CN113651970A

CN113651970A - Universal method for preparing multi-shell hollow metal organic framework

Info

Publication number: CN113651970A
Application number: CN202110973316.9A
Authority: CN
Inventors: 余东波; 高晴亮; 王菲; 崔接武; 吴玉程
Original assignee: Hefei University of Technology
Current assignee: Hefei University of Technology
Priority date: 2021-08-24
Filing date: 2021-08-24
Publication date: 2021-11-16
Anticipated expiration: 2041-08-24
Also published as: CN113651970B

Abstract

The invention discloses a general method for preparing a multi-shell hollow metal organic framework, which comprises the following steps: (1) dispersing precursors MOFs in an organic solution to form a suspension C; (2) dissolving an organic ligand in an organic solution to form a solution D; (3) and adding 0-10 ml of triethylamine into the solution D, adding the suspension C, keeping the temperature at 0-150 ℃, and keeping the temperature for 5 min-24 h. And (3) centrifugally separating the product, washing the product with ethanol and deionized water for multiple times in sequence, and finally drying the product in an oven at 80-100 ℃ for 10-20 hours to obtain the target MOF powder with the multi-shell hollow structure. The method has the advantages of simple operation, low cost, easy control and observation of the process, and mass production, and the prepared multi-shell hollow MOF material has wide application prospect and can be used in the fields of separation, sensing, catalysis, drug sustained release, wave absorption, energy and the like.

Description

Universal method for preparing multi-shell hollow metal organic framework

Technical Field

The invention relates to the technical field of synthesis of functional material hollow metal organic frameworks, in particular to a general method for preparing a multi-shell hollow metal organic framework.

Background

In recent years, metal-organic frameworks (MOFs) having a periodic network structure formed by self-assembly of metal ions and organic ligands have attracted more and more attention. The MOFs material has the advantages of high porosity, large specific surface area, regular pore channels, adjustable framework size, diversity and modifiability of organic ligands and the like, is widely applied in the fields of separation, hydrogen storage, catalysis, sensing, energy conversion and storage, and shows performance superior to that of a conventional porous crystal structure material. The MOFs with the multi-shell hollow structure is a special micro/nano structure, and a plurality of shell layers are sequentially arranged from outside to inside. Compared with a solid or single-double shell structure, the multi-shell hollow structure not only has the characteristics of large specific surface area, low density and high loading capacity, but also has a plurality of adjustable shell layers, a plurality of adjustable shell interlayer spaces, a plurality of adjustable shell layer thicknesses, porosity and the like, and can be orderly arranged, so that the sequential catalysis or sequential release or absorption of substances is realized. Therefore, in applications such as electrochemical energy storage, solar energy conversion, electromagnetic wave absorption, catalysis, drug delivery, and the like, the MOFs with multi-shell hollow structures are expected to have better performance than solid or single-double shell hollow structures and other common porous structures or nano structures. At present, MOFs with multi-shell hollow structure are widely considered as one of the most promising functional materials. However, compared with MOFs with solid and single-double shell hollow structure, due to the increased complexity of the structure, the synthesis of MOFs with multi-shell hollow structure is more challenging, and the lack of simple, general and controllable synthesis method has become the bottleneck of the development and application of MOFs.

Disclosure of Invention

The object of the present invention is to provide a general method for the preparation of multi-shell hollow metal organic frameworks which allows to solve the technical problems set out in the background art mentioned above.

In order to achieve the purpose, the invention provides the following technical scheme:

a general method for preparing a multi-shell hollow metal organic framework, comprising the steps of:

(1) dispersing a precursor MOFs in an organic solvent to form a suspension C;

(2) dissolving an organic ligand in an organic solution to form a solution D;

(3) and adding 0-10 ml of triethylamine into the solution D, adding the suspension C, keeping the temperature at 0-150 ℃, keeping the temperature for 5 min-24 h, performing centrifugal separation on the product, sequentially washing the product with ethanol and deionized water, and finally drying the product in an oven at 80-100 ℃ for 10-24 h to obtain the target MOF powder with the multi-shell hollow structure.

