A gallium ion adsorbing MXene-based composite aerogel material, a preparation method and application thereof

Abstract

This invention belongs to the field of gallium recovery and extraction technology, specifically relating to an MXene-based composite aerogel material for adsorbing gallium ions, its preparation method, and its application. The preparation method of this invention includes the following steps: (1) under ice bath ultrasonication, Ti3C2T x (1) The dispersion was added to a container containing PVA solution and sonicated to obtain a mixed solution; (2) The mixed solution obtained in step (1) was added to the 8-HQ monomer solution under ice bath sonication, and the container was transferred to a constant temperature water bath and allowed to stand; (3) Chemical crosslinking agent and catalyst were added sequentially under ice bath sonication, and after sonication, the container was transferred to a constant temperature water bath to react and obtain a hydrogel; (4) Washing; (5) Freeze-drying. The MXene-based composite aerogel material for adsorbing gallium ions of the present invention has a three-dimensional aerogel morphology, with a large specific surface area and abundant active sites, high adsorption capacity, stable structure, and easy recycling and reuse.

Description

Technical Field

[0001] This invention belongs to the field of gallium recovery and extraction technology, specifically relating to an MXene-based composite aerogel material that adsorbs gallium ions, its preparation method, and its application. Background Technology

[0002] The contradiction between limited natural gallium resources and rapidly growing market demand has drawn attention to gallium resource recycling. To avoid gallium shortages, researchers are focusing on recovering gallium from secondary resources. Notably, coal geologists have discovered significant gallium content in coal and identified several economically promising gallium-rich coal seams. Globally, gallium content in coal resources is estimated at approximately 100,000 tons. The Pingshuo No. 9 coal seam in the Ningwu coalfield of Shanxi Province has been reported as an ultra-large gallium-rich coal, with an average content of 0.025 mg / g. -1 After combustion, the average gallium content concentrated in the fly ash leachate reaches 0.03-0.1 mg / g. -1 It far exceeds the grade of industrial mining (0.03 mg g). -1 This scientific research lays the foundation for the production of gallium from coal. Typically, gallium in fly ash is leached into an adsorbed state using acid or alkaline leaching, followed by recovery through specific separation methods. Alkaline leaching yields gallium in an adsorbed state and encapsulated in amorphous silica, resulting in low leaching rates and a complex system. Acid leaching, on the other hand, extracts gallium entirely in an adsorbed state, facilitating subsequent gallium recovery. Adsorption methods offer advantages such as simple operation, high efficiency, and sustainability, making them a highly profitable gallium resource recovery method. The key to adsorption lies in the high selectivity, high adsorption capacity, and excellent recycling performance of the adsorbent. However, most adsorbents are powders with limited active sites, leading to severe dissolution and hindering recycling. Therefore, developing an adsorbent with abundant active sites and high adsorption capacity that is easily recoverable is crucial for gallium resource recovery.

[0003] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0004] The purpose of this invention is to provide an MXene-based composite aerogel material for adsorbing gallium ions, its preparation method and application, in order to solve or improve at least one of the problems of existing gallium adsorbents, such as most being powders, having a single active site, severe dissolution, and poor cycle performance.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing an MXene-based composite aerogel material that adsorbs gallium ions, comprising the following steps: (1) under ice bath ultrasonication, incorporating Ti3C2T x(1) Add the dispersion to a container containing PVA solution and sonicate to homogenize the system to obtain a mixed solution; (2) Add the mixed solution obtained in step (1) to the 8-HQ monomer solution under ice bath sonication for 30-60s, and then transfer the container to a constant temperature water bath at 20-25℃ and let it stand for 1-1.5h; (3) Add the chemical crosslinking agent and catalyst to the container in sequence under ice bath sonication, and then transfer it to a constant temperature water bath for reaction to obtain a hydrogel; (4) Wash the hydrogel obtained in step (3) to remove unreacted impurities; (5) Freeze-dry to obtain the MXene-based composite aerogel material adsorbing gallium ions.

[0006] Preferably, the Ti3C2T x The dispersion was prepared by the following steps: A. LiF was added to a polytetrafluoroethylene (PTFE) reactor containing hydrochloric acid, and the mixture was stirred to react; B. The PTFE reactor treated in step A was placed in a constant temperature water bath, and Ti3AlC2 was slowly added, while stirring to react; C. The reaction solution obtained in step B was centrifuged, and the solid obtained by centrifugation was washed with hydrochloric acid, followed by repeated washing with water until the supernatant turned black. The mixture was then sonicated, and the supernatant was centrifuged after sonication to obtain Ti3C2T. x Dispersion.

[0007] Preferably, in step A, the concentration of hydrochloric acid is 12 mol / L. -1 The stirring reaction time is 10 min; in step B, the temperature of the constant temperature water bath is 40℃, the stirring reaction time is 48 h, and the mass ratio of hydrochloric acid, LiF, and Ti3AlC2 is 7.2:1.6:1; in step C, the hydrochloric acid washing is performed three times, and the concentration of the hydrochloric acid is 1 mol L. -1 .

[0008] Preferably, the concentration of 8-HQ monomer in the 8-HQ monomer solution is 20-40 mg / mL. -1 The mass ratio of PVA to 8-HQ monomer is 0.125:1; the Ti3C2T x The volume ratio of the dispersion to the 8-HQ monomer solution is 1:2, and the Ti3C2T x Ti3C2T in dispersion x The concentration is 20 mg / mL -1 .

[0009] Preferably, in step (3), the chemical crosslinking agent is glutaraldehyde, and the catalyst is H3PO2; the volume ratio of glutaraldehyde to H3PO2 is 1:1; the mass-volume ratio of 8-HQ monomer to H3PO2 is 2:1, the mass of 8-HQ monomer is in mg, and the volume of H3PO2 is in μL.

[0010] Preferably, in step (3), the temperature of the water in the constant temperature water bath is 20-40℃, and the reaction time is 12-15h.

[0011] Preferably, the freeze-drying process specifically involves placing the hydrogel obtained in step (4) in a vacuum freeze dryer at -80°C, freezing it for 6 hours, and then turning on the vacuum mode of the freeze dryer for 24 hours.

[0012] Preferably, in step (4), the hydrogel obtained after step (3) is washed alternately with 5% ethanol and ultrapure water.

[0013] The present invention also provides an MXene-based composite aerogel material for adsorbing gallium ions, which adopts the following technical solution: an MXene-based composite aerogel material for adsorbing gallium ions, wherein the MXene-based composite aerogel material for adsorbing gallium ions is prepared by the method described above.

[0014] The present invention also provides an application of an MXene-based composite aerogel material for adsorbing gallium ions, which adopts the following technical solution: the application of the MXene-based composite aerogel material for adsorbing gallium ions as described above in the adsorption of gallium ions in fly ash acid leaching solution.

[0015] Beneficial effects:

[0016] This invention uses Ti3C2T x Using 8-HQ as the functional monomer and PVA as the physical crosslinking agent, 8-HQ is assembled onto the entangled PVA molecular chains of Ti3C2T through electrostatic and hydrogen bonding interactions. x On the nanosheets, H3PO2 is used as a catalyst and glutaraldehyde is used as a chemical crosslinking agent for crosslinking polymerization. Finally, the MXene-based composite aerogel material (in a three-dimensional aerogel morphology) adsorbing gallium ions is obtained by freeze drying. The MXene-based composite aerogel material can adsorb gallium ions in fly ash acid leaching solution.

