Graphene oxide coating-copper-based composite material and preparation method and application thereof

Abstract

The invention relates to the technical field of metal surface treatment, and provides a graphene oxide coating-copper-based composite material and a preparation method and application thereof. An interface chemical engineering strategy is adopted, oxygen-containing functional groups such as-OH and-COOH are modified on the surface of a copper substrate through solvothermal reaction, then the obtained functionalized copper substrate is immersed in graphene oxide dispersion liquid, and graphene oxide nanosheets are dried and induced to coat the surface of the copper substrate. The oxygen-containing functional groups on the surface of the functionalized copper substrate and the oxygen-containing functional groups on the surface of the graphene generate chemical interaction, so that the interface bonding strength of the graphene oxide coating and the copper substrate can be effectively improved, the graphene oxide coating can continuously generate a lubricating effect, the friction coefficient is kept below 0.2 for a long time, meanwhile, the wear resistance of the material is enhanced, and the service life of the material is prolonged. The wear rate is obviously reduced compared with a pure copper substrate. The problems that a traditional graphene oxide coating is easy to peel off and loses efficacy in lubrication due to weak interface bonding are solved, and the application prospect is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of metal surface treatment, and in particular to a graphene oxide coating-copper-based composite material and a preparation method and application thereof. Background Art

[0002] Metallic copper is widely used in key friction components such as precision electronic connectors, sliding bearings, and collector rings of high-speed trains due to its excellent electrical conductivity, thermal conductivity, and processing properties. However, the inherent low hardness and poor wear resistance of copper-based materials make them prone to adhesive wear, oxidative corrosion, and unstable contact resistance under long-term friction conditions, which seriously affects the service life and reliability of the device. In order to improve the tribological properties of the surface of copper-based materials, researchers generally use surface coating technology, that is, by preparing a lubricating coating on the surface of copper-based materials to improve their lubricity and wear resistance. Among them, two-dimensional nanomaterials (such as graphene oxide) are regarded as ideal solid lubricating materials because of their ultra-thin layered structure, high chemical stability, and self-lubricating properties.

[0003] However, currently graphene oxide coatings are mostly prepared on the surface of copper-based materials through spin coating, spray coating and other methods. The bonding between graphene oxide coatings and copper substrates mostly relies on physical adsorption, resulting in low bonding strength between the coating and the substrate, and easy peeling and failure during friction. Summary of the Invention

[0004] In light of this, the present invention provides a graphene oxide coating-copper-based composite material, its preparation method, and its application. In the graphene oxide coating-copper-based composite material prepared by the present invention, the graphene oxide coating and the copper substrate are bonded via chemical adsorption, resulting in a high bonding strength and resistance to flaking and failure during friction.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A method for preparing a graphene oxide coating-copper-based composite material comprises the following steps:

[0007] Immersing the copper substrate in a functionalization treatment solution for a solvent thermal reaction to obtain a functionalized copper substrate; the functionalization treatment solution comprises a solute and a solvent, wherein the solute is formate and the solvent comprises water, N,N-dimethylformamide and oleylamine;

[0008] The functionalized copper substrate is immersed in a graphene oxide dispersion and then dried to obtain a graphene oxide coating-copper-based composite material.

[0009] Preferably, the volume fraction of water in the solvent is 7-8%, the volume fraction of N,N-dimethylformamide is 85-86%, and the volume fraction of oleylamine is 7-8%; and the content of formate in the functionalized treatment solution is 14-15 mg / mL.

[0010] Preferably, the temperature of the solvent thermal reaction is 160-200° C., and the time is 16-24 hours.

[0011] Preferably, the solvent thermal reaction is carried out in a reactor, and the filling amount of the functionalization treatment liquid in the reactor is 20-30% of the volume of the reactor.

[0012] Preferably, the graphene oxide in the graphene oxide dispersion is graphene oxide nanosheets; the number of layers of the graphene oxide nanosheets is 1 to 30; and the concentration of the graphene oxide dispersion is 0.1 to 1 mg / mL.

[0013] Preferably, the drying is vacuum drying; the drying temperature is 30 to 80° C., and the drying time is 12 to 48 hours.

[0014] The present invention also provides a graphene oxide coating-copper-based composite material prepared by the preparation method described in the above scheme, comprising a functionalized copper substrate and a graphene oxide coating supported on the surface of the functionalized copper substrate by chemical adsorption.

[0015] Preferably, the loading amount of the graphene oxide coating in the graphene oxide coating-copper-based composite material is 0.1 to 0.7 mg / cm 2 .

