Nickel alloy nanoelectrode and preparation method and application thereof

Abstract

The application discloses a nickel alloy nano electrode and a preparation method and application thereof, and relates to the technical field of battery technology, and specifically discloses a nickel alloy nano electrode and a preparation method and application thereof.

Description

A nickel alloy nanoelectrode, its preparation method and application Technical Field

[0001] This invention relates to the field of nanoelectrode technology, specifically to a nickel alloy nanoelectrode, its preparation method, and its application. Background Technology

[0002] The rapid development of nanomaterial manufacturing technology has spurred numerous remarkable achievements. In recent years, many researchers have continued to explore the excellent properties of nanomaterials in the field of electrochemistry. Nickel alloy nanomaterials, due to their good chemical stability and conductivity, as well as their ability to provide higher sensitivity and faster response speed, are widely used in the fabrication of nanoelectrodes. Compared with traditional copper electrodes, they have a larger specific surface area, which means that more active surface can be provided within the same size, which is beneficial for enhancing the contact area with the electrolyte, thereby improving the electrochemical reaction rate and transport efficiency.

[0003] In related technologies, common methods for preparing nickel alloy nanomaterial electrodes include physical vapor deposition, chemical vapor deposition, sol-gel method, and electrochemical deposition. These methods allow control over the size, morphology, and structure of the electrode, thereby regulating its electrochemical performance. For example, Ni / Co catalytic electrodes prepared using the constant current electrodeposition method not only possess high specific surface area and stability but also exhibit excellent catalytic hydrogen evolution performance. However, in practical applications, the constant current electrodeposition method requires a demanding production environment and involves complex processes. Furthermore, the preparation process is prone to uneven current density, leading to uneven deposition layer thickness. In addition, due to a relative lack of research on the mechanism of nickel alloy nanoelectrodes, currently prepared nickel alloy electrode materials also suffer from easy oxidation and relatively low electrocatalytic efficiency.

[0004] Therefore, there is still a need to find a nickel alloy nanomaterial electrode material that is simple to prepare, has excellent electrocatalytic effect, and is resistant to high temperature and oxidation. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a nickel alloy nanoelectrode, its preparation method, and its application. The nickel alloy nanoelectrode of this invention exhibits excellent electrochemical performance, reaching 200 mA / cm². 2 At the specified current density, the hydrogen evolution overpotential is below 200mV. In addition, this nickel alloy nanoelectrode has excellent thermal stability and mechanical strength. Moreover, the preparation process is simple and has no special requirements for the preparation environment (such as the electrolyte system) compared to the constant current electrodeposition method. It also has a high film formation rate and can produce high-quality, dense and uniform films.

[0006] In a first aspect, the present invention provides a nickel alloy nanoelectrode, comprising the following steps:

[0007] S1. Pre-treat the nickel foam to remove surface impurities and set aside for later use;

[0008] S2. Under an inert atmosphere, using the pretreated nickel foam as a substrate, and then using metallic nickel and metallic copper or metallic molybdenum as targets, magnetron sputtering is performed to deposit a nickel / copper composite layer or a nickel / molybdenum composite layer on the surface of the nickel foam.

[0009] S3. Under an inert atmosphere, using the composite-layered nickel foam obtained in step S2 as a substrate, magnetron sputtering is performed on an aluminum or chromium target. After hydrothermal oxidation, the product is dried.

[0010] As one embodiment of the present invention, in step S1, the pretreatment includes sequentially treating the foamed nickel with hydrochloric acid and acetone, and then washing it with deionized water and ethanol until it is neutral.

[0011] As one embodiment of the present invention, the pore size distribution of the nickel foam is 10 to 40 micrometers; further, the porosity of the nickel foam is greater than 95%.

[0012] Better porosity helps increase the active surface area of ​​nickel foam. As an electrocatalytic material, nickel foam's catalytic reaction involves electron transfer processes. High porosity provides more electron transfer channels, reduces resistance to electron transfer paths, promotes electron flow, and thus improves the efficiency and response rate of the catalytic reaction.

[0013] As one embodiment of the present invention, in step S2, during the magnetron sputtering process, the cavity vacuum degree is 0.8 to 1.5 Pa, the heating temperature is 500 to 650°C, and the base rotation speed is 10 to 15 rpm.

[0014] As one embodiment of the present invention, in step S2, when the metallic nickel is used as the target material, the magnetron sputtering power is 30-50W and the sputtering time is 2-8min.

