Graphene and carbon nanotube doped silver plating solution and preparation method thereof

Abstract

The application belongs to the technical field of silver plating, and particularly relates to a graphene and carbon nanotube doped silver plating solution and a preparation method thereof. The graphene and carbon nanotube doped silver plating solution comprises silver cyanide 20-50 g / L, potassium cyanide 80-150 g / L, potassium carbonate 15-30 g / L, graphene and carbon nanotube composite powder 70-90 g / L, electroplating additives 5-12 g / L, and the balance of water. The graphene and carbon nanotube composite powder comprises graphene and carbon nanotube with a content of 40-65% and a ratio of 1:1-1.5:1, 15-25% of a dispersing agent, and the balance of an organic solvent. The electroplating additives comprise 20-35% of a surfactant, 8-17% of a dispersing agent, 5-10% of a stabilizer, and the balance of water. The graphene and carbon nanotube doped silver plating solution has obvious enhancement effects on the wear resistance, electrical conductivity, and hardness of a silver plating layer.

Description

Technical Field

[0001] This invention belongs to the field of silver plating technology, and particularly relates to a graphene and carbon nanotube doped silver plating solution and its preparation method. Background Technology

[0002] Silver plating is a process in which metal cations are deposited on the surface of a workpiece. The plating solution directly affects the final appearance of the workpiece. With the development of technology, the requirements for the conductivity, wear resistance and hardness of the workpiece are getting higher and higher, especially in the aerospace and communication terminal industries where the demand for such products is increasing.

[0003] Currently, silver plating solutions mainly consist of two systems: ordinary cyanide silver plating and cyanide-free silver plating. However, with changing market demands, achieving better conductivity, stronger wear resistance, and higher hardness using only ordinary silver plating solutions is difficult. Theoretical research shows that adding an appropriate amount of carbon to the plating solution can enhance the thermal and electrical conductivity of the coating, and also significantly improve the lubrication between the coating and other contact surfaces, thereby improving the wear resistance of the coating. Currently, commonly used carbon materials in various studies include graphite, graphene, and carbon nanotubes. Among them, graphite has excellent friction-reducing and self-lubricating properties, but due to its internal crystal structure and chemical bonding, the conductivity and mechanical strength of the silver coating obtained after adding it to the silver plating solution will be greatly reduced. In contrast, graphene, being a single-layer honeycomb two-dimensional material, has excellent electrical, thermal, and mechanical properties. The hollow tubular structure of carbon nanotubes also provides excellent electrical, thermal, and mechanical properties. Electroplating coatings obtained by mixing these two materials into the silver plating solution will have better electrical conductivity, thermal conductivity, and wear resistance. However, due to the unique hollow structure of carbon nanotubes, adding carbon nanotubes alone to the silver plating solution for electroplating will result in poor adhesion of the coating. In subsequent product transportation and processing, when exposed to high temperature, high humidity, and high acid and alkali environments, peeling, oxidation and other adverse phenomena are likely to occur, ultimately affecting product quality and performance.

[0004] Based on this situation, the present invention proposes a method for preparing and applying a graphene and carbon nanotube-doped silver plating solution. Summary of the Invention

[0005] The purpose of this invention is to provide a graphene and carbon nanotube doped silver electroplating solution and its preparation method, aiming to solve the technical problem that the conductivity, wear resistance and hardness of products made from existing silver electroplating solutions need to be improved.

[0006] To achieve the above objectives, the graphene and carbon nanotube-doped silver plating solution provided in this embodiment of the invention comprises 20-50 g / L silver cyanide, 80-150 g / L potassium cyanide, 15-30 g / L potassium carbonate, 70-90 g / L carbon nanotube and graphene powder, 5-12 g / L electroplating additive, and the balance being water; wherein the carbon nanotube and graphene powder comprises 40-65% graphene and carbon nanotube in a ratio of 1:1-1.5:1, 15-25% dispersant, and the balance being organic solvent; and the electroplating additive comprises 20-35% surfactant, 8-17% dispersant, 5-10% stabilizer, and the balance being water.

[0007] As a further aspect of the present invention, the graphene is a single-layer graphene with a purity of 98% or higher.

[0008] As a further embodiment of the present invention, the carbon nanotube is a multi-walled carbon nanotube with a diameter of 50-100 nm and a length of 1-200 μm.

