Copper-containing plating solution and method for plating copper on surface of graphene

Abstract

The invention provides a copper-containing plating solution and a method for plating copper on the surface of graphene, and belongs to the technical field of chemical plating. The copper-containing plating solution provided by the invention comprises copper sulfate pentahydrate, hypophosphite, glyoxylic acid, ethylenediamine tetraacetic acid tetrasodium salt, sodium citrate and deionized water. The glyoxylic acid in the copper-containing plating solution can quickly provide electrons in the initial reaction stage, so that copper ions are quickly nucleated; hypophosphite can continuously reduce copper ions in the plating solution into copper atoms, and continuous growth of a copper layer is achieved; tetrasodium ethylene diamine tetraacetate and copper ions can form a complex with high stability, and the copper ions are slowly released; sodium citrate is used as an auxiliary complexing agent, so that the discharge potential can be adjusted, and the deposition process of copper ions is further optimized, so that compact coating of a to-be-plated copper matrix is realized, and the copper plating effect is effectively improved. Results of the embodiment show that the copper-containing plating solution provided by the invention can form a compactly coated copper layer on the surface of graphene.

Description

Technical Field

[0001] The present invention relates to the technical field of electroless plating solutions, and particularly to a copper-containing plating solution and a method for copper plating on the surface of graphene. Background Art

[0002] Graphene has excellent electrical conductivity, mechanical strength, high specific surface area and other properties, and has extensive and important applications in the fields of electronics, energy, composite materials, sensing, medical treatment, environmental protection, etc. It is a new type of functional material with great potential. At present, the use of graphene as a reinforcing phase in the field of metal materials to improve the mechanical properties of alloy materials has been widely studied. However, there are strong van der Waals interactions between graphene sheets, which will cause graphene to agglomerate during use, resulting in uneven distribution in alloy materials. Moreover, the concentrated distribution of graphene may cause stress concentration or other abnormal failure phenomena.

[0003] In view of the agglomeration phenomenon of graphene, a metal element such as Cu or Ni is usually coated on the surface of graphene to alleviate its agglomeration phenomenon. Commonly used methods for copper plating on the surface of graphene include: chemical reduction method, electrochemical deposition method and thermal evaporation method. Among them, the chemical reduction method has the advantages of low cost, small pollution, non-toxicity, etc. and is widely used. The chemical reduction method for copper plating is a method of reducing copper ions in a copper-containing solution to metallic copper under the action of a reducing agent and depositing it on the surface of a substrate. Currently, hypophosphite is commonly used as a reducing agent for copper plating. However, since copper has no catalytic activity for hypophosphite, the copper coverage rate will be reduced. In order to catalyze the occurrence of redox reactions, Ni, Co and other metal ions need to be introduced into the plating solution. However, the introduced other metal ions will co-precipitate with copper and interfere with the uniform deposition of copper on the surface of graphene, and a dense copper layer cannot be formed on the surface of graphene to solve the agglomeration of graphene. Summary of the Invention

[0004] The purpose of the present invention is to provide a copper-containing plating solution and a method for copper plating on the surface of graphene. The copper-containing plating solution provided by the present invention can form a dense copper layer on the surface of graphene.

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

[0006] The present invention provides a copper-containing plating solution, comprising: copper sulfate pentahydrate, hypophosphite, glyoxylic acid, sodium ethylenediaminetetraacetate, sodium citrate and deionized water.

[0007] Preferably, the concentration of copper sulfate pentahydrate in the copper-containing plating solution is 7.5 - 20 g / L, the concentration of hypophosphite is 30 - 40 g / L, the concentration of glyoxylic acid is 5.25 - 25 mL / L, the concentration of sodium ethylenediaminetetraacetate is 15 - 30 g / L, and the concentration of sodium citrate is 25 - 70 g / L.

[0008] The present invention also provides a method for copper plating on the surface of graphene, comprising the following steps;

[0009] (1) Pretreat the graphene to obtain activated graphene;

[0010] (2) Mix the activated graphene obtained in step (1) with the copper-containing plating solution described in the above technical solution and then perform copper plating; the temperature of the copper plating is 30-60°C.

[0011] Preferably, in step (2), the mass ratio of the activated graphene to the volume of the copper-containing plating solution is 1 g:(0.5-1.5) L.

