CN-122006530-A - Functional film with high-efficiency ion separation performance and preparation method and application thereof

CN122006530ACN 122006530 ACN122006530 ACN 122006530ACN-122006530-A

Abstract

The invention discloses a functional membrane with high-efficiency ion separation performance, and a preparation method and application thereof. The functional film is a metal-covalent organic framework film and is of a MOF in COF structure, and comprises a self-supporting COF film matrix and MOF materials grown in the pore channels of the self-supporting COF film matrix in situ. The preparation method comprises the steps of preparing a self-supporting COF film with ion coordination sites through an interfacial polymerization method, immersing the COF film in a metal salt solution to enable metal ions to be combined with the coordination sites, and adding an organic ligand to carry out hydrothermal reaction to obtain the MCOF film. According to the preparation method, a membrane preparation strategy is innovated, the high crystallinity and the sub-nano pore diameter of the MOF material are organically combined with the high stability of the COF, the obtained MCOF membrane has excellent separation performance on single/multivalent cations, the purity of Li + can reach more than 99%, and the preparation method is particularly suitable for the fields of extracting lithium from retired batteries and the like, and can realize the accurate separation of lithium, nickel, cobalt and manganese.

Inventors

ZHANG QINGHUA
Meng Wentong
CHEN SIFAN
ZHAN XIAOLI

Assignees

浙江大学

Dates

Publication Date: 20260512
Application Date: 20260401

Claims (9)

1. The functional film with high-efficiency ion separation performance is characterized in that the functional film is a metal-covalent organic framework film and is of a MOF in COF structure, and is prepared by loading MOF materials on the COF materials in situ, and comprises the following components: the self-supporting COF film substrate is formed by interfacial polymerization of amino monomers and aldehyde monomers, and ion coordination sites are reserved in pore channels of the self-supporting COF film substrate; And the MOF material is grown in situ in a pore canal of the COF film, and is formed by reacting metal ions with the organic ligand after being coordinated with the ion coordination sites.
2. The functional film with high ion separation performance according to claim 1, wherein the ion coordination site is composed of a nitrogen atom in an imine bond formed by condensing an amino monomer with an aldehyde monomer, and a pyridine nitrogen atom or a thiophene sulfur atom in an aldehyde monomer skeleton.
3. The method for producing a functional film having a high-efficiency ion separation performance according to claim 1 or 2, comprising the steps of: Step 1, dissolving an amino monomer and an aldehyde monomer in an organic mixed solvent, and performing ultrasonic dissolution to obtain a precursor solution A; step 2, dissolving a catalyst in water, and obtaining a precursor solution B after ultrasonic dissolution; step 3, placing the precursor solution B in a sample bottle, slowly adding the precursor solution A above the solution B, reacting at an interface to generate a self-supporting COF film, and removing unreacted monomers and a catalyst by using an organic solvent and water; Step 4, dissolving nitrate metal salt in water, and obtaining a solution C after ultrasonic dissolution; dissolving an organic ligand in water, and performing ultrasonic dissolution to obtain a solution D; And 5, vertically immersing the COF film into the solution C for a certain time, adding the solution D into the solution C after fully coordinating metal ions, and reacting for a period of time to obtain the self-supporting MCOF film, namely the functional film with the high-efficiency ion separation performance.
4. The method of producing a functional membrane having high ion separation performance according to claim 3, wherein in the step 1, the amino monomer is at least one of 1,3, 5-tris (4-aminophenyl) benzene, 2,4, 6-tris (4-aminophenyl) -1,3, 5-triazine, tetrakis (4-aminophenyl) porphyrin, and 1,3,6, 8-tetrakis- (p-aminophenyl) -pyrene, the aldehyde monomer is at least one of 2, 6-pyridinedicarboxaldehyde, 2 '-bipyridine-5, 5' -dicarboxaldehyde, and 2,2 '-bithiophene-5, 5' -dicarboxaldehyde, and the organic mixed solution is a mixed solution of mesitylene and ethyl acetate, and the volume ratio thereof is (0.5-3): 1.
5. The method for producing a functional membrane having high-efficiency ion separation performance according to claim 3, wherein in the step 2, the catalyst used is acetic acid, p-toluenesulfonic acid or scandium triflate.
6. The method for preparing a functional film with high-efficiency ion separation performance according to claim 3, wherein the process of constructing the self-supporting COF film by adopting the interfacial polymerization method in the step 3 is carried out under normal pressure, and no interference reaction is carried out for 2-4 days at 30-40 ℃.
7. The method for preparing a functional membrane with high-efficiency ion separation performance according to claim 3, wherein in the step 4, the metal nitrate is zinc nitrate or cobalt nitrate, the concentration of the prepared solution C is 1-50 mM, the concentration of the organic ligand is 2-methylimidazole, and the concentration of the solution D is 0.2-1 mol L -1 .
8. The method for producing a functional film having high-efficiency ion separation performance according to claim 3, wherein the time for immersing the COF film in the solution C in the step 5 is 4 to 48 h, the reaction temperature after adding the solution D is 25 to 50℃and the reaction time is 12 to 24 hours.
9. Use of a functional membrane with efficient ion separation properties according to claim 1 or 2 or a functional membrane with efficient ion separation properties prepared according to any one of claims 3-8 in the field of ion separation, characterized in that the functional membrane with efficient ion separation properties is applied as a cation exchange membrane in an electrodialysis device for selectively separating lithium ions from a mixed solution containing lithium ions and at least one cation of nickel, cobalt, manganese.