[0009] As a further embodiment of the present invention, the dispersant is one or more mixtures of polyvinyl alcohol (PVA), polyacrylate (TPO), or triethylhexyl phosphate (TP).

[0010] As a further embodiment of the present invention, the organic solvent is one of N,N-dimethylformamide (DMF), tetrahydrofuran (THF), or ethyl acetate (EA).

[0011] As a further embodiment of the present invention, the surfactant is one or more of polyethylene glycol-400 (PEG), Triton X-114 (TX), or nonylphenol polyoxyethylene ether (OP).

[0012] As a further embodiment of the present invention, the stabilizer is one or more of glycerol (GL), carboxymethyl cellulose (CMC), or sodium stearate (SS).

[0013] As a further aspect of the present invention, the water in the electroplating additive is deionized water, distilled water, or double-distilled water.

[0014] As part of the same inventive concept as this invention, this application also provides a method for preparing a graphene and carbon nanotube-doped silver plating solution, comprising the following steps:

[0015] (I) Preparation of carbon nanotube and graphene powders:

[0016] S1: Weigh 40-65% of graphene and carbon nanotubes in a ratio of 1:1-1.5:1 and put them into a stirrer. Add 15-25% of dispersant and the remainder of organic solvent. Stir for 4-6 hours to dissolve the solids to obtain mixture A.

[0017] S2: Spread the mixture A obtained in S1 evenly in a tray, place it in an oven at 70-80℃ and bake for 2-3 hours until completely dried to obtain carbon nanotubes and graphene powder.

[0018] (II) Preparation of electroplating additives:

[0019] S3: Add 20-35% surfactant to 20% water and stir until homogeneous to obtain mixture B;

[0020] S4: Add 8-17% dispersant and 5-10% stabilizer to mixture B of S3, control the temperature at 30-50℃, and stir for 1 hour to obtain mixture C;

[0021] S5: Add the remaining water to mixture B of S4, maintain the temperature and stir for 2-3 hours to obtain the electroplating additive.

[0022] (III) Preparation of graphene and carbon nanotube-doped silver plating solution:

[0023] S6: Add 2 / 3 volume of pure water to the electroplating tank;

[0024] S7: Add 80-150 g / L potassium cyanide to the pure water in S6, heat to 40 degrees and stir to dissolve it;

[0025] S8: Add 20-50 g / L silver cyanide to the potassium cyanide solution obtained in S6 and dissolve to obtain mixture D;

[0026] S9: Add 15-30 g / L potassium carbonate to mixture D obtained in S7 and dissolve to obtain mixture E;

[0027] S10: Add 70-90 g / L of carbon nanotubes and graphene powder and 5-12 g / L of electroplating additives to mixture E obtained in S9, and stir thoroughly to dissolve to obtain mixture F;

[0028] S11: Add the remaining water to the standard volume of 200L, and cool it to 16-25℃ to obtain the desired graphene and carbon nanotube doped silver plating solution.

[0029] The graphene and carbon nanotube-doped silver plating solution provided in this embodiment of the invention has at least one of the following technical effects:

[0030] First, the graphene and carbon nanotube-doped silver plating solution prepared by the technical solution of this invention is most notably characterized by the presence of carbon nanotubes and graphene powder, which significantly enhances the wear resistance, conductivity, and hardness of the silver plating layer. Since graphene has a two-dimensional structure and carbon nanotubes have a three-dimensional structure, both possess extremely large specific surface areas. Adding carbon nanotubes and graphene powder to the silver plating solution greatly increases the dispersion, uniformity, and interfacial bonding of silver ions on the substrate surface. Furthermore, due to the unique physical and chemical properties of graphene and carbon nanotubes, in addition to improving the oxidation resistance of the silver plating layer, it also significantly increases its wear resistance, conductivity, and hardness. The resulting product exhibits superior performance compared to products obtained through ordinary silver plating processes, better meeting the specific needs of customers.

[0031] Secondly, the electroplating additives prepared by the technical solution of the present invention contain dispersants and stabilizers, which are all common organic or inorganic substances on the market. They have good stability and are all non-toxic and harmless substances. Adding them to the silver plating solution can not only increase the dispersibility of carbon nanotubes and graphene powder in the silver plating solution, but also increase the dispersibility and stability of various components in the silver plating solution, so that the silver layer on the surface of the final product is deposited more evenly and smoothly.