[0017] The MXene-based composite aerogel material for adsorbing gallium ions prepared in this invention has advantages such as simple preparation method and good recyclability. Compared with other materials for adsorbing gallium ions, it has better recyclability. After five cycles, the material remains relatively intact, and its adsorption capacity is still 95.64% of the initial adsorption capacity.

[0018] The MXene-based composite aerogel material for adsorbing gallium ions prepared in this invention can effectively adsorb gallium ions. It exhibits a high adsorption capacity for gallium ions, a faster and simpler preparation process, and can be recycled multiple times, making it practically applicable.

[0019] The MXene-based composite aerogel material prepared by this invention exhibits a higher adsorption capacity than current gallium ion adsorbents, reaching 132.49 mg g for gallium ions. -1 The adsorption equilibrium was reached after 6 hours.

[0020] The MXene-based composite aerogel material for adsorbing gallium ions prepared in this invention achieves the maximum adsorption capacity for Ga(III) at pH 3. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0022] Figure 1 This is a schematic diagram illustrating the reaction principle of an MXene-based composite aerogel material for adsorbing gallium ions, provided in one embodiment of the present invention.

[0023] Figure 2 The synthesis route diagram of MPHG-40 provided in Embodiment 1 of the present invention;

[0024] Figure 3 The adsorption kinetics curve of gallium by MPHG-20 provided in Example 2;

[0025] Figure 4 The adsorption kinetics curve of gallium by MPHG-40 provided in Example 1 of this invention;

[0026] Figure 5 The adsorption isotherm of gallium by MPHG-20 provided in Example 2;

[0027] Figure 6 The adsorption isotherm of gallium by MPHG-40 provided in Embodiment 1 of the present invention;

[0028] Figure 7 The graph shows the adsorption performance of MPHG-20 in Example 2 and MPHG-40 in Example 1 on gallium at different acidities. Figure 7 In the two bar charts corresponding to the same pH, the left bar chart represents the adsorption amount (Q) of MPHG-40, and the right bar chart represents the adsorption amount (Q) of MPHG-20.

[0029] Figure 8 This is an adsorption-desorption cycle experiment diagram of gallium ions adsorbed by MPHG-40 provided in Example 1 of the present invention;

[0030] Figure 9 The adsorption-desorption cycle experiment diagram of gallium ions adsorbed by M-40HQ provided for Comparative Example 1;

[0031] Figure 10 The adsorption-desorption cycle experimental diagram of gallium ions adsorbed by 5PM-HQ is provided for Comparative Example 2.

[0032] Figure 11 The images show the physical samples of MPHG-40 provided in Example 1, M-40HQ provided in Comparative Example 1, and 5PM-HQ provided in Comparative Example 2 before and after cyclic adsorption of gallium ions. Figures (a) and (b) show the samples of M-40HQ before and after cyclic adsorption, Figures (c) and (d) show the samples of 5PM-HQ before and after cyclic adsorption, and Figures (e) and (f) show the samples of MPHG-40 before and after cyclic adsorption.

[0033] Figure 12 XPS spectra provided for MPHG-40 in Embodiment 1, 5PM-HQ in Comparative Example 2, and M-40HQ in Comparative Example 1; wherein (a) is the XPS spectrum provided by M-40HQ, (b) is the XPS spectrum provided by 5PM-HQ, and (c) is the XPS spectrum provided by MPHG-40.

[0034] Figure 13 The images shown are FESEM images of MPHG-40 and MPHG-20 provided in Embodiments 1 and 2 of the present invention, wherein Figure (a) is an FESEM image of MPHG-20 and Figure (b) is an FESEM image of MPHG-40. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0036] The present invention will now be described in detail with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0037] This invention addresses at least one of the following problems of existing adsorbents: they are mostly in powder form, have a single active site, suffer severe dissolution loss (due to poor stability of the adsorbent, the amount of adsorbent recovered during recycling is significantly reduced), and have poor cycling performance. It provides a method for preparing an MXene-based composite aerogel material for adsorbing gallium ions.

[0038] The preparation method of the MXene-based composite aerogel material adsorbed with gallium ions according to the present invention includes the following steps: (1) under ice bath ultrasonication, Ti3C2T x(1) Add the dispersion (i.e., MXene dispersion) to a container containing PVA solution and sonicate to homogenize the system to obtain a mixed solution; (2) Add the mixed solution obtained in step (1) to the 8-HQ monomer solution under ice bath sonication for 30-60s (e.g., 30s, 40s, 50s or 60s), then transfer the container to a constant temperature water bath at 20-25℃ (e.g., 20℃, 21℃, 22℃, 23℃, 24℃ or 25℃) and let it stand. 1-1.5h (e.g., 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h); (3) Under ice bath sonication, chemical crosslinking agent and catalyst are added to the container in sequence, and after sonication (e.g., the sonication time can be 30s), the mixture is transferred to a constant temperature water bath for reaction to obtain hydrogel; (4) The hydrogel obtained by step (3) is washed to remove unreacted impurities; (5) Freeze-drying is performed to obtain MXene-based composite aerogel material with adsorbed gallium ions.

[0039] In step (2), the constant temperature water bath can keep the reaction at a constant temperature throughout the process. The temperature of the constant temperature water bath can be around room temperature. Too low a temperature may reduce the gelation speed. In step (2), at a temperature of 20-25℃ in the constant temperature water bath, the physical cross-linking network of the current material can be basically completed in about 1 hour, so as to carry out the next step of chemical cross-linking. The standing time can be appropriately extended.

[0040] The method for preparing MXene-based composite aerogel materials with adsorbed gallium ions according to embodiments of the present invention utilizes a two-dimensional layered nanomaterial Ti3C2T with advantages such as large specific surface area, abundant active sites, easily modifiable surface functional groups, and adjustable interlayer spacing. x Using 8-HQ, which has a special recognition function for gallium ions, as the functional monomer and PVA as the physical crosslinking agent, 8-HQ is assembled on the entangled PVA molecular chains of Ti3C2T as the material matrix through electrostatic and hydrogen bonding interactions. x On nanosheets, cross-linking polymerization is carried out with a chemical cross-linking agent in the presence of a catalyst, and finally, MXene-based composite aerogel material with adsorbed gallium ions is obtained by freeze-drying (reaction principle as follows). Figure 1 As shown, this MXene-based composite aerogel material for adsorbing gallium ions can be used for the adsorption of gallium ions and is expected to be applied to the adsorption of gallium ions in fly ash acid leaching solution.

[0041] The method for preparing MXene-based composite aerogel materials for adsorbing gallium ions according to embodiments of the present invention yields MXene-based composite aerogel materials with a three-dimensional aerogel morphology, possessing a large specific surface area and abundant active sites, thus exhibiting high adsorption capacity. Compared to currently used powder-based adsorbents, it has a more stable structure (maintaining structural integrity well even after multiple cycles of use), and is easy to recycle and reuse.