[0016] The present invention also provides the use of the graphene oxide coating-copper-based composite material described in the above solution as a friction component.

[0017] Preferably, the friction component includes a precision electronic connector, a sliding bearing or a train collector ring.

[0018] The present invention provides a method for preparing a graphene oxide coating-copper-based composite material, comprising the following steps: immersing a copper substrate in a functionalized treatment solution for a solvothermal reaction to obtain a functionalized copper substrate; the functionalized treatment solution comprising a solute and a solvent, wherein the solute is a formate and the solvent comprises water, N,N-dimethylformamide, and oleylamine; immersing the functionalized copper substrate in a graphene oxide dispersion, and then drying to obtain the graphene oxide coating-copper-based composite material. The present invention adopts an interfacial chemical engineering strategy to modify oxygen-containing functional groups such as -OH and -COOH on the surface of the copper substrate through a solvothermal reaction. Through the chemical interaction between these oxygen-containing functional groups and the oxygen-containing functional groups on the graphene surface, the interfacial bonding strength between the graphene oxide coating and the copper substrate coating is effectively improved, thereby achieving stable coating of graphene oxide nanosheets on the surface of the copper substrate. The interfacial bonding strength is significantly higher than that of a physical coating method, thereby enabling the graphene oxide coating to continuously lubricate the copper substrate, maintaining the friction coefficient below 0.2 for a long time, and enhancing the wear resistance of the material, with the wear rate significantly reduced compared to a pure copper substrate.

[0019] The results of the examples show that the graphene oxide coating-copper-based composite material prepared by the present invention has a dense structure and few defects, and the interface bonding strength of the graphene oxide coating is improved by 51.3% compared with the physically adsorbed graphene oxide coating. At the same time, the graphene oxide coating-copper-based composite material prepared by the present invention was subjected to a wear test for 3 hours under a load of 15N, a linear speed of 3.0m / min, and a radius of 4mm disc wear conditions. Its friction coefficient remained below 0.2 and the wear rate was 2.27μm. 3 / (N·mm), which is significantly lower than that of pure copper sample (friction coefficient of about 0.4, wear rate of 8.58μm 3 / (N·mm)) and copper-based material samples with physically adsorbed graphene oxide coating (friction coefficient of about 0.4, wear rate of 7.32 μm 3 / (N·mm)). Furthermore, no graphene oxide residue was observed in the wear morphology of the copper-based material sample coated with physically adsorbed graphene oxide. Furthermore, during the friction and wear test, the friction coefficient continued to rise to the same level as that of the pure copper sample. This was attributed to the poor interfacial bonding strength of the coating. However, graphite residue was still observed in the wear morphology of the graphene oxide coating-copper-based composite material prepared by the present invention, further demonstrating that the preparation method of the present invention can provide a strong graphene oxide coating adhesion. Therefore, the present invention effectively solves the problems of easy flaking and lubrication failure caused by weak interfacial bonding in traditional graphene oxide coatings, and can provide a long-lasting wear-reducing effect on metallic copper substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The time-of-flight secondary ion mass spectrometry observation results of -OH on the surface of the functionalized copper substrate in Example 1;

[0021] Figure 2 The time-of-flight secondary ion mass spectrometry observation results of -COOH on the functionalized copper substrate surface in Example 1;

[0022] Figure 3 This is an electron microscope photograph of the interface of the graphene oxide coating on the copper substrate surface in Example 1;

[0023] Figure 4 This is an electron microscope photograph of the interface of the graphene oxide coating on the copper substrate surface in Comparative Example 1;

[0024] Figure 5 The graphene oxide coating and the copper substrate bonding test results in Example 1;

[0025] Figure 6 The graphene oxide coating and the copper substrate bonding test results in Comparative Example 1;

[0026] Figure 7 The relationship between the wear coefficient and time of the GO coating-modified Cu prepared in Example 1, the GO coating-Cu prepared in Comparative Example 1, and the pure copper in Comparative Example 2;

[0027] Figure 8 This is a comparison chart of the wear rates of the GO coating-modified Cu prepared in Example 1, the GO coating-Cu prepared in Comparative Example 1, and the pure copper in Comparative Example 2;

[0028] Figure 9 This is a scanning electron microscope image of the wear scar after the friction and wear test of the GO coating-modified Cu prepared in Example 1;

[0029] Figure 10 This is a scanning electron microscope image of the wear scar after the GO coating-Cu friction and wear test prepared in Comparative Example 1. DETAILED DESCRIPTION

[0030] The present invention provides a method for preparing a graphene oxide coating-copper-based composite material, comprising the following steps:

[0031] Immersing the copper substrate in a functionalization treatment solution for a solvent thermal reaction to obtain a functionalized copper substrate; the functionalization treatment solution comprises a solute and a solvent, wherein the solute is formate and the solvent comprises water, N,N-dimethylformamide and oleylamine;

[0032] The functionalized copper substrate is immersed in a graphene oxide dispersion and then dried to obtain a graphene oxide coating-copper-based composite material.

