A CNT@MOF derived carbon aerogel with high elasticity and high efficient thermoelectric conversion and a preparation method thereof

Abstract

The application relates to a CNT@MOF derived carbon aerogel with high elasticity and high efficient photo-thermal-electric conversion integration and a preparation method thereof. The preparation method comprises the following steps: preparing a dispersion solution of carbon nanotubes and PVP, a dispersion solution of methyl imidazole, and a dispersion solution of a metal salt hydrate; uniformly mixing the dispersion solution of carbon nanotubes and PVP, the dispersion solution of methyl imidazole, and the dispersion solution of the metal salt hydrate through magnetic stirring and ultrasonic treatment to obtain a mixed solution; placing the solution in an open container to perform normal-temperature reaction to obtain a solution containing white precipitates; performing post-treatment centrifugation, washing and vacuum drying steps, and then performing a heat treatment process to prepare the CNT@MOF derived carbon material; and finally preparing the CNT@MOF derived carbon aerogel material with high elasticity through four procedures of mixing, solidification, impregnation and drying. The preparation method can obtain the CNT@MOF derived carbon-based aerogel material with high elasticity and high efficient photo-thermal-electric conversion integration.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aerogel preparation, and particularly relates to a CNT@MOF derived carbon aerogel with high elasticity and high efficient thermoelectric conversion and a preparation method thereof. BACKGROUND

[0002] Nearly half of the global energy consumption is initially from the consumption of thermal energy, 70-85% of the energy is released in the form of waste into the atmosphere, and the effective collection of thermal energy faces great challenges. The thermoelectric conversion technology based on the Seebeck effect is a clean and convenient thermal energy recovery technology for converting thermal energy into electrical energy, and more and more environmentally friendly and low-cost thermoelectric materials have been developed. The porous carbon material prepared by carbonizing the MOF (Metal-Organic Framework, metal-organic framework) with high porosity and highly adjustable composition / structure retains the regular network pore structure and special morphology of the MOF precursor. Moreover, some metal particles in the MOF can provide rich and uniform metal particle doping for the MOF derived carbon material, further improving the performance of the thermoelectric conversion material. However, the agglomeration of the MOF derived carbon material is serious, so the thermoelectric conversion performance is often lost.

[0003] In addition, the limitations of traditional batteries and capacitors as power sources often bring inconvenience due to rigidity and frequent maintenance and charging requirements, so more and more researchers design and study super-elastic thermoelectric conversion materials and devices. High-elasticity thermoelectric materials can convert thermal energy into electrical energy according to the Seebeck effect, and show great potential in providing continuous power for wearable electronic devices. The MOF derived carbon aerogel has excellent structural integrity and mechanical properties, but low elastic strain and irreversible structural collapse seriously limit its application field. The interconnected internal structure composed of micro-scale fibers can alleviate the irreversible structural collapse and improve the elasticity of the aerogel under high strain compression. When sufficient entanglement is generated between the microfibers when assembled into an aerogel, the prepared aerogel will show excellent isotropic elasticity.

[0004] Therefore, it is crucial to develop a carbon aerogel material with high elasticity and high efficient thermoelectric conversion, which guarantees the lightweight and low thermal conductivity of the aerogel material without sacrificing, utilizes one-dimensional flexible carbon nanotubes (CNT) to grow three-dimensional CNT@MOF (CNT is wrapped or embedded in MOF), thereby constructing CNT@MOF derived carbon aerogel material which is not easy to agglomerate and well dispersed, and realizes high elasticity and high efficient thermoelectric conversion through a template construction method. SUMMARY

[0005] In order to solve the technical problems in the prior art, the application provides a CNT@MOF derived carbon aerogel with simple preparation process, high elasticity and high efficiency of thermoelectric conversion and a preparation method thereof.

[0006] The preparation method of the CNT@MOF derived carbon aerogel with high elasticity and high efficiency of thermoelectric conversion comprises the following steps:

[0007] A dispersion solution of carbon nanotubes and PVP (polyvinylpyrrolidone), a dispersion solution of methyl imidazole and a dispersion solution of a metal salt hydrate are prepared.

