Aerogels based on protein fiber composite oligolayers MXene, methods and applications

Abstract

This invention discloses a method for preparing a protein fiber composite oligolayer MXene aerogel, comprising: fiberizing a 2-8 wt.% pea protein suspension to obtain a starch protein fiber suspension; preparing a 5 mg / mL-10 mg / mL MXene suspension; depositing starch protein fibers in situ onto the MXene surface using an electrostatic adsorption strategy to obtain a precursor mixture; and performing directional cryo-casting and gas-phase crosslinking on the precursor mixture to obtain the aerogel material. This method, on the one hand, utilizes electrostatic adsorption deposition to composite pea protein fibers with oligolayer MXene, improving the stability of the photothermal MXene layer; on the other hand, the porous aerogel produced by directional cryo-casting possesses a directional vertical pore structure. This structure not only improves its salt resistance but also enhances its photothermal conversion efficiency and solar evaporation rate, reducing operating and maintenance costs. Therefore, the aerogel of this invention has potential applications in the preparation of highly efficient photothermal evaporation synergistic marine uranium extraction materials.

Description

Technical Field

[0001] This invention relates to the fields of interfacial evaporation water treatment and heavy metal adsorption technology, and particularly to an aerogel based on protein fiber composite oligolayer MXene, its method, and its application. Background Technology

[0002] Seawater desalination is a feasible way to obtain large quantities of fresh water. However, most current seawater desalination methods use membrane distillation and reverse osmosis, which consume large amounts of fossil fuels and are detrimental to environmental sustainability. Solar interfacial evaporation is a promising freshwater production method due to its low cost and high efficiency. A solar interfacial evaporator is a device that uses solar energy to drive water evaporation. Through efficient photothermal conversion, it converts light energy into heat energy and concentrates the heat at the water-air interface, thereby maximizing evaporation efficiency. It has potential applications in seawater desalination, wastewater treatment, and salt extraction, thus attracting the interest of many researchers. For example, Chinese patent CN202311487004.2 discloses a solar interfacial evaporator based on starch-like plant protein fiber aerogel, its preparation method, and its application. Soy protein isolate powder is fiberized and SPI-AF-Gel aerogel is obtained through directional freezing and steam crosslinking strategies. Subsequently, a polypyrrole photothermal coating is grown in situ on the surface of the SPI-AF-Gel aerogel using in-situ polymerization to obtain the SPI-AF-Gel@PPy solar interfacial evaporator. Despite some progress, existing solar interfacial evaporators may have the following problems:

[0003] (1) Poor stability of photothermal materials: As the core component of solar interfacial evaporators, photothermal materials directly affect the evaporation rate and photothermal conversion efficiency of the evaporation device. For example, MXene, as a two-dimensional semiconductor photothermal material, has shown broad application prospects in the field of interfacial evaporation due to its excellent light absorption and photothermal conversion capabilities. However, in actual use, MXene is prone to oxidation in air or water environments, which leads to a decrease in its light absorption performance and thus reduces the photothermal conversion efficiency.

[0004] (2) High cost of interfacial evaporator matrix materials: Currently, most matrix materials used to prepare solar interfacial evaporators are petroleum-based polymers. With the increasing scarcity of global oil resources and stricter environmental protection requirements, oil prices are on the rise, leading to a continuous increase in the raw material costs of petroleum-based polymers. In addition, traditional petroleum-based polymers degrade during use, producing microplastics or other pollutants, which in turn cause serious damage to the environment.

[0005] (3) Insufficient long-term operating capacity of interfacial evaporators: Most aerogels are prepared using a simple freeze-drying method, resulting in a disordered porous structure. However, this disordered pore arrangement is not conducive to the effective reflux of salts in interfacial evaporation applications. During long-term evaporation, salts tend to accumulate on the evaporator surface and gradually block the pore channels. This phenomenon not only hinders water transport but also reduces light absorption efficiency, ultimately leading to a decline in the evaporator's evaporation performance and adversely affecting its long-term stable operation.

