A cerium dioxide-transition metal phosphide composite self-supporting electrode material and its preparation method and application

Abstract

The present invention relates to the technical field of electrolytic water catalysts, and in particular to a cerium dioxide-transition metal phosphide composite self-supporting electrode material and its preparation method and application. The preparation method includes (1) using nickel foam as a substrate, dispersing nickel salt, cobalt salt, cerium salt, and organic ligand in a solvent for hydrothermal reaction, and obtaining a nickel foam with a ternary metal organic framework compound precursor grown on the surface; (2) placing sodium hypophosphite on the upwind side of a tube furnace, placing the nickel foam sample obtained in step (1) on the downwind side of the tube furnace, sealing the tube furnace and making the tube furnace oxygen-free, introducing inert gas, heating, and cooling after insulation. The present invention uses the ternary metal organic framework compound grown in situ on the nickel foam as a precursor to prepare a cerium dioxide-transition metal phosphide composite material with a unique morphological structure, further optimizes the overall catalytic activity of the catalyst, has good commercial application prospects, and is suitable for promotion and commercial production.

Description

Technical Field

[0001] The present invention relates to the technical field of water electrolysis catalysts, and in particular to a cerium dioxide-transition metal phosphide composite self-supporting electrode material, a preparation method and applications thereof. Background Art

[0002] For a long time, the rapid consumption of fossil fuels has brought about problems such as the greenhouse effect, environmental pollution, and energy shortages, prompting humanity to reduce its use of non-renewable resources and actively develop efficient, renewable, clean energy. Hydrogen energy has become a promising energy source due to its wide availability, high combustion energy density, high energy conversion efficiency, and clean and renewable properties. Hydrogen production by water electrolysis stands out among various hydrogen production technologies. The water electrolysis process typically consists of two half-reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Due to its high energy conversion efficiency, zero carbon emissions, and simple process flow, it is currently an ideal way to convert renewable energy into hydrogen energy. Oxygen produced by the OER is also an important reaction gas. In addition, the sluggish kinetics of the OER are also one of the factors affecting the performance of hydrogen evolution.

[0003] Currently, the best-performing water electrolysis catalysts are those made from precious metals, such as platinum, ruthenium, and iridium. However, these metals are subject to high cost, limited Earth reserves, and poor stability. Transition metal phosphides are often considered ideal alternatives to precious metal catalysts due to their suitable electronic configuration, metallic properties, and cost-effectiveness. In particular, transition bimetallic phosphides exhibit excellent overall water splitting activity due to interatomic synergy. However, their poor electrical conductivity and catalytic activity hinder their further development and application. Combining them with another oxide to form a composite material is one effective strategy to improve the conductivity and activity of the material. Furthermore, in situ synthesis of the material on a self-supporting substrate avoids the use of organic binders, improves charge transfer between the catalyst and the electrode, and enhances the catalytic activity and stability of the material, which has far-reaching significance for promoting the industrialization of clean energy. Summary of the Invention

[0004] In response to the technical problem of poor conductivity and catalytic activity of transition metal phosphides, the present invention provides a cerium dioxide-transition metal phosphide composite self-supporting electrode material, a preparation method and application thereof, and a ternary metal organic framework compound in situ grown on nickel foam is used as a precursor to prepare a cerium dioxide-transition metal phosphide composite material with a unique morphological structure, further optimizing the overall catalytic activity of the catalyst. It is used as a bifunctional catalyst in full water splitting applications, and its full water splitting performance is superior to that of commercial catalysts, realizing low-energy electrolysis of water to produce clean energy. It has good commercial application prospects and is suitable for promotion and commercial production.