Description

Functional film with high-efficiency ion separation performance and preparation method and application thereof Technical Field The invention relates to the technical field of ion separation membrane materials, and discloses a functional membrane with high-efficiency ion separation performance and a preparation method thereof, and the functional membrane is used as an ion membrane in an electrodialysis device for extracting lithium from retired batteries. Background The rapid development of the new energy automobile industry drives the matching quantity of the power battery to increase rapidly, and is accompanied with the retirement of the large-scale battery. The waste ternary battery contains cobalt, nickel, lithium and other resources with higher value. The efficient separation of lithium, nickel, cobalt and manganese is a key link for realizing the high-value recycling of the waste ternary battery and the closed-loop regeneration of the positive electrode material. At present, the wet recovery process of the waste ternary batteries generally takes acid leaching as a starting point, and combines multi-step separation units such as extraction, precipitation and the like to realize recovery. But also has the problems of long process, large acid-base consumption, more waste water and waste residue discharge, limited selective recovery of lithium and the like. The membrane-based separation technology has the characteristics of low energy consumption and easiness in continuous production, and is regarded as a potential alternative or complementary scheme. The core of its separation properties lies in the preparation of membrane materials with high permeation selectivity. Crystalline Porous Materials (CPM), including covalent organic framework materials (covalent organic frameworks, COFs) and metal organic framework materials (metal organic frameworks, MOFs), are ideal candidates as ion separation membranes with high permeability and excellent selectivity due to their high specific surface area, permanent porosity and precisely adjustable, regular pore channels. MOFs, however, are based on coordination bond formation and belong to organic-inorganic hybrid materials with high crystallinity but poor mechanical properties and chemical stability. COFs themselves consist of covalent bonds and have good stability. COFs, however, consist mainly of light elements (C, H, O, N, etc.), lacking functionality. The metal-covalent organic framework Material (MCOFs) combines the advantages of the metal-covalent organic framework material and the covalent organic framework material well, and can realize functional modification of the pore canal while ensuring the stability and crystallinity of the material. Under the cooperation of the sub-nanometer pore canal and the functionalization site, MCOFs is expected to realize the more efficient separation of lithium, nickel, cobalt and manganese. However, how to effectively combine MOFs and COFs materials still presents a significant challenge. Therefore, a simple and efficient MOF-COF composite method is developed, and the preparation of the MCOF novel ion separation membrane with high stability and high selectivity is a key for solving the problem of lithium extraction of retired batteries. Disclosure of Invention Aiming at the situation of the problems, the invention aims at efficiently compounding MOFs and COFs materials, and provides a functional membrane with efficient ion separation performance, a preparation method and application thereof, wherein the functional membrane is a metal-covalent organic framework membrane with efficient single/multivalent cation separation performance, so as to solve the problems that MOFs and COFs are difficult to effectively compound and the function of a single material is limited in the prior art. To achieve the above object, the solution of the present invention is: In one aspect, the invention provides a functional membrane with high-efficiency ion separation performance, wherein the functional membrane is a metal-covalent organic framework membrane (MCOF membrane) with high-efficiency cation separation performance and has high-efficiency lithium selective transmission channels, and the functional membrane belongs to a MOF in COF membrane, namely, the MOF material is loaded on the COF material in situ to prepare a MCOFs membrane. Comprising the following steps: the self-supporting COF film substrate is formed by interfacial polymerization of amino monomers and aldehyde monomers, and ion coordination sites are reserved in pore channels of the self-supporting COF film substrate; And the MOF material is grown in situ in a pore canal of the COF film, and is formed by reacting metal ions with the organic ligand after being coordinated with the ion coordination sites. The COF film with ion coordination sites is formed by interfacial polymerization of amino monomers and aldehyde monomers, and then the continuous COF film is used as a nano-finite fi