A method of preventing corrosion of metallic copper, a corrosion-resistant structure of metallic copper
By forming a graphene layer at least 2 atomic layers thick on the surface of a copper substrate, the problem of reduced corrosion resistance caused by weak coupling between graphene and copper is solved, and a highly efficient corrosion protection effect on the copper substrate is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- PEKING UNIV
- Filing Date
- 2023-03-28
- Publication Date
- 2026-07-24
AI Technical Summary
In existing technologies, the weak coupling between graphene and copper at the interface causes interfacial diffusion and electrochemical reactions when preventing copper corrosion, resulting in a decrease in corrosion resistance and an inability to effectively block the penetration of corrosive substances and charge transfer.
A graphene layer with a thickness of at least 2 atomic layers is formed on the surface of a copper substrate. Graphene is deposited by chemical vapor deposition, and the thickness of the graphene layer is controlled by controlling the flow rates of methane and hydrogen. Combined with graphene coupling treatment, the coupling between graphene and copper substrate is enhanced, and interfacial diffusion and charge transfer are reduced.
It effectively blocks charge transfer and electrochemical reactions between the copper substrate and corrosive substances, improves the corrosion resistance of the copper substrate, significantly reduces the formation of copper oxide, and maintains good corrosion resistance.
Smart Images
Figure CN116641038B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of metal corrosion protection technology, and more specifically, to a method for preventing corrosion of copper and a copper corrosion-resistant structure. Background Technology
[0002] Copper is a widely used non-ferrous metal with good electrical and thermal conductivity, ductility, and a low melting point, making it easy to smelt and suitable for large-scale, low-cost industrial production. Therefore, it is widely used in the electrical, light, machinery, construction, and defense industries. A serious problem in copper applications is oxygen corrosion: when copper is exposed to air for extended periods, oxygen and water vapor react with it to form copper oxides, significantly affecting the quality of copper products and even directly impacting their functionality. Currently, to avoid oxygen corrosion, people often use protective layers made of other metals, organic materials, or oxides. However, these often have drawbacks such as poor electrical and thermal conductivity, thickness, poor light transmittance, and incomplete protection. Due to the widespread use of copper, losses due to copper oxidation and corrosion amount to hundreds of millions annually. Therefore, finding a new protective layer material that is low-cost, high-quality, ultra-thin, and has better corrosion resistance is of great practical value and economic and environmental significance. Summary of the Invention
[0003] This application provides a method for preventing corrosion of metallic copper and a corrosion-resistant structure for metallic copper, which can improve the corrosion resistance of metallic copper.
[0004] The embodiments of this application are implemented as follows:
[0005] In a first aspect, this application provides a method for preventing corrosion of metallic copper, comprising: forming a graphene layer with a thickness of at least two atomic layers on the surface of a copper substrate.
[0006] In the above technical solution, the method for preventing corrosion of metallic copper in this application forms a graphene layer with a thickness of at least 2 atomic layers on the surface of the copper substrate, which can reduce the charge transfer between corrosive substances and the copper substrate, making it less likely for the copper substrate to undergo electrochemical reactions through the graphene layer on the surface, thereby improving the corrosion resistance of the copper substrate.
[0007] In conjunction with the first aspect, in a first possible example of the first aspect of this application, the thickness of the graphene formed on the surface of the copper substrate is 2 to 10 atomic layers.
[0008] In conjunction with the first aspect, in a second possible example of the first aspect of this application, the copper substrate is single-crystal copper.
[0009] In the above example, when the copper substrate is monocrystalline copper, the copper substrate has better corrosion resistance.
[0010] In conjunction with the first aspect, in a third possible example of the first aspect of this application, the method of forming at least two layers of graphene on the surface of a copper substrate includes:
[0011] A first graphene layer is obtained by forming a graphene layer with a thickness of one atomic layer on the surface of a copper substrate, and a second graphene layer is obtained by forming a graphene layer with a thickness of one atomic layer on the surface of a copper substrate. Then, at least one second graphene layer is transferred onto the surface of the first graphene layer, and graphene coupling treatment is performed at 300°C to 500°C in an atmosphere including inert gas and hydrogen.
[0012] Optionally, the flow rate of the inert gas in the graphene coupling process is 100 sccm to 1000 sccm, and the flow rate of hydrogen is 5 sccm to 100 sccm.
[0013] Optionally, the graphene coupling treatment time is at least 6 hours.
[0014] Optionally, the graphene coupling treatment time is 6h to 24h.
