A ruthenium monatomic / nickel single substance / β-phase nickel hydroxide catalyst, a preparation method and application thereof

Abstract

This invention discloses a method for preparing a ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst. First, an m-Ni(OH)₂ nanosheet array is loaded onto a support via a hydrothermal reaction. Then, plasma activation treatment is used to partially reduce the m-Ni(OH)₂ to metallic nickel, while simultaneously transforming the m-Ni(OH)₂ into β-phase Ni(OH)₂ (β-Ni(OH)₂). Finally, Ru single atoms (Ru SA) are electrodeposited on its surface to obtain the catalyst. This invention also discloses the application of the above electrocatalyst in the hydrogen evolution reaction of water electrolysis. The HER catalyst of this invention is low in cost and exhibits excellent catalytic efficiency and stability. It can efficiently and stably catalyze the hydrogen evolution reaction of water electrolysis under alkaline conditions, showing promising application prospects.

Description

Technical Field

[0001] This invention relates to the field of electrocatalyst materials technology, and in particular to a ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst, its preparation method, and its application. Background Technology

[0002] Hydrogen, due to its environmental friendliness and high energy density, is considered one of the main energy carriers with the potential to replace fossil fuels. Hydrogen production through water electrolysis using electricity generated from sustainable energy sources such as solar and wind power is a sustainable method. Water electrolysis is a method of storing renewable energy in the form of chemical bonds. Simultaneously, electrocatalytic hydrogen production helps alleviate global problems such as environmental pollution, global warming, and the energy crisis caused by the large-scale combustion of fossil fuels. Extensive research has been conducted on water electrolysis in both acidic and alkaline electrolytes. Very few OER electrocatalysts can operate stably in acidic electrolytes. Therefore, water electrolysis in alkaline electrolytes has attracted widespread attention, and developing a low-cost electrocatalyst that can efficiently and stably catalyze the hydrogen evolution reaction in water electrolysis under alkaline conditions is of significant practical importance. Summary of the Invention

[0003] Based on the technical problems existing in the background art, the present invention proposes a ruthenium single atom / nickel element / β phase nickel hydroxide catalyst, its preparation method and application.

[0004] The present invention proposes a method for preparing a ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst, comprising the following steps:

[0005] S1. Ni(NO3)2·6H2O, NH4F and urea are dissolved in deionized water to obtain a precursor solution; the support is placed in the precursor solution and subjected to a hydrothermal reaction to obtain a support loaded with m-Ni(OH)2 nanosheet arrays.

[0006] S2. The loaded m-Ni(OH)2 nanosheet array is placed in the cavity of the radio frequency plasma device and plasma activation is performed in a mixed atmosphere of hydrogen and argon to obtain a carrier for the loaded β-Ni(OH)2 / Ni heterostructure nanosheet array.

[0007] S3. A three-electrode system is formed by using a support for a β-Ni(OH)2 / Ni heterostructure nanosheet array as the working electrode, Hg / HgO as the reference electrode, and a carbon rod as the counter electrode. A KOH solution containing RuCl3 is used as the electrolyte, and electrodeposition is performed by cyclic voltammetry to obtain a ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst. The concentration of RuCl3 in the KOH solution containing RuCl3 is 100-300 μmol / L, and the concentration of KOH is 1 mol / L.

[0008] Preferably, in S1, the mass ratio of Ni(NO3)2·6H2O, NH4F and urea is (0.8-1):(0.2-0.4):(0.8-1).

[0009] Preferably, the carrier is nickel foam.

[0010] Before use, the carrier needs to be thoroughly cleaned. The specific steps can be: ultrasonic cleaning with ethanol, 3M hydrochloric acid and deionized water in sequence, followed by vacuum drying.

[0011] Preferably, in S1, the temperature of the hydrothermal reaction is 110-130℃ and the time is 10-15h.

[0012] Preferably, in S2, the mixed atmosphere of hydrogen and argon is composed of hydrogen and argon in a volume ratio of (7-9):(1-3).

[0013] Preferably, in S2, the plasma activation treatment has a pressure of 50-80 Pa, a power of 300-500 W, and a treatment time of 10-30 min.

[0014] Preferably, in S3, the alkaline solution containing RuCl3 is a RuCl3 KOH solution with a concentration of 100-300 μmol / L, wherein the concentration of KOH is 0.5-2 mol / L.