[0042] In a preferred embodiment of the preparation method of the gallium ion-adsorbed MXene-based composite aerogel material of the present invention, Ti3C2T x The dispersion was prepared by the following steps: A. LiF was added to a polytetrafluoroethylene (PTFE) reactor containing hydrochloric acid, and the mixture was stirred to react; B. The PTFE reactor treated in step A was placed in a constant temperature water bath, and Ti3AlC2 was slowly added, while stirring to react; C. The reaction solution obtained in step B was centrifuged, and hydrochloric acid was added to the centrifuged solid for at least one wash (preferably, hydrochloric acid was used to wash the centrifuged solid three times). Then, water was added and the mixture was washed repeatedly (multiple times) until the supernatant turned black (at which point the pH of the supernatant was basically neutral). After that, the mixture was sonicated (without removing the black supernatant) and the upper liquid was centrifuged after sonication to obtain Ti3C2T. x Dispersion.

[0043] In a preferred embodiment of the method for preparing the gallium ion-adsorbed MXene-based composite aerogel material of the present invention, in step A, the concentration of hydrochloric acid is 12 mol / L. -1 The stirring reaction time was 10 min; in step B, the temperature of the constant temperature water bath was 40℃, the stirring reaction time was 48 h, and the mass ratio of hydrochloric acid, LiF and Ti3AlC2 was 7.2:1.6:1; in step C, the concentration of hydrochloric acid was 1 mol L. -1 ;

[0044] In a preferred embodiment of the method for preparing the gallium ion-adsorbed MXene-based composite aerogel material of the present invention, the concentration of 8-HQ monomer in the 8-HQ monomer solution is 20-40 mg / mL. -1 (For example, 20 mg mL) -1 30mg / mL -1 Or 40mg / mL -1 The mass ratio of PVA to 8-HQ monomers was 0.125:1; Ti3C2T x The volume ratio of the dispersion to the 8-HQ monomer solution was 1:1, Ti3C2T x Ti3C2T in dispersion x The concentration is 20 mg / mL -1Among these, with the same amount of 8-HQ, decreasing the concentration of 8-HQ monomer is equivalent to increasing the amount of water in the solution, resulting in a larger and more loosely structured aerogel; increasing the concentration of 8-HQ monomer will cause 8-HQ monomer to precipitate (40 mg / mL). -1 (This refers to the saturation concentration at the current aerogel volume). Furthermore, a higher mass ratio of PVA to 8-HQ will result in PVA occupying more Ti3C2T. x The active sites on the surface lead to the precipitation of 8-HQ. Insufficient PVA content hinders the formation of a complete physical cross-linked network. Furthermore, a decrease in 8-HQ content reduces the material's adsorption performance, while excessive content leads to precipitation during gelation; 40 mg is the current saturation value.

[0045] In a preferred embodiment of the preparation method of the MXene-based composite aerogel material for adsorbing gallium ions of the present invention, the chemical crosslinking agent is glutaraldehyde, and the catalyst is H3PO2; the volume ratio of glutaraldehyde to H3PO2 is 1:1. The amount of catalyst affects the rate of chemical crosslinking (changes in the amount of catalyst do not affect the product performance). While reducing the amount of PVA, the physical crosslinking agent, may increase the adsorption capacity of the material, it will affect the overall stability and structure of the material. Conversely, excessively high amounts of PVA will significantly reduce the adsorption capacity. As for glutaraldehyde, the chemical crosslinking network it forms exists simultaneously in PVA, 8-HQ, and Ti3C2T. x Therefore, changes in the amount of PVA used will also affect the final chemical cross-linking network of the material, and thus affect the final structural stability of the material.

[0046] In a preferred embodiment of the preparation method of the MXene-based composite aerogel material for adsorbing gallium ions of the present invention, the mass-to-volume ratio of 8-HQ monomer to H3PO2 is 2:1, the mass of 8-HQ monomer is expressed in mg, and the volume of H3PO2 is expressed in μL.

[0047] In a preferred embodiment of the method for preparing the MXene-based composite aerogel material with adsorbed gallium ions according to the present invention, in step (3), the temperature of the water in the constant temperature water bath is 20-40℃ (e.g., 20℃, 25℃, 30℃, 35℃ or 40℃), and the reaction time is 12-15h (e.g., 12h, 13h, 14h or 15h). However, if the water bath temperature is greater than 40℃, it can easily cause Ti3C2T... x The oxidation of the material matrix alters the material matrix; the reaction time in this step ensures sufficient chemical crosslinking, while a shortened reaction time may result in incomplete chemical crosslinking.

[0048] In a preferred embodiment of the preparation method of the MXene-based composite aerogel material adsorbed by gallium ions of the present invention, the freeze-drying is specifically performed as follows: the hydrogel obtained by step (4) is placed in a vacuum freeze dryer at -80°C and frozen for 6 hours, and then the vacuum mode of the vacuum freeze dryer is turned on and maintained for 24 hours.

[0049] In a preferred embodiment of the method for preparing the MXene-based composite aerogel material with adsorbed gallium ions of the present invention, in step (4), the hydrogel obtained after treatment in step (3) is washed alternately with 5% ethanol and ultrapure water.

[0050] The present invention also proposes an MXene-based composite aerogel material for adsorbing gallium ions. The MXene-based composite aerogel material for adsorbing gallium ions in the embodiments of the present invention is prepared by the method described above.

[0051] The MXene-based composite aerogel material for adsorbing gallium ions of the present invention exhibits a three-dimensional aerogel morphology, possessing a large specific surface area and abundant active sites, thus demonstrating a high adsorption capacity. Compared to currently used predominantly powder-based adsorbents, it has a more stable structure, is easier to recover (significantly reducing solubility loss), and is recyclable.

[0052] The MXene-based composite aerogel material for adsorbing gallium ions of the present invention exhibits good recyclability. After five cycles, the material remains relatively intact, with an adsorption capacity still reaching 95.64% of the initial adsorption capacity. The adsorption capacity of the MXene-based composite aerogel material for adsorbing gallium ions of the present invention can reach 132.49 mg / g. -1 The adsorption time reaches adsorption equilibrium in 6 hours; the MXene-based composite aerogel material for adsorbing gallium ions of the present invention achieves the maximum adsorption capacity for Ga(III) at pH 3.

[0053] The present invention also proposes the application of the MXene-based composite aerogel material for adsorbing gallium ions as described above, and the application of the MXene-based composite aerogel material for adsorbing gallium ions in fly ash acid leaching solution as described above.

[0054] The following detailed description of the MXene-based composite aerogel material for adsorbing gallium ions, its preparation method, and its application are illustrated by specific embodiments of the present invention.

[0055] The following ingredients were used in the following examples: titanium aluminide (Ti3AlC2, 400 mesh) powder was purchased from Jilin Eleven Technology Co., Ltd.; hydrochloric acid (HCl, analytical grade) was purchased from Luoyang Chemical Reagent Factory; lithium fluoride (LiF, RG), gallium oxide (Ga2O3, RG), 8-hydroxyquinoline (8-HQ, 99%), glutaraldehyde (GA, 50%), and hypophosphorous acid (H3PO2, 50%) were purchased from Adamas Reagent Co., Ltd.; polyvinyl alcohol (PVA, ~14500) was purchased from China Aladdin Reagent Co., Ltd.; and ultrapure water (99.99%) was prepared in-house using equipment purchased from UPU Ultrapure Technology Co., Ltd.

[0056] Example 1

[0057] The preparation method of the gallium ion-adsorbed MXene-based composite aerogel material in this embodiment includes the following steps (synthesis route diagram is shown in the attached figure of the specification). Figure 2 As shown):

[0058] (1) Etching of MXene

[0059] A. Add 1.6g LiF to a container containing 20mL of 12mol L -1 In a polytetrafluoroethylene reactor containing hydrochloric acid, the mixture was stirred and reacted for 10 minutes.

