Alkaline hydrogen production electrode, preparation method thereof and water electrolysis hydrogen production device

Abstract

The invention provides an alkaline hydrogen production electrode, a preparation method thereof and a water electrolysis hydrogen production device, and relates to the field of water electrolysis hydrogen production. The preparation method of the alkaline hydrogen production electrode comprises the following steps: forming the hydrogen evolution active layer on the substrate by electroplating; the substrate with the hydrogen evolution active layer is etched, so that a micro-channel structure is formed on the surface of the hydrogen evolution active layer, and the alkaline hydrogen production electrode is obtained; wherein electroplating liquid used for electroplating comprises a main active component and a secondary active component, the main active component comprises nickel salt, and the secondary active component comprises at least one of ferric salt, cobalt salt, copper salt, manganese salt and molybdenum salt. According to the invention, the generation of a large number of active sites and the formation of abundant micro-channel structures can be simultaneously realized on the surface of the electrode through etching, the catalytic activity of the electrode is improved, and the influence of concentration polarization is weakened. Moreover, the transition region between the substrate and the hydrogen evolution active layer is not affected in the etching process, and the transition region between the substrate and the hydrogen evolution active layer has high binding force strength, so that the electrode can stably operate for a long time.

Description

Technical Field

[0001] The present application relates to the field of hydrogen production by water electrolysis, and in particular to an alkaline hydrogen production electrode and a preparation method thereof, and a hydrogen production device by water electrolysis. Background Art

[0002] In alkaline water electrolysis hydrogen production technology, non-precious metal electrodes are key components, and their performance has an important impact on hydrogen production efficiency and cost. However, existing non-precious metal electrodes have several technical problems, which limit their widespread application in alkaline water electrolyzers.

[0003] First, non-precious metal electrodes have limitations in catalytic activity. Compared with precious metal catalysts, they require higher overpotentials to drive water electrolysis reactions, resulting in a significant increase in energy consumption and increased hydrogen production costs.

[0004] Secondly, the catalyst stability of non-precious metal electrodes is insufficient. After long-term operation or in complex environmental conditions, the active sites on the electrode surface will gradually decrease, and the catalytic efficiency will decrease accordingly. This performance degradation phenomenon seriously affects the durability and reliability of the electrode.

[0005] Furthermore, poor contact between the electrode and the electrolyte is also a key problem in the prior art. This poor contact can lead to the occurrence of concentration polarization, further inhibiting the electrolysis reaction and reducing the electrode efficiency. Summary of the invention

[0006] The purpose of the present application is to provide an alkaline hydrogen production electrode and a preparation method thereof and a water electrolysis hydrogen production device to solve the above-mentioned problems.

[0007] To achieve the above objectives, this application adopts the following technical solutions:

[0008] A method for preparing an alkaline hydrogen production electrode, comprising:

[0009] Forming a hydrogen evolution active layer on the substrate by electroplating;

[0010] Etching the substrate having the hydrogen evolution active layer to form a microchannel structure on the surface of the hydrogen evolution active layer to obtain an alkaline hydrogen production electrode;

[0011] The electroplating solution used in the electroplating comprises a main active ingredient and a secondary active ingredient, wherein the main active ingredient comprises a nickel salt, and the secondary active ingredient comprises at least one of an iron salt, a cobalt salt, a copper salt, a manganese salt, and a molybdenum salt.

[0012] According to an embodiment of the present application, the substrate includes any one of a nickel mesh, a nickel foam, a nickel felt, and a carbon felt, the mesh number of the nickel mesh is 20-200 meshes, the porosity of the nickel foam is 70%-99%, the thickness of the nickel felt is 0.5-5 mm, and the density of the carbon felt is 0.1-0.5 g / cm 3 ;

[0013] And / or, the electroplating anode includes any one of a titanium plate and a graphite plate;

[0014] and / or, the molar ratio of the metal element in the primary active ingredient to the metal element in the secondary active ingredient is 5:1 to 5:4;

[0015] And / or, the concentration of the electroplating solution is 0.1-2 mol / L;

[0016] And / or, the electroplating temperature is 20-50°C.

