Hydrogen evolution electrode and preparation method thereof

Abstract

The invention relates to the technical field of electrolytic hydrogen production, in particular to a hydrogen evolution electrode and a preparation method thereof. The hydrogen evolution electrode comprises a foamed nickel substrate and a Pt-plated cobalt hydroxide nanosheet array which grows on the surface of the foamed nickel substrate in situ, the cobalt hydroxide nanosheet array is uniformly dispersed on the surface of the foamed nickel, and Pt is an amorphous Pt nanocluster which is uniformly dispersed on the surface of the cobalt hydroxide nanosheet. The hydrogen evolution electrode has the advantages of being simple in preparation process, low in cost, high in Pt utilization rate, good in catalytic performance, high in stability and the like, and has wide application prospects in the technical field of seawater electrolysis hydrogen production.

Description

Technical Field

[0001] This invention relates to the field of electrolytic hydrogen production technology, and in particular to a hydrogen evolution electrode and its preparation method. Background Technology

[0002] Hydrogen energy, as a pollution-free, sustainable, and high-calorific-value renewable energy source, is considered a substitute for fossil fuels and currently has important applications in energy, chemical engineering, and power generation. Water electrolysis for hydrogen production stands out among numerous hydrogen production methods due to its advantages such as low carbon emissions, high hydrogen production efficiency, and high hydrogen purity. Currently, the HER kinetics of seawater electrolysis cathodes are slow. While using the precious metal Pt offers good activity, the cost associated with high loading cannot be ignored. Furthermore, the negative zeta potential of Pt nanoparticles attracts calcium and magnesium ions from seawater, forming hydroxide precipitates that coat the active sites, hindering mass transfer and resulting in poor stability.

[0003] To address these issues, many researchers have attempted to reduce Pt loading by controlling precursor processing conditions through thermochemical methods such as impregnation and calcination. However, at high temperatures, Pt atoms tend to sinter and agglomerate into large particles, resulting in catalysts with high activity but poor stability, and without significant improvement in calcium and magnesium deposition. Some researchers have also prepared non-noble metal catalysts with specific morphologies, mostly mono- or multi-component transition metal nitrides, phosphides, and sulfides such as Co supported on NF surfaces. x P, NiMoN@NF, NiCoP@NF, NiCoS@NF, etc., were used to prepare ordered electrodes by controlling experimental conditions through hydrothermal and chemical vapor deposition methods to achieve rapid mass transfer of gas and ions. Although the use of non-noble metals reduced the cost of the catalyst, the hydrogen evolution activity was far inferior to that of Pt: one reason being the significant difference in intrinsic activity between noble and non-noble metals, which depends on the interaction between the metal and H. ad According to the HBE theory, only noble metals located at the top of the volcano-type curve have excellent intrinsic hydrogen evolution activity. On the other hand, seawater is weakly alkaline and has a low ion concentration, so the slow dissociation of water molecules (Volmer step) limits the HER reaction rate. In addition, the above-mentioned synthesis method has many disadvantages such as long cycle, complicated steps, poor controllability, and high energy consumption, which are not conducive to large-scale industrial production. Summary of the Invention

[0004] To address the aforementioned technical challenges, this invention provides a hydrogen evolution electrode comprising a nickel foam substrate and an array of Pt-plated cobalt hydroxide nanosheets grown in situ on the surface of the nickel foam (NF) substrate; the cobalt hydroxide nanosheet array is uniformly dispersed on the surface of the nickel foam, and the Pt is an amorphous Pt nanocluster uniformly dispersed on the surface of the cobalt hydroxide nanosheets.

[0005] Preferably, the thickness of the nickel foam substrate is 1-2 mm; and / or, the thickness of the cobalt hydroxide nanosheets is 10-30 nm; and / or, the loading of the cobalt hydroxide nanosheets is 1.5-2.5 mg cm⁻¹. -2 ; and / or, the Pt loading is 0.1~0.2 mg cm⁻¹. -2 .

[0006] The hydrogen evolution electrode of this invention utilizes a uniformly dispersed array of Pt-plated cobalt hydroxide nanosheets grown on the surface of NF. This uniformly dispersed structure provides a richer number of HER active sites. Furthermore, the amorphous Pt nanoclusters, compared to stable crystal structures, expose more active sites without activation, effectively improving Pt utilization. The nanosheet array structure facilitates gas and ion mass transfer during the hydrogen evolution process. The electronic interaction between Pt and Co optimizes the adsorption energies for H* and OH*, accelerating water dissociation and thus speeding up hydrogen evolution. Therefore, the hydrogen evolution electrode provided by this invention exhibits excellent hydrogen evolution activity even with low Pt loading.

