In-situ grown carbon nanotube composite heteroatom-doped porous MXene material and preparation method thereof

Abstract

The present invention discloses an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material and a preparation method thereof. The in-situ grown carbon nanotube composite heteroatom-doped porous MXene material is composed of porous MXene nanosheets and heteroatoms doped in the porous MXene nanosheets. The preparation of the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material includes: preparing a heteroatom-doped porous MXene material, placing ferrocene and the heteroatom-doped porous MXene material in a mortar, adding an organic dispersant, grinding until fully mixed, and then drying to obtain a mixture; placing the mixture in a corundum crucible, evenly spreading an ignition agent on the top, putting the crucible into a microwave device, collecting the product after microwave radiation, and thus obtaining the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

Description

Technical Field

[0001] This application relates to the technical field of material preparation, and particularly relates to a porous MXene material with in-situ grown carbon nanotubes and heteroatom doping, and a preparation method thereof. Background Art

[0002] Two-dimensional transition metal carbides or carbonitrides (MXenes) are ceramic materials with two-dimensional sheet structures discovered in 2011 through the cooperation of Professor Yury Gogotis and Professor Michel Barsoum of Drexel University in the United States. Generally, they can be represented by M n+1 X n T z where M refers to transition metals (such as Ti, Zr, Hf, V, Nb, Ta, Cr, Sc, etc.), X refers to C or / and N, n is generally 1-3, and T z refers to surface groups (such as O 2- 、OH - 、F - 、NH3、NH4 + etc.). Currently, MXenes generally originate from ternary layered metal ceramics M n+ 1AX n phase (M is a transition metal element, A is a main group element, X is C and / or N, n is generally 1-3, abbreviated as MAX phase), and the relatively weakly bonded A-site element (such as Al atoms) in the MAX phase is extracted through a mixed solution of HF acid or hydrochloric acid and fluoride.

[0003] MXene is a new type of two-dimensional layered transition metal carbide / nitride. It has a high specific surface area, excellent electrical conductivity, and rich surface functional groups, and has application potential in the fields of electronics, electromagnetics, optics, sensors, catalysis, energy storage, etc. However, like other two-dimensional materials, the two-dimensional layered structure of MXene will spontaneously stack during the assembly process. The dense structure formed by the stacking will affect the conduction of electrons and the transport of ions, and thus affect the effective utilization of the surface active sites of MXene, restricting the expression of its excellent properties.

[0004] Carbon nanotubes are one-dimensional carbon nanomaterials with light weight, extremely high strength and toughness, and excellent mechanical and electrochemical properties. Carbon nanotube composites have the electrical and thermal conductivity of metal materials, the heat resistance and corrosion resistance of ceramic materials, the weavability of textile fibers, and the light weight and easy processability of polymer materials. Combining MXene with carbon nanotubes can greatly improve the strength, elasticity, and fatigue resistance of the material, enabling a qualitative leap in the properties of the composite material.

[0005] There are mainly two commonly used methods to realize the composite of MXene and carbon nanotubes. One is the physical mixing of MXene and finished carbon nanotubes, and the other is the growth of carbon nanotubes on the surface of two-dimensional MXene by chemical vapor deposition. The binding force between physically mixed MXene and carbon nanotubes is weak, the composite is uneven, and the cost is high, making large-scale production difficult. The chemical vapor deposition method has complex process parameters and uneven composite, and it is impossible to precisely control the growth of carbon nanotubes. Summary of the Invention

[0006] The purpose of the embodiments of the present application is to provide a porous MXene material with in-situ grown carbon nanotubes and heteroatom doping, and a preparation method thereof. By the in-situ growth method, the problems in the preparation, processing and application of growing carbon nanotubes on the surface of MXene are solved, and the strength, elasticity and fatigue resistance of the composite material are greatly improved. Moreover, the introduction of impurity atoms can not only provide rich active sites and create defects, but also expand the interlayer spacing, thereby greatly improving the electrochemical energy storage capacity of the material, and at the same time will not affect the excellent high-conductivity two-dimensional sheet structure of the MXene material itself. More importantly, the material preparation method is relatively simple, has low cost, and has the potential for large-scale production.

[0007] According to the first aspect of the embodiments of the present application, there is provided a porous MXene material with in-situ grown carbon nanotubes and heteroatom doping, which is composed of porous MXene nanosheets and heteroatoms doped in the porous MXene nanosheets.