[0017] According to an embodiment of the present application, the pH value of the electroplating solution is 2-6.

[0018] According to the embodiment of the present application, the electroplating current is 0.01-1A / cm 2 .

[0019] According to an embodiment of the present application, the electroplating time is 10 min-5 h.

[0020] According to an embodiment of the present application, the etching method includes any one of electrolysis, chemical etching, plasma etching, and laser etching.

[0021] According to an embodiment of the present application, when the substrate having the hydrogen evolution active layer is etched by electrolysis, the cathode of the electrolysis is the substrate having the hydrogen evolution active layer, the anode of the electrolysis is any one of a titanium plate and a graphite plate, and the electrolyte of the electrolysis includes a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 1%-75%;

[0022] And / or, the electrolysis temperature is 20-60°C.

[0023] According to the embodiment of the present application, the current density of the electrolysis is 0.5-2A / cm 2 .

[0024] According to an embodiment of the present application, the electrolysis process adopts a constant current mode, and the voltage change is detected in real time. When it is observed that the voltage remains stable within 5-15 minutes and no longer continues to decrease, the electrolysis process is stopped.

[0025] The present application also provides an alkaline hydrogen production electrode, which is prepared by the preparation method of the alkaline hydrogen production electrode described above.

[0026] The present application also provides a water electrolysis hydrogen production device, including an alkaline hydrogen production electrode prepared by the preparation method of the alkaline hydrogen production electrode described above or including the alkaline hydrogen production electrode described above.

[0027] Compared with the prior art, the beneficial effects of this application include:

[0028] The present application can simultaneously generate a large number of active sites and form a rich microchannel structure on the electrode surface through etching, which greatly improves the catalytic activity of the electrode and effectively reduces the influence of concentration polarization. In addition, the transition area between the substrate and the hydrogen evolution active layer will not be affected during the etching process, ensuring the strength of the bonding between the two, so that the electrode can operate stably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0030] Figure 1 This is an optical microscope image of the electrode prepared in Example 1;

[0031] Figure 2 This is an optical microscope picture of the electrode prepared in Comparative Example 1. DETAILED DESCRIPTION

[0032] As used herein:

[0033] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0034] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0035] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0036] In these examples, parts and percentages are by mass unless otherwise indicated.

[0037] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0038] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0039] In order to better explain the technical solution provided by this application, before the embodiments, the technical solution is first described as a whole, as follows:

[0040] A method for preparing an alkaline hydrogen production electrode, comprising:

[0041] Forming a hydrogen evolution active layer on the substrate by electroplating;

[0042] Etching the substrate having the hydrogen evolution active layer to form a microchannel structure on the surface of the hydrogen evolution active layer to obtain an alkaline hydrogen production electrode;

[0043] The electroplating solution used in the electroplating comprises a main active ingredient and a secondary active ingredient, wherein the main active ingredient comprises a nickel salt, and the secondary active ingredient comprises at least one of an iron salt, a cobalt salt, a copper salt, a manganese salt, and a molybdenum salt. The main active ingredient can make the coating have better alkali corrosion resistance, and the secondary active ingredient can improve the hydrogen evolution performance of the coating, and the combination of the two can ensure that the coating can efficiently and stably precipitate hydrogen in an alkali solution.

[0044] The present application prepares gas-liquid flow channels on the electrode surface through electrolytic etching technology, which can increase the specific surface area and the number of active sites of the electrode, while reducing concentration polarization, improving electrode efficiency, and ultimately reducing the energy consumption of water electrolysis and hydrogen production costs.

[0045] Specifically, the thickness of the hydrogen evolution active layer prepared in the present application is relatively thick, the etching time is short, the etching only occurs on the surface of the hydrogen evolution active layer, which is far away from the substrate, and the transition area between the substrate and the hydrogen evolution active layer will not be etched, which will not affect the strength of its binding force, and can ensure that the electrode can operate stably for a long time. Moreover, the etching action starts from the surface of the hydrogen evolution active layer and gradually moves to the inside of the electrode, exposing the active sites while generating a large number of microchannels, which increases the electrode activity and reduces the influence of concentration polarization.