[0007] Furthermore, in the hydrogen evolution electrode of the present invention, Pt material is deposited on cobalt hydroxide nanosheets. The positively charged Co(OH)2 nanosheets are used to control the Pt with a predominantly negative zeta potential. This can maintain activity while also electrostatically repelling calcium and magnesium ions, thus suppressing their effect of generating hydroxides that poison the electrode during the HER process. The cobalt hydroxide nanosheets in the hydrogen evolution electrode can form an array of pore structures. This structure is beneficial for timely transporting the small amount of precipitate generated in situ to the flow channel and out of the electrolytic cell under the influence of electrolyte or hydrogen, preventing it from clogging the active sites.

[0008] Furthermore, the present invention provides a method for preparing the hydrogen evolution electrode, comprising: (1) The acid-treated nickel foam was placed in a cobalt nitrate solution for pre-activation, and then Co(OH)2@NF was obtained by electrodeposition. (2) The hydrogen evolution electrode (Pt@Co(OH)2@NF) is prepared by electrodeposition in an alkaline solution containing Pt salt.

[0009] The method for preparing the hydrogen evolution electrode provided by this invention involves pre-activation before electrodeposition of Co(OH)₂, which can effectively promote the OH evolution process. - Intercalation and adsorption on the NF substrate surface provide a favorable environment for synthesizing Co(OH)₂ nanosheets with uniform thickness and distribution. By synthesizing Pt via electrodeposition on the Co(OH)₂ surface, the Pt loading can be precisely controlled by adjusting the synthesis conditions. Due to the multiple deposition sites and anchoring effect of Co(OH)₂, Pt atoms can be uniformly deposited and stably exist on the catalyst surface in an amorphous nanocluster state.

[0010] Preferably, the Pt salt is K2PtCl4; and / or, the alkaline solution is an aqueous solution of NaOH; and / or, the acid is hydrochloric acid.

[0011] Preferably, the concentration of the cobalt nitrate solution is 0.05~0.2 M; and / or, the concentration of the acid is 1~5 M; and / or, the concentration of the Pt salt is 25~250 μM; and / or, the concentration of the alkali solution is 0.5~2 M.

[0012] Preferably, in step (1) during pre-activation and electrodeposition, nickel foam is used as the working electrode, graphite sheet is used as the counter electrode, and saturated calomel electrode is used as the reference electrode. In step (2) electrodeposition, Co(OH)2@NF is used as the working electrode, graphite sheet is used as the counter electrode, and saturated calomel electrode is used as the reference electrode.

[0013] Preferably, the pre-activation conditions in step (1) are: 10~40 mA cm⁻¹ -2 The reaction is carried out for 300~900 s; and / or, the electrodeposition conditions for step (1) are: at -10~-40 mA cm⁻¹ -2 Electrodeposition for 300~900 s; and / or, the electrodeposition conditions for step (2) are: 40~60 mV·s in the range of -0.4~0 V vs. RHE. -1 The cyclic voltammetric scan is performed at a speed of 200-600 revolutions.

[0014] Preferably, the nickel foam is subjected to acid treatment after being washed with acetone and water in sequence.

[0015] Preferably, the cleaning is performed using ultrasonic cleaning.

[0016] Preferably, the amount of acetone used is 5-20 mL per square centimeter of NF.

[0017] Preferably, the amount of hydrochloric acid used is 4~10 mL of NF per square centimeter.

[0018] Preferably, the ultrasonic power is 100~300 W and the ultrasonic time is 3~30 min.

[0019] Preferably, the Pt@Co(OH)2@NF obtained in step (2) is washed with deionized water and then dried overnight in a vacuum oven at 60 °C to obtain the hydrogen evolution electrode.

[0020] Furthermore, the present invention provides the application of the hydrogen evolution electrode or the preparation method described herein in the preparation of seawater electrolyzers or seawater electrolytic hydrogen evolution.

[0021] Furthermore, the present invention provides a seawater electrolysis cell containing the hydrogen evolution electrode described above or the hydrogen evolution electrode prepared by the preparation method described above.

