An aerogel composite material, its preparation method and application

Abstract

This invention provides an aerogel composite material, its preparation method, and its applications. The aerogel composite material comprises a silica aerogel substrate and a metal-organic framework material present in the silica aerogel substrate. The aerogel composite material provided by this invention has a high adsorption capacity for heavy metal ions and is recyclable.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, and particularly relates to an aerogel composite material, its preparation method, and its application. Background Technology

[0002] Heavy metal ion wastewater mainly originates from industrial production processes such as metallurgy, electroplating, and chemical processing, and contains copper (Cu). 2+ ), Zinc (Zn) 2+ ), nickel (Ni 2+ ), chromium (Cr) 6+ ), cadmium (Cd 2+ Heavy metal ions are among the most serious pollutants posing a threat to the ecological environment and human health. Unlike biodegradable organic pollutants, heavy metal ions are difficult to purify naturally and can only be treated by relocating them or altering their physicochemical forms. Therefore, developing efficient, harmless technologies that enable the recycling and reuse of heavy metal resources is of paramount importance.

[0003] Among numerous treatment methods, adsorption has attracted much attention due to its simplicity, low cost, and effective recovery of heavy metals. An ideal adsorbent should possess high adsorption capacity, excellent selectivity, and good regeneration performance. Aerogels, as nanoporous solid materials with ultra-low density, extremely high porosity, and ultra-large specific surface area, offer abundant binding sites and rapid mass transfer channels for pollutants through their unique three-dimensional network structure, and are theoretically considered highly promising and efficient adsorbents.

[0004] However, traditional aerogels (such as typical silica aerogels) have limited adsorption capacity for target ions when practically applied to the treatment of heavy metal ion wastewater, and their removal rates are insufficient to meet high-standard treatment requirements. Therefore, developing a novel adsorbent material with high adsorption capacity has become a critical issue that urgently needs to be addressed. Summary of the Invention

[0005] The main objective of this invention is to provide an aerogel composite material with a high adsorption capacity for heavy metal ions.

[0006] The present invention also provides a method for preparing an aerogel composite material, which can prepare the above-mentioned aerogel composite material, and the process is simple and low in cost.

[0007] The present invention also provides a method for treating heavy metal ion wastewater. By using the above-mentioned aerogel composite material to adsorb heavy metal ion wastewater, the adsorption capacity for heavy metal ions can be improved.

[0008] In a first aspect, the present invention provides an aerogel composite material, comprising a silica aerogel substrate and a metal-organic framework material present in the silica aerogel substrate.

[0009] The aerogel composite material as described above further includes at least one of sulfonic acid groups, amino groups, and carboxyl groups.

[0010] Secondly, the present invention provides a method for preparing the aerogel composite material as described above, comprising the following steps:

[0011] 1) A system comprising a metal-organic framework material and a silicon hydrolysate is subjected to a polycondensation reaction and a cross-linking reaction to obtain a first intermediate;

[0012] 2) The first intermediate is subjected to hydrophobic modification treatment and aging treatment in sequence to obtain the aerogel composite material.

[0013] According to the preparation method described above, the metal-organic framework material is prepared by microwave reaction;

[0014] The microwave reaction is carried out at a temperature of 120~160℃ for 5~15 minutes and at a power of 500~1000W.

[0015] In the preparation method described above, the silicon hydrolysate includes amino and carboxyl groups;

[0016] The silicon hydrolysate is treated with ethylenediamine to introduce the amino group;

[0017] And / or, the silicon hydrolysate is treated with citric acid to introduce the carboxyl group.

[0018] In the preparation method described above, the crosslinking agent used in the crosslinking reaction includes polyacrylamide;

[0019] And / or, the hydrophobic modifier used in the hydrophobic modification treatment includes sodium diethyldithiocarbamate.

[0020] The preparation method described above further includes a drying process after the aging treatment, wherein the drying process employs a supercritical drying method.