[0032] Third, the graphene and carbon nanotube-doped silver plating solution prepared by the technical method of this invention has a faster silver ion deposition rate, a wider range of operable current densities, and a more stable pH of the plating solution. Compared with products prepared by the traditional cyanide silver plating system, the silver plating products prepared using this silver plating solution have stronger silver layer adhesion, smoother surface, better wear resistance, better conductivity, and higher hardness, thus improving the overall quality of the silver plating products.

[0033] Fourth, the graphene and carbon nanotube doped silver plating solution (YCYY-35) prepared by the technical solution of the present invention and the products plated by commercially available traditional silver plating solutions X, Y, and Z, respectively, are all applied to the same workpiece surface using their optimal process parameters. After the electroplating is completed, the coatings applied by the graphene and carbon nanotube doped silver plating solution prepared by the technical solution of the present invention have significantly improved conductivity, wear resistance, and hardness compared to the coatings applied by traditional silver plating solutions.

[0034] Fifth, the graphene and carbon nanotube-doped silver plating solution prepared by the technical solution of this invention has a simple preparation process and can be used to electroplate silver on substrates of various shapes, specifications, and sizes. Its application is simple, convenient, and widely applicable. Furthermore, its production and use processes do not require high temperatures, resulting in low energy consumption and easy large-scale production and application, thus offering excellent economic benefits. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 The following is a comparison of the scanning electron microscope (SEM) micrographs of the products after plating with graphene and carbon nanotube doped silver electroplating solution prepared according to the technical solution of the present invention and commonly available silver electroplating solutions X, Y, and Z on the surface of the workpiece, while keeping their electroplating parameters consistent. From left to right and from top to bottom, they are X, Y, Z, and YCYY-35.

[0037] Figure 2 In Example 1, the hardness test indentation images of the products after plating were compared using the graphene and carbon nanotube doped silver plating solution prepared according to the technical solution of the present invention and the commonly available silver plating solutions X, Y, and Z, while keeping their plating parameters consistent. From left to right and from top to bottom, they are X, Y, Z, and YCYY-35.

[0038] Figure 3 The image shows a comparison of wear resistance test traces of products after plating with graphene and carbon nanotube doped silver plating solution prepared according to the technical solution of the present invention and commonly available silver plating solutions X, Y, and Z on the workpiece surface, while keeping their plating parameters consistent. The traces are X, Y, Z, and YCYY-35 from left to right and top to bottom.

[0039] Figure 4 The table compares the results of partial optimization of the graphene and carbon nanotube doped silver plating solution (YCYY-35) prepared for the technical solution of this invention with those of the products plated by commercially available traditional silver plating solutions X, Y, and Z. All four systems were plated with silver layers on the same workpiece surface using their optimal process parameters. After the electroplating was completed, the conductivity (contact resistance), wear resistance (wear resistance cycle), and hardness (Vickers hardness) of the plating layers were tested. Detailed Implementation

[0040] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0041] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0043] In the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0044] Example 1:

[0045] In one embodiment of the present invention, a graphene and carbon nanotube-doped silver plating solution is provided, comprising 20-50 g / L silver cyanide, 80-150 g / L potassium cyanide, 15-30 g / L potassium carbonate, 70-90 g / L carbon nanotube and graphene powder, 5-12 g / L electroplating additive, and the balance being water; wherein the carbon nanotube and graphene powder comprises 40-65% graphene and carbon nanotube in a ratio of 1:1-1.5:1, 15-25% dispersant, and the balance being organic solvent, and the electroplating additive comprises 20-35% surfactant, 8-17% dispersant, 5-10% stabilizer, and the balance being water.

[0046] In another embodiment of the present invention, the graphene is a single-layer graphene with a purity of 98% or higher.

[0047] In another embodiment of the present invention, the carbon nanotubes are multi-walled carbon nanotubes with a diameter of 50-100 nm and a length of 1-200 μm.

[0048] In another embodiment of the invention, the dispersant is one or a mixture of polyvinyl alcohol (PVA), polyacrylate (TPO), or triethylhexyl phosphate (TP).

[0049] In another embodiment of the invention, the organic solvent is one of N,N-dimethylformamide (DMF), tetrahydrofuran (THF), or ethyl acetate (EA).