[0015] In the above example, the method for preventing copper corrosion of this application involves forming a first graphene layer with a thickness of one atomic layer on the surface of a copper substrate and a second graphene layer with a thickness of one atomic layer on the surface of a copper substrate. The second graphene layer is then transferred to the surface of the first graphene layer on the copper substrate, and a bilayer graphene layer is obtained after graphene coupling treatment. The first graphene layer has stronger coupling with the surface of the copper substrate, reducing interfacial diffusion. Simultaneously, the second graphene layer is shielded, resulting in less charge transfer and essentially neutrality, inhibiting electrochemical reactions and thus improving the corrosion resistance of the copper substrate.
[0016] In conjunction with the first aspect, in a fourth possible example of the first aspect of this application, when at least one second graphene layer is transferred onto the surface of the first graphene layer, one second graphene layer is transferred at a time, and after each transfer of a second graphene layer, a graphene coupling process is performed.
[0017] In conjunction with the first aspect, in a fifth possible example of the first aspect of this application, the method of forming a first graphene layer or a second graphene layer with a thickness of one atomic layer on the surface of a copper substrate or a copper-based support includes:
[0018] A first graphene layer or a second graphene layer of one atomic layer thickness is deposited on at least a portion of the surface of a copper substrate or copper-based support by chemical vapor deposition at 1000°C to 1080°C in an atmosphere including methane, hydrogen, and inert gases.
[0019] The flow rate of methane is 0.005 sccm to 0.05 sccm, the flow rate of inert gas is 100 sccm to 1000 sccm, and the flow ratio of methane to hydrogen is 1:200 to 1:1500.
[0020] In conjunction with the first aspect, in a sixth possible example of the first aspect of this application, the method of transferring at least one second graphene layer onto the surface of the first graphite layer includes:
[0021] Before the transfer, a resin layer is first formed on the surface of the second graphene layer, and then the graphene other than the second graphene layer is etched. Then, the copper-based carrier on the back of the second graphene layer is etched to obtain the second graphene layer loaded on the surface of the resin layer. Then, the second graphene layer loaded on the surface of the resin layer is placed on the surface of the first graphene layer for graphene coupling.
[0022] In the above example, the resin layer can serve as a carrier for the second graphene layer after it is separated from the copper-based carrier, allowing the second graphene layer to transfer to the surface of the first graphene layer while maintaining a good morphology.
[0023] In conjunction with the first aspect, in a seventh possible example of the first aspect of this application, the method of forming at least two layers of graphene on the surface of a copper substrate includes:
[0024] A graphene layer of several atomic layers is deposited on at least a portion of the surface of a copper substrate by chemical vapor deposition at 1000°C to 1080°C in an atmosphere containing methane, hydrogen, and inert gases.
[0025] The flow rate of methane is 0.005 sccm to 0.1 sccm, the flow rate of inert gas is 100 sccm to 1000 sccm, and the flow ratio of methane to hydrogen is 1:10 to 1:150.
[0026] In the above example, the method for preventing copper corrosion of this application is to deposit graphene directly on at least a portion of the surface of the copper substrate by chemical vapor deposition, and to control the thickness of the graphene layer by controlling the flow rate of methane and hydrogen. Since the graphene layer is an overlapping of multiple layers of graphene, the defect density that can reach the copper surface is greatly reduced. The graphene layer can block various oxidation pathways, thereby improving the corrosion resistance of the copper substrate.
[0027] In a second aspect, this application provides an example of a copper corrosion-resistant structure, which is prepared according to the above-described method for preventing copper corrosion.
[0028] In the above technical solution, a graphene layer with a thickness of at least 2 atomic layers can reduce the charge transfer between corrosive substances and the copper substrate, making it less likely for the copper substrate to undergo electrochemical reactions through the surface graphene layer, thereby improving the corrosion resistance of the copper substrate.
[0029] In a third aspect, this application provides a copper corrosion-resistant structure comprising a copper substrate and a graphene layer disposed on at least a portion of the surface of the copper substrate, the graphene layer having a thickness of at least two atomic layers.
[0030] In the above technical solution, a graphene layer with a thickness of at least 2 atomic layers can reduce the charge transfer between corrosive substances and the copper substrate, making it less likely for the copper substrate to undergo electrochemical reactions through the surface graphene layer, thereby improving the corrosion resistance of the copper substrate. Attached Figure Description
[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0032] Figure 1 This is a comparison graph showing the relationship between corrosion area and time for the copper anti-corrosion structures of Example 1 and Comparative Example 1 at 200°C.
[0033] Figure 2 SEM images of the copper corrosion-resistant structures of Examples 1-3 and Comparative Example 1 after corrosion at 230 Pa oxygen and 600 °C for 1 s.