[0021] The drying medium includes ethanol, the drying pressure is 7.0~9.0 MPa, and the drying temperature is 245~280℃.

[0022] The preparation method described above further includes: subjecting the metal-organic framework material to a first sulfonation treatment to obtain the metal-organic framework material modified with sulfonic acid groups;

[0023] The first sulfonating agent used in the first sulfonation treatment includes chlorosulfonic acid, the concentration of which is 0.05~0.5mol / L, the molar ratio of the first sulfonating agent to the metal-organic framework material is (1~3):1, the temperature of the first sulfonation treatment is 0~30℃, the time is 0.5~6h, and the pH value is 5~6.

[0024] The preparation method described above further includes: subjecting the aerogel composite material to a second sulfonation treatment;

[0025] The second sulfonation treatment is carried out under an inert atmosphere. The second sulfonation reagent used in the second sulfonation treatment includes at least one of trifluoromethanesulfonic acid, sodium bisulfite, and potassium persulfate. The temperature of the second sulfonation treatment is 30~50℃, and the time is 2~6h.

[0026] Thirdly, the present invention provides a method for treating heavy metal ion wastewater, which uses the aerogel composite material as described above or the aerogel composite material prepared by the preparation method as described above to adsorb and treat the heavy metal ion wastewater.

[0027] The aerogel composite material provided by the present invention includes silica aerogel and metal-organic framework material, which combines the high specific surface area and porosity of metal-organic framework material with the lightweight and high stability of silica aerogel, thereby improving the adsorption capacity for heavy metal ions. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] Heavy metal ion wastewater mainly originates from industrial production processes such as metallurgy, electroplating, and chemical processing, and contains copper (Cu). 2+ ), Zinc (Zn) 2+ ), nickel (Ni 2+ ), chromium (Cr) 6+ ), cadmium (Cd 2+ Heavy metal ions are among the most serious pollutants posing a threat to the ecological environment and human health. Unlike biodegradable organic pollutants, heavy metal ions are difficult to purify naturally and can only be treated by relocating them or altering their physicochemical forms. Therefore, developing efficient, harmless technologies that enable the recycling and reuse of heavy metal resources is of paramount importance.

[0030] Currently, common methods for treating heavy metal ion wastewater include chemical precipitation, coagulation / flocculation, ion exchange, membrane separation, electrochemical methods, and adsorption. Among these, adsorption is widely recognized as one of the most promising technologies due to its relatively low cost, ease of operation, good treatment effect, and potential for resource recovery. However, existing adsorption materials, such as activated carbon, ion exchange resins, zeolites, clay minerals, and metal oxides, all have significant limitations in practical applications. These materials may suffer from limited adsorption capacity and poor selectivity, high preparation costs and regeneration difficulties, or even the potential to cause secondary pollution during use, severely restricting their large-scale application in industrial wastewater treatment.

[0031] Aerogels, as nanoporous solid materials with ultra-low density, extremely high porosity, and ultra-large specific surface area, are considered promising and highly efficient adsorbents. However, traditional aerogels (such as silica aerogels) have limited adsorption capacity for target ions, and their removal rates are insufficient to meet high-standard treatment requirements, severely limiting their practical application in the treatment of heavy metal ion wastewater.

[0032] The inventors of this application have discovered through research that combining silica aerogel with metal-organic framework materials can significantly improve the adsorption capacity for heavy metal ions.

[0033] In a first aspect, the present invention provides an aerogel composite material, comprising a silica aerogel substrate and a metal-organic framework material present in the silica aerogel substrate.

[0034] The aerogel composite material provided by this invention comprises silica aerogel and a metal-organic framework (MOF) material, which can improve the adsorption capacity for heavy metal ions. This is because the composite material combines the high specific surface area and porosity of MOF materials with the lightweight and high stability of silica aerogel. Due to its high specific surface area and porosity, the MOF material provides abundant adsorption sites, enhancing the adsorption capacity for heavy metal ions. Silica aerogel, as a substrate material, supports the MOF material and forms a stable three-dimensional network structure, providing more adsorption sites. Furthermore, the nanoscale support framework forms uniform channels, enhancing mass transfer efficiency and increasing the adsorption capacity of the composite material.