[0060] B. Place the reactor in a 40°C constant temperature water bath, slowly add 1g Ti3AlC2, and stir for 48h;

[0061] C. Using 1 mol L -1 The sample was repeatedly washed with hydrochloric acid and ultrapure water (first with hydrochloric acid three times, then with ultrapure water multiple times) until the supernatant turned black. The product (including the black supernatant) was ultrasonicated and centrifuged to obtain the etched MXene aqueous solution. This solution was prepared to a concentration of 20 mg / mL. -1 Ti3C2T x Dispersion.

[0062] (2) Weigh a certain mass of PVA and disperse it in ultrapure water. First, stir in a water bath at 60℃ for one hour to allow the PVA particles to fully swell. Then, stir in a water bath at 90℃ for 2 hours until completely dissolved into a transparent solution, yielding 50 mg / mL of PVA. -1 PVA aqueous solution.

[0063] (3) 1 mL of 20 mg / mL solution was added under ultrasound in an ice bath. -1 Ti3C2T x Add 0.1 mL of PVA solution (50 mg / mL) to the dispersion. -1 In a small cylindrical bottle, the system is homogenized by sonication to obtain a mixed solution;

[0064] (4) A certain mass of 8-HQ monomer was weighed and ultrasonically dispersed in anhydrous ethanol to obtain 40 mg / mL. -1 8-HQ monomer solution.

[0065] (5) Under ice bath sonication, add the mixed solution obtained after step (3) containing 1 mL of 40 mg / mL solution. -1 The 8-HQ monomer solution was placed in a small cylindrical bottle, sonicated in an ice bath for 30 seconds, and then transferred to a 20°C constant temperature water bath and allowed to stand for 1 hour.

[0066] (6) Under ice bath sonication, add 20 μL of glutaraldehyde and 20 μL of H3PO2 to the small cylindrical bottle in sequence. After sonication for 30 seconds, transfer to a 40℃ constant temperature water bath and react for 12 hours.

[0067] (7) After the reaction is complete, the hydrogel is washed alternately with 5% ethanol and ultrapure water to remove unreacted impurities;

[0068] (8) The cleaned hydrogel was placed in a vacuum freeze dryer at -80°C and frozen for 6 hours. Then, the vacuum mode of the vacuum freeze dryer was turned on to start supercritical freeze drying for 24 hours. The MXene-based composite aerogel material adsorbing gallium ions (abbreviated as MPHG-40) of this embodiment was obtained.

[0069] Take a 100mL Erlenmeyer flask and add 50mL of a solution with a concentration of 50mg / L. -1 A gallium ion solution (pH=3) was prepared, and 5 mg of MPHG-40 (as described in this example) was added to an Erlenmeyer flask; the solution was then subjected to an oscillation at 25°C and a frequency of 200 rpm. -1 Adsorbed in a shaker for 24 hours.

[0070] Experimental results show that MPHG-40 in this embodiment, at a concentration of 50 mg / L, is effective. -1 The adsorption capacity of gallium ions in the gallium ion solution was 132.49 mg g. -1 .

[0071] Example 2

[0072] The preparation method of the gallium ion-adsorbed MXene-based composite aerogel material in this comparative example includes the following steps:

[0073] (1) Etching of MXene

[0074] A. Add 1.6g LiF to a container containing 20mL of 12mol L -1 In a polytetrafluoroethylene reactor containing hydrochloric acid, the mixture was stirred and reacted for 10 minutes.

[0075] B. Place the reactor in a 40°C constant temperature water bath, slowly add 1g Ti3AlC2, and stir for 48h;

[0076] C. Using 1 mol L -1 The sample was repeatedly washed with hydrochloric acid and ultrapure water (first with hydrochloric acid three times, then with ultrapure water multiple times) until the supernatant turned black. The product (including the black supernatant) was ultrasonicated and centrifuged to obtain the etched MXene aqueous solution. This solution was prepared to a concentration of 20 mg / mL. -1 Ti3C2T x Dispersion.

[0077] (2) Under sonication in an ice bath, 1 mL of 20 mg / mL solution was added. -1 Ti3C2T x Add 0.1 mL of PVA solution (50 mg / mL) to the dispersion. -1 In a small cylindrical bottle, the system is homogenized by sonication to obtain a mixed solution;

[0078] (3) Under ice bath sonication, add the above mixed solution containing 1 mL of 40 mg / mL solution. -1 In the 8-HQ monomer solution, after sonication in an ice bath for 30 seconds, the small cylindrical bottle was transferred to a 20°C constant temperature water bath and allowed to stand for 1 hour.

[0079] (4) Under ice bath sonication, add 20 μL of glutaraldehyde and 20 μL of H3PO2 to the small cylindrical bottle in sequence. After sonication for 30 seconds, transfer to a 20℃ constant temperature water bath and react for 12 hours.

[0080] (5) After the reaction is complete, the hydrogel is washed with 5% ethanol and ultrapure water alternately to remove unreacted impurities;

[0081] (6) The cleaned hydrogel was placed in a vacuum freeze dryer at -80℃ and frozen for 6 hours. Then, the vacuum mode of the vacuum freeze dryer was turned on to start supercritical freeze drying for 24 hours. The MXene-based composite aerogel material with adsorbed gallium ions (abbreviated as MPHG-20) was obtained.

[0082] Take a 100mL Erlenmeyer flask and add 50mL of a solution with a concentration of 50mg / L. -1 A gallium ion solution (pH=3) was prepared, and 5 mg of MPHG-20 (as described in this example) was added to an Erlenmeyer flask; the solution was then subjected to an oscillation at 25°C and a frequency of 200 rpm. -1 Adsorbed in a shaker for 24 hours.

[0083] Experimental results show that MPHG-20 in this embodiment, at a concentration of 50 mg / L, is effective. -1 The adsorption capacity of gallium ions in the gallium ion solution was 101.24 mg / g. -1 .

[0084] The only difference between this embodiment and Example 1 is that the crosslinking temperature is different (i.e., the crosslinking temperature is different after adding chemical crosslinking agent and catalyst), and all other aspects are consistent with Example 1.

[0085] Comparative Example 1

[0086] The preparation method of the gallium ion-adsorbed MXene-based composite aerogel material in this embodiment includes the following steps:

[0087] (1) Etching of MXene

[0088] A. Add 1.6g LiF to a container containing 20mL of 12mol L -1 In a polytetrafluoroethylene reactor containing hydrochloric acid, the mixture was stirred and reacted for 10 minutes.

[0089] B. Place the reactor in a 40°C constant temperature water bath, slowly add 1g Ti3AlC2, and stir for 48h;

[0090] C. Using 1 mol L -1 The sample was repeatedly washed with hydrochloric acid and ultrapure water (first with hydrochloric acid three times, then with ultrapure water multiple times) until the supernatant turned black. The product (including the black supernatant) was ultrasonicated and centrifuged to obtain the etched MXene aqueous solution. This solution was prepared to a concentration of 20 mg / mL. -1 Ti3C2T x Dispersion.

[0091] (2) A certain mass of 8-HQ monomer was weighed and ultrasonically dispersed in anhydrous ethanol to obtain 40 mg / mL. -1 8-HQ monomer solution.