[0046] In some embodiments, the nickel salt includes nickel sulfate, the iron salt includes iron sulfate, the cobalt salt includes cobalt sulfate, the copper salt includes copper sulfate, the manganese salt includes manganese sulfate, and the molybdenum salt includes molybdenum sulfate.

[0047] According to an embodiment of the present application, the substrate includes any one of a nickel mesh, a nickel foam, a nickel felt, and a carbon felt, the mesh number of the nickel mesh is 20-200 meshes, the porosity of the nickel foam is 70%-99%, the thickness of the nickel felt is 0.5-5 mm, and the density of the carbon felt is 0.1-0.5 g / cm 3 ;

[0048] For example, the mesh number of the nickel mesh can be 20 mesh, 30 mesh, 40 mesh, 50 mesh, 60 mesh, 70 mesh, 80 mesh, 90 mesh, 100 mesh, 110 mesh, 120 mesh, 130 mesh, 140 mesh, 150 mesh, 160 mesh, 170 mesh, 180 mesh, 190 mesh, 200 mesh or any value between 20-200 mesh, and the mesh number of the nickel mesh is preferably 30-60 mesh. The porosity of the nickel foam can be 70%, 75%, 80%, 85%, 90%, 99% or any value between 70%-99%, and the porosity of the nickel foam is preferably 90%-96%. The thickness of the nickel felt can be 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm or any value between 0.5-5mm, and the thickness of the nickel felt is preferably 1-3mm. The density of the carbon felt can be 0.1g / cm 3 , 0.2g / cm3, 0.3g / cm 3 , 0.4g / cm 3 , 0.5g / cm 3 Or 0.1-0.5g / cm 3 The density of carbon felt is preferably 0.2-0.4 g / cm 3 .

[0049] And / or, the electroplating anode includes any one of a titanium plate and a graphite plate;

[0050] And / or, the molar ratio of the metal element in the main active ingredient to the metal element in the secondary active ingredient is 5:1 to 5:4; when the main active ingredient and the secondary active ingredient are within the above ratio range, the product can be highly active and highly stable in alkaline solution. If the content of the main active ingredient is too little, the electrode will have poor alkali corrosion resistance and poor stability; if the content of the main active ingredient is too much, the content of the secondary active ingredient is relatively small, which will reduce the hydrogen evolution performance of the electrode.

[0051] For example, the molar ratio of the metal element in the primary active component to the metal element in the secondary active component may be 5:1, 5:2, 5:3, 5:4, or any value between 5:1 and 5:4.

[0052] And / or, the concentration of the electroplating solution is 0.1-2 mol / L;

[0053] For example, the concentration of the plating solution may be 0.1 mol / L, 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L or any value between 0.1-2 mol / L, and the concentration of the plating solution is preferably 0.5-1.5 mol / L.

[0054] And / or, the electroplating temperature is 20-50°C.

[0055] The electroplating temperature may be 20°C, 30°C, 40°C, 50°C or any value between 20-50°C, and the electroplating temperature is preferably 30-40°C.

[0056] According to an embodiment of the present application, the pH value of the electroplating solution is 2-6. When the pH value of the electroplating solution is within the above range, the active ingredient can be smoothly and effectively electroplated onto the substrate, ensuring the smooth progress of the electroplating process. If the pH value of the electroplating solution is too low, it will hinder the effective electroplating of the active ingredient; if the pH value of the electroplating solution is too high, it may cause the active ingredient to precipitate.

[0057] For example, the pH value of the electroplating solution may be 2, 3, 4, 5, 6, or any value between 2 and 6. The pH value of the electroplating solution is preferably 3-5.

[0058] According to the embodiment of the present application, the electroplating current is 0.01-1A / cm 2 When the electroplating current is within the above range, a uniform and dense coating can be formed within a reasonable time, which can ensure production efficiency and help extend the service life of the electrode. If the electroplating current is too small, the time required for electroplating will be extended, affecting production efficiency; if the electroplating current is too large, it may cause the coating to burn and damage the coating quality. For example, the electroplating current can be 0.01A / cm2 , 0.05A / cm 2 , 0.1A / cm 2 , 0.5A / cm 2 , 1A / cm 2 Or 0.01-1A / cm 2 The electroplating current is preferably 0.05-0.5A / cm 2 .

