A p-ni s(al,ni) ooh / nf core-shell catalyst for electrocatalytic oxygen evolution and a preparation method and application thereof

Abstract

A P-NiS@(Al, Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution and a preparation method and application thereof belong to the technical field of electrocatalysis. The P-NiS@(Al, Ni)OOH / NF core-shell catalyst is a foam nickel self-supporting catalyst, which comprises a foam nickel NF conductive matrix and a P-NiS@(Al, Ni)OOH core-shell structure grown in situ on the foam nickel NF conductive matrix. The P-NiS@(Al, Ni)OOH core-shell structure comprises a P-NiS nanorod core layer structure and a shell layer structure composed of AlOOH and amorphous NiOOH located on the outer layer of the core layer structure. The outer shell layer structure is rich in oxygen holes, aluminum metal holes and high-valence nickel species, and has excellent water electrolysis oxygen evolution performance. The prepared catalyst has abundant active sites, excellent water electrolysis oxygen evolution reaction performance, simple and environmentally friendly preparation process, and wide application prospect.

Description

Technical Field

[0001] This invention discloses a P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrochemical oxygen evolution, its preparation method, and its application, belonging to the field of electrocatalysis technology. Background Technology

[0002] As human dependence on fossil fuels continues to deepen, environmental problems such as the greenhouse effect and air pollution caused by burning fossil fuels are becoming increasingly prominent. Developing and improving the utilization rate of green and sustainable new energy sources has become crucial to solving these environmental problems (Nano Energy, 2021, 80, 105545; Journal of Catalysis, 2026, 454, 116615.). Hydrogen, as a clean fuel with zero carbon emissions and high combustion efficiency, has attracted widespread attention from researchers worldwide. Among various hydrogen production methods, water electrolysis is considered the most ideal method due to its mild reaction conditions and high product purity (Angewandte Chemie International Edition, 2025, 64, e202505924.). The water electrolysis process mainly includes two half-reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The OER has a slow kinetics and is the rate-determining step that limits the efficiency of hydrogen production from water electrolysis. Therefore, developing high-performance OER catalysts is key to achieving large-scale industrial production of hydrogen.

[0003] Currently, the OER catalysts widely used in industry are mainly noble metal catalysts. However, their low reserves and high prices significantly increase the production cost of hydrogen production through water electrolysis, severely limiting the large-scale commercial application of this technology. In contrast, non-noble transition metal oxides, phosphides, sulfides, nitrides, and boride catalysts have advantages such as abundant reserves, simple preparation, and tunable electronic structures, attracting widespread attention. By controlling their surface structure, the number of active sites in the catalyst can be increased, and the adsorption and desorption energies of reaction intermediates can be optimized, demonstrating great potential to replace noble metal catalysts. Therefore, developing low-cost, high-activity non-noble transition metal OER catalysts is an important way to overcome the current technological bottlenecks.

[0004] Among various non-noble transition metal compound catalysts, transition metal sulfides exhibit excellent catalytic activity in alkaline OER reactions. Self-supported nickel sulfide-based catalysts prepared by nickel foam sulfidation have become a research focus (ACS Applied Material Interfaces, 2016, 8, 5509-5516; ACS Applied Nano Material, 2024, 7, 11931-11941). With the deepening research on OER catalysts, in-situ characterization and mechanistic analysis have confirmed the spontaneous reconstruction of metal sulfides in OER reactions, generating hydroxyl oxides, which are considered the truly active species for OER catalysis (Journal of Materials Chemistry A, 2021, 9, 22129-22139). However, this spontaneous reconstruction involves significant uncertainties. Therefore, researchers have proposed a controlled anodic electrochemical oxidation reconstruction strategy (Chemical Reviews, 2021, 121, 13174-13212; Electrochimica Acta, 2024, 477, 143713). Regulation of the reconstruction process holds promise for creating highly efficient OER catalysts. In our previous work, we achieved excellent OER performance by controlling the anodic electrochemical oxidation reconstruction of phosphorus-doped nickel sulfide (P-NiS). Furthermore, we created a series of highly efficient self-supporting nickel-based OER catalysts by adding bimetallic components such as Fe and Mn or Fe and La during the controlled anodic electrochemical oxidation reconstruction process of nickel phosphide (Catalysis Science & Technology, 2023, 13, 6625-6630; Catalysis Science & Technology, 2024, 14, 5324-5330). However, the excessively high overpotential and high cost limit its large-scale production and commercial use.