[0005] In a first aspect, the present invention provides a method for preparing a ceria-transition metal phosphide composite self-supporting electrode material, comprising the following steps:

[0006] (1) Preparation of metal-organic framework compound precursors

[0007] Using nickel foam as a substrate, cerium salt, nickel salt, cobalt salt, and organic ligand are dispersed in a solvent and subjected to a hydrothermal reaction to obtain nickel foam with a ternary metal organic framework compound precursor grown on the surface;

[0008] (2) Preparation of Cerium Dioxide-Transition Metal Phosphide Composite Self-Supporting Electrode Materials

[0009] Sodium hypophosphite is placed at the upwind side of a tube furnace, and nickel foam with a ternary metal organic framework compound precursor grown on its surface is placed at the downwind side of the tube furnace. The tube furnace is sealed and oxygen-free, an inert gas is introduced, and then the temperature is increased, maintained, and then cooled to obtain a cerium dioxide-transition metal phosphide composite self-supporting electrode material grown in situ on the nickel foam.

[0010] Furthermore, step (1) is specifically as follows: using a hydrothermal growth method, a certain amount of nickel salt, cobalt salt, cerium salt, and organic ligand are weighed, dispersed in a certain volume of solvent, stirred and dissolved uniformly, and transferred to a high-pressure reactor containing pretreated nickel foam. After encapsulation, the shell is transferred to a constant temperature oven, kept for a certain period of time, and then naturally cooled. After the reaction is completed, the product is removed from the reactor, repeatedly rinsed with ultrapure water and anhydrous ethanol, and dried in a vacuum oven for a certain period of time to obtain a nickel foam with a ternary metal organic framework compound precursor grown on the surface.

[0011] Furthermore, in step (1), the cerium salt is one or more of cerium chloride, cerium nitrate and ammonium cerium nitrate, the nickel salt is one or more of nickel nitrate, nickel acetate, nickel chloride and nickel sulfate, the cobalt salt is one or more of cobalt nitrate, cobalt acetate and cobalt chloride; and the organic ligand is one or more of trimesic acid, terephthalic acid, 2-aminoterephthalic acid and 2,4-dihydroxyterephthalic acid.

[0012] Furthermore, in step (1), the amount of cerium salt added is 0.01-1 mmol, the amount of nickel salt added is 0.05-0.3 mmol, the amount of cobalt salt added is 0.05-0.7 mmol, the amount of organic ligand added is 0.1-1 mmol, and the volume of the solvent is 25-50 mL.

[0013] Furthermore, in step (1), the solvent is one or more of N,N-dimethylformamide, ultrapure water, anhydrous ethanol and ethylene glycol.

[0014] Furthermore, in step (1), the temperature of the hydrothermal reaction is 100-140° C., and the time of the hydrothermal reaction is 6-24 h.

[0015] Furthermore, step (1) also includes pre-treating the nickel foam by first ultrasonically cleaning it with a hydrochloric acid solution for 20-30 minutes, then ultrasonically cleaning it with ultrapure water for 5-10 minutes, and finally treating it with an anhydrous ethanol solution for 5-10 minutes to remove grease and an oxide layer on the surface of the nickel foam.

[0016] Furthermore, step (2) is specifically as follows: using an in-situ low-temperature phosphating method, a certain amount of sodium hypophosphite is placed at the upwind side of a tube furnace, the nickel foam sample obtained in step (1) is placed at the downwind side of the tube furnace, the tube furnace is sealed and oxygen-free, and then an inert gas is introduced and the temperature is raised to a certain temperature at a certain heating rate, maintained for a certain period of time, and then cooled to room temperature at a certain cooling rate to obtain a cerium dioxide-transition metal phosphide composite self-supporting electrode material grown in situ on the nickel foam.

[0017] Furthermore, in step (2), the inert gas is argon or nitrogen.

[0018] Furthermore, in step (2), the amount of sodium hypophosphite added is 0.5-1.5 g / 11.25 cm 3 The nickel foam substrate, that is, for a nickel foam substrate with a specification of 3 cm in length×2.5 cm in width×1.5 mm in thickness, the amount of sodium hypophosphite corresponding to each piece of the nickel foam substrate is 0.5-1.5 g.

[0019] Furthermore, in step (2), the temperature is raised to 300-400°C at a heating rate of 1-5°C / min, maintained for 0.5-3h, and then cooled to room temperature at a cooling rate of 1-5°C / min.

[0020] In a second aspect, the present invention provides a ceria-transition metal phosphide composite self-supporting electrode material prepared by the above-mentioned preparation method.