[0050] In another embodiment of the invention, the surfactant is one or more of polyethylene glycol-400 (PEG), Triton X-114 (TX), or nonylphenol polyoxyethylene ether (OP).

[0051] In another embodiment of the invention, the stabilizer is one or more of glycerol (GL), carboxymethyl cellulose (CMC), or sodium stearate (SS).

[0052] In another embodiment of the present invention, the water in the electroplating additive is deionized water, distilled water, or double-distilled water.

[0053] In this embodiment of the invention, the preparation process of the graphene and carbon nanotube-doped silver plating solution is as follows:

[0054] (I) Preparation of carbon nanotube and graphene powders:

[0055] S1: Weigh 40% of graphene and carbon nanotubes in a 1:1 ratio and put them into a stirrer. Add 15% PVA and 45% DMF and stir for 4 hours to dissolve the solids to obtain mixture A.

[0056] S2: Spread the mixture A obtained in S1 evenly in a tray, place it in an oven at 70°C and bake for 2 hours until completely dried to obtain carbon nanotubes and graphene powder.

[0057] (II) Preparation of electroplating additives:

[0058] S3: Add 20% PEG to 20% water and stir until homogeneous to obtain mixture B;

[0059] S4: Add 8% PVA and 5% GL to mixture B of S3, control the temperature at 30℃, and stir for 1 hour to obtain mixture C;

[0060] S5: Add 47% water to mixture B of S4, maintain the temperature and stir for 2 hours to obtain the electroplating additive.

[0061] (III) Preparation of graphene and carbon nanotube-doped silver plating solution:

[0062] S6: Add 2 / 3 volume of pure water to the electroplating tank;

[0063] S7: Add 80-150 g / L potassium cyanide to the pure water in S6, heat to 40 degrees and stir to dissolve it;

[0064] S8: Add 20-50 g / L silver cyanide to the potassium cyanide solution obtained in S6 and dissolve to obtain mixture D;

[0065] S9: Add 15-30 g / L potassium carbonate to mixture D obtained in S7 and dissolve to obtain mixture E;

[0066] S10: Add 70-90 g / L of carbon nanotubes and graphene powder and 5-12 g / L of electroplating additives to mixture E obtained in S9, and stir thoroughly to dissolve to obtain mixture F;

[0067] S11: Add the remaining water to the standard volume of 200L, and cool it to 16-25℃ to obtain the desired graphene and carbon nanotube doped silver plating solution.

[0068] The graphene and carbon nanotube-doped silver plating solution prepared in this invention is used to plate a silver layer on the surface of a pre-plated part. The process parameters to be controlled during electroplating are as follows: pH 12-14, operating temperature 16-25℃, silver ion content in the solution 20-50 g / L, and carbon nanotube and graphene powder content 70-90 g / L. No filtration of the plating solution is required during use; 15 g of carbon nanotube and graphene powder can be added for every 2 kg of silver plated. After electroplating, the conductivity (contact resistance), wear resistance cycle, and Vickers hardness of the product were tested and found to be 0.2 mΩ, 2000 cycles, and 228.5 HV, respectively.

[0069] Example 2: The specific preparation process of the graphene and carbon nanotube doped silver plating solution provided by the present invention is as follows:

[0070] (I) Preparation of carbon nanotube and graphene powders:

[0071] S1: Weigh 45% of graphene and carbon nanotubes in a ratio of 1.1:1 and put them into a stirrer. Add 17% TPO and 38% DMF and stir for 4 hours to dissolve the solids to obtain mixture A.

[0072] S2: Spread the mixture A obtained in S1 evenly in a tray, place it in an oven at 70°C and bake for 2 hours until completely dried to obtain carbon nanotubes and graphene powder.

[0073] (II) Preparation of electroplating additives:

[0074] S3: Add 23% TX to 20% water and stir until homogeneous to obtain mixture B;

[0075] S4: Add 10% TPO and 6% CMC to mixture B of S3, control the temperature at 35℃, and stir for 1 hour to obtain mixture C;

[0076] S5: Add 41% water to mixture B of S4, maintain the temperature and stir for 2 hours to obtain the electroplating additive.