[0022] The hydrogen evolution electrode of this invention further accelerates the slow kinetics of HER due to the bifunctional effect of Pt and Co in the seawater electrochemical hydrogen evolution process. Three-electrode tests were performed on this electrode in natural seawater at -10 mA cm⁻¹. -2 The overpotential at half-cell is only 155 mV, and the overpotential at half-cell is -100 mA·cm. -2 It can operate stably for 230 hours with a full battery capacity of 100 mA·cm⁻¹ -2 The voltage was 1.68V, and the potential did not increase significantly after stable operation for more than 200 hours.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a hydrogen evolution electrode that can be used for seawater electrolysis and its preparation method. The electrode has the advantages of simple preparation process, low cost, high Pt utilization rate, good catalytic performance and strong stability, and has broad application prospects in the field of seawater electrolysis hydrogen production technology. Attached Figure Description

[0024] Figure 1 Scanning electron microscope images of Example 1 and Comparative Examples 1, 2, and 3; a. Example 1, b. Comparative Example 1, c. Comparative Example 2, d. Comparative Example 3.

[0025] Figure 2 Example 1 and Comparative Examples 1, 2, and 3 were tested in natural seawater at -30 mA·cm⁻¹. -2 Chronopotential curves of the reaction after 10 hours; a. Comparative Example 1, b. Comparative Example 2, c. Comparative Example 3, d. Example 1.

[0026] Figure 3 Images of the actual device before and after the electrode timing potential test.

[0027] Figure 4 Example 1: In natural seawater -100 mA·cm -2 Chronopotential curves of the reaction after 230 h.

[0028] Figure 5 The polarization curves are for half-cell (a) and full-cell (b) of Example 1 and Comparative Examples 1, 2 and 3.

[0029] Figure 6 The durability test curves are for Example 1 and Comparative Example 1.

[0030] Figure 7 The XRD and electron diffraction patterns are those of Example 1.

[0031] Figure 8 XPS plots of Pt 4f and Co 2p orbitals for Example 1, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. In the embodiments provided in this specification, where specific techniques or conditions are not specified, they are performed according to the techniques or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0033] Example 1 This embodiment provides a hydrogen evolution electrode Pt@Co(OH)2@NF, which is prepared by the following method: 1: Cut a 1*2 cm piece 2 The NF sheet with a thickness of 1.5 mm was sonicated with 20 mL of acetone for 15 min and then rinsed with deionized water.

[0034] 2: Take 2.6 mL of concentrated hydrochloric acid and dilute it in 7.5 mL of deionized water to obtain about 3 M hydrochloric acid. Soak the NF tablets treated with acetone in it, sonicate for 6 min, and then rinse them with deionized water.

[0035] 3: Weigh 2.9103 g of Co(NO3)2·6H2O and dissolve it in 100 mL of deionized water as the electrolyte. Use the above-treated NF as the working electrode, a graphite sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Electrolyte temperature is 20 mA cm⁻¹. -2 Pre-activation for 600 s, followed by -20 mA cm⁻¹ -2 Co(OH)2@NF was synthesized by electrodeposition for 600 s.

[0036] 4: Weigh 4.1509 mg of K₂PtCl₄ and 4 g of NaOH, dissolve them in 100 mL of deionized water, and stir well to prepare the electrolyte. Use Co(OH)₂@NF as the working electrode, a graphite sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Electrolyte is applied at 50 mV·s⁻¹ within the range of -0.4 to 0 V vs. RHE. -1 The Pt@Co(OH)2@NF hydrogen evolution electrode was obtained by cyclic voltammetry scanning for 400 cycles. After being cleaned with deionized water, the Pt@Co(OH)2@NF hydrogen evolution electrode was dried overnight in a vacuum oven at 60 °C for later use.

[0037] Example 2 This embodiment provides a hydrogen evolution electrode Pt@Co(OH)2@NF, which is prepared by the following method: 1: Cut a 1*2 cm piece 2 NF sheets with a thickness of 2 mm were sonicated with 40 mL of acetone for 10 min and then rinsed with deionized water.

[0038] 2: Take 2.6 mL of concentrated hydrochloric acid and dilute it in 12.5 mL of deionized water to obtain about 2 M hydrochloric acid. Soak the NF tablets treated with acetone in it, sonicate for 10 min, and then rinse them with deionized water.