[0005] Aluminum is the most abundant metallic element in the Earth's crust, and its electronegativity differs significantly from that of nickel. We hypothesize that by introducing inexpensive aluminum into the controlled anodic electrochemical oxidation reconstruction process of P-NiS in our previous work, we can prepare a low-cost and efficient OER catalyst with broad prospects for industrial application. Summary of the Invention

[0006] To address the issues of excessively high overpotential and high cost of existing transition metal catalysts in alkaline OER reactions, this invention discloses a P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrochemical oxygen evolution, its preparation method, and its application. The catalyst is prepared by introducing aluminum salts into the anodic electrochemical oxidation reconstruction of a phosphorus-doped nickel sulfide self-supporting material supported by nickel foam, obtained by sulfidation of nickel foam in the presence of phosphorus. This catalyst consists of a core-shell structure composed of P-NiS nanorod structures and outer AlOOH and amorphous NiOOH layers, grown in situ on a conductive nickel foam NF matrix. The outer layer is rich in oxygen vacancies, aluminum metal vacancies, and high-valence nickel species, exhibiting excellent oxygen evolution performance in water electrolysis. This effectively solves the technical bottlenecks of insufficient active materials and low catalytic efficiency in existing catalysts.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: A P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution is disclosed. The P-NiS@(Al,Ni)OOH / NF core-shell catalyst is a nickel foam self-supporting catalyst, comprising a nickel foam NF conductive matrix and a P-NiS@(Al,Ni)OOH core-shell structure grown in situ on the nickel foam NF conductive matrix. The P-NiS@(Al,Ni)OOH core-shell structure includes a P-NiS nanorod-shaped core layer structure and a shell layer structure composed of AlOOH and amorphous NiOOH located outside the core layer structure. Furthermore, the outer shell layer structure is rich in oxygen holes, aluminum metal holes, and high-valence nickel species, exhibiting excellent oxygen evolution performance in water electrolysis.

[0008] Furthermore, in the electrocatalytic oxygen evolution P-NiS@(Al,Ni)OOH / NF core-shell catalyst, the mass ratio of the P-NiS@(Al,Ni)OOH core-shell structure to the nickel foam NF conductive matrix is ​​1:(0.4~10).

[0009] A method for preparing a P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution includes the following steps: Step 1: Prepare a hydrochloric acid solution, mix the hydrochloric acid solution with the conductive nickel foam matrix and sonicate it, then wash and dry to obtain pretreated nickel foam NF; Step 2: Add the vulcanizing agent and additives to the solvent and stir to prepare a solution. While stirring, add the phosphating agent to obtain liquid a. Step 3: Transfer liquid a into a hydrothermal reactor, and place the pretreated nickel foam NF from step 1 into liquid a obtained in step 2 within the hydrothermal reactor. Seal the hydrothermal reactor and proceed with hydrothermal treatment. After hydrothermal treatment, remove the nickel foam with phosphorus-doped nickel sulfide growth, wash and dry it to obtain the catalyst precursor. Step 4: Add aluminum salt to solvent to obtain liquid b. Then, under stirring, add liquid b to KOH electrolyte to form a mixed electrolyte. Use the catalyst precursor obtained in step 3 as working electrode, and form a three-electrode system with graphite rod electrode and mercury / mercury oxide electrode. After controlled anodic electrochemical oxidation reconstruction, and then washing and drying, the P-NiS@(Al,Ni)OOH / NF core-shell catalyst can be obtained.

[0010] Further, in step 1, the concentration of the hydrochloric acid solution is 0.5–3 mol / L, the size of the nickel foam conductive matrix is ​​1 cm × 1 cm, the thickness is 0.5–3 mm, the mass ratio of the nickel foam conductive matrix to the hydrochloric acid solution is 1:(50–500), the ultrasonic treatment time of the nickel foam conductive matrix in the hydrochloric acid solution is 5–60 min, and the drying temperature is 20–150 °C. o C, drying time is 5~24 h.