[0077] (III) Preparation of graphene and carbon nanotube-doped silver plating solution:

[0078] S6: Add 2 / 3 volume of pure water to the electroplating tank;

[0079] S7: Add 80-150 g / L potassium cyanide to the pure water in S6, heat to 40 degrees and stir to dissolve it;

[0080] S8: Add 20-50 g / L silver cyanide to the potassium cyanide solution obtained in S6 and dissolve to obtain mixture D;

[0081] S9: Add 15-30 g / L potassium carbonate to mixture D obtained in S7 and dissolve to obtain mixture E;

[0082] S10: Add 70-90 g / L of carbon nanotubes and graphene powder and 5-12 g / L of electroplating additives to mixture E obtained in S9, and stir thoroughly to dissolve to obtain mixture F;

[0083] S11: Add the remaining water to the standard volume of 200L, and cool it to 16-25℃ to obtain the desired graphene and carbon nanotube doped silver plating solution.

[0084] The graphene and carbon nanotube-doped silver plating solution prepared in this invention is used to plate a silver layer on the surface of a pre-plated part. The process parameters to be controlled during electroplating are as follows: pH 12-14, operating temperature 16-25℃, silver ion content in the solution 20-50 g / L, and carbon nanotube and graphene powder content 70-90 g / L. No filtration of the plating solution is required during use; 15 g of carbon nanotube and graphene powder can be added for every 2 kg of silver plated. After electroplating, the conductivity (contact resistance), wear resistance cycle, and Vickers hardness of the product were tested and found to be 0.25 mΩ, 2100 cycles, and 254.2 HV, respectively.

[0085] Example 3: The specific preparation process of the graphene and carbon nanotube doped silver plating solution provided by the present invention is as follows:

[0086] (I) Preparation of carbon nanotube and graphene powders:

[0087] S1: Weigh 50% of graphene and carbon nanotubes in a ratio of 1.2:1 and put them into a stirrer. Add 19% TP and 31% THF and stir for 5 hours to dissolve the solids to obtain mixture A.

[0088] S2: Spread the mixture A obtained in S1 evenly in a tray, place it in an oven at 75°C and bake for 2.5 hours until completely dried to obtain carbon nanotubes and graphene powder.

[0089] (II) Preparation of electroplating additives:

[0090] S3: Add 26% OP to 20% water and stir until homogeneous to obtain mixture B;

[0091] S4: Add 12% TP and 7% SS to mixture B of S3, control the temperature at 40℃, and stir for 1 hour to obtain mixture C;

[0092] S5: Add 35% water to mixture B of S4, maintain the temperature, and stir for 2 hours to obtain the electroplating additive.

[0093] (III) Preparation of graphene and carbon nanotube-doped silver plating solution:

[0094] S6: Add 2 / 3 volume of pure water to the electroplating tank;

[0095] S7: Add 80-150 g / L potassium cyanide to the pure water in S6, heat to 40 degrees and stir to dissolve it;

[0096] S8: Add 20-50 g / L silver cyanide to the potassium cyanide solution obtained in S6 and dissolve to obtain mixture D;

[0097] S9: Add 15-30 g / L potassium carbonate to mixture D obtained in S7 and dissolve to obtain mixture E;

[0098] S10: Add 70-90 g / L of carbon nanotubes and graphene powder and 5-12 g / L of electroplating additives to mixture E obtained in S9, and stir thoroughly to dissolve to obtain mixture F;

[0099] S11: Add the remaining water to the standard volume of 200L, and cool it to 16-25℃ to obtain the desired graphene and carbon nanotube doped silver plating solution.

[0100] The graphene and carbon nanotube-doped silver plating solution prepared in this invention is used to plate a silver layer on the surface of a pre-plated part. The process parameters to be controlled during electroplating are as follows: pH 12-14, operating temperature 16-25℃, silver ion content in the solution 20-50 g / L, and carbon nanotube and graphene powder content 70-90 g / L. No filtration of the plating solution is required during use; 15 g of carbon nanotube and graphene powder can be added for every 2 kg of silver plated. After electroplating, the conductivity (contact resistance), wear resistance cycle, and Vickers hardness of the product were tested and found to be 0.1 mΩ, 2050 cycles, and 233.7 HV, respectively.