[0006] Therefore, it is necessary to develop a protein fiber composite oligolayer MXene aerogel, its preparation method, and its application to solve the above problems. Summary of the Invention

[0007] In view of this, the present invention provides a method for preparing protein fiber composite oligolayer MXene aerogel, which solves the problem of poor photothermal material coating stability in existing evaporators, resulting in poor photothermal conversion efficiency or evaporation rate.

[0008] This invention employs a method for preparing MXene aerogel based on protein fiber composite oligolayers, characterized by the following steps:

[0009] S101 Take 2-8 wt.% pea protein suspension and fibrose it to obtain starch protein fiber suspension;

[0010] S102 was used to prepare 5 mg / mL-10 mg / mL MXene suspensions;

[0011] S103 uses an electrostatic adsorption strategy to deposit starch protein fibers in situ onto the MXene surface to obtain a precursor mixture with a pH of 1-3.

[0012] S104 was used to obtain aerogel materials by directional cryogenic casting and vapor-phase crosslinking of the precursor mixture.

[0013] Preferably, PPI-AF@MXene-Gel aerogel is prepared by freeze-drying using an ice template: PPI-AF@MXene solution is poured into a custom copper ice template mold with a diameter of 3.5 cm, and directionally frozen in a liquid nitrogen environment at -196℃ for 30-60 min. Then, it is placed in a freeze dryer for 2-3 days to obtain PPI-AF@MXene aerogel. The aerogel is then crosslinked with 25% glutaraldehyde vapor in an oven at 40℃ for 4 h to obtain pea protein isolate starch cellulose-based PPI-AF@MXene-Gel aerogel.

[0014] Preferably, in step S101, pea protein isolate is dissolved in ultrapure water containing NaCl, and then the pH of the solution is adjusted to 1-3 with hydrochloric acid. After hydration at 4°C for 16 hours, the solution is centrifuged at 10,000 rpm for 20 minutes, and the insoluble substances are removed by filtration to obtain a pea protein isolate solution with a mass concentration of 2 wt.%. The solution is then stirred at 250 rpm for 16 hours in an oil bath at 85°C, cooled in an ice bath, and incubated at room temperature for 1 day to obtain a starch protein cellulose solution.

[0015] Preferably, in step S102, LiF is weighed and completely dissolved in hydrochloric acid solution to prepare an etching solution. Then, Ti3AlC2 is slowly added to the etching solution. After stirring continuously at 28°C for 24 hours, the mixture is washed until the pH of the mixture becomes 7. After the reaction is completed, the reaction product is washed multiple times to make the pH of the reaction product neutral. The product is then transferred to a clean and dry flask, purged with argon gas, sonicated in an ice bath for 2 hours, and then centrifuged for 1 hour. The supernatant is collected to obtain an MXene suspension with a concentration of 8 mg / mL.

[0016] Preferably, in step S103, 8 mL of starch protein cellulose solution and 1 mL of MXene suspension are weighed and stirred to obtain a precursor mixture.

[0017] Preferably, in step S103, the pH of the starch protein cellulose solution is 2; and the pH of the MXene suspension solution is 7.

[0018] Preferably, in step S104, directional cryogenic casting is performed by directional freezing in a liquid nitrogen environment at -196°C for 30-60 minutes, followed by placing it in a freeze dryer for 2-3 days.

[0019] Preferably, the gas-phase crosslinking in step S104 is specifically obtained by crosslinking with 25% glutaraldehyde vapor in an oven at 40°C for 4 hours.

[0020] In another aspect, the present invention provides an aerogel material based on protein fiber composite oligolayer MXene and its application in efficient photothermal evaporation synergistic marine uranium extraction.

