Titanium lithium ion sieve adsorption film and preparation method thereof
By preparing a film-forming method using lithium-ion sieve precursors and MXene sheet materials, the problems of low adsorption capacity and poor cycle performance of titanium-based lithium-ion sieve adsorbents were solved, achieving selective adsorption and enrichment separation of lithium ions, and the materials can be reused.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA NAT PETROLEUM CORP
- Filing Date
- 2024-11-04
- Publication Date
- 2026-05-08
AI Technical Summary
Existing titanium-based lithium-ion sieve adsorbents suffer from problems such as low adsorption capacity, difficulty in recycling powdered adsorbents, and a significant decrease in adsorption capacity after molding.
By preparing a lithium-ion sieve precursor and a two-dimensional transition metal carbide/nitride (MXene) sheet material, a casting solution was prepared and coated to form a Li2TiO3/MXene@PVC precursor membrane. Li was then extracted in HCl solution to obtain an HTO/MXene@PVC titanium-based lithium-ion sieve adsorption membrane.
It achieves selective adsorption and enrichment separation of lithium ions, exhibits good adsorption performance and strong physicochemical stability, and can be regenerated by hydrochloric acid solution, making the material reusable.
Smart Images
Figure CN121988293A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of environmental science and technology, and in particular relates to a titanium-based lithium ion sieve adsorption membrane and its preparation method. Background Technology
[0002] Lithium exists primarily in nature as solid lithium ore and liquid lithium. Solid lithium ore mainly consists of lithium-bearing ores such as pegmatites and sedimentary rocks, while liquid lithium is mainly found in salt lake brines, underground brines, and seawater. Lithium is most abundant in continental saltwater (59%), followed by hard rocks (25%). With the increasing activity of oil exploration and development, a large amount of oilfield water resources have been generated. Oilfield water contains a large amount of sodium (Na₂O₃). + K + In addition to plasma, it is also enriched with various trace elements, such as lithium ions. Recovering and utilizing the lithium resources rich in oilfield water can avoid environmental pollution caused by the direct discharge of oilfield water, and is also of great significance for maximizing resource utilization and sustainable development.
[0003] There are four main methods for obtaining liquid lithium resources: precipitation, extraction, adsorption, and electrochemical methods. Among them, ion sieve adsorption has become the most promising method for lithium extraction from salt lake brine due to its advantages of low toxicity, low cost, chemical stability, and high selectivity. Ion sieve adsorbents mainly include manganese-based lithium ion sieves (HMO) and titanium-based lithium ion sieves (HTO), with titanium-based lithium ion sieves attracting increasing attention due to their strong chemical stability and lower leaching loss rate compared to manganese-based lithium ion sieves. However, existing titanium-based lithium ion sieves suffer from problems such as low adsorption capacity, difficulty in recycling powdered adsorbents in actual production, and a significant decrease in adsorption capacity after molding. Therefore, improvements to existing titanium-based lithium ion sieves are needed. Summary of the Invention
[0004] In order to overcome the shortcomings of the existing technology, the purpose of this application is to provide a titanium-based lithium ion sieve adsorption membrane that can selectively adsorb lithium ions in water, while having good adsorption capacity and circulation performance.
[0005] To achieve the above objectives, in a first aspect, this application provides a method for preparing a titanium-based lithium-ion sieve adsorption membrane, comprising:
[0006] Preparation of lithium-ion sieve precursors;
[0007] Preparation of two-dimensional transition metal carbide / nitride (MXene) sheet materials;
[0008] A casting solution was prepared using solvent, PVC (polyvinyl chloride), lithium-ion sieve precursor, and MXene sheet material.
[0009] After the casting solution was allowed to stand and degas, it was coated onto a clean surface and immersed in water to obtain the Li2TiO3 / MXene@PVC precursor membrane.
[0010] The Li2TiO3 / MXene@PVC precursor membrane was immersed in HCl solution to extract Li, resulting in the HTO / MXene@PVC titanium-based lithium ion sieve adsorption membrane.
