Two-dimensional organic-inorganic superlattice film with high ion selectivity as well as preparation method and application of two-dimensional organic-inorganic superlattice film
By constructing a two-dimensional organic-inorganic superlattice membrane composed of polymer and two-dimensional transition metal oxide monolayer nanosheets, the problem of insufficient selective transport of iodine ions in existing ion sieving membrane materials for high-salt wastewater treatment and permeation power generation has been solved, achieving highly selective and efficient ion separation and energy conversion.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-03-31
AI Technical Summary
Existing ion-sieving membrane materials are difficult to achieve highly selective transport of specific ions in high-salt wastewater treatment and permeation power generation, especially in multi-component mixed salt solutions, where traditional membrane materials struggle to achieve efficient separation and energy conversion of iodide ions.
Two-dimensional organic-inorganic superlattice films were constructed by preparing polymers and two-dimensional transition metal oxide monolayer nanosheets rich in cation defects. Electricity generation was achieved by selective transport of iodine ions. Surface modification and assembly were carried out by combining polymer solutions with two-dimensional transition metal oxide monolayer nanosheets to form a superlattice structure with high ion selectivity.
It achieves highly selective transport and efficient power generation of iodide ions, with a power density of up to 8 W/m2, which is significantly better than commercial standards. Furthermore, the I-/SO42- selectivity ratio is as high as 677, demonstrating superior ion selectivity and stability.
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Figure CN121755058A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a two-dimensional organic-inorganic superlattice membrane with high ion selectivity, its preparation method and application, belonging to the field of separation membrane material technology. Background Technology
[0002] With industrial development and increasing energy demand, traditional energy conversion and separation technologies face problems such as low efficiency, high cost, and poor selectivity, especially in the fields of high-salinity wastewater treatment and permeate energy recovery. Iodine is an important element in industries such as nuclear power and pharmaceutical manufacturing, and its wastewater treatment and resource recovery urgently require efficient and green solutions. Meanwhile, permeate energy power generation technology based on ion-selective transport has attracted widespread attention due to its clean and sustainable characteristics; however, existing ion-screening membrane materials still have shortcomings in terms of ion selectivity, transport flux, and long-term stability.
[0003] While commercially available ion exchange membranes and nanofluidic membranes have made some progress in achieving efficient ion separation and energy conversion, their channel structures are often difficult to precisely control, resulting in limited sieving effects for different ions. Especially in multi-component mixed salt solutions, traditional membrane materials struggle to achieve highly selective transport of specific target ions (such as iodide ions), limiting their application potential in industrial wastewater treatment and salinity gradient power generation. Two-dimensional layered materials, due to their unique nanochannel structure and tunable surface chemistry, offer new possibilities for constructing high-performance ion transport membranes. However, single two-dimensional materials often lack sufficient chemical diversity and structural designability, making it difficult to achieve synergistic control of channel size and surface charge. How to construct composite membrane materials with precise periodicity, structural stability, and high ion selectivity through material design has become a significant challenge in the field of separation membranes and energy materials. Summary of the Invention
[0004] The purpose of this invention is to provide a two-dimensional organic-inorganic superlattice membrane with high ion selectivity, its preparation method, and its application. This invention utilizes polymers and two-dimensional transition metal oxide monolayer nanosheets rich in cation defects to prepare a two-dimensional organic-inorganic superlattice membrane, which can be used as an ion sieving device to generate electricity in iodide-containing solutions by utilizing the selective transport of iodide ions.
[0005] The technical solution for realizing the present invention is:
[0006] A method for preparing a two-dimensional organic-inorganic superlattice film with high ion selectivity includes the following steps:
[0007] (1) The polymer solution is slowly added to the dispersion of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects, and stirred and centrifuged to obtain a surface-modified dispersion of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects, wherein the pH value of the polymer solution and the dispersion of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects is 10~11.
[0008] (2) The dispersion of two-dimensional transition metal oxide monolayer nanosheets with surface-modified cation defects was vacuum filtered, and the membrane layer was peeled off from the filter membrane to obtain a two-dimensional organic-inorganic superlattice membrane with high ion selectivity.
[0009] Furthermore, in step (1), the polymer is not particularly limited and can be a common polymer in the art, such as polystyrene sulfonic acid (PSS), polyethyleneimine (PEI), polydiallyl dimethyl ammonium chloride (PDDA), etc. In a specific embodiment of the present invention, taking PDDA as an example, the average molecular weight is preferably ≥10. 5 .