[0008] Preferably, the porous MXene nanosheets are ceramic materials with a porous two-dimensional sheet structure, and the chemical formula is Ti3C2T x .

[0009] Preferably, the heteroatoms are one or more of N, B, and P, and the molar ratio of heteroatoms to porous MXene nanosheets is (1:10) to (1:1), where the molar ratio of B:N:P is (0 to 1):(0 to 4):(0 to 4), preferably 1:2:3.

[0010] According to the second aspect of the embodiments of the present application, there is provided a preparation method of a porous MXene material with in-situ grown carbon nanotubes and heteroatom doping, and the preparation includes the following steps:

[0011] S1: Prepare a porous MXene material with heteroatom doping, including the following steps:

[0012] S11. Preparation of a porous MXene nanosheet solution: Take MXene nanosheets, stir and disperse them in a hydrogen peroxide solution, stir and etch, and then centrifuge and wash the reacted solution, and ultrasonically disperse to obtain a porous MXene nanosheet solution;

[0013] S12. Preparation of heteroatom dispersion: Add nitrogen source, boron source and phosphorus source to the dispersant, and stir well to make it evenly dispersed to obtain the heteroatom dispersion;

[0014] S13. Preparation of precursor material: Add the porous MXene nanosheet solution prepared in S11 to the heteroatom dispersion prepared in S12. After stirring well until evenly mixed, centrifuge and dry the mixture to obtain the precursor material;

[0015] S14. Preparation of heteroatom-doped porous MXene material: Put the precursor material into a corundum crucible, then transfer it to a tubular furnace. In a protective atmosphere, heat at a heating rate, hold the temperature, and naturally cool to room temperature. Collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material;

[0016] S2: Preparation of in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, including the following steps:

[0017] S21. Take ferrocene and the heteroatom-doped porous MXene material prepared in S1 and place them in a mortar. Add an organic dispersant and grind until fully mixed, then dry to obtain a mixture;

[0018] S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread an igniter on the top, put the crucible into a microwave device, and collect the product after microwave radiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

[0019] Preferably, the mass ratio of the MXene nanosheets to the hydrogen peroxide solution is 0.1 - 1, and the mass concentration of the hydrogen peroxide solution is 0.01% - 0.1%.

[0020] Preferably, the etching temperature is 20 - 80 °C, and the etching time is 10 - 100 min.

[0021] Preferably, the nitrogen source is selected from one or more of ammonium sulfate, nitric acid, urea, 1-butyl-3-methylimidazolium tetrafluoroborate (BMI-TFB); the boron source is selected from one or more of sodium borohydride, boric acid, B2H6; the phosphorus source is selected from one or more of phosphoric acid, sodium hypophosphite, hexafluorophosphoric acid, ammonium dihydrogen phosphate.

[0022] Preferably, the dispersant is selected from one or more of deionized water and ethanol; the protective atmosphere is any one or more of argon and nitrogen.

[0023] Preferably, the ferrocene is bis(cyclopentadienyl)iron (chemical formula: Fe(C5H5)2), and the mass ratio of ferrocene to heteroatom-doped porous MXene is (0.5:1) to (1.5:1), preferably 1:1.

[0024] Preferably, the organic dispersant is one or more of toluene, acetone, and dimethyl sulfoxide (DMSO), preferably acetone; the mass ratio of the amount of the organic dispersant to the total amount of ferrocene and heteroatom-doped porous MXene is (1:100) to (1:20).

[0025] Preferably, the ignition agent is selected from one or both of carbon powder and carbon fiber, preferably carbon fiber; the mass ratio of the ignition agent to the mixture is (1:300) to (1:100).

[0026] Preferably, the power of the microwave device is 400 - 1500 W, preferably 900 W; the time of each microwave radiation is 20 s - 80 s, preferably 40 s; the number of microwave radiation times is 1 - 5 times, preferably 3 times.

[0027] Preferably, in S14, it is heated to 200 - 500 °C at a heating rate of 3 - 6 °C / min; after holding for 1 - 5 hours, it is naturally cooled to room temperature.

[0028] The technical solutions provided by the embodiments of the present application may include the following beneficial effects:

[0029] 1. The preparation method of the present invention solves the problems in the preparation, processing, and application of growing carbon nanotubes on the surface of MXene. The production process is simple, easy to control, and low in cost. It is green and pollution-free from raw material use to the preparation process, which is conducive to large-scale industrial production.