[0012] Preferably, in step (2), the pH of the copper-containing plating solution is adjusted to 12-14 before copper plating.

[0013] Preferably, the time for copper plating in step (2) is 60-90 min.

[0014] Preferably, the pretreatment in step (1) includes dispersion treatment, degreasing treatment, roughening treatment, sensitization treatment and activation treatment carried out in sequence.

[0015] Preferably, the roughening agent used for the roughening treatment is a sodium hydroxide solution.

[0016] Preferably, the sensitizer used for the sensitization treatment is an aqueous solution of stannous chloride and hydrogen chloride; the concentration of stannous chloride in the sensitizer is 8-12 g / L; the concentration of hydrogen chloride in the sensitizer is 60-100 mL / L.

[0017] Preferably, the activator used for the activation treatment is an aqueous solution of palladium chloride and hydrogen chloride; the concentration of palladium chloride in the activator is 0.8-1.2 g / L; the concentration of hydrogen chloride in the activator is 60-100 mL / L.

[0018] The present invention provides a copper-containing plating solution, comprising: copper sulfate pentahydrate, sodium hypophosphite, glyoxylic acid, tetrasodium ethylenediaminetetraacetate, sodium citrate and deionized water. The copper-containing plating solution of the present invention realizes copper plating by using a double-reducing agent and double-complexing agent system; glyoxylic acid, as a secondary reducing agent, has strong reducibility and can quickly provide electrons at the initial stage of the reaction, enabling copper ions to quickly nucleate on the surface of the copper substrate to be plated, laying a foundation for the subsequent growth of the copper layer; sodium hypophosphite, as the main reducing agent, has stable reducing ability and can continuously reduce copper ions in the plating solution to copper atoms to realize the continuous growth of the copper layer; under the combined action of the main reducing agent and the secondary reducing agent, it is beneficial to obtain a dense and complete copper layer; tetrasodium ethylenediaminetetraacetate, as the main complexing agent, forms a complex with copper ions with high stability and can slowly release copper ions, enabling the copper ions to deposit on the substrate surface uniformly and orderly; sodium citrate, as the secondary complexing agent, can adjust the discharge potential and further optimize the deposition process of copper ions; under the combined action of the double complexing agents, copper ions form a stable complex, preventing copper ions from prematurely forming copper atoms and forming precipitates, avoiding ineffective deposition on the substrate surface, thereby realizing dense coating of the copper substrate to be plated and effectively improving the copper plating effect. The results of the examples show that the copper-containing plating solution provided by the present invention can form a densely coated copper layer on the surface of graphene. Description of the Drawings

[0019] Figure 1 SEM image of graphene with copper plating on the surface obtained in Example 2 at a magnification of 6500 times;

[0020] Figure 2 SEM image of graphene with copper plating on the surface obtained in Example 2 at a magnification of 20000 times;

[0021] Figure 3 Elemental analysis diagram of graphene with copper plating on the surface obtained in Example 2;

[0022] Figure 4 XRD diagram of graphene with copper plating on the surface obtained in Example 2;

[0023] Figure 5 SEM image of graphene with copper plating on the surface obtained in Comparative Example 2 at a magnification of 3000 times;

[0024] Figure 6 SEM image of graphene with copper plating on the surface obtained in Comparative Example 2 at a magnification of 3000 times;

[0025] Figure 7 Elemental analysis diagram of graphene with copper plating on the surface obtained in Comparative Example 2;

[0026] Figure 8 XRD diagram of graphene with copper plating on the surface obtained in Comparative Example 2. Detailed Embodiments

[0027] The present invention provides a copper-containing plating solution, comprising: copper sulfate pentahydrate, sodium hypophosphite, glyoxylic acid, tetrasodium ethylenediaminetetraacetate, sodium citrate and deionized water.

[0028] As an embodiment of the present invention, the concentration of copper sulfate pentahydrate in the copper-containing plating solution can be 7.5 - 20 g / L, or can be 10 - 18 g / L, or can also be 12 - 15 g / L. In the present invention, by limiting the concentration of copper sulfate pentahydrate, the concentration of copper ions in the copper-containing plating solution is controlled, further improving the copper plating effect.