Preferably, the organic solvent in the steps (1) and (2) is one of methanol, ethanol, a mixed solution of methanol or ethanol and deionized water, and a solution of N, N-diethylacetamide, the organic ligand in the step (2) is 2-methylimidazole and 2, 5-dihydroxyterephthalic acid, and the volume ratio of the solution D to the suspension C in the step (3) is 3: 1.

Preferably, the precursor MOFs material in the step (1) is one of IRMOF-74-II powder, ZnCo-MOF-5 powder, ZnCo-ZIF powder and CuCo-ZIF powder.

Preferably, the preparation method of the IRMOF-74-II powder comprises the following steps of dissolving zinc acetate dihydrate in a mixed solution of ethanol, deionized water and N, N-diethylformamide to form a solution A2, dissolving 3,3 '-dihydroxy-4, 4' -biphenyldicarboxylic acid in a mixed solution of ethanol, deionized water and N, N-diethylformamide to form a solution B2, pouring the solution A2 into the solution B2, transferring the solution A into an autoclave, preserving the temperature at 80-150 ℃ for 12-48 hours, centrifugally separating the product, washing the product with DMF, and drying the product in an oven at 80-100 ℃ for 10-24 hours to obtain the IRMOF-74-II powder.

Preferably, the preparation method of the ZnCo-MOF-5 powder comprises the following steps of dissolving zinc acetate dihydrate and cobalt acetate tetrahydrate in DMF to form a solution A3, dissolving terephthalic acid in DMF to form a solution B3, pouring the solution A3 into the solution B3, transferring the solution into a high-pressure kettle, preserving the temperature for 10-24 hours at 80-120 ℃, centrifugally separating the product, and washing the product with DMF to obtain the ZnCo-MOF-5 powder.

Preferably, the preparation method of the ZnCo-ZIF powder comprises the following steps of dissolving cobalt nitrate hexahydrate and zinc nitrate hexahydrate in deionized water to form a solution A4, dissolving 2-methylimidazole and hexadecyl trimethyl ammonium bromide in deionized water to form a solution B4, pouring the solution A4 into the solution B4, stirring for 5min to 10h, centrifugally separating a product, washing with ethanol and deionized water in sequence, and drying in an oven at 80 to 100 ℃ for 10 to 24h to obtain the ZnCo-ZIF powder.

Preferably, the preparation method of the CuCo-ZIF powder comprises the steps of dissolving cobalt nitrate hexahydrate and copper nitrate trihydrate into deionized water to form a solution A5, dissolving 2-methylimidazole and hexadecyl trimethyl ammonium bromide into deionized water to form a solution B5, pouring the solution A5 into the solution B5, stirring for 5min to 10h, centrifugally separating the product, washing with ethanol and deionized water in sequence, and drying in an oven at 80-100 ℃ for 10-24 h to obtain the CuCo-ZIF powder.

Compared with the prior art, the invention has the beneficial effects that:

1) the MOFs material prepared by the invention is not a common hollow structure with a solid single-shell layer or a double-shell layer, but has a unique multi-shell hollow structure, and is suitable for preparing three-dimensional multi-shell hollow MOFs particles and one-dimensional multi-shell layer MOFs nanotubes;

2) the preparation method adopted by the invention is convenient to operate, only one step is needed for converting the precursor into a multi-shell precursor, the reaction time is short, the requirements on the types of raw materials and equipment are less, and the cost is low;

3) the method adopted by the invention can realize large-scale production and preparation of the multi-shell hollow MOFs, and has high yield. The porous carbide, selenide, phosphide, sulfide, nitride and the like with a multi-shell hollow structure can be obtained after different pretreatments (such as carbonization treatment, selenization treatment, phosphating treatment, vulcanization treatment, nitridation treatment and the like) are carried out at high temperature, the product obtained by the pretreatment has excellent electrochemical energy storage performance, can be directly put into production by utilizing the existing equipment and applied to electrochemical energy storage and electromagnetic wave absorption, shows excellent electrochemical performance and wave absorption performance, has good industrial application prospect, and can be used in the fields of separation, sensing, catalysis, drug sustained release, wave absorption, energy and the like.