[0011] Furthermore, the preparation of lithium-ion sieve precursors includes:
[0012] Li2CO3 and TiO2 were mixed evenly and then calcined to obtain a lithium-ion sieve precursor.
[0013] Furthermore, the molar ratio of Li2CO3 to TiO2 is 0.9-1.1:1.
[0014] Further, the preparation of MXene sheet materials includes:
[0015] The etching material was obtained by etching MAX Ti3AlC2 using LiF;
[0016] The etching material is first washed until a neutral pH is reached;
[0017] The etching material after the first wash was ultrasonicated in an organic solvent, centrifuged once, and then washed a second time with deionized water. After a second centrifugation to remove the residual organic solvent, an intermediate was obtained.
[0018] The intermediate was mixed with deionized water, and the upper d-MXene nanosheet slurry was collected after sonication and centrifugation.
[0019] MXene sheet materials were obtained by freeze-drying d-MXene nanosheet slurry.
[0020] Furthermore, the solvent is at least one selected from N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, acetone, chloroform, and tributyl phosphate.
[0021] Furthermore, the mass ratio of lithium-ion sieve precursor to MXene sheet material in the casting solution is 2-8:1.
[0022] Furthermore, the ratio of the total mass of PVC, lithium ion sieve precursor, and MXene sheet material in the casting solution to the mass of N-methylpyrrolidone is 7-9:13.
[0023] Furthermore, the ratio of the total mass of the lithium-ion sieve precursor and the MXene sheet material in the casting solution to the mass of PVC is 5:3.
[0024] Furthermore, after the casting solution is allowed to stand and degas, it is applied to a clean surface and immersed in water for at least 12 hours.
[0025] Secondly, this application also discloses a titanium-based lithium-ion sieve adsorption membrane, which is prepared by the above-described method.
[0026] The technical effects and advantages of this application are as follows:
[0027] 1. This application uses a film-forming method to fix the lithium-ion sieve precursor in the membrane, thereby directly confining the powdered adsorbent inside the membrane. It is a good application carrier for powdered adsorbents and has broad application prospects.
[0028] 2. The titanium-based lithium ion sieve adsorption membrane prepared in this application has good adsorption performance and can selectively adsorb lithium ions to achieve the effect of enrichment and separation of lithium ions in water.
[0029] 3. The titanium-based lithium-ion sieve adsorption membrane prepared in this application has good physicochemical stability, is easy to recycle, and can be regenerated by hydrochloric acid solution, realizing the reuse of materials and having practical application potential.
[0030] 4. This application uses polyvinyl chloride as the synthetic material, which is widely available, inexpensive, and has both environmental and economic benefits.
[0031] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description
[0032] Figure 1 This is a flowchart of a method for preparing a titanium-based lithium-ion sieve adsorption membrane according to this application;
[0033] Figure 2 Fourier transform infrared spectra of Li2TiO3, MXene sheet material, PVC powder, HTO / MXene@PVC titanium lithium ion sieve adsorption membrane and HTO@PVC membrane;
[0034] Figure 3 The adsorption kinetics curve of lithium ions on the titanium-based lithium ion sieve adsorption membrane of Example 1 is shown.
[0035] Figure 4 The adsorption isotherm of lithium ions by the titanium-based lithium ion sieve adsorption membrane in Example 1 is shown.
[0036] Figure 5 The adsorption capacity of the titanium-based lithium-ion sieve adsorption membrane in Example 1 for lithium ions after five cycles.