[0101] Example 4: The specific preparation process of the graphene and carbon nanotube doped silver plating solution provided by the present invention is as follows:

[0102] (I) Preparation of carbon nanotube and graphene powders:

[0103] S1: Weigh 55% of graphene and carbon nanotubes in a ratio of 1.3:1 and put them into a stirrer. Add 21% of a mixture of PVA and TPO and stir for 5 hours to dissolve the solids to obtain mixture A.

[0104] S2: Spread the mixture A obtained in S1 evenly in a tray, place it in an oven at 75°C and bake for 2.5 hours until completely dried to obtain carbon nanotubes and graphene powder.

[0105] (II) Preparation of electroplating additives:

[0106] S3: Add 29% of a mixture of PEG and OP to 20% water and stir until homogeneous to obtain mixture B;

[0107] S4: Add 14% of a mixture of PVA and TPO and 8% of a mixture of GL and SS to mixture B of S3, control the temperature at 40℃, and stir for 1 hour to obtain mixture C;

[0108] S5: Add 29% water to mixture B of S4, maintain the temperature and stir for 3 hours to obtain the electroplating additive.

[0109] (III) Preparation of graphene and carbon nanotube-doped silver plating solution:

[0110] S6: Add 2 / 3 volume of pure water to the electroplating tank;

[0111] S7: Add 80-150 g / L potassium cyanide to the pure water in S6, heat to 40 degrees and stir to dissolve it;

[0112] S8: Add 20-50 g / L silver cyanide to the potassium cyanide solution obtained in S6 and dissolve to obtain mixture D;

[0113] S9: Add 15-30 g / L potassium carbonate to mixture D obtained in S7 and dissolve to obtain mixture E;

[0114] S10: Add 70-90 g / L of carbon nanotubes and graphene powder and 5-12 g / L of electroplating additives to mixture E obtained in S9, and stir thoroughly to dissolve to obtain mixture F;

[0115] S11: Add the remaining water to the standard volume of 200L, and cool it to 16-25℃ to obtain the desired graphene and carbon nanotube doped silver plating solution.

[0116] The graphene and carbon nanotube-doped silver plating solution prepared in this invention is used to plate a silver layer on the surface of a pre-plated part. The process parameters to be controlled during electroplating are as follows: pH 12-14, operating temperature 16-25℃, silver ion content in the solution 20-50 g / L, and carbon nanotube and graphene powder content 70-90 g / L. No filtration of the plating solution is required during use; 15 g of carbon nanotube and graphene powder can be added for every 2 kg of silver plated. After electroplating, the conductivity (contact resistance), wear resistance cycle, and Vickers hardness of the product were tested and found to be 0.22 mΩ, 2250 cycles, and 282.5 HV, respectively.

[0117] Example 5: The specific preparation process of the graphene and carbon nanotube doped silver plating solution provided in this application is as follows:

[0118] (I) Preparation of carbon nanotube and graphene powders:

[0119] S1: Weigh 60% of graphene and carbon nanotubes in a ratio of 1.4:1 and put them into a stirrer. Add 23% of a mixture of TPO and TP and 17% of EA. Stir for 6 hours to dissolve the solids to obtain mixture A.

[0120] S2: Spread the mixture A obtained in S1 evenly in a tray, place it in an oven at 80°C for 3 hours, and bake until completely dry to obtain carbon nanotubes and graphene powder.

[0121] (II) Preparation of electroplating additives:

[0122] S3: Add 32% of the mixture of TX and OP to 20% water and stir until homogeneous to obtain mixture B;

[0123] S4: Add 16% of a mixture of TPO and TP, and 9% of a mixture of CMC and SS to mixture B of S3, control the temperature at 45℃, and stir for 1 hour to obtain mixture C;

[0124] S5: Add 23% water to mixture B of S4, maintain the temperature and stir for 3 hours to obtain the electroplating additive.

[0125] (III) Preparation of graphene and carbon nanotube-doped silver plating solution:

[0126] S6: Add 2 / 3 volume of pure water to the electroplating tank;

[0127] S7: Add 80-150 g / L potassium cyanide to the pure water in S6, heat to 40 degrees and stir to dissolve it;

[0128] S8: Add 20-50 g / L silver cyanide to the potassium cyanide solution obtained in S6 and dissolve to obtain mixture D;

[0129] S9: Add 15-30 g / L potassium carbonate to mixture D obtained in S7 and dissolve to obtain mixture E;

[0130] S10: Add 70-90 g / L of carbon nanotubes and graphene powder and 5-12 g / L of electroplating additives to mixture E obtained in S9, and stir thoroughly to dissolve to obtain mixture F;

[0131] S11: Add the remaining water to the standard volume of 200L, and cool it to 16-25℃ to obtain the desired graphene and carbon nanotube doped silver plating solution.