[0011] Furthermore, in step 2, the vulcanizing agent used is one of sulfur powder, thiourea, sodium sulfide, sodium thiosulfate, mercaptoethanol, and potassium sulfide; the auxiliary agent is one of hydrazine hydrate, ethylenediamine, urea, methylamine, melamine, and ammonia water; the solvent is one of water, methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide; and the phosphating agent is one of red phosphorus, black phosphorus, white phosphorus, and yellow phosphorus. The mass ratio of vulcanizing agent: auxiliary agent: phosphating agent: solvent is 1:(0.1~10):(0.01~1):(1~100).

[0012] Furthermore, in step 3, the mass ratio of pretreated nickel foam NF to dispersion a is 1:(50~1000), and the hydrothermal temperature is 120~280°C. o C, hydrothermal time is 6~48 h; drying temperature is 20~150℃ o C, drying time is 1~24 h.

[0013] Further, in step 4, the aluminum salt used is one of aluminum nitrate, aluminum sulfate, and aluminum acetate; the solvent used is one of water, methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide; the mass ratio of aluminum salt to solvent is 1:(500~10000); the concentration of the KOH electrolyte is 0.5~5 mol / L; the mass ratio of added liquid b to KOH electrolyte is 1:(5~200); the mass ratio of catalyst precursor to mixed electrolyte is 1:(50~500); the potential used for anodic electrochemical oxidation reconstruction is 0.5~2.5 V vs RHE; the reconstruction time is 0.5~30 min; the mass ratio of water to catalyst precursor used in the water washing process is (200~2000):1; and the drying temperature is 20~150 °C. oC, drying time is 1~24 h.

[0014] The aforementioned P-NiS@(Al,Ni)OOH / NF core-shell catalyst can be used for the oxygen evolution reaction in water electrolysis.

[0015] The beneficial effects of this invention are as follows: This invention addresses the problems of excessively high overpotential and high cost of existing transition metal catalysts in alkaline OER reactions. By introducing aluminum, the electrochemical reconstruction process of the P-NiS catalyst is regulated, forming a P-NiS@(Al,Ni)OOH / NF core-shell catalyst. This promotes the formation of NiOOH as the true active site and oxygen vacancies, and generates substances that can promote OH- - The adsorbed aluminum vacancies exhibit excellent oxygen evolution performance in water electrolysis. This invention features a simple preparation process, inexpensive and readily available raw materials, superior performance, and potential for industrial application. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0017] Figure 1 The image shown is a transmission electron microscope (TEM) image of the P-NiS@(Al,Ni)OOH / NF core-shell catalyst S1 prepared in Example 1 of this invention, illustrating that the reconstruction process formed an amorphous layer and a core-shell structure.

[0018] Figure 2 The XRD patterns are those of the P-NiS@(Al,Ni)OOH / NF core-shell catalyst S1 prepared in Example 1 of the present invention and the catalyst D1 prepared in Comparative Example 1 without the addition of aluminum during reconstruction, indicating that AlOOH was introduced into catalyst S1.

[0019] Figure 3 XPS images of the P-NiS@(Al,Ni)OOH / NF core-shell catalyst S1 prepared in Example 1 of this invention and the catalyst D1 prepared in Comparative Example 1 without aluminum addition during reconstruction. Wherein, a) Al 2 p + Ni 3 p Spectrum; b) O 1 s The spectrum indicates that aluminum and oxygen vacancies were introduced into the prepared catalyst S1, while Ni... 3+ The presence of this indicates the formation of NiOOH. Detailed Implementation

[0020] The present invention will be described below with reference to specific embodiments. Those skilled in the art will understand that these are for illustrative purposes only and do not limit the scope of the invention in any way.