[0039] 3: Weigh 5.8206 g of Co(NO3)2·6H2O and dissolve it in 100 mL of deionized water as the electrolyte. Use the above-treated NF as the working electrode, a graphite sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Electrolyte temperature is 30 mA cm⁻¹. -2 Pre-activation for 300 s, followed by -30 mA cm⁻¹ -2 Co(OH)2@NF was synthesized by electrodeposition for 300 s.

[0040] 4. Weigh 8.3018 mg of K₂PtCl₄ and 8 g of NaOH, dissolve them in 100 mL of deionized water, and stir well to prepare the electrolyte. Use Co(OH)₂@NF as the working electrode, a graphite sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Electrolyte is applied at 50 mV·s⁻¹ within the range of -0.4 to 0 V vs. RHE. -1 The Pt@Co(OH)2@NF hydrogen evolution electrode was obtained by 200 cycles of cyclic voltammetry scanning. After being cleaned with deionized water, the Pt@Co(OH)2@NF hydrogen evolution electrode was dried overnight in a vacuum oven at 60 °C for later use.

[0041] Comparative Example 1 This comparative example provides a hydrogen evolution electrode Pt@NF, which is prepared by the following method: 1: Cut a 1*2 cm piece 2 NF sheets with a thickness of 2 mm were sonicated with 20 mL of acetone for 15 min and then rinsed with deionized water.

[0042] 2: Take 3 mL of concentrated hydrochloric acid and dilute it in 6 mL of deionized water to obtain about 4 M hydrochloric acid. Soak the NF tablets treated with acetone in it, sonicate for 5 min, and then rinse them with deionized water.

[0043] 3: Weigh 4.1509 mg K₂PtCl₄ and 4 g NaOH, dissolve them in 100 mL of deionized water, and stir well to prepare the electrolyte. Use NF as the working electrode, graphite sheet as the counter electrode, and saturated calomel electrode as the reference electrode. Electrolyte is applied at 50 mV·s within the range of -0.4 to 0 V vs. RHE. -1 The Pt@NF was obtained by cyclic voltammetry scanning for 400 cycles, and then washed, dried and stored for later use.

[0044] Comparative Example 2 This comparative example provides a hydrogen evolution electrode Co(OH)2@NF, which is prepared by the following method: 1: Cut a 1*2 cm piece 2 NF sheets with a thickness of 1.5 mm were sonicated with 25 mL of acetone for 10 min and then rinsed with deionized water.

[0045] 2: Take 2.6 mL of concentrated hydrochloric acid and dilute it in 7.5 mL of deionized water to obtain about 3 M hydrochloric acid. Soak the NF tablets treated with acetone in it, sonicate for 15 min, and then rinse them with deionized water.

[0046] 3: Weigh 5.8206 g of Co(NO3)2·6H2O and dissolve it in 100 mL of deionized water as the electrolyte. Use the above-treated NF as the working electrode, a graphite sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Electrolyte temperature is 20 mA cm⁻¹. -2 Pre-activation for 600 s, followed by -20 mA·cm -2 Co(OH)2@NF was synthesized by electrodeposition for 600 s.

[0047] Comparative Example 3 This comparative example provides a hydrogen evolution electrode Co(OH)2@Pt@NF, and the preparation method is as follows: 1: Cut a 1*2 cm piece 2 NF sheets with a thickness of 1.5 mm were sonicated with 20 mL of acetone for 12 min and then rinsed with deionized water.

[0048] 2: Take 3 mL of concentrated hydrochloric acid and dilute it in 6 mL of deionized water to obtain about 4 M hydrochloric acid. Soak the NF tablets treated with acetone in it, sonicate for 15 min, and then rinse them with deionized water.

[0049] 3: Weigh 4.1509 mg K₂PtCl₄ and 4 g NaOH, dissolve them in 100 mL of deionized water, and stir well to prepare the electrolyte. Use NF as the working electrode, graphite sheet as the counter electrode, and saturated calomel electrode as the reference electrode. Electrolyte is applied at 50 mV·s within the range of -0.4 to 0 V vs. RHE. -1The Pt@NF was obtained by cyclic voltammetry scanning for 400 cycles, and then washed, dried and stored for later use.