[0021] In a third aspect, the present invention provides an application of the above-mentioned ceria-transition metal phosphide composite self-supporting electrode material as a water electrolysis catalyst.

[0022] The beneficial effects of the present invention are:

[0023] 1. The cerium dioxide-transition metal phosphide composite self-supporting electrode material prepared by the present invention uses low-cost raw materials, has few preparation steps, is simple to operate, uses cheap and readily available equipment, has high reproducibility, and is easy to scale up for production.

[0024] 2. The ceria-transition metal phosphide composite self-supporting electrode material prepared by the present invention exhibits excellent hydrogen evolution performance in alkaline, neutral, and acidic electrolytes, operating stably for 100 hours in all of these solutions, demonstrating excellent stability. In particular, under alkaline conditions, it exhibits excellent oxygen evolution performance in water electrolysis and good overall water splitting catalytic performance, outperforming commercial catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0026] Figure 1 3 is a scanning electron microscope image of the self-supporting electrode material prepared in Example 1.

[0027] Figure 2 This is a scanning electron microscope image of the self-supporting electrode material prepared in Example 2.

[0028] Figure 3 This is a scanning electron microscope image of the self-supporting electrode material prepared in Example 3.

[0029] Figure 4 It is a linear sweep voltammetry curve of the hydrogen evolution performance of the self-supporting electrode materials prepared in Examples 1 to 3 and Comparative Example 1 in the electrolysis of water in an alkaline electrolyte.

[0030] Figure 5 It is a linear sweep voltammetry curve of the hydrogen evolution performance of the self-supporting electrode materials prepared in Examples 1 to 3 and Comparative Example 1 in the electrolysis of water in a neutral electrolyte.

[0031] Figure 6 It is a linear sweep voltammetry curve of the hydrogen evolution performance of the self-supporting electrode materials prepared in Examples 1 to 3 and Comparative Example 1 in the electrolysis of water in an acidic electrolyte.

[0032] Figure 7 This is a current density-time stability test curve of the self-supporting electrode material prepared in Example 1 during water electrolysis and hydrogen evolution in an alkaline electrolyte.

[0033] Figure 8 This is a current density-time stability test curve of the self-supporting electrode material prepared in Example 1 during water electrolysis and hydrogen evolution in a neutral electrolyte.

[0034] Figure 9 This is a current density-time stability test curve of the self-supporting electrode material prepared in Example 1 during water electrolysis and hydrogen evolution in an acidic electrolyte.

[0035] Figure 10 It is a linear sweep voltammetry curve of the oxygen evolution performance of the self-supporting electrode materials prepared in Examples 1 to 3 and Comparative Example 1 in the electrolysis of water in an alkaline electrolyte.

[0036] Figure 11 This is a current density-time stability test curve of the self-supporting electrode material prepared in Example 1 during water electrolysis and oxygen evolution in an alkaline electrolyte.

[0037] Figure 12 It is a linear sweep voltammetry curve of the self-supporting electrode materials prepared in Examples 1 to 3 and Comparative Example 1 and the purchased commercial electrode materials in the complete water decomposition performance in alkaline electrolyte.

[0038] Figure 13 This is a current density-time stability test curve of the self-supporting electrode material prepared in Example 1 in the complete water splitting in alkaline electrolyte. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0040] Example 1

[0041] A ceria-transition metal phosphide composite self-supporting electrode material is prepared by the following preparation method:

[0042] (1) Nickel foam (3 cm long × 2.5 cm wide × 1.5 mm thick) was placed in a hydrochloric acid solution consisting of 5 mL concentrated hydrochloric acid and 55 mL ultrapure water. After ultrasonic cleaning for 20 min, it was rinsed with ultrapure water until neutral. The nickel foam was then placed in ultrapure water and anhydrous ethanol, respectively, and ultrasonically treated for 5 min each to obtain pretreated nickel foam.