[0092] (3) 1 mL of 20 mg / mL solution was added under ultrasound in an ice bath. -1 Ti3C2T x Add 1 mL of 8-HQ monomer solution (40 mg / mL) to the dispersion. -1 After being subjected to ultrasound in an ice bath for 30 seconds, the sample was placed in a 20°C constant temperature water bath and left to stand for 12 hours.

[0093] (4) Wash the resulting hydrogel alternately with 5% ethanol and ultrapure water to remove unreacted impurities.

[0094] (5) The cleaned hydrogel was placed in a vacuum freeze dryer at -80℃ and frozen for 6 hours. Then, the vacuum mode of the vacuum freeze dryer was turned on to start supercritical freeze drying for 24 hours. The MXene-based composite aerogel material with adsorbed gallium ions (referred to as M-40HQ) was obtained.

[0095] Take a 100mL Erlenmeyer flask and add 50mL of a solution with a concentration of 50mg / L. -1A gallium ion solution (pH=3) was prepared, and 5 mg of M-40HQ (as described in this example) was added to an Erlenmeyer flask; the solution was then subjected to an oscillation at 25°C and a frequency of 200 rpm. -1 Adsorbed in a shaker for 24 hours.

[0096] Experimental results show that the M-40HQ in this embodiment, at a concentration of 50 mg / L, is effective. -1 The adsorption capacity of gallium ions in the gallium ion solution was 144.79 mg g. -1 .

[0097] Comparative Example 2

[0098] The preparation method of the gallium ion-adsorbed MXene-based composite aerogel material in this embodiment includes the following steps:

[0099] (1) Etching of MXene

[0100] A. Add 1.6g LiF to a container containing 20mL of 12mol L -1 In a polytetrafluoroethylene reactor containing hydrochloric acid, the mixture was stirred and reacted for 10 minutes.

[0101] B. Place the reactor in a 40°C constant temperature water bath, slowly add 1g Ti3AlC2, and stir for 48h;

[0102] C. Wash repeatedly with 1 mol / L hydrochloric acid and ultrapure water (wash three times with hydrochloric acid, then wash multiple times with ultrapure water) until the supernatant turns black. Sonicate the product (including the black supernatant) and centrifuge to obtain the etched MXene aqueous solution. Prepare a 20 mg / mL solution. -1 Ti3C2T x Dispersion.

[0103] (2) A certain mass of 8-HQ monomer was weighed and ultrasonically dispersed in anhydrous ethanol to obtain 40 mg / mL. -1 8-HQ monomer solution.

[0104] (3) Weigh a certain mass of PVA and disperse it in ultrapure water. First, stir in a water bath at 60℃ for one hour to allow the PVA particles to fully swell. Then, stir in a water bath at 90℃ for 2 hours until completely dissolved into a transparent solution, yielding 50 mg / mL of PVA. -1 PVA aqueous solution.

[0105] (4) Under ice bath sonication, 1 mL of 20 mg mL of the solution was added. -1 Ti3C2T x Add 0.1 mL of PVA solution (50 mg / mL) to the dispersion. -1 The mixture was placed in a small cylindrical bottle and sonicated for 1 hour to homogenize the system, resulting in a mixed solution.

[0106] (5) Under ice bath sonication, add the mixed solution obtained after step (4) to a solution containing 1 mL of 40 mg / mL solution. -1 In 8-HQ solution, sonicate for 30 seconds.

[0107] (6) Seal the small cylindrical bottle and transfer it into a 20°C constant temperature water bath. Let it stand for 12 hours to allow it to react fully.

[0108] (7) Wash the obtained hydrogel alternately with 5% ethanol and ultrapure water to remove unreacted impurities.

[0109] (8) The cleaned hydrogel was placed in a vacuum freeze dryer at -80℃ and frozen for 6 hours. Then, the vacuum mode of the vacuum freeze dryer was turned on to start supercritical freeze drying for 24 hours. MXene-based composite aerogel material with adsorbed gallium ions (referred to as 5PM-HQ) was obtained.

[0110] Take a 100mL Erlenmeyer flask and add 50mL of a solution with a concentration of 50mg / L. -1 A gallium ion solution (pH=3) was prepared by adding 5 mg of 5PM-HQ (as described in this example) to an Erlenmeyer flask; the solution was then subjected to an oscillation at 25°C and a frequency of 200 rpm. -1 Adsorbed in a shaker for 24 hours.

[0111] Experimental results show that the 5PM-HQ in this embodiment, at a concentration of 50 mg / L, is effective. -1 The adsorption capacity of gallium ions in the gallium ion solution was 126.72 mg / g. -1 .

[0112] Comparative Example 3

[0113] The preparation method of the gallium ion-adsorbed MXene-based composite aerogel material in this comparative example includes the following steps:

[0114] (1) Etching of MXene

[0115] A. Add 1.6g LiF to a container containing 20mL of 12mol L -1 In a polytetrafluoroethylene reactor containing hydrochloric acid, the mixture was stirred and reacted for 10 minutes.

[0116] B. Place the reactor in a 40°C constant temperature water bath, slowly add 1g Ti3AlC2, and stir for 48h;

[0117] C. Using 1 mol L -1The sample was repeatedly washed with hydrochloric acid and ultrapure water (first with hydrochloric acid three times, then with ultrapure water multiple times) until the supernatant turned black. The product (including the black supernatant) was ultrasonicated and centrifuged to obtain the etched MXene aqueous solution. This solution was prepared to a concentration of 20 mg / mL. -1 Ti3C2T x Dispersion.

[0118] (2) A certain mass of 8-HQ monomer was weighed and ultrasonically dispersed in anhydrous ethanol to obtain 10 mg mL -1 8-HQ monomer solution.

[0119] (3) 1 mL of 20 mg / mL solution was added under ultrasound in an ice bath. -1 Ti3C2T x Add the dispersion to 1 mL of 8-HQ monomer solution, sonicate in an ice bath for 30 seconds, then place in a 20℃ constant temperature water bath and let stand for 12 hours.

[0120] (4) Wash the resulting hydrogel alternately with 5% ethanol and ultrapure water to remove unreacted impurities.

[0121] (5) The cleaned hydrogel was placed in a vacuum freeze dryer at -80℃ and frozen for 6 hours. Then, the vacuum mode of the vacuum freeze dryer was turned on to start supercritical freeze drying for 24 hours. The MXene-based composite aerogel material with adsorbed gallium ions (referred to as M-10HQ) was obtained.

[0122] Take a 100mL Erlenmeyer flask and add 50mL of a solution with a concentration of 50mg / L. -1 A gallium ion solution (pH=3) was prepared by adding 5 mg of M-10HQ (the comparative example) to an Erlenmeyer flask; the solution was then subjected to an oscillation at 25°C and a frequency of 200 rpm. -1 Adsorbed in a shaker for 24 hours.

[0123] Experimental results show that the M-10HQ in this comparative example, at a concentration of 50 mg / L, is effective. -1 The adsorption capacity of gallium ions in the gallium ion solution was 111.74 mg g. -1 .

[0124] The only difference between this comparative example and Comparative Example 1 is the amount of 8-HQ monomer used; all other aspects remain the same. The 8-HQ monomer provides the main active sites for gallium ion adsorption, similar to Ti3C2T. x Electrostatic attraction between these molecules forms a hydrogen bond network, which determines the stability of the aerogel material structure. Reducing the amount of 8-HQ monomer decreases the stability of the prepared M-10HQ, resulting in a looser structure and reduced adsorption performance.