[0021] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 Prepare a 3 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 1.6 mm thick, into a beaker with 40 g of the 3 mol / L hydrochloric acid solution and sonicate for 15 min. Then, remove the acid-treated nickel foam, wash it with 200 mL of water, and dry it at 60°C. o C. Drying time was 10 h to obtain pretreated nickel foam NF with a mass of 0.136 g. 0.761 g of thiourea and 1.8 g of hydrazine hydrate were added to 10 g of water and stirred for 15 min. During stirring, 0.0465 g of red phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 inside the reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 200 °C. o C, the hydrothermal time was 24 h. After the hydrothermal process, the nickel foam with phosphorus-doped nickel sulfide was removed, washed, and then heated at 60°C. o The catalyst precursor was dried at C temperature for 10 h to obtain a precursor with a mass of 0.352 g. 0.024 g of aluminum nitrate was added to 100 g of water to prepare liquid b. Subsequently, 0.25 g of liquid b was added to 30 g of 1 mol / L KOH solution under stirring. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed at 1.7 V vs. RHE voltage for 3 min. Afterwards, it was washed with 100 g of water and dried at 60 °C. o The P-NiS@(Al,Ni)OOH / NF core-shell catalyst, denoted as S1, is obtained by drying at C for 10 h. The mass ratio of the P-NiS@(Al,Ni)OOH / NF core-shell structure to the nickel foam NF conductive matrix in the catalyst is 1:1.6.

[0024] Example 2 Prepare a 2 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 1.6 mm thick, into a beaker with 54 g of the 2 mol / L hydrochloric acid solution and sonicate for 30 min. Then, remove the acid-treated nickel foam, wash it with 220 mL of water, and dry it at 80°C. o C. Drying time was 8 h to obtain pretreated nickel foam NF with a mass of 0.136 g. 0.320 g of sulfur powder and 2.56 g of hydrazine hydrate were added to 10 g of water and stirred for 15 min. During stirring, 0.0256 g of white phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 within the lining of the hydrothermal reactor. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 200 °C. o C, the hydrothermal time was 18 hours. After the hydrothermal process, the nickel foam with phosphorus-doped nickel sulfide was removed, washed, and then heated at 70°C. o The catalyst precursor was dried at C for 12 h to obtain a precursor with a mass of 0.352 g. 0.024 g of aluminum nitrate was added to 144 g of ethanol to prepare liquid b. Subsequently, 0.5 g of liquid b was added to 30 g of 2 mol / L KOH solution under stirring. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed at 1.7 V vs. RHE for 3 min. Afterwards, it was washed with 120 g of water and dried at 60 °C. o The P-NiS@(Al,Ni)OOH / NF core-shell catalyst, denoted as S2, can be obtained by drying at C for 10 h. The mass ratio of the P-NiS@(Al,Ni)OOH / NF core-shell structure to the nickel foam NF conductive matrix in the catalyst is 1:1.8.

[0025] Example 3 Prepare a 2.5 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 1.7 mm thick, into a beaker with 48 g of the 2.5 mol / L hydrochloric acid solution and sonicate for 20 min. Then, remove the acid-treated nickel foam, wash it with 300 mL of water, and dry it at 65°C. oC. Drying time was 12 h to obtain pretreated nickel foam NF with a mass of 0.136 g. 0.761 g of thiourea and 6.1 g of ethylenediamine were added to 10 g of ethanol and stirred for 15 min. During stirring, 0.068 g of yellow phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 inside the reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 200 °C. o C, the hydrothermal time was 40 h. After the hydrothermal process, the phosphorus-doped nickel sulfide foam was removed, washed, and then heated at 63°C. o Drying at C for 14 h yielded a catalyst precursor with a mass of 0.342 g. 0.021 g of aluminum sulfate was added to 126 g of N,N-dimethylacetamide to prepare liquid b. Subsequently, 0.3 g of liquid b was added to 30 g of 1.5 mol / L KOH solution under stirring. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed for 3.5 min at 1.73 V vs. RHE voltage. Following washing with 400 g of water and drying at 75°C... o The P-NiS@(Al,Ni)OOH / NF core-shell catalyst, denoted as S3, is obtained by drying at C for 8 h. The mass ratio of the P-NiS@(Al,Ni)OOH / NF core-shell structure to the nickel foam NF conductive matrix in the catalyst is 1:1.5.