[0043] 0.25 mmol of cerium nitrate, 0.11 mmol of nickel chloride, 0.34 mmol of cobalt nitrate, and 0.45 mmol of terephthalic acid were weighed and dispersed in a solvent containing 36 mL of N,N-dimethylformamide, 3.6 mL of ultrapure water, and 3.6 mL of anhydrous ethanol. The mixture was stirred and dissolved uniformly. The mixture was then transferred to an autoclave containing the pretreated nickel foam. After encapsulation, the foam was placed in a 120°C constant-temperature oven for 12 hours, then cooled naturally. After the reaction was complete, the product was removed from the autoclave, rinsed repeatedly with ultrapure water and anhydrous ethanol, and dried in a vacuum oven at 60°C for 12 hours to obtain a nickel foam with the ternary metal-organic framework precursor grown on its surface.

[0044] (2) 1 g of sodium hypophosphite was placed at the upwind side of a tube furnace, and the nickel foam sample obtained in step (1) was placed at the downwind side of the tube furnace. The tube furnace was sealed and oxygen-free, and then nitrogen was introduced. The temperature was raised to 350° C. at a heating rate of 3° C. / min, maintained for 2 h, and then cooled to room temperature at a cooling rate of 3° C. / min to obtain a cerium dioxide-transition metal phosphide composite self-supporting electrode material (hereinafter referred to as the self-supporting electrode material) in situ grown on nickel foam. Figure 1 As shown, the self-supporting electrode material grows uniformly and has a unique morphology structure.

[0045] Example 2

[0046] A ceria-transition metal phosphide composite self-supporting electrode material is prepared by the following preparation method:

[0047] (1) Nickel foam (3 cm long × 2.5 cm wide × 1.5 mm thick) was placed in a hydrochloric acid solution consisting of 5 mL concentrated hydrochloric acid and 55 mL ultrapure water. After ultrasonic cleaning for 20 min, it was rinsed with ultrapure water until neutral. The nickel foam was then placed in ultrapure water and anhydrous ethanol, respectively, and ultrasonically treated for 5 min each to obtain pretreated nickel foam.

[0048] 0.1 mmol of cerium nitrate, 0.11 mmol of nickel chloride, 0.34 mmol of cobalt nitrate, and 0.45 mmol of terephthalic acid were weighed and dispersed in a solvent containing 36 mL of N,N-dimethylformamide, 3.6 mL of ultrapure water, and 3.6 mL of anhydrous ethanol. The mixture was stirred and dissolved uniformly. The mixture was then transferred to an autoclave containing the pretreated nickel foam. After encapsulation, the foam was placed in a 120°C constant-temperature oven for 12 hours, then cooled naturally. After the reaction was complete, the product was removed from the autoclave, rinsed repeatedly with ultrapure water and anhydrous ethanol, and dried in a vacuum oven at 60°C for 12 hours to obtain a nickel foam with a binary metal-organic framework precursor grown on its surface.

[0049] (2) 1 g of sodium hypophosphite is placed at the upwind side of a tube furnace, and the nickel foam sample obtained in step (1) is placed at the downwind side of the tube furnace. The tube furnace is sealed and oxygen-free, and then nitrogen is introduced. The temperature is raised to 350°C at a heating rate of 3°C / min, maintained for 2 hours, and then cooled to room temperature at a cooling rate of 3°C / min to obtain a transition metal phosphide composite self-supporting electrode material grown in situ on the nickel foam.

[0050] Example 3

[0051] A ceria-transition metal phosphide composite self-supporting electrode material is prepared by the following preparation method:

[0052] (1) Nickel foam (3 cm long × 2.5 cm wide × 1.5 mm thick) was placed in a hydrochloric acid solution consisting of 5 mL concentrated hydrochloric acid and 55 mL ultrapure water. After ultrasonic cleaning for 20 min, it was rinsed with ultrapure water until neutral. The nickel foam was then placed in ultrapure water and anhydrous ethanol, respectively, and ultrasonically treated for 5 min each to obtain pretreated nickel foam.