[0015] Preferably, the scanning voltage range for electrodeposition by cyclic voltammetry is 0 to -0.5V vs. RHE, the number of scan cycles is 8-15, and the scan rate is 3-8 mV·s. -1 .

[0016] The present invention also discloses a ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst, which is prepared by the aforementioned preparation method.

[0017] The present invention also discloses the application of the ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst in the hydrogen evolution reaction of water electrolysis.

[0018] The beneficial effects of this invention are as follows:

[0019] This invention first loads an m-Ni(OH)₂ nanosheet array onto a support via a hydrothermal reaction, then uses plasma activation to partially reduce the m-Ni(OH)₂ to metallic nickel, simultaneously transforming it into β-phase Ni(OH)₂ (β-Ni(OH)₂), resulting in a β-Ni(OH)₂ / Ni heterostructure nanosheet array. This increases the electrochemical active area and the number of active sites, while the presence of metallic nickel enhances the conductivity of Ni(OH)₂. Next, Ru single atoms (Ru SA) are electrodeposited on its surface to prepare a ruthenium single-atom / nickel / β-phase nickel hydroxide catalyst (β-Ni(OH)₂ / Ni-Ru SA). The use of ruthenium single atoms reduces the amount of commercial catalyst required, thereby lowering the catalyst cost. The HER catalyst of this invention is low in cost and exhibits excellent catalytic efficiency and stability. It can efficiently and stably catalyze the electrolysis of water for hydrogen evolution under alkaline conditions, showing promising application prospects. Attached Figure Description

[0020] Figure 1 The structural characterization diagrams are shown for the m-Ni(OH)₂ catalyst prepared in Comparative Example 4 and the β-Ni(OH)₂ / Ni catalyst prepared in Comparative Example 1. Figure 1 (a) is the XRD pattern of the m-Ni(OH)2 catalyst. Figure 1 (b) are scanning electron microscope images of the m-Ni(OH)2 catalyst at low and high magnification. Figure 1 (c) is a transmission electron microscope image of the m-Ni(OH)2 catalyst at low magnification. Figure 1 (d) is the XRD pattern of the β-Ni(OH)2 / Ni catalyst. Figure 1 (e) shows the scanning electron microscope (SEM) images of the β-Ni(OH)2 / Ni catalyst at low and high magnification. Figure 1 (f) is a transmission electron microscope image of the β-Ni(OH)2 / Ni catalyst at low magnification.

[0021] Figure 2 The image shows the structural characterization of the β-Ni(OH)₂ / Ni-Ru SA catalyst prepared in Example 1. Figure 2 (a) is the XRD pattern of the β-Ni(OH)2 / Ni-Ru SA catalyst. Figure 2 (b) are scanning electron microscope images of the β-Ni(OH)2 / Ni-Ru SA catalyst at low and high magnification. Figure 2 (c) is a transmission electron microscope image of the β-Ni(OH)2 / Ni-Ru SA catalyst at low magnification. Figure 2 (d) is the high-resolution transmission spectrum of the β-Ni(OH)2 / Ni-Ru SA catalyst. Figure 2 (e) is the HAADF-STEM image of the β-Ni(OH)2 / Ni-Ru SA catalyst. Figure 2(fi) is the EDS diagram of the β-Ni(OH)2 / Ni-Ru SA catalyst.

[0022] Figure 3 The images show the XPS and synchrotron radiation patterns of Ru 3p in the β-Ni(OH)₂ / Ni-Ru SA catalyst prepared in Example 1. Figure 3 (a) is the XPS plot of Ru 3p. Figure 3 (b) Ni K-edge XANES spectra of Ni(OH)2 / Ni-Ru SA, Ni foil, and Ni(OH)2. Figure 3 (c) shows the FT-EXAFS spectra of Ni in Ni foil, Ni(OH)2 / Ni-Ru SA, and Ni(OH)2. Figure 3 (d) shows the Ru K-edge XANES spectral lines. Figure 3 (e) represents the relationship between the Ru K-edge energy and the valence state. Figure 3 (f) shows the FT-EXAFS spectra of Ru in Rufoil, Ni(OH)2 / Ni-Ru SA and RuO2.