[0008] The dispersion solution of carbon nanotubes and PVP, the dispersion solution of methyl imidazole and the dispersion solution of the metal salt hydrate are subjected to a normal temperature and pressure reaction.

[0009] The product of the normal temperature and pressure reaction is subjected to centrifugal treatment, washing and vacuum drying treatment to prepare a porous CNT@MOF material.

[0010] The prepared porous CNT@MOF material is subjected to high-temperature heat treatment to obtain a CNT@MOF derived carbon material.

[0011] The CNT@MOF derived carbon material is sequentially mixed with NaCl and PDMS (polydimethylsiloxane), solidified, impregnated and dried to obtain the CNT@MOF derived carbon aerogel.

[0012] Further, the dispersion solution of carbon nanotubes and PVP is prepared by mixing the carbon nanotubes and PVP in methanol. The specific preparation method is that the carbon nanotubes with a diameter of 10-100 nm are dissolved in methanol by ultrasonic method, 2-5 times of PVP in mass of the carbon nanotubes is added, and the solution A, i.e. the dispersion solution of carbon nanotubes and PVP, is obtained by continuing ultrasonic stirring, wherein the mass fraction of the carbon nanotubes is 5%-10%.

[0013] Further, the dispersion solution of methyl imidazole is prepared by dissolving 2-methyl imidazole in a methanol solution. The specific preparation method is that 2-methyl imidazole is dissolved in a methanol solution to obtain the solution B, i.e. the dispersion solution of methyl imidazole, wherein the mass fraction of the dissolved 2-methyl imidazole is 20%-40%.

[0014] Further, the metal salt hydrate dispersion liquid is prepared by dissolving Zn(NO3)2·6H2O and Co(NO3)2·6H2O in methanol. Specifically, Zn(NO3)2·6H2O and Co(NO3)2·6H2O are placed in a beaker, and then methanol is gradually added for dissolution, with stirring during the process. The mass fraction of Zn(NO3)2·6H2O in the obtained mixed solution is 40% to 45%, and the mass fraction of Co(NO3)2·6H2O in the obtained mixed solution is 40% to 45%.

[0015] Further, the normal temperature and pressure reaction of the dispersion liquid of carbon nanotubes and PVP, the dispersion liquid of methyl imidazole, and the metal salt hydrate dispersion liquid includes:

[0016] The dispersion liquid of carbon nanotubes and PVP and the dispersion liquid of methyl imidazole are mixed and then ultrasonically dispersed to obtain a first mixed solution.

[0017] The obtained first mixed solution is poured into the metal salt hydrate dispersion liquid, and ultrasonic stirring is performed to obtain a second mixed solution.

[0018] The second mixed solution is subjected to a normal temperature and pressure reaction.

[0019] Further, the ultrasonic dispersion time is 30 to 60 minutes, and the ultrasonic stirring time is 30 to 60 minutes.

[0020] Further, the normal temperature and pressure reaction is performed at 25°C for 3 to 6 hours.

[0021] Further, the product of the normal temperature and pressure reaction is subjected to centrifugal treatment, washing, and vacuum drying treatment, which includes:

[0022] The product of the normal temperature and pressure reaction is first centrifuged at a speed of 8000 rpm to obtain a white precipitate, and then the white precipitate is washed with 2 to 5 times the amount of methanol, followed by centrifugal treatment. This process is repeated 3 times, with a centrifugal speed of 6000 to 10000 rpm and a time of 2 to 5 minutes each time. The washed white precipitate is vacuum dried to obtain a white powder, with a temperature of 60 to 80°C and a pressure of 0.1 Mpa.

[0023] Further, the high-temperature heat treatment is performed in a nitrogen atmosphere, with a treatment temperature of 800 to 1000°C and a treatment time of 2 to 4 hours. Specifically, the prepared white powder is heated to 800 to 1000°C in a nitrogen atmosphere, and then carbonized at this temperature for 2 to 4 hours to obtain a black CNT@MOF derived carbon powder.