[0037] Figure 6The titanium-based lithium-ion sieve adsorption membrane of Example 1 exhibits selective adsorption of lithium ions in the presence of other cations. Detailed Implementation
[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0039] Firstly, such as Figure 1 As shown, this application provides a method for preparing a titanium-based lithium-ion sieve adsorption membrane, comprising:
[0040] 1. Preparation of lithium-ion sieve precursors:
[0041] A lithium-ion sieve precursor was prepared by solid calcination. White powdered Li2CO3 and TiO2 were mixed evenly in a molar ratio of 0.9-1.1:1 (e.g., 0.9:1, 0.95:1, 1:1, 1.05:1 or 1.1:1), and then placed in a muffle furnace for calcination. Preferably, the muffle furnace was heated at a rate of 5℃ / min, and calcined at 700℃ for 4 hours to obtain a white powdered lithium-ion sieve precursor, Li2TiO3.
[0042] 2. Preparation of MXene sheet materials:
[0043] An etching solution was prepared using hydrochloric acid and LiF, and then used to etch MAX Ti3AlC2 to obtain an etchable material. For example, 60 ml of 9 mol / L hydrochloric acid and 3 g of lithium fluoride were used to prepare an etching solution to etch 3 g of MAX Ti3AlC2. The etching stirring speed was 400 rpm, the etching temperature was 40 °C, and the etching time was 24 h.
[0044] After etching is complete, wash the etched material with deionized water for the first time until a neutral pH is reached;
[0045] The etched material after the first wash was ultrasonicated in ethanol, centrifuged once, and then washed a second time with deionized water. After a second centrifugation to remove residual ethanol, the intermediate (Ti3C2T) was obtained. x -MXene), for example, the ultrasonic time can be set to 30 min, the first centrifugation speed is set to 10000 rpm, and the second centrifugation speed is the same as the first centrifugation speed. It should be noted that Ti3C2T x For titanium-based MXene, T xMXene is a family of two-dimensional nanomaterials consisting of a mixture of multiple functional groups in varying proportions. It is composed of various functional groups. (Ti3C2T is an example of a specific type of nanomaterial.) x -MXene (titanium carbide MXene) was reported in 2011 and was the first inorganic compound reported in the MXene family.
[0046] Ti3C2T x MXene is mixed with deionized water, and the upper d-MXene nanosheet slurry is collected after sonication and centrifugation. For example, the sonication time can be set to 10 min, the centrifugation speed can be set to 3500 rpm, and the centrifugation time can be set to 10 min.
[0047] MXene sheet material was obtained by freeze-drying d-MXene nanosheet slurry.
[0048] 3. Prepare the casting solution using solvent, PVC (polyvinyl chloride), lithium-ion sieve precursor, and MXene sheet material:
[0049] At least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, acetone, chloroform, and tributyl phosphate was used as the solvent for the casting solution. Two-dimensional MXene sheet material and lithium-ion sieve precursor were first added to the solvent. The two-dimensional MXene sheet material and lithium-ion sieve precursor were uniformly dispersed in the solvent by ultrasonic stirring. Then, PVC powder was added to the above mixed solution at 80°C under mechanical stirring. After the PVC powder was completely dissolved, heating was stopped, and stirring was continued for at least 12 hours to obtain the casting solution.
[0050] In this casting solution, the mass ratio of lithium-ion sieve precursor to MXene flake material is 2-8:1 (e.g., 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, or 8:1). The mass ratio of the sum of the masses of PVC, lithium-ion sieve precursor, and MXene flake material to the mass of the solvent is 7-9:13. This ratio can be adjusted according to the required viscosity of the casting solution, for example, 7:13, 7.5:13, 8:13, or 8.5:13. The mass ratio of the sum of the masses of lithium-ion sieve precursor and MXene flake material to the mass of PVC is 5:3. This ratio affects the final adsorption capacity of the adsorbent, and the adsorption capacity is optimal when the ratio is 5:3.
[0051] 4. After the casting solution is allowed to stand and degas, it is coated onto a clean surface and immersed in water to obtain the Li2TiO3 / MXene@PVC precursor membrane:
[0052] After the prepared casting solution was allowed to stand and degas, it was coated onto a clean glass plate with a scraper, immersed in water and soaked for at least 12 hours to remove excess solvent, thus obtaining the Li2TiO3 / MXene@PVC precursor film.