[0021] The method for preparing MXene aerogel based on protein fiber composite oligolayers provided by this invention utilizes electrostatic adsorption deposition to composite MXene oligolayers with pea protein fibers, thereby improving the stability of the photothermal MXene layer. Furthermore, the porous aerogel, produced through directional cryogenic casting, possesses a directional vertical pore structure, which not only facilitates the directional migration and expulsion of salt, enhancing its salt resistance, but also improves its photothermal conversion efficiency (85.9%) and solar evaporation rate (2.69 kg m³). - 2 h -1 This reduces operating and maintenance costs.

[0022] Furthermore, the porous aerogel honeycomb structure of this invention has a uniform pore size distribution (80 μm-1 mm) and exhibits excellent uranium ion adsorption. The composite material of this invention can be applied in fields such as efficient and stable solar thermal conversion, clean water production, and uranium extraction, especially showing potential applications in the field of efficient photothermal evaporation combined with uranium resource extraction. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the preparation process of a protein fiber composite oligolayer MXene aerogel according to the present invention.

[0024] Figure 2 Photographs of MXene suspensions at different mass concentrations.

[0025] Figure 3 XRD patterns for MXene, PPI-AF, and PPI-AF@MXene.

[0026] Figure 4 a is a TEM image of PPI fiber morphology; 4b is a TEM image of MXene; 4c is a TEM image of PPI-AF@MXene.

[0027] Figure 5 5a is a top view of the PPI-AF@MXene-Gel using SEM; 5b is a side view of the PPI-AF@MXene-Gel using SEM.

[0028] Figure 6 The mechanical properties test results are for PPI-AF@MXene-Gel.

[0029] Figure 7 a) UV-Vis-NIR absorption spectra of PPI-AF-Gel, PPI-AF-Gel@MXene, and PPI-AF@MXene-Gel aerogels; 7b) Surface temperature distribution of PPI-AF-Gel, PPI-AF-Gel@MXene, and PPI-AF@MXene-Gel aerogels (dry state) under single-solar irradiation; 7c) Surface temperature distribution of PPI-AF-Gel, PPI-AF-Gel@MXene, and PPI-AF@MXene-Gel aerogels (wet state) under single-solar irradiation; 7d) Infrared thermograph of PPI-AF@MXene-Gel (dry state) under single-solar irradiation; 7e) Water evaporation performance of different aerogel samples under one solar intensity with pure water as a blank control; 7f) Water evaporation performance of PPI-AF@MXene-Gel at different salt concentrations; 7g) Comparison of evaporation rate and energy conversion efficiency of different aerogel generators.

[0030] Figure 8 a) shows the ion concentration of PPI-AF@MXene-Gel aerogel before and after photothermal desalination of real seawater; 8b) shows the salt degradation experiment of PPI-AF@MXene-Gel aerogel; 8c) shows the evaporation performance of PPI-AF@MXene-Gel aerogel in 3.5wt% brine under a single solar irradiation (8h each time); 8d) shows the evaporation performance of PPI-AF-Gel@MXene aerogel in 3.5wt% brine under a single solar irradiation (8h each time); 8e) compares the performance of different aerogel evaporators; 8f) shows the stability comparison between PPI-AF@MXene-Gel and PPI-AF-Gel@MXene aerogel.

[0031] Figure 9 a represents the adsorption kinetics and fitting results of uranium by PPI-AF-Gel; Figure 9 b represents the adsorption kinetics and fitting results of uranium on PPI-AF@MXene-Gel. Detailed Implementation

[0032] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0033] Example 1: As Figure 1 A method for preparing MXene aerogel based on protein fiber composite oligolayer includes the following steps:

[0034] S101 extracts pea protein isolate via alkali dissolution and acid precipitation. A starch protein cellulose (PPI-AF) solution is then prepared using a simple heat treatment followed by ice bath cooling and room temperature incubation: Pea protein isolate is dissolved in ultrapure water containing 150 mM NaCl, and the solution is adjusted to pH 2.0 with 6 M hydrochloric acid and hydrated at 4°C for 16 h. The protein solution is then centrifuged at 10,000 rpm for 20 min, and filtered through a 0.45 μm filter to remove insoluble substances, yielding a 2 wt% pea protein isolate solution. This pea protein isolate solution is stirred at 250 rpm for 16 h in an oil bath at 85°C, and immediately after heat treatment, cooled in an ice bath and incubated at room temperature for 1 day to obtain the starch protein cellulose (PPI-AF) solution.

