High-activity large-size water electrolysis hydrogen evolution electrode as well as preparation method and application thereof

Abstract

The invention discloses a high-activity large-size water electrolysis hydrogen evolution electrode, and relates to the technical field of clean energy materials, the electrode comprises a foamed nickel substrate and a nickel oxide micro-nano structure layer generated in situ on the skeleton surface of the foamed nickel substrate through pulse laser ablation; according to the high-activity large-size water electrolysis hydrogen evolution electrode, the nickel oxide micro-nano structure layer is generated on the skeleton surface of the foamed nickel substrate in situ through ablation of the pulse laser, so that the nickel oxide micro-nano structure layer is firmly connected with the foamed nickel substrate, and the electron conduction efficiency and the structural stability can be improved; the stability of the electrochemical activity is further improved; meanwhile, the nickel oxide micro-nano structure layer shows high hydrogen evolution catalytic activity, low overpotential, high electrochemical activity and excellent long-term stability in alkaline electrolyte.

Description

Technical Field

[0001] This invention relates to the field of clean energy materials technology, specifically to a highly active, large-size electrolytic water hydrogen evolution electrode, its preparation method, and its application. Background Technology

[0002] Hydrogen production through water electrolysis, a green hydrogen production technology that can be directly coupled with renewable energy sources (such as photovoltaics and wind power), enables the efficient conversion of "green electricity" into "green hydrogen." Guided by the "dual carbon" goal, it has become one of the core technological pathways supporting energy structure transformation, industrial decarbonization, and zero emissions in the transportation sector. Compared to hydrogen production from fossil fuels, water electrolysis avoids carbon emissions, and the produced hydrogen has a purity of over 99.9%, making it widely applicable in high-end fields such as fuel cells, chemical synthesis, and metallurgy. Its core reactions involve the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode. The kinetic rate of HER directly determines the overall energy conversion efficiency of the electrolyzer; therefore, developing high-performance HER catalysts is crucial for reducing the cost of water electrolysis for hydrogen production and promoting the large-scale application of the technology.

[0003] Currently, the industry and academia generally recognize Pt as the best-performing electrocatalyst for hydrogen electrolysis (HER), such as Pt / C catalysts. These catalysts exhibit low overpotentials (as low as 10-30 mV) under acidic conditions, low charge transfer resistance, and rapid catalytic kinetics. However, Pt's crustal abundance is only 0.005 ppm, making its global reserves scarce, and its price exceeds 2000 yuan per gram. This results in Pt / C catalysts accounting for 30%-40% of the total cost of an electrolyzer, severely hindering the commercialization of water electrolysis for hydrogen production. Furthermore, precious metal catalysts are prone to aggregation, dissolution, and loss during long-term electrolysis, further reducing electrode lifespan and economic efficiency, making it difficult to meet the stringent requirements of continuous operation for thousands of hours in large-scale industrial electrolyzers. Therefore, developing low-cost, highly active, and long-term stable non-precious metal HER catalysts has become a core issue for breakthroughs in water electrolysis for hydrogen production technology.

[0004] Among numerous non-noble metal catalysts, Ni-based oxides stand out as one of the most promising candidate systems due to their abundant resources, tunable electronic structure, and adsorption energy characteristics well-suited for the HER reaction. Studies have shown that the catalytic activity of Ni-based oxides originates from the Ni formed on their surface. 2+ / Ni 3+ Redox pairs can be further optimized for H by controlling their crystal structure, morphology, or electronic states. + The adsorption-desorption equilibrium is close to the performance level of noble metal catalysts. In recent years, Ni-based catalysts have shown promising application prospects in alkaline water electrolysis. The overpotential of some modified Ni-based catalysts can be reduced to 50-80mV, showing potential to replace noble metals.

