions such as aluminum, iron, and vanadium, thus impacting the gallium adsorption and separation efficiency. Furthermore, existing adsorbent materials have limited adsorption capacity, making it difficult to meet the requirements for efficient gallium enrichment. Some adsorbent materials also suffer from insufficient chemical stability and poor recyclability, especially during repeated adsorption-desorption cycles, where adsorption performance deteriorates and materials become deactivated. Therefore, there is still a need to develop an adsorbent material with high selectivity, large adsorption capacity, good chemical stability, and superior recyclability to overcome the shortcomings of current industrial production methods, such as unsatisfactory gallium separation and recovery in complex systems, susceptibility to impurity interference, and short material cycle life. Summary of the Invention

[0004] To address the problems of insufficient selectivity for gallium, limited adsorption capacity, and poor recyclability of existing adsorbent materials in gallium separation and recovery, this invention proposes a multi-hydroxypyrrole network adsorbent material, its preparation method, and its application. The adsorbent XTAPR, i.e., the multi-hydroxypyrrole network adsorbent material, is prepared by reacting (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal, pyrrole, and terephthalaldehyde as raw materials. The multi-hydroxypyrrole network adsorbent material has a high density of hydroxyl sites, enabling effective adsorption and enrichment of gallium ions, and exhibits good reusability.

[0005] A polyhydroxypyrrole network adsorbent material, denoted as XTAPR, is synthesized by heating and reflux using (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal, pyrrole, and terephthalaldehyde as ligand raw materials. The structural formula is as follows: .

[0006] The preparation method of the polyhydroxypyrrole network adsorbent material includes the following specific steps: (1) Dissolve (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal in hydrochloric acid solution to obtain (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution; (2) The (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution was heated to 50-70℃, and pyrrole and terephthalaldehyde were added sequentially and mixed evenly to obtain a mixed solution. The mixed solution was refluxed at 50-70℃ for 67-77 h, cooled to room temperature, and the solid and liquid were separated. The solid was washed with deionized water until neutral and dried to obtain the multi-hydroxypyrrole network adsorbent material XTAPR. The synthesis steps are as follows: .

[0007] Preferably, the mass concentration of the hydrochloric acid solution in step (1) is 7~10%, and the concentration of (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal is 0.15~0.25mol / L.

[0008] Preferably, the concentration of pyrrole in the mixed solution in step (2) is 0.15~0.25mol / L, and the concentration of terephthalaldehyde is 0.15~0.25mol / L.

[0009] Application of the polyhydroxypyrrole network adsorbent material in the selective capture of gallium ions in solution.

[0010] Application of the multi-hydroxypyrrole network adsorbent material XTAPR in the selective adsorption of Ga(III) in alkaline complex solutions.

[0011] The mechanism of efficient gallium ion adsorption by multi-hydroxyl pyrrole network adsorbent material (XTAPR): The adsorbent material XTAPR introduces abundant hydroxyl groups and nitrogen-containing sites, providing a multi-site binding environment for gallium ion adsorption. The oxygen and nitrogen sites in XTAPR jointly participate in the capture of gallium ions during adsorption, and interact with gallium ions through electrostatic and coordination interactions. The partition coefficient of XTAPR for gallium ions is 1.04 L / g, significantly higher than that for other metal ions, indicating that XTAPR exhibits strong selective adsorption capacity for Ga(III). Effective desorption of adsorbed gallium can be achieved using a combined solution of thiourea and hydrochloric acid. XTAPR maintains a high adsorption rate even after multiple adsorption-desorption cycles, demonstrating excellent reusability.