[0030] 2. The mild chemical etching of H2O2 can introduce artificial pores on the surface of MXene nanosheets while well preserving the two-dimensional sheet structure of the original nanosheets, which can greatly improve the ion conduction level of MXene.

[0031] 3. The electrons of the heteroatoms can combine with the π electrons on MXene to activate the originally inert π atoms, generating more reaction sites. At the same time, a large number of pore structures and defects generated during the doping process can also effectively improve the electrochemical energy storage capacity.

[0032] 4. The introduction of heteroatoms increases the interlayer spacing of MXene, which is not only beneficial to improving the energy storage capacity of MXene materials but also can effectively overcome the defects of self-stacking and accumulation of MXene itself, improving the cycle stability of the battery.

[0033] 5. The unique structure of carbon nanotubes grown in situ on the surface of MXene has unique advantages in improving the loading rate of lithium sulfide. Lithium sulfide can not only be embedded in the pores between carbon nanotubes, but also in the hollow tube bodies, interlayer gaps and cavity positions of carbon nanotubes. Moreover, carbon nanotubes have the advantages of good chemical stability, large elastic modulus and high mechanical strength, and form an interlaced network structure in the electrode, effectively reducing the stress generated by the volume expansion of the electrode material during the charge and discharge process of the lithium-sulfur battery, and improving the stability of the positive electrode material of the lithium-sulfur battery.

[0034] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and do not limit this application. Detailed implementation manners

[0035] Here, the exemplary embodiments will be described in detail.

[0036] Example 1

[0037] This example provides a preparation method of an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, and the preparation includes the following steps:

[0038] S1. Prepare a heteroatom-doped porous MXene material, including the following steps:

[0039] S11. Preparation of a porous MXene nanosheet solution: Take 30 parts by weight of Ti3C2T x nanosheets and stir and disperse them into 300 parts by weight of a hydrogen peroxide (H2O2) solution with a mass concentration of 0.01%, stir and etch at 20 °C for 10 minutes, and then centrifuge and wash the reaction solution and ultrasonically disperse it to obtain a porous MXene nanosheet solution.

[0040] S12. Preparation of a heteroatom dispersion: Take 100 parts by weight of boric acid with a concentration of 1%, and the boron source can be replaced with sodium borohydride, B2H6; 100 parts by weight of phosphoric acid with a concentration of 1%, and the phosphorus source can be replaced with sodium hypophosphite, hexafluorophosphoric acid, ammonium dihydrogen phosphate; 100 parts by weight of nitric acid with a concentration of 1%, and the nitrogen source can be replaced with ammonium sulfate, urea, 1-butyl-3-methylimidazolium tetrafluoroborate; add 300 parts by weight of deionized water and stir well to obtain a heteroatom dispersion.

[0041] S13. Preparation of a precursor material: Add the porous MXene nanosheet solution prepared in S11 to the heteroatom dispersion prepared in S12, stir well until evenly mixed, and then centrifuge and dry the mixture to obtain a precursor material.

[0042] S14. Preparation of heteroatom-doped porous MXene material: After placing the precursor material in a corundum crucible, transfer it to a tube furnace. In a protective atmosphere with a 1:1 mixture of argon and nitrogen, heat it to 200 °C at a heating rate of 3 °C / min. After holding for 1 hour, naturally cool it to room temperature, and collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material.

[0043] S2: Preparation of in-situ grown carbon nanotube composite MXene material, including the following steps:

[0044] S21. Take 10 parts by weight of ferrocene and 20 parts by weight of the heteroatom-doped porous MXene material prepared above and place them in a mortar. Add 0.3 parts by weight of acetone, which can be replaced by toluene or dimethyl sulfoxide (DMSO); grind for 5 minutes until fully mixed, and then dry to obtain a mixture.

[0045] S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread 0.1 part by weight of carbon fiber on the top, put the crucible into a microwave device, set the power to 400 W and the time to 20 s, and collect the product after 1 microwave radiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

[0046] Example 2

[0047] This example provides a preparation method of an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, and the preparation includes the following steps:

[0048] S1. Preparation of heteroatom-doped porous MXene material, including the following steps:

[0049] S11. Preparation of porous MXene nanosheet solution: Take 30 parts by weight of Ti3C2T x Nanosheets are stirred and dispersed into 300 parts by weight of a hydrogen peroxide (H2O2) solution with a mass concentration of 0.01%, stirred and etched at 20 °C for 10 minutes, and then the reaction solution is centrifuged and washed, and ultrasonically dispersed to obtain a porous MXene nanosheet solution.