[0005] However, existing Ni-based catalyst preparation technologies still face numerous unresolved issues. On one hand, traditional methods often rely on high-temperature annealing, prolonged hydrothermal reactions, or solvothermal synthesis processes. These processes not only consume significant amounts of energy but also suffer from long reaction cycles and low production efficiency, hindering large-scale, low-cost production. More importantly, the preparation of some high-performance Ni-based catalysts requires the use of toxic precursors such as thioacetamide and phosphine. These substances are volatile and highly corrosive, posing a threat to operator health and causing severe environmental pollution, contradicting the principles of green manufacturing. On the other hand, existing Ni-based catalysts are mostly in powder form, requiring the addition of polymer binders such as Nafion and polytetrafluoroethylene (PTFE) during electrode preparation to fix them onto current collectors such as Ti mesh and carbon paper. The introduction of binders not only physically covers some catalytic active sites but also increases the electrode interfacial resistance, hindering charge transfer and mass transport. Furthermore, the interfacial bonding between the binder and catalyst particles / current collectors is weak, making them prone to peeling and detachment during long-term electrolysis, leading to catalyst loss and rapid electrode performance degradation, severely impacting the long-term stability of the electrolyzer. Summary of the Invention

[0006] This invention aims to solve the problems of existing Ni-based catalysts, such as complex processes, high energy consumption, environmental unfriendliness, low electrochemical activity, and poor stability.

[0007] To address the aforementioned issues, this invention provides a highly active, large-size electrolytic water hydrogen evolution electrode, comprising a nickel foam substrate and a nickel oxide micro / nano structure layer generated in situ on the skeleton surface of the nickel foam substrate by pulsed laser ablation.

[0008] The present invention provides a highly active, large-size electrolytic water hydrogen evolution electrode, which, compared with the prior art, has, but is not limited to, the following beneficial effects: In the high-activity, large-size electrolytic hydrogen evolution electrode of this invention, a nickel oxide micro / nano structure layer is generated in situ on the surface of the nickel foam substrate skeleton through pulsed laser ablation. This allows the nickel oxide micro / nano structure layer to be firmly connected to the nickel foam substrate, which can improve electron conduction efficiency and structural stability, thereby improving the stability of electrochemical activity. At the same time, the nickel oxide micro / nano structure layer exhibits high hydrogen evolution catalytic activity, low overpotential, high electrochemical activity, and excellent long-term stability in alkaline electrolyte.

[0009] Furthermore, the main component of the nickel oxide micro / nano structure layer is NiO.

[0010] Specifically, NiO, as a typical Ni-based oxide, possesses an electronic structure and surface active sites adapted to the hydrogen evolution reaction in alkaline water electrolysis. As a major component, it ensures the catalytic selectivity of the active layer, avoids interference from other oxide impurities on the hydrogen evolution reaction pathway, further reduces overpotential, and improves catalytic efficiency. NiO is made from abundant and plentiful nickel resources, significantly reducing procurement costs compared to precious metal oxides (such as Pt / C). Moreover, its preparation process does not require complex element doping or modification, simplifying the process while further controlling costs, thus providing feasibility for large-scale industrial applications. Furthermore, NiO is chemically stable and does not easily dissolve or undergo redox deterioration in alkaline electrolytes. Its in-situ bonding structure with the nickel foam substrate forms a synergistic stabilizing effect, ensuring the integrity of the active components in the electrode during long-term hydrogen evolution reactions and extending its service life.

[0011] Furthermore, the nickel oxide micro / nano structure layer has a porous and rough microstructure.

[0012] Specifically, the porous and rough morphology significantly increases the specific surface area of ​​the micro / nano structure layer (compared to the smooth surface of nickel foam substrates), maximizing the exposure of NiO's catalytic active sites and solving the problem of masked active sites in traditional catalysts. This provides ample reaction sites for the hydrogen evolution reaction at high current densities. The porous structure forms continuous electrolyte diffusion channels, accelerating the contact between the alkaline electrolyte and the active sites, while also facilitating the formation of hydrogen evolution reaction sites. Rapid bubble escape prevents blockage of active sites caused by bubble adhesion, reduces mass transfer resistance, and improves reaction kinetic rate (manifested as a decrease in Tafel slope). Moreover, the in-situ constructed NiO micro / nano structure layer endows the active layer with a certain mechanical toughness, which can buffer stress impact during laser processing, ultrasonic cleaning, and long-term electrolytic reaction, reduce structural damage, and further enhance the long-term stability of the electrode.

[0013] This invention also discloses a method for preparing a highly active, large-size water electrolysis hydrogen evolution electrode, used to prepare the highly active, large-size water electrolysis hydrogen evolution electrode as described above, comprising the following steps: Step 1: Pre-treat the nickel foam substrate sequentially; Step 2: Perform a single line scan on the cleaned nickel foam substrate using a pulsed laser at a scanning speed of 10-50 μm / s.