[0024] Further, the mixing, solidification, impregnation and drying of the CNT@MOF derived carbon material with NaCl and PDMS in sequence is to prepare the super-elastic CNT@MOF derived porous carbon aerogel by using the template agent method, and sequentially mixing, solidifying, impregnating and drying four processes. The specific steps are as follows: respectively place the CNT@MOF derived carbon material, NaCl and PDMS in a cylindrical mold and mix thoroughly, and then press the mixture into a dense state, and then solidify in an oven; then immerse the completely solidified mixture in hot water to dissolve the NaCl particles; then put it into an oven for drying to obtain the CNT@MOF derived carbon aerogel. The mass fraction of CNT@MOF derived carbon in the obtained mixture (i.e. aerogel) is 1%-9%, the mass fraction of NaCl in the obtained mixture is 85%-95%, and the mass fraction of PDMS in the obtained mixture is 4%-6%.

[0025] The above steps realize the preparation method of the CNT@MOF derived carbon aerogel with high elasticity and high efficient thermoelectric conversion.

[0026] The present application provides a CNT@MOF derived carbon aerogel with high elasticity and high efficient thermoelectric conversion in a second aspect, which is prepared by the preparation method described in the first aspect of the present application.

[0027] Compared with the prior art, the present application has at least the following beneficial effects:

[0028] (1) Compared with traditional inorganic and organic thermoelectric materials, the present application has super elasticity, and the microstructure is one-dimensional nanotube which is intertwined with each other, combined with three-dimensional CNT@MOF, and the multi-scale structure forms good toughness and high elasticity.

[0029] (2) The preparation method of the CNT@MOF derived carbon material of the present application is a room temperature and normal pressure process, which is different from the traditional high temperature and high pressure hydrothermal process, and has the advantages of short reaction time, low danger, simple operation, no limitation of the shape and size of equipment and container, and can synthesize CNT@MOF derived carbon material in large quantities, quickly and efficiently.

[0030] (3) The aerogel material obtained from the gel, post-processing process and drying in the preparation process of the present application has no any size shrinkage, and the net size forming of the product can be realized, which avoids the problems of cost and cycle increase caused by mechanical processing process.

[0031] (4) The carbon aerogel with CNT@MOF derived carbon material as the matrix in the present application has super elasticity and thermoelectric function, and can be prepared into functional aerogel material and can be practically applied.

[0032] (5) The aerogel material prepared by the present invention is a multi-level network structure constructed by one-dimensional carbon nanotubes with metal nanoparticles on the surface and a three-dimensional aerogel network structure, which is conducive to electron transport and efficiently improves electrothermal conversion.

[0033] (6) The preparation of CNT@MOF-derived carbon aerogels by the present invention has a shorter cycle, higher preparation efficiency, and lower cost compared with the aerogels prepared by sol-gel combined with supercritical drying in the prior art.

[0034] (8) The present invention can use an aqueous phase as a reaction medium, thus avoiding environmental pollution and waste caused by the use of organic solvents during the preparation process.

[0035] (10) The aerogel material prepared by the method of the present invention has a compression resilience of 99.2% and an elongation at break of 6.77 MPa, while the output voltage is as high as 0.9 mV, which can realize efficient thermoelectric conversion application. Attached Figure Description

[0036] Figure 1 This is a flowchart of the preparation process of the present invention.

[0037] Figure 2 This is a SEM image of the CNT@MOF-derived carbon aerogel prepared in Example 1.

[0038] Figure 3 This is a curve showing the number of compressions versus the elastic rebound rate of the CNT@MOF-derived carbon aerogel prepared in Example 1 of this invention.

[0039] Figure 4 This is a graph showing the output voltage versus time of the CNT@MOF-derived carbon aerogel prepared in Example 1 of this invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] In a first aspect, this invention provides a method for preparing a highly elastic and efficient thermoelectric conversion integrated CNT@MOF-derived carbon aerogel, the method being as follows: Figure 1 As shown, it includes the following steps:

[0042] (1) Carbon nanotubes and PVP were mixed in methanol respectively; 2-methylimidazole was dissolved in methanol solution, and then the two were mixed, stirred and sonicated to obtain a mixture.

