CN106699550B

CN106699550B - Preparation method of nano Cu-CuBTC type metal organic framework material

Info

Publication number: CN106699550B
Application number: CN201611141908.XA
Authority: CN
Inventors: 王戈; 党蕊; 刘欣; 王芃; 刘丽萍; 高鸿毅
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 2016-12-12
Filing date: 2016-12-12
Publication date: 2020-05-12
Anticipated expiration: 2036-12-12
Also published as: CN106699550A

Abstract

The invention discloses a preparation method of a nano Cu-CuBTC type metal organic framework material, which takes a copper nanosheet as a template and trimesic acid as an organic ligand, and utilizes the characteristic that the copper nanosheet can slowly release copper ions in a high-temperature solution to successfully prepare the nano Cu-CuBTC type metal organic framework material by a hydrothermal method; the method has the advantages of simple equipment, controllable process parameters and extremely high repeatability. The preparation method has the advantages of rich raw materials and low energy consumption, and is beneficial to large-scale production. The nanometer metal framework material has wide application in the aspects of catalyst, adsorption, separation and the like.

Description

Preparation method of nano Cu-CuBTC type metal organic framework material

Technical Field

The invention belongs to the technical field of nano material preparation, and relates to a preparation method of a metal organic framework material.

Background

Metal-organic frameworks (MOFs) have become one of the hot spots in the research of material chemistry as a class of highly ordered novel porous crystalline materials. Because the porous structure of the molecular sieve is similar to that of a molecular sieve, the specific surface area is large, the porosity is high, the chemical modification is possible, and the structural composition is diversified, the porous structure has wide application prospects in the fields of gas storage, adsorption separation and the like. Copper (II) 1,3, 5-benzoate (CuBTC) is a typical MOFs material. The CuBTC has a unique cubic structure mode, multiple adsorption sites, a three-dimensional orthogonal pore channel structure, a unique tuck net structure facing the open pore channel, a large specific surface area and pore volume, and rich unsaturated metal active centers, shows excellent performance in the reaction process of catalysis and adsorbents, and leads to extensive research of technologists.

In the current preparation process and technology, the CuBTC is prepared by a method of carrying out a solvothermal reaction on soluble copper salt and an organic ligand in an organic solvent at normal temperature and normal pressure or by using the organic ligand. The CuBTC prepared by the method has a micro structure, and the process is complex and the energy consumption is large when a nano material is required to be obtained.

The nano copper is used as a copper source template, can slowly release copper ions in a high-temperature solution, and can react with complex ions in the solution in situ to obtain a required product. The method does not need to add other copper salt solution, and can effectively control the size of the obtained product. In addition, the nano copper has active property, and the nano copper which is not completely reacted can also be used as an active center to participate in the reaction processes of catalysis, hot spot conduction and the like.

However, the preparation of the CuBTC material by using nano-copper as a template and a copper source is rarely reported. Therefore, how to obtain the nanoscale CuBTC by using the characteristics of the copper nanosheets and a simple and low-energy-consumption method has important significance.

Disclosure of Invention

In order to solve the problems, the invention provides a brand-new method for preparing the nano CuBTC material, and the method uses copper nano sheets to replace the traditional copper salt as a reaction copper source, thereby effectively controlling the agglomeration phenomenon of the obtained CuBTC product.

The invention is realized by the following technical scheme:

(1) mixing water, glucose and polyvinylpyrrolidone according to a certain mass ratio, and stirring for more than 3 hours to obtain a clear mixed solution;

(2) under the condition of stirring, adding a copper sulfate aqueous solution dropwise into the clear mixed solution in the step (1), stirring at room temperature for 30-60min, and transferring to a hydrothermal reaction kettle to react at 160-200 ℃ for 2.5-4 h;

(3) centrifuging the product obtained in the step (2), washing the product by using deionized water and absolute ethyl alcohol in sequence, and drying the product in vacuum to obtain a copper nanosheet;

(4) adding a certain amount of trimesic acid solution into the copper nanosheets obtained in the step (3) in a hydrothermal reaction kettle, and carrying out heat preservation reaction in an oven;

(5) and after cooling at room temperature, centrifuging the obtained product, washing with absolute ethyl alcohol, and drying in vacuum to obtain the nano Cu-CuBTC type metal organic framework material powder.

The mass ratio of the solution obtained in the step (1), water, glucose and polyvinylpyrrolidone is controlled to be 25:0.5-1: 0.2-1.

The mass ratio of the copper sulfate in the step (2) to the glucose in the step (1) is 1: 2.5-5.

In the step (4), the molar ratio of the copper nanosheets to the trimesic acid is 3-8: 0.25-5.

In the step (4), the concentration of the trimesic acid solution is 5-25 mmol/L; preferably, the trimesic acid solution is a trimesic acid ethanol solution prepared from absolute ethanol.

In the step (4), the reaction temperature of the oven is 100-150 ℃, and the reaction time is 2-10 h.

In the step (5), the nano Cu-CuBTC material is washed by absolute ethyl alcohol.

The invention has the beneficial effects that: the method successfully synthesizes the nano Cu-CuBTC type metal organic framework material for the first time, and has the advantages of simple equipment, controllable process parameters and high repeatability.

Drawings

FIG. 1(a) is an SEM picture of a nano Cu-CuBTC material of the invention;

FIG. 1(b) is a partially enlarged view of FIG. 1 (a);

FIG. 2 is an XRD picture of the nano Cu-CuBTC material of the invention;

FIG. 3 is a TEM image of the nano Cu-CuBTC material of the present invention;

fig. 4 is an SEM picture of the copper nanoplate template of the present invention.

