CN-121975138-A - Preparation method of micron-sized metal organic framework nanosheets

Abstract

The invention discloses a micron-sized metal-organic framework nano sheet, which is 2D-Cu (NDI-NHEt) NSs, has a thickness of 1.3nm and has a transverse dimension of micron. Compared with the prior art, the invention has the advantages of high crystallinity, ultra-thin thickness (about 1.3 nm) and abundant functional units, has the advantages of simple process, convenient operation, suitability for mass production and the like, and provides reference for MOFs structural design and nano-sheet preparation thereof.

Inventors

• LAN YAQIAN
• YANG YILU
• CHEN YIFA
• LONG MINGJIE

Assignees

• 华南师范大学

Dates

Publication Date

20260505

Application Date

20260227

Claims (7)

1. 1. The preparation method of the micron-sized metal-organic framework nano-sheet is characterized by comprising the following steps of: s1, constructing a three-layer interface reaction system, which comprises the following steps: the bottom layer is a solution containing NDI-NHEt ligand; An intermediate layer, namely an organic solvent mixed solution; the top layer is a solution containing copper salt; s2, reacting the three-layer interface reaction system prepared in the step S1 under a solvothermal condition, and performing suction filtration after the reaction is finished to obtain a two-dimensional layered metal organic frame material; and S3, carrying out ultrasonic stripping on the obtained two-dimensional layered metal organic frame material to obtain the micron-sized metal organic frame nano sheet.
2. 2. The method for preparing the micron-sized metal organic framework nano-sheet according to claim 1, wherein the S1 middle bottom layer is NDI-NHEt dissolved in pyridine and DMF; the intermediate layer is a mixture of DMF and ethanol; The top layer was Cu (NO 3 ) 2 ·3H 2 O in ethanol).
3. 3. The method for preparing the micro-scale metal-organic framework nano-sheet according to claim 1, wherein the solvothermal reaction temperature in S2 is 120 ℃ and the reaction time is 72 hours.
4. 4. The method for preparing the micro-scale metal-organic framework nano-sheet according to claim 1, wherein the two-dimensional layered metal-organic framework material is 2D-Cu (NDI-NHEt).
5. 5. The method for preparing the micro-scale metal-organic framework nano-sheet according to claim 1, wherein the micro-scale metal-organic framework nano-sheet in S3 is 2D-Cu (NDI-NHEt) NSs.
6. 6. The method of claim 4, wherein the ultrasonic stripping in S3 comprises treating 2D-Cu (NDI-NHEt) in ethanol under ultrasonic waves for 30 minutes.
7. 7. A micro-scale metal organic framework nano-sheet prepared by the method according to any one of claims 1-6, wherein the micro-scale metal organic framework nano-sheet is 2D-Cu (NDI-NHEt) NSs, has a thickness of 1.3nm and has a transverse dimension of micro-scale.

Description

Preparation method of micron-sized metal organic framework nanosheets Technical Field The invention relates to the technical field of preparation and application of metal organic framework materials, in particular to a preparation method of a micron-sized metal organic framework nano sheet. Background Metal Organic Frameworks (MOFs) are porous crystalline materials assembled from metal-containing nodes and multifunctional ligands. They have unique characteristics such as higher porosity, larger surface area and abundant structural diversity, and have wide application prospects in numerous applications such as gas separation/storage, biomedical technology, sensing, catalysis or energy storage. Although the progress of MOFs to industrialization has reached a critical stage so far, it covers structural design, morphology regulation, preparation technology or application type, etc. Among them, the specific and uniform morphology of MOFs is a key issue for their further application, and MOFs-based nanoplatelets exhibit superior properties compared to their bulk materials, including advantages of exposed active sites, large aspect ratio, more defects, and ease of processing. However, the preparation of MOFs-based nanoplates by complex structural design or precise morphology control remains a significant challenge in the current stage of development, especially for sizes up to the micrometer scale or larger. Disclosure of Invention The technical problem to be solved by the invention is to overcome the technical defects, and provide a preparation method of the micron-sized metal-organic framework nanosheets with high crystallinity, ultrathin thickness and rich functional units. In order to solve the technical problems, the technical scheme provided by the invention is that the two-dimensional layered material is prepared by designing the side chain structure of the ligand, and then the two-dimensional layered material is subjected to ultrasonic stripping to obtain the micron-sized MOFs nano-sheet. Preferably, the side chain structure of the ligand is designed to modify the NHEt group on the ligand NDI. The two-dimensional MOFs are 2D-Cu (NDI-NHEt). The solvothermal temperature is 120 ℃ and the holding time is 72h. Preferably, the preparation method of the micron-sized MOFs nano-sheet comprises the following steps: For the preparation of 2D-Cu (NDI-NHEt), a solvothermal interfacial synthesis method was used, which comprised three different types of solutions, the bottom layer being NDI-NHEt dissolved in pyridine and DMF, the middle layer being a mixture of DMF and ethanol, the top layer being Cu (NO 3)2·3H2 O in ethanol; And carrying out heat treatment on the system for 72 hours at 120 ℃ to obtain large-size flaky 2D-Cu (NDI-NHEt), carrying out suction filtration after the solvothermal reaction is finished, and carrying out ultrasonic stripping to obtain the micro-sized MOFs nano-sheet 2D-Cu (NDI-NHEt) NSs. Compared with the prior art, the invention has the advantages that: The invention adopts a simple solvothermal method, and prepares the two-dimensional layered material through the side chain structure design of the ligand, and then ultrasonic stripping is carried out to obtain the micron-sized MOFs nanosheet. The obtained catalyst has high crystallinity, ultra-thin thickness (about 1.3 nm) and rich functional units, and provides references for MOFs structural design and nano-sheet preparation thereof; According to the invention, through the design of the side chain structure of the ligand, a two-dimensional metal organic framework material (namely 2D-Cu (NDI-NHEt)) is successfully prepared, and the preparation of the material is realized through the side chain induction effect. The 2D-Cu (NDI-NHEt) can be exfoliated into micro-sized nanoplatelets (i.e., 2D-Cu (NDI-NHEt) NSs). Drawings FIG. 1 shows (a) a schematic structure diagram and (b) a PXRD diagram of 2D-Cu (NDI-NHEt) obtained by the present invention; FIG. 2 shows (a) PXRD pattern, (b) optical pattern of 2D-Cu (NDI-NHEt) NSs, (c) TEM pattern of 2D-Cu (NDI-NHEt) NSs, (D) HR-TEM pattern and FFT pattern of 2D-Cu (NDI-NHEt) NSs (inset), enlarged pattern of circled part in TEM pattern, (f) TEM pattern and element distribution pattern of 2D-Cu (NDI-NHEt) NSs, according to the present invention. Detailed Description The present invention will be described in further detail with reference to the accompanying drawings. A preparation method of a micron-sized metal-organic framework nano-sheet comprises the following steps of S1, constructing a three-layer interface reaction system, wherein the three-layer interface reaction system comprises a bottom layer, a middle layer, a top layer and a two-dimensional layered metal-organic framework material, the bottom layer comprises a solution containing NDI-NHEt ligand, the middle layer comprises an organic solvent mixed solution, the top layer comprises a solution containing copper salt, S2, carrying out suction filtration