[0053] 5. The Li2TiO3 / MXene@PVC precursor membrane was immersed in HCl solution to extract Li, yielding the HTO / MXene@PVC titanium-based lithium-ion sieve adsorption membrane:
[0054] The Li2TiO3 / MXene@PVC precursor membrane was immersed in 0.1 mol / L HCl solution for 24 h to extract Li. The acid-soaked precursor membrane was washed with deionized water until neutral and finally dried in a forced-air oven to obtain the HTO / MXene@PVC titanium-based lithium ion sieve adsorption membrane.
[0055] Secondly, this application discloses a titanium-based lithium-ion sieve adsorption membrane, which is prepared by the above-described method.
[0056] To better illustrate this solution, the following embodiments are provided.
[0057] Example 1
[0058] S1: Place 7.389g of lithium carbonate and 7.987g of titanium dioxide in a mortar, add a small amount of anhydrous ethanol, grind for 20 minutes, and then dry in a forced-air oven to remove excess ethanol. Transfer the mixed powder to a crucible and place it in a muffle furnace, heat to 700℃ at a heating rate of 5℃ / min and calcine for 4 hours to obtain the lithium ion sieve precursor Li2TiO3;
[0059] S2: 3g of MAX Ti3AlC2 was slowly added to a 60ml aqueous solution of 9mol / L hydrochloric acid and 3g of lithium fluoride. The mixture was stirred at 400rpm and reacted at 40℃ for 24h to etch Al. The mixture was then washed first with deionized water until a neutral pH was reached. Next, the mixture was sonicated in ethanol for 30min, centrifuged at 10000rpm to collect the product, and then washed a second time with deionized water. A second centrifugation at the same speed was performed to remove residual ethanol, yielding the intermediate (Ti3C2T). x The intermediate was then mixed with deionized water, sonicated for 10 min, and centrifuged at 3500 rpm for 10 min. The upper d-MXene nanosheet slurry was collected. The sonication-centrifugation steps were repeated to improve the d-MXene yield. The obtained d-MXene nanosheet slurry was freeze-dried for 3 days to obtain MXene sheet material.
[0060] S3: Add 13ml of N-methylpyrrolidone, 1.67g of MXene flakes, and 3.33g of lithium-ion sieve precursor to a 50ml conical flask. Sonicate for 15 minutes to ensure uniform dispersion of the MXene flakes and lithium-ion sieve precursor in the solvent. Then, under mechanical stirring at 80℃, add 3g of PVC powder to the above mixed solution. Polyvinyl chloride powder (CAS No. 9002-86-2) was stirred until the PVC powder was completely dissolved. After that, heating was stopped and stirring was continued for 12 hours.
[0061] S4: After stopping stirring, let the casting solution stand to remove bubbles, then use a scraper to coat the casting solution onto a clean glass plate, immerse it in water and soak for 12 hours to obtain Li2TiO3 / MXene@PVC precursor film.
[0062] S5: The Li2TiO3 / MXene@PVC precursor membrane was immersed in 0.1mol / L HCl solution for 24h to extract Li. The acid-soaked precursor membrane was then washed with deionized water until neutral and dried in a forced-air oven to obtain HTO / MXene@PVC titanium-based lithium ion sieve adsorption membrane.
[0063] The titanium-based lithium-ion sieve adsorption membrane obtained in this embodiment is dark gray with a thickness of approximately 75 μm. Mechanical property test data shows that the Young's modulus of the lithium-ion sieve adsorption membrane reaches 535.21 MPa.
[0064] Example 2
[0065] The following modifications are made only to S3 in Example 1, while other conditions remain unchanged:
[0066] Add 13 ml of N-methylpyrrolidone, 0.83 g of MXene flakes, and 3.33 g of lithium-ion sieve precursor to a 50 ml Erlenmeyer flask. Sonicate for 15 minutes to ensure uniform dispersion of the MXene flakes and lithium-ion sieve precursor in the solvent. Then, under mechanical stirring at 80°C, add 3 g of PVC powder to the above mixture. Polyvinyl chloride powder (CAS No. 9002-86-2) was heated until the PVC powder was completely dissolved, then heating was stopped and stirring was continued for 12 hours.
