Method for dispersing metal catalyst nanoparticles in growth of carbon nanotubes
By using the dehydration and wrinkle properties of photoresist during the growth of carbon nanotubes, the dispersion of catalyst particles is achieved, and the problem of uneven diameter and wall count of carbon nanotubes is solved, and its performance and growth efficiency are improved. .
Patent Information
- Application Number
- CN202411502753.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-02-14
AI Technical Summary
During the growth of carbon nanotubes, the agglomeration of metal catalyst nanoparticles leads to uneven diameters and wall counts of carbon nanotubes, affecting its performance.
The carbon nanotubes were grown by spin-coating photoresist on the substrate surface and drying, depositing a film of metal catalyst, annealing, and passing the reaction gas at high temperature. The dehydration and wrinkle properties of the photoresist are used to prevent the agglomeration of the metal film and the dispersion of the catalyst particles.
It effectively reduces the diameter and wall count of carbon nanotubes, improves its uniformity and density, enhances the growth efficiency and performance of carbon nanotubes, while simplifying the preparation process and reducing costs.
Smart Images
Figure CN119430157A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of preparation of carbon nano materials, in particular to a method for dispersing metal catalyst nano particles in the growth of carbon nano tubes. Background Art
[0002] Carbon nanotubes have a wide range of application prospects in the fields of electronics, energy, composite materials, etc. due to their unique physical and chemical properties. Among them, the design and preparation of metal catalysts is an important link in the controlled growth of carbon nanotube structures.
[0003] However, during the growth of carbon nanotubes, the agglomeration of metal catalyst nanoparticles can lead to uneven diameter and wall number of carbon nanotubes, thereby affecting their performance. Therefore, developing a method for effectively dispersing metal catalyst nanoparticles is of great significance for improving the quality of carbon nanotubes. Common technical means currently include: depositing a porous material barrier layer such as aluminum oxide on the substrate surface, selecting alloy catalysts such as NiPt, carbide solid catalysts such as titanium carbide, and using a dispersion liquid spin coating method. Summary of the invention
[0004] The purpose of the present invention is to provide a method for effectively dispersing metal catalyst nanoparticles during the growth of carbon nanotubes to reduce the diameter and wall number of carbon nanotubes and increase the density of carbon nanotubes, thereby improving their performance.
[0005] To achieve the above object, the present invention provides a method for dispersing catalyst metal particles during carbon nanotube growth, characterized in that it comprises the following steps:
[0006] 1) Clean the substrate to remove impurities and contaminants on the surface;
[0007] 2) Spin-coat a layer of photoresist on the substrate surface and dry it;
[0008] 3) Depositing a metal catalyst film on the surface of the substrate with the photoresist;
[0009] 4) performing catalyst annealing treatment on the substrate;
[0010] 5) Introduce reaction gas to grow carbon nanotubes.
[0011] Optionally, the substrate in step 1 may be one of silicon, magnesium oxide, sapphire, quartz, and diamond.
[0012] Optionally, the type of photoresist in step 2 can be one of positive photoresist and negative photoresist, the drying temperature is 100° C.-200° C., and the baking time is 1-10 min.
[0013] Optionally, the method for depositing the metal catalyst film in step 3 is one of magnetron sputtering, electron beam evaporation, and thermal evaporation; the type of catalyst is one or more combinations of nickel, iron, and cobalt.
[0014] Optionally, the equipment used for the annealing treatment in step 4 is one of a high temperature annealing furnace, a plasma chemical vapor deposition device, and a physical vapor deposition device, the annealing time is 5 min-15 min, and the annealing temperature is 600°C-650°C.
[0015] Optionally, the carbon nanotubes grown in step 5 may be vertical carbon tubes, horizontal carbon tubes, or a combination thereof.
[0016] The key of the present invention is to utilize the characteristic that the photoresist will be dehydrated and wrinkled at high temperature, effectively preventing the agglomeration of the metal film in the annealing stage, thereby realizing the effective dispersion of the metal catalyst nanoparticles.
[0017] Compared with the prior art, the present invention has the following significant advantages: 1) the diameter and wall number of carbon nanotubes are reduced, and the uniformity of carbon nanotubes is improved; 2) the density of carbon nanotubes is increased, and the growth efficiency of carbon nanotubes is improved; 3) by using photoresist as a dispersion medium, the preparation process is simplified and the cost is reduced.
[0018] The present invention will be further explained in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is the microscopic morphology of dehydration wrinkles of photoresist after annealing.