[0026] Example 4 Prepare a 3 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 1.6 mm thick, into a beaker with 42 g of the 3 mol / L hydrochloric acid solution and sonicate for 30 min. Then, remove the acid-treated nickel foam, wash it with 320 mL of water, and dry it at 65°C. o C. Drying time was 12 h to obtain pretreated nickel foam NF with a mass of 0.136 g. 0.784 g of sodium sulfide and 5.5 g of ethylenediamine were added to 10 g of methanol and stirred for 15 min. During stirring, 0.118 g of black phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 inside the reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 200 °C. o C, the hydrothermal time was 16 h. After the hydrothermal process, the nickel foam with phosphorus-doped nickel sulfide was removed, washed, and then heated at 40°C.o The catalyst precursor was dried at C temperature for 15 h to obtain a precursor with a mass of 0.366 g. 0.021 g of aluminum sulfate was added to 130 g of water to prepare liquid b. Subsequently, 0.3 g of liquid b was added to 30 g of 2 mol / L KOH solution under stirring. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed at 1.65 V vs. RHE voltage for 15 min. Afterwards, it was washed with 500 g of water and dried at 60 °C. o The P-NiS@(Al,Ni)OOH / NF core-shell catalyst, denoted as S4, was prepared by drying at C for 9 h. The mass ratio of the P-NiS@(Al,Ni)OOH / NF core-shell structure to the nickel foam NF conductive matrix in the catalyst was 1:4.2.

[0027] Example 5 Prepare a 3 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 2.0 mm thick, into a beaker with 73.2 g of the 3 mol / L hydrochloric acid solution and sonicate for 30 min. Then, remove the acid-treated nickel foam, wash it with 300 mL of water, and dry it at 63°C. o C. Drying time was 14 h to obtain pretreated nickel foam NF with a mass of 0.244 g. 1.10 g of potassium sulfide and 6.0 g of urea were added to 10 g of N,N-dimethylformamide and stirred for 15 min. During stirring, 0.055 g of white phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into the liquid a obtained in step 2 inside the reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 180°C. o C, the hydrothermal time was 40 h. After the hydrothermal process, the nickel foam with phosphorus-doped nickel sulfide was removed, washed, and then heated at 64 °C. o The catalyst precursor was dried at C for 8 h to obtain a precursor with a mass of 0.442 g. 0.012 g of aluminum acetate was added to 96 g of dimethyl sulfoxide to prepare liquid b. Subsequently, 0.35 g of liquid b was added to 30 g of 1.8 mol / L KOH solution under stirring. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed at 1.85 V vs. RHE for 1 min. Afterwards, it was washed with 300 g of water and dried at 66 °C. oThe P-NiS@(Al,Ni)OOH / NF core-shell catalyst, denoted as S5, is obtained by drying at C for 6 h. The mass ratio of the P-NiS@(Al,Ni)OOH / NF core-shell structure to the nickel foam NF conductive matrix in the catalyst is 1:1.2.

[0028] Example 6 Prepare a 3 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 1.6 mm thick, into a beaker with 60 g of the 3 mol / L hydrochloric acid solution and sonicate for 30 min. Then, remove the acid-treated nickel foam, wash it with 360 mL of water, and dry it at 80°C. o C. Drying time was 10 h to obtain pretreated nickel foam NF with a mass of 0.136 g. 0.781 g of mercaptoethanol and 5.5 g of melamine were added to 10 g of dimethyl sulfoxide and stirred for 15 min. During stirring, 0.118 g of yellow phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 inside the hydrothermal reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 220 °C. o C, the hydrothermal time was 16 h. After the hydrothermal process, the nickel foam with phosphorus-doped nickel sulfide was removed, washed, and then heated at 65°C. o The catalyst precursor was dried at C for 7 h to obtain a precursor with a mass of 0.352 g. 0.021 g of aluminum nitrate was added to 140 g of methanol to prepare liquid b. Subsequently, 0.3 g of liquid b was added to 36 g of 1 mol / L KOH solution under stirring. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed at 1.90 V vs. RHE for 20 min. Afterwards, the mixture was washed with 300 g of water and dried at 64 °C. o The P-NiS@(Al,Ni)OOH / NF core-shell catalyst, denoted as S6, is obtained by drying at C for 5 h. The mass ratio of the P-NiS@(Al,Ni)OOH / NF core-shell structure to the nickel foam NF conductive matrix in the catalyst is 1:0.8.