[0035] Therefore, the aerogel composite material provided by the present invention, comprising silica aerogel and metal-organic framework material, can improve the adsorption capacity for heavy metal ions.

[0036] In some embodiments of the present invention, the aerogel composite material further includes at least one of sulfonic acid group, amino group, and carboxyl group.

[0037] The aerogel composite material provided by this invention is modified with at least one of sulfonic acid groups, amino groups, and carboxyl groups on the surface and within the pores of the material. The strong interaction between the sulfonic acid groups and heavy metal ions can enhance the adsorption capacity of the aerogel composite material. Hydrophilic functional groups, such as amino and carboxyl groups, can improve the adsorption capacity of the composite material's active sites for heavy metal ions, especially Pb. 2+ and Hg 2+ .

[0038] Secondly, the present invention provides a method for preparing the aerogel composite material as described above, comprising the following steps:

[0039] 1) A system comprising a metal-organic framework material and a silicon hydrolysate is subjected to a polycondensation reaction and a cross-linking reaction to obtain a first intermediate;

[0040] 2) The first intermediate was subjected to hydrophobic modification and aging treatment in sequence to obtain an aerogel composite material.

[0041] Specifically, in step 1), the metal-organic framework material and the silicon hydrolysate are mixed and subjected to a polycondensation reaction. Then, a crosslinking agent is added to form a three-dimensional crosslinked network structure to obtain the first intermediate, which enhances the interfacial bonding strength between the metal-organic framework material and the silica aerogel, forming a stable skeleton structure. This avoids the aggregation and loss of the metal-organic framework material and significantly improves the mechanical and hydrothermal stability of the material.

[0042] In step 2), a hydrophobic modifier is added to the first intermediate, and a stirring reaction is carried out to perform a surface hydrophobic modification treatment on the first intermediate to improve the material's resistance to swelling, thereby solving the problem of easy degradation or swelling of aerogel materials in aqueous environments. Subsequently, an aging treatment is performed, for example, by immersing the wet gel in a mixed solution containing silicon hydrolysate and ethanol at 40~80℃ and allowing it to stand for 24~72 hours to obtain the aerogel composite material. The aging treatment can enhance the mechanical strength of the material.

[0043] The method for preparing aerogel composite material provided by the present invention can prepare the above-mentioned aerogel composite material, and the aerogel composite material can improve the adsorption capacity of heavy metal ions and can also be recycled.

[0044] In some embodiments of the present invention, the metal-organic framework material is prepared by microwave reaction; the temperature of the microwave reaction is 120~160℃, for example, it can be a range of 120℃, 130℃, 140℃, 150℃, 160℃ or any two of these; the time is 5~15min, for example, it can be a range of 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min or any two of these; the power is 500~1000W, for example, it can be a range of 500W, 600W, 700W, 800W, 900W, 1000W or any two of these.

[0045] The metal-organic framework material of the present invention is prepared by microwave reaction, and the temperature, time and power of the microwave reaction are within the above range, which can rapidly synthesize the metal-organic framework material, shorten the reaction time and improve the yield.

[0046] Taking ZIF-8 metal-organic framework material as an example, it can be prepared through the following steps:

[0047] ZIF-8 nanoparticles were synthesized by microwave-assisted synthesis of zinc salt and 2-methylimidazole dissolved in an alcohol solvent.

[0048] This method promotes the coordination reaction between zinc ions and 2-methylimidazole through rapid pyrolysis, forming ZIF-8 nanoparticles with uniform particle size. Compared with the traditional hydrothermal method, it shortens the reaction time and improves the crystallinity.

[0049] In some embodiments of the present invention, the silicon hydrolysate includes amino and carboxyl groups.

[0050] The silicon hydrolysate was treated with ethylenediamine to introduce amino groups.

