Peak-valley confined catalyst structure and preparation method of highly oriented spinnable carbon nanotube array

Abstract

This invention relates to a peak-valley confined catalyst structure and a method for preparing a highly oriented spinnable carbon nanotube array. The peak-valley confined catalyst structure comprises a silicon substrate covered with a silica layer, a lower alumina layer, a metal catalyst layer, and an upper alumina layer, stacked sequentially. The contact surface between the lower alumina layer and the metal catalyst layer has a continuous peak-valley structure. The upper alumina layer and the peak-valley morphology work together to restrict the movement and aggregation of the catalyst at high temperatures. Subsequently, carbon nanotube arrays are grown based on the peak-valley confined catalyst structure using a water-assisted chemical vapor deposition method. During this process, the introduction of water vapor effectively removes amorphous carbon from the substrate and the surface of the carbon nanotubes, ensuring high cleanliness of the catalyst and the carbon nanotube array. The high-temperature hydrogen annealing, combined with the peak-valley confined catalyst structure, ensures uniform catalyst particle size and distribution, resulting in a highly oriented spinnable carbon nanotube array.

Description

Technical Field

[0001] This invention belongs to the field of carbon nanotube preparation technology, specifically relating to a method for preparing a peak-valley confined catalyst structure and a highly oriented spinnable carbon nanotube array. Background Technology

[0002] Carbon nanotubes are hollow tubular carbon nanomaterials with ultra-high aspect ratios, possessing excellent electrical conductivity, ultra-high tensile strength, and Young's modulus, thus earning them the title of "ultimate fiber material." As macroscopic entities composed of aggregated carbon nanotubes, carbon nanotube arrays exhibit a forest-like morphology. The carbon nanotubes within the array are uniformly oriented and their structure is tunable, allowing carbon nanotube fibers prepared from carbon nanotube arrays to better utilize the inherent properties of carbon nanotubes. The preparation of spinnable carbon nanotube arrays is the core of carbon nanotube array spinning. By drawing spinnable carbon nanotube arrays into fibers and processing them through twisting and other techniques, high-performance carbon nanotube fibers can be obtained, showing broad application prospects in flexible batteries, composite materials, and artificial muscles.

[0003] This technology marks the first time carbon nanotube fibers have been extracted from a 100 μm high carbon nanotube array, and subsequently, the theory of superaligned arrays was proposed. Following this, a 1.5 mm high spinnable carbon nanotube array was prepared using an anhydrous-assisted method. Furthermore, the existing technology utilizes hydrogen assistance to improve the orientation of the carbon nanotube array, resulting in carbon nanotube fibers with superior properties.

[0004] However, due to the narrow growth window of spinnable carbon nanotube arrays, there are extremely high design requirements for catalysts. Current growth techniques are prone to problems such as uneven catalyst particle size and distribution, as well as catalyst particle deactivation during the growth of carbon nanotube arrays, which results in the carbon nanotube arrays not being spinnable. Summary of the Invention

[0005] Based on the aforementioned shortcomings and deficiencies in the prior art, one of the objectives of this invention is to at least solve one or more of the aforementioned problems in the prior art. In other words, one of the objectives of this invention is to provide a method for preparing a peak-valley confined catalyst structure and a highly oriented spinnable carbon nanotube array that meets one or more of the aforementioned requirements.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A peak-valley confined catalyst structure includes a silicon substrate covered with a silicon dioxide layer, a lower alumina layer, a metal catalyst layer, and an upper alumina layer stacked sequentially, wherein the contact surface between the lower alumina layer and the metal catalyst layer has a continuous peak-valley structure.

[0007] As a preferred embodiment, the processing of the peak-valley confined catalyst structure includes: (1) A lower layer of aluminum oxide is sputtered on a clean silicon substrate covered with a silicon dioxide layer by magnetron sputtering, and the surface of the lower layer of aluminum oxide is etched by argon plasma to form a continuous peak-valley structure. (2) Sputter a metal catalyst layer onto the surface of the lower alumina layer; (3) Sputter an upper layer of alumina onto the surface of the metal catalyst layer to obtain a peak-valley confined catalyst structure.