[0035] S102 prepared an MXene suspension via wet etching: First, 1.6 g of LiF (61.5 mmol) was completely dissolved in 20 mL of 9 M HCl aqueous solution to prepare an etching solution. Then, 1 g of Ti3AlC2 was slowly added to the etching solution. After stirring continuously at 28 °C for 24 h, the mixture was washed multiple times with ultrapure water until the pH of the mixture reached 7. After the etching reaction was completed, the reaction product was washed multiple times with ultrapure water to remove residual etching solution and byproducts. During this process, continuous stirring and centrifugation were required to accelerate the washing effect. Through washing and centrifugation, the pH of the reaction product was made neutral. Then, the neutral mixture was transferred to a clean and dry flask, purged with argon three times, sonicated in an ice-water bath for 2 h, and then centrifuged at 3200 rpm for 1 h. The supernatant was collected to obtain an 8 mg / mL MXene suspension.

[0036] S103 utilizes an electrostatic in-situ adsorption strategy to prepare an aerogel precursor solution: 8 mL of starch protein cellulose suspension (PPI-AF, pH 2) prepared in step S103 and 1 mL of MXene suspension (concentration 8 mg / mL, pH 7) are weighed and mixed uniformly by magnetic stirring for 5 min to obtain the PPI-AF@MXene precursor solution. The pH of the PPI-AF@MXene precursor solution was tested to be between 1 and 3.

[0037] S104 Preparation of PPI-AF@MXene-Gel Aerogel by Freeze-drying with Ice Template: PPI-AF@MXene solution was poured into a custom copper ice template mold with a diameter of 3.5 cm, and directionally frozen in a liquid nitrogen environment at -196℃ for 30 min. Then, it was placed in a freeze dryer for 2 days to obtain PPI-AF@MXene aerogel. Crosslinking was carried out in an oven at 40℃ using 25% glutaraldehyde vapor for 4 h to obtain pea protein isolate starch cellulose-based PPI-AF@MXene-Gel aerogel.

[0038] Example 2: The difference between Example 2 and Example 1 is the effect of the concentration of the MXene suspension added in step (3) on the material properties. The concentrations of the MXene suspension were 1 mg / mL, 3 mg / mL, 5 mg / mL, 10 mg / mL, and 15 mg / mL, respectively.

[0039] Depend on Figure 2The results show that at low deposition rates (i.e., MXene concentration below 5 mg / mL), the content of photothermal material is relatively low, directly resulting in a lighter surface color. This insufficient content significantly affects the light absorption efficiency of the material. At moderate deposition rates (i.e., MXene concentration in the range of 5-10 mg / mL), MXene can form a relatively uniform and stable deposition layer in the material. At high deposition rates (i.e., MXene concentration above 10 mg / mL), MXene is prone to agglomeration during deposition. This is because as the MXene concentration increases, the interaction forces between nanosheets strengthen, making them more likely to attract each other and aggregate. This agglomeration leads to the formation of thick, layered structures from the accumulated MXene sheets, resulting in uneven distribution within the material and decreased stability. Therefore, the preferred concentration of the MXene suspension is 5-10 mg / mL.

[0040] Example 3: The difference between Example 3 and Example 1 lies in the effect of the pH of the mixed solution of starch protein fiber solution and MXene suspension added in step (3) on the material properties. In Example 1, a protein fiber solution with pH 2 and an MXene suspension with pH 7 were used to obtain an acidic mixed solution (pH 1-3). In Example 3, the protein fiber solution with pH 2 and the MXene suspension with pH 7 were mixed, and the pH was adjusted with 2M NaOH to obtain a mixed solution of neutral (pH 6-7) and alkaline (pH 9-10). As shown in Table 1, pea protein fiber exhibits good dispersibility in solutions with pH 1-3, which is conducive to its deposition on the MXene surface. However, in neutral or alkaline environments, MXene material is easily corroded and decomposed by alkaline solutions, resulting in poor structural stability; at the same time, alkaline environments may cause denaturation or precipitation of pea protein fiber, affecting the deposition effect.