[0125] Comparative Example 4

[0126] The preparation method of the gallium ion-adsorbed MXene-based composite aerogel material in this comparative example includes the following steps:

[0127] (1) Etching of MXene

[0128] A. Add 1.6g LiF to a container containing 20mL of 12mol L -1 In a polytetrafluoroethylene reactor containing hydrochloric acid, the mixture was stirred and reacted for 10 minutes.

[0129] B. Place the reactor in a 40°C constant temperature water bath, slowly add 1g Ti3AlC2, and stir for 48h;

[0130] C. Using 1 mol L -1 The sample was repeatedly washed with hydrochloric acid and ultrapure water (first with hydrochloric acid three times, then with ultrapure water multiple times) until the supernatant turned black. The product (including the black supernatant) was ultrasonicated and centrifuged to obtain the etched MXene aqueous solution. This solution was prepared to a concentration of 20 mg / mL. -1 Ti3C2T x Dispersion.

[0131] (2) A certain mass of 8-HQ monomer was weighed and ultrasonically dispersed in anhydrous ethanol to obtain 20 mg mL -1 8-HQ monomer solution.

[0132] (3) 1 mL of 20 mg / mL solution was added under ultrasound in an ice bath. -1 Ti3C2T x Add the dispersion to 1 mL of 8-HQ monomer solution, sonicate in an ice bath for 30 seconds, then place in a 20℃ constant temperature water bath and let stand for 12 hours.

[0133] (4) Wash the resulting hydrogel alternately with 5% ethanol and ultrapure water to remove unreacted impurities.

[0134] (5) The cleaned hydrogel was placed in a vacuum freeze dryer at -80℃ and frozen for 6 hours. Then, the vacuum mode of the vacuum freeze dryer was turned on to start supercritical freeze drying for 24 hours. The MXene-based composite aerogel material with adsorbed gallium ions (referred to as M-20HQ) was obtained.

[0135] Take a 100mL Erlenmeyer flask and add 50mL of a solution with a concentration of 50mg / L. -1 A gallium ion solution (pH=3) was prepared by adding 5 mg of M-20HQ (the comparative example) to an Erlenmeyer flask; the solution was prepared at 25°C with an oscillation frequency of 200 rpm. -1 Adsorbed in a shaker for 24 hours.

[0136] Experimental results show that the M-20HQ in this comparative example, at a concentration of 50 mg / L, is effective. -1 The adsorption capacity of gallium ions in the gallium ion solution was 128.62 mg / g. -1 .

[0137] The only difference between this comparative example and Comparative Example 1 is the amount of 8-HQ monomer used; all other aspects remain the same. The 8-HQ monomer provides the main active sites for gallium ion adsorption, similar to Ti3C2T. x Electrostatic attraction between the atoms forms a hydrogen bond network, which determines the stability of the aerogel material structure. Reducing the amount of 8-HQ monomer will decrease the stability of the prepared M-20HQ, make the structure more loose, and reduce the adsorption performance.

[0138] Comparative Example 5

[0139] The preparation method of the gallium ion-adsorbed MXene-based composite aerogel material in this comparative example includes the following steps:

[0140] (1) Etching of MXene

[0141] A. Add 1.6g LiF to a container containing 20mL of 12mol L -1 In a polytetrafluoroethylene reactor containing hydrochloric acid, the mixture was stirred and reacted for 10 minutes.

[0142] B. Place the reactor in a 40°C constant temperature water bath, slowly add 1g Ti3AlC2, and stir for 48h;

[0143] C. Wash repeatedly with 1 mol / L hydrochloric acid and ultrapure water (wash three times with hydrochloric acid, then wash multiple times with ultrapure water) until the supernatant turns black. Sonicate the product (including the black supernatant) and centrifuge to obtain the etched MXene aqueous solution. Prepare a 20 mg / mL solution. -1 Ti3C2T x Dispersion.

[0144] (2) A certain mass of 8-HQ monomer was weighed and ultrasonically dispersed in anhydrous ethanol to obtain 40 mg / mL. -1 8-HQ monomer solution.

[0145] (3) Weigh a certain mass of PVA and disperse it in ultrapure water. First, stir in a water bath at 60℃ for one hour to allow the PVA particles to fully swell. Then, stir in a water bath at 90℃ for 2 hours until completely dissolved into a transparent solution, yielding 50 mg / mL of PVA. -1 PVA aqueous solution.

[0146] (4) Under ice bath sonication, 1 mL of 20 mg mL of the solution was added. -1 Ti3C2Tx Add 0.02 mL of PVA solution (50 mg / mL) to the dispersion. -1 The mixture was placed in a small cylindrical bottle and sonicated for 1 hour to homogenize the system, resulting in a mixed solution.

[0147] (5) Under ice bath sonication, add the mixed solution obtained after step (4) to a solution containing 1 mL of 40 mg / mL solution. -1 In 8-HQ solution, sonicate for 30 seconds.

[0148] (6) Seal the small cylindrical bottle and transfer it into a 20°C constant temperature water bath. Let it stand for 12 hours to allow it to react fully.

[0149] (7) Wash the obtained hydrogel alternately with 5% ethanol and ultrapure water to remove unreacted impurities.

[0150] (8) The cleaned hydrogel was placed in a vacuum freeze dryer at -80℃ and frozen for 6 hours. Then, the vacuum mode of the vacuum freeze dryer was turned on to start supercritical freeze drying for 24 hours. MXene-based composite aerogel material with adsorbed gallium ions (abbreviated as 1PM-HQ) was obtained.

[0151] Take a 100mL Erlenmeyer flask and add 50mL of a solution with a concentration of 50mg / L. -1 A gallium ion solution (pH = 3) was prepared by adding 5 mg of 1 PM-HQ (the comparative example) to an Erlenmeyer flask; the solution was then subjected to an oscillation at 25 °C and a shaking frequency of 200 rpm. -1 Adsorbed in a shaker for 24 hours.

[0152] Experimental results show that: the 1PM-HQ in this comparative example, at a concentration of 50 mg / L... -1 The adsorption capacity of gallium ions in the gallium ion solution was 163.15 mg g. -1 .

[0153] The only difference between this comparative example and Comparative Example 2 is the amount of PVA used; all other aspects are the same as in Comparative Example 2. PVA is the main component that forms the physical cross-linked structure of the material. An appropriate amount of PVA can ensure the adsorption capacity of the material while giving it a more stable structure. In this comparative example, although the adsorption capacity of gallium ions increased after reducing the amount of PVA, the reduced amount of PVA led to a decrease in the degree of physical cross-linking in the structure, resulting in a decrease in the stability of 1PM-HQ.

[0154] Comparative Example 6

[0155] The preparation method of the gallium ion-adsorbed MXene-based composite aerogel material in this comparative example includes the following steps:

[0156] (1) Etching of MXene

[0157] A. Add 1.6g LiF to a container containing 20mL of 12mol L -1 In a polytetrafluoroethylene reactor containing hydrochloric acid, the mixture was stirred and reacted for 10 minutes.

[0158] B. Place the reactor in a 40°C constant temperature water bath, slowly add 1g Ti3AlC2, and stir for 48h;

[0159] C. Wash repeatedly with 1 mol / L hydrochloric acid and ultrapure water (wash three times with hydrochloric acid, then wash multiple times with ultrapure water) until the supernatant turns black. Sonicate the product (including the black supernatant) and centrifuge to obtain the etched MXene aqueous solution. Prepare a 20 mg / mL solution. -1 Ti3C2T x Dispersion.