[0050] S12. Preparation of heteroatom dispersion: Take 100 parts by weight of boric acid with a concentration of 1%, and the boron source can be replaced by one or more of sodium borohydride and B2H6. Add 100 parts by weight of deionized water, and stir evenly to obtain a heteroatom dispersion.

[0051] S13. Preparation of precursor material: Add the porous MXene nanosheet solution prepared in S11 to the heteroatom dispersion prepared in S12, stir until fully mixed, and then centrifuge and dry the mixture to obtain the precursor material.

[0052] S14. Preparation of heteroatom-doped porous MXene material: After putting the precursor material into a corundum crucible, transfer it to a tube furnace. Under a nitrogen protection atmosphere, heat it to 200 °C at a heating rate of 3 °C / min. After holding for 1 hour, cool it naturally to room temperature, and collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material.

[0053] S2: Preparation of in-situ grown carbon nanotube composite MXene material, including the following steps:

[0054] S21. Take 10 parts by weight of ferrocene and 20 parts by weight of the heteroatom-doped porous MXene material prepared above and place them in a mortar. Add 0.3 parts by weight of acetone, which can be replaced with toluene or dimethyl sulfoxide (DMSO); grind for 5 minutes until fully mixed, and then dry to obtain a mixture.

[0055] S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread 0.1 part by weight of carbon fiber on the top, put the crucible into a microwave device, set the power to 400 W and the time to 20 s, and collect the product after 1 microwave radiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

[0056] Example 3

[0057] This example provides a preparation method of an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, and the preparation includes the following steps:

[0058] S1. Preparation of heteroatom-doped porous MXene material, including the following steps:

[0059] S11. Preparation of porous MXene nanosheet solution: Take 30 parts by weight of Ti3C2T x Stir and disperse the nanosheets into 300 parts by weight of a hydrogen peroxide (H2O2) solution with a mass concentration of 0.01%, stir and etch at 20 °C for 10 minutes, and then centrifuge and wash the reaction solution and ultrasonically disperse it to obtain a porous MXene nanosheet solution.

[0060] S12. Preparation of heteroatom dispersion: Take 100 parts by weight of nitric acid with a concentration of 1%, the nitrogen source can be replaced with ammonium sulfate, nitric acid, urea, 1-butyl-3-methylimidazolium tetrafluoroborate, add 100 parts by weight of deionized water, and stir well to obtain a heteroatom dispersion.

[0061] S13. Preparation of precursor material: Add the porous MXene nanosheet solution prepared in S11 to the heteroatom dispersion prepared in S12, stir until fully mixed, then centrifuge and dry the mixture to obtain the precursor material.

[0062] S14. Preparation of heteroatom-doped porous MXene material: After placing the precursor material in a corundum crucible, transfer it to a tube furnace. Under a nitrogen protection atmosphere, heat it to 200 °C at a heating rate of 3 °C / min. After holding for 1 hour, naturally cool it to room temperature, and collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material.

[0063] S2: Preparation of in-situ grown carbon nanotube composite MXene material, including the following steps:

[0064] S21. Take 10 parts by weight of ferrocene and 20 parts by weight of the heteroatom-doped porous MXene material prepared above and place them in a mortar. Add 0.3 parts by weight of acetone, which can be replaced by toluene or dimethyl sulfoxide (DMSO); grind for 5 minutes until fully mixed, and then dry to obtain a mixture.

[0065] S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread 0.1 part by weight of carbon fiber on the top, put the crucible into a microwave device, set the power to 400 W and the time to 20 s, and collect the product after 1 microwave irradiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

[0066] Example 4

[0067] This example provides a method for preparing an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, and this preparation includes the following steps:

[0068] S1. Preparation of heteroatom-doped porous MXene material, including the following steps:

[0069] S11. Preparation of porous MXene nanosheet solution: Take 30 parts by weight of Ti3C2T x Nanosheets are stirred and dispersed into 300 parts by weight of a hydrogen peroxide (H2O2) solution with a mass concentration of 0.01%, stirred and etched at 20 °C for 10 minutes, and then the reaction solution is centrifuged, washed, and ultrasonically dispersed to obtain a porous MXene nanosheet solution.