[0010] Furthermore, in step (1), the two-dimensional transition metal oxide rich in cation defects is not particularly limited, and can be a common two-dimensional transition metal oxide rich in cation defects in the art, such as Ti. 0.87 O2, Ti 0.91 O 2、 MnO2, Ca2Nb3O 10 Etc. In a specific embodiment of the present invention, Ti is used. 0.87 Take O2 as an example.
[0011] Further, in step (1), the mass ratio of the polymer to the two-dimensional transition metal oxide monolayer nanosheet rich in cation defects is 1:5 to 1:25, preferably 1:12.5.
[0012] Further, in step (1), the polymer concentration is 25~100 g / L, preferably 50 g / L; the concentration of the dispersion of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects is 4 mg / mL.
[0013] Furthermore, in step (1), the stirring time is 16~24 h and the centrifugation speed is 20000~22000 rpm.
[0014] Furthermore, in step (2), the pressure of vacuum filtration is 200~900 mbar.
[0015] Furthermore, in step (2), the thickness of the two-dimensional organic-inorganic superlattice film is 10~60 µm, preferably 30 µm.
[0016] Furthermore, in step (2), the filter membrane is not particularly limited and can be a common filter membrane in the art, such as PTFE filter membrane, PVDF filter membrane, cellulose filter membrane, double-pass anodic alumina filter membrane (AAO), etc. In the specific embodiment of the present invention, AAO is used as an example.
[0017] The present invention provides a two-dimensional organic-inorganic superlattice film prepared by the above preparation method.
[0018] The present invention also provides the application of the above-mentioned two-dimensional organic-inorganic superlattice membrane in generating electricity in iodide ion-containing solutions.
[0019] Furthermore, the above-mentioned application method is as follows: using the above-mentioned two-dimensional organic-inorganic superlattice membrane as an ion sieving membrane, it is placed between two solutions with a difference in iodine ion concentration, and electricity generation is achieved through the selective transport of iodine ions.
[0020] Furthermore, the specific application method is as follows:
[0021] (1) Fix the above two-dimensional organic-inorganic superlattice film between two insulating pads with a certain pore size, and install the insulating pads in the middle of the H-type electrolytic cell to obtain a two-chamber electrolytic cell;
[0022] (2) Two solutions with a difference in iodine ion concentration are placed in the left and right chambers of the electrolytic cell, respectively, and electricity is generated by selective transport of iodine ions through a two-dimensional organic-inorganic superlattice membrane.
[0023] Compared with the prior art, the advantages of this invention are:
[0024] (1) For the first time, a two-dimensional organic-inorganic superlattice membrane was used as an ion sieving membrane, and electricity was generated in iodine wastewater with a power density of up to 8 W / m³. 2 Exceeding the commercial standard of 5 W / m 2 .
[0025] (2) Compared with other ion sieving membrane materials, the two-dimensional organic-inorganic superlattice can provide a continuous and low-resistance transport path for specific ions, while setting periodic transport barriers for competing ions, thereby achieving superior ion selectivity. - SO4 2- The selection ratio is as high as 677.
[0026] (3) The preparation method of two-dimensional organic-inorganic superlattice film is simple. It is only necessary to control the type and ratio of reactants to obtain ion selectivity and power generation material with optimal performance. Attached Figure Description
[0027] Figure 1 PDDA in Example 1 50 / Ti 0.87 AFM image of the O2 dispersion sample.
[0028] Figure 2 PDDA in Example 1 50 / Ti 0.87 O2 superlattice film, PDDA in Example 2 25 / Ti 0.87 O2 superlattice film and PDDA in Example 3 100 / Ti 0.87 XRD pattern of O2 superlattice film sample.
[0029] Figure 3 PDDA in Example 1 50 / Ti 0.87 Cross-sectional HRTEM image of O2 superlattice film.
[0030] Figure 4 PDDA in Example 1 50 / Ti 0.87 Cross-sectional SEM image of the O2 superlattice film sample.
[0031] Figure 5 For different PDDAs in Example 1 50 / Ti 0.87 Cross-sectional SEM image of the O2 superlattice film thickness sample.
[0032] Figure 6 The PDDA prepared using Example 1 50 / Ti 0.87 Comparison of concentrations and time of two ions in sodium iodide solution for O2 superlattice film samples.
