Preparation apparatus and method of catalyst nanoparticles, single-walled carbon nanotubes, and their large-scale synthesis apparatus and method

Abstract

The present invention discloses a preparation device and method for catalyst nanoparticles, a single-walled carbon nanotube, and a macroscale synthesis device and method thereof. The device is composed of a catalyst preparation unit, a growth unit, and a product collection unit. The catalyst preparation unit integrates a microplasma reactor, a catalyst and coagulant carrier gas preheater, a conveyor, and an evaporator to form an efficient and precise catalyst preparation. By using a preheated argon gas flow, a continuous-flow microplasma, a preheated sheath gas mixture curtain, and a carbon source mixture curtain, a multi-step chemical vapor process is used to finely regulate the structure of the iron catalyst, and successfully achieve the concentrated generation of iron nanoparticle streams with a narrow size distribution of ~1.5 nm and ~3.5 nm under high volume concentration nanoparticle conditions. Using these iron nanoparticles, single-walled carbon nanotubes with high crystallinity and narrow diameter distribution can be synthesized, and macroscale synthesis of kilograms per day can be achieved.

Description

Technical Field

[0001] The present invention particularly relates to a preparation device and method for catalyst nanoparticles, a single-walled carbon nanotube, and a macroscale synthesis device and method thereof, belonging to the technical field of nanomaterial preparation. Background Art

[0002] Single-walled carbon nanotubes (SWCNTs) have unique morphological, physical, and mechanical properties such as high aspect ratio and high flexibility, making them high-performance conductive and reinforcing materials. Single-walled carbon nanotubes establish a strong and long-range conductive network structure between active material particles, which becomes a key feature for improving the performance of lithium batteries, such as improving cycle life, rate performance, and cohesion between active materials. This is particularly important for silicon-containing anode systems with high volume expansion. Single-walled carbon nanotubes can greatly alleviate the degradation problem and effectively contribute to the industrial application of silicon as a high-capacity anode active material. However, how to achieve the macroscale preparation of SWCNTs has always been a key factor restricting its development.

[0003] Floating chemical vapor deposition (FCCVD) is a common method for synthesizing single-walled carbon nanotubes. A solution of a catalyst precursor and a hydrocarbon is fed into a heated reaction vessel. The catalyst precursor is decomposed by heating and enters a temperature zone suitable for hydrocarbon decomposition with the carrier gas, where nucleation and growth of carbon nanotubes occur. However, it has been difficult to break through the production level of kilograms per day. By reducing the concentration of the catalyst in the catalyst precursor solution, Jung et al. could obtain highly crystalline SWCNTs with a G / D ratio of 62.5, but the yield would be sacrificed. High yield and size uniformity are obstacles that are difficult to overcome simultaneously, and the amount of the product is difficult to exceed the level of hundreds of grams per day (Chemical Engineering Journal 228 (2013) 1050-1056). Mordkovich et al. increased the diameter of the reaction zone to 324 mm and the length of the reaction zone to 5 m by expanding the volume of the reactor to extend the reaction time. Although the reaction space and time required for the catalyst were increased, the highest initial product yield was 72 g / day, and the purity was between 25% and 50%, still far from the level of kilograms per day (Diamond&RelatedMaterials 83 (2018) 15-20). The reason is that FCCVD cannot obtain nano-catalyst particles with a high enough concentration and a narrow size distribution, so it is difficult to form a large-scale preparation of single-walled carbon nanotubes. This is also the core factor that makes it difficult to achieve a ton-level preparation of single-walled carbon nanotubes (Diamond&Related Materials 83 (2018) 15-20, Materials Today:Proceedings 5 (2018) 25951-25955, Carbon 146 (2019) 789-812). Sawyer et al. used a customized microplasma reactor to evaporate iron nanoparticles with a narrow size distribution of 3 nm (Journal of AerosolScience 161 (2022) 105915). Although it was shown that microplasma could effectively produce small-sized nanoparticles, there are still problems in obtaining a high concentration. Summary of the Invention

[0004] The main object of the present invention is to provide a device and method for preparing catalyst nanoparticles, a single-walled carbon nanotube, and a large-scale synthesis device and method thereof, so as to overcome the deficiencies in the prior art.

[0005] To achieve the foregoing invention object, the technical solutions adopted by the present invention include:

[0006] In the first aspect of an embodiment of the present invention, a method for preparing catalyst nanoparticles with a high volume concentration and a narrow diameter distribution is provided, which includes:

[0007] Introduce a catalyst and an anti-caking agent into an evaporator, and mix and evaporate the catalyst and the anti-caking agent in the evaporator to form a precursor vapor of the catalyst;

[0008] Introduce the precursor vapor of the catalyst into a micro-plasma reactor for ionization to form a first catalyst nanoparticle stream, and transport the first catalyst nanoparticle stream to a reaction chamber with a second temperature at a first flow rate;

[0009] Input a sheath mixing gas into the reaction chamber, and make the sheath mixing gas surround the first catalyst nanoparticle stream and maintain a second flow rate. The catalyst nanoparticles in the first catalyst nanoparticle stream are reduced or oxidized by the sheath mixing gas. The sheath mixing gas quickly diffuses into the central region of the first catalyst nanoparticle stream and prevents the collision and aggregation of catalyst nanoparticles, thereby obtaining a second catalyst nanoparticle stream. The particle size distribution range of the catalyst nanoparticles contained in the second catalyst nanoparticle stream is smaller than that of the catalyst nanoparticles contained in the first catalyst nanoparticle stream.

[0010] The second aspect of the embodiments of the present invention provides a method for macroscopically synthesizing single-walled carbon nanotubes with a controllable diameter, which includes:

[0011] Under the condition of the second temperature, make the particle size of the catalyst nanoparticles be 1 nm to 6 nm and the concentration be not less than 2×10 16 cm -3 Mix and react the catalyst nanoparticle stream with a carbon source mixed gas within 1 millisecond to 10 milliseconds to obtain single-walled carbon nanotubes with a controllable diameter.

[0012] The third aspect of the embodiments of the present invention provides a single-walled carbon nanotube, which is obtained by the method for macroscopically synthesizing single-walled carbon nanotubes with a controllable diameter.

[0013] The fourth aspect of the embodiments of the present invention provides a device for preparing catalyst nanoparticles with a high volume concentration and a narrow diameter distribution, which includes:

[0014] A catalyst supply mechanism, an anti-caking agent supply mechanism, an evaporator, a micro-plasma generator, a sheath gas mixture supply mechanism, and a reaction mechanism. The catalyst supply mechanism and the anti-caking agent supply mechanism are respectively connected to the evaporator. The evaporator is connected to the micro-plasma generator. The reaction mechanism has a reaction chamber, a heating mechanism, a catalyst nanoparticle stream injection port communicating with the reaction chamber, and a sheath gas mixture curtain injection port. The sheath gas mixture curtain injection port is arranged around the catalyst nanoparticle stream injection port. The micro-plasma generator is connected to the catalyst nanoparticle stream injection port. The sheath gas mixture supply mechanism is connected to the sheath gas mixture curtain injection port. The heating mechanism is used to maintain the ambient temperature in the reaction chamber at a second temperature;

[0015] The catalyst supply mechanism is used to preheat the catalyst and introduce the catalyst into the evaporator. The anti-caking agent supply mechanism is used to preheat the catalyst and introduce the anti-caking agent into the evaporator. The evaporator is used to evaporate and mix the introduced catalyst and anti-caking agent to form a catalyst precursor vapor. The micro-plasma generator is used to decompose the catalyst precursor vapor to form a first catalyst nanoparticle stream and introduce the first catalyst nanoparticle stream into the reaction chamber. The sheath gas mixture supply mechanism is used to preheat the sheath gas mixture and introduce the sheath gas mixture into the reaction chamber. The sheath gas mixture is distributed around the catalyst nanoparticle stream. And the sheath gas mixture can reduce or oxidize the catalyst nanoparticle stream. And the sheath gas mixture can quickly diffuse to the central region of the catalyst nanoparticle stream and prevent the collision and aggregation of catalyst nanoparticles.

[0016] The fifth aspect of the embodiments of the present invention provides a device for the large-scale synthesis of single-walled carbon nanotubes with a controllable diameter, which includes:

[0017] A catalyst nanoparticle preparation unit, including a catalyst supply mechanism, an anti-caking agent supply mechanism, an evaporator, and a micro-plasma generator. The catalyst supply mechanism and the anti-caking agent supply mechanism are respectively connected to the evaporator. The evaporator is connected to the micro-plasma generator. The catalyst supply mechanism is used to preheat the catalyst and introduce the catalyst into the evaporator. The anti-caking agent supply mechanism is used to preheat the catalyst and introduce the anti-caking agent into the evaporator. The evaporator is used to evaporate and mix the introduced catalyst and anti-caking agent to form a catalyst precursor vapor. The micro-plasma generator is used to decompose the catalyst precursor vapor to form a first catalyst nanoparticle stream and introduce the first catalyst nanoparticle stream into the reaction chamber;

[0018] The reaction unit includes a carbon source mixed gas supply mechanism, a sheath mixed gas supply mechanism, and a reaction mechanism. The reaction mechanism has a reaction chamber, a heating mechanism, a catalyst nanoparticle stream injection port, a sheath mixed gas curtain injection port, and a carbon source mixed gas injection port that communicate with the reaction chamber. The sheath mixed gas curtain injection port is arranged around the catalyst nanoparticle stream injection port. The microplasma generator is connected to the catalyst nanoparticle stream injection port. The sheath mixed gas supply mechanism is connected to the sheath mixed gas curtain injection port. The carbon source mixed gas supply mechanism is connected to the carbon source mixed gas injection port. The heating mechanism is used to maintain the ambient temperature in the reaction chamber at a second temperature. The sheath mixed gas supply mechanism is used to preheat the sheath mixed gas and introduce the sheath mixed gas into the reaction chamber. The carbon source mixed gas supply mechanism is used to preheat the carbon source mixed gas and introduce the carbon source mixed gas into the reaction chamber. The sheath mixed gas surrounds the catalyst nanoparticle stream distribution. Moreover, the sheath mixed gas can reduce or oxidize the catalyst nanoparticle stream. And the sheath mixed gas can quickly diffuse to the central region of the catalyst nanoparticle stream and prevent the collision and aggregation between catalyst nanoparticles.