[0070] S12. Preparation of heteroatom dispersion: Take 100 parts by weight of phosphoric acid with a concentration of 1%, and the phosphorus source can be replaced with sodium hypophosphite, hexafluorophosphoric acid, or ammonium dihydrogen phosphate. Add 100 parts by weight of deionized water and stir well to obtain a heteroatom dispersion.

[0071] S13. Preparation of precursor material: Add the porous MXene nanosheet solution prepared in S11 to the heteroatom dispersion prepared in S12, stir until fully mixed, then centrifuge and dry the mixture to obtain the precursor material.

[0072] S14. Preparation of heteroatom-doped porous MXene material: After putting the precursor material into a corundum crucible, transfer it to a tubular furnace. Under a nitrogen protection atmosphere, heat it to 200 °C at a heating rate of 3 °C / min. After holding for 1 hour, cool it naturally to room temperature, and collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material.

[0073] S2: Preparation of in-situ grown carbon nanotube composite MXene material, including the following steps:

[0074] S21. Take 10 parts by weight of ferrocene and 20 parts by weight of the above-prepared heteroatom-doped porous MXene material and place them in a mortar. Add 0.3 parts by weight of acetone, which can be replaced by toluene or dimethyl sulfoxide (DMSO); grind for 5 minutes until fully mixed, and then dry to obtain a mixture.

[0075] S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread 0.1 part by weight of carbon fiber on the top, put the crucible into a microwave device, set the power to 400 W and the time to 20 s, and collect the product after 1 microwave radiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

[0076] Example 5

[0077] This example provides a preparation method of an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, and the preparation includes the following steps:

[0078] S1. Preparation of heteroatom-doped porous MXene material, including the following steps:

[0079] S11. Preparation of porous MXene nanosheet solution: Take 30 parts by weight of Ti3C2T x Nanosheets are stirred and dispersed into 300 parts by weight of a hydrogen peroxide (H2O2) solution with a mass concentration of 0.01%, stirred and etched at 20 °C for 10 minutes, and then the reaction solution is centrifuged, washed, and ultrasonically dispersed to obtain a porous MXene nanosheet solution.

[0080] S12. Preparation of heteroatom dispersion: Take 100 parts by weight of boric acid with a concentration of 1%, and the boron source can be replaced by sodium borohydride, B2H6; 100 parts by weight of phosphoric acid with a concentration of 1%, and the phosphorus source can be replaced by sodium hypophosphite, hexafluorophosphoric acid, ammonium dihydrogen phosphate; add 200 parts by weight of deionized water, and stir well to obtain a heteroatom dispersion.

[0081] S13. Preparation of precursor material: Add the porous MXene nanosheet solution prepared in S11 to the heteroatom dispersion prepared in S12, stir well until evenly mixed, then centrifuge and dry the mixture to obtain the precursor material.

[0082] S14. Preparation of heteroatom-doped porous MXene material: After putting the precursor material into a corundum crucible, transfer it to a tube furnace. Under a nitrogen protection atmosphere, heat it to 200 °C at a heating rate of 3 °C / min. After holding for 1 hour, cool it naturally to room temperature, and collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material.

[0083] S2: Preparation of in-situ grown carbon nanotube composite MXene material, including the following steps:

[0084] S21. Take 10 parts by weight of ferrocene and 20 parts by weight of the heteroatom-doped porous MXene material prepared above and place them in a mortar. Add 0.3 parts by weight of dimethyl sulfoxide, which can be replaced with acetone or toluene; grind for 5 minutes until fully mixed, and then dry to obtain a mixture.

[0085] S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread 0.1 part by weight of carbon fiber on the top, put the crucible into a microwave device, set the power to 400 W and the time to 20 s, and collect the product after 1 microwave radiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

[0086] Example 6

[0087] This example provides a method for preparing an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, and this preparation includes the following steps:

[0088] S1. Preparation of heteroatom-doped porous MXene material, including the following steps:

[0089] S11. Preparation of porous MXene nanosheet solution: Take 30 parts by weight of Ti3C2T x nanosheets and stir and disperse them into 300 parts by weight of a hydrogen peroxide (H2O2) solution with a mass concentration of 0.01%. Stir and etch at 20 °C for 10 minutes, and then centrifuge and wash the reacted solution and ultrasonically disperse it to obtain a porous MXene nanosheet solution.