[0029] As an embodiment of the present invention, the sodium hypophosphite in the copper-containing plating solution can be sodium hypophosphite or potassium hypophosphite; the concentration of the sodium hypophosphite can be 30 - 40 g / L, or can be 32 - 38 g / L, or can also be 35 - 36 g / L. In the present invention, by limiting the type and concentration of the sodium hypophosphite, the continuous reduction of copper ions in the copper-containing plating solution is realized, which is beneficial to the continuous growth of the copper layer, further improving the copper plating effect and facilitating the formation of a dense copper layer.

[0030] As an embodiment of the present invention, the concentration of glyoxylic acid in the copper-containing plating solution can be 5.25 - 25 mL / L, or can be 10 - 23 mL / L, or can also be 15 - 20 mL / L. In the present invention, by limiting the concentration of glyoxylic acid, a sufficient amount of electrons is rapidly provided at the initial stage of the reaction, which is beneficial to the rapid nucleation of copper ions on the surface of the copper substrate to be plated, further improving the copper plating effect.

[0031] As an embodiment of the present invention, the concentration of tetrasodium ethylenediaminetetraacetate in the copper-containing plating solution can be 15 - 30 g / L, or can be 18 - 25 g / L, or can also be 20 - 22 g / L. In the present invention, by limiting the concentration of tetrasodium ethylenediaminetetraacetate, the stability of the complex formed between the complexing agent and copper ions is improved, realizing the slow release of copper ions, which is beneficial to the uniform and orderly deposition of copper ions on the surface of the substrate, further improving the copper plating effect.

[0032] As an embodiment of the present invention, the concentration of sodium citrate in the copper-containing plating solution can be 25 - 75 g / L, or can be 30 - 65 g / L, or can also be 40 - 50 g / L. In the present invention, by limiting the concentration of sodium citrate, the discharge potential can be effectively adjusted, further optimizing the deposition process of copper ions and further improving the copper plating effect.

[0033] The copper-containing plating solution provided by the present invention is a double-reducing agent and double-complexing agent system, providing a good reduction environment for copper ions both at the initial stage and during the reaction, which is beneficial to the reduction and attachment of copper ions, effectively improving the copper plating effect.

[0034] The present invention does not have any special limitation on the preparation method of the copper-containing plating solution. It is only necessary to mix each component by an operation well-known to those skilled in the art to obtain a uniform solution.

[0035] The present invention also provides a method for copper plating on the surface of graphene, which includes the following steps:

[0036] (1) Pretreat the graphene to obtain activated graphene;

[0037] (2) Mix the activated graphene obtained in the step (1) with the copper-containing plating solution described in the above technical solution and then perform copper plating; the temperature of the copper plating is 30-60°C.

[0038] The present invention pretreats the graphene to obtain activated graphene.

[0039] As an embodiment of the present invention, the graphene can be physically-produced few-layer graphene; the number of graphene sheets can be 3-5 layers, or can be 4 layers; the sheet diameter of the graphene can be 10-15 μm, or can be 11-14 μm, or can also be 12-13 μm. In the present invention, by limiting the type of graphene, the surface state of graphene is effectively controlled, and the copper plating effect is further improved.

[0040] As an embodiment of the present invention, the pretreatment can include dispersion treatment, degreasing treatment, roughening treatment, sensitization treatment, and activation treatment performed in sequence.

[0041] As an embodiment of the present invention, the dispersion treatment can be to mix the graphene, a dispersant, and ethanol to obtain a suspension.

[0042] The present invention does not have any special limitation on the type of the dispersant, as long as it can disperse the graphene evenly. In the embodiments of the present invention, the dispersant can specifically be sodium dodecylbenzenesulfonate.

[0043] As an embodiment of the present invention, the mass of the dispersant can be 5-10% of the mass of the graphene, or can be 6-9%, or can also be 7-8%. In the present invention, by limiting the dosage of the dispersant, the full dispersion of the graphene matrix can be achieved, which is beneficial to the subsequent surface treatment of graphene and further realizes dense copper plating.

[0044] The present invention does not have any special limitation on the dosage of the ethanol, as long as it can fully disperse the graphene.