[0034] Figure 3 SEM images of the copper corrosion-resistant structures of Examples 1-3 and Comparative Example 1 after corrosion at 230 Pa oxygen and 600 °C for 10 min.
[0035] Figure 4 A comparison diagram showing the corrosion resistance of the copper anti-corrosion structures of Example 1 and Comparative Example 1 after baking at 250°C for 6 hours.
[0036] Figure 5 The graph shows a comparison of the corrosion protection effects of the copper anti-corrosion structures of Examples 1-2 and Comparative Example 1 after baking at 250°C for 0h, 0.5h, 10h and 15h. Detailed Implementation
[0037] Copper is a widely used non-ferrous metal with good electrical and thermal conductivity, ductility, and a low melting point, making it easy to smelt and suitable for large-scale, low-cost industrial production. Therefore, it is widely used in the electrical, light, machinery, construction, and defense industries. A serious problem in copper applications is oxygen corrosion: when copper is exposed to air for extended periods, oxygen and water vapor react with it to form copper oxides, significantly affecting the quality of copper products and even directly impacting their functionality. Currently, to avoid oxygen corrosion, people often use protective layers made of other metals, organic materials, or oxides. However, these often have drawbacks such as poor electrical and thermal conductivity, being thick, having poor light transmittance, and providing incomplete protection. Due to the extremely wide range of copper applications, losses due to copper oxidation and corrosion amount to hundreds of millions annually.
[0038] However, the inventors discovered that in methods using graphene to protect copper from corrosion, the corrosion resistance of graphene decreases sharply at the exposed graphene-copper interface due to interfacial diffusion caused by the weak coupling between graphene and copper, and because graphene is more inert than copper and acts as a cathode in the electrochemical reaction. Currently, although various methods attempt to address this problem, they all rely on the ability of graphene and copper to form a cohesive system or on the smoothness of the copper surface, making them too complex to handle diverse industrial applications.
[0039] Based on the above considerations, in order to improve the corrosion resistance of metallic copper, the inventors, after in-depth research, designed a method to prevent the corrosion of metallic copper. By forming a graphene layer at least two atomic layers thick on the surface of the copper substrate, the charge transfer between corrosive substances and the copper substrate can be weakened, making it difficult for the copper substrate to undergo electrochemical reactions through the surface graphene layer. This effectively blocks the following four corrosion failure pathways: (1) defects introduced during graphene growth; (2) interfacial diffusion caused by weak coupling between graphene and copper; (3) electrochemical reactions between graphene and copper; and (4) penetration of corrosive molecules. Furthermore, this method can prevent further expansion of copper corrosion and maintain good corrosion resistance even when defects exist or are generated during operation.
[0040] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.
[0041] The following is a detailed description of a method for preventing corrosion of metallic copper and a corrosion-resistant structure for metallic copper, based on embodiments of this application:
[0042] This application provides a method for preventing corrosion of metallic copper, which includes: forming a graphene layer with a thickness of at least 2 atomic layers on the surface of a copper substrate.
[0043] Optionally, the thickness of the graphene formed on the surface of the copper substrate is 2 to 10 atomic layers.
[0044] As an example, the thickness of graphene formed on the surface of a copper substrate can be 2, 3, 4, 5, 6, 7, 8, 9, or 10 atomic layers.
[0045] Optionally, the thickness of the graphene formed on the surface of the copper substrate is 2 to 4 atomic layers.
[0046] Optionally, the copper matrix is single-crystal copper.
[0047] When the copper substrate is single-crystal copper, the copper substrate has better corrosion resistance.
[0048] Methods for achieving single-crystalization of polycrystalline copper include:
[0049] Polycrystalline copper is placed on a substrate and placed in a CVD furnace, where it is heated to 1000℃~1080℃ in an atmosphere containing inert gas and hydrogen to perform copper single crystallization treatment.
[0050] As an example, the temperature for copper single crystallization treatment can be 1000℃, 1010℃, 1020℃, 1030℃, 1040℃, 1050℃, 1060℃, 1070℃ or 1080℃.
[0051] Optionally, the flow rate of inert gas in the copper single crystallization process is 100 sccm to 1000 sccm, and the flow rate of hydrogen is 1 sccm to 50 sccm.
[0052] The inert gas used in the copper single crystallization process includes any one or more of helium, argon, xenon, and nitrogen.