[0090] S12. Preparation of heteroatom dispersion: Take 100 parts by weight of phosphoric acid with a concentration of 1%, and the phosphorus source can be replaced with sodium hypophosphite, hexafluorophosphoric acid, or ammonium dihydrogen phosphate; 100 parts by weight of nitric acid with a concentration of 1%, and the nitrogen source can be replaced with ammonium sulfate, urea, or 1-butyl-3-methylimidazolium tetrafluoroborate; add 200 parts by weight of deionized water and stir well to obtain a heteroatom dispersion.

[0091] S13. Preparation of precursor material: Add the porous MXene nanosheet solution obtained in S11 to the heteroatom dispersion obtained in S12, stir well until evenly mixed, then centrifuge and dry the mixture to obtain the precursor material.

[0092] S14. Preparation of heteroatom-doped porous MXene material: Place the precursor material in a corundum crucible, then transfer it to a tube furnace. In an argon protective atmosphere, heat it to 200 °C at a heating rate of 3 °C / min. After holding for 1 hour, naturally cool it to room temperature, and collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material.

[0093] S2: Preparation of in-situ grown carbon nanotube composite MXene material, including the following steps:

[0094] S21. Take 10 parts by weight of ferrocene and 20 parts by weight of the heteroatom-doped porous MXene material prepared above and place them in a mortar. Add 0.3 parts by weight of toluene, which can be replaced with acetone or dimethyl sulfoxide; grind for 5 minutes until evenly mixed, and then dry to obtain a mixture.

[0095] S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread 0.1 part by weight of carbon fiber on the top, put the crucible into a microwave device, set the power to 400 W and the time to 20 s, and collect the product after 1 microwave radiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

[0096] Example 7

[0097] This example provides a method for preparing an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, and the preparation includes the following steps:

[0098] S1. Preparation of heteroatom-doped porous MXene material, including the following steps:

[0099] S11. Preparation of porous MXene nanosheet solution: Take 30 parts by weight of Ti3C2T x Nanosheets are stirred and dispersed in 300 parts by weight of a hydrogen peroxide (H2O2) solution with a mass concentration of 0.01%, stirred and etched at 20 °C for 10 minutes, and then the reaction solution is centrifuged, washed, and ultrasonically dispersed to obtain a porous MXene nanosheet solution.

[0100] S12. Preparation of heteroatom dispersion: Take 100 parts by weight of boric acid with a concentration of 1%, and the boron source can be replaced with sodium borohydride, B2H6; 100 parts by weight of nitric acid with a concentration of 1%, and the nitrogen source can be replaced with ammonium sulfate, urea, 1-butyl-3-methylimidazolium tetrafluoroborate; add 200 parts by weight of deionized water, and stir well to obtain a heteroatom dispersion.

[0101] S13. Preparation of precursor material: Add the porous MXene nanosheet solution obtained in S11 to the heteroatom dispersion obtained in S12, stir well until evenly mixed, then centrifuge and dry the mixture to obtain the precursor material.

[0102] S14. Preparation of heteroatom-doped porous MXene material: Place the precursor material in a corundum crucible, then transfer it to a tube furnace. Under a nitrogen protection atmosphere, heat it to 200 °C at a heating rate of 3 °C / min. After holding for 1 hour, cool it naturally to room temperature, and collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material.

[0103] S2: Preparation of in-situ grown carbon nanotube composite MXene material, including the following steps:

[0104] S21. Take 10 parts by weight of ferrocene and 20 parts by weight of the heteroatom-doped porous MXene material prepared above and place them in a mortar. Add 0.3 parts by weight of acetone, which can be replaced by toluene or dimethyl sulfoxide; grind for 5 minutes until fully mixed, and then dry to obtain a mixture.

[0105] S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread 0.1 part by weight of carbon fiber on the top, put the crucible into a microwave device, set the power to 400 W and the time to 20 s, and collect the product after 1 microwave radiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

[0106] Those skilled in the art will readily think of other embodiments of this application after considering the specification and the content disclosed herein. This application aims to cover any variations, uses, or adaptations of this application, and these variations, uses, or adaptations follow the general principles of this application and include common general knowledge or conventional technical means in the technical field not disclosed in this application. The specification and examples are only regarded as exemplary, and the true scope and spirit of this application are pointed out by the claims.

[0107] It should be understood that this application is not limited to the precise structure described above and can be modified and changed without departing from its scope. The scope of this application is only limited by the appended claims.