[0015] As one embodiment of the present invention, the magnetron sputtering is radio frequency magnetron sputtering, wherein the radio frequency frequency is 8 to 12 MHz.

[0016] Radio frequency magnetron sputtering has a superior deposition rate compared to conventional DC magnetron sputtering, and can provide better uniform and continuous thin film deposition. Furthermore, by adjusting the energy and angle of the ion beam, the deposition of the thin film can be controlled to ensure that it is uniformly distributed across the entire substrate surface.

[0017] As one embodiment of the present invention, in step S2, when the metallic copper or metallic molybdenum is used as the target material, the magnetron sputtering power is 60-80W and the sputtering time is 5-10min.

[0018] In an embodiment of the present invention, when the magnetron sputtering power is too high, the electrocatalytic effect of the prepared nickel alloy nanoelectrode is significantly reduced. For example, when using copper or molybdenum as the target material, and adjusting the power to 100W, cracks appear in the prepared nickel alloy nanoelectrode film. Further testing of its electrocatalytic performance revealed that it is at a lower efficiency than that at 200 mA / cm². 2 At the specified current density, the hydrogen evolution overpotential reaches 237 mV, which is far lower than the electrocatalytic effect of the nickel alloy nanoelectrode of this invention.

[0019] In one embodiment of the present invention, the magnetron sputtering is DC magnetron sputtering.

[0020] As one embodiment of the present invention, after the magnetron sputtering is completed, the temperature is reduced at a rate of 3 to 6 °C / min.

[0021] As one embodiment of the present invention, in step S3, during the magnetron sputtering process, the cavity vacuum degree is 0.8 to 1.2 Pa, the heating temperature is 60 to 80°C, the sputtering power is 60 to 90 W, and the sputtering time is 30 to 120 s.

[0022] As one embodiment of the present invention, in step S3, the magnetron sputtering is selected from radio frequency magnetron sputtering or DC magnetron sputtering; preferably radio frequency magnetron sputtering, wherein the radio frequency frequency is 8 to 12 MHz.

[0023] In one embodiment of the present invention, in step S3, the temperature of the hydrothermal oxidation treatment is 60-100°C and the time is 5-8 hours.

[0024] In one embodiment of the present invention, in step S2 and / or step S3, the inert gas includes nitrogen or argon.

[0025] As one embodiment of the present invention, the thickness of the nickel / copper composite layer or the nickel / molybdenum composite layer is 20 to 50 μm.

[0026] In one embodiment of the present invention, the thickness of the alumina film layer formed in step S3 is 50-100 nm.

[0027] In one embodiment of the present invention, in step S3, the drying is performed under vacuum at 70°C to 80°C for 2 to 6 hours.

[0028] In a second aspect, the present invention provides a nickel alloy nanoelectrode, which is prepared by the preparation method described in the first aspect.

[0029] As one embodiment of the present invention, the nickel alloy nanoelectrode comprises a substrate layer, a solid solution reinforced conductive layer, and a nano oxide layer.

[0030] A third aspect of the present invention provides the application of the preparation method as described in any of the first aspects or the nickel alloy nanoelectrode as described in the second aspect in the preparation of supercapacitors.

[0031] Compared with the prior art, the preparation method of the nickel alloy nanoelectrode of the present invention and the nickel alloy nanoelectrode obtained therefrom have at least the following beneficial effects:

[0032] (1) The nickel alloy nanoelectrode of the present invention has excellent thermal stability and mechanical strength. The nickel alloy nanoelectrode is doped with a Ni-Cu or Ni-Mo composite layer by a dual magnetron sputtering process on the basis of nickel foam. Both Cu and Mo are elements that help improve thermal stability and mechanical strength. They are doped on the surface of nickel foam by solid solution. Compared with the undoped group, it can significantly provide the thermal stability and mechanical strength of the electrode material.

[0033] (2) The nickel alloy nanoelectrode of this invention exhibits excellent electrocatalytic activity. It is generally believed that nickel alloy nanoelectrodes have better chemical stability than conventional copper electrodes, resisting the effects of oxidation, corrosion, and other environmental conditions, as well as higher mechanical strength, hardness, and wear resistance. However, in terms of the electrical conductivity of the material itself, nickel alloys may not be as conductive as copper. Therefore, existing nickel alloy nanoelectrodes suffer from low conductivity. The solution proposed in this application effectively solves the technical problem of low conductivity in nickel alloy nanoelectrodes by rationally doping with solid solution-enhanced conductive elements. It possesses better chemical stability, mechanical strength, hardness, and wear resistance, while also exhibiting superior electrocatalytic activity.