[0053] As an example, the flow rate of inert gas in the copper single crystallization process can be 100 sccm, 200 sccm, 300 sccm, 400 sccm, 500 sccm, 600 sccm, 700 sccm, 800 sccm, 900 sccm, or 1000 sccm; the flow rate of hydrogen in the copper single crystallization process can be 1 sccm, 2 sccm, 5 sccm, 8 sccm, 10 sccm, 20 sccm, 30 sccm, 40 sccm, or 50 sccm.
[0054] Optionally, the copper single crystallization treatment time is 10 min to 300 min.
[0055] As an example, the copper single crystallization treatment time can be 10 min, 20 min, 50 min, 80 min, 100 min, 120 min, 150 min, 180 min, 200 min, 220 min, 250 min, 280 min or 300 min.
[0056] Methods for forming at least two layers of graphene on the surface of a copper substrate include:
[0057] A first graphene layer is obtained by forming a graphene layer with a thickness of one atomic layer on the surface of a copper substrate, and a second graphene layer is obtained by forming a graphene layer with a thickness of one atomic layer on the surface of a copper substrate. Then, at least one second graphene layer is transferred onto the surface of the first graphene layer, and graphene coupling treatment is performed at 300°C to 500°C in an atmosphere including inert gas and hydrogen.
[0058] As an example, the temperature for graphene coupling treatment can be 300℃, 320℃, 350℃, 380℃, 400℃, 420℃, 450℃, 480℃ or 500℃.
[0059] Optionally, the flow rate of the inert gas in the graphene coupling process is 100 sccm to 1000 sccm, and the flow rate of hydrogen is 5 sccm to 100 sccm.
[0060] The inert gas used in the graphene coupling process includes any one or more of helium, argon, xenon, and nitrogen.
[0061] As an example, the flow rate of the inert gas in the graphene coupling process can be 100 sccm, 200 sccm, 300 sccm, 400 sccm, 500 sccm, 600 sccm, 700 sccm, 800 sccm, 900 sccm, or 1000 sccm; the flow rate of the hydrogen gas in the graphene coupling process can be 1 sccm, 2 sccm, 5 sccm, 8 sccm, 10 sccm, 20 sccm, 30 sccm, 40 sccm, 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm, or 100 sccm.
[0062] Optionally, the graphene coupling treatment time is at least 6 hours.
[0063] As an example, the graphene coupling treatment time can be 6h, 7h, 8h, 9h, 10h, 11h or 12h.
[0064] Optionally, the graphene coupling treatment time is 6h to 24h.
[0065] A first graphene layer is obtained by forming a 1-atom-thick layer of graphene on the surface of a copper substrate, and a second graphene layer is obtained by forming a 1-atom-thick layer of graphene on the surface of a copper substrate. The second graphene layer is then transferred to the surface of the first graphene layer on the copper substrate, and a bilayer graphene layer is obtained after graphene coupling treatment. The first graphene layer exhibits stronger coupling with the surface of the copper substrate, reducing interfacial diffusion. Simultaneously, the second graphene layer acts as a shield, exhibiting less charge transfer and remaining essentially neutral, thus inhibiting electrochemical reactions and improving the corrosion resistance of the copper substrate.
[0066] Optionally, when transferring at least one second graphene layer onto the surface of the first graphene layer, one second graphene layer is transferred at a time, and after each transfer of a second graphene layer, a graphene coupling process is performed.
[0067] A method for transferring at least one second graphene layer onto the surface of a first graphene layer includes:
[0068] Before the transfer, a resin layer is first formed on the surface of the second graphene layer, and then the graphene other than the second graphene layer is etched. Then, the copper-based carrier on the back of the second graphene layer is etched to obtain the second graphene layer loaded on the surface of the resin layer. Then, the second graphene layer loaded on the surface of the resin layer is placed on the surface of the first graphene layer for graphene coupling.
[0069] The resin layer includes polymethyl methacrylate or polypropylene carbonate.
[0070] Methods for forming a resin layer on the surface of the second graphene layer include:
[0071] The resin solution dissolved in the solvent was spin-coated onto the surface of the second graphene layer and baked at 40℃~160℃ for 1min~5min.
[0072] The solvent includes anisole. When the main component of the resin layer is polymethyl methacrylate (PMMA), the mass fraction of PMMA in the resin solution is 3 wt%–13 wt%, and the baking temperature is 80℃–160℃; when the main component of the resin layer is polypropylene carbonate (PPC), the mass fraction of PPC in the resin solution is 6 wt%–18 wt%, and the baking temperature is 40℃–70℃.
[0073] Alternatively, O2, O3, argon or hydrogen plasma can be used to etch other graphene layers besides the second graphene layer.