[0014] The present invention provides a method for preparing a highly active, large-size electrolytic hydrogen evolution electrode for water electrolysis, which, compared with the prior art, has the following beneficial effects, but is not limited to: Compared to the complex processes of traditional Ni-based catalysts, such as high-temperature annealing and prolonged hydrothermal reactions, this method only requires two core operations: pretreatment and a single linear scan. The process is simplified and less time-consuming. Furthermore, it eliminates the need for toxic precursors or highly corrosive reagents, significantly reducing energy consumption (laser processing does not require a high-temperature environment), aligning with green manufacturing principles. The defined scanning speed (10-50 μm / s) represents an optimized range after numerous experiments. Too low a power output fails to effectively generate the micro / nano structure layer, while too high a power output easily ablates and damages the foamed nickel substrate. Excessive scanning speed leads to discontinuous active layers, while excessively slow speeds reduce efficiency. The fabrication efficiency, within this parameter range, ensures the acquisition of a uniform and complete nickel oxide micro / nano structure layer while achieving high-efficiency fabrication. The single-line-scan laser processing method offers high controllability, precisely replicating the electrode's microstructure and performance. This avoids the significant batch-to-batch variations in active layer thickness and morphology found in traditional processes, ensuring uniform electrode performance in mass production and meeting the stability requirements of industrial applications. Furthermore, laser line scanning can flexibly adapt to nickel foam substrates of different sizes, solving the pain point of large-scale fabrication of traditional micro / nano structure electrodes and providing technical support for the production of large-size industrial-grade electrodes.

[0015] Further, in step 1, the pretreatment method is as follows: the nickel foam substrate is cut into the required size and ultrasonically cleaned in acetone, ethanol and deionized water in sequence, and then dried for later use.

[0016] Specifically, the surface of the nickel foam substrate is usually covered with grease, oxide film, and organic impurities. Acetone can efficiently dissolve grease, ethanol can remove residual organic matter, and deionized water rinsing can remove salt impurities and solvent residues. Three-step ultrasonic cleaning ensures thorough removal of impurities, preventing them from obstructing laser action sites or affecting the adhesion between the micro / nano structure layer and the nickel foam substrate. After cleaning and removing the oxide film, the active nickel metal on the surface of the nickel foam substrate is exposed, providing sufficient reaction sites for the in-situ oxidation reaction (generating NiO) during pulsed laser ablation. This ensures uniform growth of the nickel oxide micro / nano structure layer and avoids local defects in the active layer caused by substrate impurities. Drying removes residual moisture from the substrate surface, preventing water from generating bubbles and splashing during laser processing, and preventing problems such as uneven porosity and inconsistent thickness in the micro / nano structure layer. At the same time, a clean and dry substrate can reduce electrode performance degradation caused by impurities during subsequent use, improving batch stability of the product.

[0017] Furthermore, in step 2, the pulsed laser is an ultraviolet laser with a wavelength of 532 μm.

[0018] Specifically, ultraviolet lasers have high photon energy and a short wavelength (532µm). After focusing, the spot size is small and the energy density is concentrated, allowing for precise application to the skeletal surface of the nickel foam substrate. This enables localized selective ablation and in-situ oxidation, avoiding excessive damage to the substrate or uneven growth of the active layer caused by laser energy dispersion. The 532µm wavelength of the ultraviolet laser is highly compatible with the optical absorption characteristics of nickel, efficiently exciting nickel atoms on the surface of the nickel foam to react with oxygen in the air, rapidly generating a NiO micro / nano structure layer and shortening the reaction time. At the same time, the short pulse characteristics of the ultraviolet laser reduce the impact of thermal diffusion on the substrate, preventing deformation or performance degradation of the nickel foam substrate.

[0019] Furthermore, in step 2, the pulse repetition frequency of the pulsed laser is 5-20Hz, the pulse width is 5-10ns, the average output energy per pulse is 50-300mJ, and the distance from the laser spot to the surface of the nickel foam substrate is 10-20cm.