[0034] (3) The nickel alloy nanoelectrode of the present invention has a simple preparation process. Compared with the constant current electrodeposition method, it has no special requirements for the preparation environment (such as the electrolyte system). It also has a high film formation rate and can produce high-quality, dense and uniform films. In addition, the obtained nickel alloy nanoelectrode does not require passivation treatment in subsequent use and has excellent oxidation resistance. Attached Figure Description

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0036] Figure 1 is a schematic diagram of the nickel alloy nanoelectrode of the present invention. Detailed Implementation

[0037] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0038] In this invention, the terms "preferred," "more preferably," etc., refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of the invention.

[0039] In this invention, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0040] In this invention, the nickel foam was purchased from Suzhou Maozhen New Material Technology Co., Ltd., and its porosity is approximately 98% with a pore size distribution of approximately 20 micrometers. In other embodiments, unless specific conditions are specified, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0041] The following examples illustrate a nickel alloy nanoelectrode and its preparation method according to embodiments of this application.

[0042] Example 1 (Nickel + Nickel / Copper + Aluminum)

[0043] This embodiment provides a nickel alloy nanoelectrode and its preparation method. The nickel alloy nanoelectrode of this embodiment is obtained by sequentially sputtering a solid solution-reinforced conductive layer and a nano-oxide layer using nickel as the substrate material and a dual magnetron sputtering process. The solid solution-reinforced conductive layer is a nickel / copper composite layer with a thickness controlled at approximately 20 μm; the nano-oxide layer is an aluminum oxide layer with a thickness controlled at approximately 50 nm.

[0044] The preparation method of the above-mentioned nickel alloy nanoelectrode specifically includes the following steps:

[0045] (1) Substrate pretreatment:

[0046] First, immerse the cut nickel foam (5cm×5cm) in a beaker containing deionized water and sonicate for 10 minutes. Then, immerse the nickel foam in a 3M HCl solution for 10 minutes to acidify and remove oxides from the nickel surface. Next, immerse the nickel foam in an acetone solution for 10 minutes to remove surface oil stains. Finally, wash the nickel foam with deionized water and ethanol in sequence until it is neutral, and then blow it dry for later use.

[0047] (2) Preparation of solid solution reinforced conductive layer:

[0048] The pretreated nickel foam was placed on a sputtering substrate as a substrate. Under a high-purity argon atmosphere, a nickel target (purity greater than 99.9%) was sputtered sequentially using RF magnetron sputtering and a copper target (purity greater than 99.9%) using DC sputtering. During sputtering, the vacuum degree was 1.5 Pa, the base heating temperature was 550℃, the base rotation speed was about 15 rpm, the nickel target sputtering power was 40 W, the RF frequency was 10 MHz, and the sputtering time was 5 min; the copper target sputtering power was 60 W, and the sputtering time was 8 min. After sputtering, the temperature was reduced to room temperature at a rate of 5℃ / min, resulting in a Ni-Cu composite layer (i.e., a solid solution reinforced conductive layer) with a thickness of about 20 μm.

[0049] (3) Nano-oxide layer:

[0050] Using the aforementioned nickel foam with a solid solution-reinforced conductive layer as a substrate, and 99.99% pure aluminum as a target, DC magnetron sputtering was performed under a high-purity argon atmosphere. The sputtering parameters were set as follows: vacuum level 1.0 Pa, chamber temperature 60℃, sputtering power 80 W, and sputtering time 30 s. After sputtering, the material was removed and placed in 80℃ hot water for oxidation reaction for 6 hours. After vacuum drying, the nickel alloy nanoelectrode was obtained.

[0051] Electrochemical tests were conducted using a CHI 660D electrochemical workstation with a three-electrode system. The specific method is as follows: the nickel alloy nanoelectrode prepared in this embodiment was used as the working electrode, a platinum sheet as the auxiliary electrode, mercury / mercury oxide as the reference electrode, and a 30wt% NaOH solution as the electrolyte. The test temperature was 25℃, and the hydrogen evolution polarization curve was obtained. Note: Before the test, high-purity nitrogen was bubbled into the NaOH solution for 15 min to remove some impurity gases dissolved in the electrolyte. The test results showed that the nickel alloy nanoelectrode prepared in this embodiment has good catalytic hydrogen evolution activity, especially at 200 mA / cm². 2 At the current density, the hydrogen evolution overpotential is 168 mV.