[0043] The specific steps are: carbon nanotubes with a diameter of 10-100 nm are dissolved in methanol by ultrasonic method, 2-5 times the mass of PVP of the carbon nanotubes is added, and the solution A is obtained by continuing ultrasonic stirring; 2-methyl imidazole is dissolved in methanol solution to obtain solution B. The mass fraction of carbon nanotubes in the obtained mixed solution is 5% to 10%, and the mass fraction of methyl imidazole in the obtained mixed solution is 20% to 40%. After mixing solution A and solution B, ultrasonic dispersion is carried out for 30-60 min.

[0044] (2) Zn(NO3)2·6H2O and Co(NO3)2·6H2O are dissolved in methanol, and then the mixed solution obtained in (1) is poured into the solution, and the mixed solution is aged at room temperature by ultrasonic stirring.

[0045] The specific steps are: Zn(NO3)2·6H2O and Co(NO3)2·6H2O are placed in a beaker, then methanol is gradually added for dissolution, and stirring is continuously carried out during the process. The mass fraction of Zn(NO3)2·6H2O in the obtained mixed solution is 40% to 45%, and the mass fraction of Co(NO3)2·6H2O in the obtained mixed solution is 40% to 45%. Then the mixed solution obtained in step (1) is poured into the above solution, ultrasonic stirring is carried out for 30 min to 60 min, and then normal temperature and pressure reaction is carried out in the beaker at 25°C for 3 to 6 hours.

[0046] (3) The product of normal temperature and pressure reaction obtained in step (2) is sequentially subjected to centrifugation, methanol washing process and vacuum drying step to prepare a porous CNT@MOF material;

[0047] The specific steps are: the product of normal temperature and pressure reaction obtained in step (2) is first centrifuged at a speed of 8000 rpm to obtain a white precipitate, then the white precipitate is washed with 2-5 times of methanol, and then centrifuged. This process is carried out for 3 times, and the centrifugal speed is 6000-10000 rpm, and the time is 2-5 minutes. The washed white precipitate is vacuum dried to obtain a white powder, and the temperature is 60-80°C, and the pressure is 0.1 Mpa.

[0048] (4) The above white powder is subjected to heat treatment, and the treatment system is nitrogen atmosphere, the treatment temperature is 800-1000°C, and the treatment time is 2-4h.

[0049] The specific steps are: the prepared white powder is heated to 800°C under nitrogen atmosphere, and then carbonized at this temperature for 2-4h to obtain a black CNT@MOF derived carbon powder.

[0050] (5) The CNT@MOF derived carbon material obtained in step (4) is prepared into super-elastic CNT@MOF derived porous carbon aerogel by using a template agent method through four procedures of mixing, solidifying, impregnating and drying in sequence.

[0051] The specific steps are as follows: CNT@MOF derived carbon, NaCl and PDMS are respectively placed in a cylindrical mold with an inner diameter of 20 mm and mixed thoroughly, and the mixture is pressed into a dense state, and then solidified in an oven at 100°C for 2 hours. Then the completely solidified mixture is immersed in hot water for 20 hours to dissolve the NaCl particles. The soaked aerogel is placed in an oven at 80°C for 2 hours to obtain CNT@MOF derived carbon aerogel. The mass fraction of CNT@MOF derived carbon in the mixture is 1%-9%, the mass fraction of NaCl in the mixture is 85%-95%, and the mass fraction of PDMS in the mixture is 4%-6%.

[0052] Through the above steps, a carbon material with high elasticity and high efficient thermoelectric conversion is realized.

[0053] The application will be further described below by way of examples, but the scope of protection of the application is not limited to these examples.

[0054] Example 1

[0055] (1) Carbon nanotubes and PVP are respectively mixed in methanol; 2-methylimidazole is dissolved in the methanol solution, and then the two are mixed, stirred and ultrasonicated to obtain a mixed solution.