Drawings

FIG. 1 is a scanning electron micrograph of IRMOF-74-II prepared in example 1.

FIG. 2 is a scanning electron micrograph of ZIF-8 prepared from IRMOF-74-II of example 1.

FIG. 3 is a scanning electron micrograph of ZnCo-MOF-5 prepared in example 2.

FIG. 4 is a scanning electron micrograph of ZnCo-ZIF prepared from ZnCo-MOF-5 of example 2.

FIG. 5 is a transmission electron micrograph of ZnCo-ZIF prepared from ZnCo-MOF-5 of example 2.

FIG. 6 is a scanning electron micrograph of ZnCo-ZIF prepared in example 3.

FIG. 7 is a scanning electron micrograph of ZnCo-MOF-74 prepared from ZnCo-ZIF of example 3.

FIG. 8 is a transmission electron micrograph of ZnCo-MOF-74 prepared from ZnCo-ZIF of example 3.

FIG. 9 is a scanning electron micrograph of CuCo-ZIF prepared in example 4.

FIG. 10 is a scanning electron micrograph of CuCo-MOF-74 prepared from CuCo-ZIF according to example 4.

FIG. 11 is a transmission electron micrograph of CuCo-MOF-74 prepared from CuCo-ZIF of example 4.

FIG. 12 is a graph of the rate capability of ZnCo-MOF-74 made from ZnCo-ZIF applied to a lithium ion battery after high temperature carbonization in example 3.

FIG. 13 is a graph showing rate capability of ZnCo-MOF-74 prepared from ZnCo-ZIF and applied to a potassium ion battery in example 3 after high temperature carbonization.

FIG. 14 is a graph of the rate capability of ZnCo-MOF-74 prepared from ZnCo-ZIF applied to a sodium ion battery after high temperature selenization in example 3.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

(1) the preparation method of the IRMOF-74-II powder comprises the following steps:

dissolving 0.2g of zinc acetate dihydrate in 0.05ml of ethanol, 0.05ml of deionized water, dissolving 1ml of N, N-diethylformamide to form a solution A2, dissolving 88mg of 3,3 '-dihydroxy-4, 4' -biphenyldicarboxylic acid in 0.05ml of ethanol, 0.05ml of deionized water, and dissolving 1ml of N, N-diethylformamide to form a solution B2, pouring the solution A2 into the solution B2, placing the solution A2 into an autoclave, preserving the temperature for 24 hours at 110 ℃, centrifugally separating the product, washing the product with DMF, and drying the product in an oven at 80 ℃ for 10 hours to obtain IRMOF-74-II powder;

(2) dispersing 0.2g of IRMOF-74-II powder in a mixed solution of 9ml of ethanol and 1ml of deionized water to form a suspension C;

(3) dissolving 15g of 2-methylimidazole in a mixed solution of 27ml of ethanol and 3ml of deionized water to form a solution D;

(4) and (3) heating the solution D in a water bath to 75 ℃, adding 75 mu l of triethylamine, pouring the suspension C, stirring for 1h, centrifugally separating the product, washing with ethanol and deionized water in sequence, and finally drying in an oven at 80 ℃ for 10h to obtain the multi-shell hollow ZIF-8 powder.

Example 2

(1) the preparation method of the ZnCo-MOF-5 powder comprises the following steps:

dissolving 1.3g of zinc acetate dihydrate and 0.262g of cobalt acetate tetrahydrate in 35ml of DMF to form a solution A3, dissolving 0.15g of terephthalic acid in 15ml of DMF to form a solution B3, pouring the solution A3 into the solution B3, transferring the solution into a high-pressure kettle, preserving the temperature for 10 hours at 95 ℃, centrifugally separating a product, and then washing the product with DMF in sequence to obtain ZnCo-MOF-5 powder;

(2) dispersing 0.2g of ZnCo-MOF-5 powder into 10ml of ethanol solution to form suspension C;

(3) dissolving 2g of 2-methylimidazole in 30ml of ethanol solution to form a solution D;

(4) and (3) placing the solution D at 0 ℃, adding 40 mu l of triethylamine, pouring the suspension C, stirring for 2h, centrifugally separating the product, washing with ethanol and deionized water in sequence, and finally placing in an oven at 80 ℃ for drying for 10h to obtain the multi-shell hollow ZnCo-ZIF powder.