[0052] Furthermore, using the same three-electrode system, at a temperature of 80℃ and a current density of 200 mA / cm², 2Under these conditions, continuous electrolysis for 120 hours showed that the voltage curve was stable with no obvious fluctuations, indicating that the nickel alloy nanoelectrode prepared in this embodiment has excellent stability.

[0053] Example 2 (Nickel + Nickel / Mo + Aluminum)

[0054] This embodiment provides a nickel alloy nanoelectrode and its preparation method. The nickel alloy nanoelectrode of this embodiment is obtained by sequentially sputtering a solid solution-reinforced conductive layer and a nano-oxide layer using nickel as the substrate material and a dual magnetron sputtering process. The solid solution-reinforced conductive layer is a nickel / molybdenum composite layer with a thickness controlled at approximately 20 μm; the nano-oxide layer is an aluminum oxide layer with a thickness controlled at approximately 50 nm.

[0055] The preparation method of the above-mentioned nickel alloy nanoelectrode specifically includes the following steps:

[0056] (1) Substrate pretreatment:

[0057] First, immerse the cut nickel foam (5cm×5cm) in a beaker containing deionized water and sonicate for 10 minutes. Then, immerse the nickel foam in a 3M HCl solution for 10 minutes to acidify and remove oxides from the nickel surface. Next, immerse the nickel foam in an acetone solution for 10 minutes to remove surface oil stains. Finally, wash the nickel foam with deionized water and ethanol in sequence until it is neutral, and then blow it dry for later use.

[0058] (2) Preparation of solid solution reinforced conductive layer:

[0059] The pretreated nickel foam was placed on a sputtering substrate as a substrate. Under a high-purity argon atmosphere, a nickel target (purity greater than 99.9%) was sputtered sequentially using radio frequency magnetron sputtering and a molybdenum target (purity greater than 99.9%). During sputtering, the vacuum degree was 1.5 Pa, the base heating temperature was 650 °C, the base rotation speed was about 15 rpm, the nickel target sputtering power was 40 W, the radio frequency was 10 MHz, and the sputtering time was 5 min; the molybdenum target sputtering power was 60 W, and the sputtering time was 8 min. After sputtering, the temperature was reduced to room temperature at a rate of 5 °C / min, resulting in a Ni-Mo composite layer (i.e., a solid solution reinforced conductive layer) with a thickness of about 20 μm.

[0060] (3) Nano-oxide layer:

[0061] Using the aforementioned nickel foam with a solid solution-reinforced conductive layer as a substrate, and 99.99% pure aluminum as a target, DC magnetron sputtering was performed under a high-purity argon atmosphere. The sputtering parameters were set as follows: vacuum level 1.0 Pa, chamber temperature 60℃, sputtering power 80 W, and sputtering time 30 s. After sputtering, the material was removed and placed in 80℃ hot water for oxidation reaction for 6 hours. After vacuum drying, the nickel alloy nanoelectrode was obtained.

[0062] The electrochemical performance and stability of the nickel alloy nanoelectrode were tested using the detection method of Example 1, showing that it remained stable at 200 mA / cm². 2 At the specified current density, the hydrogen evolution overpotential was 189 mV, which is higher than that of the nickel alloy nanoelectrode prepared in Example 1, presumably related to the conductivity of the solid solution-reinforced conductive layer. Further, at a temperature of 80 °C and a current density of 200 mA / cm², the hydrogen evolution overpotential was also increased. 2 Under these conditions, after continuous electrolysis for 120 hours, the voltage curve remained stable without significant fluctuations, indicating that the nickel alloy nanoelectrode prepared by the dual magnetron sputtering process has good stability.

[0063] Example 3 (Nickel + Nickel / Copper + Chromium)

[0064] This embodiment provides a nickel alloy nanoelectrode and its preparation method. The nickel alloy nanoelectrode of this embodiment is obtained by sequentially sputtering a solid solution-reinforced conductive layer and a nano-oxide layer using nickel as the substrate material and a dual magnetron sputtering process. The solid solution-reinforced conductive layer is a nickel / copper composite layer with a thickness controlled at approximately 20 μm; the nano-oxide layer is a chromium oxide layer with a thickness controlled at approximately 50 nm.