[0059] According to an embodiment of the present application, the electroplating time is 10 min-5 h. When the electroplating time is within the above range, the electroplating process can be fully carried out, and the coating can have sufficient thickness and density, which is beneficial to improving the performance of the electrode. If the electroplating time is too short, the thickness of the coating may be too small and the coverage may be incomplete, thereby affecting the performance of the electrode; if the electroplating time is too long, the coating may be too thick, increasing material consumption and production costs.

[0060] For example, the electroplating time can be 10 min, 30 min, 1 h, 2 h, 3 h, 4 h, 5 h or any value between 10 min and 5 h, and the electroplating time is preferably 30 min to 3 h.

[0061] According to an embodiment of the present application, the etching method includes any one of electrolysis, chemical etching, plasma etching, and laser etching.

[0062] For example, chemical etching can use an acid or alkali solution with a concentration of 0.5-5 mol / L (preferably 1-3 mol / L), at a temperature of 30-80°C (preferably 40-60°C), and the etching time is 1-10h (preferably 3-7h). Plasma etching can set the plasma power to 100-1000W (preferably 300-700W), and the etching time is 5-60min (preferably 10-30min). Laser etching can use a laser with a wavelength of 100-1000nm (preferably 300-700nm), and the laser power density is 10-10W / cm 2 (Preferably 3×10-7×10W / cm 2 ), the scanning speed is 1-10mm / s (preferably 3-7mm / s).

[0063] According to an embodiment of the present application, when the substrate having the hydrogen evolution active layer is etched by electrolysis, the cathode of the electrolysis is the substrate having the hydrogen evolution active layer, the anode of the electrolysis is any one of a titanium plate and a graphite plate, and the electrolyte of the electrolysis includes a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 1%-75%;

[0064] For example, the mass concentration of the sulfuric acid solution can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or any value between 1% and 75%, and the mass concentration of the sulfuric acid solution is preferably 10%-50%.

[0065] And / or, the electrolysis temperature is 20-60°C.

[0066] For example, the electrolysis temperature may be 20°C, 30°C, 40°C, 50°C, 60°C or any value between 20-60°C, and the electrolysis temperature is preferably 30-50°C.

[0067] According to the embodiment of the present application, the current density of the electrolysis is 0.5-2A / cm 2 When the electrolysis current density is within the above range, the electrolysis process can be carried out at a relatively high speed, shortening the electrolysis time, thereby improving production efficiency; at the same time, the processing quality can be ensured. If the electrolysis current density is too small, the electrolysis time will be too long, affecting production efficiency; if the electrolysis current density is too large, the processing accuracy will be difficult to control and it is easy to over-etch.

[0068] For example, the current density of electrolysis can be 0.5A / cm 2 , 1A / cm 2 , 1.5A / cm 2 , 2A / cm 2 Or 0.5-2A / cm 2 The current density of electrolysis is preferably 1-1.5 A / cm 2 .

[0069] During the electrolytic etching process, hydrogen is generated at the active sites on the cathode surface. The hydrogen is adsorbed on the surface to protect it from corrosion by sulfuric acid, while the less active or inactive surface areas are etched by sulfuric acid, increasing the number of active sites exposed on the electrode surface and forming a large number of corrosion points, ultimately forming channels for gas-liquid circulation.

[0070] According to the embodiments of the present application, the electrolysis process adopts a constant current mode, and the voltage changes are detected in real time. During the etching process, as the active sites continue to increase, the voltage gradually decreases. When it is observed that the voltage remains stable within 5-15 minutes and no longer continues to decrease (that is, the voltage drops to the lowest point and remains stable within 5-15 minutes), the electrolysis process is stopped.