[0067] The titanium-based lithium-ion sieve adsorption membrane obtained in this embodiment is gray in color and has a thickness of about 75 μm. The mechanical property test data shows that the Young's modulus of the lithium-ion sieve adsorption membrane reaches 260.17 MPa.
[0068] Example 3
[0069] The following modifications are made only to S3 in Example 1, while other conditions remain unchanged:
[0070] Add 13 ml of N-methylpyrrolidone, 0.56 g of MXene flakes, and 3.33 g of lithium-ion sieve precursor to a 50 ml Erlenmeyer flask. Sonicate for 15 minutes to ensure uniform dispersion of the MXene flakes and lithium-ion sieve precursor in the solvent. Then, under mechanical stirring at 80°C, add 3 g of PVC powder to the above mixture. Polyvinyl chloride powder (CAS No. 9002-86-2) was heated until the PVC powder was completely dissolved, then heating was stopped and stirring was continued for 12 hours.
[0071] The titanium-based lithium-ion sieve adsorption membrane obtained in this embodiment is gray in color and has a thickness of about 75 μm. The mechanical property test data shows that the Young's modulus of the lithium-ion sieve adsorption membrane reaches 333.59 MPa.
[0072] Example 4
[0073] The following modifications are made only to S3 in Example 1, while other conditions remain unchanged:
[0074] Add 13 ml of N-methylpyrrolidone, 0.42 g of MXene flake material, and 3.33 g of lithium-ion sieve precursor to a 50 ml Erlenmeyer flask. Sonicate for 15 minutes to ensure uniform dispersion of the MXene flake material and lithium-ion sieve precursor in the solvent. Then, under mechanical stirring at 80°C, add 3 g of PVC powder to the above mixture. Polyvinyl chloride powder (CAS No. 9002-86-2) was heated until the PVC powder was completely dissolved, then heating was stopped and stirring was continued for 12 hours.
[0075] The titanium-based lithium-ion sieve adsorption membrane obtained in this embodiment is light gray with a thickness of approximately 75 μm. Mechanical property test data shows that the Young's modulus of the lithium-ion sieve adsorption membrane reaches 275.22 MPa.
[0076] Comparative Example
[0077] The following modifications are made only to S3 in the embodiment, while other conditions remain unchanged:
[0078] Add 13 ml of N-methylpyrrolidone and 3.33 g of lithium-ion sieve precursor to a 50 ml Erlenmeyer flask, and sonicate for 15 minutes to disperse the lithium-ion sieve precursor evenly in the solvent. Then, add 3 g of PVC powder to the above mixed solution under mechanical stirring at 80 °C. Polyvinyl chloride powder (CAS No. 9002-86-2) was heated until the PVC powder was completely dissolved, then heating was stopped and stirring was continued for 12 hours.
[0079] The lithium-ion sieve adsorption membrane obtained in this comparative example is white with a thickness of approximately 75 μm. Mechanical property test data show that the Young's modulus of the lithium-ion sieve adsorption membrane reaches 171.72 MPa.
[0080] Fourier transform infrared spectra of the lithium-ion sieve precursor Li2TiO3 (HTO), MXene sheet material, PVC powder, and HTO / MXene@PVC titanium-based lithium-ion sieve adsorption membrane of Example 1, as well as the HTO@PVC membrane prepared in the comparative example, were measured (the adsorption process spectrum was collected 100 times and the average value was taken, and the resolution of the obtained spectrum was 4 cm⁻¹). -1 ),like Figure 2 As shown, 3000-3500cm -1 The broad absorption band representing the stretching vibration of the OH group gradually disappeared with the addition of PVC powder and MXene sheet material. These results indicate that HTO is crosslinked with PVC and MXene through its hydroxyl groups.