[0008] As a preferred embodiment, the thickness of the silicon dioxide layer is 20-500 nm, the sputtering thickness of the lower alumina layer is 500-1000 nm, the sputtering thickness of the metal catalyst layer is 2-3 nm, and the sputtering thickness of the upper alumina layer is 0.5-20 nm.

[0009] As a preferred embodiment, the metal catalyst layer is made of iron, copper, cobalt, or nickel.

[0010] As a preferred embodiment, the argon plasma etching power is 5-9 W and the etching time is 1-3 min.

[0011] This invention also provides a method for preparing highly oriented spinnable carbon nanotube arrays, comprising the following steps: S1. Place the peak-valley confined catalyst structure as described in any of the above schemes into a tube furnace and heat it under argon protection. S2. The tube furnace is heated to the growth temperature under argon protection, and bubbling water vapor, hydrogen and ethylene are supplied in sequence to grow carbon nanotube arrays. S3. After growth is complete, turn off other gases, increase the argon flow rate to terminate growth, and complete the cooling of the tube furnace under argon protection. After the temperature drops to room temperature, turn off the argon gas and remove the highly oriented spinnable carbon nanotube array.

[0012] As a preferred embodiment, the growth temperature is 600-900℃.

[0013] As a preferred embodiment, in step S2, argon gas is continuously introduced at a rate of 370-700 sccm. Bubbling water vapor is introduced at a rate of 20-100 sccm 10-20 minutes before reaching the growth temperature. Hydrogen gas is then introduced at a rate of 50-100 sccm after reaching the growth temperature. After reaching the growth temperature, ethylene gas is introduced at a preset interval at a time. The atmosphere inside the tubular furnace is maintained for 10-20 minutes after the introduction of ethylene. Throughout the process, the total gas flow rate inside the tubular furnace remains constant and is maintained at 370-700 sccm.

[0014] As a preferred option, the preset duration is 3-8 minutes.

[0015] As a preferred embodiment, in step S3, the argon flow rate is increased to 800-1200 sccm for a duration of 3-5 min.

[0016] Compared with the prior art, the beneficial effects of this invention are: (1) The present invention replaces the flat catalyst structure with a peak-valley confined catalyst structure. The lower alumina completely covers the substrate surface. While preparing for the subsequent catalyst process, the double buffer layer composed of the lower alumina and the silica layer greatly reduces the possibility of poisoning and deactivation of the metal catalyst and silicon at high temperature. Argon plasma treatment shapes the continuous peak-valley morphology on the surface of the lower alumina, which is conducive to the uniform distribution and dispersion of the catalyst and reduces the negative impact of Ostwald ripening on the catalyst. The sputtered low-thickness upper alumina is uniformly distributed on the top layer. Its combined action with the bottom peak-valley morphology can not only restrict the movement and aggregation of the catalyst at high temperature, but also constrain the growth direction of carbon nanotubes, making the grown carbon nanotube array more uniformly distributed and more oriented. (2) Before reaching the growth temperature, the present invention first introduces bubbling water vapor as an oxidant to remove amorphous carbon, ensuring the cleanliness of the substrate surface, which is beneficial to improving the spinnability of carbon nanotube arrays; by controlling the hydrogen annealing time and the interlayer catalyst structure, catalyst particles with uniform size and distribution can be obtained after annealing, and carbon nanotube arrays with higher orientation and better spinnability can be grown. (3) The carbon nanotube array prepared by the present invention has high spinnability stability and good repeatability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process for preparing highly oriented spinnable carbon nanotube arrays according to the present invention; Figure 2 This is a spinning photograph of the spinnable carbon nanotube array prepared on a silicon wafer substrate according to the present invention. Figure 3 These are spinning images of highly oriented spinnable carbon nanotube arrays prepared on silicon wafer substrates according to the present invention, as well as scanning electron microscope images of the fibers. Figure 4 This is a scanning electron microscope image of the highly oriented spinnable carbon nanotube array obtained in Example 1; Figure 5 This is a scanning electron microscope image of the carbon nanotube array obtained in Example 2; Figure 6 This is a scanning electron microscope image of the carbon nanotube array obtained in Comparative Example 1. Figure 7 This is a scanning electron microscope image of the carbon nanotube array obtained in Comparative Example 2; Figure 8This is a scanning electron microscope image of the carbon nanotube array obtained in Comparative Example 3. Figure 9 This is a scanning electron microscope image of the carbon nanotube array obtained in Comparative Example 4. Figure 10 These are atomic force microscopy images of the substrate surfaces after sputtering the lower layer of alumina in Example 1 and Comparative Example 1; Figure 11 These are atomic force microscopy images of the substrate surfaces of Example 1 and Comparative Example 2 after argon plasma etching; Figure 12 These are atomic force microscopy images of the peak-valley confined catalyst morphology before and after annealing for 5 min in Example 1. Figure 13 This is an atomic force microscope image of the peak-valley confined catalyst morphology of Comparative Example 4 after annealing for 5 min. Figure 14 This is a mechanism diagram of the peak-valley confined catalyst of the present invention. Detailed Implementation