[0020] Figure 2 This is a scanned image of metal catalyst nanoparticles during the growth of carbon nanotubes.
[0021] Figure 3 It is a process flow chart of the present invention. DETAILED DESCRIPTION
[0022] Example 1
[0023] 1. First, ultrasonically clean the substrate using acetone, ethanol, and deionized water in sequence to ensure that its surface is clean and free of impurities.
[0024] 2. Then, a layer of positive photoresist AZ4620 was spin-coated on the substrate and baked at 150°C for 10 min to remove the solvent and ensure the uniformity and adhesion of the photoresist layer.
[0025] 3. Then, a magnetron sputtering device is used to deposit 10nm of metallic iron catalyst on the surface of the substrate with the photoresist.
[0026] 4. The catalyst is then annealed in a high temperature annealing furnace at a temperature of 600°C for 5 minutes.
[0027] 5. Finally, 40 sccm of methane and 80 sccm of hydrogen were introduced into the chemical vapor deposition apparatus to grow vertical carbon nanotubes at a temperature of 650°C for 1 hour.
[0028] Example 2
[0029] 1. First, ultrasonically clean the substrate using acetone, ethanol, and deionized water in sequence to ensure that its surface is clean and free of impurities.
[0030] 2. Then, a layer of positive photoresist AZ4620 was spin-coated on the substrate and baked at 150°C for 10 min to remove the solvent and ensure the uniformity and adhesion of the photoresist layer.
[0031] 3. Then, a magnetron sputtering device is used to deposit a 10nm thick metal cobalt catalyst on the surface of the substrate with the photoresist.
[0032] 4. The catalyst is then annealed in a high temperature annealing furnace at a temperature of 600°C for 5 minutes.
[0033] 5. Finally, 50 sccm of methane and 100 sccm of hydrogen were introduced into the chemical vapor deposition apparatus to grow vertical carbon nanotubes at a temperature of 650°C for 20 min.
[0034] Example 3
[0035] 1. First, ultrasonically clean the substrate using acetone, ethanol, and deionized water in sequence to ensure that its surface is clean and free of impurities.
[0036] 2. Then, a layer of negative photoresist is spin-coated on the substrate and baked at 150°C for 10 minutes to remove the solvent and ensure the uniformity and adhesion of the photoresist layer.
[0037] 3. Then, an electron beam evaporation device is used to deposit a 10nm thick metal nickel catalyst on the surface of the substrate with the photoresist.
[0038] 4. The catalyst is then annealed in a high temperature annealing furnace at a temperature of 600°C for 10 minutes.
[0039] 5. Finally, 40 sccm of acetylene and 80 sccm of hydrogen were introduced into the chemical vapor deposition apparatus to grow horizontal carbon nanotubes at a temperature of 650°C for 1 hour.
Claims
1. A method for dispersing metal catalyst nanoparticles during carbon nanotube growth, characterized in that: The following steps are involved: 1) Clean the substrate to remove impurities and contaminants on the surface; 2) Spin-coat a layer of photoresist on the substrate surface and dry it; 3) Depositing a metal catalyst film on the surface of the substrate with the photoresist; 4) performing catalyst annealing treatment on the substrate; 5) Introduce reaction gas to grow carbon nanotubes.
2. The method for dispersing metal catalyst nanoparticles during carbon nanotube growth according to claim 1, characterized in that: The substrate in step 1) is one of silicon, magnesium oxide, sapphire, quartz and diamond.
3. The method for dispersing metal catalyst nanoparticles during carbon nanotube growth according to claim 1, characterized in that: In step 2), the type of photoresist is one of positive photoresist and negative photoresist, the drying temperature is 100° C.-200° C., and the baking time is 1-10 min.
4. The method for dispersing metal catalyst nanoparticles during carbon nanotube growth according to claim 1, characterized in that: In step 3), the method for depositing the metal catalyst film is one of magnetron sputtering, electron beam evaporation, and thermal evaporation; the type of catalyst is one or more combinations of nickel, iron, and cobalt.
5. The method for dispersing metal catalyst nanoparticles during carbon nanotube growth according to claim 1, characterized in that: The equipment used for annealing treatment in step 4) is one of a high temperature annealing furnace, a plasma chemical vapor deposition device, and a physical vapor deposition device. The annealing time is 5 min-15 min, and the annealing temperature is 600° C.-650° C.
6. The method for dispersing metal catalyst nanoparticles during carbon nanotube growth according to claim 1, characterized in that: The carbon nanotubes grown in step 5) are one or more combinations of vertical carbon tubes and horizontal carbon tubes.