[0132] The graphene and carbon nanotube-doped silver plating solution prepared in this invention is used to plate a silver layer on the surface of a pre-plated part. The process parameters to be controlled during electroplating are as follows: pH 12-14, operating temperature 16-25℃, silver ion content in the solution 20-50 g / L, and carbon nanotube and graphene powder content 70-90 g / L. No filtration of the plating solution is required during use; 15 g of carbon nanotube and graphene powder can be added for every 2 kg of silver plated. After electroplating, the conductivity (contact resistance), wear resistance cycle, and Vickers hardness test results for the product are 0.3 mΩ, 1850 cycles, and 202.5 HV, respectively.

[0133] Example 6: The specific preparation process of the graphene and carbon nanotube doped silver plating solution provided in this application is as follows:

[0134] (I) Preparation of carbon nanotube and graphene powders:

[0135] S1: Weigh 65% of graphene and carbon nanotubes in a ratio of 1.5:1 and put them into a stirrer. Add 25% of a mixture of PVA and TP and 10% of EA. Stir for 6 hours to dissolve the solids to obtain mixture A.

[0136] S2: Spread the mixture A obtained in S1 evenly in a tray, place it in an oven at 80°C for 3 hours, and bake until completely dry to obtain carbon nanotubes and graphene powder.

[0137] (II) Preparation of electroplating additives:

[0138] S3: Add 35% of a mixture of PEG and TX to 20% water and stir until homogeneous to obtain mixture B;

[0139] S4: Add 17% of a mixture of PVA and TP and 10% of a mixture of GL and CMC to mixture B in S3, control the temperature at 50℃, and stir for 1 hour to obtain mixture C.

[0140] S5: Add 18% water to mixture B of S4, maintain the temperature, and stir for 3 hours to obtain the electroplating additive.

[0141] (III) Preparation of graphene and carbon nanotube-doped silver plating solution:

[0142] S6: Add 2 / 3 volume of pure water to the electroplating tank;

[0143] S7: Add 80-150 g / L potassium cyanide to the pure water in S6, heat to 40 degrees and stir to dissolve it;

[0144] S8: Add 20-50 g / L silver cyanide to the potassium cyanide solution obtained in S6 and dissolve to obtain mixture D;

[0145] S9: Add 15-30 g / L potassium carbonate to mixture D obtained in S7 and dissolve to obtain mixture E;

[0146] S10: Add 70-90 g / L of carbon nanotubes and graphene powder and 5-12 g / L of electroplating additives to mixture E obtained in S9, and stir thoroughly to dissolve to obtain mixture F;

[0147] S11: Add the remaining water to the standard volume of 200L, and cool it to 16-25℃ to obtain the desired graphene and carbon nanotube doped silver plating solution.

[0148] The graphene and carbon nanotube-doped silver plating solution prepared in this invention is used to plate a silver layer on the surface of a pre-plated part. The process parameters to be controlled during electroplating are as follows: pH 12-14, operating temperature 16-25℃, silver ion content in the solution 20-50 g / L, and carbon nanotube and graphene powder content 70-90 g / L. No filtration of the plating solution is required during use; 15 g of carbon nanotube and graphene powder can be added for every 2 kg of silver plated. After electroplating, the conductivity (contact resistance), wear resistance cycle, and Vickers hardness of the product were tested and found to be 0.17 mΩ, 1950 cycles, and 213.5 HV, respectively.

[0149] The graphene and carbon nanotube doped silver plating solution (YCYY-35) prepared by the technical solution of this invention and the products plated by commercially available traditional silver plating solutions X, Y, and Z were all applied to the same workpiece surface using their optimal process parameters. After electroplating, the conductivity (contact resistance), wear resistance (wear resistance cycle), and hardness (Vickers hardness) of the plating layers were tested. Partial optimal results are compared as follows: Figure 4 As shown in the table below.