Detailed Description

The invention will be further elucidated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention will occur to those skilled in the art after reading the present disclosure, and such equivalents will fall within the scope of the appended claims.

Example 1

0.4g of glucose, 0.2g of polyvinylpyrrolidone and 16mL of deionized water were stirred at room temperature for 4 hours to obtain a clear mixture. Adding 0.8mmoL of copper sulfate solution into the mixture, stirring for 1 hour, transferring the mixture into a hydrothermal reaction kettle, reacting for 3 hours at 160 ℃, centrifuging the product, sequentially washing the product for three times by using deionized water and absolute ethyl alcohol, and drying the obtained product in a vacuum drying oven to obtain the copper nanosheet. 0.025g of copper nanosheet is dispersed in 10mL of 10mmoL of trimesic acid ethanol solution, and the mixture is placed into a hydrothermal reaction kettle to be subjected to heat preservation reaction for 6 hours at 120 ℃ in an oven. And centrifuging the obtained product, washing with absolute ethyl alcohol, and drying in vacuum to obtain the nano Cu-CuBTC type metal organic framework material powder.

SEM pictures of copper nanoplates are shown in fig. 4;

SEM, XRD and TEM pictures of the nano Cu-CuBTC material are respectively shown in figure 1(a), figure 1(b), figure 2 and figure 3. As can be seen from the figure, the columnar CuBTC material is loaded on the surface of the copper nanosheet, the columnar shape is clear, the dispersity is good, and no obvious agglomeration phenomenon is generated.

Example 2

1.5g of glucose, 1g of polyvinylpyrrolidone and 40mL of deionized water were stirred at room temperature for 4 hours to obtain a clear mixture. Adding 1.5mmoL of copper sulfate solution, stirring for 1h, transferring to a hydrothermal reaction kettle, reacting at 180 ℃ for 3h, centrifuging the product, sequentially washing with deionized water and absolute ethyl alcohol for three times, and drying the obtained product in a vacuum drying oven to obtain the copper nanosheet. 0.05g of copper nanosheet is dispersed in 5mL of 25mmoL of trimesic acid ethanol solution, and the mixture is placed into a hydrothermal reaction kettle to be subjected to heat preservation reaction for 4 hours at the temperature of 100 ℃ in an oven. And centrifuging the obtained product, washing with absolute ethyl alcohol, and drying in vacuum to obtain the nano Cu-CuBTC type metal organic framework material powder.

Example 3

1g of glucose, 0.4g of polyvinylpyrrolidone and 20mL of deionized water were stirred at room temperature for 4 hours to obtain a clear mixture. Adding 1mmoL of copper sulfate solution into the mixture, stirring for 1 hour, transferring the mixture into a hydrothermal reaction kettle, reacting for 4 hours at 170 ℃, centrifuging the product, sequentially washing the product for three times by using deionized water and absolute ethyl alcohol, and drying the obtained product in a vacuum drying oven to obtain the copper nanosheet. 0.04g of copper nanosheet is dispersed in 10mL of 15mmoL of trimesic acid ethanol solution, and the mixture is placed into a hydrothermal reaction kettle to be subjected to heat preservation reaction for 3 hours at the temperature of 130 ℃ in an oven. And centrifuging the obtained product, washing with absolute ethyl alcohol, and drying in vacuum to obtain the nano Cu-CuBTC type metal organic framework material powder.

Claims

1. A preparation method of a nano Cu-CuBTC type metal organic framework material is characterized by comprising the following steps:

(5) after cooling at room temperature, centrifuging the product obtained in the step (4), washing with absolute ethyl alcohol, and drying in vacuum to obtain nano Cu-CuBTC type metal organic framework material powder;

in the step (4), the molar ratio of the copper nanosheet to the trimesic acid is 3-8: 0.25-5;

the nano copper is used as a copper source template, can slowly release copper ions in a high-temperature solution, and can react with complex ions in the solution in situ to obtain a required product; the method does not need to add other copper salt solution, and can effectively control the size of the obtained product; in addition, the nano copper has active property, and the nano copper which is not completely reacted can also be used as an active center to participate in the processes of catalysis and hot spot conduction reaction.

2. The method for preparing a nano Cu-CuBTC type metal organic framework material according to claim 1, wherein: the mass ratio of the solution obtained in the step (1), water, glucose and polyvinylpyrrolidone is controlled to be 25:0.5-1: 0.2-1.

3. The method for preparing a nano Cu-CuBTC type metal organic framework material according to claim 1, wherein: the mass ratio of the copper sulfate in the step (2) to the glucose in the step (1) is 1: 2.5-5.

4. The method for preparing a nano Cu-CuBTC type metal organic framework material according to claim 1, wherein: in the step (4), the concentration of the trimesic acid solution is 5-25 mmol/L; the trimesic acid solution is prepared from absolute ethyl alcohol.

5. The method for preparing a nano Cu-CuBTC type metal organic framework material according to claim 1, wherein: in the step (4), the reaction temperature of the oven is 100-150 ℃, and the reaction time is 2-10 h.

6. The method for preparing a Cu-btc type metal organic framework material according to claim 1, characterized in that: in the step (5), the nano Cu-CuBTC material is washed by absolute ethyl alcohol.