[0018] The following provides a detailed description of the peak-valley confined catalyst structure and the preparation method of the highly oriented spinnable carbon nanotube array of the present invention.

[0019] This invention first involves sputtering a thick lower layer of alumina onto the surface of a silicon wafer containing a silicon dioxide layer using magnetron sputtering. Then, the surface of the lower alumina layer is etched using argon plasma, and an iron catalyst is sputtered onto the etched surface. Finally, an upper layer of alumina is sputtered based on the previous step. Under the physical etching effect of argon plasma, the lower alumina layer forms a continuous peak-valley morphology, and the sputtered iron catalyst falls uniformly into the peaks and valleys, ensuring uniform distribution and dispersion of the catalyst on the substrate surface. The combined effect of the upper alumina layer and the peak-valley morphology restricts the movement and aggregation of the catalyst at high temperatures. Next, carbon nanotube arrays are grown: the prepared substrate containing the sandwiched catalyst structure is placed in a tube furnace, and chemical vapor deposition is performed using a water-assisted method. During this process, the introduction of water vapor effectively removes amorphous carbon from the substrate and the surface of the carbon nanotubes, ensuring high cleanliness of the catalyst and the carbon nanotube array; while high-temperature hydrogen annealing and the peak-valley confined catalyst structure work together to ensure uniform catalyst particle size and distribution. The spinnable carbon nanotube arrays prepared by this method have high orientation, uniform diameter and distribution of carbon nanotubes, and are characterized by high stability and good repeatability.

[0020] like Figure 1 As shown, the preparation method of the highly oriented spinnable carbon nanotube array of the present invention is divided into two parts: processing of peak-valley confined catalyst structure and growth of carbon nanotube array. The processing of peak-valley confined catalyst structures includes: Ⅰ. Sputter a thick layer of alumina onto a clean substrate surface covered with a silica layer; The thickness of the silicon dioxide layer is 20-500 nm, and the specific thickness can be determined according to the actual application requirements. The thickness of the lower alumina layer is in the range of 500-1000 nm, and the specific thickness can be determined according to the actual application requirements.

[0021] II. The surface of the lower layer of alumina was etched with argon plasma to obtain a peak-valley structure morphology; Specifically, the argon plasma etching time ranges from 1 to 3 minutes, and the etching power ranges from 5 to 9 W. The specific power and time can be determined according to the actual application.

[0022] III. Sputter a metal catalyst (such as an iron catalyst layer) onto the substrate surface obtained in step II. Specifically, the sputtering thickness of the metal catalyst ranges from 2 to 3 nm, and the required thickness can be determined according to the actual application requirements. The metal catalyst can be iron, copper, cobalt, or nickel, and the specific choice can be made according to the actual application requirements.