[0033] Figure 7 The PDDA prepared using Example 1 50 / Ti 0.87 Diffusion current and diffusion voltage diagrams of O2 superlattice film samples under different anion environments.
[0034] Figure 8 The PDDA prepared using Example 1 50 / Ti 0.87 Ion flux and ion transference number of O2 superlattice film samples under different anion environments.
[0035] Figure 9 The PDDA prepared using Example 1 50 / Ti 0.87 Diagram of the monovalent / divalent anion selectivity performance of O2 superlattice film samples.
[0036] Figure 10 PDDA in Example 1 50 / Ti0.87 O2 superlattice film, PDDA in Example 2 25 / Ti 0.87 O2 superlattice film and PDDA in Example 3 100 / Ti 0.87 I of O2 superlattice film sample - SO4 2- Choose a comparison chart.
[0037] Figure 11 PDDA in Example 1 50 / Ti 0.87 O2 superlattice film, PDDA in Example 2 25 / Ti 0.87 O2 superlattice film and PDDA in Example 3 100 / Ti 0.87 The O2 superlattice membrane samples were used as power density curves for ion sieving membrane materials in an iodine wastewater environment (iodide ion concentration of 0.5 M).
[0038] Figure 12 The PDDA prepared using Example 1 50 / Ti 0.87 The power density curve of the O2 superlattice membrane sample as an ion sieving membrane material in an iodine wastewater environment (iodide ion concentration of 0.5 M) for one week.
[0039] Figure 13 For Comparative Example 2, PDDA@Ti 0.87 XRD pattern of O2@PDDA membrane sample.
[0040] Figure 14 For Comparative Example 2, PDDA@Ti 0.87 Cross-sectional SEM image of O2@PDDA membrane sample.
[0041] Figure 15 For iodide ions in Comparative Example 2, PDDA@Ti 0.87 Ion flux and ion transference number in O2@PDDA membrane samples.
[0042] Figure 16 For Comparative Example 2, PDDA@Ti 0.87 O2@PDDA membrane sample I - SO4 2- Choice ratio.
[0043] Figure 17 For Comparative Example 2, PDDA@Ti 0.87 Power density curve of O2@PDDA membrane sample as ion sieving membrane material in iodine wastewater environment (iodide ion concentration of 0.5 M). Detailed Implementation
[0044] The present invention will be further described below with reference to specific embodiments and accompanying drawings.
[0045] This invention provides a two-dimensional organic-inorganic superlattice membrane with a precisely controllable nanochannel structure. The membrane utilizes polymers to modify and orderly assemble negatively charged two-dimensional oxide nanosheets, constructing channels with a periodic interlayer spacing of ~2.0 nm. Due to the differences in structure and charge properties between the two materials, the membrane possesses periodic molecular-level asymmetric channels. Driven by a salinity gradient, these channels can achieve high-flux and high-selectivity transport of specific ions based on differences in ion hydration radius, charge number, and polarizability. Specifically, the periodic molecular-level asymmetric channels provide continuous and low-resistance transport paths for specific ions while simultaneously setting periodic transport barriers for competing ions, thus resulting in high ion selectivity. Based on this, the membrane can also generate electricity in iodine wastewater. Furthermore, the membrane's preparation process is simple; optimal ion-sieving materials can be obtained simply by controlling the type and ratio of polymers and assembly conditions.
[0046] In the following embodiments, a single-layer Ti is used. 0.87 The O2 nanosheets were prepared according to the reference (Angew. Chem. Int. Ed. 2024, 63, e202315947), specifically as follows:
[0047] Weigh 3.07 g K₂CO₃, 0.55 g LiCO₃, and 7.60 g Ti₂O, mix and grind for 30 min, calcine at 800 ℃ for 1 h, grind the resulting solid again for 30 min, and then calcine at 1000 ℃ for 20 h to obtain product K. 0.8 Ti 1.73 Li 0.27 O4. Then add 4 g K 0.8 Ti 1.73 Li 0.27 O4 was stirred in 500 mL of 1 mol / L HCl solution at room temperature for 3 days, with the HCl solution being replaced daily to obtain H2. 1.07 Ti 1.73 O4·H2O. Wash H with distilled water several times. 1.07 Ti 1.73 After neutralizing with O4·H2O, filter and dry at room temperature. Add 2 g of H... 1.07 Ti 1.73 After mixing O4·H2O with 500 mL of tetrabutylammonium hydroxide solution and shaking for 14 days, a monolayer Ti was obtained. 0.87 O2 nanosheet dispersion.
