A method for the preparation of transition metal-based hydroxides

Abstract

The application belongs to the field of chemistry and particularly relates to a preparation method of a transition metal-based hydroxide. The transition metal-based hydroxide is obtained by using a transition metal acetylacetone salt as a precursor and performing alkalization treatment. The preparation method has high safety and feasibility, simple preparation steps, good prospects for large-scale application, and can be used to prepare both a powder catalyst and a self-supporting electrode. The prepared transition metal-based hydroxide catalyst and electrode have excellent electrochemical performance.

Description

Technical Field

[0001] This invention belongs to the field of chemistry, specifically relating to a method for preparing transition metal-based hydroxides. Background Technology

[0002] With continuous societal development, human demand for energy and chemicals is constantly increasing, and the production of chemicals heavily relies on the utilization and conversion of fossil fuels. As industrialization and urbanization advance, domestic energy demand has surged. However, my country's primary energy source remains fossil fuels, which bring a series of ecological and environmental problems. Therefore, reducing the use of non-renewable fossil fuels and developing and utilizing renewable resources is a current and future trend. Biomass energy is the only renewable and abundant renewable resource that can meet human demand for chemicals.

[0003] To replace fossil fuels, researchers have sought and developed numerous new clean energy sources. Common clean energy sources include geothermal, hydropower, wind power, tidal power, solar power, biomass energy, ocean energy, and hydrogen energy. Among these, hydrogen energy, as a highly promising green and clean energy source, has received widespread attention and is one of the most attractive new energy sources. A crucial method for obtaining hydrogen energy is water electrolysis, which involves the oxygen evolution reaction (OER) at the anode and the hydrogen evolution reaction (HER) at the cathode. Replacing the slow-kinetic OER with an organic matter conversion reaction can reduce the voltage of the electrolyzer, lower energy consumption, and convert bioderivable organic matter from the anode reaction into high-value-added chemicals, improving the economic efficiency of the electrolyzer. Nitrogen is one of the basic elements constituting living matter and plays a vital role in life. Although nitrogen makes up about 78% of the air volume, it can only be used for biosynthesis after being converted into ammonia (NH3). NH3 is also an irreplaceable industrial chemical raw material, playing an important role in fertilizer production, pharmaceuticals, and the textile industry. Meanwhile, due to its high hydrogen content, ease of liquefaction, storage, and transportation, NH3 has become an ideal carbon-free energy carrier. Therefore, global demand for ammonia continues to increase. Currently, electrochemical nitrogen reduction reaction (NRR) is a promising method for artificial nitrogen fixation. With increasing industrialization and energy consumption, atmospheric carbon dioxide concentrations are gradually increasing, causing serious damage to the ecological environment. Therefore, there is an urgent need to generate new clean energy sources to reduce carbon dioxide emissions. Among numerous carbon dioxide conversion technologies, electrocatalytic carbon dioxide reduction reaction (CO2RR) is a promising technology that can fully utilize electrical energy to convert carbon dioxide into desired new energy products under the action of a catalyst, reducing the carbon dioxide content in the air, and has broad application prospects. Therefore, reactions such as HER, OER, NRR, CO2RR, and organic matter conversion have received widespread attention.

[0004] Transition metal-based hydroxides are widely used electrocatalysts in various reactions such as HER, OER, NRR, CO2RR, and organic conversion, mainly due to their abundant reserves, low cost, and flexible tunable electronic structure. Preparation methods are crucial for the study of catalyst mechanisms and applications. However, each electrocatalyst preparation method has its drawbacks. The hydrothermal method is a common approach for preparing transition metal-based hydroxides, but it is not ideal in terms of energy consumption, environmental friendliness, and safety. Other methods, such as electrodeposition and etching, can be carried out under environmental conditions, but they have limitations in terms of composition / structure tuning, multifunctionality, and scalability. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for preparing transition metal-based hydroxides, which is simple, universal and scalable, and is of great significance for the research and application of transition metal-based hydroxides.

[0006] This invention specifically provides a method for preparing transition metal-based hydroxides, which uses transition metal acetylacetonate as a precursor and obtains the transition metal-based hydroxides through alkalization treatment.

[0007] As a preferred embodiment, the transition metal-based hydroxide is a powdered transition metal-based hydroxide catalyst or a transition metal-based hydroxide electrode.