Claims

1. A preparation method of an in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, characterized in that, The heteroatom-doped porous MXene material is composed of porous MXene nanosheets and heteroatoms doped in the porous MXene nanosheets, and carbon nanotubes are in-situ grown on the surface of the heteroatom-doped porous MXene material; the heteroatoms are N, B, and P, and the molar ratio of heteroatoms to porous MXene nanosheets is (1:10) to (1:1), where the molar ratio of B:N:P is 1:2:3; The preparation method includes the following steps: S1: Prepare the heteroatom-doped porous MXene material, including the following steps: S11. Preparation of the porous MXene nanosheet solution: Take MXene nanosheets, stir and disperse them in a hydrogen peroxide solution, stir and etch, and then centrifuge and wash the reacted solution, and ultrasonically disperse it to obtain a porous MXene nanosheet solution; the mass ratio of the MXene nanosheets to the hydrogen peroxide solution is 0.1 to 1, and the mass concentration of the hydrogen peroxide solution is 0.01% to 0.1%; the etching temperature is 20 to 80 °C, and the etching time is 10 to 100 min; S12. Preparation of the heteroatom dispersion: Add a nitrogen source, a boron source, and a phosphorus source to a dispersant, and stir well to make them evenly dispersed to obtain a heteroatom dispersion; S13. Preparation of the precursor material: Add the porous MXene nanosheet solution prepared in S11 to the heteroatom dispersion prepared in S12, stir well until evenly mixed, then centrifuge and dry the mixture to obtain a precursor material; S14. Preparation of the heteroatom-doped porous MXene material: Put the precursor material into a corundum crucible, then transfer it to a tubular furnace, heat it at a certain heating rate in a protective atmosphere, keep it warm, and naturally cool to room temperature, and collect the solid in the corundum crucible to obtain the heteroatom-doped porous MXene material; S2: Prepare the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material, including the following steps: S21. Take ferrocene and the heteroatom-doped porous MXene material prepared in S1, place them in a mortar, add an organic dispersant, grind until fully mixed, and then dry to obtain a mixture; S22. Place the mixture prepared in S21 in a corundum crucible, evenly spread an ignition agent on the top, put the crucible into a microwave device, and collect the product after microwave radiation to obtain the in-situ grown carbon nanotube composite heteroatom-doped porous MXene material.

2. The preparation method according to claim 1, characterized in that: The nitrogen source is selected from one or more of ammonium sulfate, nitric acid, urea, and 1-butyl-3-methylimidazolium tetrafluoroborate; the boron source is selected from one or more of sodium borohydride, boric acid, and B2H6; the phosphorus source is selected from one or more of phosphoric acid, sodium hypophosphite, hexafluorophosphoric acid, and ammonium dihydrogen phosphate.

3. The preparation method according to claim 1, characterized in that: The dispersant is selected from one or more of deionized water and ethanol; the protective atmosphere is any one or more of argon and nitrogen.

4. The preparation method according to claim 1, characterized in that: The ferrocene is bis(cyclopentadienyl)iron, and the mass ratio of ferrocene to the heteroatom-doped porous MXene material is (0.5:1) to (1.5:1).

5. The preparation method according to claim 4, characterized in that: The mass ratio of ferrocene to the heteroatom-doped porous MXene material is 1:

1.

6. The preparation method according to claim 1, characterized in that: The organic dispersant is one or more of toluene, acetone, and dimethyl sulfoxide; the mass ratio of the amount of the organic dispersant to the total amount of ferrocene and heteroatom-doped porous MXene material is (1:100) to (1:20).

7. The preparation method according to claim 1, characterized in that: The ignition agent is selected from one or two of carbon powder or carbon fiber; the mass ratio of the ignition agent to the mixture is (1:300) to (1:100).

8. The preparation method according to claim 1, characterized in that: The power of the microwave device is 400 - 1500 W; the time of each microwave radiation is 20 s - 80 s; the number of microwave radiation times is 1 - 5 times.

9. The preparation method according to claim 8, characterized in that: The power of the microwave device is 900 W; the time of each microwave radiation is 40 s; the number of microwave radiation times is 3 times.

10. The preparation method according to claim 1, characterized in that: in In S14, it is heated to 200 - 500 °C at a heating rate of 3 - 6 °C / min; after holding for 1 - 5 hours, it is naturally cooled to room temperature.

11. According to the preparation method described in claim 1, characterized in that: The porous MXene nanosheets are ceramic materials with a porous two-dimensional sheet structure, and the chemical formula is Ti3C2T x .