[0074] Optionally, the copper-based carrier on the back side of the second graphene layer is etched using a (NH4)2S2O8 solution and a FeCl3 solution with a concentration of 0.05 mol / L to 0.5 mol / L.
[0075] Optionally, the step of etching the copper-based carrier on the back of the second graphene layer is performed in a water bath and dried at 60°C to 90°C before graphene coupling.
[0076] The resin layer can serve as a carrier for the second graphene layer after it is separated from the copper-based carrier, allowing the second graphene layer to transfer to the surface of the first graphene layer while maintaining a good morphology.
[0077] The method for forming a first graphene layer or a second graphene layer with a thickness of one atomic layer on the surface of a copper substrate or copper-based carrier includes:
[0078] A first or second graphene layer of one atomic layer thickness is deposited on at least a portion of the surface of a copper substrate or copper-based support at 1000°C to 1080°C in an atmosphere containing methane, hydrogen, and inert gases, followed by continued introduction of methane and hydrogen gases and natural cooling at atmospheric pressure.
[0079] Optionally, the flow rate of methane is 0.005 sccm to 0.05 sccm, the flow rate of inert gas is 100 sccm to 1000 sccm, and the flow ratio of methane to hydrogen is 1:200 to 1:1500.
[0080] As an example, the flow rate of methane can be 0.005 sccm, 0.008 sccm, 0.01 sccm, 0.02 sccm, 0.03 sccm, 0.04 sccm, or 0.05 sccm; the flow rate ratio of methane to hydrogen can be 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1:800, 1:900, 1:1000, 1:1100, 1:1200, 1:1300, 1:1400, or 1:1500.
[0081] Optionally, the deposition time is 10 min to 30 min.
[0082] As an example, the deposition time can be 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min or 30 min.
[0083] One method for forming at least two layers of graphene on the surface of a copper substrate includes:
[0084] A graphene layer of several atomic layers is deposited on at least a portion of the surface of a copper substrate by chemical vapor deposition at 1000°C to 1080°C in an atmosphere containing methane, hydrogen, and inert gases. Then, methane and hydrogen are continuously introduced, and the substrate is allowed to cool naturally at atmospheric pressure.
[0085] The flow rate of methane is 0.005 sccm to 0.1 sccm, the flow rate of inert gas is 100 sccm to 1000 sccm, and the flow ratio of methane to hydrogen is 1:10 to 1:150.
[0086] As an example, the flow rate of methane can be 0.005 sccm, 0.008 sccm, 0.01 sccm, 0.02 sccm, 0.03 sccm, 0.04 sccm, 0.05 sccm, 0.06 sccm, 0.07 sccm, 0.08 sccm, 0.09 sccm, or 0.1 sccm; the flow rate ratio of methane to hydrogen can be 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, 1:100, 1:110, 1:120, 1:130, 1:140, or 1:150.
[0087] Optionally, the deposition time is 10 min to 300 min.
[0088] As an example, the deposition time can be 10 min, 20 min, 50 min, 80 min, 100 min, 120 min, 150 min, 180 min, 200 min, 220 min, 250 min, 280 min, or 300 min.
[0089] The method for preventing corrosion of metallic copper in this application involves forming a graphene layer with a thickness of at least two atomic layers on the surface of a copper substrate. This reduces charge transfer between corrosive substances and the copper substrate, making it less likely for the copper substrate to undergo electrochemical reactions through the surface graphene layer, thereby improving the corrosion resistance of the copper substrate.
[0090] This application also provides a copper corrosion-resistant structure, which is prepared according to the above-described method for preventing copper corrosion.
[0091] A graphene layer at least two atomic layers thick can reduce charge transfer between corrosive substances and the copper substrate, making it less likely for the copper substrate to undergo electrochemical reactions through the surface graphene layer, thereby improving the corrosion resistance of the copper substrate.
[0092] The anti-corrosion structure for metallic copper includes a copper substrate and a graphene layer disposed on at least a portion of the surface of the copper substrate, wherein the thickness of the graphene layer is at least 2 atomic layers.
[0093] The following describes in further detail a method for preventing corrosion of metallic copper and a corrosion-resistant structure for metallic copper, in conjunction with embodiments of the present application.
[0094] Example 1
[0095] This application provides a method for preventing corrosion of metallic copper, which includes the following steps:
[0096] S1, Copper Single Crystallization Treatment
[0097] A 25μm thick rolled copper foil was placed on a quartz substrate and placed in a CVD furnace. It was heated to 1040℃ in an atmosphere of 500sccm Ar and 10sccm H2 and held at 1040℃ for 120min to make the polycrystalline copper foil single crystallize.