[0050] 4: Weigh 2.9103 g of Co(NO3)2·6H2O and dissolve it in 100 mL of deionized water as the electrolyte. Use Pt@NF as the working electrode, a graphite sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Electrolyte temperature is 25 mA·cm⁻¹. -2 Pre-activation for 600 s, followed by -25 mA·cm -2 Co(OH)2@Pt@NF was synthesized by electrodeposition for 600 s.

[0051] Test case The hydrogen evolution electrodes prepared in different embodiments and comparative examples were characterized by SEM, and the test results are as follows: Figure 1 As shown, a. Example 1, b. Comparative Example 1, c. Comparative Example 2, d. Comparative Example 3.

[0052] Upon testing, the thickness of the nickel foam in the hydrogen evolution electrode of Example 1 was found to be 1.5 mm; the thickness of the cobalt hydroxide nanosheets was 28.6 nm; and the loading of the cobalt hydroxide nanosheets was 2.2 mg / cm³. -2 The Pt loading was 0.156 mg / cm³. -2 .

[0053] Furthermore, the hydrogen evolution electrodes prepared in the examples and comparative examples were subjected to HER activity and stability tests in natural seawater. The hydrogen evolution electrode was used as the working electrode, the saturated calomel electrode as the reference electrode, the Pt sheet as the counter electrode, and natural seawater as the electrolyte. Linear voltammetric scan curves and chronopotential curves were measured, and the results are shown in Table 1. ΔE represents the HER activity and stability of the electrodes at a current density of -30 mA cm⁻¹. -2 The increment of overpotential after 10 hours of timing potential testing (ΔE = E) 10 h -E 0 h ), Δm represents the current density at -30 mA cm⁻¹ -2 The increase in electrode mass due to calcium and magnesium hydroxide deposition after 10 hours of chronopotential testing (Δm=m) 10 h -m 0 h ).

[0054] Table 1 Electrochemical test results

[0055] As can be seen from Table 1, Example 1 at -10 mA cm -2The overpotential was 155 mV, and the HER performance was the best, even higher than that of the pure Pt-containing electrode Pt@NF in Comparative Example 1. This indicates that the bifunctional synergistic catalytic effect of Pt and Co in the hydrogen evolution electrode provided by this invention, as well as the exposure of multiple active sites due to the high specific surface area of ​​Co(OH)2 nanosheets, can maintain excellent catalytic performance. Comparative Example 2 showed poor catalytic performance due to the lack of Pt introduction. In Comparative Example 3, Pt was deposited first, followed by Co(OH)2. The change in the deposition order resulted in most or even completely coating of the Pt particles deposited on the NF surface by Co(OH)2 nanosheets, which could not form amorphous Pt clusters. The Pt particles were not very uniform and had low utilization, so the HER activity was also relatively poor.

[0056] Subsequently at -30 mA•cm -2 Its stability was observed after running for 10 hours, and the chronopotential curve is shown below. Figure 2 As shown, the actual images of the electrode before and after the chronopotential test are as follows. Figure 3 As shown, Comparative Example 2 exhibits the best stability, followed by Example 1 and Comparative Example 3. Comparative Example 1 shows the worst stability, which is consistent with the trend of electrode mass change before and after the stability test. This confirms that the performance degradation mainly comes from the deposition of calcium and magnesium hydroxide. In the electrode containing the Co(OH)2 nanosheet array structure, the overpotential increase is not significant, and the electrode mass change is not significantly different from that of Comparative Example 1, indicating that Co(OH)2 nanosheets can inhibit deposition. The embodiments of the present invention have excellent reactivity while ensuring a certain degree of stability.

[0057] Subsequently, the half-cell stability of Example 1 was tested in natural seawater. The half-cell was prepared as follows: seawater was added to both sides of an H-type electrolytic cell, separated by a Nafion 115 membrane. Using the electrode prepared in Example 1 as the working electrode, a Pt sheet as the counter electrode, and a saturated calomel electrode as the reference electrode, the stability was tested at -100 mA•cm. -2 A timing potential test was then performed. The timing potential curve is shown below. Figure 4 As shown, -100 mA•cm -2 After 230 hours of stable operation, the overpotential showed no significant increase. Full-cell activity tests were conducted on Examples 1, 1, and 2 in natural seawater. The preparation method of the full cells is as follows: using CrO... x @CoO x The anode is Ti, the cathode is the electrode prepared above, and the sodium ion exchange membrane is the diaphragm. The cells are fixed and current-collecting structures formed by two metal plates. The battery temperature is controlled at 80℃ using a heating rod, and the seawater flow rate on both sides is 20 mL / min. -1 A voltage of 1~2.5V was applied by an external power supply, and the polarization curve of the battery was recorded. Then, a 100 mA cm⁻¹ voltage was applied.-2 The current was measured, and the voltage across the battery terminals was recorded over time. The test results are as follows: Figure 5 As shown, Example 1 exhibits the best performance. Example 1 and Comparative Example 1 underwent full-cell durability testing in natural seawater, as... Figure 6 As shown, Example 1 ran stably for more than 200 hours, while Comparative Example 1 only ran for 40 hours.