[0019] Compared with the prior art, the advantages of the present invention include:

[0020] By adopting a multi-step chemical vapor synthesis process, the present invention has successfully achieved the centralized generation of a catalyst nanoparticle stream with a preferably sized distribution not exceeding 6 nm under the condition of extremely high volume concentration nanoparticles (exceeding 2×10 16 cm -3 ). This innovative breakthrough effectively overcomes the problems faced by highly crystalline single-walled carbon nanotubes in terms of narrow diameter distribution and yield, opening up a new path for the development of related fields.

[0021] The present invention preheats the carrier gas, the sheath mixed gas, and the carbon source mixed gas, which not only reduces the heating load of the reactor, but also avoids the increase in the concentration of catalyst nanoparticles. At the same time, the introduction of the preheated gas also reduces the unnecessary collision between catalyst nanoparticles, thereby effectively suppressing the overgrowth of catalyst nanoparticles and ensuring the uniformity and stability of catalyst nanoparticles.

[0022] By using preheated carrier gas, continuously flowing microplasma, preheated sheath mixed gas curtain, and carbon source mixed gas curtain, and adopting a multi-step chemical vapor process to finely regulate the structure of the iron catalyst, the present invention has successfully achieved the centralized generation of iron nanoparticle streams with narrow size distributions of ~1.5 nm and ~3.5 nm under the condition of high volume concentration nanoparticles (exceeding 2×10 16 cm -3 ). For reference,Figure 10 The statistical results in . Further, using these catalyst nanoparticles, single-walled carbon nanotubes with high crystallinity and narrow diameter distribution (the particle sizes are mainly concentrated in the ranges of 1.13 nm - 1.54 nm and 0.86 nm - 0.94 nm, and the average particle sizes are concentrated at 1.30 nm and 0.91 nm) can be synthesized, and kilogram-level macroscale synthesis per day can be achieved. The present invention shows significant advantages in the macroscale preparation of diameter-controlled single-walled carbon nanotubes, and has great commercial value and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a device for microplasma macroscale synthesis of single-walled carbon nanotubes provided in a typical embodiment of the present invention;

[0024] Figure 2 is a partial cross-sectional view of some catalyst preparation units and growth units provided in a typical embodiment of the present invention;

[0025] Figure 3 is a schematic principle diagram of a device for microplasma macroscale synthesis of single-walled carbon nanotubes provided in a typical embodiment of the present invention;

[0026] Figure 4 Thermogravimetric characterization diagram of single-walled carbon nanotubes prepared by using the device of the present invention in Example 1 of the present invention;

[0027] Figure 5 Scanning electron microscope image of the single-walled carbon nanotubes prepared in Example 3 of the present invention;

[0028] Figure 6 Raman spectrum diagram of the single-walled carbon nanotubes prepared in Example 5 of the present invention;

[0029] Figure 7 Partial Raman spectrum diagram of the RBM characteristic peak of the single-walled carbon nanotubes prepared in Example 5 of the present invention;

[0030] Figure 8 Transmission electron microscope image of the single-walled carbon nanotubes prepared in Example 5 of the present invention;

[0031] Figure 9 Transmission electron microscope image of the single-walled carbon nanotubes prepared in Example 5 of the present invention;

[0032] Figure 10 Statistical results of the diameter distribution of iron nanoparticles and SWCNTs measured by transmission electron microscope for the sample prepared in Example 5 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] In view of the deficiencies in the prior art, through long-term research and a large number of practices, the inventors of this case were able to propose the technical solution of the present invention. The following will further explain the technical solution, its implementation process, principles, etc.

[0034] The first aspect of the embodiment of the present invention provides a method for preparing catalyst nanoparticles with a high volume concentration and a narrow diameter distribution, which includes:

[0035] Introduce a catalyst and an anti-caking agent into an evaporator, and mix and evaporate the catalyst and the anti-caking agent in the evaporator to form a catalyst precursor vapor;

[0036] Introduce the catalyst precursor vapor into a micro-plasma reactor for ionization to form a first catalyst nanoparticle stream, and transport the first catalyst nanoparticle stream to a reaction chamber with a second temperature at a first flow rate;

[0037] Input a sheath mixing gas into the reaction chamber, and make the sheath mixing gas surround the first catalyst nanoparticle stream and maintain a second flow rate. The catalyst nanoparticles in the first catalyst nanoparticle stream are reduced or oxidized by the sheath mixing gas, and the sheath mixing gas quickly diffuses into the central region of the first catalyst nanoparticle stream and prevents the collision and aggregation of catalyst nanoparticles, thereby obtaining a second catalyst nanoparticle stream. The particle size distribution range of the catalyst nanoparticles contained in the second catalyst nanoparticle stream is smaller than the particle size distribution range of the catalyst nanoparticles contained in the first catalyst nanoparticle stream.

[0038] In a more specific embodiment, the method for preparing catalyst nanoparticles with a high volume concentration and a narrow diameter distribution specifically includes:

[0039] Use a carrier gas with a first temperature to introduce a catalyst and an anti-caking agent into the evaporator respectively, and the first temperature is 100°C to 500°C.

[0040] Furthermore, the flow rate of the carrier gas is 0.05 L / min to 15 L / min.

[0041] Furthermore, the carrier gas includes an inert gas, and the inert gas is selected from at least one of argon, nitrogen, and helium, and preferably argon.

[0042] Furthermore, the first flow rate is greater than 5 m / s.

[0043] Furthermore, the first flow rate is 5 m / s to 12 m / s.

[0044] Furthermore, the second temperature is 800°C to 1800°C.

[0045] Further, the volume concentration of the catalyst precursor vapor is 3×10 15 cm -3 ~9×10 18 cm -3 。

[0046] Further, the particle size of the catalyst precursor particles contained in the catalyst precursor vapor is 1 nm to 600 nm.

[0047] In a more specific embodiment, the method for preparing catalyst nanoparticles with a high volume concentration and a narrow diameter distribution specifically includes:

[0048] First, preheat the sheath mixed gas to a third temperature, and then input the sheath mixed gas into the reaction chamber.

[0049] Further, the third temperature is 300 °C to 1200 °C.

[0050] Further, the second flow rate is 3 m / s to 90 m / s.

[0051] Further, the particle size of the catalyst nanoparticles in the first catalyst nanoparticle stream is 1 nm to 12 nm, and the concentration is not less than 2×10 16 cm -3 , and the particle size of the catalyst nanoparticles in the second catalyst nanoparticle stream is 1 nm to 6 nm, and the concentration is not less than 2×10 16 cm -3 。

[0052] Further, the concentration of the catalyst nanoparticles in the first catalyst nanoparticle stream is 2×10 16 cm -3 ~9×10 20 cm -3 , and the concentration of the catalyst nanoparticles in the second catalyst nanoparticle stream is 2×10 16 cm -3 ~9×10 22 cm -3 。

[0053] Further, the particle size of the catalyst nanoparticles in the second catalyst nanoparticle stream is concentrated in the range of 1 nm to 2 nm and 3.2 nm to 4 nm. Further still, the average particle size of the catalyst nanoparticles in the second catalyst nanoparticle stream is 1.5 nm and 3.5 nm.

[0054] Further, the catalyst includes an iron-containing organic substance, the coagulation inhibitor includes a sulfur element-containing compound or mixture, and the sheath mixed gas includes a reducing gas and water vapor or oxygen. Among them, the reducing gas in the sheath mixed gas has a reducing effect on the one hand. On the other hand, the reducing gas also has a synergistic effect with water vapor or oxygen, and has the functions of oxidation, reduction and etching. It can etch the catalyst nanoparticles in the first catalyst nanoparticle stream, so that the particle size of the catalyst nanoparticles becomes smaller. At the same time, it prevents the catalyst nanoparticles in the first catalyst nanoparticle stream from further colliding and growing, and removes the amorphous carbon in the first catalyst nanoparticle stream, thereby improving the purity of the product.

[0055] Further, the molar ratio of the iron element in the catalyst to the sulfur element in the flocculant is 2:1 to 60:1.

[0056] Further, the catalyst includes ferrocene and the like.

[0057] Further, the coagulation inhibitor includes at least one or a combination of two or more of thiophene, dimethyl sulfoxide, sulfur powder, hydrogen sulfide, sulfur dioxide, but is not limited thereto.

[0058] Further, the reducing gas in the sheath mixed gas includes at least one of hydrogen, carbon monoxide, ammonia, but is not limited thereto.

[0059] Further, the volume ratio of the reducing gas to the water vapor or the oxygen is 10:1 to 90:1.

[0060] The second aspect of the embodiments of the present invention provides a method for macroscopically synthesizing single-walled carbon nanotubes with a controllable diameter, which includes:

[0061] Under the second temperature condition, a catalyst nanoparticle stream with a particle size of 1 nm to 6 nm and a concentration of not less than 2×10 16 cm -3 is mixed and reacted with a carbon source mixed gas within 1 millisecond to 10 milliseconds, thereby obtaining single-walled carbon nanotubes with a controllable diameter.

[0062] Further, the concentration of the catalyst nanoparticles in the catalyst nanoparticle stream is 2×10 16 cm -3 ~9×10 22 cm -3 .

[0063] Further, the catalyst nanoparticle stream is a second catalyst nanoparticle stream formed by the method for preparing catalyst nanoparticles with a high volume concentration and a narrow diameter distribution.