[0029] Example 7 Prepare a 3 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 1.8 mm thick, into a beaker with 67 g of the 3 mol / L hydrochloric acid solution and sonicate for 30 min. Then, remove the acid-treated nickel foam, wash it with 400 mL of water, and dry it at 62°C.o C. Drying time was 6 h to obtain pretreated nickel foam NF with a mass of 0.166 g. 0.761 g of thiourea and 6.1 g of ammonia were added to 10 g of ethanol and stirred for 15 min. During stirring, 0.118 g of black phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 inside the reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 200 °C. o C, the hydrothermal time was 12 h. After the hydrothermal process, the phosphorus-doped nickel sulfide foam was removed, washed, and then heated at 55°C. o The catalyst precursor was dried at C for 7 h to obtain a precursor with a mass of 0.363 g. 0.021 g of aluminum acetate was added to 125 g of N,N-dimethylformamide to prepare liquid b. Subsequently, 0.4 g of liquid b was added to 32 g of 1 mol / L KOH solution under stirring. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed for 1.5 min at 1.85 V vs. RHE voltage. Afterwards, the mixture was washed with 300 g of water and dried at 56 °C. o The P-NiS@(Al,Ni)OOH / NF core-shell catalyst, denoted as S7, can be obtained by drying at C for 8 h. The mass ratio of the P-NiS@(Al,Ni)OOH / NF core-shell structure to the nickel foam NF conductive matrix in the catalyst is 1:2.6.

[0030] Example 8 Prepare a 2.0 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercial nickel foam, each 1.6 mm thick, into a beaker with 60 g of the 2.0 mol / L hydrochloric acid solution and sonicate for 18 min. Then, remove the acid-treated nickel foam, wash it with 240 mL of water, and dry it at 64°C. o C. Drying time was 6 h to obtain pretreated nickel foam NF with a mass of 0.136 g. 1.581 g of sodium thiosulfate and 0.948 g of methylamine were added to 10 g of N,N-dimethylformamide and stirred for 15 min. During stirring, 0.316 g of black phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 inside the reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 200 °C. oC, the hydrothermal time was 30 h. After the hydrothermal process, the nickel foam with phosphorus-doped nickel sulfide was removed, washed, and then heated at 63°C. o The catalyst precursor was dried at C for 8 h to obtain a precursor with a mass of 0.352 g. 0.021 g of aluminum sulfate was added to 140 g of water to prepare liquid b. Subsequently, 0.32 g of liquid b was added to 30 g of 1 mol / L KOH solution with stirring. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed at 1.75 V vs. RHE for 6 min. Afterwards, it was washed with 300 g of water and dried at 70°C. o The P-NiS@(Al,Ni)OOH / NF core-shell catalyst, denoted as S8, is obtained by drying at C for 3 h. The mass ratio of the P-NiS@(Al,Ni)OOH / NF core-shell structure to the nickel foam NF conductive matrix in the catalyst is 1:1.7.

[0031] Comparative Example 1 Prepare a 3 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 1.6 mm thick, into a beaker with 40 g of the 3 mol / L hydrochloric acid solution and sonicate for 15 min. Then, remove the acid-treated nickel foam, wash it with 200 mL of water, and dry it at 60°C. o C. Drying time was 10 h to obtain pretreated nickel foam NF with a mass of 0.136 g. 0.761 g of thiourea and 1.8 g of hydrazine hydrate were added to 10 g of water and stirred for 15 min. During stirring, 0.0465 g of red phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 inside the reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 200 °C. o C, the hydrothermal time was 24 h. After the hydrothermal process, the nickel foam with phosphorus-doped nickel sulfide was removed, washed, and then heated at 60°C. o The catalyst precursor was dried at C for 10 h to obtain a precursor with a mass of 0.352 g. 30 g of 1 mol / L KOH solution was added. Using the catalyst precursor obtained in step 3 as the working electrode, a three-electrode system was formed with a graphite rod electrode and a mercury / mercury oxide electrode. Controlled anodic electrochemical oxidation reconstruction was performed at 1.7 V vs. RHE for 3 min. Subsequently, the precursor was washed with 100 g of water and dried at 60 °C. o The P-NiS@NiOOH / NF core-shell catalyst, denoted as D1, can be obtained by drying at C for 10 h.