[0008] When the transition metal-based hydroxide is a powdered transition metal-based hydroxide catalyst, it is prepared according to the following steps:

[0009] (1) Transition metal acetylacetone salt and carbon black were ball-milled to obtain a mixed powder;

[0010] (2) The mixed powder obtained in step (1) is ultrasonically vibrated in an alkaline solution to obtain a powdered transition metal-based hydroxide catalyst.

[0011] As a preferred embodiment, in step (1), the mass ratio of transition metal acetylacetone salt to carbon black is 1:25 to 2:1; the transition metal acetylacetone salt is one or more of nickel acetylacetone, cobalt acetylacetone, iron acetylacetone, and copper acetylacetone.

[0012] As a preferred embodiment, in step (2), the alkaline solution is a KOH solution or a NaOH solution with a concentration of 0.1 mol / L to 5 mol / L; and the ultrasonic oscillation time is 20 min to 60 min.

[0013] When the transition metal-based hydroxide is a transition metal-based hydroxide electrode, it is prepared according to the following steps:

[0014] (1) Dissolve the transition metal acetylacetone salt in dimethyl sulfoxide to obtain a solution;

[0015] (2) The solution from step (1) is drop-coated onto the electrode substrate and then dried;

[0016] (3) Immerse the dried electrode from step (2) in an alkaline solution to obtain a transition metal-based hydroxide electrode.

[0017] As a preferred embodiment, in step (1), the transition metal acetylacetone salt is one or more of nickel acetylacetone, cobalt acetylacetone, iron acetylacetone, and copper acetylacetone; the mass concentration of the transition metal acetylacetone salt in the solution is 1 g / L to 45 g / L.

[0018] As a preferred option, the electrode substrate in step (2) is carbon paper, carbon felt, nickel foam, or stainless steel mesh.

[0019] As a preferred option, in step (3), the alkaline solution is a KOH solution or a NaOH solution with a concentration of 0.1 mol / L to 5 mol / L; the soaking time is 20 min to 60 min.

[0020] The design concept of this invention is: utilizing OH - The acetylacetone ligand that replaces the transition metal acetylacetone salt generates a transition metal hydroxide.

[0021] The present invention has the following advantages:

[0022] 1) All material processing in this invention is carried out at room temperature and pressure, which ensures high safety and feasibility, while hydrothermal methods usually require high temperature and high pressure environments above 100°C.

[0023] 2) The steps of this invention are simple and have good prospects for large-scale application, while the amount synthesized in one step by the usual etching method and electrodeposition method is limited;

[0024] 3) This invention can prepare hydroxides into powdered catalysts or directly into electrodes, and the composition can be adjusted over a wide range, while conventional methods such as hydrothermal methods or electrodeposition can often only prepare hydroxides with specific compositions and forms. Attached Figure Description

[0025] Figure 1a This is a flowchart of the preparation process for Example 1;

[0026] Figure 1b The XRD pattern of Ni(OH)2 / CB obtained in Example 1;

[0027] Figure 1c The image shows a TEM image of Ni(OH)2 / CB obtained in Example 1.

[0028] Figure 1d The image shows the HR-TEM image of Ni(OH)2 / CB obtained in Example 1.

[0029] Figure 1e The image shows the HR-TEM image of Ni(OH)2 / CB obtained in Example 1.

[0030] Figure 1f The image shows the HR-TEM image of Ni(OH)2 / CB obtained in Example 1.

[0031] Figure 1g The HAADF and elemental distribution diagram of Ni(OH)2 / CB obtained in Example 1 are shown below.

[0032] Figure 2a SEM image of a blank carbon felt electrode;

[0033] Figure 2b -d is the SEM image of Ni(OH)2 / CF obtained in Example 12;

[0034] Figure 2e The elemental distribution diagram of Ni(OH)2 / CF obtained in Example 12 is shown below.

[0035] Figure 3a -b is the SEM image of Ni(OH)2 / NF obtained in Example 13;

[0036] Figure 4a Ni obtained in Example 7 0.75 Co 0.25 XRD pattern of (OH)2 / CB;

[0037] Figure 4b -c represents the Ni obtained in Example 7. 0.75 Co 0.25 XPS plot of (OH)2 / CB;

[0038] Figure 4d -e represents the Ni obtained in Example 7. 0.75 Co 0.25 TEM image of (OH)2 / CB;

[0039] Figure 4f Ni obtained in Example 7 0.75 Co 0.25 HR-TEM image of (OH)2 / CB;

[0040] Figure 4g Ni obtained in Example 7 0.75 Co 0.25 HAADF and elemental distribution diagram of (OH)2 / CB;

[0041] Figure 5aThe distribution diagram of the Ni(OH)2 / CB oxidation electrolysis products at a potential of 1.5V obtained in Example 1 is shown.