[0098] S2. Forming a graphene layer with a thickness of one atomic layer on the surface of the copper-based carrier and the copper substrate.
[0099] At least two 25 μm thick monocrystalline rolled copper foils were placed on a quartz substrate and placed in a CVD furnace. Graphene layers of one atomic layer thickness were deposited on at least a portion of the surface of the monocrystalline rolled copper foils for 20 min at 1040 °C in an atmosphere of 0.01 sccm CH4, 10 sccm H2, and 500 sccm Ar. Methane and hydrogen were then introduced, and the mixture was allowed to cool naturally at atmospheric pressure.
[0100] S3, graphene layer coupling
[0101] An 8 wt% polymethyl methacrylate (PMMA) anisole solution was spin-coated onto the graphene layer on the front side of a copper substrate and baked at 120 °C for 2 min to obtain a PMMA layer. Then, O2 plasma was used to completely etch the graphene on the back side of the copper substrate. Next, the copper substrate was etched in a water bath using a 0.1 mol / L (NH4)2S2O8 solution to obtain a graphene layer loaded on the surface of the PMMA layer. The graphene layer loaded on the PMMA layer was then smoothly placed on the surface of the graphene layer on the copper substrate, with the two graphene layers in direct contact. It was then removed from the water bath and dried at 80 °C. Finally, it was annealed at 400 °C for 10 h in an atmosphere of 300 sccm Ar and 20 sccm H2 to remove the PMMA layer and couple the two graphene layers, obtaining a bilayer graphene layer.
[0102] Example 2
[0103] This application provides a method for preventing corrosion of metallic copper. In Example 1, after coupling two graphene layers to obtain a bilayer graphene layer, a graphene layer loaded on the surface of a polymethyl methacrylate layer is smoothly placed on the surface of the bilayer graphene layer on the copper substrate, with the two graphene layers in direct contact. Then, it is removed from the water bath and dried at 80°C. Finally, it is annealed at 400°C for 10 hours in an atmosphere of 300 sccm Ar and 20 sccm H2 to remove the polymethyl methacrylate layer and couple the two graphene layers to obtain a trilayer graphene layer.
[0104] Example 3
[0105] This application provides a method for preventing corrosion of metallic copper. In Example 2, after coupling two graphene layers to obtain a three-layer graphene layer, a graphene layer loaded on the surface of a polymethyl methacrylate layer is smoothly placed on the surface of the three-layer graphene layer on the copper substrate, with the two graphene layers in direct contact. Then, it is removed from the water tank and dried at 80°C. Finally, it is annealed at 400°C for 10 hours in an atmosphere of 300 sccm Ar and 20 sccm H2 to remove the polymethyl methacrylate layer and couple the two graphene layers to obtain a four-layer graphene layer.
[0106] Example 4
[0107] This application provides a method for preventing corrosion of metallic copper, which includes the following steps:
[0108] S1, Copper Single Crystallization Treatment
[0109] A 25μm thick rolled copper foil was placed on a quartz substrate and placed in a CVD furnace. It was heated to 1040℃ in an atmosphere of 500sccm Ar and 10sccm H2 and held at 1040℃ for 120min to make the polycrystalline copper foil single crystallize.
[0110] S2. Forming a graphene layer with a thickness of one atomic layer on the surface of the copper-based carrier and the copper substrate.
[0111] A 25 μm thick monocrystalline rolled copper foil was placed on a quartz substrate and placed in a CVD furnace. First, at least a portion of the surface of the monocrystalline rolled copper foil was deposited for 10 min at 1040 °C in an atmosphere of 0.01 sccm CH4, 20 sccm H2 and 500 sccm Ar. Then, at least a portion of the surface of the monocrystalline rolled copper foil was deposited for 30 min at 1040 °C in an atmosphere of 0.05 sccm CH4, 50 sccm H2 and 500 sccm Ar to form a graphene layer with a thickness of 2 atomic layers. Methane and hydrogen were then introduced and the substrate was allowed to cool naturally at atmospheric pressure to obtain a bilayer graphene layer.
[0112] Comparative Example 1
[0113] This application provides a comparative example of a method for preventing corrosion of metallic copper, which includes the following steps:
[0114] S1, Copper Single Crystallization Treatment
[0115] A 25μm thick rolled copper foil was placed on a quartz substrate and placed in a CVD furnace. It was heated to 1040℃ in an atmosphere of 500sccm Ar and 10sccm H2 and held at 1040℃ for 120min to make the polycrystalline copper foil single crystallize.