[0023] IV. Sputter an upper layer of alumina onto the substrate surface obtained in step III, forming the final peak-valley confined catalyst structure on the substrate surface; The thickness of the upper alumina layer ranges from 0.5 to 20 nm, and the specific thickness can be determined according to the actual application requirements.

[0024] The peak-valley confined catalyst structure prepared above includes a silicon substrate covered with a silica layer, a lower alumina layer, a metal catalyst layer, and an upper alumina layer stacked sequentially. The contact surface between the lower alumina layer and the metal catalyst layer is a continuous peak-valley structure. That is, the peak-valley confined catalyst structure includes a substrate with a periodic undulating topology, a catalyst active layer located in the valley region of the topology, and a capping layer covering part of the undulating topology to fix and selectively expose the catalyst active layer.

[0025] Furthermore, the growth process of the carbon nanotube array includes: V. Place the substrate with a peak-valley confined catalyst structure into a tube furnace; VI. The tube furnace is heated to the growth temperature under argon protection, and bubbling water vapor, hydrogen and ethylene are supplied in sequence to grow carbon nanotube arrays. The specific growth process is as follows: From the start of heating, continuously introduce argon gas at a pressure of 370-700 sccm; 10-20 minutes before reaching the growth temperature, introduce 20-100 sccm of bubbling water vapor to remove amorphous carbon from the substrate surface and prevent catalyst poisoning and deactivation. Once the growth temperature is reached, 50-100 sccm of hydrogen gas is introduced to reduce the oxidized metal catalyst. At the same time, the catalyst film is cracked at high temperature, causing it to aggregate and fuse to form catalyst particles. After reaching the growth temperature, 100-200 sccm of ethylene is introduced at intervals of 3-8 minutes, and the atmosphere inside the tubular furnace is maintained for 10-20 minutes to grow carbon nanotube arrays. Throughout the process, the total gas flow rate inside the tubular furnace remains constant and is maintained at 370-700 sccm; The aforementioned growth temperature range is 600-900 ℃; The specific flow rate, temperature, and time mentioned above can be determined according to actual application requirements; VII. After growth is complete, interrupt other gases and introduce a high flow rate of argon to terminate the experiment; The argon flow rate is increased to 800-1200 sccm for 3-5 minutes. The specific flow rate and time can be determined according to the actual application requirements. VIII. The tube furnace cooling process is completed under argon protection. After the temperature drops to room temperature, the argon gas is turned off and the sample is taken out to obtain a highly oriented spinnable carbon nanotube array.

[0026] The following specific examples and comparative examples further explain the peak-valley confined catalyst structure and the preparation method of highly oriented spinnable carbon nanotube arrays of the present invention.

[0027] Example 1: The method for preparing the spinnable carbon nanotube array in this embodiment includes the following steps: The first step is to sputter a 1000nm lower layer of aluminum oxide onto a clean silicon wafer surface containing a 200 nm silicon dioxide layer using magnetron sputtering. The second step involves etching the substrate surface with argon plasma for 1 minute, based on the first step, at a etching power of 7 W. The third step involves applying a 2.5 nm iron catalyst layer by magnetron sputtering, building upon the second step. The fourth step involves applying a 2.8 nm layer of alumina using magnetron sputtering, based on the third step, to obtain a substrate sample containing a peak-valley confined catalyst structure.

[0028] The fifth step involves placing the substrate sample containing the peak-valley confined catalyst structure into a 1.85-inch high-temperature tube furnace and heating it to 550°C at 510 sccm in an argon atmosphere. Step 6: Introduce bubbling water vapor (argon bubbling, 50 sccm) and keep the total flow rate constant at 510 sccm, then continue heating to 750℃; subsequently, introduce 80 sccm of hydrogen for 5 min and keep the total flow rate constant at 510 sccm; finally, introduce 180 sccm of ethylene and keep the total flow rate constant at 510 sccm to grow the carbon nanotube array for 15 min. Step 7: Stop the reaction by turning off ethylene, hydrogen and bubbling water vapor, and maintain argon gas at 1000 sccm for 5 min; Step 8: Maintain an argon flow rate of 510 sccm for the cooling process, and remove the sample after it has cooled to room temperature.