[0071] The hydrogen evolution activity of the electrode is affected by two factors: one is the active sites on the electrode surface, and the other is the concentration of the electrolyte. At the beginning of etching, the number of active sites on the electrode surface gradually increases, the activity increases, the required overpotential decreases, and the voltage gradually decreases. The voltage drops to the lowest point, indicating that there are enough active sites on the electrode surface, and the hydrogen evolution control step becomes concentration polarization, that is, the speed at which ions in the electrolyte reach the electrode surface limits the reaction. Maintaining the lowest voltage for a few minutes is to ensure the stability of the active sites on the electrode surface. At the same time, the control time should not be too long to ensure the stability of the electrode structure.

[0072] The present application also provides an alkaline hydrogen production electrode, which is prepared by the preparation method of the alkaline hydrogen production electrode described above.

[0073] The present application also provides a water electrolysis hydrogen production device, including an alkaline hydrogen production electrode prepared by the preparation method of the alkaline hydrogen production electrode described above or including the alkaline hydrogen production electrode described above.

[0074] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0075] 1. Preparation of alkaline hydrogen production electrode

[0076] Example 1

[0077] Embodiment 1 provides an alkaline hydrogen production electrode, and the preparation method thereof comprises:

[0078] (1) Select plating solution

[0079] Nickel sulfate was selected as the main active ingredient, and iron sulfate and cobalt sulfate were added as secondary active ingredients. Accurately weigh appropriate amounts of nickel sulfate, iron sulfate, and cobalt sulfate, mix them according to the molar ratio of nickel: iron: cobalt = 7:2:1, and add appropriate amounts of deionized water to prepare a plating solution with a total concentration of 1 mol / L. During the preparation process, a precision pH meter was used to monitor the pH value of the solution in real time, and the pH value of the solution was stabilized at 4 by adding an appropriate amount of acid-base regulator.

[0080] (2) Preparation of hydrogen evolution active layer: The hydrogen evolution active layer is formed on the substrate by electroplating.

[0081] Specifically, nickel foam with a porosity of 85% was selected as the substrate. During the electroplating process, the temperature was strictly controlled at 35°C, and the titanium plate was used as the anode to form a stable electroplating environment. The electroplating current was set to 0.3A / cm 2, and electroplating continued for 2 h.

[0082] (3) Electrolytic etching: The substrate having the hydrogen evolution active layer is etched to form a microchannel structure on the surface of the hydrogen evolution active layer, thereby obtaining an alkaline hydrogen production electrode.

[0083] The substrate with hydrogen evolution active layer prepared in step (2) is used as cathode, and the graphite plate is selected as anode, and the two are accurately installed in the corresponding positions of the electrolysis device. A sulfuric acid solution with a mass concentration of 30% is injected into the electrolysis device as the electrolyte. Under the condition of an ambient temperature of 40°C, the entire electrolysis device is assembled to ensure that the device is well sealed and the electrode connection is stable. Subsequently, the etching current density is accurately set to 1.2A / cm 2 , start the electrolytic etching process. During the etching process, use a high-precision voltmeter to monitor the voltage change in real time. When the voltage drops to the lowest point and remains stable for 10 minutes, stop the electrolytic etching operation.

[0084] The optical microscope image of the electrode prepared in Example 1 is as follows: Figure 1 shown.

[0085] Example 2

[0086] Embodiment 2 provides an alkaline hydrogen production electrode, and the preparation method thereof comprises:

[0087] (1) Select plating solution

[0088] Nickel sulfate was selected as the main active ingredient, and copper sulfate and manganese sulfate were added as secondary active ingredients. Nickel sulfate, copper sulfate, and manganese sulfate were accurately weighed according to the molar ratio of nickel: copper: manganese = 6:3:1, and added into a container with sufficient deionized water to prepare a plating solution with a total concentration of 0.5 mol / L. During this period, a precision pH meter was used for continuous monitoring, and an appropriate amount of hydrochloric acid was added to accurately adjust the pH value of the solution to 3.

[0089] (2) Preparation of hydrogen evolution active layer: The hydrogen evolution active layer is formed on the substrate by electroplating.

[0090] Specifically, a nickel mesh with a mesh size of 30 was selected as the substrate, the temperature was controlled at 30°C during electroplating, and the graphite plate was used as the anode. The electroplating current was set to 0.05 A / cm 2 , start electroplating, duration 30min.