[0053] 0.4 mmol of cerium nitrate, 0.11 mmol of nickel chloride, 0.34 mmol of cobalt nitrate, and 0.45 mmol of terephthalic acid were weighed and dispersed in a solvent containing 36 mL of N,N-dimethylformamide, 3.6 mL of ultrapure water, and 3.6 mL of anhydrous ethanol. The mixture was stirred and dissolved uniformly. The mixture was then transferred to an autoclave containing the pretreated nickel foam. After encapsulation, the foam was placed in a 120°C constant-temperature oven for 12 hours, then cooled naturally. After the reaction was complete, the product was removed from the autoclave, rinsed repeatedly with ultrapure water and anhydrous ethanol, and dried in a vacuum oven at 60°C for 12 hours to obtain a nickel foam with a binary metal-organic framework precursor grown on its surface.

[0054] (2) 1 g of sodium hypophosphite was placed at the upwind side of a tube furnace, and the nickel foam sample obtained in step (1) was placed at the downwind side of the tube furnace. The tube furnace was sealed and oxygen-free, and then nitrogen was introduced. The temperature was raised to 350° C. at a heating rate of 3° C. / min, maintained for 2 h, and then cooled to room temperature at a cooling rate of 3° C. / min to obtain a transition metal phosphide composite self-supporting electrode material (hereinafter referred to as the self-supporting electrode material) grown in situ on the nickel foam.

[0055] Comparative Example 1

[0056] A self-supporting transition metal phosphide composite water electrolysis electrode catalyst material is prepared by the following preparation method:

[0057] (1) The nickel foam was placed in a hydrochloric acid solution consisting of 5 mL of concentrated hydrochloric acid and 55 mL of ultrapure water, ultrasonically cleaned for 20 minutes, and then rinsed with ultrapure water until neutral. The nickel foam was then placed in ultrapure water and anhydrous ethanol, respectively, and ultrasonically treated for 5 minutes each to obtain pretreated nickel foam.

[0058] 0.11 mmol of nickel chloride, 0.34 mmol of cobalt nitrate, and 0.45 mmol of terephthalic acid were weighed and dispersed in a solvent containing 36 mL of N,N-dimethylformamide, 3.6 mL of ultrapure water, and 3.6 mL of anhydrous ethanol. The mixture was stirred and dissolved uniformly. The mixture was then transferred to an autoclave containing the pretreated nickel foam. After encapsulation, the foam was placed in a 120°C constant-temperature oven for 12 hours and then allowed to cool naturally. After the reaction was completed, the product was removed from the autoclave, rinsed repeatedly with ultrapure water and anhydrous ethanol, and dried in a vacuum oven at 60°C for 12 hours to obtain a nickel foam with the binary metal-organic framework precursor grown on its surface.

[0059] (2) 1 g of sodium hypophosphite was placed at the upwind side of a tube furnace, and the nickel foam sample obtained in step (1) was placed at the downwind side of the tube furnace. The tube furnace was sealed and oxygen-free, and then nitrogen was introduced. The temperature was raised to 350° C. at a heating rate of 3° C. / min, maintained for 2 h, and then cooled to room temperature at a cooling rate of 3° C. / min to obtain a transition metal phosphide composite self-supporting electrode material (hereinafter referred to as the self-supporting electrode material) grown in situ on the nickel foam.

[0060] Example 4

[0061] The self-supporting electrode materials prepared in Examples 1 to 3 and Comparative Example 1 were respectively used as working electrodes, a saturated silver-silver chloride electrode was used as a reference electrode, a graphite rod electrode was used as a counter electrode, and an alkaline solution (a potassium hydroxide solution with a concentration of 1.0 mol / L), a neutral solution (a phosphate buffered saline solution with a concentration of 1.0 mol / L), and an acidic solution (a sulfuric acid solution with a concentration of 0.5 mol / L) were used as electrolytes, respectively. Electrolytic cells were assembled to analyze the hydrogen evolution performance of the self-supporting electrode materials in water electrolysis.

[0062] like Figure 4 As shown, compared with Examples 2, 3 and Comparative Example 1, at the same current density, the voltage required for the self-supporting electrode material prepared in Example 1 is smaller, indicating that the self-supporting electrode material prepared in Example 1 has more superior water electrolysis and hydrogen evolution performance in alkaline electrolyte, further proving that the introduction of oxides can significantly improve the water electrolysis and hydrogen evolution performance of the material in alkaline electrolyte.