[0023] Figure 4 The figures show the performance test results of the β-Ni(OH)2 / Ni-Ru SA catalyst prepared in Example 1 of this invention and the β-Ni(OH)2 / Ni, β-Ni(OH)2, β-Ni(OH)2-Ru and m-Ni(OH)2 catalysts prepared in Comparative Examples 1-4. Figure 4 (a) is the LSV diagram. Figure 4 (b) is a Tafel diagram. Figure 4 (c) is the EIS diagram. Figure 4 (d) is the ECSA diagram. Figure 4 (e) The prepared β-Ni(OH)2 / Ni-RuSA catalyst was subjected to a test at 20 mA / cm². -2 Stability plot at current density.

[0024] Figure 5 The LSV comparison diagram shows the catalysts prepared in 1M KOH containing different concentrations of RuCl3 electrolyte in Examples 1, 5, and 6 of this invention.

[0025] Figure 6 This is a structural characterization diagram of the catalyst prepared in Comparative Example 5 of this invention using 1M KOH containing 50μM RuCl3 electrolyte. Figure 6 (a) is the XRD pattern of the Ni(OH)2 / Ni-Ru SA-50μM catalyst. Figure 6 (b) is a scanning electron microscope image of the Ni(OH)2 / Ni-Ru SA-50μM catalyst. Figure 6(c) is a transmission electron microscope image of the Ni(OH)2 / Ni-Ru SA-50μM catalyst at low magnification. Figure 6 (d) is a transmission electron microscope image of the Ni(OH)2 / Ni-Ru SA-50μM catalyst at high magnification.

[0026] Figure 7 This is a structural characterization diagram of the catalyst prepared in Comparative Example 6 of this invention using 1M KOH containing 800μM RuCl3 electrolyte. Figure 7 (a) is the XRD pattern of the Ni(OH)2 / Ni-Ru SA-800μM catalyst. Figure 7 (b) is a scanning electron microscope image of the Ni(OH)2 / Ni-Ru SA-800μM catalyst. Figure 7 (c) is a transmission electron microscope image of the Ni(OH)2 / Ni-Ru SA-800μM catalyst under low magnification. Figure 7 (d) is a transmission electron microscope image of the Ni(OH)2 / Ni-Ru SA-800μM catalyst at high magnification. Detailed Implementation

[0027] The technical solution of the present invention will now be described in detail through specific embodiments.

[0028] Example 1

[0029] Preparation of ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst (β-Ni(OH)2 / Ni-Ru SA):

[0030] S1. Add 0.931g Ni(NO3)2·6H2O, 0.237g NH4F and 0.971g urea to a reactor containing 80mL deionized water and stir for 30min to obtain a precursor solution. Clean the nickel foam (3cm*3cm) sequentially with ethanol, 3M hydrochloric acid and deionized water by ultrasonication, vacuum dry it and place it in the precursor solution. Then place the reactor in a constant temperature drying oven and perform hydrothermal reaction at 120℃ for 12h. Take out the nickel foam, wash it with deionized water and then dry it in a vacuum drying oven to obtain nickel foam supported on m-Ni(OH)2 nanosheet array.

[0031] S2. Place the nickel foam loaded with m-Ni(OH)2 nanosheet array in the cavity of the radio frequency plasma device, and introduce a mixture of hydrogen and argon (H2:Ar = 9:1) into the cavity. Perform plasma activation treatment for 20 min under the conditions of 60 Pa pressure and 400 W plasma power in the cavity to obtain nickel foam loaded with β-Ni(OH)2 / Ni heterostructure nanosheet array.

[0032] S3. A three-electrode system was formed using nickel foam supported on a β-Ni(OH)2 / Ni heterostructure nanosheet array as the working electrode, Hg / HgO as the reference electrode, and a carbon rod as the counter electrode. A 200 μmol / L RuCl3 KOH solution (KOH concentration 1 mol / L) was used as the electrolyte. Electrodeposition was performed using cyclic voltammetry, with a scanning voltage range of 0 to -0.5 V vs. RHE, 10 scan cycles, and a scan rate of 5 mV·s. -1 A ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst was obtained, denoted as Ni(OH)2 / Ni-Ru SA-200μM.