[0051] In some embodiments, citric acid is used to treat the silicon hydrolysate to introduce carboxyl groups.

[0052] In this invention, ethylenediamine, as a polyamine compound, undergoes a condensation reaction between its -NH2 group and the Si-OH group in the silicon hydrolysate to form a -Si-NH- crosslinked structure. Meanwhile, the -COOH group of citric acid interacts with metal-organic framework materials (such as the imidazole ring on the surface of ZIF-8) through hydrogen bonds. The synergistic effect of these two factors enhances the mechanical strength of the aerogel composite material.

[0053] In this invention, the silicon hydrolysate is obtained by mixing a sodium silicate solution with an acid solution (e.g., hydrochloric acid solution) and stirring under heating conditions to carry out a hydrolysis reaction. Furthermore, the silicon source used in this invention has a low cost, making it highly economical.

[0054] In some embodiments of the present invention, the crosslinking agent used in the crosslinking reaction includes polyacrylamide.

[0055] In this invention, polyacrylamide is used as a crosslinking agent. This crosslinking agent forms a hydrogen bond network with the hydroxyl groups in the silicon hydrolysate through amide groups (-CONH2), and, combined with the coordination effect of the metal-organic framework material, constructs a three-dimensional crosslinked structure, thereby improving the compressive strength of the aerogel composite material.

[0056] In some embodiments, the hydrophobic modifier used in the hydrophobic modification treatment includes sodium diethyldithiocarbamate.

[0057] Sodium diethyldithiocarbamate reacts with the hydroxyl groups on the surface of silica through the -SSN- structure to form a hydrophobic monolayer. This reduces the hydrophilicity of the material surface and minimizes the damage of water molecules to the pore structure, resulting in excellent long-term stability of the aerogel composite material in an aqueous environment.

[0058] In some embodiments of the present invention, the aging treatment is followed by a drying treatment, which employs a supercritical drying method. The drying medium includes ethanol, and the drying pressure is 7.0~9.0 MPa, for example, it can be a range of 7.0 MPa, 7.5 MPa, 8.0 MPa, 8.5 MPa, 9.0 MPa or any two thereof. The drying temperature is 245~280°C, for example, it can be a range of 245°C, 250°C, 255°C, 260°C, 270°C, 280°C or any two thereof.

[0059] In this invention, after aging treatment, an organic solvent, such as acetone, can be used to wash and replace the aged wet gel multiple times to remove excess metal ions, followed by drying treatment to obtain an aerogel composite material.

[0060] The drying process can be performed using freeze-drying and / or supercritical drying, with supercritical drying being preferred. When supercritical drying is used, the drying medium includes ethanol, and the pressure and temperature during drying are within the aforementioned ranges. This avoids damage to the pore structure caused by liquid-gas interfacial tension, maintains the integrity of the aerogel nanoporous structure, and enhances the material's resistance to swelling.

[0061] Specifically, the wet gel can be introduced into a drying vessel, and the temperature and pressure can be increased. After a residence time of 30 min to 120 min, the product can be removed by cooling and depressurization. The rate of heating or cooling is 1 to 2 °C / min, and the rate of pressurization or depressurization is 0.1 to 0.3 MPa / min.

[0062] In some embodiments of the present invention, the method further includes: subjecting the metal-organic framework material to a first sulfonation treatment to obtain a sulfonic acid-modified metal-organic framework material; the first sulfonation reagent used in the first sulfonation treatment includes chlorosulfonic acid, the concentration of which is 0.05~0.5 mol / L, for example, it can be within the range of 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, or any two thereof; the molar ratio of the first sulfonation reagent to the metal-organic framework material is (1~3):1, for example, it can be... The ratio is 1:1, 1.5:1, 2:1, 2.5:1, 3:1, or any two of these; the temperature of the first sulfonation treatment is 0~30℃, for example, it can be 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, or any two of these; the time is 0.5~6h, for example, it can be 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, or any two of these; the pH value is 5~6, for example, it can be 5, 5.1, 5.3, 5.5, 5.7, 5.9, 6, or any two of these.