[0160] (2) A certain mass of 8-HQ monomer was weighed and ultrasonically dispersed in anhydrous ethanol to obtain 40 mg / mL. -1 8-HQ monomer solution.

[0161] (3) Weigh a certain mass of PVA and disperse it in ultrapure water. First, stir in a water bath at 60℃ for one hour to allow the PVA particles to fully swell. Then, stir in a water bath at 90℃ for 2 hours until completely dissolved into a transparent solution, yielding 50 mg / mL of PVA. -1 PVA aqueous solution.

[0162] (4) Under ice bath sonication, 1 mL of 20 mg mL of the solution was added. -1 Ti3C2T x The dispersion was added to a small cylindrical flask containing 0.2 mL of PVA solution and sonicated for 1 hour to homogenize the system, resulting in a mixed solution.

[0163] (5) Under ice bath sonication, add the mixed solution obtained after step (4) to a solution containing 1 mL of 40 mg / mL solution. -1 In 8-HQ solution, sonicate for 30 seconds.

[0164] (6) Seal the small cylindrical bottle and transfer it into a 20°C constant temperature water bath. Let it stand for 12 hours to allow it to react fully.

[0165] (7) Wash the obtained hydrogel alternately with 5% ethanol and ultrapure water to remove unreacted impurities.

[0166] (8) The cleaned hydrogel was placed in a vacuum freeze dryer at -80℃ and frozen for 6 hours. Then, the vacuum mode of the vacuum freeze dryer was turned on to start supercritical freeze drying for 24 hours. The MXene-based composite aerogel material with adsorbed gallium ions (abbreviated as 10PM-HQ) was obtained.

[0167] Take a 100mL Erlenmeyer flask and add 50mL of a solution with a concentration of 50mg / L. -1 A gallium ion solution (pH = 3) was prepared by adding 5 mg of 10 PM-HQ (the comparative example) to an Erlenmeyer flask; the solution was then subjected to an oscillation at 25 °C and a shaking frequency of 200 rpm. -1 Adsorbed in a shaker for 24 hours.

[0168] Experimental results show that: the 10PM-HQ in this comparative example, at a concentration of 50 mg / L... -1 The adsorption capacity of gallium ions in the gallium ion solution was 104.99 mg g. -1 .

[0169] The only difference between this comparative example and Comparative Example 2 is the amount of PVA used; all other aspects are the same as in Comparative Example 2. PVA is the main component for forming the physical cross-linked structure of the material. An appropriate amount of PVA can ensure the material's adsorption capacity while giving it a more stable structure. In this comparative example, the amount of PVA is increased, occupying more of the Ti3C2T... x The active sites reduce the amount of gallium adsorbed by the prepared 10PM-HQ, resulting in a significant decrease in adsorption performance.

[0170] Experimental Example

[0171] 1. Adsorption kinetics test: MPHG-40 from Example 1 and MPHG-20 from Example 2 were used as adsorbents for the test.

[0172] The test method is as follows: Take 100 mL of an Erlenmeyer flask, add 50 mL of a gallium ion solution with a concentration of 50 mg / L (pH = 3), and then add 5 mg of adsorbent material. The test is conducted at 25℃ with an oscillation frequency of 200 rpm. -1 The effect of different contact times on adsorption performance was determined in a shaker for 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h, and 24 h.

[0173] Experimental results (kinetic adsorption curves) are as follows: Figure 3 and Figure 4 As shown.

[0174] The kinetic adsorption fitting parameters for MPHG-20 and MPHG-40 are shown in Table 1 below:

[0175] Table 1. Kinetic adsorption fitting parameters for MPHG-20 and MPHG-40

[0176]

[0177] Experimental results show that MPHG-20 aerogel exhibits a high adsorption rate in the first 2 hours, followed by a gradual decrease in adsorption rate, showing a tendency towards adsorption saturation only after 4 hours (the adsorption equilibrium time for MPHG-20 aerogel is 10 hours); MPHG-40 aerogel shows an extremely high adsorption rate in the first hour and also tends to reach adsorption saturation (the adsorption equilibrium time for MPHG-40 aerogel is 6 hours). Table 1 shows that when MPHG-20 and MPHG-40 are used as adsorbents, the experimental adsorption amounts are closer to the theoretical adsorption amounts of the pseudo-second-order kinetic model, and the correlation coefficients of both pseudo-second-order kinetics are greater than those of the pseudo-first-order kinetic model. This indicates that the pseudo-second-order kinetic model can better fit the experimental results of both models. Therefore, the adsorption of gallium ions on the surfaces of MPHG-20 and MPHG-40 materials is chemisorption.

[0178] 2. Isothermal adsorption experiment: MPHG-40 from Example 1 and MPHG-20 from Example 2 were used as adsorbents for testing.

[0179] Test method: Take 100 mL of conical flask, add 5 mg of adsorbent material, and then add 50 mL of each of the following concentration gradients: 20 mg / L. -1 40mg L -1 60mg L -1 80mg L -1 100mg L -1 120mg L -1 A gallium ion solution (pH = 3) was prepared. The solution was subjected to an oscillation at 25°C and a frequency of 200 rpm. -1 The gallium ions were adsorbed in a shaker for 24 hours. The effect of different initial gallium ion concentrations on the adsorption performance was determined.

[0180] Test results (isothermal adsorption curves) are as follows: Figure 5 and Figure 6 As shown.

[0181] The isoadsorption fitting parameters for MPHG-20 and MPHG-40 are shown in Table 2 below:

[0182] Table 2. Isoadsorption fitting parameters for MPHG-20 and MPHG-40

[0183]

[0184] Among them, Q of MPHG-40 corresponding to Example 1 in Table 2 e The value is the fitted value, and the actual measured Q is... e The value is 132.49 mgg -1 .

[0185] Experimental results show that the adsorption capacity of MPHG-20 and MPHG-40 for gallium ions increases with the increase of the initial concentration of the gallium ion solution. Table 2 shows that the correlation coefficients of the Freundlich model for MPHG-20 and MPHG-40 aerogels are closer to 1 than those for the Langmuir model, indicating that the non-uniform surface adsorption described by the Langmuir model can better describe the adsorption behavior of MPHG-20 and MPHG-40 aerogels for gallium ions.

[0186] 3. Effect of solution pH on adsorption performance: MPHG-40 from Example 1 and MPHG-20 from Example 2 were used as adsorption materials for testing.

[0187] Test method: Take 100mL of conical flask and add 50mL of a solution with a concentration of 50mg / L. -1 A gallium ion solution was prepared, and the pH gradient of the solution in the conical flask was adjusted to 1, 2, 3. 5 mg of adsorbent material was added, and the mixture was stirred at 25°C at a frequency of 200 rpm. -1 The adsorption was performed in a shaker for 24 hours, and the effect of different pH values ​​on the adsorption performance was determined.

[0188] Experimental results are as follows Figure 7 As shown.

[0189] Experimental results show that both MPHG-20 and MPHG-40 aerogels exhibit good adhesion to Ga at pH=3. 3+ The maximum adsorption capacity was 101.24 mg g. -1 and 132.49 mg g -1 .

[0190] 4. Cyclic regeneration performance test: MPHG-40 of Example 1, M-40HQ of Comparative Example 1 and 5PM-HQ of Comparative Example 2 were used as adsorbent materials for testing.