[0091] (3) Electrolytic etching: The substrate having the hydrogen evolution active layer is etched to form a microchannel structure on the surface of the hydrogen evolution active layer, thereby obtaining an alkaline hydrogen production electrode.

[0092] The substrate with hydrogen evolution active layer prepared in step (2) was used as cathode and the titanium plate as anode, and they were installed in the electrolysis device. A sulfuric acid solution with a mass concentration of 10% was injected as electrolyte, and the device was assembled at 30°C to ensure the sealing and correct electrode connection. The etching current density was set to 1A / cm 2 , start electrolytic etching, and monitor the voltage with a high-precision voltmeter. When the voltage drops to the lowest point and stabilizes for 8 minutes, end the etching.

[0093] Example 3

[0094] Embodiment 3 provides an alkaline hydrogen production electrode, and the preparation method thereof comprises:

[0095] (1) Select plating solution

[0096] Nickel sulfate was selected as the main active ingredient, and molybdenum sulfate and cobalt sulfate were added as secondary active ingredients. The nickel sulfate, molybdenum sulfate and cobalt sulfate were accurately mixed according to the molar ratio of nickel: molybdenum: cobalt = 8:1:1. Nickel sulfate, molybdenum sulfate and cobalt sulfate were weighed and added with deionized water to form a plating solution with a total concentration of 1.5 mol / L. The solution was monitored with a precision pH meter and the pH value of the solution was adjusted to 5 by adding an acid regulator.

[0097] (2) Preparation of hydrogen evolution active layer: The hydrogen evolution active layer is formed on the substrate by electroplating.

[0098] Specifically, a nickel felt with a thickness of 1 mm was selected as the substrate, the electroplating temperature was controlled at 40°C, a titanium plate was used as the anode, and the electroplating current was set to 0.5 A / cm 2 , electroplating for 3h.

[0099] (3) Electrolytic etching: The substrate having the hydrogen evolution active layer is etched to form a microchannel structure on the surface of the hydrogen evolution active layer, thereby obtaining an alkaline hydrogen production electrode.

[0100] The substrate with hydrogen evolution active layer prepared in step (2) was used as cathode and the graphite plate was used as anode in an electrolysis device, and a sulfuric acid solution with a mass concentration of 50% was injected. The device was assembled at an ambient temperature of 50°C and the etching current density was set to 1.5 A / cm 2 , start the electrolytic etching process and monitor the voltage. When the voltage drops to the lowest point and remains stable for 12 minutes, stop the electrolytic etching operation.

[0101] Example 4

[0102] Embodiment 4 provides an alkaline hydrogen production electrode, and the preparation method thereof comprises:

[0103] (1) Select plating solution

[0104] The other parameters of step (1) are the same as those of Example 1. The difference from Example 1 is that the pH value of the solution is not adjusted in Example 4, and the measured pH value of the solution in Example 4 is 7.

[0105] (2) Preparation of hydrogen evolution active layer: The hydrogen evolution active layer is formed on the substrate by electroplating.

[0106] The parameters of step (2) are the same as those in Example 1.

[0107] (3) Electrolytic etching: The substrate having the hydrogen evolution active layer is etched to form a microchannel structure on the surface of the hydrogen evolution active layer, thereby obtaining an alkaline hydrogen production electrode.

[0108] The other parameters of step (3) are the same as those of Example 1. The difference from Example 1 is that no matter how the voltage changes, the electrolytic etching operation of Example 4 is stopped when the etching time reaches 5 minutes.

[0109] Example 5

[0110] Embodiment 5 provides an alkaline hydrogen production electrode, and the preparation method thereof comprises:

[0111] (1) Select plating solution

[0112] The composition of the plating solution is the same as that of Example 2.

[0113] (2) Preparation of hydrogen evolution active layer: The hydrogen evolution active layer is formed on the substrate by electroplating.

[0114] The other parameters of step (2) are the same as those of Example 2, except that the electroplating current in Example 5 is 0.01 A / cm 2 .

[0115] (3) Electrolytic etching: The substrate having the hydrogen evolution active layer is etched to form a microchannel structure on the surface of the hydrogen evolution active layer, thereby obtaining an alkaline hydrogen production electrode.