[0063] like Figure 5As shown, compared with Examples 2, 3 and Comparative Example 1, at the same current density, the voltage required for the self-supporting electrode material prepared in Example 1 is smaller, indicating that the self-supporting electrode material prepared in Example 1 has more superior water electrolysis and hydrogen evolution performance in a neutral electrolyte, further proving that the introduction of oxides can significantly improve the water electrolysis and hydrogen evolution performance of the material in a neutral electrolyte.

[0064] like Figure 6 As shown, compared with Examples 2 and 3, at the same current density, the voltage required for the self-supporting electrode material prepared in Example 1 is smaller, indicating that the self-supporting electrode material prepared in Example 1 has more superior water electrolysis and hydrogen evolution performance in acidic electrolyte, further proving that the introduction of oxides can significantly improve the water electrolysis and hydrogen evolution performance of the material in acidic electrolyte.

[0065] Combine Figure 4 、 Figure 5 and Figure 6 It can be found that the self-supporting electrode material prepared in Example 1 has good water electrolysis and hydrogen evolution performance in alkaline, neutral and acidic electrolytes, indicating that the material is a good water electrolysis and hydrogen evolution catalyst material, exhibits a wide range of action, and has good application prospects.

[0066] Combine Figure 7 、 Figure 8 and Figure 9 It can be found that the self-supporting electrode material prepared in Example 1 can maintain a certain current density and operate stably for 100 hours in alkaline, neutral and acidic electrolytes, indicating that the material has good electrolytic water hydrogen evolution stability and corrosion resistance in alkaline, neutral and acidic electrolytes.

[0067] Example 5

[0068] The self-supporting electrode materials prepared in Examples 1 to 3 and Comparative Example 1 were respectively used as working electrodes, a saturated silver-silver chloride electrode was used as a reference electrode, a graphite rod electrode was used as a counter electrode, and an alkaline solution (potassium hydroxide solution with a concentration of 1.0 mol / L) was used as an electrolyte to assemble an electrolytic cell, and the water electrolysis and oxygen evolution performance of the self-supporting electrode material was analyzed.

[0069] like Figure 10 As shown, compared with Examples 2, 3 and Comparative Example 1, at the same current density, the voltage required for the self-supporting electrode material prepared in Example 1 is smaller, indicating that the self-supporting electrode material prepared in Example 1 has more superior water electrolysis and oxygen evolution performance in alkaline electrolyte, further proving that the introduction of oxides can significantly improve the water electrolysis and oxygen evolution performance of the material in alkaline electrolyte.

[0070] like Figure 11As shown in Figure 1, the self-supporting electrode material prepared in Example 1 can maintain a certain current density and operate stably for 100 hours in alkaline electrolyte, indicating that the material has good electrolytic water oxygen evolution stability and corrosion resistance in alkaline electrolyte. Figure 10 It can be seen that the self-supporting electrode material prepared in Example 1 is a good catalyst material for oxygen evolution by water electrolysis.

[0071] Example 6

[0072] Since the self-supporting electrode material prepared in Example 1 exhibits good hydrogen and oxygen evolution performance in water electrolysis, it shows that the material is a bifunctional catalyst with the potential to drive the complete water splitting reaction. Therefore, the self-supporting electrode material prepared in Example 1 was assembled into an electrolytic cell as a cathode and an anode, and the complete water splitting performance of the electrode material was tested using a two-electrode system. The electrolyte was an alkaline solution (potassium hydroxide solution with a concentration of 1.0 mol / L), and the self-supporting electrode materials prepared in Examples 2 and 3, Comparative Example 1, and purchased commercial catalyst materials (the commercial hydrogen evolution catalyst was a platinum carbon catalyst (20 wt%), purchased from Shanghai Hesen Electric Co., Ltd.; the commercial oxygen evolution catalyst was iridium oxide (99.9%), purchased from Sigma-Aldrich (Shanghai) Co., Ltd.) were used as controls.