[0056] The specific steps are as follows: 200 mg of carbon nanotubes with a diameter of 10-100 nm are dissolved in 100 mL of methanol by ultrasonic method, 800 mg of PVP is added, and the stirring is continued to obtain solution A; 800 mg of 2-methylimidazole is dissolved in 100 mL of methanol solution to obtain solution B. After mixing solution A and solution B, ultrasonic dispersion is carried out for 20 min.

[0057] (2) Zn(NO3)2·6H2O and Co(NO3)2·6H2O are dissolved in methanol, and then the mixed solution obtained in (1) is poured into the solution, and ultrasonic stirring is carried out to obtain a mixed solution which is aged at room temperature for 3 hours.

[0058] The specific steps are as follows: 400 mg of Zn(NO3)2·6H2O and 400 mg of Co(NO3)2·6H2O are placed in a beaker, and then methanol is gradually added for dissolution, and stirring is continuously carried out during the process. Then the mixed solution obtained in step (1) is poured into the above solution, ultrasonic stirring is carried out for 30 min, and then normal temperature and pressure reaction is carried out in the beaker at 25°C for 3 hours.

[0059] (3) The product liquid of the normal temperature and normal pressure reaction obtained in step (2) is sequentially subjected to a centrifugation, a methanol washing process and a vacuum drying step to obtain a porous CNT@MOF material;

[0060] The specific steps are as follows: the product of the normal temperature and normal pressure reaction obtained in step (2) is first centrifuged at a speed of 8000 rpm to obtain a white precipitate, and then the white precipitate is washed with 3 times of methanol and then centrifuged, and this process is repeated for 3 times, each time at a speed of 8000 rpm for 3 minutes. The white precipitate after washing is vacuum dried to obtain a white powder, at a temperature of 80°C and a pressure of 0.1 Mpa.

[0061] (4) The white powder is subjected to a heat treatment, and the treatment system is as follows: a nitrogen atmosphere, a treatment temperature of 800°C and a treatment time of 3h.

[0062] The specific steps are as follows: the white powder obtained by preparation is heated to 800°C under a nitrogen atmosphere, and then carbonized at this temperature for 3h to obtain a black CNT@MOF derived carbon powder.

[0063] (5) The CNT@MOF derived carbon material obtained in step (4) is prepared into a super-elastic CNT@MOF derived porous carbon aerogel by a template method, by sequentially performing four processes of mixing, solidification, impregnation and drying.

[0064] The specific steps are as follows: 180mg of CNT@MOF derived carbon, 16g of NaCl and 1g of PDMS are placed in a cylindrical mold with an inner diameter of 20mm and mixed thoroughly, and then the mixture is pressed into a dense state, and then solidified in an oven at 100°C for 2 hours. Then the completely solidified mixture is immersed in hot water for 20 hours to dissolve the NaCl particles. The soaked sponge is placed in an oven at 80°C for 2h to obtain a CNT@MOF derived carbon aerogel.

[0065] The CNT@MOF derived carbon aerogel material prepared in Example 1 has excellent flexibility and elasticity. The mechanical properties, thermoelectric performance and output voltage of the CNT@MOF derived carbon aerogel in Example 1 are tested, and it is found that the surface of the CNT@MOF derived carbon aerogel has no loss of luster, no discoloration and no shedding, and other performance indicators are shown in Table 1.

[0066] Figure 2 is the SEM image of the CNT@MOF derived carbon aerogel prepared in Example 1. It can be seen that the MOF material nucleates and grows uniformly in situ on the dispersed carbon nanotubes to form a CNTs@MOF material, and then the MOFs layer tightly wraps the surface of the CNTs through high-temperature carbonization.

[0067] Figure 3Figure 2 is a plot of the compression times and elastic rebound rate of the CNT@MOF derived carbon aerogel prepared in Example 1. As can be seen, as the compression times gradually increase, the compression rebound rate remains at about 99.3%, and does not weaken until 100 times of compression.