Example 3

(1) the preparation method of the ZnCo-ZIF powder comprises the following steps:

dissolving 0.218g of zinc nitrate hexahydrate and 0.495g of cobalt nitrate hexahydrate in 25ml of deionized water to form a solution A4, dissolving 10.9g of 2-methylimidazole and 0.012g of hexadecyl trimethyl ammonium bromide in 160ml of deionized water to form a solution B4, pouring the solution A4 into the solution B4, stirring for 16min, centrifugally separating a product, and then washing with deionized water and ethanol in sequence to obtain ZnCo-ZIF powder;

dispersing 6mg of ZnCo-ZIF powder in 10ml of DMF to form suspension C;

(3) 6mg of 2, 5-dihydroxyterephthalic acid are dissolved in 30ml of DMF to form a solution D;

(4) and pouring the suspension C into the solution D, placing the solution D into a high-pressure kettle, preserving the temperature for 12 hours at 130 ℃, centrifugally separating the product, washing the product by using ethanol and deionized water in sequence, and finally placing the product into an oven at 80 ℃ for drying for 10 hours to obtain the multi-shell hollow ZnCo-MOF-74 powder.

Example 4

(1) the preparation method of the CuCo-ZIF powder comprises the following steps:

dissolving 0.123g of copper nitrate trihydrate and 0.59g of cobalt nitrate hexahydrate in 25ml of deionized water to form a solution A4, dissolving 10.9g of 2-methylimidazole and 0.012g of hexadecyl trimethyl ammonium bromide in 160ml of deionized water to form a solution B4, pouring the solution A4 into the solution B4, stirring for 16min, centrifugally separating a product, and then washing with deionized water and ethanol in sequence to obtain CuCo-ZIF powder;

(2) dispersing 6mg of CuCo-ZIF powder in 10ml of DMF to form suspension C;

(3) dissolving 12mg of 2, 5-dihydroxyterephthalic acid in 30ml of DMF to form a solution D;

(4) and pouring the suspension C into the solution D, placing the solution D into a high-pressure kettle, preserving the heat for 12 hours at 130 ℃, centrifugally separating the product, then sequentially washing the product with ethanol and deionized water, and finally placing the product into an oven at 80 ℃ to dry the product for 10 hours to obtain the multi-shell hollow CuCo-MOF-74 powder.

From examples 1, 2, 3, 4 it can be seen that: the invention can realize that the MOF materials such as IRMOF-74-II, ZnCo-MOF-5, ZnCo-ZIF, CuCo-ZIF and the like are converted into the metal organic framework material with the multi-shell hollow structure by the same method.

As can be seen in fig. 1-11:

