A self-supporting transition metal hydroxide or oxide composite material, a preparation method and application thereof in electrocatalytic oxygen evolution
By loading transition metal hydroxide/oxide composite materials on nickel foam, the problems of scarcity of precious metal catalysts and low efficiency of oxygen evolution reaction are solved, and a cheap and efficient electrocatalytic oxygen evolution effect is achieved, which has industrial application value.
Patent Information
- Application Number
- CN202211532719.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-02
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2042-12-02
AI Technical Summary
The scarcity and high cost of existing precious metal catalysts limit the industrial application of oxygen production by water electrolysis, and the slow four-electron transfer reaction of the oxygen evolution reaction leads to low reaction efficiency.
Transition metal hydroxides/oxides were loaded on nickel foam using hydrothermal calcination and three-electrode system electrodeposition technology to prepare a self-supporting transition metal hydroxide/oxide composite material NiFe-LDH/CuCo2O4/NF for electrocatalytic oxygen evolution.
It achieves cheap and efficient electrocatalytic oxygen evolution performance, reduces overpotential, improves catalyst stability and catalytic activity, and has potential for industrial application.
Smart Images
Figure CN115710726B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of electrocatalytic material preparation and oxygen evolution application, and in particular to a self-supporting transition metal hydroxide or oxide composite material, a preparation method and application of the same for electrocatalytic oxygen evolution. Background Art
[0002] Humanity faces increasingly severe environmental challenges today. The use of fossil fuels produces large amounts of polluting gases, leading to a growing greenhouse effect. Furthermore, fossil fuels are non-renewable resources, exacerbating resource shortages. To alleviate pressure on the natural environment and resources, the development of clean, renewable energy sources is imperative. Water is Earth's most abundant resource, and hydrogen produced by water decomposition is an excellent clean energy source. Oxygen is also a key industrial raw material. Oxygen, when used in smelting processes, can reduce carbon content and remove impurities, shortening smelting times and improving product quality. In healthcare, oxygen can be used to treat hypoxia-related illnesses and has numerous applications in emergency care. Oxygen is also an excellent combustion aid and is widely used in aviation and military applications. Therefore, the development of inexpensive, efficient, and environmentally friendly methods for producing oxygen has become a hot topic in production research.
[0003] Water electrolysis is a process that decomposes water molecules to produce hydrogen and oxygen through the action of electric current. It is safe, has high yields, and is pollution-free. Unfortunately, the slow kinetics of the four-electron transfer reaction in the oxygen evolution reaction usually reduces the overall reaction efficiency, thereby greatly reducing its industrial production efficiency. In addition, the large consumption of electrical energy and the high cost of precious metal catalysts limit the large-scale application of water electrolysis to produce oxygen in industry. So far, the widely used oxygen evolution electrocatalysts with high catalytic activity are still precious metals such as RuO2 and IrO2, but their scarcity and high consumption lead to high manufacturing costs. Therefore, there is an urgent need to develop inexpensive oxygen evolution electrocatalysts with excellent electrocatalytic activity and long-term durability.
[0004] Transition metals, including transition metal phosphides, sulfides, selenides, carbides, and oxides, have attracted great attention due to their abundant content in the Earth's crust, their easy availability, and their excellent catalytic performance in various aspects, and have become the subject of extensive research in the field of electrocatalysis. Through relevant research and development, transition metals and their complexes are expected to become excellent electrocatalysts with great potential. In the oxygen evolution reaction of water electrolysis, transition metals combine with oxygen free radicals to generate MO, which then combines with each other to restore the transition metal M and produce O2, reducing the energy barrier of the reaction and facilitating the rapid oxygen evolution reaction. Although there has been much research on the electrocatalytic oxygen production of transition metal complexes recently, the development of efficient and stable transition metal electrocatalysts remains difficult.
[0005] The study combined transition metal oxides with good electrical conductivity and excellent stability with nickel foam, and through further processing, transition metal hydroxides were also combined with them to obtain a self-supporting transition metal hydroxide / oxide catalyst. The composite material is used in the field of electrocatalytic oxygen evolution, and can safely and efficiently produce oxygen industrially, which has far-reaching significance for future energy and industrial development. Summary of the Invention
[0006] To address the challenges of related technologies, the present invention proposes a composite material composed of transition metal hydroxides / oxides supported on nickel foam for use in water electrolysis to produce oxygen. This composite material overcomes the drawback of powdered catalysts, which tend to fall off the working electrode surface, while also improving catalytic performance and stability, providing a new approach to research in the field of electrocatalysis.
[0007] To this end, the specific technical solutions adopted in the present invention are as follows:
[0008] According to one aspect of the present invention, a method for preparing a self-supporting transition metal hydroxide or oxide composite material is provided, the preparation method comprising the following steps:
[0009] S1. CuCo2O4 / NF was prepared by hydrothermal calcination of copper nitrate trihydrate, cobalt nitrate hexahydrate and urea;
[0010] S2. Using an electrolyte solution containing iron nitrate nonahydrate and nickel nitrate hexahydrate as electrolytes to perform a three-electrode system electrodeposition operation to prepare the self-supporting transition metal hydroxide or oxide composite material.