[0068] Figure 4 Figure 3 is a plot of the output voltage versus time of the CNT@MOF derived carbon aerogel prepared in Example 1. As can be seen, as the temperature difference increases, the output voltage gradually increases, when the temperature difference is 80K, the output voltage is 0.68mV; when the temperature difference is 100K, the output voltage is 0.96mV.

[0069] Example 2

[0070] Example 2 is basically the same as Example 1, except that in the preparation process of the dispersion liquid in step 1, no carbon nanotubes are added.

[0071] The output voltage of the CNT@MOF derived carbon aerogel prepared in Example 2 is tested, and it is found that the output voltage decreases, and other performance indicators are shown in Table 1.

[0072] Example 3

[0073] Example 3 is basically the same as Example 1, except that in the preparation process of the dispersion liquid in step 1, the mass ratio of carbon nanotubes is only 2%.

[0074] The output voltage of the CNT@MOF derived carbon aerogel prepared in Example 3 is tested, and it is found that the output voltage decreases, and other performance indicators are shown in Table 1.

[0075] Example 4

[0076] Example 4 is basically the same as Example 1, except that in the preparation process of the dispersion liquid in step 1, the mass ratio of carbon nanotubes is as high as 15%.

[0077] The output voltage of the CNT@MOF derived carbon aerogel prepared in Example 4 is tested, and it is found that the output voltage decreases due to the high thermal conductivity caused by the excessive carbon nanotubes, and other performance indicators are shown in Table 1.

[0078] Example 5

[0079] Example 5 is basically the same as Example 1, except that in the preparation process of the mixed dispersion liquid in step 1, the mass ratio of 2-methylimidazole is 10%.

[0080] The microstructure of the CNT@MOF derived carbon aerogel in Example 4 cannot grow MOF on the carbon nanotubes, resulting in low electrical conductivity and small output voltage, and other performance indicators are shown in Table 1.

[0081] Example 6

[0082] Example 6 is basically the same as Example 1, except that the reaction time of CNT@MOF preparation in step 2 is only 1 hour at normal temperature and pressure.

[0083] In Example 6, no porous CNT@MOF is formed, so that no magnetic nanoparticles can be formed by high-temperature treatment, resulting in a low thermoelectric output voltage. Other performance indicators are shown in Table 1.

[0084] Example 7

[0085] Example 7 is basically the same as Example 1, except that the temperature of high-temperature heat treatment in step 4 is 1000°C, and CNT@MOF-derived carbon aerogel is prepared.

[0086] In Example 7, the CNT@MOF-derived carbon aerogel has good elasticity and formability. Other performance indicators are shown in Table 1.

[0087] Example 8

[0088] Example 8 is basically the same as Example 1, except that the mass ratio of CNT@MOF-derived carbon material in the preparation of aerogel in step 5 is only 0.5%, and CNT@MOF-derived carbon aerogel is prepared.

[0089] The output voltage of the CNT@MOF-derived carbon aerogel prepared in Example 8 is tested, and it is found that the output voltage is reduced. Other performance indicators are shown in Table 1.

[0090] Example 9

[0091] Example 9 is basically the same as Example 1, except that the mass ratio of NaCl in the preparation of aerogel in step 5 is only 50%, and CNT@MOF-derived carbon aerogel is prepared.

[0092] In Example 9, the CNT@MOF-derived carbon aerogel has a dense structure, resulting in a high thermal conductivity. It is found that the output voltage is reduced. Other performance indicators are shown in Table 1.

[0093] Example 10

[0094] Example 10 is basically the same as Example 1, except that the mass ratio of PDMS in the preparation of aerogel in step 5 is only 2%, and CNT@MOF-derived carbon aerogel is prepared.

[0095] The CNT@MOF derived carbon aerogel structure in Example 10 is loose, and the elasticity is poor. Other performance indicators are shown in Table 1. Table 1: Performance indicators of a lightweight and high-efficiency elastic aerogel material prepared in Examples 1-10 and a preparation method thereof, and performance indicators of aerogel materials of comparative examples.