[0033] The present invention immerses a copper substrate in a functionalization treatment solution to perform a solvent thermal reaction to obtain a functionalized copper substrate. In the present invention, the copper substrate preferably includes a pure copper substrate or a copper alloy substrate; the functionalization treatment solution includes a solute and a solvent, the solute is a formate, and the solvent includes water, N,N-dimethylformamide, and oleylamine; the formate is preferably sodium formate; the water is preferably distilled water; the volume fraction of water in the solvent is preferably 7-8%, specifically 7.14%, the volume fraction of N,N-dimethylformamide is preferably 85-86%, specifically 85.72%, and the volume fraction of oleylamine is preferably 7-8%, specifically 7.14%; the content of formate in the functionalization treatment solution is preferably 14-15 mg / mL, specifically 14.3 mg / mL. The present invention adopts a functionalized treatment liquid and utilizes a solvent thermal method to perform interfacial chemical modification on a copper substrate, wherein formate can react with the copper substrate to introduce oxygen-containing functional groups, such as -OH and -COOH, on the surface of the copper substrate. These oxygen-containing functional groups can produce chemical adsorption with functional groups on the surface of graphene oxide, thereby facilitating enhanced interfacial bonding between the graphene oxide coating and the copper substrate. In the present invention, N,N-dimethylformamide and oleylamine are added to the functionalized treatment liquid to promote copper surface reconstruction and accelerate the reaction rate between the formate and the copper substrate, thereby uniformly modifying the oxygen-containing functional groups on the copper surface.

[0034] In the present invention, the temperature of the solvent thermal reaction is preferably 160-200°C, specifically 160°C, 170°C, 180°C or 200°C, and the time of the solvent thermal reaction is preferably 16-24h, specifically 17h, 18h or 20h; the present invention can provide the temperature conditions and time required for chemical modification by controlling the reaction temperature and time.

[0035] In the present invention, the solvent thermal reaction is preferably carried out in a reactor, the inner lining of the reactor is preferably polytetrafluoroethylene, the outer lining is preferably stainless steel, the volume of the reactor is preferably 50 to 150 mL, more preferably 50 to 100 mL; the filling amount of the functional treatment liquid in the reactor is preferably 20 to 30% of the volume of the reactor, more preferably 25 to 30%; the present invention can provide the reactant concentration and reaction pressure required for chemical modification by controlling the volume of the reactor and the filling amount of the functional treatment liquid. Under solvent thermal conditions, the surface of the copper substrate undergoes slight reconstruction to form some low-coordinated (undersaturated) copper atom sites, which are more likely to form coordination bonds with formate ions. This coordination effect is similar to the interaction between organic ligands and metal ions, thereby generating a chemical modification layer containing oxygen-containing functional groups on the surface of the copper substrate.

[0036] After the solvent thermal reaction is completed, the functionalized copper substrate is preferably taken out and cleaned, and the cleaning agent is preferably alcohol.

[0037] After obtaining the functionalized substrate, the present invention immerses the functionalized copper substrate in a graphene oxide dispersion and then dries it to obtain a graphene oxide coating-copper-based composite material. In the present invention, the graphene oxide in the graphene oxide dispersion is preferably graphene oxide nanosheets; the number of layers of the graphene oxide nanosheets is preferably 1 to 30 layers, more preferably 1 to 20 layers, and further preferably 1 to 10 layers; the concentration of the graphene oxide dispersion is preferably 0.1 to 1 mg / mL, more preferably 0.2 to 0.7 mg / mL, and further preferably 0.3 to 0.5 mg / mL. The present invention ensures the quality of the deposited graphene oxide coating by controlling the concentration of the graphene oxide dispersion and the number of graphene oxide layers. Excessive concentration and number of layers will affect the dispersion effect of the graphene oxide, thereby causing defects in the coating. The present invention has no special requirements for the amount of the graphene oxide dispersion used, as long as it can keep the surface of the copper substrate submerged.