[0029] Example 2: The method for preparing the spinnable carbon nanotube array in this embodiment differs from that in Example 1 in that: In the third step, the iron catalyst layer thickness is sputtered to 2.0 nm, and in the fourth step, the upper alumina layer thickness is sputtered to 0.5 nm. Other steps can be found in Example 1.

[0030] Comparative Example 1: The preparation method of the carbon nanotube array in this comparative example differs from that in Example 1 in that: In the first step, the thickness of the lower alumina layer is sputtered to 166 nm; in the third step, the thickness of the iron catalyst layer is sputtered to 2.0 nm; and in the fourth step, the thickness of the upper alumina layer is sputtered to 0.5 nm. Other steps can be found in Example 1.

[0031] Comparative Example 2: The preparation method of the carbon nanotube array in this comparative example differs from that in Example 1 in that: The second step involves argon plasma etching of the substrate surface for 60 min; the third step involves sputtering the iron catalyst layer to a thickness of 2.0 nm; and the fourth step involves sputtering the upper alumina layer to a thickness of 0.5 nm. Other steps can be found in Example 1.

[0032] Comparative Example 3: The preparation method of the carbon nanotube array in this comparative example differs from that in Example 1 in that: The third step involves sputtering the iron catalyst layer to a thickness of 2.0 nm, and the fourth step is omitted, meaning that the upper alumina layer is absent. Other steps can be found in Example 1.

[0033] Comparative Example 4: The preparation method of the carbon nanotube array in this comparative example differs from that in Example 1 in that: The third step involves sputtering the iron catalyst layer to a thickness of 5.0 nm. Other steps can be found in Example 1.

[0034] like Figure 2 The image shown is a spinning image of the carbon nanotube array prepared under the conditions described in Example 1 above. Figure 3 The image shown is a scanning electron microscope (SEM) image of the carbon nanotube fibers prepared from the sample in Example 1. Figure 4 This is a scanning electron microscope image of the highly oriented carbon nanotube array prepared in Example 1. Figure 12 These are scanning electron microscope (SEM) images of the peak-valley confined catalyst morphology of Example 1 before and after annealing, as shown in Table 1. Figure 2 , Figure 3 , Figure 4 as well as Figure 12 Data shows that, under the conditions of Example 1, the peak-valley confined catalyst particles are uniform in size and distribution after annealing, and the prepared carbon nanotube array has the best orientation. At the same time, carbon nanotube filaments of more than one meter can be continuously drawn from the array, which has high spinnability.

[0035] Figure 5 Here are scanning electron microscope images of the carbon nanotube array from Example 2, as shown in Table 1 and... Figure 5 It can be observed that, compared with Example 1, the orientation and spinnability of the sample of Example 2, obtained by changing the thickness of the iron catalyst layer and the thickness of the upper alumina layer, are reduced.

[0036] Figure 10 These are atomic force microscopy (AFM) images of the substrate surfaces of Example 1 and Comparative Example 1, showing the surface morphology of the substrates after sputtering a 1000 nm thick and a 166 nm thick lower alumina layer, respectively. It can be clearly seen that the lower alumina layer in Example 1 is completely and densely distributed on the substrate, while the lower alumina layer in Comparative Example 1 is more dispersed in a serrated pattern and does not completely cover the substrate. Since alumina sputtering is a point-to-surface process, to reduce the total surface energy of the system, alumina tends to aggregate in an island-like form. At lower sputtering times or thicknesses, alumina cannot completely cover the entire substrate surface, which affects subsequent processes and the growth of the carbon nanotube array. However, when the sputtering time or thickness is sufficiently high, the alumina is uniformly and densely distributed on the substrate, which is important for subsequent processing and the uniform growth of the carbon nanotube array.