[0065] The preparation method of the above-mentioned nickel alloy nanoelectrode specifically includes the following steps:

[0066] (1) Substrate pretreatment:

[0067] First, immerse the cut nickel foam (5cm×5cm) in a beaker containing deionized water and sonicate for 10 minutes. Then, immerse the nickel foam in a 3M HCl solution for 10 minutes to acidify and remove oxides from the nickel surface. Next, immerse the nickel foam in an acetone solution for 10 minutes to remove surface oil stains. Finally, wash the nickel foam with deionized water and ethanol in sequence until it is neutral, and then blow it dry for later use.

[0068] (2) Preparation of solid solution reinforced conductive layer:

[0069] The pretreated nickel foam was placed on a sputtering substrate as a substrate. Under a high-purity argon atmosphere, a nickel target (purity greater than 99.9%) was sputtered sequentially using radio frequency magnetron sputtering and a copper target (purity greater than 99.9%). During sputtering, the vacuum degree was 1.5 Pa, the base heating temperature was 550℃, the base rotation speed was about 15 rpm, the nickel target sputtering power was 40 W, the radio frequency was 10 MHz, and the time was 5 min; the copper target sputtering power was 60 W, and the sputtering time was 8 min. After sputtering, the temperature was reduced to room temperature at a rate of 5℃ / min to obtain a Ni-Cu composite layer with a thickness of about 20 μm.

[0070] (3) Nano-oxide layer:

[0071] Using the aforementioned nickel foam with a solid solution-reinforced conductive layer as a substrate, and 99.99% pure metallic chromium as a target, DC magnetron sputtering was performed under a high-purity argon atmosphere. The sputtering parameters were set as follows: vacuum degree 1.0 Pa, chamber temperature 80℃, sputtering power 80 W, and sputtering time 30 s. After sputtering, the material was removed and placed in 80℃ hot water for oxidation reaction for 6 hours. After vacuum drying, the nickel alloy nanoelectrode was obtained.

[0072] The electrochemical performance and stability of the nickel alloy nanoelectrode were tested using the detection method of Example 1, showing that it remained stable at 200 mA / cm². 2 At the specified current density, the hydrogen evolution overpotential was 171 mV, comparable to that of the nickel alloy nanoelectrode prepared in Example 1. Further, at a temperature of 80 °C and a current density of 200 mA / cm², the hydrogen evolution overpotential was [not specified]. 2 Under these conditions, after continuous electrolysis for 120 hours, the voltage curve was relatively stable with slight fluctuations. The voltage increased by about 0.1V compared to the initial stable voltage, which is presumably related to the stability of the nano-oxide layer.

[0073] Example 4 (Nickel + Nickel / Copper + Aluminum, with increased magnetron sputtering time)

[0074] This embodiment provides a nickel alloy nanoelectrode and its preparation method. The nickel alloy nanoelectrode of this embodiment is obtained by sequentially sputtering a solid solution-reinforced conductive layer and a nano-oxide layer using nickel as the substrate material and a dual magnetron sputtering process. The solid solution-reinforced conductive layer is a nickel / copper composite layer with a thickness controlled at approximately 50 μm; the nano-oxide layer is an aluminum oxide layer with a thickness controlled at approximately 100 nm.

[0075] The preparation method of the above-mentioned nickel alloy nanoelectrode specifically includes the following steps:

[0076] (1) Substrate pretreatment:

[0077] First, immerse the cut nickel foam (5cm×5cm) in a beaker containing deionized water and sonicate for 10 minutes. Then, immerse the nickel foam in a 3M HCl solution for 10 minutes to acidify and remove oxides from the nickel surface. Next, immerse the nickel foam in an acetone solution for 10 minutes to remove surface oil stains. Finally, wash the nickel foam with deionized water and ethanol in sequence until it is neutral, and then blow it dry for later use.

[0078] (2) Preparation of solid solution reinforced conductive layer:

[0079] The pretreated nickel foam was placed on a sputtering substrate as a substrate. Under a high-purity argon atmosphere, a nickel target (purity greater than 99.9%) was sputtered sequentially using radio frequency magnetron sputtering and a copper target (purity greater than 99.9%). During sputtering, the vacuum degree was 1.2 Pa, the base heating temperature was 550℃, the base rotation speed was about 15 rpm, the nickel target sputtering power was 50 W, the radio frequency was 10 MHz, and the time was 8 min; the copper target sputtering power was 70 W, and the sputtering time was 12 min. After sputtering, the temperature was reduced to room temperature at a rate of 5℃ / min to obtain a Ni-Cu composite layer with a thickness of about 50 μm.