[0116] The other parameters of step (3) are the same as those of Example 2, except that the etching current density in Example 5 is 0.3 A / cm 2 , electrolytic etching at 40°C.

[0117] Example 6

[0118] Embodiment 6 provides an alkaline hydrogen production electrode, and the preparation method thereof comprises:

[0119] (1) Select plating solution

[0120] The composition of the plating solution is the same as that of Example 3.

[0121] (2) Preparation of hydrogen evolution active layer: The hydrogen evolution active layer is formed on the substrate by electroplating.

[0122] The other parameters of step (2) are the same as those of Example 3, except that the electroplating time of Example 6 is shortened to 1 hour.

[0123] (3) Electrolytic etching: The substrate having the hydrogen evolution active layer is etched to form a microchannel structure on the surface of the hydrogen evolution active layer, thereby obtaining an alkaline hydrogen production electrode.

[0124] The other parameters of step (3) are the same as those of Example 3, except that the etching current density of Example 6 is 2.5 A / cm 2 .

[0125] Comparative Example 1

[0126] An alkaline hydrogen production electrode was prepared by referring to the method of Example 1. The other steps were the same as those of Example 1, except that step (3) was omitted in Example 1, i.e., electrolytic etching was not performed in the method of Example 1, and the product prepared in step (2) was directly used as the alkaline hydrogen production electrode.

[0127] The optical microscope image of the electrode prepared in Comparative Example 1 is as follows: Figure 2 shown.

[0128] Comparative Example 2

[0129] An alkaline hydrogen-producing electrode was prepared by referring to the method of Example 1. The other steps were the same as those of Example 1, except that the electroplating solution of Comparative Example 2 contained only nickel sulfate, and the concentration of nickel sulfate was 1 mol / L.

[0130] Comparative Example 3

[0131] An alkaline hydrogen-producing electrode was prepared by referring to the method of Example 1. The other steps were the same as those of Example 1, except that the electroplating solution in Comparative Example 3 contained only ferrous sulfate and cobalt sulfate, the total concentration of the electroplating solution was 1 mol / L, and the molar ratio of iron to cobalt in the electroplating solution was 2:1.

[0132] 2. Electrode performance test

[0133] Catalytic activity test: A three-electrode system was built, and the electrodes prepared in Examples 1-6 and Comparative Examples 1-3 were used as working electrodes, platinum sheets with stable performance and high purity were selected as counter electrodes, and saturated calomel electrodes were used as reference electrodes. The three-electrode system was placed in a potassium hydroxide solution with a constant temperature and a concentration of 1 mol / L. A linear sweep voltammetry test was performed using a high-precision electrochemical workstation, and the scan rate was set to 5 mV / s to ensure the accuracy of the test data. At a current density of 100 mA / cm 2 When , the overpotentials of the electrodes of Examples 1-6 and Comparative Examples 1-3 were tested.

[0134] Stability test: In a small alkaline electrolyzer test device, set the constant current density to 500mA / cm 2, and a long-term electrolysis test was started under this condition. Test conditions: 30wt% KOH electrolyte, stable at 80°C, PPS diaphragm, and nickel mesh as the counter electrode. After 1500 hours of continuous operation, the catalytic performance of the electrodes of Examples 1-6 and Comparative Examples 1-3 was regularly monitored using advanced electrochemical analysis techniques.

[0135] The performance test results of the electrodes of Examples 1-6 and Comparative Examples 1-3 are shown in Table 1.

[0136] Table 1 Performance test results of electrodes of Examples 1-6 and Comparative Examples 1-3

[0137]

[0138]

[0139] Compared with Examples 1-6, the electrodes of Comparative Examples 1-3 have higher overpotentials or higher voltage increases, indicating that only the alkaline hydrogen production electrode prepared by the method of the present application has both high catalytic activity and excellent stability.