[0033] Comparative Example 1

[0034] Preparation of elemental nickel / β-phase nickel hydroxide catalyst (β-Ni(OH)2 / Ni):

[0035] S1. Add 0.931g Ni(NO3)2·6H2O, 0.237g NH4F and 0.971g urea to a reactor containing 80mL deionized water and stir for 30min to obtain a precursor solution. Clean the nickel foam (3cm*3cm) sequentially with ethanol, 3M hydrochloric acid and deionized water by ultrasonication, vacuum dry it and place it in the precursor solution. Then place the reactor in a constant temperature drying oven and perform hydrothermal reaction at 120℃ for 12h. Take out the nickel foam, wash it with deionized water and then dry it in a vacuum drying oven to obtain nickel foam supported on m-Ni(OH)2 nanosheet array.

[0036] S2. Place the loaded m-Ni(OH)2 nanosheet array in the cavity of the radio frequency plasma device, and introduce a mixture of hydrogen and argon (H2:Ar = 9:1) into the cavity. Perform plasma activation treatment for 20 minutes under the conditions of 60 Pa pressure and 400 W plasma power in the cavity.

[0037] Comparative Example 2

[0038] Preparation of β-phase nickel hydroxide catalyst (β-Ni(OH)2):

[0039] S1. Add 0.931g Ni(NO3)2·6H2O, 0.237g NH4F and 0.971g urea to a reactor containing 80mL deionized water and stir for 30min to obtain a precursor solution. Clean the nickel foam (3cm*3cm) sequentially with ethanol, 3M hydrochloric acid and deionized water by ultrasonication, vacuum dry it and place it in the precursor solution. Then place the reactor in a constant temperature drying oven and perform hydrothermal reaction at 120℃ for 12h. Take out the nickel foam, wash it with deionized water and then dry it in a vacuum drying oven to obtain nickel foam supported on m-Ni(OH)2 nanosheet array.

[0040] S2. Place the nickel foam supported on m-Ni(OH)2 nanosheet array in a reaction vessel containing 0.1M NaOH aqueous solution and hydrothermally react at 180℃ for 2 hours. Then remove the nickel foam, wash it with deionized water, and dry it in a vacuum drying oven to obtain the final product.

[0041] Comparative Example 3

[0042] Preparation of ruthenium single-atom / β-phase nickel hydroxide catalyst (β-Ni(OH)2-Ru SA):

[0043] S1. Add 0.931g Ni(NO3)2·6H2O, 0.237g NH4F and 0.971g urea to a reactor containing 80mL deionized water and stir for 30min to obtain a precursor solution. Clean the nickel foam (3cm*3cm) sequentially with ethanol, 3M hydrochloric acid and deionized water by ultrasonication, vacuum dry it and place it in the precursor solution. Then place the reactor in a constant temperature drying oven and perform hydrothermal reaction at 120℃ for 12h. Take out the nickel foam, wash it with deionized water and then dry it in a vacuum drying oven to obtain nickel foam supported on m-Ni(OH)2 nanosheet array.

[0044] S2. Place the nickel foam supported on m-Ni(OH)2 nanosheet array in a reaction vessel containing 0.1M NaOH aqueous solution and hydrothermally react at 180℃ for 2h. Then remove the nickel foam, wash it with deionized water, and dry it in a vacuum drying oven to obtain nickel foam supported on β-Ni(OH)2 heterostructure nanosheet array.

[0045] S3. A three-electrode system was formed using nickel foam supported on a β-Ni(OH)₂ heterostructure nanosheet array as the working electrode, Hg / HgO as the reference electrode, and a carbon rod as the counter electrode. A 200 μmol / L RuCl₃ KOH solution (KOH concentration 1 mol / L) was used as the electrolyte. Electrodeposition was performed using cyclic voltammetry, with a scanning voltage range of 0 to -0.5 V vs. RHE, 10 scan cycles, and a scan rate of 5 mV·s. -1 That is, you get it.

[0046] Comparative Example 4

[0047] Preparation of mixed-phase nickel hydroxide catalyst (m-Ni(OH)2):

[0048] S1. Add 0.931g Ni(NO3)2·6H2O, 0.237g NH4F and 0.971g urea to a reactor containing 80mL deionized water and stir for 30min to obtain a precursor solution. Soak nickel foam (3cm*3cm) in ethanol, 3M hydrochloric acid and deionized water in sequence by ultrasonic cleaning, vacuum dry and place it in the precursor solution. Then place the reactor in a constant temperature drying oven and treat it at 120℃ for 12h for hydrothermal reaction. Take out the nickel foam, wash it with deionized water and then dry it in a vacuum drying oven to obtain the final product.