[0012] The beneficial effects of this invention are: (1) The multi-hydroxy pyrrole network adsorbent material of the present invention contains abundant hydroxyl groups and nitrogen-containing active sites, which can enhance the binding ability of gallium ions through electrostatic interaction and coordination interaction, and exhibit good selective adsorption performance. (2) The preparation method of the polyhydroxypyrrole network adsorbent material of the present invention is relatively simple, the obtained material is easy to separate, has good recycling performance, and is suitable for the separation and recovery of gallium ions. Attached Figure Description

[0013] Figure 1 This is a SEM image of the multihydroxypyrrole network adsorbent material from Example 1; Figure 2 EDS diagram of the multihydroxypyrrole network adsorbent material in Example 1; Figure 3 The image shows the FT-IR spectrum of the polyhydroxypyrrole network adsorbent material in Example 1. Figure 4 The effect of coexisting ions on the multihydroxypyrrole network adsorbent material prepared in Example 1; Figure 5 This is a SEM image of gallium ions adsorbed by the multi-hydroxypyrrole network adsorbent material in Example 1. Figure 6 The image shows the XPS image of gallium ions after adsorbing by the multi-hydroxypyrrole network adsorbent material in Example 1. Detailed Implementation

[0014] 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.

[0015] The multi-hydroxypyrrole network adsorbent material of this invention, synthesized by heating and reflux using (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal, pyrrole, and terephthalaldehyde as ligand raw materials, is designated XTAPR and has the following structural formula: ; The multi-hydroxy pyrrole network adsorbent material contains abundant hydroxyl groups and nitrogen-containing sites, providing a multi-site binding environment for gallium ion adsorption.

[0016] Example 1: A method for preparing a multi-hydroxypyrrole network adsorbent material, the specific steps of which are as follows: (1) Dissolve (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal in an 8% hydrochloric acid solution to obtain a (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution with a concentration of 0.2 mol / L. (2) The (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution was heated to 60°C, and pyrrole and terephthalaldehyde were added sequentially and mixed evenly to obtain a mixed solution. The mixed solution was refluxed at 60°C for 72 h, cooled to room temperature, and the solid and liquid were separated. The solid was washed with deionized water until neutral and dried to obtain the multi-hydroxypyrrole network adsorbent material XTAPR. The concentration of pyrrole in the mixed solution was 0.2 mol / L, and the concentration of terephthalaldehyde was 0.2 mol / L. The synthesis steps are as follows: ; SEM, EDS, and FT-IR images of the multihydroxypyrrole network adsorbent material in this embodiment are shown below. Figures 1-3 As shown in the figure, the polyhydroxypyrrole network adsorbent material is mainly composed of C, N, and O elements, with mass percentages of 80.23%, 9.59%, and 10.18%, respectively. In the FT-IR spectrum, at 3422.4 cm⁻¹... -1 A broad absorption band appears nearby, attributed to the superposition of the stretching vibrations of -OH and NH; 1168.4 cm⁻¹ -1 The peak at 1048.5 cm⁻¹ is related to the vibration of the pyrrole ring skeleton. -1 A CO stretching vibration peak appeared at 879.4 cm⁻¹. -1 The peak corresponds to the out-of-plane =CH deformation vibration of the pyrrole ring; the above characteristic peaks together indicate that the framework structure and functional groups of XTAPR have been successfully constructed, among which -OH, NH and other groups can serve as potential sites for Ga(III) adsorption. Determination of the selective adsorption performance of the polyhydroxypyrrole network adsorbent XTAPR for Ga(III): At room temperature, XTAPR (40 mg) and the adsorption solution (pH=9, 40 mL) were added to a 50 mL centrifuge tube. The adsorption solution contained 66.70 mg / L Ga(III), 57.32 mg / L Ca(II), 66.40 mg / L V(V), and 54.20 mg / L As(V). The tube was shaken at 230 rpm for 24 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. The effect of coexisting ions on the adsorption of gallium ions by the multi-hydroxypyrrole network adsorbent material prepared in this embodiment is shown in the figure. Figure 4 The removal rates of Ga(III) were calculated to be 50.96%, Ca(II) 11.81%, V(V) 5.59%, and As(V) 13.12%. This shows that the multi-hydroxypyrrole network adsorbent material XTAPR in this embodiment has strong selectivity for Ga(III). In this embodiment, the adsorption performance of the multihydroxypyrrole network adsorbent material XTAPR on Ga(III) alone was determined: At room temperature, XTAPR (10 mg) and Ga(III) solution (pH=9, 10 mL, 51.82 mg / L) were added to a 15 mL centrifuge tube and shaken at 230 rpm for 24 h; the adsorbent was separated by centrifugation and the supernatant was obtained. SEM-EDS and XPS analyses were performed on the multi-hydroxypyrrole network adsorbent material XTAPR after gallium ion adsorption. (See attached image.) Figures 5-6 It was found that Ga was uniformly distributed on the XTAPR; the characteristic peak of Ga(3d) appeared in the XPS spectrum after Ga ions were adsorbed by XTAPR, which confirmed that the multi-hydroxypyrrole network adsorption material successfully adsorbed gallium ions. Using ICP OES analysis showed that the residual gallium ion concentration in the supernatant was 1.22 mg / L. The adsorption capacity of the nitrogen-oxygen-rich crosslinked COF adsorbent for Ga(III) was 50.60 mg / g, with an adsorption efficiency of 97.65%. The adsorbent was eluted with a desorption solution (40 mL) composed of 1% concentrated hydrochloric acid and 10% thiourea for 24 h. After centrifugation, the adsorbent was washed with distilled water until the solution was neutral, thus completing the regeneration of the adsorbent material XTAPR. After 10 repeatable experiments, the adsorption rate of Ga(III) in the 10th experiment was 83.72%.