[0064] In a more specific embodiment, the method for macroscopically synthesizing single-walled carbon nanotubes with a controllable diameter specifically includes:

[0065] Forming the catalyst nanoparticle stream by using the method for preparing catalyst nanoparticles with a high volume concentration and a narrow diameter distribution;

[0066] Introducing a carbon source mixed gas with a fourth temperature into the reaction chamber, keeping the carbon source mixed gas at a third flow rate, and causing the carbon source mixed gas and the catalyst nanoparticle stream to undergo a mixing reaction within 1 millisecond to 10 milliseconds.

[0067] In a more specific embodiment, the method for macroscopically synthesizing single-walled carbon nanotubes with a controllable diameter specifically includes:

[0068] Preheating the carbon source mixed gas to the fourth temperature first, and then inputting the carbon source mixed gas into the reaction chamber.

[0069] Furthermore, the fourth temperature is 230°C to 650°C.

[0070] Furthermore, the third flow rate is 3 m / s to 90 m / s.

[0071] Furthermore, the carbon source mixed gas includes a carbon source gas and a reducing gas.

[0072] Furthermore, the volume ratio of the carbon source gas to the reducing gas is 1:(1 to 50).

[0073] Furthermore, the flow rate ratio of the carbon source gas contained in the carbon source mixed gas to the reducing gas contained in the sheath mixed gas is 1:(2 to 35).

[0074] Furthermore, the carbon source gas includes at least one of natural gas, methane, ethane, propane, butane, pentane, hexane, ethylene, propylene, ethanol, anthracene, or anthracene oil vapor, but is not limited thereto.

[0075] Furthermore, the reducing gas contained in the carbon source mixed gas includes at least one of hydrogen, carbon monoxide, and ammonia, but is not limited thereto.

[0076] The third aspect of the embodiments of the present invention provides a single-walled carbon nanotube, which is obtained by the method for macroscopically synthesizing single-walled carbon nanotubes with a controllable diameter.

[0077] Furthermore, the G / D ratio of the single-walled carbon nanotube exceeds 50.

[0078] Further, the diameters of the single-walled carbon nanotubes are mainly concentrated in the range of 1.13 nm to 1.54 nm and 0.86 nm to 0.94 nm, and the average diameters are mainly concentrated at 1.30 nm or 0.91 nm.

[0079] The fourth aspect of the embodiments of the present invention provides a device for preparing catalyst nanoparticles with a high volume concentration and a narrow diameter distribution, which includes:

[0080] A catalyst supply mechanism, an anti-caking agent supply mechanism, an evaporator, a micro-plasma generator, a sheath gas supply mechanism, and a reaction mechanism. The catalyst supply mechanism and the anti-caking agent supply mechanism are respectively connected to the evaporator. The evaporator is connected to the micro-plasma generator. The reaction mechanism has a reaction chamber, a heating mechanism, a catalyst nanoparticle stream inlet communicating with the reaction chamber, and a sheath gas curtain inlet. The sheath gas curtain inlet is arranged around the catalyst nanoparticle stream inlet. The micro-plasma generator is connected to the catalyst nanoparticle stream inlet. The sheath gas supply mechanism is connected to the sheath gas curtain inlet. The heating mechanism is used to maintain the ambient temperature in the reaction chamber at a second temperature;

[0081] The catalyst supply mechanism is used to preheat the catalyst and introduce the catalyst into the evaporator. The anti-caking agent supply mechanism is used to preheat the catalyst and introduce the anti-caking agent into the evaporator. The evaporator is used to evaporate and mix the introduced catalyst and anti-caking agent to form a catalyst precursor vapor. The micro-plasma generator is used to decompose the catalyst precursor vapor to form a first catalyst nanoparticle stream and introduce the first catalyst nanoparticle stream into the reaction chamber. The sheath gas supply mechanism is used to preheat the sheath gas and introduce the sheath gas into the reaction chamber. The sheath gas is distributed around the catalyst nanoparticle stream. Moreover, the sheath gas can reduce or oxidize the catalyst nanoparticle stream, and the sheath gas can quickly diffuse to the central region of the catalyst nanoparticle stream and prevent the collision and aggregation of catalyst nanoparticles.

[0082] Further, the catalyst supply mechanism includes a catalyst carrier gas preheater and a catalyst transporter, which are connected in sequence. The catalyst transporter is connected to the evaporator. The anti-caking agent supply mechanism includes an anti-caking agent carrier gas preheater and an anti-caking agent transporter, which are connected in sequence. The anti-caking agent transporter is connected to the evaporator.

[0083] The fifth aspect of the embodiments of the present invention provides a device for macroscopically synthesizing single-walled carbon nanotubes with a controllable diameter, which includes:

[0084] A catalyst nanoparticle preparation unit, including a catalyst supply mechanism, an anti-caking agent supply mechanism, an evaporator, and a micro-plasma generator. The catalyst supply mechanism and the anti-caking agent supply mechanism are respectively connected to the evaporator, and the evaporator is connected to the micro-plasma generator. The catalyst supply mechanism is used to preheat the catalyst and introduce the catalyst into the evaporator. The anti-caking agent supply mechanism is used to preheat the catalyst and introduce the anti-caking agent into the evaporator. The evaporator is used to evaporate and mix the introduced catalyst and anti-caking agent to form a catalyst precursor vapor. The micro-plasma generator is used to decompose the catalyst precursor vapor to form a first catalyst nanoparticle stream and introduce the first catalyst nanoparticle stream into the reaction chamber;

[0085] A reaction unit, including a carbon source mixed gas supply mechanism, a sheath mixed gas supply mechanism, and a reaction mechanism. The reaction mechanism has a reaction chamber, a heating mechanism, and a catalyst nanoparticle stream injection port, a sheath mixed gas curtain injection port, and a carbon source mixed gas injection port that communicate with the reaction chamber. The sheath mixed gas curtain injection port is arranged around the catalyst nanoparticle stream injection port. The micro-plasma generator is connected to the catalyst nanoparticle stream injection port. The sheath mixed gas supply mechanism is connected to the sheath mixed gas curtain injection port. The carbon source mixed gas supply mechanism is connected to the carbon source mixed gas injection port. The heating mechanism is used to maintain the ambient temperature in the reaction chamber at a second temperature. The sheath mixed gas supply mechanism is used to preheat the sheath mixed gas and introduce the sheath mixed gas into the reaction chamber. The carbon source mixed gas supply mechanism is used to preheat the carbon source mixed gas and introduce the carbon source mixed gas into the reaction chamber. The sheath mixed gas is distributed around the catalyst nanoparticle stream, and the sheath mixed gas can reduce or oxidize the catalyst nanoparticle stream, and the sheath mixed gas can quickly diffuse to the central region of the catalyst nanoparticle stream and prevent the collision and aggregation of catalyst nanoparticles.

[0086] Further, the catalyst supply mechanism includes a catalyst carrier gas preheater and a catalyst transporter, which are connected in sequence. The catalyst transporter is connected to the evaporator. The anti-caking agent supply mechanism includes an anti-caking agent carrier gas preheater and an anti-caking agent transporter, which are connected in sequence. The anti-caking agent transporter is connected to the evaporator.

[0087] Further, the apparatus for the macroscale synthesis of single-walled carbon nanotubes with a controllable diameter further includes: a product collection unit, which is connected to the reaction chamber and is used for gas-solid separation of the generated single-walled carbon nanotubes and enabling continuous collection.

[0088] The technical solution, its implementation process and principle, etc. will be further explained below in conjunction with the accompanying drawings and specific implementation cases. Unless otherwise specified, the functional devices and processes, etc. adopted in the embodiments of the present invention are all known in the art.

[0089] In a relatively typical implementation, please refer to Figure 1 and Figure 2 , an apparatus for the macroscale synthesis of single-walled carbon nanotubes by microplasma, including a catalyst preparation unit 110, a reaction unit 220, and a collection unit 330. The product collection unit 330 is connected to one end of the growth unit 220, and the other end of the growth unit 220 is connected to the catalyst preparation unit 110. Among them, the catalyst preparation unit 110 is mainly used to synthesize a first catalyst nanoparticle stream with a particle size of 1 nm to 12 nm and a concentration of not less than 2×10 16 cm -3 . The reaction unit 220 is mainly used to provide the temperature and space required for synthesizing a catalyst nanoparticle stream with a high concentration and a narrow diameter distribution (i.e., the second catalyst nanoparticle stream), and the temperature and space required for the growth of highly crystalline single-walled carbon nanotubes, so as to form a second catalyst nanoparticle stream with a particle size of 1 nm to 6 nm and a concentration of not less than 2×10 16 cm -3 from the first catalyst nanoparticle stream, and to react the second catalyst nanoparticle stream with the carbon source mixed gas to macroscale synthesize single-walled carbon nanotubes. The collection unit 330 is used to collect the synthesized single-walled carbon nanotubes.

[0090] Specifically, the catalyst preparation unit 110 includes a catalyst carrier gas preheater 111, an anti-congealer carrier gas preheater 112, two conveyors 115, an evaporator 117, and a microplasma reactor 120. The catalyst carrier gas preheater 111 and the anti-congealer carrier gas preheater 112 are respectively connected to the evaporator 117 via a conveyor 115, and the evaporator 117 is also connected to the microplasma reactor 120. The growth unit 220 includes a high-temperature growth tube 211, a sheath mixed gas curtain injection port 223, and a carbon source mixed gas curtain injection port 225. There is a reaction chamber inside the high-temperature growth tube 211. Both the sheath mixed gas curtain injection port 223 and the carbon source mixed gas curtain injection port 225 are connected to the reaction chamber. The microplasma generator 120 is connected to the high-temperature growth tube 211. The sheath mixed gas curtain injection port 223 is coaxially arranged with the microplasma generator 120. One end of the microplasma generator 120 is inserted into the high-temperature growth tube 211, and the other end is connected to the evaporator 117. The product collection unit 300 includes a collection chamber 331, a transition chamber 333, and an exhaust port 335. The collection chamber 331 is respectively connected to the transition chamber 333, the exhaust port 335, and the growth chamber inside the high-temperature growth tube 211.