[0058] In addition, by Figure 7 The XRD and electron diffraction patterns show that the Pt synthesized by electrodeposition in Example 1 did not exhibit a Pt peak in the XRD pattern, and no bright spots representing crystals appeared in the electron diffraction pattern, confirming the amorphous state of Pt on the surface of Co(OH)2 nanosheets. Figure 8 XPS plots of Pt 4f and Co 2p orbitals in Example 1, Comparative Examples 1 and 2 show that Pt and Co in Example 1 have strong electronic interactions, specifically the shift of Pt's electron cloud toward Co. This change in electronic state means that the adsorption energy of the atom on the intermediate is modulated, which is the main reason why the two promote the HER rate through bifunctional catalysis.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydrogen evolution electrode, characterized in that, It includes a nickel foam substrate and an array of Pt-plated cobalt hydroxide nanosheets grown in situ on the surface of the nickel foam substrate; the cobalt hydroxide nanosheet array is uniformly dispersed on the surface of the nickel foam, and the Pt is an amorphous Pt nanocluster uniformly dispersed on the surface of the cobalt hydroxide nanosheets.

2. The hydrogen evolution electrode according to claim 1, characterized in that, The thickness of the nickel foam substrate is 1-2 mm; and / or the thickness of the cobalt hydroxide nanosheets is 10-30 nm; and / or the loading of the cobalt hydroxide nanosheets is 1.5-2.5 mg cm⁻¹. -2 ; and / or, the Pt loading is 0.1~0.2 mg cm⁻¹. -2 .

3. The method for preparing the hydrogen evolution electrode according to claim 1 or 2, characterized in that, include: (1) The acid-treated nickel foam was placed in a cobalt nitrate solution for pre-activation, and then Co(OH)2@NF was obtained by electrodeposition. (2) The hydrogen evolution electrode is prepared by electrodeposition of Co(OH)2@NF in an alkaline solution containing Pt salt.

4. The preparation method according to claim 3, characterized in that, The Pt salt is K2PtCl4; and / or, the alkaline solution is an aqueous solution of NaOH; and / or, the acid is hydrochloric acid.

5. The preparation method according to claim 3, characterized in that, The concentration of the cobalt nitrate solution is 0.05~0.2M; and / or, the concentration of the acid is 1~5M; and / or, the concentration of the Pt salt is 25~250 μM; and / or, the concentration of the alkali solution is 0.5~2M.

6. The preparation method according to claim 3, characterized in that, In step (1), during pre-activation and electrodeposition, nickel foam is used as the working electrode, graphite sheet is used as the counter electrode, and saturated calomel electrode is used as the reference electrode.

7. The preparation method according to claim 3, characterized in that, In step (2) electrodeposition, Co(OH)2@NF is used as the working electrode, a graphite sheet is used as the counter electrode, and a saturated calomel electrode is used as the reference electrode.

8. The preparation method according to claim 3, characterized in that, The pre-activation conditions for step (1) are: 10~40 mAcm -2 The reaction is carried out for 300~900 s; and / or, the electrodeposition conditions for step (1) are: at -10~-40 mA cm⁻¹ -2 Electrodeposition for 300~900 s; and / or, the electrodeposition conditions for step (2) are: 40~60 mV·s in the range of -0.4~0 V vs. RHE. -1 The cyclic voltammetric scan is performed at a speed of 200-600 revolutions.

9. The application of the hydrogen evolution electrode according to claim 1 or 2 or the preparation method according to any one of claims 3 to 8 in the preparation of seawater electrolyzers or seawater electrolysis hydrogen evolution.

10. A seawater electrolysis cell, characterized in that, It contains the hydrogen evolution electrode as described in claim 1 or 2, or the hydrogen evolution electrode prepared by the preparation method described in any one of claims 3 to 8.

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