[0042] Figure 5b The image shows the Ni(OH)2 / CF obtained in Example 12 applied to an anion exchange membrane electrolyzer for continuous 80-hour electrolysis of 5-hydroxymethylfurfural. Detailed Implementation

[0043] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0044] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0045] Example 1:

[0046] First, XC-72R carbon black (CB) was pretreated. 2.5 g of CB was placed in a 500 mL three-necked round-bottom flask, and 0.5 M H₂SO₄ (300 mL) was added. The mixture was heated to 80 °C and refluxed for 3 h with magnetic stirring. After cooling to room temperature, it was filtered, washed with ultrapure water until neutral, and dried in an 80 °C forced-air drying oven for 12 h. 0.9017 g of Ni(acac)₂ and 1 g of the pretreated CB were placed in an agate ball mill jar, and 10 8 mm diameter grinding balls were added. The mixture was ball-milled for 4 h to obtain Ni(acac)₂ / CB. Take 200 mg of Ni(acac)₂ / CB, add 40 mL of 1 M KOH, sonicate for 1 h, centrifuge at 8000 rpm for 5 min, separate the supernatant, add the remaining precipitate to 40 mL of ultrapure water and shake to mix, repeat centrifugation 3 times, and then dry the final precipitate in an 80℃ forced-air drying oven for 12 h. The obtained material is named Ni(OH)₂ / CB, and the Ni element content is calculated to be 20.6 wt% according to the feed ratio. Figures 1a-1g This indicates that nickel hydroxide carbon black powder was successfully prepared. Figure 5a The results indicate that the prepared nickel hydroxide carbon black powder has good catalytic performance in oxidizing 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid, and that the prepared transition metal hydroxide powder has good catalytic activity.

[0047] Example 2:

[0048] First, XC-72R carbon black (CB) was pretreated. 2.5 g of CB was placed in a 500 mL three-necked round-bottom flask, and 0.5 M H₂SO₄ (300 mL) was added. The mixture was heated to 80 °C and refluxed for 3 h with magnetic stirring. After cooling to room temperature, it was filtered, washed with ultrapure water until neutral, and dried in an 80 °C forced-air drying oven for 12 h. 1.3529 g of Ni(acac)₂ and 1 g of the pretreated CB were placed in an agate ball mill jar, and 10 8 mm diameter grinding balls were added. The mixture was ball-milled for 4 h to obtain Ni(acac)₂ / CB. Take 200 mg Ni(acac)2 / CB, add 1 M KOH (40 mL), sonicate for 1 h, centrifuge at 8000 rpm for 5 min, separate the supernatant, add the remaining precipitate to 40 mL of ultrapure water and shake to mix, repeat centrifugation 3 times, and then dry the final precipitate in an 80℃ forced-air drying oven for 12 h. The obtained material is named Ni(OH)2 / CB, and the Ni element content is calculated to be 30.9 wt% according to the feed ratio.

[0049] Example 3:

[0050] First, XC-72R carbon black (CB) was pretreated. 2.5 g of CB was placed in a 500 mL three-necked round-bottom flask, and 0.5 M H₂SO₄ (300 mL) was added. The mixture was heated to 80 °C and refluxed for 3 h with magnetic stirring. After cooling to room temperature, it was filtered, washed with ultrapure water until neutral, and dried in an 80 °C forced-air drying oven for 12 h. 0.4509 g of Ni(acac)₂ and 1 g of the pretreated CB were placed in an agate ball mill jar, and 10 8 mm diameter grinding balls were added. The mixture was ball-milled for 4 h to obtain Ni(acac)₂ / CB. Take 200 mg Ni(acac)2 / CB, add 1 M KOH (40 mL), sonicate for 1 h, centrifuge at 8000 rpm for 5 min, separate the supernatant, add the remaining precipitate to 40 mL of ultrapure water and shake to mix, repeat centrifugation 3 times, and then dry the final precipitate in an 80℃ forced-air drying oven for 12 h. The obtained material is named Ni(OH)2 / CB, and the Ni element content is calculated to be 10.3 wt% according to the feed ratio.