[0091] It should be noted that the catalyst carrier gas preheater 111, the anti-congealer carrier gas preheater 112, the two conveyors 115, the evaporator 117, and the microplasma reactor 120 used in the present invention are all functional devices known in the art, and they can all be obtained through commercial purchase or custom processing known in the art. The specific structures and product models thereof are not limited herein. Exemplarily, the microplasma reactor 120 includes a power supply, an inner electrode, a hollow alumina tube, and a coiled outer electrode. The coiled outer electrode is coiled around the hollow alumina tube. The inner electrode is embedded inside the hollow alumina tube. The inner electrode is a tungsten rod with a diameter of 0.15 mm to 0.6 mm. The coiled outer electrode is a tantalum wire with a diameter of 0.10 mm to 0.6 mm. The coiled outer electrode is wound around the hollow alumina tube for 8 to 30 turns. The power supply parameters are a 10 W to 160 W, 350 MHz to 550 MHz ultra-high frequency power supply. The heating method of the growth tube 221 can be one or more of electric heating, induction heating, and arc heating.

[0092] In a relatively typical embodiment, a method for preparing macroscopically diameter-controllable single-walled carbon nanotubes using a device for microplasma macroscale synthesis of single-walled carbon nanotubes may include the following steps:

[0093] S1) Place the catalyst and the coagulation inhibitor in a conveyor 115 respectively, and introduce an inert gas to evacuate the entire device; preheat the carrier gas, the sheath mixed gas, and the carbon source mixed gas with a catalyst carrier gas preheater 111, a coagulation inhibitor carrier gas preheater 112, a sheath mixed gas preheater, and a carbon source mixed gas preheater respectively, so as to preheat the temperatures of the carrier gas, the sheath mixed gas, and the carbon source mixed gas to 100°C to 500°C, 300°C to 1200°C, and 230°C to 650°C respectively.

[0094] The catalyst is an iron-containing organic substance, and the coagulation inhibitor contains a sulfur element compound or mixture, where the molar ratio of iron to sulfur element is 2:1 to 60:1. Exemplarily, the catalyst is ferrocene; the coagulation inhibitor is thiophene, dimethyl sulfoxide, sulfur powder, hydrogen sulfide, sulfur dioxide, or other sulfur-containing compounds or mixtures; specifically, the carrier gas is argon, and the flow rate of the carrier gas is 0.05 L / min to 15 L / min; the sheath mixed gas contains a reducing gas and other gases, and the inlet flow rate of the sheath mixed gas is 3 m / s to 90 m / s; the flow rate ratio of the carbon source gas to the reducing gas in the carbon source mixed gas is 1:(2 to 35), and the inlet flow rate of the carbon source mixed gas is 3 m / s to 90 m / s.

[0095] S2) Heat the temperature of the reaction chamber in the high-temperature growth tube 211 to 620°C to 3200°C to form a high-temperature reaction zone with a stable temperature field in the reaction chamber. At the same time, start the micro-plasma generator 120, and set the power of the micro-plasma generator 120 to 10 W to 160 W and the frequency to 350 MHz to 550 MHz;

[0096] S3) The preheated carrier gas transports the catalyst and the coagulation inhibitor in the two conveyors 115 to the evaporator 117 for evaporation according to a mass ratio of 2:1 to 60:1, forming a catalyst precursor vapor with a volume concentration of 3×10 15 cm -3 ~9×10 18 cm -3 cm -3 and a particle size of 1 nm to 600 nm. The catalyst precursor vapor is ionized by the micro-plasma generator 120 to form a particle size of 1 nm to 12 nm and a concentration of 2×10 16 cm -3 ~9×10 20 cm -3The first catalyst nanoparticle stream. The first catalyst nanoparticle stream ejected from the microplasma generator 120 interacts with the sheath mixed gas in the reaction chamber at a flow rate greater than 5 m / s. The catalyst nanoparticle stream is reduced or mildly oxidized by the sheath mixed gas. At the same time, the sheath mixed gas quickly diffuses to the center of the first catalyst nanoparticle stream, preventing further collision and aggregation of the catalyst nanoparticles, and forming a second catalyst nanoparticle stream with a particle size of 1 nm to 6 nm and a concentration of 2×10 16 cm -3 ~9×10 22 cm -3 ;

[0097] Immediately afterwards, the preheated carbon source mixed gas is introduced into the reaction chamber, and the carbon source mixed gas reacts with the catalyst nanoparticles within 6 milliseconds, thereby realizing high-crystalline single-walled carbon nanotubes (SWCNTs) with a controllable diameter.

[0098] S4) Separate and collect the products generated in the reaction chamber through the collection unit 330, and realize continuous collection through the transition chamber 333 to obtain the initial product.

[0099] The G / D ratio of the single-walled carbon nanotubes prepared by the present invention exceeds 50. The controllable diameters of the high-crystalline single-walled carbon nanotubes are concentrated in the ranges of 1.13 nm to 1.54 nm and 0.86 nm to 0.94 nm, and the average diameters are concentrated at 1.30 nm and 0.91 nm, and its production capacity can reach kilograms per day.

[0100] Specifically, taking ferrocene as an example of the catalyst, the process of forming ferrocene nanoparticles from ferrocene vapor in the microplasma reactor can be subdivided into the following three stages, which can be referred to Figure 3 as shown:

[0101] Introduction and preheating stage: The preheated argon gas carries the vapors of ferrocene and the anti-caking agent (sulfur) and is introduced into the microplasma under high-temperature conditions. This step provides the necessary initial conditions and energy for subsequent chemical reactions.

[0102] Dissociation and initial formation stage: In the high-temperature environment of the microplasma reactor, ferrocene rapidly dissociates into cyclopentadienyl (Cp) and Fe atomic vapor. At the same time, sulfur atomic vapor also participates in the reaction. During this process, a small part of argon and Fe atoms are ionized by the microplasma. Due to the residence time in the microplasma being no more than 6 ms, the collision opportunities between Fe atomic vapor are relatively few. At the same time, part of the sulfur atoms aggregate around the iron atoms, effectively inhibiting the excessive growth of iron atoms. At the outlet of the microplasma generator, the vast majority of Fe atoms (more than 99%) still remain in the gas phase, while only less than 1% of Fe forms small clusters with n = 2 to n = 6. As the gas flow enters the downstream of the microplasma generator, the collisions between iron atomic vapor and iron clusters gradually increase, and larger particles begin to form. Outside the microplasma environment, the charge is conserved during the collision process between particles, and the total charge in the Fe particle group also remains stable. Due to the electrostatic enhancement effect, charged particles grow rapidly, while the growth of neutral particles is relatively slow. In addition, hydrogen in the sheath mixing gas (used for oxidation or etching) further prevents the collision growth of iron nanoparticles, and finally forms iron nanoparticles with a bimodal size distribution (~1.5 nm and ~3.5 nm).

[0103] Growth and stabilization stage: In the final stage of the growth of iron nanoparticles, the charge repulsion mechanism effectively prevents the collision of large particles. As the small neutral particles are completely consumed, the particle size distribution gradually approaches a stable state. At this time, a preheated hydrocarbon gas curtain is introduced and cracked in the high-concentration iron nanoparticles, and then single-walled carbon nanotubes with a bimodal size (average diameters of 1.30 nm and 0.91 nm) and a concentrated distribution are grown.

[0104] This process makes full use of the characteristics of the microplasma reactor. By precisely controlling the reaction conditions and parameters, the efficient synthesis of iron nanoparticles and the concentrated growth of single-walled carbon nanotubes are achieved.

[0105] In the microplasma reactor, the dissociation of ferrocene produces neutral and ionized iron vapor. Electrostatic interaction not only promotes the formation and growth of small particles but also successfully restricts the aggregation of large particles. Due to the residence time in the microplasma reactor being 1 ms to 10 ms, the growth of most large particles mainly occurs at the rear end of the microplasma reactor. When these particles meet the preheated sheath mixing gas curtain at a certain speed, the possibility of their collision growth is further inhibited, thus forming high-concentration iron nanoparticles with a bimodal size distribution, mainly distributed at ~1.5 nm and ~3.5 nm. Subsequently, when these nanoparticles meet the preheated carbon source mixing gas curtain, single-walled carbon nanotubes (SWCNTs) with high crystallinity and a sharp diameter distribution can be grown, with average diameters of 1.30 nm and 0.91 nm respectively, achieving a synthesis efficiency of kilograms per day.

[0106] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0107] Example 1

[0108] This example is implemented with a device for microplasma macroscale synthesis of single-walled carbon nanotubes provided by the present invention. In this example, ferrocene is used as the catalyst, sulfur powder is used as the coagulation inhibitor, argon is used as the carrier gas, hydrogen and water vapor with a volume ratio of 10:1 to 90:1 are used as the sheath mixed gas, and methane and hydrogen with a volume ratio of 1:(1 - 50) are used as the carbon source mixed gas.

[0109] A method for preparing macroscale diameter-controllable single-walled carbon nanotubes includes the following steps:

[0110] Place ferrocene and sulfur powder in a conveyor 115 respectively. The molar ratio of iron and sulfur elements in ferrocene and sulfur powder is 2:1. Introduce an inert gas to evacuate the entire device; preheat the carrier gas argon to 100 °C with a catalyst carrier gas preheater 111 and a coagulation inhibitor carrier gas preheater 112 respectively, and preheat the sheath mixed gas and the carbon source mixed gas to 300 °C and 230 °C with a sheath mixed gas preheater and a carbon source mixed gas preheater respectively. Heat the temperature of the reaction chamber in the high-temperature growth tube 211 to 900 °C to form a high-temperature reaction zone with a stable temperature field in the reaction chamber. At the same time, start the microplasma generator and set the power of the microplasma generator to 15 W and the frequency to 350 MHz.