[0038] In the present invention, the drying is preferably vacuum drying; the drying temperature is preferably 30 to 80°C, more preferably 30 to 60°C, and further preferably 35 to 40°C, and the vacuum drying time is preferably 12 to 48 hours, more preferably 12 to 24 hours. During the vacuum drying process, the oxygen-containing functional groups on the surface of the graphene oxide and the oxygen-containing functional groups such as -OH and -COOH on the surface of the functionalized copper substrate chemically interact, thereby adsorbing the graphene oxide on the surface of the copper substrate. By controlling the temperature and time of vacuum drying, the present invention is more conducive to the formation of high-quality coatings. Higher drying temperatures and longer drying times will cause thermal expansion, affecting the bonding of the coating to the substrate and the coating quality.

[0039] The graphene oxide coating prepared by the preparation method provided by the present invention has a dense structure and can form a strong coating interface bonding force with the copper substrate, so that it will not be peeled off and failed under the action of long-term friction load, thereby exerting a long-term lubrication effect and providing excellent wear resistance. At the same time, the preparation method is simple, the parameters are easy to control, and the cost is low.

[0040] The present invention also provides a graphene oxide coating-copper-based composite material prepared by the preparation method described in the above scheme, comprising a functionalized copper substrate and a graphene oxide coating supported on the surface of the functionalized copper substrate by chemical adsorption. In the present invention, the functionalized copper substrate comprises a copper substrate and oxygen-containing functional groups modified on the surface of the copper substrate; the loading amount of the graphene oxide coating in the graphene oxide coating-copper-based composite material is preferably 0.1 to 0.7 mg / cm 2 , more preferably 0.21 to 0.5 mg / cm 2 , more preferably 0.35 to 0.5 mg / cm 2; The present invention controls the loading amount of the graphene oxide coating within the above range, which is more conducive to forming a graphene oxide coating that is tightly bonded to the substrate and continuously maintains the lubricating effect during the friction and wear process.

[0041] The present invention also provides the use of the graphene oxide coating-copper-based composite material described in the above-mentioned solution as a friction component; the friction component includes a precision electronic connector, a sliding bearing, or a train slip ring. Under loads of 1 to 15 N and sliding speeds of 0.6 to 3.5 m / min, the graphene oxide coating-copper-based composite material provided by the present invention maintains a coefficient of friction of ≤ 0.2 for 3 hours, exhibiting excellent lubricity and wear resistance, and possessing broad application prospects in friction components.

[0042] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] The copper substrates used in the following embodiments are all pure copper substrates.

[0044] Example 1

[0045] (1) Functionalization of copper substrate: Dissolve 400 mg of sodium formate in 2 mL of distilled water, then add 24 mL of N,N-dimethylformamide and 2 mL of oleylamine and mix thoroughly to obtain a functionalization solution. Place the functionalization solution in a 100 mL polytetrafluoroethylene-lined stainless steel reactor, place the prepared pure copper substrate, and perform a solvothermal reaction at 180°C for 18 hours. Clean the copper substrate with alcohol after the solvothermal reaction and set aside.

[0046] (2) Preparation of graphene oxide coating: Place the cleaned functionalized copper substrate in a container of suitable size, add 5 mL of 0.5 mg / mL graphene oxide dispersion, and then place it in a vacuum drying oven at 35°C for 12 hours to obtain a graphene oxide coating-copper matrix composite material. The graphene oxide loading is 0.35 mg / cm 2 The prepared sample was recorded as GO-coated-modified Cu.

[0047] Example 2

[0048] (1) Functionalization of copper substrate: Dissolve 400 mg of sodium formate in 2 mL of distilled water, then add 24 mL of N,N-dimethylformamide and 2 mL of oleylamine and mix thoroughly to obtain a functionalization treatment solution. Place the functionalization treatment solution in a 100 mL polytetrafluoroethylene-lined stainless steel reactor, place the prepared pure copper substrate, and perform a solvothermal reaction at 160°C for 17 hours. Clean the copper substrate with alcohol after the solvothermal reaction and set aside.

[0049] (2) Preparation of graphene oxide coating: Place the cleaned functionalized copper substrate in a container of suitable size, add 5 mL of 0.3 mg / mL graphene oxide dispersion, and then place it in a vacuum drying oven at 40°C for 24 hours to obtain a graphene oxide coating-copper matrix composite material. The graphene oxide loading is 0.21 mg / cm 2 The prepared sample was named GO-coated-modified Cu-2.