[0051] Example 4:

[0052] First, XC-72R carbon black (CB) was pretreated. 2.5 g of CB was placed in a 500 mL three-necked round-bottom flask, and 0.5 M H₂SO₄ (300 mL) was added. The mixture was heated to 80 °C and refluxed for 3 h with magnetic stirring. After cooling to room temperature, it was filtered, washed with ultrapure water until neutral, and dried in an 80 °C forced-air drying oven for 12 h. 0.0451 g of Ni(acac)₂ and 1 g of the pretreated CB were placed in an agate ball mill jar, and 10 8 mm diameter grinding balls were added. The mixture was ball-milled for 4 h to obtain Ni(acac)₂ / CB. Take 200 mg Ni(acac)2 / CB, add 1 M KOH (40 mL), sonicate for 1 h, centrifuge at 8000 rpm for 5 min, separate the supernatant, add the remaining precipitate to 40 mL of ultrapure water and shake to mix, repeat centrifugation 3 times, and then dry the final precipitate in an 80℃ forced-air drying oven for 12 h. The obtained material is named Ni(OH)2 / CB, and the Ni element content is calculated to be 1 wt% according to the feed ratio.

[0053] Example 5:

[0054] First, XC-72R carbon black (CB) was pretreated. 2.5 g of CB was placed in a 500 mL three-necked round-bottom flask, and 0.5 M H₂SO₄ (300 mL) was added. The mixture was heated to 80 °C and refluxed for 3 h with magnetic stirring. After cooling to room temperature, it was filtered, washed with ultrapure water until neutral, and dried in an 80 °C forced-air drying oven for 12 h. 0.2254 g of Ni(acac)₂ and 1 g of the pretreated CB were placed in an agate ball mill jar, and 10 8 mm diameter grinding balls were added. The mixture was ball-milled for 4 h to obtain Ni(acac)₂ / CB. Take 200 mg Ni(acac)2 / CB, add 1 M KOH (40 mL), sonicate for 1 h, centrifuge at 8000 rpm for 5 min, separate the supernatant, add the remaining precipitate to 40 mL of ultrapure water and shake to mix, repeat centrifugation 3 times, and then dry the final precipitate in an 80℃ forced-air drying oven for 12 h. The obtained material is named Ni(OH)2 / CB, and the Ni element content is calculated to be 5 wt% according to the feed ratio.

[0055] Example 6:

[0056] First, XC-72R carbon black (CB) was pretreated. 2.5 g of CB was placed in a 500 mL three-necked round-bottom flask, and 0.5 M H₂SO₄ (300 mL) was added. The mixture was heated to 80 °C and refluxed for 3 h with magnetic stirring. After cooling to room temperature, it was filtered, washed with ultrapure water until neutral, and dried in an 80 °C forced-air drying oven for 12 h. 0.2254 g of Ni(acac)₂ and 1 g of the pretreated CB were placed in an agate ball mill jar, and 10 8 mm diameter grinding balls were added. The mixture was ball-milled for 4 h to obtain Ni(acac)₂ / CB. Take 200 mg Ni(acac)2 / CB, add 1 M NaOH (40 mL), sonicate for 1 h, centrifuge at 8000 rpm for 5 min, separate the supernatant, add the remaining precipitate to 40 mL of ultrapure water and shake to mix, repeat centrifugation 3 times, and then dry the final precipitate in an 80℃ forced-air drying oven for 12 h. The obtained material is named Ni(OH)2 / CB, and the Ni element content is calculated to be 5 wt% according to the feed ratio.

[0057] Example 7:

[0058] 0.6762 g Ni(acac)₂, 0.2254 g Co(acac)₂, and 1 g CB were placed in an agate ball mill jar, and 10 grinding balls with a diameter of 8 mm were added. The mixture was milled for 4 hours, and the resulting material was named 3Ni(acac)₂-Co(acac)₂ / CB. 200 mg of 3Ni(acac)₂-Co(acac)₂ / CB was added to 40 mL of 1 M KOH, sonicated for 1 hour, and centrifuged at 8000 rpm for 5 minutes. The supernatant was separated, and the remaining precipitate was mixed with 40 mL of ultrapure water. The mixture was centrifuged three times, and the final precipitate was dried in an 80℃ oven for 12 hours. The catalyst after alkali treatment was named Ni based on the Ni and Co feed ratio. 0.75 Co 0.25 (OH)2 / CB. Figure 4a -g indicates successful preparation of nickel-cobalt hydroxide carbon black powder, the metal composition of the transition metal hydroxide can be adjusted, and it can be made into a multi-component formulation.