[0111] Introduce the preheated carrier gas argon into the two conveyors 115 respectively. The flow rate of the carrier gas argon is 1 L / min to transport the ferrocene and sulfur powder in the two conveyors 115 to the evaporator 117 for evaporation, forming catalyst precursor vapor with a particle size of 1 nm - 600 nm and a volume concentration of 3×10 15 cm -3 ~9×10 18 cm -3 The catalyst precursor vapor is ionized by the microplasma generator 120 to form a first catalyst nanoparticle stream with a particle size of 1 nm - 12 nm and a concentration of 2×10 16 cm -3 ~5×10 17 cm -3 The first catalyst nanoparticle stream ejected from the microplasma generator 120 enters the reaction chamber in the high-temperature growth tube 211 at a flow rate of 6 m / s.

[0112] The preheated sheath mixed gas is input into the reaction chamber from the outer space of the reaction chamber in the high-temperature growth tube 211. The inlet flow rate of the sheath mixed gas is 3 m / s to 90 m / s. In the reaction chamber, the first catalyst nanoparticle stream interacts with the sheath mixed gas. The catalyst nanoparticle stream is reduced or mildly oxidized by the sheath mixed gas. At the same time, the sheath mixed gas will quickly diffuse to the center of the first catalyst nanoparticle stream, preventing further collision and aggregation of the catalyst nanoparticles, and forming a second catalyst nanoparticle stream with a particle size of 1 nm to 6 nm and a concentration of 9×10 16 cm -3 ~8×10 17 cm -3 .

[0113] Immediately afterwards, the preheated carbon source mixed gas is introduced into the reaction chamber. The inlet flow rate of the carbon source mixed gas is 3 m / s. The flow ratio of methane to hydrogen in the carbon source mixed gas is 1:2. And the carbon source mixed gas is reacted with the second catalyst nanoparticles within 10 milliseconds, so as to realize high-crystalline SWCNTs with a controllable diameter.

[0114] The product generated in the reaction chamber is separated and collected by the collection unit 330, and the initial product is continuously collected through the transition chamber 333.

[0115] As can be seen from Table 2, the output of the initial product obtained in Example 1 is 53 g / h. Under the test conditions with an excitation wavelength of 532 nm, after calculation, the G / D ratio of the product is 50.8, that is, the prepared product contains high-quality single-walled carbon nanotubes. Through the classical formula of Equation 1, the particle size distribution of the single-walled carbon nanotubes is concentrated in the range of 0.8 - 1.6 nm. From Figure 4 the thermogravimetric characterization, it can be seen that the TG residue in the product is 33.34 wt%.

[0116] Example 2

[0117] This example is implemented by a device for micro-plasma macroscale synthesis of single-walled carbon nanotubes provided by the present invention. In this example, ferrocene is used as the catalyst, dimethyl sulfoxide is used as the coagulation inhibitor, argon is used as the carrier gas, carbon monoxide and oxygen with a volume ratio of 10:1 to 90:1 are used as the sheath mixed gas, and methane and hydrogen with a volume ratio of 1:(1 - 50) are used as the carbon source mixed gas.

[0118] A method for preparing macroscale diameter-controllable single-walled carbon nanotubes includes the following steps:

[0119] Put ferrocene and dimethyl sulfoxide into a conveyor 115 respectively. The molar ratio of iron and sulfur elements in ferrocene and dimethyl sulfoxide is 9:1. Introduce an inert gas to evacuate the whole device. Preheat the carrier gas argon to 200 °C with the catalyst carrier gas preheater 111 and the anti - condensation agent carrier gas preheater 112 respectively. Preheat the sheath gas mixture and the carbon source gas mixture to 600 °C and 280 °C with the sheath gas mixture preheater and the carbon source gas mixture preheater respectively. Heat the temperature of the reaction chamber in the high - temperature growth tube 211 to 1350 °C to form a high - temperature reaction zone with a stable temperature field in the reaction chamber. At the same time, start the micro - plasma generator and set the power of the micro - plasma generator to 50 W and the frequency to 450 MHz.

[0120] Introduce the preheated carrier gas argon into the two conveyors 115 respectively. The flow rate of the carrier gas argon is 3 L / min to transport the ferrocene and dimethyl sulfoxide in the two conveyors 115 to the evaporator 117 for evaporation, forming catalyst precursor vapor with a particle size of 1 nm - 600 nm and a volume concentration of 3×10 15 cm -3 ~9×10 18 cm -3 The catalyst precursor vapor is ionized by the micro - plasma generator 120 to form a first catalyst nanoparticle stream with a particle size of 1 nm - 10 nm and a concentration of 3×10 16 cm -3 ~8×10 17 cm -3 The first catalyst nanoparticle stream ejected from the micro - plasma generator 120 enters the reaction chamber in the high - temperature growth tube 211 at a flow velocity of 8 m / s.

[0121] Input the preheated sheath gas mixture from the outer space of the reaction chamber in the high - temperature growth tube 211 into the reaction chamber. The inlet flow velocity of the sheath gas mixture is 15 m / s. In the reaction chamber, the first catalyst nanoparticle stream interacts with the sheath gas mixture. The catalyst nanoparticle stream is reduced or mildly oxidized by the sheath gas mixture. At the same time, the sheath gas mixture will quickly diffuse to the center of the first catalyst nanoparticle stream, preventing further collision and aggregation of the catalyst nanoparticles, and forming a second catalyst nanoparticle stream with a particle size of 1 nm - 6 nm and a concentration of 5×10 17 cm -3 ~2×10 18 cm -3

[0122] Subsequently, the preheated carbon source mixed gas is introduced into the reaction chamber. The flow rate of the introduced carbon source mixed gas is 21 m / s, the flow rate ratio of methane to hydrogen in the carbon source mixed gas is 1:15, and the carbon source mixed gas is made to react with the second catalyst nanoparticles within 8 milliseconds, thereby realizing high-crystalline SWCNTs with a controllable diameter.

[0123] The product generated in the reaction chamber is separated and collected through the collection unit 330, and the initial product is continuously collected through the transition chamber 333.

[0124] As can be seen from Table 2, the output of the initial product obtained in Example 2 is 96 g / h, the TG residue in the product is 23.6 wt%, and the G / D ratio of the product is 63.2, that is, the prepared product contains high-quality single-walled carbon nanotubes. Through calculation using the classical formula of Formula 1, the particle size distribution of the single-walled carbon nanotubes is concentrated in the range of 0.8 nm to 1.6 nm.

[0125] Example 3

[0126] This example is implemented with a device for microplasma bulk synthesis of single-walled carbon nanotubes provided by the present invention. In this example, ferrocene is used as the catalyst, thiophene is used as the coagulation inhibitor, argon is used as the carrier gas, hydrogen and oxygen with a volume ratio of 10:1 to 90:1 are used as the sheath mixed gas, and methane and hydrogen with a volume ratio of 1:(1 to 50) are used as the carbon source mixed gas.

[0127] A method for preparing bulk diameter-controllable single-walled carbon nanotubes includes the following steps:

[0128] Ferrocene and thiophene are respectively placed in a conveyor 115. The molar ratio of iron to sulfur elements in ferrocene and thiophene is 20:1, and an inert gas is introduced to evacuate the entire device; the carrier gas argon is preheated to 350 °C by the catalyst carrier gas preheater 111 and the coagulation inhibitor carrier gas preheater 112 respectively, and the sheath mixed gas and the carbon source mixed gas are preheated to 900 °C and 480 °C respectively by the sheath mixed gas preheater and the carbon source mixed gas preheater. The temperature of the reaction chamber in the high-temperature growth tube 211 is heated to 1550 °C to form a high-temperature reaction zone with a stable temperature field in the reaction chamber. At the same time, the microplasma generator is started, and the power of the microplasma generator is set to 90 W and the frequency is set to 480 MHz.

[0129] The preheated carrier gas argon is respectively introduced into the two conveyors 115, and the flow rate of the carrier gas argon is 5 L / min to transport the ferrocene and thiophene located in the two conveyors 115 to the evaporator 117 for evaporation, forming particles with a particle size of 1 nm to 600 nm and a volume concentration of 3×10 15 cm -3 ~9×10 18 cm -3The catalyst precursor vapor passes through the ionization of the micro-plasma generator 120 to form a first catalyst nanoparticle stream with a particle size of 1 nm to 8 nm and a concentration of 7×10 16 cm -3 ~9×10 18 cm -3 ; The first catalyst nanoparticle stream ejected from the micro-plasma generator 120 enters the reaction chamber in the high-temperature growth tube 211 at a flow rate of 12 m / s.

[0130] The preheated sheath mixed gas is input from the outer space of the reaction chamber in the high-temperature growth tube 211 into the reaction chamber. The inlet flow rate of the sheath mixed gas is 35 m / s. In the reaction chamber, the first catalyst nanoparticle stream interacts with the sheath mixed gas. The catalyst nanoparticle stream is reduced or mildly oxidized by the sheath mixed gas. At the same time, the sheath mixed gas will quickly diffuse to the center of the first catalyst nanoparticle stream, preventing further collision and aggregation of the catalyst nanoparticles, and forming a second catalyst nanoparticle stream with a particle size of 1 nm to 6 nm and a concentration of 8×10 18 cm -3 ~9×10 20 cm -3 .