[0080] (3) Nano-oxide layer:

[0081] Using the aforementioned nickel foam with a solid solution-reinforced conductive layer as a substrate, and 99.99% pure aluminum as a target, DC magnetron sputtering was performed under a high-purity argon atmosphere. The sputtering parameters were set as follows: vacuum level 1.0 Pa, chamber temperature 60℃, sputtering power 80 W, and sputtering time 60 s. After sputtering, the material was removed and placed in 80℃ hot water for oxidation reaction for 6 hours. After vacuum drying, the nickel alloy nanoelectrode was obtained.

[0082] The electrochemical performance and stability of the nickel alloy nanoelectrode were tested using the detection method described in Example 1, showing that it maintains a stability at 200 mA / cm². 2 At the specified current density, the hydrogen evolution overpotential was 162 mV, slightly lower than that of the nickel alloy nanoelectrode prepared in Example 1, presumably related to improved conductivity. Further, at a temperature of 80 °C and a current density of 200 mA / cm², the hydrogen evolution overpotential was also measured. 2 Under these conditions, after continuous electrolysis for 120 hours, its voltage curve was relatively stable with no obvious fluctuations, which was comparable to the nickel alloy nanoelectrode prepared in Example 1.

[0083] Example 5 (Nickel + Nickel / Copper + Aluminum, DC Magnetron Sputtering)

[0084] This embodiment provides a nickel alloy nanoelectrode and its preparation method. The nickel alloy nanoelectrode of this embodiment is obtained by sequentially sputtering a solid solution-reinforced conductive layer and a nano-oxide layer using nickel as the substrate material and a magnetron sputtering process. The solid solution-reinforced conductive layer is a nickel / copper composite layer with a thickness controlled at approximately 20 μm; the nano-oxide layer is an aluminum oxide layer with a thickness controlled at approximately 50 nm.

[0085] The preparation method of the above-mentioned nickel alloy nanoelectrode specifically includes the following steps:

[0086] (1) Substrate pretreatment:

[0087] First, immerse the cut nickel foam (5cm×5cm) in a beaker containing deionized water and sonicate for 10 minutes. Then, immerse the nickel foam in a 3M HCl solution for 10 minutes to acidify and remove oxides from the nickel surface. Next, immerse the nickel foam in an acetone solution for 10 minutes to remove surface oil stains. Finally, wash the nickel foam with deionized water and ethanol in sequence until it is neutral, and then blow it dry for later use.

[0088] (2) Preparation of solid solution reinforced conductive layer:

[0089] The pretreated nickel foam was placed on a sputtering substrate as a substrate. Under a high-purity argon atmosphere, nickel (purity greater than 99.9%) and copper (purity greater than 99.9%) targets were sputtered sequentially using magnetron sputtering. The vacuum degree during sputtering was 1.5 Pa, the base heating temperature was 550 °C, the base rotation speed was about 15 rpm, the nickel target sputtering power was 40 W, and the time was 5 min; the copper target sputtering power was 60 W, and the sputtering time was 8 min. After sputtering, the temperature was reduced to room temperature at a rate of 5 °C / min to obtain a Ni-Cu composite layer with a thickness of about 20 μm.

[0090] (3) Nano-oxide layer:

[0091] Using the aforementioned nickel foam with a solid solution-reinforced conductive layer as a substrate, and 99.99% pure aluminum as a target, DC magnetron sputtering was performed under a high-purity argon atmosphere. The sputtering parameters were set as follows: vacuum level 1.0 Pa, chamber temperature 60℃, sputtering power 80 W, and sputtering time 30 s. After sputtering, the material was removed and placed in 80℃ hot water for oxidation reaction for 6 hours. After vacuum drying, the nickel alloy nanoelectrode was obtained.

[0092] The electrochemical performance and stability of the nickel alloy nanoelectrode were tested using the detection method described in Example 1, showing that it maintains a stability at 200 mA / cm². 2At the specified current density, the hydrogen evolution overpotential was 192 mV, which is higher than that of the nickel alloy nanoelectrode prepared in Example 1, presumably related to the conductivity of the solid solution-reinforced conductive layer. Further, at a temperature of 80 °C and a current density of 200 mA / cm², the hydrogen evolution overpotential was also increased. 2 Under these conditions, after continuous electrolysis for 120 hours, the voltage curve was relatively stable with slight fluctuations. It increased by 0.2V compared to the early stage of electrolysis, which is presumably related to the magnetron sputtering process. However, the overall decrease was not significant, and it still maintained good performance and structural stability.