[0140] The overpotential of the traditional alkaline hydrogen production electrode is about 150mV, and the overpotentials of Examples 1-6 are all lower than 150mV, indicating that the electrode prepared in the present application has excellent catalytic activity and can drive the hydrogen evolution reaction at a lower overpotential, effectively improving the energy utilization efficiency. In addition, the electrode in the present application also has excellent stability during long-term operation and can maintain good hydrogen evolution performance, providing a strong guarantee for long-term stable hydrogen production in practical applications.

[0141] Compared with Examples 4-6, Examples 1-3 have lower overpotential and lower voltage rise, indicating that the pH value of the electroplating solution is preferably 2-6, and the current density of the electrolysis is preferably 0.5-2 A / cm 2 The electrolysis process preferably adopts a constant current mode and the electrolysis is stopped when the voltage remains stable within 5-15 minutes and no longer decreases. Under the above conditions, the prepared alkaline hydrogen-producing electrode can have a lower overpotential and a smaller voltage increase during a long electrolysis process, indicating that under the above conditions, the prepared alkaline hydrogen-producing electrode can have higher catalytic activity and better stability.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0143] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing an alkaline hydrogen production electrode, characterized in that: include: Forming a hydrogen evolution active layer on the substrate by electroplating; Etching the substrate having the hydrogen evolution active layer to form a microchannel structure on the surface of the hydrogen evolution active layer to obtain an alkaline hydrogen production electrode; The electroplating solution used in the electroplating comprises a main active ingredient and a secondary active ingredient, wherein the main active ingredient comprises a nickel salt, and the secondary active ingredient comprises at least one of an iron salt, a cobalt salt, a copper salt, a manganese salt, and a molybdenum salt.

2. The method for preparing an alkaline hydrogen production electrode according to claim 1, characterized in that: The substrate comprises any one of nickel mesh, nickel foam, nickel felt and carbon felt. The mesh number of the nickel mesh is 20-200 meshes, the porosity of the nickel foam is 70%-99%, the thickness of the nickel felt is 0.5-5 mm, and the density of the carbon felt is 0.1-0.5 g / cm 3 ; And / or, the electroplating anode includes any one of a titanium plate and a graphite plate; and / or, the molar ratio of the metal element in the primary active ingredient to the metal element in the secondary active ingredient is 5:1 to 5:4; And / or, the concentration of the electroplating solution is 0.1-2 mol / L; And / or, the electroplating temperature is 20-50°C.

3. The method for preparing an alkaline hydrogen production electrode according to claim 1, characterized in that: The pH value of the electroplating solution is 2-6.

4. The method for preparing an alkaline hydrogen production electrode according to any one of claims 1 to 3, characterized in that: The electroplating current is 0.01-1A / cm 2 ; And / or, the electroplating time is 10 min-5 h.

5. The method for preparing an alkaline hydrogen production electrode according to claim 1, characterized in that: The etching method includes any one of electrolysis, chemical etching, plasma etching and laser etching.

6. The method for preparing an alkaline hydrogen production electrode according to claim 5, characterized in that: When the substrate having the hydrogen evolution active layer is etched by electrolysis, the cathode of the electrolysis is the substrate having the hydrogen evolution active layer, the anode of the electrolysis is any one of a titanium plate and a graphite plate, the electrolyte of the electrolysis includes a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 1%-75%; And / or, the electrolysis temperature is 20-60°C.

7. The method for preparing an alkaline hydrogen production electrode according to claim 5, characterized in that: The current density of the electrolysis is 0.5-2A / cm 2 .

8. The method for preparing an alkaline hydrogen production electrode according to any one of claims 5 to 7, characterized in that: The electrolysis process adopts a constant current mode, and the voltage change is detected in real time. When it is observed that the voltage remains stable within 5-15 minutes and does not continue to decrease, the electrolysis process is stopped.

9. An alkaline hydrogen production electrode, characterized in that: The alkaline hydrogen production electrode is prepared by the preparation method of the alkaline hydrogen production electrode according to any one of claims 1 to 8.

10. A hydrogen production device by electrolysis of water, characterized in that: An alkaline hydrogen-producing electrode prepared by the method for preparing an alkaline hydrogen-producing electrode according to any one of claims 1 to 8 or an alkaline hydrogen-producing electrode according to claim 9.

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