[0032] Comparative Example 2 Prepare a 3 mol / L hydrochloric acid solution. Place four 1 cm × 1 cm pieces of commercially available nickel foam, each 1.6 mm thick, into a beaker with 40 g of the 3 mol / L hydrochloric acid solution and sonicate for 15 min. Then, remove the acid-treated nickel foam, wash it with 200 mL of water, and dry it at 60°C. o C. Drying time was 10 h to obtain pretreated nickel foam NF with a mass of 0.136 g. 0.761 g of thiourea and 1.8 g of hydrazine hydrate were added to 10 g of water and stirred for 15 min. During stirring, 0.0465 g of red phosphorus was added to obtain liquid a. Liquid a was transferred to the lining of a 30 mL hydrothermal reactor, and four pieces of pretreated nickel foam NF from step 1 were placed into liquid a obtained in step 2 inside the reactor lining. After sealing the hydrothermal reactor, it was placed in an oven for hydrothermal reaction at a temperature of 200 °C. o C, the hydrothermal time was 24 h. After the hydrothermal process, the nickel foam with phosphorus-doped nickel sulfide was removed, washed, and then heated at 60°C. o The P-NiS / NF catalyst, denoted as D2, can be obtained by drying at temperature C for 10 h.

[0033] Comparative Example 3 Add 2.61 g of hydrated ruthenium trichloride and 30 g of 1.0 M KOH solution to 100 g of deionized water, and then... o Stirring at C for 45 minutes, followed by centrifugation, washing, separation, and drying, then at 300°C. o RuO2 powder was obtained by calcining at C for 3 hours and then dispersed in a mixed solution of 0.49 g of water and ethanol. 0.01 g of Nafion solution was then added to the solution, and the mixture was sonicated for 30 minutes until the catalyst was uniformly dispersed. A suitable amount of the catalyst dispersion was pipetted onto the surface of nickel foam and dried to obtain the prepared RuO2 / NF, denoted as D3.

[0034] Example 9 The prepared P-NiS@(Al,Ni)OOH core-shell catalyst was used as the working electrode, a graphite rod as the counter electrode, and a mercury-mercury oxide electrode as the reference electrode. It was placed in an electrolytic cell, and CV activation and LSV measurements were performed within the voltage range of 1.02–1.72 V vs. RHE. As shown in the table, the prepared electrocatalyst exhibited good performance at 10 mA cm⁻¹. -2 It exhibits a low overpotential at current density and shows good potential. Comparing S1 with D1, D2, and D3, it can be seen that adding Al during the reconstruction process... 3+This significantly improved the OER performance of the catalyst.

[0035] Table 1. Catalytic performance of the catalysts prepared in the above examples in alkaline OER reactions.

Claims

1. A P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution, characterized in that, The P-NiS@(Al,Ni)OOH / NF core-shell catalyst is a nickel foam self-supporting catalyst, comprising a nickel foam NF conductive matrix and a P-NiS@(Al,Ni)OOH core-shell structure grown in situ on the nickel foam NF conductive matrix. The P-NiS@(Al,Ni)OOH core-shell structure includes a P-NiS nanorod-shaped core layer structure and a shell layer structure composed of AlOOH and amorphous NiOOH located outside the core layer structure. The outer shell layer structure is rich in oxygen vacancies, aluminum metal vacancies, and high-valence nickel species.

2. The P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution according to claim 1, characterized in that, In the electrocatalytic oxygen evolution P-NiS@(Al,Ni)OOH / NF core-shell catalyst, the mass ratio of the P-NiS@(Al,Ni)OOH core-shell structure to the nickel foam NF conductive matrix is ​​1:(0.4~10).