[0116] S2. Forming a graphene layer with a thickness of one atomic layer on the surface of the copper-based carrier and the copper substrate.
[0117] A 25 μm thick monocrystalline rolled copper foil was placed on a quartz substrate and placed in a CVD furnace. At least a portion of the surface of the monocrystalline rolled copper foil was deposited for 20 min at 1040 °C in an atmosphere of 0.01 sccm CH4, 10 sccm H2 and 500 sccm Ar to form a graphene layer with a thickness of 1 atomic layer. Methane and hydrogen were then introduced and the mixture was allowed to cool naturally at atmospheric pressure to obtain a monolayer graphene layer.
[0118] Experimental Example 1
[0119] The surface potential and nano-angle-resolved photoelectron spectra of the graphene layers in Example 1 and Comparative Example 1 were measured using a Kelvin probe force microscope and a nano-angle-resolved photoelectron spectrometer, respectively. The results are shown in Table 1.
[0120] Table 1. Surface potential and Dirac point shift of graphene layers in Example 1 and Comparative Example 1.
[0121] Surface potential 78mV -57mV Dirac point moved down 0.27eV 0.15eV
[0122] As shown in Table 1, Kelvin probe atomic force microscopy measurements indicate that the surface potential of the bilayer graphene layer in Example 1 is approximately 135 mV higher than that of the monolayer graphene layer in Comparative Example 1, indicating that the bilayer graphene layer has significantly more doped electrons. Nanoscale angle-resolved photoelectron spectroscopy results also show that the monolayer graphene layer on Cu is electron-doped, with the Fermi level shifted upwards by approximately 0.15 eV. However, for the bilayer graphene layer, the transferred electrons cause the Fermi level to shift upwards by approximately 0.2 eV, and the electrons are mainly doped in the bottom layer, while the top layer is almost charge-neutral. First-principles differential charge density wave calculations also confirm a significantly enhanced coupling between the bottom layer of the bilayer graphene and copper, while the top layer of graphene is approximately charge-neutral. This large Fermi level shift and unique electron distribution strengthen the coupling between the bottom graphene and Cu, thereby suppressing interfacial diffusion. More importantly, the top layer of graphene is almost completely doped due to the shielding effect, resulting in a significantly reduced active electron density on the surface of the top layer. Therefore, O2 is more difficult to reduce to O. 2- And O 2- The diffusion of the graphene is also confined to the vertical direction, thereby mitigating the galvanic cell reaction on the exposed Cu surface. In this way, four failure pathways of the graphene coating are blocked: impermeability to corrosive molecules, inhibition of electrochemical reactions, reduction of intrinsic defect density, and blockage of interfacial diffusion. The synergistic effect of all four factors results in the excellent corrosion resistance of the multilayer graphene layer.
[0123] Experimental Example 2
[0124] The oxidized copper surface was observed using an optical microscope. Brightness was used as the standard to distinguish between oxidized and unoxidized areas. The areas of both were statistically analyzed. A comparison graph showing the corrosion area versus time at 200°C for the copper anti-corrosion structures of Example 1 and Comparative Example 1 was obtained. The results are shown below. Figure 1 As shown.
[0125] Depend on Figure 1 The bilayer graphene layer can be epitaxially obtained and still maintains a copper oxidation rate of less than 5% after 1000 hours at 200℃. Moreover, the oxidation rate protected by the bilayer graphene layer is 5 orders of magnitude lower than that of the monolayer graphene layer.
[0126] Experimental Example 3
[0127] In-situ environmental scanning microscopy was used to observe the oxidation process. SEM images of the copper corrosion-resistant structures of Examples 1-3 and Comparative Example 1 after corrosion at 230 Pa oxygen and 600 °C for 1 s and 10 min were obtained, respectively. Figures 2-3 As shown.
[0128] Depend on Figures 2-3 It can be seen that double-layer, triple-layer, and quadruple-layer graphene can all effectively protect the surface of copper, while single-layer graphene is completely destroyed within 1 second, revealing the morphology of copper oxide.
[0129] Test Example 4
[0130] Using visual observation, the corrosion resistance of the copper anti-corrosion structures in Example 1 and Comparative Example 1 after baking at 250°C for 6 hours was compared, as shown in the following figures. Figure 4 As shown.
[0131] Depend on Figure 4 It can be seen that the area covered by the single-layer graphene layer has turned black and dark, proving that the surface has been covered with copper oxide, while the area covered by the double-layer graphene layer still retains the brightness of copper.