[0093] Comparative Example 1: Pure Nickel Foam

[0094] This comparative example provides a nickel alloy electrode, which is obtained by magnetron sputtering of a nickel layer of about 20 μm on a nickel foam base. The difference from Example 1 is that copper and aluminum target sputtering treatments were not performed.

[0095] The electrochemical performance and stability of the nickel alloy nanoelectrode were tested using the detection method described in Example 1, showing that it maintains a stability at 200 mA / cm². 2 At the current density, the hydrogen evolution overpotential is 294 mV, which is 105 mV positively shifted compared to the hydrogen evolution overpotential of the nickel alloy nanoelectrode prepared in Example 1.

[0096] Furthermore, at a temperature of 80℃ and a current density of 200 mA / cm², 2 Under these conditions, after continuous electrolysis for 120 hours, the voltage curve showed a significant shift, increasing by 0.6V relative to the initial stable voltage. Furthermore, the quality improved before and after continuous electrolysis, which is presumably related to the oxidation of the surface nickel layer.

[0097] Comparative Example 2: Nickel alloy nanoelectrode (without nano-oxide layer)

[0098] This comparative example provides a nickel alloy nanoelectrode and its preparation method. The nickel alloy nanoelectrode is obtained by sputtering a solid solution-reinforced conductive layer using nickel as the substrate material and a dual magnetron sputtering process. The solid solution-reinforced conductive layer is a nickel / copper composite layer with a thickness controlled at approximately 20 μm. The difference between this nickel alloy nanoelectrode and Example 1 is the absence of a nano-oxide layer.

[0099] The preparation method of the above-mentioned nickel alloy nanoelectrode specifically includes the following steps:

[0100] (1) Substrate pretreatment:

[0101] First, immerse the cut nickel foam (5cm×5cm) in a beaker containing deionized water and sonicate for 10 minutes. Then, immerse the nickel foam in a 3M HCl solution for 10 minutes to acidify and remove oxides from the nickel surface. Next, immerse the nickel foam in an acetone solution for 10 minutes to remove surface oil stains. Finally, wash the nickel foam with deionized water and ethanol in sequence until it is neutral, and then blow it dry for later use.

[0102] (2) Preparation of solid solution reinforced conductive layer:

[0103] The pretreated nickel foam was placed on a sputtering substrate as a substrate. Under a high-purity argon atmosphere, a nickel target (purity greater than 99.9%) was sputtered sequentially using RF magnetron sputtering and a copper target (purity greater than 99.9%). During sputtering, the vacuum degree was 1.5 Pa, the base heating temperature was 550℃, the base rotation speed was about 15 rpm, the nickel target sputtering power was 80 W, the RF frequency was 10 MHz, and the sputtering time was 60 s; the copper target sputtering power was 120 W, and the sputtering time was 90 s. After sputtering, the temperature was reduced to room temperature at a rate of 5℃ / min to obtain a Ni-Cu composite layer with a thickness of about 20 μm.

[0104] The electrochemical performance and stability of the nickel alloy nanoelectrode were tested using the detection method described in Example 1, showing that it maintains a stability at 200 mA / cm². 2 At a current density of 200 mA / cm², the hydrogen evolution overpotential was 207 mV, slightly higher than that of the nickel alloy nanoelectrode prepared in Example 1. This is presumably related to the excessive oxidation of the surface copper layer, and the copper oxide leads to a decrease in the electrochemical performance of the electrode, affecting its catalytic activity and reaction efficiency. Further, at a temperature of 80 °C and a current density of 200 mA / cm², the hydrogen evolution overpotential was further improved. 2 Under these conditions, after continuous electrolysis for 120 hours, the voltage curve fluctuated significantly, increasing by about 0.8V relative to the initial voltage. This indicates that simple solid solution strengthening of the conductive layer is not conducive to improving the electrical performance stability of nickel-based electrodes. However, adding a nano-alumina layer helps to increase the effective surface area of ​​the electrode, providing more active sites for catalytic reactions. Furthermore, alumina has good chemical stability and mechanical strength, which can protect the electrode surface from corrosion and mechanical damage.

[0105] Comparative Example 3: Nickel alloy nanoelectrode (without solid solution reinforced conductive layer)

[0106] This comparative example provides a nickel alloy nanoelectrode and its preparation method. The nickel alloy nanoelectrode is obtained by sputtering a nano-oxide layer using nickel as the substrate material and a magnetron sputtering process. This nano-oxide layer is an aluminum oxide layer with a thickness controlled at approximately 50 nm. The difference between this nickel alloy nanoelectrode and Example 1 is the absence of a solid solution-reinforced conductive layer.