[0073] like Figure 12 As shown, as the applied voltage increases, the current density of the electrolytic cell composed of Example 1 also increases, indicating that the self-supporting electrode material prepared in Example 1 is indeed a catalyst material with full water decomposition performance. Compared with Examples 2, 3 and Comparative Example 1, at the same current density, the voltage required for the self-supporting electrode material prepared in Example 1 is smaller, indicating that the self-supporting electrode material prepared in Example 1 has more superior full water decomposition performance in alkaline electrolyte, further proving that the introduction of oxides can significantly improve the full water decomposition performance of the material in alkaline electrolyte. Compared with the purchased commercial catalyst material, at the same current density, the voltage required for the self-supporting electrode material prepared in Example 1 is smaller, indicating that the self-supporting electrode material prepared in Example 1 is a good full water decomposition catalyst material, and the full water decomposition performance exceeds the full water decomposition performance of the commercial catalyst.

[0074] like Figure 13 As shown in Figure 1, the self-supporting electrode material prepared in Example 1 can maintain a certain current density and operate stably for 100 hours in alkaline electrolyte, indicating that the material has good full water decomposition stability and corrosion resistance in alkaline electrolyte. Figure 12 , further proving that the self-supporting electrode material prepared in Example 1 is a water electrolysis catalyst with good catalytic performance and stability and great commercial application value.

[0075] Although the present invention has been described in detail with reference to the accompanying drawings and in conjunction with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be easily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A method for preparing a ceria-transition metal phosphide composite self-supporting electrode material, characterized in that: The steps include: (1) Using nickel foam as a substrate, cerium salt, nickel salt, cobalt salt, and organic ligand are dispersed in a solvent and subjected to a hydrothermal reaction to obtain nickel foam with a ternary metal organic framework compound precursor grown on the surface; The amount of cerium salt added is 0.01-1 mmol, the amount of nickel salt added is 0.05-0.3 mmol, the amount of cobalt salt added is 0.05-0.7 mmol, the amount of organic ligand added is 0.1-1 mmol, and the volume of the solvent is 25-50 mL; (2) Sodium hypophosphite is placed at the upwind side of a tube furnace, and nickel foam with a ternary metal organic framework compound precursor grown on its surface is placed at the downwind side of the tube furnace. The tube furnace is sealed and oxygen-free, an inert gas is introduced, and then the temperature is increased, kept warm, and then cooled to obtain a cerium dioxide-transition metal phosphide composite self-supporting electrode material grown in situ on the nickel foam.

2. The preparation method according to claim 1, wherein In step (1), the cerium salt is one or more of cerium chloride, cerium nitrate and ammonium cerium nitrate; the nickel salt is one or more of nickel nitrate, nickel acetate, nickel chloride and nickel sulfate; the cobalt salt is one or more of cobalt nitrate, cobalt acetate and cobalt chloride; and the organic ligand is one or more of trimesic acid, terephthalic acid, 2-aminoterephthalic acid and 2,4-dihydroxyterephthalic acid.

3. The preparation method according to claim 1, wherein In step (1), the solvent is one or more of N,N-dimethylformamide, ultrapure water, anhydrous ethanol and ethylene glycol.

4. The preparation method according to claim 1, wherein In step (1), the temperature of the hydrothermal reaction is 100-140° C., and the time of the hydrothermal reaction is 6-24 h.

5. The preparation method according to claim 1, wherein Step (1) also includes pre-treating the nickel foam by first ultrasonically cleaning it with a hydrochloric acid solution for 20-30 minutes, then ultrasonically cleaning it with ultrapure water for 5-10 minutes, and finally treating it with an anhydrous ethanol solution for 5-10 minutes.

6. The preparation method according to claim 1, wherein In step (2), the amount of sodium hypophosphite added is 0.5-1.5g / 1.125cm 3 Nickel foam substrate.

7. The preparation method according to claim 1, wherein In step (2), the temperature is raised to 300-400°C at a heating rate of 1-5°C / min, maintained for 0.5-3h, and then cooled to room temperature at a cooling rate of 1-5°C / min.

8. A ceria-transition metal phosphide composite self-supporting electrode material prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the cerium dioxide-transition metal phosphide composite self-supporting electrode material as claimed in claim 8 as a water electrolysis catalyst.

Images