[0132] Experimental Example 5
[0133] The oxidized copper surface was observed using an optical microscope. Comparative images of the corrosion resistance of the copper anti-corrosion structures in Examples 1-2 and Comparative Example 1 after baking at 250℃ for 0h, 0.5h, 10h, and 15h were obtained. Figure 5 As shown.
[0134] In summary, the method and anti-corrosion structure for preventing copper corrosion according to the embodiments of this application can protect the copper substrate for more than 5 years at room temperature and normal humidity, and can protect copper for more than 1000 hours at 200°C or more than 6 hours at 250°C. Furthermore, the method for preventing copper corrosion according to the embodiments of this application has no requirements on the crystal plane index, flatness, or interlayer rotation angle of the copper bilayer graphene, and all exhibit excellent anti-corrosion effects.
[0135] The above description is merely a specific embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for preventing corrosion of metallic copper, characterized in that, The method for preventing corrosion of metallic copper includes: forming a graphene layer with a thickness of at least 2 atomic layers on the surface of a copper substrate; The graphene layer includes a first graphene layer disposed on the surface of the copper substrate and at least one second graphene layer disposed on the surface of the first graphene layer facing away from the copper substrate. The method for forming the first graphene layer and the second graphene layer on the surface of the copper substrate includes: forming a graphene layer with a thickness of one atomic layer on the surface of the copper substrate to obtain the first graphene layer, and forming a graphene layer with a thickness of one atomic layer on the surface of the copper substrate to obtain the second graphene layer, then transferring at least one second graphene layer onto the surface of the first graphene layer, and performing graphene coupling treatment at 300°C to 500°C for at least 6 hours in an atmosphere including inert gas and hydrogen.
2. The method for preventing corrosion of metallic copper according to claim 1, characterized in that, The thickness of the graphene formed on the surface of the copper substrate is 2 to 10 atomic layers.
3. The method for preventing corrosion of metallic copper according to claim 1, characterized in that, The copper matrix is single-crystal copper.
4. The method for preventing corrosion of metallic copper according to claim 1, characterized in that, The flow rate of the inert gas in the graphene coupling process is 100 sccm to 1000 sccm, and the flow rate of the hydrogen gas is 5 sccm to 100 sccm.
5. The method for preventing corrosion of metallic copper according to claim 1, characterized in that, The graphene coupling treatment time is 6h~24h.
6. The method for preventing corrosion of metallic copper according to claim 1, characterized in that, When transferring at least one second graphene layer onto the surface of the first graphene layer, one second graphene layer is transferred at a time, and the graphene coupling process is performed after each transfer of a second graphene layer.
7. The method for preventing corrosion of metallic copper according to claim 1, characterized in that, A method for forming a first graphene layer or a second graphene layer with an atomic layer thickness on the surface of the copper substrate or the copper-based support includes: The first graphene layer or the second graphene layer, with a thickness of one atomic layer, is deposited on at least a portion of the surface of the copper substrate or the copper-based support by chemical vapor deposition at 1000°C to 1080°C in an atmosphere including methane, hydrogen and inert gas. The flow rate of methane is 0.005 sccm to 0.05 sccm, the flow rate of inert gas is 100 sccm to 1000 sccm, and the flow ratio of methane to hydrogen is 1:200 to 1:1500.
8. The method for preventing corrosion of metallic copper according to claim 1, characterized in that, A method for transferring at least one second graphene layer onto the surface of the first graphene layer includes: Before the transfer, a resin layer is first formed on the surface of the second graphene layer, and then the graphene other than the second graphene layer is etched. Then, the copper-based carrier on the back side of the second graphene layer is etched to obtain the second graphene layer loaded on the surface of the resin layer. Then, the second graphene layer loaded on the surface of the resin layer is placed on the surface of the first graphene layer for graphene coupling treatment.
9. The method for preventing corrosion of metallic copper according to claim 1, characterized in that, A method for forming at least two graphene layers on the surface of the copper substrate includes: A graphene layer with a thickness of at least 2 atomic layers is formed by chemical vapor deposition at least twice on at least a portion of the surface of the copper substrate in an atmosphere including methane, hydrogen and inert gas at 1000°C to 1080°C. The flow rate of methane is 0.005 sccm to 0.1 sccm, the flow rate of inert gas is 100 sccm to 1000 sccm, and the flow ratio of methane to hydrogen is 1:10 to 1:
150.
10. A corrosion-resistant structure for metallic copper, characterized in that, The copper corrosion-resistant structure is prepared by the method for preventing copper corrosion according to any one of claims 1 to 9.