[0049] Comparative Example 5

[0050] The only difference between Comparative Example 5 and Example 1 is the concentration of the electrolyte used in S3. Specifically, a 50 μmol / L RuCl3 KOH solution (KOH concentration of 1 mol / L) was used as the electrolyte. The resulting catalyst is denoted as Ni(OH)2 / Ni-Ru SA-50μM.

[0051] Comparative Example 6

[0052] The only difference between Comparative Example 6 and Example 1 is the concentration of the electrolyte used in S3. Specifically, a RuCl3 KOH solution with a concentration of 800 μmol / L (KOH concentration of 1 mol / L) was used as the electrolyte. The resulting catalyst is denoted as Ni(OH)2 / Ni-Ru SA-800μM.

[0053] Test case

[0054] The catalysts prepared in Example 1 and Comparative Examples 1-6 were characterized and their performance was tested.

[0055] Figure 1 The structural characterization diagrams are shown for the m-Ni(OH)₂ catalyst prepared in Comparative Example 4 and the β-Ni(OH)₂ / Ni catalyst prepared in Comparative Example 1. Figure 1 (a) is the XRD pattern of the m-Ni(OH)2 catalyst. Figure 1 (b) are scanning electron microscope images of the m-Ni(OH)2 catalyst at low and high magnification. Figure 1 (c) is a transmission electron microscope image of the m-Ni(OH)2 catalyst at low magnification. Figure 1 (d) is the XRD pattern of the β-Ni(OH)2 / Ni catalyst. Figure 1(e) shows the scanning electron microscope (SEM) images of the β-Ni(OH)2 / Ni catalyst at low and high magnification. Figure 1 (f) is a transmission electron microscope (TEM) image of the β-Ni(OH)₂ / Ni catalyst at low magnification. To eliminate interference from nickel foam, the sample used for XRD testing was β-Ni(OH)₂ / Ni powder ultrasonically extracted from a nickel foam substrate. Figure 1 As shown, m-Ni(OH)2 is activated by reducing H2 / Ar plasma. Figure 1 (a) and Figure 1 The XRD pattern in (d) shows that Ni(OH)₂ was a mixed phase before plasma activation, and transformed into a β-phase Ni(OH)₂ after activation, while a new species, elemental Ni, appeared. Figure b shows that m-Ni(OH)₂ exhibits a cross-linked nanosheet array structure, with an average nanosheet length of approximately 2 μm. Figure 1 (b) clearly shows that the surface of the nanosheets is smooth and the thickness is about 20 nm. Figure 1 (c) Confirms the smooth and ultrathin properties of m-Ni(OH)2 nanosheets. Figure 1 (e) It can be seen that β-Ni(OH)2 / Ni still maintains the structure of nanosheets, but the nanosheets become bent after plasma activation. Figure 1 (f) Clear nanosheets can be seen in β-Ni(OH)2 / Ni, with nanoparticles and some pores appearing on the nanosheets. This is because the plasma contains a large number of high-energy particles, which bombard the nanosheet array, causing the ultrathin nanosheets to deform or even break through.

[0056] Figure 2 The image shows the structural characterization of the β-Ni(OH)₂ / Ni-Ru SA catalyst prepared in Example 1. Figure 2 (a) is the XRD pattern of the β-Ni(OH)2 / Ni-Ru SA catalyst. Figure 2 (b) are scanning electron microscope images of the β-Ni(OH)2 / Ni-Ru SA catalyst at low and high magnification. Figure 2 (c) is a transmission electron microscope image of the β-Ni(OH)2 / Ni-Ru SA catalyst at low magnification. Figure 2 (d) is the high-resolution transmission spectrum of the β-Ni(OH)2 / Ni-Ru SA catalyst. Figure 2 (e) is the HAADF-STEM image of the β-Ni(OH)2 / Ni-Ru SA catalyst. Figure 2 (f) is the EDS diagram of the β-Ni(OH)2 / Ni-Ru SA catalyst. Figure 2 As shown, Figure 2(a) It can be observed that the XRD diffraction peaks of Ni(OH)2 / Ni after Ru electrodeposition all correspond to Ni and Ni(OH)2, with no diffraction peaks appearing for other substances, especially metallic Ru. From Figure 2 (b) The SEM image shows that electrodeposition did not change the morphology of the β-Ni(OH)2 / Ni nanosheets. Figure 2 (c) The TEM image shows that the structure of the nanosheets embedded with the nanoparticles is still maintained. Figure 2 (d) The high-resolution TEM image shows the presence of a Ni(OH)₂ heterostructure with Ni. And... Figure 2 The clear bright spots in the HAADF-STEM image (e) indicate the presence of Ru SA. Figure 2 The EDS elemental mapping image of (fi) further reveals the presence of Ru, with a quality percentage of only 1%.