[0048] Example 1
[0049] Preparation of two-dimensional organic-inorganic superlattice films with high ion selectivity:
[0050] (1) Take 50 mL of Ti 0.87 The O2 nanosheet dispersion was diluted to 300 mL with pure water, and then the pH was adjusted to 11 using 0.1 mol / L hydrochloric acid. 50 mL of a 50 g / L solution was then taken. -1 PDDA solution (molecular weight 1.8 × 10⁻⁶) 5 The pH was adjusted to 11 using tetrabutylammonium hydroxide solution. Then, while stirring, it was added at a rate of 2 mL / min. -1 The rate at which the Ti is diluted 0.87 O2 suspension was slowly added dropwise to PDDA solution. After stirring the mixed suspension for 12 h, it was centrifuged three times (2 × 10⁻⁶). 4 Excess polymer was removed by three wash cycles (rpm, 30 minutes). Finally, PDDA-modified Ti... 0.87 O2 is redispersed in water to obtain well-dispersed and stable PDDA. 50 / Ti 0.87 O2 nanosheet dispersion.
[0051] (2) Using AAO with a diameter of 50 mm and a pore size of 80-100 nm as the filter membrane, assemble the filtration device and connect the vacuum pump. A certain volume of PDDA is then drawn. 50 / Ti 0.87 The O2 nanosheet suspension was slowly and uniformly added to a container, and the vacuum pump was turned on. Filtration was carried out at a pressure of 800 mbar for 2 days. After filtration, the membrane layer was peeled off from the AAO filter membrane to obtain PDDA with a certain thickness. 50 / Ti 0.87 O2 superlattice membrane. Because the volume of the solution obtained through filtration is controllable, PDDA membranes of varying thicknesses can be obtained. 50 / Ti 0.87 O2 superlattice film.
[0052] Example 2
[0053] This embodiment is largely the same as Example 1, except that the concentration of the PDDA solution is 25 g / L. -1 PDDA 25 / Ti 0.87 O2 superlattice film.
[0054] Example 3
[0055] This embodiment is largely the same as Example 1, except that the concentration of the PDDA solution is 100 g / L. -1 PDDA 100 / Ti 0.87 O2 superlattice film.
[0056] Example 4
[0057] A superlattice membrane was fixed between two insulating pads with 0.2 mm pores, ensuring that the pores on both sides of the pads were covered. The pads were then aligned and placed in an H-type electrolytic cell, creating two independent chambers separated by the superlattice membrane. Iodide ion solution and pure water were placed in the left and right chambers of the electrolytic cell, respectively, for efficient ion sieving and electricity generation.
[0058] For PDDA in Example 1 50 / Ti 0.87 AFM characterization of the O2 nanosheet dispersion, such as Figure 1 As shown, PDDA 50 / Ti 0.87 The O2 nanosheets are single-layer nanosheets with a thickness of approximately 2.0 nm. XRD tests were performed on the superlattice films in Examples 1, 2, and 3, as shown... Figure 2 As shown, PDDA 50 / Ti 0.87 The XRD pattern of the O2 superlattice film shows three broad peaks in the low-angle region. These three diffraction peaks are located at 4.8°, 9.1°, and 14.8°, representing out-of-plane reflections at 010, 020, and 030 degrees, respectively, characteristic of the two-dimensional layered structure. Calculations based on Bragg's equation indicate that the interlayer spacing corresponding to its first-order diffraction is approximately 2.0 nm, a value significantly greater than that of pure Ti. 0.87 The bulk thickness of the O2 nanosheets is approximately 1.1 nm. Furthermore, with increasing PDDA content, the XRD diffraction peaks systematically shift towards lower angles, indicating an increase in interlayer spacing. Conversely, with decreasing PDDA content, the interlayer spacing decreases. Next, Figure 3 Cross-sectional high-resolution transmission electron microscopy (HRTEM) images and their line scan analysis further confirm that PDDA 50 / Ti 0.87 The O2 superlattice film contains repeating d-intervals of approximately 2.0 nm, in which inorganic Ti... 0.87 The O2 layer (bright area) and the organic PDDA layer (dark area) are arranged in a periodic alternation. This directly proves that the organic (PDDA) and inorganic (Ti) layers are interspersed. 0.87 Successful construction of a superlattice structure with periodically alternating O2 layers. This contributes to the development of PDDA. 50 / Ti 0.87 SEM testing was performed on the O2 superlattice film, such as... Figure 4 As shown, the membrane material has a two-dimensional sheet-like structure composed of nanosheets, and a thickness of approximately 30 micrometers. Figure 5As shown, the membrane thickness can be controlled by adjusting the volume of the nanosheet dispersion used for filtration in step (2) of Example 1. The thickness of the prepared series of superlattice membranes can be precisely controlled in the range of 10 to 60 micrometers, and all membranes of all thicknesses maintain a well-preserved layered stacked structure.