[0063] The concentration of chlorosulfonic acid and the conditions of the first sulfonation treatment mentioned above can ensure that the sulfonic acid group modification is relatively thorough and can also avoid the agglomeration of metal-organic framework materials.

[0064] Specifically, after cleaning and drying the metal-organic framework material, the metal-organic framework material is premixed with chlorosulfonic acid in an ice bath to obtain a first mixture. Then, a certain amount of chlorosulfonic acid is slowly added dropwise to the first mixture. During the first sulfonation treatment, the temperature and pH value are controlled to avoid the formation of by-products. After a certain reaction time, methanol is added to dissolve the excess acid and the mixture is filtered and dried to obtain the sulfonic acid-modified metal-organic framework material.

[0065] In some embodiments of the present invention, the method further includes: subjecting the aerogel composite material to a second sulfonation treatment; the second sulfonation treatment is carried out under an inert atmosphere, and the second sulfonation reagent used in the second sulfonation treatment includes at least one of trifluoromethanesulfonic acid, sodium bisulfite, and potassium persulfate; the temperature of the second sulfonation treatment is 30~50°C, for example, it can be a range of 30°C, 35°C, 40°C, 45°C, 50°C, or any two of these; the time is 2~6h, for example, it can be a range of 2h, 3h, 4h, 5h, 6h, or any two of these.

[0066] Specifically, the aerogel composite material can be immersed in a second sulfonating agent for a second sulfonation treatment, further introducing sulfonic acid groups. After the reaction, neutralization (e.g., using NaHCO3 solution), washing with water (e.g., washing with deionized water until neutral), and finally drying (e.g., freeze-drying) are performed to obtain the sulfonic acid-modified aerogel composite material.

[0067] A second sulfonation treatment further introduces sulfonic acid groups, increasing the number of adsorption sites. Performing the second sulfonation treatment under an inert atmosphere ensures its smooth progress and avoids the formation of byproducts. Furthermore, the strong sulfonation ability of trifluoromethanesulfonic acid, along with the appropriate temperature and time for the second sulfonation treatment, further ensures its thorough completion. In addition, the reversible coordination ability of the sulfonic acid groups allows the aerogel composite material to maintain a strong adsorption capacity for heavy metal ions after regeneration, meaning the aerogel composite material is recyclable.

[0068] Thirdly, the present invention provides a method for treating heavy metal ion wastewater, which uses the aerogel composite material as described above or the aerogel composite material prepared by the preparation method as described above to adsorb and treat the heavy metal ion wastewater.

[0069] In the specific treatment process, the aerogel composite material can be immobilized in the adsorption bed, and the heavy metal ion wastewater can be passed through the adsorption bed, thereby allowing the heavy metal ions in the wastewater to be adsorbed by the aerogel composite material. Using this aerogel composite material to treat heavy metal ion wastewater can significantly improve the removal rate of heavy metal ions.

[0070] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0071] Example 1

[0072] The preparation method of the aerogel composite material in this embodiment includes the following steps:

[0073] 1) Dissolve 1.0 g of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and 7.7 g of 2-methylimidazole (2-MeIM) in 100 mL of methanol solution to form clear solutions A and B, respectively. Then, place solutions A and B in a microwave reactor and react at 140 °C and 800 W for 10 min to allow metal ions to coordinate with imidazole ligands to form ZIF-8 nanoparticles. Next, centrifuge at 8000 r / min for 15 min to separate the white precipitate. Wash the precipitate repeatedly with methanol solution and deionized water, repeating the washing process 4 times to fully remove residual solvent and unreacted substances. Dry the precipitate under vacuum at 60 °C for 10 h to obtain white powdered ZIF-8 nanoparticles. First, ZIF-8 nanoparticles were premixed with 0.2 mol / L chlorosulfonic acid in an ice bath to obtain a first mixture. Then, 0.2 mol / L chlorosulfonic acid was slowly added dropwise to the first mixture at room temperature (approximately 25°C) to obtain a second mixture. The molar ratio of chlorosulfonic acid to ZIF-8 nanoparticles in the second mixture was 1.5:1 to ensure complete first sulfonation. During the first sulfonation process, the temperature was controlled at 25°C and the pH at 6 to avoid the formation of byproducts. After a 5-hour reaction, methanol was added to dissolve excess acid, and the mixture was filtered to obtain a precipitate. Subsequently, the precipitate was dried in a vacuum oven at 40°C for 6 hours to obtain the sulfonated product, which is the sulfonic acid-modified ZIF-8 nanoparticles.