[0057] Figure 3 The images show the XPS and synchrotron radiation patterns of Ru 3p in the β-Ni(OH)₂ / Ni-Ru SA catalyst prepared in Example 1. Figure 3 (a) is the XPS plot of Ru 3p. Figure 3 (b) Ni K-edge XANES spectra of Ni(OH)2 / Ni-Ru SA, Ni foil, and Ni(OH)2. Figure 3 (c) shows the FT-EXAFS spectra of Ni in Ni foil, Ni(OH)2 / Ni-Ru SA, and Ni(OH)2. Figure 3 (d) shows the Ru K-edge XANES spectral lines. Figure 3 (e) represents the relationship between the Ru K-edge energy and the valence state. Figure 3 (f) shows the FT-EXAFS spectra of Ru in Rufoil, Ni(OH)2 / Ni-Ru SA, and RuO2. Figure 3 (a) In the XPS spectrum of Ru 3p, the peaks at 463.5 eV (Ru 3p 3 / 2) and 485.7 eV (Ru 3p 3 / 2) belong to Ru δ+ The form corresponds to the Ru atom with a partially positive charge (Ru). δ+ , 0 < δ < 3). The structure of Ni(OH)2 / Ni-Ru SA is further revealed by X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). The k-edge peak of Ni in Ni(OH)2 / Ni-Ru SA is located between Ni foil and Ni(OH)2, indicating that the average valence state of Ni is between Ni0 and Ni0. 2+ Between, such as Figure 3As shown in (b). Similarly, the k-edge absorption peak of Ru is located between Ru foil and RuO2, and its average valence is approximately 2.3, as... Figure 3 (d) and Figure 3 As shown in (e), the coordination structure information of Ni and Ru atoms can be obtained from EXAFS. Figure 3 (c) Showing Ni(OH)2 / Ni-Ru SA at approximately and The peak appearing at [location] is similar to that of Ni(OH)2, approximately [location]. The peaks that appear are consistent with those of Ni foil. For Ru, it is approximately at... The faint peaks that appeared were attributed to Ru-O, while The peaks at these positions primarily indicate Ru-Ni and Ru-Ru coordination, such as... Figure 3 As shown in (f), the presence of Ru-Ru bonds indicates the possible presence of Ru clusters in Ni(OH)2 / Ni-Ru SA. Calculations show that Ru-Ru bonds account for approximately 10%, Ru-Ni bonds for approximately 10%, and Ru-O bonds for as high as 80%. Therefore, the Ru element in Ni(OH)2 / Ni-Ru SA mainly exists in monatomic form.

[0058] The β-Ni(OH)₂ / Ni-Ru SA prepared in the examples, and the β-Ni(OH)₂ / Ni, β-Ni(OH)₂, β-Ni(OH)₂-Ru, and m-Ni(OH)₂ catalysts prepared in Comparative Examples 1-4 were used as working electrodes in a three-electrode system (counter electrode: carbon rod electrode, reference electrode: Hg / HgO electrode). The voltage range was tested using linear sweep voltammetry (LSV) curves in the range of 0 to -0.5 V. Specifically, as shown... Figure 4 As shown. Figure 4 (a) It can be seen that β-Ni(OH)2 / Ni-Ru SA reaches 10 and 100 mAcm -2 The current required is only 16 and 67 mV overpotential, respectively, which far exceeds the performance of other catalysts and Pt / C electrodes. Figure 4 (b) It can be seen that the Tafel slope of β-Ni(OH)2 / Ni-RuSA in alkaline electrolyte is 21 mV dec. -1 Similarly, it is less than Pt / C (32mV dec) -1 The smaller Tafel slope of β-Ni(OH)₂ / Ni-Ru SA indicates that the introduced Ru SA significantly accelerates HER kinetics. Meanwhile, from... Figure 4(c) The EIS results show that the extremely small radius of β-Ni(OH)₂ / Ni-RuSA indicates its low charge transfer resistance, confirming that the addition of RuSA is beneficial for accelerating reaction kinetics. To further elucidate the reason for the high activity of β-Ni(OH)₂ / Ni-RuSA, Figure 4 (d) The ECSA of each electrocatalyst can be seen. The ECSA value of β-Ni(OH)2 / Ni-Ru SA is 209 mF cm⁻¹. -2 The value is greater than that of other catalysts, indicating that Ni(OH)2 / Ni-Ru SA exposes more electrochemical active sites. Figure 4 (e) It can be seen that the curve of β-Ni(OH)2 / Ni-Ru SA continuously producing hydrogen for 250 h at 20 mA cm-2 did not change significantly, which shows that β-Ni(OH)2 / Ni-Ru SA has excellent stability in 1M KOH.