[0041] Table 1. Effect of pH on material properties of MXene suspension.

[0042]

[0043] In another embodiment, the starch protein cellulose (PPI-AF) solution was obtained by fibrozing an 8 wt.% pea protein suspension (PPI).

[0044] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that in step S103, PPI-AF-Gel aerogel was prepared by freeze-drying 8 mL of fiber solution using an ice template and then crosslinking it with 25% glutaraldehyde vapor in an oven at 40°C for 4 h. Then, 1 mL of MXene solution was spin-coated onto the surface of the above PPI-AF-Gel aerogel to obtain PPI-AF-Gel@MXene aerogel.

[0045] Comparative Example 2: The difference between Comparative Example 1 and Example 1 is that steps S102 and 103 are omitted, and the starch protein fiber (PPI-AF) solution is directly freeze-dried and steam crosslinked to obtain PPI-AF-Gel.

[0046] The materials prepared in Example 1, Comparative Example 1, and Comparative Example 2 were characterized and tested for performance. The results are as follows:

[0047] (1) XRD tests were performed on PPI-AF, MXene, and PPI-AF@MXene. Figure 3 The results showed that PPI-AF@MXene was successfully prepared.

[0048] (2) Scanning electron microscopy (SEM) tests were performed on PPI-AF, MXene, and PPI-AF@MXene. Figure 4 The results in b clearly show that MXene is in an oligolayer morphology, and starch protein cellulose solution (PPI-AF) is deposited in situ on the surface of oligolayer MXene (PPI-AF@MXene). This not only indicates that PPI-AF was successfully compounded onto MXene, but also confirms the integrity of MXene, proving that the structure of MXene was not destroyed by the compounding of PPI-AF.

[0049] (3) Scanning electron microscopy was performed on the PPI-AF@MXene-Gel aerogel. Figure 5 In study a, PPI-AF@MXene-Gel aerogel was found to have a typical honeycomb pore structure with a uniform pore size distribution ranging from 80 μm to 1 mm. Figure 5 b discovered vertically arranged channels in the PPI-AF@MXene-Gel aerogel, which is beneficial for efficient photothermal evaporation and synergistic uranyl ion adsorption.

[0050] (4) The mechanical strength of PPI-AF@MXene-Gel was tested by... Figure 6 In the test, PPI-AF@MXene-Gel demonstrated exceptional load-bearing capacity, withstanding 1000g of weight without any noticeable damage, a load up to 5263 times its own weight. This contributes to the long-term stability of PPI-AF@MXene-Gel.