[0074] 2) Take 500g of sodium silicate solution with a mass fraction of 30% and mix it with hydrochloric acid solution with a concentration of 0.1mol / L. Stir at 60℃ for 10h to fully hydrolyze the solution. Then, add 60mL of ethylenediamine solution and 30g of citric acid. React at 60℃ for 2h to obtain the silica hydrolysate.

[0075] 3) Add sulfonic acid-modified ZIF-8 nanoparticles to the silicon hydrolysate, mix to form a uniform dispersion system, carry out a polycondensation reaction at 80°C, and after the reaction is completed, add a small amount of polyacrylamide, stir to form a gel with a cross-linked structure, i.e., the first intermediate.

[0076] 4) A 6% sodium diethyldithiocarbamate solution was added to the first intermediate and stirred at 60°C for 6 hours to obtain a surface-hydrophobically modified first intermediate (wet gel). The wet gel was aged for 3 days. Then, acetone was added to the wet gel and the mixture was stirred and washed at 70°C for 6 hours as one wash. The washing was repeated 4 times to obtain a washed wet gel. The aerogel composite precursor was obtained by supercritical drying with ethanol at a pressure of 8.0 MPa and a temperature of 260°C.

[0077] 5) The aerogel composite precursor was immersed in trifluoromethanesulfonic acid solution and subjected to a second sulfonation treatment at 40°C for 4 hours under nitrogen protection; neutralized with saturated NaHCO3 solution and washed with deionized water until neutral. The final aerogel composite material was obtained by freeze-drying.

[0078] The aerogel composite material comprises a silica aerogel substrate and a metal-organic framework material present in the silica aerogel substrate. The aerogel composite material also includes sulfonic acid groups, amino groups, and carboxyl groups.

[0079] Example 2

[0080] The preparation method of the aerogel composite material in Example 2 is basically the same as that in Example 1, except that the first sulfonation treatment is not performed in step 1).

[0081] Example 3

[0082] The preparation method of the aerogel composite material in Example 3 is basically the same as that in Example 1, except that in step 2), ethylenediamine solution is not added, that is, the aerogel composite material does not contain amino groups.

[0083] Example 4

[0084] The preparation method of the aerogel composite material in Example 4 is basically the same as that in Example 1, except that citric acid is not added in step 2), that is, the aerogel composite material does not contain carboxyl groups.

[0085] Example 5

[0086] Example 5 uses an aerogel composite material that has been regenerated 5 times, wherein the regeneration of the aerogel composite material is achieved by disodium ethylenediaminetetraacetate.

[0087] Comparative Example 1

[0088] Comparative Example 1 used silica aerogel.

[0089] Experimental example:

[0090] The Cu in the original heavy metal ion wastewater used in this experiment 2+ Pb 2+ Hg 2+ Cr 6+ Cd 2+ The concentrations were 55 mg / L, 68 mg / L, 49 mg / L, 36 mg / L, and 41 mg / L, respectively.

[0091] The aerogel composite material used in the above embodiments and comparative examples is used to treat heavy metal ion wastewater, specifically including:

[0092] 10g of the aerogel composite material from the above examples and comparative examples was fixed in an adsorption bed, and the heavy metal ion wastewater was allowed to flow through the adsorption bed at a rate of 50mL / min, so that the heavy metal ions therein were adsorbed by the aerogel composite material.