[0050] Example 3

[0051] (1) Functionalization of copper substrate: Dissolve 400 mg of sodium formate in 2 mL of distilled water, then add 24 mL of N,N-dimethylformamide and 2 mL of oleylamine and mix thoroughly to obtain a functionalization solution. Place the functionalization solution in a 100 mL polytetrafluoroethylene-lined stainless steel reactor, place the prepared pure copper substrate, and perform a solvothermal reaction at 200°C for 20 h. Clean the copper substrate with alcohol after the solvothermal reaction and set aside.

[0052] (2) Preparation of graphene oxide coating: Place the cleaned functionalized copper substrate in a container of suitable size, add 5 mL of 0.7 mg / mL graphene oxide dispersion, and then place it in a vacuum drying oven at 60°C for 12 hours to obtain a graphene oxide coating-copper matrix composite material. The graphene oxide loading is 0.50 mg / cm 2 The prepared sample was named GO-coated-modified Cu-3.

[0053] Comparative Example 1

[0054] Graphene oxide coating: Place the cleaned unmodified copper substrate in a container of suitable size and pour 5 mL of 0.7 mg / mL graphene oxide dispersion into it. Then place it in a vacuum drying oven at 35°C for 12 hours to obtain a copper substrate coated with a strong interface-bound graphene oxide coating. The graphene oxide loading is 0.35 mg / cm 2 The prepared sample was recorded as GO-coated-Cu.

[0055] Comparative Example 2

[0056] A pure copper sample without any surface modification and graphene oxide coating is denoted as Cu.

[0057] Performance Testing

[0058] (1) Observation of the surface of functionalized copper substrate

[0059] The functionalized copper substrate in Example 1 was observed using a time-of-flight secondary ion mass spectrometer. Figure 1 and Figure 2 As shown, Figure 1 The time-of-flight secondary ion mass spectrometry observation results of -OH on the surface of functionalized copper substrate are shown in Figure 2. Figure 2 The results of time-of-flight secondary ion mass spectrometry observation of -COOH on the surface of functionalized copper substrate. Figure 1 and Figure 2 It can be seen that the surface of the copper substrate after chemical modification has a large amount of -OH and -COOH, indicating that the present invention successfully achieves the modification of oxygen-containing functional groups on the surface of the copper substrate, which is conducive to the chemical adsorption of graphene oxide nanosheets to form a graphene oxide coating with strong interfacial bonding.

[0060] (2) Observation of graphene oxide coating morphology

[0061] Figure 3 and Figure 4 The following are electron microscope photos of the interface of graphene oxide coating on the copper substrate surface in Example 1 and Comparative Example 1 respectively. Figure 3 and Figure 4 It can be found that the graphene oxide coating loaded by chemical adsorption in Example 1 is relatively denser and has fewer defects.

[0062] (3) Interface bonding strength test

[0063] The bonding strength between the graphene oxide coating and the copper substrate in Example 1 and Comparative Example 1 was tested using a nano scratch tester. The test conditions were as follows: a load gradually increased from 0 N to 25 N was applied to the GO coating surface for 5 mm. The length and load corresponding to the complete peeling of the GO coating inside the scratch and the complete exposure of the copper substrate were the coating bonding strength. The results are shown in Figure 2. Figure 5 and Figure 6 As shown. Figure 5 and Figure 6 It can be found that the coating bonding forces of the physically coated graphene oxide coating and the graphene oxide coating coated by chemical adsorption are 3.88N and 5.87N, respectively. The interfacial bonding force of the graphene oxide coating coated by chemical adsorption is increased by 51.3%.

[0064] (4) Friction and wear test

[0065] Friction and wear tests were performed on the GO coating-modified Cu prepared in Example 1, the GO coating-Cu prepared in Comparative Example 1, and the pure copper in Comparative Example 2. The test conditions were as follows: load 15 N, linear speed 3 m / min, disc wear radius 4 mm, and friction and wear time 3 h.

[0066] Figure 7 The relationship between the wear coefficient and time of the GO coating-modified Cu prepared in Example 1, the GO coating-Cu prepared in Comparative Example 1 and the pure copper in Comparative Example 2. Figure 7 As can be seen, the wear coefficient of the sample coated with physical graphene oxide (GO coating-Cu) increases with wear time. After 3 hours of wear, its wear coefficient is basically the same as that of the pure copper sample. The wear coefficient of the sample coated with graphene oxide by chemical adsorption (GO coating-modified Cu) remains stable at around 0.2. These results demonstrate that the present invention can significantly increase the interfacial bonding strength between graphene oxide and the copper substrate, which helps the graphene oxide coating maintain its lubricating effect.