[0051] (5) The photothermal evaporation performance of PPI-AF-Gel in Comparative Example 2, PPI-AF-Gel@MXene in Comparative Example 1, and PPI-AF@MXene-Gel in Example 1 was tested. The results are as follows: Figure 7 , Figure 7Image a shows the UV-Vis-NIR absorption spectra of PPI-AF-Gel, PPI-AF-Gel@MXene, and PPI-AF@MXene-Gel aerogel in the wavelength range of 300-2500 nm. Based on the evaluation results of standard solar radiation spectrum (AM 1.5G), the light absorption rate of PPI-AF-Gel@MXene is only 88.6%, while the light absorption rate of PPI-AF-Gel without photothermal composite material is only 65.5%. The light absorption rate of PPI-AF@MXene-Gel is as high as 91.6%. Figure 7 As shown in b, after MXene composite, the average stable temperature of the PPI-AF-Gel@MXene and PPI-AF@MXene-Gel evaporator surfaces under dry conditions significantly increased from 43℃ to 69℃ and 72℃, respectively. Figure 7 As shown in Figure c, after MXene composite treatment, the average stable surface temperature of the PPI-AF-Gel@MXene and PPI-AF@MXene-Gel evaporators under humid conditions significantly increased from 33℃ to 43℃ and 45℃, respectively. Figure 7 As shown in Figure d, under simulated sunlight, the surface temperature of PPI-AF@MXene-Gel can rapidly reach 45.3℃ within 2 minutes under 1 solar intensity. Figure 7 As shown in figure e, PPI-AF@MXene-Gel exhibited the highest evaporation rate, at 2.69 kg m³. -2 h -1 The evaporation rate of PPI-AF-Gel@MXene is 2.05 kg m³. - 2 h -1 Combining the water evaporation rates of PPI-AF@MXene-Gel and PPI-AF-Gel@MXene evaporators in the dark, by Figure 7 h calculated that their solar energy conversion efficiencies under one solar irradiation were 85.9% and 84.9%, respectively, indicating that the PPI-AF@MXene-Gel sample has a significant advantage in photothermal conversion efficiency. Figure 7 f represents the evaporation rate of the PPI-AF@MXene-Gel evaporator at different salt concentrations. The evaporation rate decreases with increasing salt concentration, but remains at 2.19 kg / m³ in a 20 wt.% sodium chloride solution. -2 h -1 This indicates that the prepared material sample has excellent salt resistance.

[0052] (6) The actual seawater desalination capacity and salt tolerance of PPI-AF@MXene-Gel aerogel were tested, and the results are as follows: Figure 8As shown in Figure a, before and after treatment of real seawater samples from the South China Sea with PPI-AF@MXene-Gel aerogel, the concentrations of the four main ions Ca2+, K+, Mg2+ and Na+ were significantly reduced by three to four orders of magnitude during the desalination process, enabling the water quality to meet the drinking water standards set by the World Health Organization (WHO). Figure 8 In sample b, the self-cleaning properties of the PPI-AF@MXene-Gel aerogel were observed; 1g of salt was transferred back into the water body within 1 hour. For example... Figure 7 As shown in c, the PPI-AF@MXene-Gel evaporator maintained an almost constant evaporation rate over 30 cycles (3.5 wt.% salinity, 8 h per cycle) at 2.50 kg m³. -2 h -1 The above demonstrates excellent durability. Figure 8 The data shows that the evaporation rate of the PPI-AF-Gel@MXene evaporator decreased over 30 cycles (3.5 wt.% salinity, 8 h per cycle). Figure 8 f represents the color change of the two aerogel evaporators over 30 cycles. The PPI-AF@MXene-Gel evaporator remained black after 30 cycles, while the PPI-AF-Gel@MXene evaporator gradually lightened in color, eventually returning to the color of PPI-AF aerogel. This also demonstrates that coating MXene with starch fibers enhances its stability. Figure 8 The results show that the PPI-AF@MXene-Gel evaporator exhibits superior evaporation rate and solar thermal conversion efficiency compared to most aerogel evaporators.

[0053] (7) The performance of PPI-AF@MXene-Gel aerogel in synergistic uranium extraction through simulated seawater photothermal evaporation was tested and evaluated. For example... Figure 9 The results of study a show that, in simulated seawater with 20 ppm uranium addition, the PPI-AF-Gel aerogel exhibited an adsorption capacity of 726.2 mg uranium within a 180-minute equilibrium time. - U / g, Figure 9 The results showed that the uranium adsorption capacity of the PPI-AF@MXene-Gel aerogel was 833 mg within a 180-minute equilibrium time. - U / g indicates that the adsorption of uranium ions by the PPI-AF@MXene-Gel aerogel is mainly physical adsorption. The adsorption behavior fits well with the pseudo-first-order kinetic model, indicating that the PPI-AF@MXene-Gel aerogel prepared by this method has excellent uranium ion adsorption capacity.