[0059] Example 8:

[0060] 0.7213g Ni(acac)2, 0.1803g Co(acac)2, and 1g CB were placed in an agate ball mill jar, and 10 grinding balls with a diameter of 8mm were added. The mixture was milled for 4 hours, and the resulting material was named 4Ni(acac)2-Co(acac)2 / CB. 200mg of 4Ni(acac)2-Co(acac)2 / CB was added to 40mL of 1M KOH, sonicated for 1 hour, and centrifuged at 8000rpm for 5 minutes. The supernatant was separated, and the remaining precipitate was mixed with 40mL of ultrapure water. The mixture was centrifuged three times, and the final precipitate was dried in an 80℃ oven for 12 hours. The catalyst after alkali treatment was named Ni according to the Ni and Co feed ratio. 0.8 Co 0.2 (OH)2 / CB.

[0061] Example 9:

[0062] 0.4508g Ni(acac)2, 0.4508g Co(acac)2, and 1g of treated CB were placed in an agate ball mill jar, and 10 grinding balls with a diameter of 8mm were added. The mixture was milled for 4 hours, and the resulting material was named Ni(acac)2-Co(acac)2 / CB. 200mg of Ni(acac)2-Co(acac)2 / CB was added to 40mL of 1M KOH, sonicated for 1 hour, and centrifuged at 8000rpm for 5 minutes. The supernatant was separated, and the remaining precipitate was mixed with 40mL of ultrapure water. The mixture was centrifuged three times, and the final precipitate was dried in an 80℃ oven for 12 hours. The catalyst after alkali treatment was named Ni according to the Ni and Co feed ratio. 0.5 Co 0.5 (OH)2 / CB.

[0063] Example 10:

[0064] 0.6011g Ni(acac)2, 0.3005g Co(acac)2, and 1g of treated CB were placed in an agate ball mill jar, and 10 grinding balls with a diameter of 8mm were added. The mixture was milled for 4 hours, and the resulting material was named 2Ni(acac)2-Co(acac)2 / CB. 200mg of 2Ni(acac)2-Co(acac)2 / CB was added to 40mL of 1M KOH, sonicated for 1 hour, and centrifuged at 8000rpm for 5 minutes. The supernatant was separated, and the remaining precipitate was added to 40mL of ultrapure water and mixed by shaking. The centrifugation was repeated 3 times, and the final precipitate was dried in an 80℃ oven for 12 hours. The catalyst after alkali treatment was named Ni according to the Ni and Co feed ratio. 0.67 Co 0.33 (OH)2 / CB.

[0065] Example 11:

[0066] Take 0.1803g Ni(acac)2, 0.1803g Co(acac)2, 0.1803g Cu(acac)2, 0.1803g Fe(acac)2 and 1g of treated CB in an agate ball milling jar, add 10 grinding balls with a diameter of 8mm, and mill for 4 hours. The resulting material is named Ni(acac)2-Co(acac)2 / CB-Cu(acac)2 / CB-Fe(acac)2 / CB. Take 200 mg of Ni(acac)2-Co(acac)2 / CB-Cu(acac)2 / CB-Fe(acac)2 / CB, add 40 mL of 1 M KOH, sonicate for 1 h, centrifuge at 8000 rpm for 5 min, separate the supernatant, add 40 mL of ultrapure water to the remaining precipitate and mix by shaking, repeat centrifugation 3 times, and then dry the final precipitate in an 80℃ forced-air drying oven for 12 h. The catalyst after alkali treatment is named NiCoCu / CB-Fe(OH)2 / CB according to the Ni and Co feed ratio. This shows that the metal composition can be adjusted and multi-component formulations can be prepared.

[0067] Example 12:

[0068] 3 mg of Ni(acac)₂ was completely dissolved in 200 μL of dimethyl sulfoxide and 10 μL of Nafion solution (Nafion solution was used as a modified electrode). All the catalyst ink was drop-coated onto a 1 cm × 3 cm carbon felt (CF) or similar material and dried in a 60 °C oven for 12 h. Then, it was allowed to stand in 50 mL of 1 M KOH solution for 30 min, rinsed with ultrapure water, and allowed to dry completely at room temperature. The resulting material was Ni(OH)₂ / CF. Figure 2a -e indicates that the nickel hydroxide carbon felt electrode was successfully prepared; Figure 5b The results indicate that the prepared nickel hydroxide carbon felt electrode has good catalytic performance in oxidizing 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid, demonstrating its good catalytic activity.