[0131] Immediately afterwards, the preheated carbon source mixed gas is introduced into the reaction chamber. The inlet flow rate of the carbon source mixed gas is 36 m / s. The flow ratio of methane and hydrogen in the carbon source mixed gas is 1:20, and the carbon source mixed gas reacts with the second catalyst nanoparticles within 6 milliseconds, thereby realizing high-crystalline SWCNTs with a controllable diameter.

[0132] The product generated in the reaction chamber is separated and collected through the collection unit 330, and the initial product is continuously collected through the transition chamber 333.

[0133] As can be seen from Table 2, the output of the initial product obtained in Example 3 is 166 g / h, the TG residue in the product is 8.6 wt%, and the G / D ratio of the product is 75.7, that is, the prepared product contains high-quality single-walled carbon nanotubes. Through the classical formula of Equation 1, the particle size distribution of the single-walled carbon nanotubes is concentrated in the range of 0.8 - 1.6 nm.

[0134] Example 4

[0135] This example is implemented with a device for micro-plasma macroscale synthesis of single-walled carbon nanotubes provided by the present invention. Ferrocene is used as the catalyst, thiophene is used as the coagulation inhibitor, argon is used as the carrier gas, hydrogen and water vapor with a volume ratio of 10:1 to 90:1 are used as the sheath mixed gas, and methane and hydrogen with a volume ratio of 1:(1 - 50) are used as the carbon source mixed gas.

[0136] A method for preparing single-walled carbon nanotubes with controllable macro-diameter, comprising the following steps:

[0137] Put ferrocene and thiophene into a conveyor 115 respectively. The molar ratio of iron and sulfur elements in ferrocene and thiophene is 30:1. Introduce an inert gas to evacuate the whole device. Preheat the carrier gas argon to 450 °C respectively with a catalyst carrier gas preheater 111 and an anti-congealing agent carrier gas preheater 112. Preheat the sheath mixed gas and the carbon source mixed gas to 1100 °C and 520 °C respectively with a sheath mixed gas preheater and a carbon source mixed gas preheater. Heat the temperature of the reaction chamber in the high-temperature growth tube 211 to 1550 °C to form a high-temperature reaction zone with a stable temperature field in the reaction chamber. At the same time, start the micro-plasma generator, and set the power of the micro-plasma generator to 120 W and the frequency to 510 MHz.

[0138] Introduce the preheated carrier gas argon into two conveyors 115 respectively. The flow rate of the carrier gas argon is 5 L / min to transport the ferrocene and thiophene in the two conveyors 115 to the evaporator 117 for evaporation, forming catalyst precursor vapor with a particle size of 1 nm to 600 nm and a volume concentration of 3×10 15 cm -3 ~9×10 18 cm -3 . The catalyst precursor vapor is ionized by the micro-plasma generator 120 to form a first catalyst nanoparticle stream with a particle size of 1 nm to 7 nm and a concentration of 2×10 17 cm -3 ~5×10 20 cm -3 . The first catalyst nanoparticle stream ejected from the micro-plasma generator 120 enters the reaction chamber in the high-temperature growth tube 211 at a flow velocity of 21 m / s.

[0139] Introduce the preheated sheath mixed gas into the reaction chamber from the outer space of the reaction chamber in the high-temperature growth tube 211. The inlet flow rate of the sheath mixed gas is 55 m / s. In the reaction chamber, the first catalyst nanoparticle stream interacts with the sheath mixed gas. The catalyst nanoparticle stream is reduced or mildly oxidized by the sheath mixed gas. At the same time, the sheath mixed gas will quickly diffuse to the center of the first catalyst nanoparticle stream, preventing further collision and aggregation of the catalyst nanoparticles, and forming a second catalyst nanoparticle stream with a particle size of 1 nm to 6 nm and a concentration of 5×10 19 cm -3 ~9×10 22 cm -3 .

[0140] Subsequently, the preheated carbon source mixed gas is introduced into the reaction chamber. The flow rate of the introduced carbon source mixed gas is 46 m / s. The flow rate ratio of methane to hydrogen in the carbon source mixed gas is 1:35. And the carbon source mixed gas is made to react with the second catalyst nanoparticles within 5 milliseconds, thereby realizing high-crystalline SWCNTs with a controllable diameter.

[0141] The products generated in the reaction chamber are separated and collected through the collection unit 330, and the initial products are continuously collected through the transition chamber 333.

[0142] As can be seen from Table 2, the output of the initial products obtained in Example 4 is 148 g / h, the TG residue in the products is 9.7 wt%, and the G / D ratio of the products is 82.5, that is, the prepared product contains high-quality single-walled carbon nanotubes. Through calculation using the classical formula of Formula 1, the particle size distribution of the single-walled carbon nanotubes is concentrated in the range of 0.8 - 1.6 nm.

[0143] Example 5

[0144] This example is implemented using the device for microplasma macroscale synthesis of single-walled carbon nanotubes provided by the present invention. In this example, ferrocene is used as the catalyst, thiophene is used as the coagulation inhibitor, argon is used as the carrier gas, hydrogen and water vapor with a volume ratio of 10:1 to 90:1 are used as the sheath mixed gas, and methane and hydrogen with a volume ratio of 1:(1 - 50) are used as the carbon source mixed gas.

[0145] A method for preparing macroscale diameter-controllable single-walled carbon nanotubes includes the following steps:

[0146] Ferrocene and thiophene are respectively placed in a conveyor 115. The molar ratio of iron to sulfur elements in ferrocene and thiophene is 60:1. An inert gas is introduced to evacuate the entire device. The carrier gas argon is preheated to 500 °C respectively by the catalyst carrier gas preheater 111 and the coagulation inhibitor carrier gas preheater 112. The sheath mixed gas and the carbon source mixed gas are preheated to 1200 °C and 610 °C respectively by the sheath mixed gas preheater and the carbon source mixed gas preheater. The temperature of the reaction chamber in the high-temperature growth tube 211 is heated to 1550 °C to form a high-temperature reaction zone with a stable temperature field in the reaction chamber. At the same time, the microplasma generator is started, and the power of the microplasma generator is set to 150 W and the frequency is set to 550 MHz.

[0147] The preheated carrier gas argon is introduced into the two conveyors 115 respectively. The flow rate of the carrier gas argon is 5 L / min to transport the ferrocene and thiophene located in the two conveyors 115 to the evaporator 117 for evaporation, forming particles with a particle size of 1 nm to 600 nm and a volume concentration of 9×10 16 cm -3 ~9×10 18 cm-3 The catalyst precursor vapor, and the catalyst precursor vapor is ionized by the microplasma generator 120 to form first catalyst nanoparticles with a particle size of 1 nm to 7 nm and a concentration of 6×10 17 cm -3 ~9×10 20 cm -3 ; The first catalyst nanoparticle stream ejected from the microplasma generator 120 enters the reaction chamber in the high-temperature growth tube 211 at a flow rate of 18 m / s.

[0148] The preheated sheath mixed gas is input from the outer space of the reaction chamber in the high-temperature growth tube 211 into the reaction chamber, and the flow rate of the sheath mixed gas is 85 m / s. In the reaction chamber, the first catalyst nanoparticle stream interacts with the sheath mixed gas, and the catalyst nanoparticle stream is reduced or mildly oxidized by the sheath mixed gas. At the same time, the sheath mixed gas quickly diffuses to the center of the first catalyst nanoparticle stream, preventing further collision and aggregation of the catalyst nanoparticles, and forming second catalyst nanoparticles with a particle size of 1 nm to 6 nm and a concentration of 9×10 20 cm -3 ~9×10 22 cm -3 .

[0149] Immediately afterwards, the preheated carbon source mixed gas is introduced into the reaction chamber, and the flow rate of the carbon source mixed gas is 78 m / s. The flow rate ratio of methane to hydrogen in the carbon source mixed gas is 1:10, and the carbon source mixed gas reacts with the second catalyst nanoparticles within 3 milliseconds, thereby realizing high-crystalline SWCNTs with a controllable diameter.

[0150] The products generated in the reaction chamber are separated and collected by the collection unit 330, and continuous collection is achieved through the transition chamber 333 to obtain the primary products.

[0151] As can be seen from Table 2, the output of the primary products obtained in Example 5 is 175 g / h, and the TG residue in the products is 6.5 wt%.

[0152] Comparative Example 1

[0153] The scheme of Comparative Example 1 is basically the same as that of Example 1, except that: the temperatures of the carrier gas, the sheath mixed gas, and the carbon source mixed gas are all at room temperature.

[0154] As can be seen from Table 2, the output of the primary products obtained in Comparative Example 1 is 33 g / h, which is significantly lower than that of Example 1. The TG residue in the products also increases to 41.1 wt%, and the G / D ratio of the products decreases to 28.3. After calculation by the classical formula of Equation 1, the particle size distribution of the single-walled carbon nanotubes is concentrated in the range of 1 - 3.2 nm, and the distribution is more dispersed compared to Example 1.

[0155] Comparative Example 2

[0156] The solution of Comparative Example 2 is basically the same as that of Example 2, except that: the flow rate of the sheath layer mixed gas is 2 m / s; the flow rate of the carbon source mixed gas is 2 m / s.

[0157] As can be seen from Table 2, the output of the initial product obtained in Comparative Example 1 is 18 g / h, which is significantly lower than that of Example 2. The TG residue in the product is 50.8 wt%, which also increases. The G / D ratio of the product decreases to 21.6. After calculation by the classical formula of Equation 1, the particle size distribution of the single-walled carbon nanotubes is concentrated in the range of 1 - 3.3 nm, and the distribution is more dispersed compared with that of Example 2.

[0158] Comparative Example 3

[0159] The solution of Comparative Example 3 is basically the same as that of Example 3, except that: the first catalyst nanoparticle stream ejected from the micro-plasma generator 120 interacts with the sheath layer mixed gas in the reaction chamber at a flow rate of 3 m / s.