[0096]

[0097] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto. Although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions described in the foregoing examples can still be modified, or some technical features can be replaced by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a CNT@MOF-derived carbon aerogel with high elasticity and high efficient thermoelectric conversion integration, characterized in that, The method comprises the following steps: Preparation of carbon nanotube and PVP dispersion, methyl imidazole dispersion and metal salt hydrate dispersion; carbon nanotube with a diameter of 10-100 nm is dissolved in methanol by ultrasonic method, PVP with a mass of 2-5 times that of the carbon nanotube is added, and the carbon nanotube and PVP dispersion is obtained by continuous ultrasonic stirring; the metal salt hydrate dispersion is prepared by dissolving Zn(NO3)2·6H2O and Co(NO3)2·6H2O in methanol, wherein the mass fraction of Zn(NO3)2·6H2O is 40%-45%, and the mass fraction of Co(NO3)2·6H2O is 40%-45%; The carbon nanotube and PVP dispersion, the methyl imidazole dispersion and the metal salt hydrate dispersion are subjected to normal temperature and pressure reaction; the normal temperature and pressure reaction is carried out at 25°C for 3-6 hours; The product of the normal temperature and pressure reaction is subjected to centrifugal treatment, washing and vacuum drying treatment to prepare a porous CNT@MOF material; The prepared porous CNT@MOF material is subjected to high-temperature heat treatment to obtain a CNT@MOF derived carbon material; The CNT@MOF derived carbon material is sequentially mixed with NaCl and PDMS, solidified, impregnated and dried to obtain a CNT@MOF derived carbon aerogel.

2. The method of claim 1, wherein, The mass fraction of the carbon nanotube in the carbon nanotube and PVP dispersion is 5%-10%.

3. The method of claim 1, wherein, The methyl imidazole dispersion is prepared by dissolving 2-methyl imidazole in a methanol solution, wherein the mass fraction of the dissolved 2-methyl imidazole is 20%-40%.

4. The method of claim 1, wherein, The normal temperature and pressure reaction of the carbon nanotube and PVP dispersion, the methyl imidazole dispersion and the metal salt hydrate dispersion comprises: The carbon nanotube and PVP dispersion and the methyl imidazole dispersion are mixed and subjected to ultrasonic dispersion to obtain a first mixed solution; The first mixed solution is poured into the metal salt hydrate dispersion and subjected to ultrasonic stirring to obtain a second mixed solution; The second mixed solution is subjected to normal temperature and pressure reaction.

5. The method of claim 4, wherein, The ultrasonic dispersion time is 30-60 min, and the ultrasonic stirring time is 30 min-60 min.

6. The method of claim 1, wherein, The centrifugal treatment, washing and vacuum drying treatment of the product of the normal temperature and pressure reaction comprises: the product of the normal temperature and pressure reaction is subjected to centrifugal treatment to obtain white precipitate, the white precipitate is then washed with 2-5 times of methanol, and then the centrifugal treatment and washing are repeatedly performed, with a centrifugal speed of 6000-10000 rpm and a time of 2-5 min each time; the washed white precipitate is subjected to vacuum drying to obtain white powder, with a vacuum drying temperature of 60-80°C and a pressure of 0.1 Mpa.

7. The method of claim 1, wherein, The high-temperature heat treatment is carried out in a nitrogen atmosphere, with a treatment temperature of 800-1000°C and a treatment time of 2-4 h.

8. The method of claim 1, wherein, The CNT@MOF derived carbon material, NaCl and PDMS are placed in a mold and mixed thoroughly, and the mixture is pressed into a dense state, and then solidified in an oven; the completely solidified mixture is immersed in hot water to dissolve NaCl particles, and then placed in an oven for drying, to obtain a CNT@MOF derived carbon aerogel, wherein the mass fraction of the CNT@MOF derived carbon material is 1%-9%, the mass fraction of NaCl is 85%-95%, and the mass fraction of PDMS is 4%-6%.

9. The high-elasticity and high-efficiency thermoelectric conversion integrated CNT@MOF derived carbon aerogel prepared by the method according to any one of claims 1-8.

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