[0017] Example 2: A method for preparing a multi-hydroxypyrrole network adsorbent material, the specific steps of which are as follows: (1) Dissolve (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal in a 7% hydrochloric acid solution to obtain a (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution with a concentration of 0.15 mol / L. (2) The (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution was heated to 50°C, and pyrrole and terephthalaldehyde were added sequentially and mixed evenly to obtain a mixed solution. The mixed solution was refluxed at 50°C for 75 h, cooled to room temperature, and the solid and liquid were separated. The solid was washed with deionized water until neutral and dried to obtain the multi-hydroxypyrrole network adsorbent material XTAPR. The concentration of pyrrole in the mixed solution was 0.15 mol / L, and the concentration of terephthalaldehyde was 0.15 mol / L. This embodiment measures the selective adsorption performance of the multihydroxypyrrole network adsorbent material XTAPR for Ga(III): At room temperature, XTAPR (40 mg) and the adsorption solution (pH=9, 40 mL) were added to a 50 mL centrifuge tube. The adsorption solution contained 56.33 mg / L Ga(III), 58.51 mg / L Ca(II), 53.08 mg / L V(V), and 66.44 mg / L As(V). The tube was shaken at 230 rpm for 24 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. The removal rates of Ga(III) were calculated to be 51.83%, Ca(II) 11.77%, V(V) 7.13%, and As(V) 14.09%. This shows that the multi-hydroxypyrrole network adsorbent material XTAPR in this embodiment has strong selectivity for Ga(III). In this embodiment, the adsorption performance of the multihydroxypyrrole network adsorbent material XTAPR on Ga(III) alone was determined: At room temperature, XTAPR (10 mg) and Ga(III) solution (pH=9, 10 mL, 65.91 mg / L) were added to a 15 mL centrifuge tube and shaken at 230 rpm for 24 h; the adsorbent was separated by centrifugation and the supernatant was obtained. Using ICP The OES determination showed that the residual gallium ion concentration in the supernatant was 4.12 mg / L, and the adsorption capacity of the nitrogen-oxygen-rich crosslinked COF adsorbent for Ga(III) was 61.79 mg / g, with an adsorption efficiency of 93.75%. The adsorbent was eluted with a desorption solution (40 mL) composed of 1% concentrated hydrochloric acid and 10% thiourea for 24 h. After centrifugation, the adsorbent was washed with distilled water until the solution was neutral, which completed the regeneration of the adsorbent material XTAPR. After 10 repeatable experiments, the adsorption rate of Ga(III) in the 10th adsorption was 74.98%.