[0160] As can be seen from Table 2, the output of the initial product obtained in Comparative Example 3 is 45 g / h, which is significantly lower than that of Example 3. The TG residue in the product is 18.7 wt%, which also increases. The G / D ratio of the product decreases to 33.8. After calculation by the classical formula of Equation 1, the particle size distribution of the single-walled carbon nanotubes is concentrated in the range of 1 - 3.1 nm, and the distribution is more dispersed compared with that of Example 3.

[0161] Comparative Example 4

[0162] The solution of Comparative Example 4 is basically the same as that of Example 1, except that: the reaction time between the carbon source mixed gas and the catalyst nanoparticles is 13 seconds.

[0163] As can be seen from Table 2, the output of the initial product obtained in Comparative Example 4 is 34 g / h, which is significantly lower than that of Example 4. The TG residue in the product is 21.3 wt%, which also increases. The G / D ratio of the product decreases to 45.1. After calculation by the classical formula of Equation 1, the particle size distribution of the single-walled carbon nanotubes is concentrated in the range of 1 - 3.5 nm, and the distribution is more dispersed compared with that of Example 4.

[0164] Comparative Example 5

[0165] The solution of Comparative Example 5 is basically the same as that of Example 1, except that: the sheath layer mixed gas only contains reducing gas.

[0166] As can be seen from Table 2, the initial product yield obtained in Comparative Example 5 was 108 g / h, which was significantly lower than that of Example 5. The TG residue in the product increased to 29.8 wt%, and the G / D ratio of the product decreased to 53.7. After calculation using the classical formula of Equation 1, the particle size distribution of the single-walled carbon nanotubes was concentrated in the range of 1 - 3.5 nm, and the distribution was more dispersed compared to Example 5.

[0167] The single-walled carbon nanotubes obtained in Examples 1 - 5 and Comparative Examples 1 - 5 were tested respectively. For the Raman spectroscopy, thermogravimetric characterization, scanning electron microscopy and energy-dispersive X-ray spectroscopy characterization, transmission electron microscopy characterization, and ultraviolet-visible-near-infrared absorption spectroscopy characterization methods of the single-walled carbon nanotube samples, the standards refer to GB / T 32871-2016, GB / T 24490-2009, GB / T 32869-2016, GB / T 30534-2014, and GB_T 39114-2020, and the test scheme refers to Table 1.

[0168] Table 1 Test scheme for testing single-walled carbon nanotubes in the present invention

[0169] ;

[0170] The relationship between the diameter of the single-walled carbon nanotubes and the breathing mode frequency shift is shown in Equation 1

[0171] ωRBM = A / d + B Equation 1

[0172] ωRBM is the breathing mode frequency shift, with the unit of per centimeter (cm -1 );

[0173] d is the diameter of the single-walled carbon nanotubes, with the unit of nanometer (nm);

[0174] A is a constant, with the unit of per centimeter nanometer (cm -1 nm);

[0175] B is a constant, with the unit of per centimeter (cm -1 ); For single-walled carbon nanotubes in different dielectric environments, the values of A and B are slightly different. Although the A and B parameters of different samples are not the same, the difference in the diameter of the single-walled carbon nanotubes they give is generally within the range of ±0.05 nm. For single-walled carbon nanotube samples without surface treatment, it is recommended to use A = 234 and B = 10. The chiral index of the single-walled carbon nanotubes is obtained by referring to the Kataura graph. Microscopic particle size distribution measurement equipment: Differential Mobility Analyzer (DMA), which can detect the particle diameter distribution at different positions and conditions in the detection chamber.

[0176] Table 2 Product indexes in Examples 1 - 5 and Comparative Examples 1 - 5

[0177] ;

[0178] The Raman spectra (excitation wavelength: 532 nm) of the single-walled carbon nanotubes obtained in Example 1 showed sharp graphite peaks (G band), unusually small disorder peaks (D band), and highly distinct radial breathing mode characteristic peaks RBM at amplitudes of 1570 cm -1 , 1350 cm -1 and 200 cm -1 . The ratio of the peak intensity of the G band to the peak intensity of the D band (G / D ratio) was 50.8, which is a conventional index of the graphitization degree of SWCNTs. The higher the graphitization degree means the higher the crystallinity. For SWCNTs, the G / D ratio is greater than 40. It can be said that the crystallinity of this sample is relatively high, and this relatively high value means a quite high crystallinity.

[0179] Figure 5 For the SEM characterization prepared in Example 3, it can be learned from Figure 5 that the impurity content in its product is less. Figure 6 For the Raman spectrum of the sample prepared in Example 5, it can be seen from Figure 6 that there is an obvious and sharp RBM characteristic absorption peak at about 180 cm -1 , that is, the product contains single-walled carbon nanotubes. Under the test conditions with an excitation wavelength of 532 nm, the G / D ratio of the product was calculated to be 107.2 by the classical formula of Equation 1, that is, the prepared product is high-quality single-walled carbon nanotubes.

[0180] Figure 7 The partial map of the RBM peak of the Raman spectrum of the sample prepared in Example 5 is shown. Through the statistical calculation of the breathing mode part (RBM peak) of the Raman spectrum, the diameters of the obtained SWCNTs are mainly concentrated in the ranges of 1.13 nm - 1.54 nm and 0.86 nm - 0.94 nm.

[0181] From Figure 8 and Figure 9 , it can be seen that the TEM characterization of the product prepared in Example 3 can directly show that the product contains SWCNTs with diameters of 1.30 nm and 0.94 nm, which can be mutually confirmed with the Raman characterization results of the product. This diameter distribution range is basically consistent with the diameter distribution calculated from the Raman spectrum. Further statistical analysis was carried out based on the TEM characterization results as shown in Figure 10 , and it can be seen from Figure 10It can be seen that the particle sizes of the catalyst nanoparticles in the second catalyst nanoparticle stream in Example 5 are concentrated in two peaks, with an average particle size of 1.5 nm (distributed in 1.0 - 2.0 nm) and 3.5 nm (distributed in 3.2 - 4.0 nm), and the diameters of the SWCNTs are mainly concentrated in 1.30 nm (1.13 nm - 1.54 nm) and 0.91 nm (0.86 nm - 0.94 nm).

[0182] By adopting a multi-step chemical vapor synthesis process, the present invention has successfully achieved the concentrated generation of a catalyst nanoparticle stream with a preferably sized distribution and not exceeding 6 nm under the condition of extremely high volume concentration nanoparticles (exceeding 2×10 16 cm -3 ). This innovative breakthrough effectively overcomes the problems faced by highly crystalline single-walled carbon nanotubes in terms of narrow diameter distribution and yield, opening up a new path for the development of related fields.

[0183] The present invention preheats the carrier gas, the sheath mixed gas, and the carbon source mixed gas, which not only reduces the heating load of the reactor, but also avoids the increase in the concentration of catalyst nanoparticles. At the same time, the introduction of the preheated gas also reduces the unnecessary collisions between the catalyst nanoparticles, thereby effectively suppressing the overgrowth of the catalyst nanoparticles and ensuring the uniformity and stability of the catalyst nanoparticles.

[0184] By using a preheated carrier gas, a continuously flowing microplasma, a preheated sheath mixed gas curtain, and a carbon source mixed gas curtain, and adopting a multi-step chemical vapor process to finely regulate the structure of the iron catalyst, the present invention has successfully achieved the concentrated generation of an iron nanoparticle stream with a narrow size distribution at ~1.5 nm and ~3.5 nm under the condition of high volume concentration nanoparticles (exceeding 2×10 16 cm -3 ). Further, by using these catalyst nanoparticles, single-walled carbon nanotubes with high crystallinity and narrow diameter distribution (1.30 nm and 0.91 nm) can be synthesized, and a macroscale synthesis of kilograms per day can be achieved. The present invention shows significant advantages in the macroscale preparation of diameter-controllable single-walled carbon nanotubes, and has great commercial value and broad application prospects.

[0185] It should be understood that the above embodiments are only used to illustrate the technical concept and features of the present invention, and their purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution, characterized in that: include: The catalyst and the anticoagulant are introduced into the evaporator respectively by using a carrier gas with a first temperature, wherein the first temperature is 100° C. to 500° C., and the catalyst and the anticoagulant are mixed and evaporated in the evaporator to form catalyst precursor vapor, wherein the volume concentration of the catalyst precursor vapor is 3×10 15 cm -3 ~9×10 18 cm -3 ; The catalyst precursor vapor is introduced into a microplasma reactor to be ionized to form a first catalyst nanoparticle flow, and the first catalyst nanoparticle flow is transported into a reaction chamber having a second temperature at a first flow rate, wherein the concentration of the catalyst nanoparticles in the first catalyst nanoparticle flow is 2×10 16 cm -3 ~9×10 20 cm -3 , the first flow velocity is 5 m / s to 12 m / s, and the second temperature is 800° C. to 1800° C.; The sheath mixed gas is first preheated to a third temperature, and then the sheath mixed gas is input into the reaction chamber, and the sheath mixed gas surrounds the first catalyst nanoparticle flow and maintains a second flow rate, the third temperature is 300°C to 1200°C, the second flow rate is 3 m / s to 90 m / s, the catalyst nanoparticles in the first catalyst nanoparticle flow are reduced or oxidized by the sheath mixed gas, the sheath mixed gas quickly diffuses to the central area of ​​the first catalyst nanoparticle flow, and prevents collision and aggregation between catalyst nanoparticles, thereby obtaining a second catalyst nanoparticle flow, and the concentration of catalyst nanoparticles in the second catalyst nanoparticle flow is 2×10 16 cm -3 ~9×10 22 cm -3 The particle size distribution range of the catalyst nanoparticles contained in the second catalyst nanoparticle flow is smaller than the particle size distribution range of the catalyst nanoparticles contained in the first catalyst nanoparticle flow, the particle size of the catalyst nanoparticles contained in the second catalyst nanoparticle flow has a bimodal size distribution, and the sheath mixed gas includes a reducing gas and water vapor or oxygen.

2. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 1, characterized in that: The flow rate of the carrier gas is 0.05 L / min to 15 L / min.

3. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 1, characterized in that: The carrier gas includes an inert gas.

4. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 1, characterized in that: The particle size of the catalyst precursor particles contained in the catalyst precursor vapor is 1 nm to 600 nm.

5. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 1, characterized in that: The particle size of the catalyst nanoparticles in the first catalyst nanoparticle flow is 1 nm to 12 nm.

6. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 5, characterized in that: The particle sizes of the catalyst nanoparticles in the second catalyst nanoparticle flow are mainly distributed in the range of 1 nm to 2 nm and 3.2 nm to 4 nm.

7. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 1, characterized in that: The catalyst includes organic matter containing iron, and the anticoagulant includes a compound or a mixture containing sulfur.

8. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 7, characterized in that: The molar ratio of the iron element in the catalyst to the sulfur element in the anticoagulant is 2:1 to 60:

1.

9. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 7, characterized in that: The catalyst includes ferrocene.

10. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 7, characterized in that: The anticoagulant includes at least one of thiophene, dimethyl sulfoxide, sulfur powder, hydrogen sulfide, and sulfur dioxide, or a combination of two or more thereof.

11. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 7, characterized in that: The reducing gas in the sheath mixed gas includes at least one of hydrogen, carbon monoxide and ammonia.

12. The method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to claim 7, characterized in that: The volume ratio of the reducing gas to the water vapor or the oxygen is 10:1 to 90:

1.

13. A method for synthesizing large quantities of single-walled carbon nanotubes with controllable diameters, characterized in that: include: Forming a catalyst nanoparticle stream by using the method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution as described in any one of claims 1 to 12; A carbon source mixed gas having a fourth temperature is introduced into the reaction chamber, and the carbon source mixed gas is maintained at a third flow rate. Under the second temperature condition, the catalyst nanoparticles are 1 nm to 6 nm in diameter and 2×10 16 cm -3 ~9×10 22 cm -3 The catalyst nanoparticle flow and the carbon source mixed gas are mixed and reacted within 1 millisecond to 10 milliseconds to obtain single-walled carbon nanotubes with controllable diameters. The fourth temperature is 230°C to 650°C.

14. The method for macro-synthesis of single-walled carbon nanotubes with controllable diameter according to claim 13, characterized in that: The method for macro-synthesizing single-walled carbon nanotubes with controllable diameter specifically comprises: firstly preheating the carbon source mixed gas to a fourth temperature, and then inputting the carbon source mixed gas into the reaction chamber.

15. The method for macro-synthesis of single-walled carbon nanotubes with controllable diameter according to claim 13, characterized in that: The third flow velocity is 3 m / s~90 m / s.

16. The method for macro-synthesis of single-walled carbon nanotubes with controllable diameter according to claim 13, characterized in that: The carbon source mixed gas includes a carbon source gas and a reducing gas.

17. The method for macro-synthesis of single-walled carbon nanotubes with controllable diameter according to claim 16, characterized in that: The volume ratio of the carbon source gas to the reducing gas is 1:(1-50).

18. The method for macro-synthesis of single-walled carbon nanotubes with controllable diameter according to claim 16, characterized in that: The flow ratio of the carbon source gas contained in the carbon source mixed gas to the reducing gas contained in the sheath mixed gas is 1:(2-35).

19. The method for macro-synthesis of single-walled carbon nanotubes with controllable diameter according to claim 16, characterized in that: The carbon source gas includes at least one of natural gas, methane, ethane, propane, butane, pentane, hexane, ethylene, propylene, ethanol, anthracene or anthracene oil vapor.

20. The method for macro-synthesis of single-walled carbon nanotubes with controllable diameter according to claim 16, characterized in that: The reducing gas contained in the carbon source mixed gas includes at least one of hydrogen, carbon monoxide and ammonia.

21. A single-walled carbon nanotube, characterized in that: The single-walled carbon nanotubes are prepared by the method for macro-synthesis of controllable diameter single-walled carbon nanotubes as described in any one of claims 13-20, the G / D ratio of the single-walled carbon nanotubes exceeds 50, and the diameters of the single-walled carbon nanotubes are mainly concentrated in the range of 1.13nm~1.54nm and 0.86nm~0.94nm.

22. An apparatus for implementing the method for preparing catalyst nanoparticles with high volume concentration and narrow diameter distribution according to any one of claims 1 to 12, characterized in that: include: A catalyst supply mechanism, an anticoagulant supply mechanism, an evaporator, a microplasma generator, a sheath mixed gas supply mechanism and a reaction mechanism, wherein the catalyst supply mechanism and the anticoagulant supply mechanism are connected to the evaporator respectively, the evaporator is connected to the microplasma generator, the reaction mechanism comprises a reaction chamber, a heating mechanism, a catalyst nanoparticle flow injection port and a sheath mixed gas air curtain injection port communicated with the reaction chamber, the sheath mixed gas air curtain injection port is arranged around the catalyst nanoparticle flow injection port, the microplasma generator is connected to the catalyst nanoparticle flow injection port, the sheath mixed gas supply mechanism is connected to the sheath mixed gas air curtain injection port, and the heating mechanism is used to maintain the ambient temperature in the reaction chamber at a second temperature; The catalyst supply mechanism is used to preheat the catalyst and introduce the catalyst into the evaporator, the anticoagulant supply mechanism is used to preheat the catalyst and introduce the anticoagulant into the evaporator, the evaporator is used to evaporate and mix the introduced catalyst and anticoagulant to form a catalyst precursor vapor, the microplasma generator is used to decompose the catalyst precursor vapor to form a first catalyst nanoparticle flow, and introduce the first catalyst nanoparticle flow into the reaction chamber, the sheath mixed gas supply mechanism is used to preheat the sheath mixed gas and introduce the sheath mixed gas into the reaction chamber, the sheath mixed gas is distributed around the catalyst nanoparticle flow, and the sheath mixed gas can reduce or oxidize the catalyst nanoparticle flow, and the sheath mixed gas can quickly diffuse to the central area of ​​the catalyst nanoparticle flow and prevent collision and aggregation between catalyst nanoparticles.

23. The device according to claim 22, characterized in that: The catalyst supply mechanism includes a catalyst carrier gas preheater and a catalyst conveyor, the catalyst carrier gas preheater and the catalyst conveyor are connected in sequence, and the catalyst conveyor is connected to the evaporator. The anticoagulant supply mechanism includes an anticoagulant carrier gas preheater and an anticoagulant conveyor, the anticoagulant carrier gas preheater and the anticoagulant conveyor are connected in sequence, and the anticoagulant conveyor is connected to the evaporator.

24. A device for implementing the method for macro-synthesis of single-walled carbon nanotubes with controllable diameter as claimed in any one of claims 13 to 20, characterized in that: include: A catalyst nanoparticle preparation unit comprises a catalyst supply mechanism, an anticoagulant supply mechanism, an evaporator, and a microplasma generator, wherein the catalyst supply mechanism and the anticoagulant supply mechanism are respectively connected to the evaporator, and the evaporator is connected to the microplasma generator. The catalyst supply mechanism is used to preheat the catalyst and introduce the catalyst into the evaporator, the anticoagulant supply mechanism is used to preheat the catalyst and introduce the anticoagulant into the evaporator, the evaporator is used to evaporate and mix the introduced catalyst and anticoagulant to form catalyst precursor vapor, and the microplasma generator is used to decompose the catalyst precursor vapor to form a first catalyst nanoparticle flow, and introduce the first catalyst nanoparticle flow into a reaction chamber; The reaction unit comprises a carbon source mixed gas supply mechanism, a sheath mixed gas supply mechanism and a reaction mechanism, wherein the reaction mechanism comprises a reaction chamber, a heating mechanism and a catalyst nanoparticle flow injection port, a sheath mixed gas air curtain injection port and a carbon source mixed gas injection port which are connected to the reaction chamber, wherein the sheath mixed gas air curtain injection port is arranged around the catalyst nanoparticle flow injection port, the micro plasma generator is connected to the catalyst nanoparticle flow injection port, the sheath mixed gas supply mechanism is connected to the sheath mixed gas air curtain injection port, the carbon source mixed gas supply mechanism is connected to the carbon source mixed gas injection port, and the heating mechanism The structure is used to maintain the ambient temperature in the reaction chamber at a second temperature, the sheath mixed gas supply mechanism is used to preheat the sheath mixed gas and introduce the sheath mixed gas into the reaction chamber, the carbon source mixed gas supply mechanism is used to preheat the carbon source mixed gas and introduce the carbon source mixed gas into the reaction chamber, the sheath mixed gas is distributed around the catalyst nanoparticle flow, and the sheath mixed gas can reduce or oxidize the catalyst nanoparticle flow, and the sheath mixed gas can quickly diffuse to the central area of ​​the catalyst nanoparticle flow and prevent collision and aggregation between catalyst nanoparticles.

25. The device according to claim 24, characterized in that: The catalyst supply mechanism includes a catalyst carrier gas preheater and a catalyst conveyor, the catalyst carrier gas preheater and the catalyst conveyor are connected in sequence, and the catalyst conveyor is connected to the evaporator. The anticoagulant supply mechanism includes an anticoagulant carrier gas preheater and an anticoagulant conveyor, the anticoagulant carrier gas preheater and the anticoagulant conveyor are connected in sequence, and the anticoagulant conveyor is connected to the evaporator.

26. The device according to claim 24, characterized in that: The device for macro-synthesis of single-walled carbon nanotubes with controllable diameter also includes: a product collection unit, which is connected to the reaction chamber and is used for gas-solid separation of the generated single-walled carbon nanotubes and can realize continuous collection.

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