[0054] In summary, the preparation method of the protein fiber composite oligolayer MXene aerogel provided by this invention improves the stability of the photothermal layer MXene by combining pea protein fiber with the oligolayer MXene. Furthermore, the porous aerogel produced by directional cryogenic casting possesses a directional vertical pore structure, which exhibits superior performance compared to disordered pore structures in terms of interfacial evaporation and salt resistance. This not only facilitates the directional migration and removal of salt, improving salt resistance, but also enhances photothermal conversion efficiency and solar evaporation rate, while reducing operating and maintenance costs.

[0055] The composite material of this invention can be applied in fields such as efficient and stable solar thermal conversion, clean water production, and uranium extraction, especially in the field of efficient solar thermal evaporation combined with uranium resource extraction.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing MXene aerogel based on protein fiber composite oligolayer, characterized in that... Includes the following steps: S101 Take 2-8 wt.% pea protein suspension and fibrose it to obtain starch protein fiber suspension; S102 was used to prepare 5 mg / mL-10 mg / mL MXene suspensions; S103 uses an electrostatic adsorption strategy to deposit starch protein fibers in situ onto the MXene surface to obtain a precursor mixture, the pH of which is 1-3; S104 was used to obtain aerogel materials by directional cryogenic casting and vapor-phase crosslinking of the precursor mixture.

2. The method for preparing a protein fiber composite oligolayer MXene aerogel according to claim 1, characterized in that, In step S101, pea protein isolate is dissolved in ultrapure water containing NaCl, and then the pH of the solution is adjusted to 1-3 with hydrochloric acid. After hydration at 4°C for 16 hours, the solution is centrifuged at 10,000 rpm for 20 minutes, and insoluble substances are removed by filtration to obtain a pea protein isolate solution with a mass concentration of 2 wt.%. The solution is then stirred at 250 rpm for 16 hours in an oil bath at 85°C, cooled in an ice bath, and incubated at room temperature for 1 day to obtain a starch protein cellulose solution.

3. The method for preparing a protein fiber composite oligolayer MXene aerogel according to claim 1, characterized in that, In step S102, LiF is weighed and completely dissolved in hydrochloric acid solution to prepare an etching solution. Then, Ti3AlC2 is slowly added to the etching solution. After stirring continuously at 28°C for 24 hours, the mixture is washed until the pH of the mixture becomes 7. After the reaction is completed, the reaction product is washed multiple times to make the pH of the reaction product neutral. The product is then transferred to a clean and dry flask, purged with argon gas, sonicated in an ice bath for 2 hours, and then centrifuged for 1 hour. The supernatant is collected to obtain a suspension solution with a concentration of 8 mg / mL MXene.

4. The method for preparing a protein fiber composite oligolayer MXene aerogel according to claim 1, characterized in that, In step S103, 8 mL of starch protein cellulose solution and 1 mL of MXene suspension are weighed and stirred to obtain a precursor mixture.

5. The method for preparing a protein fiber composite oligolayer MXene aerogel according to claim 4, characterized in that, In step S103, the starch protein fiber solution has a pH of 2; the MXene suspension solution has a pH of 7.

6. The method for preparing a protein fiber composite oligolayer MXene aerogel according to claim 1, characterized in that, In step S104, directional cryogenic casting is performed by directional freezing in a liquid nitrogen environment at -196°C for 30-60 minutes, followed by placing it in a freeze dryer for 2-3 days.

7. The method for preparing a protein fiber composite oligolayer MXene aerogel according to claim 1, characterized in that, In step S104, the vapor-phase crosslinking is specifically achieved by crosslinking with 25% glutaraldehyde vapor in an oven at 40°C for 4 hours.

8. An aerogel material based on a protein fiber composite oligolayer MXene, characterized in that, Prepared according to any one of claims 1 to 7.

9. The application of the protein fiber composite oligolayer MXene-based aerogel material as described in claim 8 in efficient photothermal evaporation synergistic marine uranium extraction.

Images