[0037] Figure 6 The images shown are scanning electron microscope (SEM) images of the carbon nanotube arrays prepared in Comparative Example 1. (See Table 1 for details.) Figure 6 and Figure 10 It can be seen that the lower thickness of the alumina layer directly affects the orientation and spinnability of the array. In Comparative Example 1, the carbon nanotube array has a disordered orientation and does not have spinnability.

[0038] Figure 11 Atomic force microscopy (AFM) images of the substrate surfaces of Example 1 and Comparative Example 2 after argon plasma etching are shown. When argon plasma etching lasts for 1 minute, a uniform and dense alumina peak-shaped morphology forms on the substrate surface of Example 1. However, when argon plasma etching lasts for 1 hour, the alumina peaks on the substrate surface of Comparative Example 2 are dispersed and of varying heights. This is a change in alumina morphology caused by excessively long etching times. It can be understood that the alumina morphology of Example 1 after 1 minute of argon plasma treatment is more conducive to the catalyst existing within it in a uniform size and distribution. This is also an important peak-valley morphology formed by our peak-valley confined catalyst design; etching times that are too short or too long will prevent the formation of peak-valley morphologies.

[0039] Figure 7 The image shows a scanning electron microscope (SEM) image of the carbon nanotube array in Comparative Example 2, as shown in Table 1. Figure 7 and Figure 11 It can be seen that excessive etching by plasma affects the substrate morphology and also has a negative impact on the orientation degree and spinnability of the array. The orientation degree of the carbon nanotube array in Comparative Example 2 is generally poor and it does not have spinnability.

[0040] Figure 8 This is a scanning electron microscope (SEM) image of the carbon nanotube array in Comparative Example 3. Compared to Example 2, the process in Comparative Example 3 does not include an upper layer of alumina. (See Table 1 for details.) Figure 5 and Figure 8 Comparing Example 2 and Comparative Example 3, it can be seen that the presence of the upper alumina layer effectively improves the orientation degree of the carbon nanotube array. Since the orientation degree of the carbon nanotube array is strongly correlated with its spinnability, the upper alumina layer is of great significance in improving the spinnability of the carbon nanotube array.

[0041] Figure 9 This is a scanning electron microscope (SEM) image of the carbon nanotube array in Comparative Example 4. Compared to Example 1, the iron catalyst layer thickness in Comparative Example 4 is 5 nm. Figure 12 , Figure 13 Scanning electron microscope (SEM) images of the peak-valley confined catalysts from Comparative Example 1 and Comparative Example 4 after annealing for 5 min show that the excessively thick catalyst layer in Comparative Example 4 resulted in excessively large, inconsistent, and unevenly distributed catalyst particles after annealing. Figure 9 As shown in Table 1, the catalyst thickness directly affects the orientation degree and spinnability of Comparative Example 4. Therefore, for the growth of spinnable carbon nanotube arrays, the catalyst thickness needs to be strictly controlled within a narrow range.

[0042] Evaluation Method: The orientation degree of carbon nanotube arrays was quantitatively evaluated using the Hearman Orientation Factor (HOF). The HOF was calculated by importing the side scanning electron microscope images of the carbon nanotube arrays into ImageJ software for processing and data extraction. The HOF characterizes the degree of orderliness of the carbon nanotube array, ranging from -0.5 to 1. When the HOF value is -0.5 or 1, it indicates that the carbon nanotube array is completely vertically or completely horizontally aligned; while when the HOF value is close to 0, the carbon nanotubes are completely randomly arranged.

[0043] Table 1 shows the spinnability data of the carbon nanotube arrays prepared in each embodiment and comparative example. .

[0044] In addition, such as Figure 14 The diagram illustrates the state changes of the peak-valley confined catalyst of this invention during high-temperature annealing. During annealing, the iron catalyst layer first undergoes decomposition to form iron nanoparticles. To reduce the total energy of the system, the iron nanoparticles tend to fuse together, existing in the form of large iron particles. The peak-valley buffer layer morphology and the upper alumina layer restrict the fusion and aggregation of iron nanoparticles during annealing. After the iron nanoparticles aggregate into iron catalyst particles of a certain size, their further movement and aggregation are restricted. Therefore, after the annealing process, the size and distribution of the iron catalyst particles are relatively uniform. The carbon nanotube array grown with this catalyst has good uniformity, high orientation, and spinnable properties.