[0020] Specifically, the pulse repetition frequency (5-20Hz) determines the number of laser interactions per unit area, and the pulse width (5-10ns) is on the nanosecond scale, which ensures sufficient energy to trigger the oxidation reaction while avoiding thermal accumulation damage to the substrate caused by long pulses; the average output energy per pulse (50-300mJ) ensures that the generated NiO micro / nano structure layer has a moderate thickness. If the energy is too low, the active layer will be too thin and there will be insufficient catalytic sites, while if it is too high, the active layer will be too thick and electron conduction will be blocked; the spot distance (10-20cm) ensures the laser focusing accuracy and avoids the processing efficiency being reduced due to an excessively large spot.

[0021] Furthermore, it also includes the following step 3: Step 3: Perform ultrasonic cleaning and drying on the laser-scanned product.

[0022] Specifically, during laser ablation, a small number of loose nickel oxide deposits are generated and adhere to the surface of the active layer. Ultrasonic cleaning can remove them by high-frequency vibration.

[0023] Furthermore, the ultrasonic cleaning method is as follows: the product after laser scanning is placed in anhydrous ethanol for cleaning for 2 minutes.

[0024] Specifically, anhydrous ethanol does not chemically react with NiO and nickel foam substrate, thus avoiding the corrosion and dissolution problems of the active layer caused by the use of water or other solvents; the 2-minute time can fully remove residual particles, while avoiding the collapse of the micro-nano structure layer pores caused by excessive time, ensuring that the micro-nano structure layer still maintains a porous and rough excellent morphology after cleaning, without affecting the specific surface area and catalytic site exposure.

[0025] This invention also discloses the application of a highly active, large-size water electrolysis hydrogen evolution electrode as described above, for use in alkaline water electrolysis hydrogen evolution reactions.

[0026] The application of a highly active, large-size hydrogen evolution electrode for water electrolysis provided by this invention has, but is not limited to, the following beneficial effects compared to existing technologies: The nickel oxide micro / nano structure layer of this electrode exhibits excellent catalytic activity and stability in alkaline electrolytes, with low overpotential and fast reaction kinetics. Compared to neutral or acidic electrolytes, it can more fully utilize the electrode's performance advantages. Alkaline water electrolysis for hydrogen production is currently the mainstream technology for industrial-scale hydrogen production. This electrode can directly replace inefficient or precious metal electrodes in traditional alkaline electrolyzers without requiring significant modifications to existing equipment, thus reducing the cost of technology iteration. At the same time, its large-size design, low cost, and long-term stability fully meet the requirements of industrial water electrolysis for hydrogen production, which demands large-scale and long-cycle operation of the electrode. This electrode can replace precious metal Pt / C catalysts, ensuring high hydrogen evolution activity while reducing hydrogen production costs, thus promoting the large-scale production of green hydrogen energy. Moreover, the preparation process is environmentally friendly and produces no pollutants, which is highly consistent with the "green and low-carbon" concept of water electrolysis for hydrogen production and can contribute to the development of the clean energy industry. Attached Figure Description

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] Figure 1 This is a SEM image of the highly active, large-size electrolytic hydrogen evolution electrode of Example 3 of the present invention, magnified to 50 μm. Figure 2 This is a 50µm SEM image of the hydrogen evolution electrode for water electrolysis in Comparative Example 1 of this invention. Figure 3 This is a 2µm SEM image of the highly active, large-size electrolytic hydrogen evolution electrode for water electrolysis in Example 1 of this invention. Figure 4 This is a 2µm SEM image of the highly active, large-size electrolytic hydrogen evolution electrode for water electrolysis in Example 2 of this invention. Figure 5 This is a 2µm SEM image of the highly active, large-size electrolytic hydrogen evolution electrode for water electrolysis in Example 3 of this invention. Figure 6 This is a 2µm SEM image of the highly active, large-size electrolytic hydrogen evolution electrode for water electrolysis in Example 4 of this invention. Figure 7 This is a 2µm SEM image of the highly active, large-size electrolytic hydrogen evolution electrode for water electrolysis in Example 5 of this invention. Figure 8 This is a 2µm SEM image of the highly active, large-size electrolytic hydrogen evolution electrode for water electrolysis in Example 6 of this invention. Figure 9 These are the XRD patterns of the electrodes of Embodiment 3 and Comparative Example 1 of the present invention; Figure 10This is an enlarged XRD pattern of the highly active, large-size electrolytic hydrogen evolution electrode of Example 3 of the present invention; Figure 11 These are LSV comparison diagrams of the hydrogen evolution electrodes for water electrolysis in Examples 1-4 and Comparative Examples 1-2 of this invention; Figure 12 This is a comparison chart of the Tafel slopes of the hydrogen evolution electrodes for water electrolysis in Examples 1-4 and Comparative Examples 1-2 of the present invention; Figure 13 These are LSV curves of total water splitting by electrodes in Embodiment 3 and Comparative Example 2 of the present invention; Figure 14 This is a stability test diagram of the highly active, large-size electrolytic hydrogen evolution electrode of Example 3 of the present invention after working for 10 hours. Detailed Implementation