[0045] As an embodiment of the present invention, ultrasonic treatment can be performed when the graphene, dispersant, and ethanol are mixed; the power of the ultrasonic treatment can be 240 - 300 W, or 250 - 280 W, or 260 - 270 W; the time of the ultrasonic treatment can be 30 - 60 min, or 40 - 55 min, or 45 - 50 min. In the present invention, by defining the process parameters of the ultrasonic treatment, the dispersion effect of graphene is improved, and the copper plating effect is further improved.

[0046] As an embodiment of the present invention, the degreasing treatment can be to filter the suspension obtained by the dispersion treatment and then mix it with concentrated hydrochloric acid to obtain degreased graphene.

[0047] The present invention has no special limitation on the operation of the suction filtration, and the operation of suction filtration commonly used by those skilled in the art can be adopted.

[0048] As an embodiment of the present invention, the mass concentration of the concentrated hydrochloric acid can be 36 - 38%, or 37 - 37.5%. In the present invention, concentrated hydrochloric acid is used to degrease the surface of graphene to avoid the influence of impurities on the surface of graphene on subsequent operations; by defining the concentration of concentrated hydrochloric acid, the degreasing effect can be effectively controlled, and while fully degreasing, the damage to the graphene structure can be avoided.

[0049] As an embodiment of the present invention, the mass ratio of the graphene to the volume of the concentrated hydrochloric acid can be 1 g : (1 - 1.5) L, or 1 g : (1.1 - 1.4) L, or 1 g : (1.2 - 1.3) L. In the present invention, by defining the dosage of concentrated hydrochloric acid, the full contact between concentrated hydrochloric acid and graphene is achieved, and the complete degreasing of graphene is realized, laying a foundation for subsequent treatment.

[0050] As an embodiment of the present invention, ultrasonic treatment can be performed when the suspension is mixed with concentrated hydrochloric acid; the power and time of the ultrasonic treatment are the same as those of the above ultrasonic treatment, and will not be elaborated here.

[0051] As an embodiment of the present invention, after the degreasing treatment, the graphene can be washed with deionized water until neutral to obtain degreased graphene. In the present invention, by washing the graphene with deionized water, the influence of concentrated hydrochloric acid used for degreasing on subsequent operations is avoided.

[0052] As an embodiment of the present invention, the roughening treatment can be to mix the degreased graphene with a sodium hydroxide solution to obtain roughened graphene.

[0053] As an embodiment of the present invention, the concentration of the sodium hydroxide solution can be 100-150 g / L, or 110-140 g / L, or 120-130 g / L. In the present invention, by limiting the concentration of the sodium hydroxide solution, the amount of sodium hydroxide in the reaction system is controlled to ensure that while sufficiently roughening the surface of graphene, the structure of graphene is not damaged.

[0054] As an embodiment of the present invention, the mass ratio of the graphene to the volume of the sodium hydroxide solution can be 1 g:(1-1.5) L, or 1 g:(1.1-1.4) L, or 1 g:(1.2-1.3) L. In the present invention, by limiting the amount of the sodium hydroxide solution, the roughening of the graphene surface by sodium hydroxide is fully realized, the surface roughness of graphene is increased, and a foundation is laid for subsequent treatment.

[0055] As an embodiment of the present invention, ultrasonic treatment can be carried out when the degreased graphene is mixed with the sodium hydroxide solution; the power and time of the ultrasonic treatment are the same as those of the above ultrasonic treatment, and will not be elaborated here.

[0056] As an embodiment of the present invention, after the roughening treatment, graphene can be washed with deionized water until neutral to obtain roughened graphene.

[0057] As an embodiment of the present invention, the sensitization treatment can be carried out by mixing the roughened graphene with a sensitizer to obtain sensitized graphene.

[0058] As an embodiment of the present invention, the sensitizer can be an aqueous solution of stannous chloride and hydrogen chloride; the concentration of stannous chloride in the sensitizer can be 8-12 g / L, or 8.5-11 g / L, or 9-10 g / L; the concentration of hydrogen chloride in the sensitizer can be 60-100 mL / L, or 70-95 mL / L, or 80-90 mL / L. In the present invention, by limiting the concentrations of the two components in the sensitizer, the function of the sensitizer is realized, and the copper plating effect is further improved.