[0059] To evaluate the anion / cation selective permeation behavior of the superlattice membrane, a 0.1 M NaI solution was injected into the left chamber of the electrolyzer, and an equal volume of deionized water was injected into the right chamber. Diffusion tests were performed under concentration gradient-driven conditions. Figure 6 As shown, after 8 hours of permeation diffusion testing, the concentration of iodide ions was six times that of sodium ions, which proves that PDDA... 50 / Ti 0.87 O2 superlattice films exhibit excellent anion selectivity.
[0060] To further explore PDDA 50 / Ti 0.87 The transport performance of O2 superlattice membranes for different anions was studied by selecting five common anions with different hydration diameters and diffusion coefficients found in industrial iodine wastewater. From... Figure 7 It can be clearly seen that, under the same concentration gradient, I - The corresponding diffusion current (I) diff ) and diffusion voltage (V diff All of these values were the highest, significantly superior to other anions. Furthermore, Figure 8 This shows that in PDDA 50 / Ti 0.87 In O2 superlattice films, iodine ions exhibit the highest ion flux and ion transference number. For example... Figure 9 As shown, the calculation results show that PDDA 50 / Ti 0.87 O2 superlattice films exhibit exceptional selectivity for monovalent and divalent anions, with I... - SO4 2- The selection ratio is as high as approximately 680, Br - SO4 2- The selection ratio also reached approximately 340. Figure 10 The I of superlattice films with different PDDA contents were shown. - SO4 2- Choice ratio.
[0061] Based on the excellent monovalent / divalent ion selectivity of superlattice membranes, this study investigates their permeation electrogenic performance in iodine wastewater using superlattice membranes as the membrane material. Figure 11 As shown, in iodine wastewater with an iodide ion concentration of 0.5 M, PDDA 50 / Ti 0.87 The power density of the O2 superlattice film can reach 7.7 W / m².-2 Despite PDDA 50 / Ti 0.87 O2 superlattice film and PDDA 100 / Ti 0.87 The power density of O2 superlattice films is lower than that of PDDA. 50 / Ti 0.87 O2 superlattice film, but still higher than the commercial standard of 5.0 W / m. -2 Furthermore, this PDDA 50 / Ti 0.87 The O2 superlattice membrane exhibits good stability in iodine wastewater with an iodine ion concentration of 0.5 M. Figure 12 It has the potential for commercial application.
[0062] Comparative Example 1
[0063] Take 50 mL Ti 0.87 The O2 nanosheet dispersion was diluted with pure water to 300 mL, and then 50 mL of a 50 g / L concentration was taken. -1 PDDA solution (molecular weight 1~2×10) 5 Then, while stirring, add 2 mL per min. -1 The rate at which the Ti is diluted 0.87 When the O2 suspension is slowly dripped into the PDDA solution, the nanosheet dispersion flocculates, making it impossible to achieve surface modification of single-layer nanosheets.
[0064] Comparative Example 2
[0065] First, 10 mL of a 50 g / L PDDA solution was vacuum filtered to form a pre-coating layer on a PP filter membrane; subsequently, 20 mL of Ti was filtered. 0.87 An O2 dispersion was applied to deposit the PDDA layer; finally, 10 mL of a 50 g / L PDDA solution was filtered and used to coat the Ti layer. 0.87 Above the O2 layer. After filtration, the membrane layer is peeled off from the PP filter membrane to obtain PDDA@Ti. 0.87 O2@PDDA composite membrane.