[0018] Example 3: A method for preparing a multi-hydroxypyrrole network adsorbent material, the specific steps of which are as follows: (1) Dissolve (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal in a 9% hydrochloric acid solution to obtain a (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution with a concentration of 0.25 mol / L. (2) The (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution was heated to 70°C, and pyrrole and terephthalaldehyde were added sequentially and mixed evenly to obtain a mixed solution. The mixed solution was refluxed at 70°C for 65 h, cooled to room temperature, and the solid and liquid were separated. The solid was washed with deionized water until neutral and dried to obtain the multi-hydroxypyrrole network adsorbent material XTAPR. The concentration of pyrrole in the mixed solution was 0.25 mol / L, and the concentration of terephthalaldehyde was 0.25 mol / L. This embodiment measures the selective adsorption performance of the multihydroxypyrrole network adsorbent material XTAPR for Ga(III): At room temperature, XTAPR (40 mg) and the adsorption solution (pH=9, 40 mL) were added to a 50 mL centrifuge tube. The adsorption solution contained 51.42 mg / L Ga(III), 63.64 mg / L Ca(II), 56.51 mg / L V(V), and 70.51 mg / L As(V). The tube was shaken at 230 rpm for 24 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. The removal rates of Ga(III) were calculated to be 54.95%, Ca(II) 13.20%, V(V) 6.48%, and As(V) 12.24%. This shows that the multi-hydroxypyrrole network adsorbent material XTAPR in this embodiment has strong selectivity for Ga(III). In this embodiment, the adsorption performance of the multihydroxypyrrole network adsorbent material XTAPR on Ga(III) alone was determined: At room temperature, XTAPR (10 mg) and Ga(III) solution (pH=9, 10 mL, 53.56 mg / L) were added to a 15 mL centrifuge tube and shaken at 230 rpm for 24 h; the adsorbent was separated by centrifugation and the supernatant was obtained. Using ICP The OES determination showed that the residual gallium ion concentration in the supernatant was 8.31 mg / L, and the adsorption capacity of the nitrogen-oxygen-rich crosslinked COF adsorbent for Ga(III) was 61.79 mg / g, with an adsorption efficiency of 84.48%. The adsorbent was eluted with a desorption solution (40 mL) composed of 1% concentrated hydrochloric acid and 10% thiourea for 24 h. After centrifugation, the adsorbent was washed with distilled water until the solution was neutral, which completed the regeneration of the adsorbent material XTAPR. After 10 repeatable experiments, the adsorption rate of Ga(III) in the 10th adsorption was 69.29%.

[0019] 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 multi-hydroxypyrrole network adsorbent material, characterized in that, A multi-hydroxypyrrole network adsorbent material, denoted as XTAPR, was synthesized by heating and reflux using (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal, pyrrole, and terephthalaldehyde as ligands. The structural formula is as follows: 。 2. The method for preparing the polyhydroxypyrrole network adsorbent material according to claim 1, characterized in that, The specific steps are as follows: (1) Dissolve (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal in hydrochloric acid solution to obtain (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution; (2) The (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal solution was heated to 50~70℃, and pyrrole and terephthalaldehyde were added in sequence and mixed evenly to obtain a mixed solution. The mixed solution was refluxed at 50~70℃ for 67~77h, cooled to room temperature, and the solid and liquid were separated. The solid was washed with deionized water until neutral and dried to obtain the multi-hydroxypyrrole network adsorbent material XTAPR.

3. The method for preparing the polyhydroxypyrrole network adsorbent material according to claim 2, characterized in that: In step (1), the mass concentration of the hydrochloric acid solution is 7~10%, and the concentration of (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal is 0.15~0.25mol / L.

4. The method for preparing the polyhydroxypyrrole network adsorbent material according to claim 2, characterized in that: In step (2), the concentration of pyrrole in the mixed solution is 0.15~0.25mol / L, and the concentration of terephthalaldehyde is 0.15~0.25mol / L.

5. The application of the polyhydroxypyrrole network adsorbent material of claim 1 in the selective capture of gallium ions in solution.

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