[0059] The Ni(OH)₂ / Ni-Ru SA-50 μM catalyst prepared in Comparative Example 5, the Ni(OH)₂ / Ni-Ru SA-200 μM catalyst prepared in Example 1, and the Ni(OH)₂ / Ni-Ru SA-800 μM catalyst prepared in Comparative Example 6 were used as working electrodes in a three-electrode system (counter electrode: carbon rod electrode, reference electrode: Hg / HgO electrode). The voltage range of 0 to -0.5 V was tested using linear sweep voltammetry (LSV), as detailed below. Figure 5 As shown in the figure, when the concentration of RuCl3 is 200 μM, the electrodeposited electrocatalyst exhibits better HER performance. When the concentration of RuCl3 is too low or too high, it leads to insufficient Ru SA and the formation of Ru clusters (such as...). Figure 6 and Figure 7 As shown in the figure, HER performance degrades.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst, characterized in that, Includes the following steps: S1. Ni(NO3)2·6H2O, NH4F and urea are dissolved in deionized water to obtain a precursor solution; the support is placed in the precursor solution and subjected to a hydrothermal reaction to obtain a support for m-Ni(OH)2 nanosheet arrays. S2. The support loaded with m-Ni(OH)2 nanosheet arrays is placed in the cavity of a radio frequency plasma device and plasma activation is performed in a mixed atmosphere of hydrogen and argon to obtain the support loaded with β-Ni(OH)2 / Ni heterostructure nanosheet arrays. S3. A three-electrode system is formed by using a support for a β-Ni(OH)2 / Ni heterostructure nanosheet array as the working electrode, Hg / HgO as the reference electrode, and a carbon rod as the counter electrode. A KOH solution containing RuCl3 is used as the electrolyte, and electrodeposition is performed by cyclic voltammetry to obtain a ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst. In the KOH solution containing RuCl3, the concentration of RuCl3 is 100-300 μmol / L, and the concentration of KOH is 1 mol / L.

2. The preparation method of the ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst according to claim 1, characterized in that, In S1, the mass ratio of Ni(NO3)2·6H2O, NH4F and urea is (0.8-1):(0.2-0.4):(0.8-1).

3. The preparation method of the ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst according to claim 1, characterized in that, The carrier is nickel foam.

4. The preparation method of the ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst according to claim 1, characterized in that, In S1, the hydrothermal reaction is carried out at a temperature of 110-130℃ for a time of 10-15 hours.

5. The preparation method of the ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst according to claim 1, characterized in that, In S2, the mixed atmosphere of hydrogen and argon is composed of hydrogen and argon in a volume ratio of (7-9):(1-3).

6. The method for preparing the ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst according to claim 1, characterized in that, In S2, the plasma activation treatment has a pressure of 50-80 Pa, a power of 300-500 W, and a treatment time of 10-30 min.

7. The method for preparing the ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst according to claim 1, characterized in that, The scanning voltage range for electrodeposition using cyclic voltammetry is 0 to -0.5 V vs. RHE, the number of scan cycles is 8-15, and the scan rate is 3-8 mV·s. -1 .

8. A ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. The application of the ruthenium single-atom / nickel element / β-phase nickel hydroxide catalyst according to claim 8 in the hydrogen evolution reaction of water electrolysis.

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