[0059] As an embodiment of the present invention, the mass ratio of the graphene to the volume of the sensitizer can be 1 g:(1-1.5) L, or 1 g:(1.1-1.4) L, or 1 g:(1.2-1.3) L. In the present invention, the sensitization treatment of graphene can form a liquid film of stannous chloride with a reduction effect on the surface of graphene; by limiting the amount of the sensitizer, the full sensitization of graphene is realized, and the copper plating effect is further improved.

[0060] As an embodiment of the present invention, ultrasonic treatment can be carried out when the roughened graphene is mixed with the sensitizer; the power and time of the ultrasonic treatment are the same as those of the above ultrasonic treatment, and will not be elaborated here.

[0061] As an embodiment of the present invention, after the sensitization treatment, deionized water can be used to wash the graphene until it is neutral to obtain sensitized graphene.

[0062] As an embodiment of the present invention, the activation treatment can be to mix the sensitized graphene with an activator to obtain activated graphene.

[0063] As an embodiment of the present invention, the activator can be an aqueous solution of palladium chloride and hydrogen chloride; the concentration of palladium chloride in the activator can be 0.8 - 1.2 g / L, or 0.85 - 1.1 g / L, or 0.9 - 1.0 g / L; the concentration of hydrogen chloride in the activator can be 60 - 100 mL / L, or 70 - 95 mL / L, or 80 - 90 mL / L. In the present invention, by limiting the concentrations of the two components in the activator, the performance of concentrated hydrochloric acid is fully exerted, and the copper plating effect is further improved.

[0064] As an embodiment of the present invention, the ratio of the mass of the sensitized graphene to the volume of the activator can be 1 g : (1 - 1.5) L, or 1 g : (1.1 - 1.4) L, or 1 g : (1.2 - 1.3) L. In the present invention, the activator is used to contact the sensitized graphene, and the palladium ions in the activator are reduced and deposited on the surface of the graphene to form activation centers, so that the copper atoms obtained by subsequent reduction are deposited and grown at the active centers, which is beneficial to subsequent copper plating; by limiting the amount of the activator, the graphene can be fully activated, and the copper plating effect is further improved.

[0065] As an embodiment of the present invention, ultrasonic treatment can be carried out when the sensitized graphene is mixed with the activator; the power and time of the ultrasonic treatment are the same as those of the above ultrasonic treatment, and will not be elaborated here.

[0066] As an embodiment of the present invention, after the activation treatment, deionized water can be used to wash the graphene until it is neutral to obtain activated graphene.

[0067] After obtaining the activated graphene, the present invention mixes the activated graphene with the copper-containing plating solution described in the above technical solution and then conducts copper plating.

[0068] As an embodiment of the present invention, the mass ratio of the activated graphene to the copper-containing plating solution can be 1g:(0.5-1.5)mL, 1g:(0.8-1.2)mL, or 1g:(1.0-1.1)mL. In the present invention, by limiting the amount of the copper-containing plating solution, the activated graphene and the copper-containing plating solution are fully contacted and reacted, and the copper ions are reduced to obtain copper element, so that the generated copper element is too little to fully cover the graphene surface, and the copper plating effect is further improved.

[0069] As an embodiment of the present invention, the copper plating temperature is 30-60°C, 40-55°C, or 45-50°C; the copper plating heating method can be water bath heating; the copper plating time can be 60-90 minutes, 70-80 minutes, or 75-78 minutes. In the present invention, copper ions will be reduced to nucleate at the active center during the copper plating process, and a dense copper film will be grown; by limiting the process parameters of the copper plating process, the copper plating process can be carried out under suitable conditions, further improving the copper plating effect.

[0070] As an embodiment of the present invention, the pH of the copper-containing plating solution before copper plating can be adjusted to 12-14, or 13; the pH of the copper-containing plating solution can be adjusted using sodium hydroxide. In the present invention, by limiting the pH of copper-containing plating, the interaction between the copper-containing plating solution and graphene is promoted, and the copper plating effect is further improved.

[0071] As an embodiment of the present invention, the copper plating can be stirred at the same time; the stirring rate can be 500-1000rpm / min, 600-900rpm / min, or 700-800rpm / min. In the present invention, by limiting the stirring rate, the effective components in the copper-containing plating solution are fully contacted and reacted with the graphene, further improving the copper plating effect.