[0029] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0030] The terminology used in the embodiments of this application is for the purpose of describing particular implementations only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the implementations of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0031] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0032] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass described in the embodiments of this application can be a mass unit known in the chemical industry, such as ug, mg, g, or kg.

[0033] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0034] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this application are commercially available or can be prepared using existing methods; for example, the sources of the raw materials or equipment involved in the following examples and comparative examples are as follows: Nickel foam: Purchased from Suzhou Shengernuo Technology Co., Ltd.; Laser processing equipment: Model LPS-355-S; purchased from Changchun New Industries Optoelectronic Technology Co., Ltd. Pt / C: Model SPT20; purchased from Suzhou Shengernuo Technology Co., Ltd.

[0035] Example 1

[0036] This embodiment discloses a highly active, large-size water electrolysis hydrogen evolution electrode, which is prepared according to the following steps: Step 1: Cut 1.6mm thick nickel foam into rectangular pieces of 1cm×2cm to serve as nickel foam substrate; Place the nickel foam substrate in acetone, anhydrous ethanol and deionized water in sequence, and ultrasonically clean each at 40kHz for 15min to thoroughly remove grease, oxides and other organic impurities from the surface; After cleaning, place it in an oven at 60℃ for 12h to dry for later use. Step 2: A nanosecond pulsed laser with a wavelength of 532 μm in the ultraviolet band was used. The dried nickel foam substrate was flatly fixed on the three-dimensional moving platform of the laser processing equipment. The pulse width was set to 7.987 ns, the average output energy per pulse was 150 mJ, the pulse repetition frequency was 5 Hz, the scanning speed was 40 μm / s, and the distance between the laser spot and the sample surface was 15 cm. Then, the laser processing equipment was started, and the laser beam was used to perform a single scan ablation on the surface of the nickel foam substrate. The entire process was carried out in the ambient atmosphere. Step 3: Place the laser-scanned product in anhydrous ethanol and ultrasonically clean it for 2 minutes to remove a small amount of loose deposited particles adhering to the surface; after removal, dry it at room temperature to obtain a highly active, large-size electrolytic water hydrogen evolution electrode, labeled as Ni / NiO-5.

[0037] Example 2

[0038] Compared with Example 1, the only difference is that in step 2, the pulse repetition frequency is set to 10Hz, while the other steps and conditions remain the same, and a highly active large-size electrolytic water hydrogen evolution electrode is finally obtained, labeled as Ni / NiO-10.

[0039] Example 3

[0040] Compared with Example 1, the only difference is that in step 2, the pulse repetition frequency is set to 15Hz, while the other steps and conditions remain the same, and a highly active large-size electrolytic water hydrogen evolution electrode is finally obtained, labeled as Ni / NiO-15.

[0041] Example 4

[0042] Compared with Example 1, the only difference is that in step 2, the pulse repetition frequency is set to 20Hz, while the other steps and conditions remain the same, and a highly active large-size electrolytic water hydrogen evolution electrode is finally obtained, labeled as Ni / NiO-20.

[0043] Example 5

[0044] Compared with Example 3, the only difference is that in step 2, the pulse width is set to 5ns, the average output energy of a single pulse is 50mJ, the scanning speed is 10um / s, and the distance between the light spot and the sample surface is 20cm; other steps and conditions are kept the same, and finally a highly active large-size electrolytic water hydrogen evolution electrode is obtained, labeled as Ni / NiO-15(2).

[0045] Example 6

[0046] Compared with Example 3, the only difference is that in step 2, the pulse width is set to 10 ns, the average output energy of a single pulse is 300 mJ, the scanning speed is 50 μm / s, and the distance between the light spot and the sample surface is 18 cm; other steps and conditions are kept the same, and finally a highly active large-size electrolytic water hydrogen evolution electrode is obtained, labeled as Ni / NiO-15(3).