3. A method for preparing a P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution as described in any one of claims 1-2, characterized in that, Includes the following steps: Step 1: Prepare a hydrochloric acid solution, mix the hydrochloric acid solution with the conductive nickel foam matrix and sonicate it, then wash and dry to obtain pretreated nickel foam NF; Step 2: Add the vulcanizing agent and additives to the solvent and stir to prepare a solution. While stirring, add the phosphating agent to obtain liquid a. Step 3: Transfer liquid a into a hydrothermal reactor, and put the pretreated nickel foam NF from step 1 into liquid a obtained in step 2 in the hydrothermal reactor. After sealing the hydrothermal reactor, perform hydrothermal treatment. After hydrothermal treatment, take out the nickel foam with phosphorus-doped nickel sulfide grown, wash and dry it to obtain the catalyst precursor. Step 4: Add aluminum salt to solvent to obtain liquid b. Then, under stirring, add liquid b to KOH electrolyte to form a mixed electrolyte. Use the catalyst precursor obtained in step 3 as working electrode, and form a three-electrode system with graphite rod electrode and mercury / mercury oxide electrode. After controlled anodic electrochemical oxidation reconstruction, and then washing and drying, the P-NiS@(Al,Ni)OOH / NF core-shell catalyst can be obtained.

4. The method for preparing a P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution according to claim 3, characterized in that, In step 1, the concentration of the hydrochloric acid solution is 0.5–3 mol / L. The size of the nickel foam conductive matrix is ​​1 cm × 1 cm, and the thickness is 0.5–3 mm. The mass ratio of the nickel foam conductive matrix to the hydrochloric acid solution is 1:(50–500). The ultrasonic treatment time of the nickel foam conductive matrix in the hydrochloric acid solution is 5–60 min, and the drying temperature is 20–150 °C. o C, drying time is 5~24h.

5. The method for preparing a P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution according to claim 3, characterized in that, In step 2, the vulcanizing agent used is one of sulfur powder, thiourea, sodium sulfide, sodium thiosulfate, mercaptoethanol, and potassium sulfide; the auxiliary agent is one of hydrazine hydrate, ethylenediamine, urea, methylamine, melamine, and ammonia water; the solvent is one of water, methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide; and the phosphating agent is one of red phosphorus, black phosphorus, white phosphorus, and yellow phosphorus. The mass ratio of vulcanizing agent: auxiliary agent: phosphating agent: solvent is 1:(0.1~10):(0.01~1):(1~100).

6. The method for preparing a P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution according to claim 3, characterized in that, In step 3, the mass ratio of pretreated nickel foam NF to dispersion a is 1:(50~1000), and the hydrothermal temperature is 120~280°C. o C, hydrothermal time is 6~48 h; drying temperature is 20~150℃ o C, drying time is 1~24h.

7. The method for preparing a P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution according to claim 3, characterized in that, In step 4, the aluminum salt used is one of aluminum nitrate, aluminum sulfate, or aluminum acetate; the solvent used is one of water, methanol, ethanol, dimethyl sulfoxide, or N,N-dimethylformamide; the mass ratio of aluminum salt to solvent is 1:(500~10000); the concentration of the KOH electrolyte is 0.5~5 mol / L; the mass ratio of added liquid b to KOH electrolyte is 1:(5~200); the mass ratio of catalyst precursor to mixed electrolyte is 1:(50~500); the potential used for anodic electrochemical oxidation reconstruction is 0.5~2.5 V vs RHE; the reconstruction time is 0.5~30 min; the mass ratio of water to catalyst precursor used in the water washing process is (200~2000):1; and the drying temperature is 20~150 °C. o C, drying time is 1~24 h.

8. The application of the P-NiS@(Al,Ni)OOH / NF core-shell catalyst for electrocatalytic oxygen evolution as described in any one of claims 1-2, or the P-NiS@(Al,Ni)OOH / NF core-shell catalyst prepared by any one of claims 3-7, characterized in that, Used in the oxygen evolution reaction of water electrolysis.

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