[0150] The graphene and carbon nanotube-doped silver plating solution prepared by this invention is most notably characterized by the presence of carbon nanotube and graphene powders, which significantly enhance the wear resistance, conductivity, and hardness of the silver plating layer. Dispersants and stabilizers increase the dispersibility and stability of various components in the silver plating solution, resulting in a more uniform and smooth silver layer deposition on the final product surface. Compared to products prepared using traditional cyanide silver plating systems, silver-plated products prepared using this solution exhibit stronger silver adhesion, a smoother surface, better wear resistance, superior conductivity, and higher hardness, thus improving the overall quality of the silver-plated products. The plating layer prepared using the graphene and carbon nanotube-doped silver plating solution of this invention shows significantly improved conductivity, wear resistance, and hardness compared to plating layers prepared using traditional silver plating solutions. Furthermore, the production and use of the graphene and carbon nanotube-doped silver plating solution prepared by this invention do not require high temperatures, resulting in low energy consumption during production and use, facilitating large-scale production and application, and offering excellent economic benefits.

[0151] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a silver plating solution doped with graphene and carbon nanotubes, characterized in that, Includes the following steps: (I) Preparation of carbon nanotube and graphene powders: S1: Weigh 40-65% of graphene and carbon nanotubes in a ratio of 1:1-1.5:1 and put them into a stirrer. Add 15-25% of dispersant and the remainder of organic solvent. Stir for 4-6 hours to dissolve the solids to obtain mixture A. S2: Spread the mixture A obtained in S1 evenly in a tray, place it in an oven at 70-80℃ and bake for 2-3 hours until completely dried to obtain carbon nanotubes and graphene powder; (II) Preparation of electroplating additives: S3: Add 20-35% surfactant to 20% water and stir until homogeneous to obtain mixture B; S4: Add 8-17% dispersant and 5-10% stabilizer to mixture B of S3, control the temperature at 30-50℃, and stir for 1 hour to obtain mixture C; S5: Add the remaining water to mixture C of S4, maintain the temperature and stir for 2-3 hours to obtain the electroplating additive; (III) Preparation of graphene and carbon nanotube-doped silver plating solution: S6: Add 2 / 3 volume of pure water to the electroplating tank; S7: Add 80-150 g / L potassium cyanide to the pure water in S6, heat to 40 degrees and stir to dissolve it; S8: Add 20-50 g / L silver cyanide to the potassium cyanide solution obtained in S7, and dissolve to obtain mixture D; S9: Add 15-30 g / L potassium carbonate to mixture D obtained in S8 and dissolve to obtain mixture E; S10: Add 70-90 g / L of carbon nanotubes and graphene powder and 5-12 g / L of electroplating additives to mixture E obtained in S9, and stir thoroughly to dissolve to obtain mixture F; S11: Add the remaining water to the standard volume of 200L, and cool it to 16-25℃ to obtain the desired graphene and carbon nanotube doped silver plating solution, wherein the pH of the plating solution is 12-14. The graphene and carbon nanotube-doped silver plating solution comprises 20-50 g / L silver cyanide, 80-150 g / L potassium cyanide, 15-30 g / L potassium carbonate, 70-90 g / L carbon nanotube and graphene powder, 5-12 g / L electroplating additive, and the balance water. The carbon nanotube and graphene powder comprises 40-65% graphene and carbon nanotubes in a ratio of 1:1-1.5:1, 15-25% dispersant, and the balance organic solvent. The carbon nanotube and graphene powder is a composite powder formed by mixing graphene and carbon nanotubes in a dispersant and organic solvent and then drying it. The electroplating additive comprises 20-35% surfactant, 8-17% dispersant, 5-10% stabilizer, and the balance water. The dispersant is polyvinyl alcohol (PVA); The organic solvent is one of N,N-dimethylformamide (DMF), tetrahydrofuran (THF), or ethyl acetate (EA); The surfactant is one or more of polyethylene glycol-400 PEG, Triton X-114 TX, or nonylphenol polyoxyethylene ether OP; The stabilizer is one or a mixture of glycerol GL, carboxymethyl cellulose CMC, or sodium stearate SS; The pH of the electroplating solution is 12-14.

2. The method for preparing a graphene and carbon nanotube-doped silver plating solution according to claim 1, characterized in that, The water in the electroplating additive is deionized water, distilled water, or double-distilled water.

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