[0047] Comparative Example 1

[0048] Compared with Example 3, the only difference is that steps 2 and 3 are canceled, and only step 1 is retained; the final electrode is labeled Ni Foam.

[0049] Comparative Example 2

[0050] A commercially available, expensive Pt / C catalyst electrode with excellent electrochemical performance was directly selected as the control electrode, denoted as Pt / C.

[0051] The Ni / NiO-15 of Example 3 and the Ni Foam of Comparative Example 1 were scanned by scanning electron microscopy (SEM) to obtain the following results: Figure 1-2 The SEM image shown, in which, Figure 1 This is a SEM image of Ni / NiO-15 magnified to 50µm. Figure 2 For Ni Foam SEM images magnified to 50µm, Figure 1-2 Observation and analysis show that the surface of Ni / NiO-15 is rich in micro-nano structures, exhibiting a porous and rough morphology (micro-nano structure layer) composed of nanoparticles and molten deposits, while the surface of Ni Foam is smooth and a micro-nano structure layer is formed. This indicates that, compared with Comparative Example 1, steps 2-3 in Example 3 play a role in constructing a micro-nano structure layer on the electrode surface, and the specific surface area is significantly increased.

[0052] The Ni / NiO-5, Ni / NiO-10, Ni / NiO-15, and Ni / NiO-20 samples from Examples 1-4 were further magnified and scanned using a scanning electron microscope (SEM) to obtain the following results: Figure 3-6 The SEM image shown, in which, Figure 3 This is a SEM image of Ni / NiO-5 magnified to 2µm. Figure 4 This is a SEM image of Ni / NiO-10 magnified to 2µm. Figure 5 This is a SEM image of Ni / NiO-15 magnified to 2µm. Figure 6 A SEM image of Ni / NiO-20 magnified to 2µm. Figure 3-6 Observation and analysis show that as the pulse frequency increases from 5Hz to 20Hz, the density of the electrode surface structure and the size distribution of nanoparticles in the micro-nano structure layer change significantly. This indicates that the pulse repetition frequency of the pulsed laser is an effective parameter for controlling the microstructure.

[0053] The Ni / NiO-15(2) and Ni / NiO-15(3) samples from Examples 5-6 were further magnified and scanned using a scanning electron microscope (SEM) to obtain the following results: Figure 7-8 The SEM image shown, in which, Figure 7 The image is a 2µm SEM image of Ni / NiO-15(2). Figure 8 A SEM image of Ni / NiO-15(3) magnified to 2µm, combined with Figure 5 right Figure 7-8 Observation and analysis show that as the pulse width increases from 5 ns to 10 ns, the average output energy per pulse increases from 50 mJ to 300 mJ, and the scanning speed increases from 10 μm / s to 20 μm / s, the density of the electrode surface structure and the size distribution of nanoparticles in the micro-nano structure layer change significantly. This indicates that the pulse width, average output energy per pulse, and scanning speed of pulsed lasers can also be used as effective parameters for controlling the microstructure.

[0054] X-ray diffraction (XRD) was used to analyze the Ni / NiO-15 of Example 3 and the Ni Foam of Comparative Example 1, and the results were as follows: Figure 7-8 The XRD pattern shown is as follows, where, Figure 7 This is the XRD pattern of Ni / NiO-15. Figure 8 This is the XRD pattern of Ni Foam. Figure 7-8Analysis confirmed that the surface phase of Ni / NiO-15 is mainly NiO, while the surface phase of Ni Foam is mainly Ni. This indicates that, compared to Comparative Example 1, steps 2-3 (pulsed laser ablation) in Example 3 effectively constructed a micro-nano structure layer on the electrode surface and successfully generated nickel oxide in situ.