[0072] The preparation method provided by the present invention pre-treats graphene, adjusts the graphene surface to a state suitable for copper plating, and controls the process parameters of the copper plating reaction to achieve sufficient contact reaction between the graphene and the copper-containing plating solution, effectively improves the copper plating effect, and forms a dense copper film on the graphene surface.

[0073] In order to further illustrate the present invention, the copper-containing plating solution and the graphene surface copper plating method provided by the present invention are described in detail below in combination with the embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0074] Example 1

[0075] A copper-containing plating solution is an aqueous solution of copper sulfate pentahydrate, sodium hypophosphite, glyoxylic acid, tetrasodium ethylenediaminetetraacetate and sodium citrate;

[0076] In the copper-containing plating solution, the concentration of copper sulfate pentahydrate is 10 g / L, the concentration of sodium hypophosphite is 40 g / L, the concentration of glyoxylic acid is 10 mL / L, the concentration of sodium ethylenediaminetetraacetate is 20 g / L, and the concentration of sodium citrate is 50 g / L.

[0077] Example 2

[0078] A method for copper plating on the surface of graphene:

[0079] (1) 0.1 g of graphene with a sheet diameter of 10 μm and 3 - 5 layers of sheets, sodium dodecylbenzenesulfonate (10% of the mass of graphene) and ethanol are mixed and dispersed at 240 W for 30 min to obtain a suspension; the suspension and 0.1 L of concentrated hydrochloric acid with a mass concentration of 36 - 38% (the mass ratio of graphene to the volume of concentrated hydrochloric acid is 1 g:1 L) are ultrasonically mixed at 240 W for 30 min for degreasing treatment. After the degreasing treatment, the graphene is washed with deionized water until neutral to obtain degreased graphene; the degreased graphene and 0.1 L of sodium hydroxide with a concentration of 100 g / L (the mass ratio of graphene to the volume of sodium hydroxide is 1 g:1 L) are ultrasonically mixed at 240 W for 30 min for roughening treatment. After the roughening treatment, the degreased graphene is washed with deionized water until neutral to obtain roughened graphene; the roughened graphene and 0.1 L of sensitizer (the mass ratio of graphene to the volume of sensitizer is 1 g:1 L) are ultrasonically mixed at 240 W for 30 min for sensitization treatment. After the sensitization treatment, the roughened graphene is washed with deionized water until neutral to obtain sensitized graphene; among them, the sensitizer is a mixed solution of 10 g / L of stannous chloride and 80 mL / L of concentrated hydrochloric acid; the sensitized graphene and 0.1 L of activator (the mass ratio of graphene to the volume of activator is 1 g:1 L) are ultrasonically mixed at 240 W for 30 min for activation treatment. After the activation treatment, the sensitized graphene is washed with deionized water until neutral to obtain activated graphene; among them, the activator is a mixed solution of 1 g / L of palladium chloride and 80 mL / L of concentrated hydrochloric acid;

[0080] (2) The activated graphene obtained in step (1) and the copper-containing plating solution obtained in Example 1 (the mass ratio of graphene to the volume of the copper-containing plating solution is 1 g:0.1 L) are mixed and then copper plating is carried out at 60 °C and 800 rpm / min for 60 min; among them, before the copper plating, sodium hydroxide is used to adjust the pH value of the copper-containing plating solution to make the pH of the copper-containing plating solution 13.

[0081] The copper-plated graphene material obtained in Example 2 is detected by a scanning electron microscope at magnifications of 6500 and 20000 respectively, and the obtained morphological characterization results are respectively as Figures 1-2 shown, and the obtained elemental analysis results are as Figure 3As shown; the copper-plated graphene material obtained in Example 4 was detected using an X-ray diffractometer, and the results obtained are as Figure 4 shown. As can be seen from Figures 1-4 , when the graphene was coated with the copper-containing plating solution of Example 2, a dense copper film was formed on the surface of the graphene; at the same time, as can be seen from Figure 3 , when the copper-containing plating solution of Example 2 was used for coating, the elemental distribution of the obtained coating was concentrated, further indicating that a dense copper film was obtained; and it can be seen from Figure 4 that the element of the dense copper film is elemental copper.