[0191] Test method: The adsorbed material is treated with 1 mol L... -1 Wash with hydrochloric acid solution to desorb, then wash with ultrapure water until neutral. After drying, weigh the sample and repeat the adsorption experiment (for pH=3, concentration 50 mg / L). -1 Adsorption was performed using a 50 mL gallium ion solution at 25 °C and an oscillation frequency of 200 rpm. -1 (Adsorbed in a shaker for 24 hours). Test the repeatability of the material.

[0192] Experimental results are as follows Figure 8 , Figure 9 , Figure 10 and Figure 11 As shown.

[0193] Experimental results show that MPHG-40 in Example 1 maintained over 95.64% of its initial adsorption capacity after 5 cycles. M-40HQ in Comparative Example 1 maintained 93.4% of its initial adsorption capacity after 5 cycles. 5PM-HQ in Comparative Example 2 maintained 87.24% of its initial adsorption capacity after 5 cycles. However, both M-40HQ and 5PM-HQ showed varying degrees of structural breakage after 5 cycles, failing to maintain their integrity. M-40HQ showed more severe structural breakage. In contrast, MPHG-40 remained largely intact after 5 cycles, exhibiting better mechanical properties compared to M-40HQ and 5PM-HQ. This is because the forces maintaining the aerogel morphology of M-40HQ are only 8-HQ and Ti3C2T. x The hydrogen bonding and electrostatic attraction between the PVA and PVA in the 5PM-HQ material create a physical cross-linked network, greatly improving the material's mechanical properties. The MPHG-40 material, building upon these two, further enhances its mechanical properties by forming a chemical cross-linked network with glutaraldehyde, resulting in excellent structural stability and superior cycling performance.

[0194] 5. X-ray photoelectron spectroscopy detection

[0195] X-ray photoelectron spectroscopy was performed on MPHG-40 of Example 1, 5PM-HQ of Comparative Example 2, and M-40HQ of Comparative Example 1 before and after gallium ion adsorption to verify whether gallium ions were successfully adsorbed on the materials.

[0196] The XPS spectrum of the test results is as follows Figure 12 As shown.

[0197] XPS Analysis: From Figure 12 It can be seen that after contact with gallium ion solution, Ga 2p atoms appeared in the XPS full spectrum of the aerogels of the three different materials. 1 / 2 Ga 2p 3 / 2 The characteristic peaks of the Ga 3d orbitals, with corresponding binding energies of 1145.46, 1118.69, and 20.53 eV, indicate that gallium ions were successfully adsorbed onto the three adsorbents.

[0198] 6. Microstructure characterization

[0199] MPHG-40 and MPHG-20 from Examples 1 and 2 were characterized by FESEM to determine their respective microstructures.

[0200] Microscopic images of MPHG-40 and MPHG-20, such as Figure 13 As shown.

[0201] from Figure 13 As can be seen, both MPHG-40 and MPHG-20 have similar porous structures in their aerogel portions, increasing the specific surface area and exposing more active sites, which is beneficial for improving adsorption performance. Meanwhile, the images of MPHG-20 show partially stacked sheet-like structures, indicating that the material cannot be fully cross-linked at low temperatures. In contrast, the fully cross-linked MPHG-40 exhibits higher adsorption performance and a more stable structure.

[0202] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., 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 preparing an MXene-based composite aerogel material that adsorbs gallium ions, characterized in that, Includes the following steps: (1) Ti3C2T under ice bath sonication x The dispersion was added to a container containing PVA solution and sonicated to homogenize the system, resulting in a mixed solution. (2) Add the mixed solution obtained in step (1) to the 8-HQ monomer solution under ice bath sonication for 30-60 s, then transfer the container to a constant temperature water bath at 20-25 ℃ and let it stand for 1-1.5 h. (3) Under ice bath sonication, chemical crosslinking agent and catalyst are added to the container in sequence, and after sonication, the container is transferred to a constant temperature water bath for reaction to obtain hydrogel; (4) Wash the hydrogel obtained after step (3) to remove unreacted impurities; (5) Freeze-drying to obtain the MXene-based composite aerogel material with adsorbed gallium ions; The concentration of 8-HQ monomer in the 8-HQ monomer solution is 20-40 mg / mL. -1 The mass ratio of PVA to 8-HQ monomer is 0.125:1; In step (3), the chemical crosslinking agent is glutaraldehyde and the catalyst is H3PO2.

2. The method for preparing the MXene-based composite aerogel material with adsorbed gallium ions according to claim 1, characterized in that, The Ti3C2T x The dispersion was prepared by a method comprising the following steps: A. Add LiF to a polytetrafluoroethylene reactor containing hydrochloric acid and stir to react; B. Place the polytetrafluoroethylene reactor treated in step A into a constant temperature water bath, slowly add Ti3AlC2, and stir to react; C. Centrifuge the reaction solution obtained in step B. Add hydrochloric acid to the centrifuged solid for washing, then add water and wash repeatedly until the supernatant turns black. After sonication, centrifuge to collect the upper liquid to obtain Ti3C2T. x Dispersion.

3. The method for preparing the MXene-based composite aerogel material with adsorbed gallium ions according to claim 2, characterized in that, In step A, the concentration of hydrochloric acid is 12 mol L. -1 The stirring reaction time is 10 min; In step B, the temperature of the constant temperature water bath is 40℃, the stirring reaction time is 48 h, and the mass ratio of hydrochloric acid, LiF and Ti3AlC2 is 7.2:1.6:

1. In step C, the hydrochloric acid washing is performed three times, and the concentration of the hydrochloric acid is 1 mol / L. -1 .

4. The method for preparing the MXene-based composite aerogel material with adsorbed gallium ions according to claim 1, characterized in that, The Ti3C2T x The volume ratio of the dispersion to the 8-HQ monomer solution is 1:2, and the Ti3C2T x Ti3C2T in dispersion x The concentration is 20 mg / mL -1 .

5. The method for preparing the MXene-based composite aerogel material with adsorbed gallium ions according to any one of claims 1-4, characterized in that, The volume ratio of glutaraldehyde to H3PO2 is 1:1; the mass-to-volume ratio of 8-HQ monomer to H3PO2 is 2:1, the mass of 8-HQ monomer is expressed in mg, and the volume of H3PO2 is expressed in μL.

6. The method for preparing the MXene-based composite aerogel material with adsorbed gallium ions according to claim 1, characterized in that, In step (3), the temperature of the water in the constant temperature water bath is 20-40 ℃, and the reaction time is 12-15 h.

7. The method for preparing the MXene-based composite aerogel material with adsorbed gallium ions according to claim 1, characterized in that, The freeze-drying process specifically involves placing the hydrogel obtained in step (4) into a vacuum freeze dryer at -80°C, freezing it for 6 hours, and then turning on the vacuum mode of the freeze dryer for 24 hours.

8. The method for preparing the MXene-based composite aerogel material with adsorbed gallium ions according to claim 1, characterized in that, In step (4), the hydrogel obtained after step (3) is washed with 5% ethanol and ultrapure water alternately.

9. An MXene-based composite aerogel material for adsorbing gallium ions, characterized in that, The MXene-based composite aerogel material with adsorbed gallium ions is prepared by the method described in any one of claims 1-8.

10. The application of the MXene-based composite aerogel material for adsorbing gallium ions according to claim 9 in the adsorption of gallium ions in fly ash acid leaching solution.

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