[0045] Given that there are numerous embodiments of the present invention, and the process parameters involved can be selected within a limited range according to actual needs, and the experimental data for each embodiment are extensive and numerous, it is not suitable to list and describe them one by one here. However, the content to be verified and the final conclusions obtained in each embodiment are similar. Therefore, the verification content of each embodiment will not be described one by one here.

[0046] The above description is merely a detailed explanation of preferred embodiments and principles of the present invention. For those skilled in the art, there may be changes in specific implementation methods based on the ideas provided by the present invention, and these changes should also be considered within the scope of protection of the present invention.

Claims

1. A peak-valley confined catalyst structure, characterized in that, It includes a silicon substrate covered with a silicon dioxide layer, a lower alumina layer, a metal catalyst layer, and an upper alumina layer stacked in sequence, wherein the contact surface between the lower alumina layer and the metal catalyst layer has a continuous peak-valley structure.

2. The peak-valley confined catalyst structure according to claim 1, characterized in that, The processing of the peak-valley confined catalyst structure includes: (1) A lower layer of aluminum oxide is sputtered on a clean silicon substrate covered with a silicon dioxide layer by magnetron sputtering, and the surface of the lower layer of aluminum oxide is etched by argon plasma to form a continuous peak-valley structure. (2) Sputter a metal catalyst layer onto the surface of the lower alumina layer; (3) Sputter an upper layer of alumina onto the surface of the metal catalyst layer to obtain a peak-valley confined catalyst structure.

3. The peak-valley confined catalyst structure according to claim 2, characterized in that, The thickness of the silicon dioxide layer is 20-500 nm, the sputtering thickness of the lower alumina layer is 500-1000 nm, the sputtering thickness of the metal catalyst layer is 2-3 nm, and the sputtering thickness of the upper alumina layer is 0.5-20 nm.

4. The peak-valley confined catalyst structure according to claim 2, characterized in that, The metal catalyst layer is made of iron, copper, cobalt, or nickel.

5. The peak-valley confined catalyst structure according to claim 2, characterized in that, The argon plasma etching power is 5-9W, and the etching time is 1-3min.

6. A method for preparing a highly oriented spinnable carbon nanotube array, characterized in that, Includes the following steps: S1. Place the peak-valley confined catalyst structure as described in any one of claims 1-5 into a tube furnace; S2. The tube furnace is heated to the growth temperature under argon protection, and bubbling water vapor, hydrogen and ethylene are supplied in sequence to grow carbon nanotube arrays. S3. After growth is complete, turn off other gases, increase the argon flow rate to terminate growth, and complete the cooling of the tube furnace under argon protection. After the temperature drops to room temperature, turn off the argon gas and remove the highly oriented spinnable carbon nanotube array.

7. The preparation method according to claim 6, characterized in that, The growth temperature is 600-900℃.

8. The preparation method according to claim 6, characterized in that, In step S2, argon gas is continuously introduced at a rate of 370-700 sccm. 10-20 minutes before reaching the growth temperature, 20-100 sccm of bubbling water vapor is introduced. After reaching the growth temperature, 50-100 sccm of hydrogen gas is introduced. After reaching the growth temperature, ethylene gas is introduced at a preset interval of 100-200 sccm. After introducing ethylene gas, the atmosphere inside the tubular furnace is maintained for 10-20 minutes. Throughout the process, the total gas flow rate inside the tubular furnace remains constant and is maintained at 370-700 sccm.

9. The preparation method according to claim 8, characterized in that, The preset duration is 3-8 minutes.

10. The preparation method according to claim 6, characterized in that, In step S3, the argon flow rate is increased to 800-1200 sccm for 3-5 minutes.

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