[0055] Electrochemical performance tests were conducted on Ni / NiO-5, Ni / NiO-10, Ni / NiO-15, Ni / NiO-20 from Examples 1-4, Ni Foam from Comparative Example 1, and Pt / C from Comparative Example 2. The test method involved using a standard three-electrode system in 0.1 MKOH electrolyte to test the hydrogen evolution reaction performance of each electrode. Using Ni / NiO-5, Ni / NiO-10, Ni / NiO-15, Ni / NiO-20, Ni Foam, and Pt / C as working electrodes, Hg / HgO as the reference electrode, and a graphite rod as the counter electrode, linear sweep voltammetry (LSV) and Tafel slope measurements were performed to obtain the following results: Figure 9 The LSV comparison chart and Tafel slope comparison chart are shown; for Figure 9 Analysis revealed that the electrode performance of Examples 1-4 was significantly superior to that of Comparative Example 1. Among them, the Ni / NiO-15 electrode exhibited the best performance at a current density of 10 mA / cm². -2 At that time, its overpotential is as low as about 152mV; reaching 100mAcm -2 At that time, the overpotential was approximately 290 mV, second only to Pt / C in Comparative Example 2; for Figure 10 Analysis revealed that the slopes of Examples 1-4 were significantly higher than those of Comparative Example 1, with the Tafel slope of the Ni / NiO-15 electrode being approximately 144 mVdec. -1 This indicates that it has faster HER reaction kinetics, second only to Pt / C in Comparative Example 2; combined with Figure 9-10 It can be determined that steps 2-3 (pulsed laser ablation) of the present invention improve the electrochemical performance of the electrode, enabling it to achieve an electrochemical performance close to that of Pt / C under the premise of controllable cost.

[0056] Chronopotential testing was performed on Ni / NiO-15 from Example 3. The testing method was as follows: a constant current density of 100 mA / cm² was used. -2 The operating potential was continuously tested for 10 hours, and the decay of the operating potential was observed. The test results are as follows: Figure 11-12 As shown, where, Figure 11 The LSV curves for the total water splitting of Ni / NiO-15 in Example 3 and Pt / C in Comparative Example 2 are shown. Figure 12After 10 hours of continuous testing of Ni / NiO-15 in Example 3 at 100 mA / cm² -2 Stability test graph under current density; Figure 11-12 Analysis confirmed that the operating potential of Ni / NiO-15 did not decrease significantly after 10 hours of operation, demonstrating excellent long-term operational stability.

[0057] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A highly active, large-size electrolytic water electrolysis hydrogen evolution electrode, characterized in that, It includes a nickel foam substrate and a nickel oxide micro / nano structure layer generated in situ on the skeleton surface of the nickel foam substrate by pulsed laser ablation.

2. The highly active, large-size hydrogen evolution electrode for water electrolysis according to claim 1, characterized in that, The main component of the nickel oxide micro / nano structure layer is NiO.

3. The highly active, large-size water electrolysis hydrogen evolution electrode according to claim 1, characterized in that, The nickel oxide micro / nano structure layer has a porous and rough microstructure.

4. A method for preparing a highly active, large-size water electrolysis hydrogen evolution electrode, used to prepare the highly active, large-size water electrolysis hydrogen evolution electrode as described in any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Pre-treat the nickel foam substrate sequentially; Step 2: Perform a single line scan on the cleaned nickel foam substrate using a pulsed laser at a scanning speed of 10-50 μm / s.

5. The method for preparing a highly active, large-size water electrolysis hydrogen evolution electrode according to claim 4, characterized in that, In step 1, the pretreatment method is as follows: cut the nickel foam substrate to the required size, and then perform ultrasonic cleaning in acetone, ethanol and deionized water in sequence. After cleaning, dry it for later use.

6. The method for preparing a highly active, large-size water electrolysis hydrogen evolution electrode according to claim 4, characterized in that, In step 2, the pulsed laser is an ultraviolet laser with a wavelength of 532 μm.

7. The method for preparing a highly active, large-size water electrolysis hydrogen evolution electrode according to claim 4, characterized in that, In step 2, the pulse repetition frequency of the pulsed laser is 5-20Hz, the pulse width is 5-10ns, the average output energy of a single pulse is 50-300mJ, and the distance from the laser spot to the surface of the nickel foam substrate is 10-20cm.

8. The method for preparing a highly active, large-size water electrolysis hydrogen evolution electrode according to claim 4, characterized in that, It also includes the following step 3: Step 3: Perform ultrasonic cleaning and drying on the laser-scanned product.

9. The method for preparing a highly active, large-size water electrolysis hydrogen evolution electrode according to claim 8, characterized in that, The ultrasonic cleaning method is as follows: The product after laser scanning is placed in anhydrous ethanol for 2 minutes for cleaning.

10. An application of the highly active, large-size hydrogen evolution electrode for water electrolysis as described in any one of claims 1-3, characterized in that, Used for the alkaline electrolysis of water to produce hydrogen.

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