[0067] Figure 8 The comparison chart of the wear rates of GO coating-modified Cu prepared in Example 1, GO coating-Cu prepared in Comparative Example 1 and pure copper in Comparative Example 2 is shown. Figure 8 It can be seen that the wear rate of the graphene oxide coating sample (GO coating-modified Cu) coated by chemical adsorption is 2.27 μm 3 / (N·mm), significantly lower than that of pure copper sample (8.58μm 3 / (N·mm)) and physically adsorbed graphene oxide coating samples (7.32 μm 3 The above results indicate that the present invention can continuously exert the lubricating effect of graphite oxide by increasing the interfacial bonding strength between the graphene oxide coating and the copper substrate, thereby providing the copper substrate with more excellent anti-wear performance.

[0068] Figure 9 and Figure 10 The wear marks after the friction and wear test of GO coating-modified Cu prepared in Example 1 and GO coating-Cu prepared in Comparative Example 1 are respectively obtained by scanning electron microscope. Figure 9 and Figure 10The wear scar of the physically applied graphene oxide coating (GO coating-Cu) was severely damaged, with no residual graphene oxide coating. However, the wear scar of the chemically adsorbed graphene oxide coating (GO coating-modified Cu) was smooth and intact, with residual graphene oxide nanosheets, which provide lubrication, remaining on the surface. These results further demonstrate that the present invention can enhance the interfacial bonding strength between the graphene oxide coating and the copper substrate, thereby preventing wear and spalling failure and providing sustained lubrication and wear resistance.

[0069] The interface bonding strength test and friction and wear test were performed on the GO coating-modified Cu-2 prepared in Example 2 and the GO coating-modified Cu-3 prepared in Example 3, and the results were similar to those in Example 1.

[0070] In summary, the present invention solves the problems of easy peeling and lubrication failure caused by weak interface bonding of existing graphene oxide coatings, achieves higher lubrication effect and wear resistance, and has broad application prospects.

[0071] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a graphene oxide coating-copper-based composite material, characterized in that: The following steps are involved: Immersing the copper substrate in a functionalization treatment solution for a solvent thermal reaction to obtain a functionalized copper substrate; the functionalization treatment solution comprises a solute and a solvent, wherein the solute is formate and the solvent comprises water, N,N-dimethylformamide and oleylamine; The functionalized copper substrate is immersed in a graphene oxide dispersion and then dried to obtain a graphene oxide coating-copper-based composite material.

2. The preparation method according to claim 1, characterized in that The volume fraction of water in the solvent is 7-8%, the volume fraction of N,N-dimethylformamide is 85-86%, and the volume fraction of oleylamine is 7-8%. The content of formate in the functionalized treatment solution is 14-15 mg / mL.

3. The preparation method according to claim 1, characterized in that The temperature of the solvent thermal reaction is 160-200° C., and the time is 16-24 hours.

4. The preparation method according to claim 1 or 3, characterized in that The solvent thermal reaction is carried out in a reactor, and the filling amount of the functional treatment liquid in the reactor is 20-30% of the volume of the reactor.

5. The preparation method according to claim 1, characterized in that The graphene oxide in the graphene oxide dispersion is graphene oxide nanosheets; the number of layers of the graphene oxide nanosheets is 1 to 30; and the concentration of the graphene oxide dispersion is 0.1 to 1 mg / mL.

6. The preparation method according to claim 1, characterized in that The drying is vacuum drying; the drying temperature is 30 to 80° C., and the drying time is 12 to 48 hours.

7. The graphene oxide coating-copper-based composite material prepared by the preparation method according to any one of claims 1 to 6, characterized in that: The invention comprises a functionalized copper substrate and a graphene oxide coating loaded on the surface of the functionalized copper substrate through chemical adsorption.

8. The graphene oxide coating-copper-based composite material according to claim 7, characterized in that The loading amount of the graphene oxide coating in the graphene oxide coating-copper-based composite material is 0.1 to 0.7 mg / cm 2 .

9. Use of the graphene oxide coating-copper-based composite material according to claim 7 or 8 as a friction component.

10. The use according to claim 9, characterized in that The friction components include precision electronic connectors, sliding bearings or train collector rings.

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