FIG. 1 is a scanning electron microscope picture of the prepared IRMOF-74-II, and it can be seen that the IRMOF-74-II is smooth nanowires with uniform size, and the diameter of the nanowires is about 800 nm. FIG. 2 is a scanning electron micrograph of multi-shelled hollow ZIF-8 nanotubes prepared from IRMOF-74-II showing that the prepared ZIF-8 still substantially retains the original IRMOF-74-II size, which is about 800nm, but has a slightly rough surface due to the fact that the structure is built up of small ZIF-8 nanoparticles, from which the three-layer structure is clearly visible; FIG. 3 is a scanning electron microscope picture of the prepared ZnCo-MOF-5, and it can be seen that the ZnCo-MOF-5 presents a regular hexahedral structure and has a smooth surface. FIG. 4 is a scanning electron microscope photograph of ZnCo-ZIF prepared from ZnCo-MOF-5, showing that the prepared ZnCo-ZIF still maintains hexahedron shape and has rough surface, which is formed by stacking a large number of ZnCo-ZIF small particles, and the hollow structure can be seen at the break, and two close shells can be clearly seen. FIG. 5 is a transmission electron microscope picture of ZnCo-ZIF prepared from ZnCo-MOF-5, and from the transmission electron microscope picture of FIG. 5, it can be seen that the ZnCo-ZIF prepared from ZnCo-MOF-5 is a three-shell hollow structure, and two shells are relatively close to each other and correspond to a scanning picture. FIG. 6 is a scanning electron micrograph of the prepared ZnCo-ZIF showing a regular cube, about 350nm in size and smooth on the surface. FIG. 7 is a scanning electron micrograph of ZnCo-MOF-74 prepared from ZnCo-ZIF, which shows that the prepared ZnCo-MOF-74 still maintains a tetragonal shape but has a rough surface, and the structure is formed by stacking small ZnCo-MOF-74 nanoparticles. FIG. 8 is a transmission electron microscope photograph of ZnCo-MOF-74 prepared from ZnCo-ZIF, and from the transmission electron microscope photograph of FIG. 8, it can be seen that the ZnCo-MOF-74 prepared from ZnCo-ZIF is a three-shell hollow structure. FIG. 9 is a scanning electron micrograph of the prepared CuCo-ZIF, which shows that the CuCo-ZIF has a regular cube shape, a size of about 350nm, and a smooth surface. FIG. 10 is a scanning electron micrograph of CuCo-MOF-74 prepared from CuCo-ZIF, which shows that the prepared CuCo-MOF-74 still maintains a square shape, but has a rough surface, and the structure is formed by stacking small CuCo-MOF-74 nanoparticles. FIG. 11 is a transmission electron micrograph of ZnCo-MOF-74 prepared from CuCo-ZIF, and from the transmission electron micrograph of FIG. 11, it can be seen that CuCo-MOF-74 prepared from CuCo-ZIF is a three-shell hollow structure.

Pretreatment Process example 1

A high-temperature carbonization pretreatment method comprises the following steps:

(1) ZnCo-MOF-74 prepared from ZnCo-ZIF is placed in a tubular furnace filled with argon atmosphere, heated to 900 ℃ at the heating rate of 2 ℃/min and kept warm for 2 h. And cooling to room temperature, placing the obtained product in a nitric acid aqueous solution at 80 ℃ for acid washing for 24 hours, centrifugally separating the product, washing the product with deionized water and ethanol for multiple times, and placing the product in an oven at 80 ℃ for drying.

(2) And mixing the product obtained after acid cleaning with a conductive agent and a binder according to the ratio of 8: 1: uniformly mixing the mixture in 1-methyl-2-pyrrolidone according to the mass ratio of 1 to prepare slurry, then uniformly coating the slurry on a current collector, and drying the current collector in a vacuum drying oven at the temperature of 80 ℃ for 12 hours.

And assembling the prepared electrode slices into a lithium ion battery and a potassium ion battery in a glove box.

Pretreatment Process example 2

A selenization pretreatment method comprises the following steps:

(1) ZnCo-MOF-74 prepared from ZnCo-ZIF and selenium powder are mixed according to the mass ratio of 1: 1, uniformly mixing, placing in a tubular furnace filled with argon atmosphere, heating to 600 ℃ at the heating rate of 2 ℃/min, and preserving heat for 2 h.

(2) And mixing the obtained product with a conductive agent and a binder according to the weight ratio of 8: 1: uniformly mixing the mixture in 1-methyl-2-pyrrolidone according to the mass ratio of 1 to prepare slurry, then uniformly coating the slurry on a current collector, and drying the current collector in a vacuum drying oven at the temperature of 80 ℃ for 12 hours.

And assembling the prepared electrode slices into a sodium-ion battery in a glove box.