[0107] The preparation method of the above-mentioned nickel alloy nanoelectrode specifically includes the following steps:

[0108] (1) Substrate pretreatment:

[0109] First, immerse the cut nickel foam (5cm×5cm) in a beaker containing deionized water and sonicate for 10 minutes. Then, immerse the nickel foam in a 3M HCl solution for 10 minutes to acidify and remove oxides from the nickel surface. Next, immerse the nickel foam in an acetone solution for 10 minutes to remove surface oil stains. Finally, wash the nickel foam with deionized water and ethanol in sequence until it is neutral, and then blow it dry for later use.

[0110] (2) Nano-oxide layer:

[0111] Using the pretreated nickel foam as a substrate and 99.99% pure aluminum as a target, DC magnetron sputtering was performed under a high-purity argon atmosphere. The sputtering parameters were set as follows: vacuum level 1.0 Pa, chamber temperature 60℃, sputtering power 80 W, and sputtering time 30 s. After sputtering, the material was removed and placed in 80℃ hot water for oxidation reaction for 6 hours. After vacuum drying, the nickel alloy nanoelectrode was obtained.

[0112] The electrochemical performance and stability of the nickel alloy nanoelectrode were tested using the detection method described in Example 1, showing that it maintains a stability at 200 mA / cm². 2 At a current density of 200 mA / cm², the hydrogen evolution overpotential was 258 mV, which is significantly higher than that of the nickel alloy nanoelectrode prepared in Example 1, presumably related to the decrease in conductivity. Further, at a temperature of 80 °C and a current density of 200 mA / cm², the hydrogen evolution overpotential was also significantly increased. 2 Under these conditions, after continuous electrolysis for 120 hours, its voltage curve fluctuated relatively smoothly, indicating that it has good stability.

[0113] In summary, this invention provides a nickel alloy nanoelectrode, its preparation method, and its application. The nickel alloy nanoelectrode is more practical than existing copper material electrodes, has better high-temperature resistance, is less prone to oxidation, and its preparation method is relatively simple, thus having broad application prospects.

[0114] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. The above description is only a preferred embodiment of the present invention. Any equivalent substitutions or changes made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a nickel alloy nanoelectrode, characterized in that: Includes the following steps: S1. Pre-treat the nickel foam to remove surface impurities and set aside for later use; S2. Under an inert atmosphere, using the pretreated nickel foam as a substrate, magnetron sputtering is performed with metallic nickel and metallic copper or metallic molybdenum as targets to deposit a nickel / copper composite layer or a nickel / molybdenum composite layer on the surface of the nickel foam; S3. Under an inert atmosphere, using the nickel foam containing the composite layer obtained in step S2 as a substrate, magnetron sputtering is performed with an aluminum or chromium target, followed by hydrothermal oxidation and drying; In step S2, during the magnetron sputtering process, the cavity vacuum degree is 0.8~1.5 Pa, the heating temperature is 500~650℃, and the base rotation speed is 10~15 rpm; In step S2, when using metallic nickel as the target, the magnetron sputtering power is The sputtering power is 30~50W, and the sputtering time is 2~8min; the magnetron sputtering is radio frequency magnetron sputtering, wherein the radio frequency frequency is 8~12MHz; in step S2, when the metallic copper or metallic molybdenum is used as the target material, the magnetron sputtering power is 60~80W, and the sputtering time is 5~10min; the magnetron sputtering is DC magnetron sputtering; in step S3, during the magnetron sputtering process, the cavity vacuum degree is 0.8~1.2Pa, the heating temperature is 60~80℃, the sputtering power is 60~90W, and the sputtering time is 30~120s; in step S3, the hydrothermal oxidation treatment temperature is 60~100℃, and the time is 5~8h.

2. The preparation method according to claim 1, characterized in that: In step S1, the pretreatment includes sequentially treating the nickel foam with hydrochloric acid and acetone, and then washing it with deionized water and ethanol until it is neutral.

3. The preparation method according to any one of claims 1 to 2, characterized in that: The thickness of the nickel / copper composite layer or nickel / molybdenum composite layer is 20~50μm.

4. A nickel alloy nanoelectrode, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 3.

5. The preparation method according to any one of claims 1 to 3 or the application of the nickel alloy nanoelectrode according to claim 4 in the preparation of supercapacitors.

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