[0093] The concentration of heavy metal ions in the wastewater after adsorption treatment was determined by atomic spectrophotometer. The heavy metal ion removal rate was calculated as follows: (concentration of heavy metal ions before adsorption treatment - concentration of heavy metal ions after adsorption treatment) / concentration of heavy metal ions before adsorption treatment × 100%. The specific test results are shown in Table 1.

[0094] Table 1 Removal rates of different heavy metal ions

[0095]

[0096] As shown in Table 1, compared with the comparative example, the aerogel composite material provided by the present invention, including silica aerogel and metal-organic framework material, can improve the adsorption capacity for heavy metal ions, especially Cu. 2+ Pb 2+ and Hg 2+ .

[0097] As can be seen from Example 5, the aerogel composite material provided by the present invention can be regenerated and recycled multiple times. After regeneration 5 times, its removal rate of heavy metal ions still remains at a high level.

[0098] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to what has been described above. Various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method of making an aerogel composite material, characterized by, The method comprises the following steps: 1) the metal-organic framework material prepared by the microwave reaction is subjected to a first sulfonation treatment to obtain a sulfonic acid group modified metal-organic framework material, the modified metal-organic framework material is added into a silicon hydrolyzate to perform a polycondensation reaction and a crosslinking reaction, and a first intermediate is obtained; the silicon hydrolyzate comprises amino groups and carboxyl groups; 2) the first intermediate is sequentially subjected to a hydrophobic modification treatment, an aging treatment, and a second sulfonation treatment to obtain the aerogel composite material.

2. The preparation method according to claim 1, wherein the microwave reaction is performed at a temperature of 120-160℃ for 5-15 min at a power of 500-1000 W.

3. The preparation method according to claim 1, wherein the silicon hydrolyzate is treated with ethylenediamine to introduce the amino groups; and / or the silicon hydrolyzate is treated with citric acid to introduce the carboxyl groups. The crosslinking agent used in the crosslinking reaction comprises polyacrylamide; and / or the hydrophobic modifier used in the hydrophobic modification treatment comprises sodium diethyl dithiocarbamate. The aging treatment is further followed by a drying treatment, and the drying treatment is performed by using a supercritical drying method; 4. The method of claim 1, wherein, the drying treatment is performed in a medium comprising ethanol at a pressure of 7.0-9.0 MPa and at a temperature of 245-280℃.

6. The preparation method according to claim 1, wherein the first sulfonation reagent used in the first sulfonation treatment comprises chlorosulfonic acid, the concentration of the chlorosulfonic acid is 0.05-0.5 mol / L, the molar ratio of the first sulfonation reagent to the metal-organic framework material is (1-3):1, the temperature of the first sulfonation treatment is 0-30℃, the time of the first sulfonation treatment is 0.5-6 h, and the pH value of the first sulfonation treatment is 5-6.

5. The preparation method according to claim 1, characterized in that, 7. The preparation method according to any one of claims 1-6, wherein the second sulfonation treatment is performed under the protection of an inert atmosphere, the second sulfonation reagent used in the second sulfonation treatment comprises at least one of triflic acid, sodium bisulfite, and potassium persulfate, the temperature of the second sulfonation treatment is 30-50℃, and the time of the second sulfonation treatment is 2-6 h. The aerogel composite material comprises a silica aerogel substrate and a metal-organic framework material present in the silica aerogel substrate; and the aerogel composite material is prepared by using the preparation method according to any one of claims 1-7. The aerogel composite material further comprises at least one of sulfonic acid groups, amino groups, and carboxyl groups. The aerogel composite material according to claim 8 or 9 or prepared by using the preparation method according to any one of claims 1-7 is used to perform an adsorption treatment on heavy metal ion wastewater. ​ ​ 8. An aerogel composite material, characterized by, ​ 9. The aerogel composite of claim 8, wherein, ​ 10. A method for treating heavy metal ion waste water, characterized by, ​

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