[0066] PDDA@Ti in Comparative Example 2 0.87 The O2@PDDA composite film was characterized by XRD, such as Figure 13 As shown, the XRD pattern of this composite film exhibits three broad peaks in the low-angle region, representing out-of-plane reflections at 010, 020, and 030, characteristic of a two-dimensional layered structure. Calculations based on Bragg's equation indicate that the interlayer spacing corresponding to its first-order diffraction is approximately 1.1 nm, a value equal to that of pure Ti. 0.87 The bulk thickness of the O2 nanosheets is approximately 1.1 nm. This indicates that PDDA was not successfully modified onto the monolayer Ti.0.87 O2 nanosheet surface. Furthermore, PDDA@Ti 0.87 SEM analysis of the O2@PDDA composite film revealed that the layered structure of the film was not very obvious, indicating that PDDA did not exhibit periodic and orderly insertion between the nanosheet layers. Figure 14 ).
[0067] Figure 15 Display, with PDDA 50 / Ti 0.87 Compared to O2 superlattice films, PDDA@Ti 0.87 The iodine ion flux and ion transference number of the O2@PDDA composite membrane were significantly reduced. This indicates that it does not have excellent iodine ion selectivity and permeability. Figure 16 The display shows that PDDA@Ti 0.87 O2@PDDA composite membrane I - SO4 2- Only 200.
[0068] Utilizing PDDA@Ti 0.87 The O2@PDDA composite membrane was used as the membrane material in a study to measure its permeation electrostatic performance in iodine wastewater. For example... Figure 17 As shown, in iodine wastewater with an iodide ion concentration of 0.5 M, PDDA@Ti 0.87 The power density of the O2@PDDA composite membrane reaches 4.5 W / m³. -2 5.0 W m below the commercial standard -2 .
Claims
1. A method for the preparation of two-dimensional organic-inorganic superlattice films with high ionic selectivity, characterized in that, The method comprises the following steps: (1) slowly adding a polymer solution into a dispersion liquid of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects, stirring and centrifuging to obtain a dispersion liquid of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects and surface-modified, wherein the pH value of the polymer solution and the dispersion liquid of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects is 10-11; (2) vacuum suction filtering the dispersion liquid of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects and surface-modified, peeling off the membrane layer from the filter membrane to obtain a two-dimensional organic-inorganic superlattice membrane with high ion selectivity.
2. The production method according to claim 1, characterized by, In step (1), the polymer is polystyrene sulfonic acid, polyethyleneimine or polydiallydimethylammonium chloride.
3. The preparation method according to claim 1, characterized in that, In step (1), the two-dimensional transition metal oxide rich in cation defects is Ti 0.87 O2, Ti 0.91 O 2、 MnO2or Ca2Nb3O 10 .
4. The method of claim 1, wherein, In step (2), the filter membrane is a PTFE filter membrane, a PVDF filter membrane, a cellulose filter membrane or an AAO filter membrane.
5. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of the polymer to the two-dimensional transition metal oxide monolayer nanosheets rich in cation defects is 1:5-1:25, preferably 1:12.5; the concentration of the polymer is 25-100 g / L, preferably 50 g / L; the concentration of the dispersion liquid of two-dimensional transition metal oxide monolayer nanosheets rich in cation defects is 4 mg / mL; in step (2), the thickness of the two-dimensional organic-inorganic superlattice membrane is 10-60 µm, preferably 30 µm.
6. The method of claim 1, wherein, In step (1), the stirring time is 16-24 h, and the centrifugal speed is 20,000-22,000 rpm; in step (2), the pressure of vacuum suction filtering is 200-900 mbar.
7. The two-dimensional organic-inorganic superlattice membrane prepared by the method according to any one of claims 1-6.
8. The two-dimensional organic-inorganic superlattice membrane according to claim 7 is applied to produce electricity in an iodine ion-containing solution.
9. Use according to claim 8, characterized in that, The application method is: taking the two-dimensional organic-inorganic superlattice membrane as an ion sieve membrane, arranging it between two solutions with different iodine ion concentrations, and realizing electricity generation through selective transport of iodine ions.
10. Use according to claim 8, characterized in that, The specific application method is: (1) fixing the two-dimensional organic-inorganic superlattice membrane between two insulating gaskets with a certain pore size, and installing the insulating gaskets in the middle of an H-shaped electrolytic cell to obtain a two-chamber electrolytic cell; (2) placing two solutions with different iodine ion concentrations in the left and right chambers of the electrolytic cell, and realizing electricity generation through the selective transport of iodine ions by the two-dimensional organic-inorganic superlattice membrane.