As can be seen in fig. 12-14:

the hollow multi-shell porous carbon and selenide composite structure thereof obtained by adopting the carbonization pretreatment process or the selenylation pretreatment process has excellent electrochemical energy storage performance when being applied to lithium, potassium and sodium ion batteries.

The foregoing is merely exemplary and illustrative of the present invention and various modifications, additions and substitutions may be made by those skilled in the art to the specific embodiments described without departing from the scope of the present invention as defined in the accompanying claims.

Claims

1. A general method for preparing a multi-shell hollow metal organic framework, comprising the steps of:

(1) dispersing a precursor MOFs in an organic solvent to form a suspension C;

(2) dissolving an organic ligand in an organic solution to form a solution D;

2. The general process for the preparation of a multi-shell hollow metal organic framework according to claim 1, characterized in that: the organic solvent in the steps (1) and (2) is one of methanol, ethanol, a mixed solution of methanol or ethanol and deionized water and a N, N-diethyl acetamide solution, the organic ligand in the step (2) is 2-methylimidazole and 2, 5-dihydroxyterephthalic acid, and the volume ratio of the solution D to the suspension C in the step (3) is 3: 1.

3. The general process for the preparation of a multi-shell hollow metal organic framework according to claim 1, characterized in that: the precursor MOFs material in the step (1) is one of IRMOF-74-II powder, ZnCo-MOF-5 powder, ZnCo-ZIF powder and CuCo-ZIF powder.

4. The general process for the preparation of a multi-shell hollow metal organic framework according to claim 3, characterized in that: the preparation method of the IRMOF-74-II powder comprises the following steps of dissolving zinc acetate dihydrate into a mixed solution of ethanol, deionized water and N, N-diethylformamide to form a solution A2, dissolving 3,3 '-dihydroxy-4, 4' -biphenyldicarboxylic acid into a mixed solution of ethanol, deionized water and N, N-diethylformamide to form a solution B2, pouring the solution A2 into the solution B2, transferring the solution B2 into an autoclave, preserving the temperature for 12-48 hours at 80-150 ℃, centrifugally separating the product, washing the product with DMF, and drying the product in an oven at 80-100 ℃ for 10-24 hours to obtain the IRMOF-74-II powder.

5. The general process for the preparation of a multi-shell hollow metal organic framework according to claim 3, characterized in that: the preparation method of the ZnCo-MOF-5 powder comprises the following steps of dissolving zinc acetate dihydrate and cobalt acetate tetrahydrate in DMF to form a solution A3, dissolving terephthalic acid in DMF to form a solution B3, pouring the solution A3 into the solution B3, transferring the solution into a high-pressure kettle, preserving the temperature for 10-24 hours at 80-120 ℃, centrifugally separating a product, and washing the product with DMF to obtain the ZnCo-MOF-5 powder.

6. The general process for the preparation of a multi-shell hollow metal organic framework according to claim 3, characterized in that: the preparation method of the ZnCo-ZIF powder comprises the steps of dissolving cobalt nitrate hexahydrate and zinc nitrate hexahydrate in deionized water to form a solution A4, dissolving 2-methylimidazole and hexadecyl trimethyl ammonium bromide in deionized water to form a solution B4, pouring the solution A4 into the solution B4, stirring for 5 min-10 h, centrifugally separating a product, washing with ethanol and deionized water in sequence, and drying in an oven at 80-100 ℃ for 10-24 h to obtain the ZnCo-ZIF powder.

7. The general process for the preparation of a multi-shell hollow metal organic framework according to claim 3, characterized in that: the preparation method of the CuCo-ZIF powder comprises the steps of dissolving cobalt nitrate hexahydrate and copper nitrate trihydrate into deionized water to form a solution A5, dissolving 2-methylimidazole and hexadecyl trimethyl ammonium bromide into deionized water to form a solution B5, pouring the solution A5 into the solution B5, stirring for 5 min-10 h, centrifugally separating a product, washing with ethanol and deionized water in sequence, and drying in an oven at 80-100 ℃ for 10-24 h to obtain the CuCo-ZIF powder.