[0081] Lithium adsorption experiments were conducted using lithium-ion sieve adsorption membranes prepared in the examples and comparative examples:
[0082] Using LiCl as the lithium ion source, a buffer solution with pH = 9 was prepared using 0.1 mol / L NH4Cl and NH3·H2O solutions, with a volume ratio of NH4Cl to NH3·H2O of 2:1. The dosage of the lithium ion sieve adsorption membrane was 1 g / L. The reaction was carried out in a constant-temperature shaker at 30℃ for 24 h. After the reaction was completed, the suspension was filtered through a 0.22 μm filter membrane, and the lithium concentration was determined using ICP-OES.
[0083] The test results of the titanium-based lithium-ion sieve adsorption membrane prepared in Example 1 are as follows: Figure 3 , 4 As shown, the adsorption of lithium by the titanium-based lithium-ion sieve adsorption membrane conforms to the pseudo-second-order kinetic equation and the Langmuir adsorption isotherm equation. Analysis and calculation show that the adsorption capacity of the titanium-based lithium-ion sieve adsorption membrane for lithium is 25.7 mg / g. Similarly, the adsorption capacity of the titanium-based lithium-ion sieve adsorption membrane in Example 2 is 10.5 mg / g, in Example 3 it is 14.1 mg / g, in Example 4 it is 6.4 mg / g, and the comparative lithium-ion sieve adsorption membrane has an adsorption capacity of 8.6 mg / g. Comparing Examples 1, 2, 3, and 4, it can be seen that the mass ratio of MXene sheet material to lithium-ion sieve precursor has a significant impact on the lithium adsorption capacity of the titanium-based lithium-ion sieve adsorption membrane. By optimizing the ratio, the adsorption capacity of the titanium-based lithium-ion sieve adsorption membrane for lithium can be greatly increased. The comparative example shows that adding MXene sheet material can effectively increase the lithium adsorption capacity of the lithium-ion sieve adsorption membrane.
[0084] Cyclic performance tests of lithium adsorption were conducted using the titanium-based lithium-ion sieve adsorption membrane prepared in Example 1.
[0085] Using LiCl as the lithium ion source, a buffer solution with pH = 9 was prepared using 0.1 mol / L NH4Cl and NH3·H2O solutions, with a volume ratio of 2:1. The dosage of the titanium-based lithium ion sieve adsorption membrane was 1 g / L. The reaction was carried out in a constant-temperature shaker at 30℃ for 24 h. After the reaction, the adsorbed suspension was sampled. The lithium ion sieve adsorption membrane was acid-soaked in 0.1 mol / L HCl solution for 12 h, dried, and then used for the next adsorption experiment, following the same procedure. The adsorption experiment was repeated five times. The collected suspension was filtered through a 0.22 μm filter membrane, and the lithium concentration was determined using ICP-OES. Figure 5 As shown, the adsorption capacity measured after 5 cycles did not change significantly, indicating that the titanium-based lithium ion sieve adsorption membrane has good cycling performance for lithium adsorption.
[0086] The selectivity performance of lithium adsorption was tested using the titanium-based lithium-ion sieve adsorption membrane prepared in Example 1.
[0087] LiCl, KCl, NaCl, and MgSO4 were used as sources of lithium, potassium, sodium, and magnesium ions, respectively. A buffer solution with pH = 9 was prepared using 0.1 mol / L NH4Cl and NH3·H2O solutions, with a volume ratio of NH4Cl to NH3·H2O of 2:1. The dosage of the titanium-based lithium-ion sieve adsorption membrane was 1 g / L. The reaction was carried out in a constant-temperature shaker at 30℃ for 24 h. After the reaction was completed, the adsorbed suspension was sampled, filtered through a 0.22 μm filter, and the concentrations of lithium, sodium, magnesium, and potassium were determined using ICP-OES. Figure 6 As shown, the titanium-based lithium-ion sieve adsorption membrane has good selectivity for lithium.