[0069] Example 13:

[0070] 3 mg of Ni(acac)₂ was completely dissolved in 200 μL of dimethyl sulfoxide and 10 μL of Nafion solution. All the catalyst ink was drop-coated onto a 1 cm × 3 cm nickel foam (NF) and dried in a 60 °C oven for 12 h. Then, it was allowed to stand in 50 mL of 1 M KOH solution for 30 min, rinsed with ultrapure water, and allowed to dry completely at room temperature. The resulting product was Ni(OH)₂ / NF. Figure 3a-b indicates the successful preparation of nickel hydroxide foam electrodes. Transition metal hydroxides can be prepared as powders or as electrodes.

[0071] Example 14:

[0072] 3 mg of Ni(acac)₂ was completely dissolved in 200 μL of dimethyl sulfoxide and 10 μL of Nafion solution. All the catalyst ink was drop-coated onto a 1 cm × 3 cm nickel foam (NF) and dried in a 60 °C oven for 12 h. Then, it was allowed to stand in 50 mL of 1 M NaOH solution for 30 min, rinsed with ultrapure water, and allowed to dry completely at room temperature. The resulting product was Ni(OH)₂ / NF.

[0073] Example 15:

[0074] First, XC-72R carbon black (CB) was pretreated. 2.5 g of CB was placed in a 500 mL three-necked round-bottom flask, and 0.5 M H₂SO₄ (300 mL) was added. The mixture was heated to 80 °C and refluxed for 3 h with magnetic stirring. After cooling to room temperature, it was filtered, washed with ultrapure water until neutral, and dried in an 80 °C forced-air drying oven for 12 h. 9.017 g of Ni(acac)₂ and 10 g of the pretreated CB were placed in an agate ball mill jar, and 20 8 mm diameter grinding balls were added. The mixture was ball-milled for 4 h to obtain Ni(acac)₂ / CB. Take 2g of Ni(acac)2 / CB, add 1M KOH (40mL), sonicate for 1h, centrifuge at 8000rpm for 5min, separate the supernatant, add the remaining precipitate to 40mL of ultrapure water and shake to mix, repeat centrifugation 3 times, and then dry the final precipitate in an 80℃ forced-air drying oven for 12h. The obtained material is named Ni(OH)2 / CB, and the Ni element content is calculated to be 20.6wt% according to the feed ratio. This indicates that the preparation scale can be scaled up.

Claims

1. A method for preparing a transition metal-based hydroxide, characterized in that, This transition metal-based hydroxide is a powdered transition metal-based hydroxide catalyst, prepared according to the following steps: (1) A mixed powder is obtained by ball milling transition metal acetylacetone salt and carbon black; wherein the mass ratio of transition metal acetylacetone salt to carbon black is 1:25 to 2:1; the transition metal acetylacetone salt is one or more of nickel acetylacetone, cobalt acetylacetone, iron acetylacetone, and copper acetylacetone. (2) The mixed powder obtained in step (1) is ultrasonically vibrated in an alkaline solution to obtain a powdered transition metal-based hydroxide catalyst, wherein the alkaline solution is a KOH solution or a NaOH solution with a concentration of 0.1 mol / L to 5 mol / L; the ultrasonic vibration time is 20 min to 60 min.

2. A method for preparing a transition metal-based hydroxide, characterized in that, This transition metal-based hydroxide electrode is prepared according to the following steps: (1) A solution is obtained by dissolving a transition metal acetylacetonate in dimethyl sulfoxide; wherein the transition metal acetylacetonate is one or more of nickel acetylacetonate, cobalt acetylacetonate, iron acetylacetonate, and copper acetylacetonate; and the mass concentration of the transition metal acetylacetonate in the solution is 1 g / L to 45 g / L. (2) Apply the solution from step (1) onto the electrode substrate and then dry it; (3) Immerse the dried electrode from step (2) in an alkaline solution to obtain a transition metal-based hydroxide electrode. The alkaline solution is a KOH solution or a NaOH solution with a concentration of 0.1 mol / L to 5 mol / L. The immersion time is 20 min to 60 min.

3. The method for preparing a transition metal-based hydroxide according to claim 2, characterized in that: In step (2), the electrode substrate is carbon paper, carbon felt, nickel foam, or stainless steel mesh.

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