[0082] Comparative Example 1

[0083] A copper-containing plating solution is an aqueous solution of copper sulfate pentahydrate, sodium hypophosphite, glyoxylic acid, tetrasodium ethylenediaminetetraacetate and sodium citrate;

[0084] In the copper-containing plating solution, the concentration of copper sulfate pentahydrate is 5 g / L, the concentration of sodium hypophosphite is 25 g / L, the concentration of glyoxylic acid is 5 mL / L, the concentration of tetrasodium ethylenediaminetetraacetate is 20 g / L, and the concentration of sodium citrate is 75 g / L.

[0085] Comparative Example 2

[0086] The difference between Comparative Example 2 and Example 2 is only that the copper-containing plating solution is the copper-containing plating solution of Comparative Example 1, and the others are the same as Example 2.

[0087] The copper-plated graphene material obtained in Comparative Example 2 was detected using a scanning electron microscope at a magnification of 3000 times, and the morphological characterization results obtained are as Figures 5-6 shown, and the obtained elemental analysis results are as Figure 7 shown; the copper-plated graphene material obtained in Comparative Example 2 was detected using an X-ray diffractometer, and the results obtained are as Figure 8 shown. As can be seen from Figures 5-8 , when the graphene was coated with the copper-containing plating solution of Comparative Example 1, copper oxide was formed on the surface of the graphene, and the surface was coated mainly with Cu 2 O, because a side reaction occurred, and the specific reaction formula is: 2Cu 2+ +2CHO - +6OH - →Cu 2 O+2HCOO - +3H 2 O; at the same time, as can be seen from Figure 7 , the elemental distribution is dispersed, and the graphene is not densely coated; and it can be seen from Figure 8 that there is no elemental copper on the surface of the graphene.

[0088] In summary, the copper-containing coating provided by the present invention can achieve dense coating on the surface of graphene.

[0089] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A copper-containing plating solution, characterized in that include: Cupric sulfate pentahydrate, hypophosphite, glyoxylic acid, tetrasodium EDTA, sodium citrate, and deionized water.

2. The copper-containing plating solution according to claim 1, characterized in that The concentration of copper sulfate pentahydrate in the copper-containing plating solution is 7.5-20 g / L, the concentration of hypophosphite is 30-40 g / L, the concentration of glyoxylic acid is 5.25-25 mL / L, the concentration of tetrasodium ethylenediaminetetraacetate is 15-30 g / L, and the concentration of sodium citrate is 25-70 g / L.

3. A method for copper plating on a graphene surface, characterized in that: The following steps are involved: (1) pre-treating graphene to obtain activated graphene; (2) The activated graphene obtained in step (1) is mixed with the copper-containing plating solution according to claim 1 or 2 and then copper-plated; the copper plating temperature is 30 to 60° C.

4. The method for copper plating on the surface of graphene according to claim 3, characterized in that: In the step (2), the volume ratio of the mass of activated graphene to the copper-containing plating solution is 1 g: (0.5-1.5) L.

5. The method for copper plating on the surface of graphene according to claim 3, characterized in that: In the step (2), the pH of the copper-containing plating solution is adjusted to 12-14 before copper plating.

6. The method for copper plating on a graphene surface according to claim 3, characterized in that: The copper plating time in step (2) is 60 to 90 minutes.

7. The method for copper plating on a graphene surface according to claim 3, characterized in that: The pretreatment in step (1) includes dispersion treatment, oil removal treatment, roughening treatment, sensitization treatment and activation treatment performed in sequence.

8. The method for copper plating on the surface of graphene according to claim 7, characterized in that: The roughening agent used for the roughening treatment is a sodium hydroxide solution.

9. The method for copper plating on a graphene surface according to claim 7, characterized in that: The sensitizer used for sensitization treatment is an aqueous solution of stannous chloride and hydrogen chloride; the concentration of stannous chloride in the sensitizer is 8-12 g / L; the concentration of hydrogen chloride in the sensitizer is 60-100 mL / L.

10. The method for copper plating on the surface of graphene according to claim 7, characterized in that: The activating agent for activation treatment is an aqueous solution of palladium chloride and hydrogen chloride; the concentration of palladium chloride in the activating agent is 0.8-1.2 g / L; the concentration of hydrogen chloride in the activating agent is 60-100 mL / L.

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