[0088] In summary, this application uses a film-forming method to immobilize the lithium-ion sieve precursor in a membrane, thereby directly confining the powdered adsorbent within the membrane. The prepared titanium-based lithium-ion sieve adsorption membrane exhibits good physicochemical stability, is easy to recover, and can be regenerated with hydrochloric acid solution, enabling material reuse. By optimizing the component ratio, this application achieves good adsorption performance in the prepared titanium-based lithium-ion sieve adsorption membrane, while also enabling selective adsorption of lithium ions, thus achieving the enrichment and separation of lithium ions in water.
[0089] Finally, it should be noted that the above description is only a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for preparing a titanium-based lithium-ion sieve adsorption membrane, characterized in that, include: Preparation of lithium-ion sieve precursors; Preparation of two-dimensional transition metal carbide / nitride (MXene) sheet materials; A casting solution is prepared using a solvent, PVC, the lithium-ion sieve precursor, and the MXene sheet material; After the casting solution was allowed to stand and degas, it was coated onto a clean surface and then immersed in water to obtain a Li2TiO3 / MXene@PVC precursor membrane. The Li2TiO3 / MXene@PVC precursor membrane was immersed in HCl solution to extract Li, thus obtaining the HTO / MXene@PVC titanium-based lithium ion sieve adsorption membrane.
2. The method for preparing a titanium-based lithium-ion sieve adsorption membrane according to claim 1, characterized in that, The preparation of the lithium-ion sieve precursor includes: Li2CO3 and TiO2 were mixed evenly and then calcined to obtain a lithium-ion sieve precursor.
3. The method for preparing a titanium-based lithium-ion sieve adsorption membrane according to claim 2, characterized in that, The molar ratio of Li2CO3 to TiO2 is 0.9-1.1:
1.
4. The method for preparing a titanium-based lithium-ion sieve adsorption membrane according to claim 1, characterized in that, The preparation of the MXene sheet material includes: The etching material was obtained by etching MAX Ti3AlC2 using LiF; The etching material is first washed until a neutral pH is reached; The etching material after the first washing is ultrasonicated in an organic solvent, centrifuged once, then washed a second time, and centrifuged a second time to remove the residual organic solvent to obtain an intermediate. The intermediate was mixed with water, and the mixture was ultrasonicated and centrifuged before the upper d-MXene nanosheet slurry was collected. The d-MXene nanosheet slurry was freeze-dried to obtain MXene sheet material.
5. The method for preparing a titanium-based lithium-ion sieve adsorption membrane according to claim 1, characterized in that, The solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, acetone, chloroform, and tributyl phosphate.
6. The method for preparing a titanium-based lithium-ion sieve adsorption membrane according to claim 1, characterized in that, The mass ratio of lithium-ion sieve precursor to MXene sheet material in the casting solution is 2-8:
1.
7. The method for preparing a titanium-based lithium-ion sieve adsorption membrane according to claim 1 or 6, characterized in that, The ratio of the total mass of PVC, lithium-ion sieve precursor, and MXene sheet material in the casting solution to the mass of the solvent is 7-9:
13.
8. A method for preparing a titanium-based lithium-ion sieve adsorption membrane according to claim 1 or 6, characterized in that, The ratio of the total mass of the lithium-ion sieve precursor and the MXene sheet material in the casting solution to the mass of PVC is 5:
3.
9. The method for preparing a titanium-based lithium-ion sieve adsorption membrane according to claim 1, characterized in that, After the casting solution is allowed to stand to remove bubbles, it is applied to a clean surface and immersed in water for at least 12 hours.
10. A titanium-based lithium-ion sieve adsorption membrane, characterized in that, The titanium-based lithium ion sieve adsorption membrane is prepared by the method described in any one of claims 1-9.