[0011] Furthermore, the preparation of CuCo2O4 / NF by hydrothermal calcination of copper nitrate trihydrate, cobalt nitrate hexahydrate and urea comprises the following steps:
[0012] Copper nitrate trihydrate, cobalt nitrate hexahydrate, and urea were weighed in a molar ratio of 1:2:10 and placed in a beaker along with distilled water. The mixture was then ultrasonically treated at 150W for 20 minutes. The mixed solution and pretreated nickel foam (10 x 10 x 1 mm) were then placed in a 50 mL polytetrafluoroethylene-lined container and heated to 120°C for 8 hours. The CuCo2O4 / NF precursor was then removed and washed with ethanol and deionized water, then dried in a vacuum drying oven at 60°C for 6 hours. After drying, the precursor was placed in a magnetic boat and heated to 450°C in a tube furnace under nitrogen flow and held at that temperature for 2 hours to obtain the CuCo2O4 / NF sample.
[0013] Furthermore, the three-electrode system electrodeposition operation using an electrolyte solution containing iron nitrate nonahydrate and nickel nitrate hexahydrate as electrolytes to prepare the self-supporting transition metal hydroxide or oxide composite material includes the following steps:
[0014] Ferric nitrate nonahydrate and nickel nitrate hexahydrate were weighed in a 1:1 molar ratio and placed in a beaker. Deionized water was added and ultrasonically treated to prepare a mixed solution of ferric nitrate and nickel nitrate. A three-electrode system was formed using a Pt electrode as a counter electrode, an Ag / AgCl electrode as a reference electrode, and a CuCo2O4 / NF as a working electrode. Electrodeposition was performed using a mixed solution of ferric nitrate and nickel nitrate as an electrolyte (volume 25 mL). The electrodeposition time was 150 s-600 s, the electrodeposition voltage was -1.0 V, and the mixture was vacuum dried (vacuum drying temperature was 60°C, time was 6 h) to obtain NiFe-LDH / CuCo2O4 / NF.
[0015] Furthermore, the nickel foam was pretreated by ultrasonic treatment in 3M hydrochloric acid, deionized water, and ethanol for 15 minutes respectively.
[0016] The electrolyte was prepared by weighing ferric nitrate nonahydrate and nickel nitrate hexahydrate into a beaker, adding deionized water and ultrasonicating for 10 minutes to prepare a 0.05M nickel nitrate and ferric nitrate mixed solution.
[0017] According to another aspect of the present invention, a self-supporting transition metal hydroxide or oxide composite material prepared according to the method for preparing a self-supporting transition metal hydroxide or oxide composite material is provided.
[0018] According to another aspect of the present invention, there is provided a use of a self-supporting transition metal hydroxide or oxide composite material in electrocatalytic oxygen evolution.
[0019] The beneficial effects of the present invention are:
[0020] 1) The present invention synthesizes a self-supporting transition metal hydroxide / oxide composite material by using relatively inexpensive transition metals as raw materials. By comparing different electrodeposition times, it is found that the NiFe-LDH / CuCo2O4 / NF obtained with an electrodeposition time of 300s has the smallest overpotential (180mV) and exhibits excellent electrocatalytic oxygen evolution performance.
[0021] 2) The raw materials used in the present invention are relatively cheap and easily available, the equipment and process conditions used are simple, the operation is easy, the safety is high, the industrial application value is high, and there is great development potential and research value. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] 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. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0023] Figure 1 is a scanning electron microscope image of a self-supporting transition metal hydroxide or oxide composite material NiFe-LDH / CuCo2O4 / NF according to an embodiment of the present invention;
[0024] Figure 2 is a transmission electron micrograph of a self-supporting transition metal hydroxide or oxide composite material NiFe-LDH / CuCo2O4 / NF according to an embodiment of the present invention;
[0025] Figure 3 This is a linear sweep voltammetry curve of a self-supporting transition metal hydroxide or oxide composite material NiFe-LDH / CuCo2O4 / NF (prepared by deposition without electrolysis) according to an embodiment of the present invention;
[0026] Figure 4 3 is a linear sweep voltammetry curve of a self-supporting transition metal hydroxide or oxide composite material NiFe-LDH / CuCo2O4 / NF according to an embodiment of the present invention;
[0027] Figure 5 3 is a Tafel plot of a self-supporting transition metal hydroxide or oxide composite material NiFe-LDH / CuCo2O4 / NF according to an embodiment of the present invention. DETAILED DESCRIPTION
[0028] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention. They are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. By referring to these contents, ordinary technicians in this field should be able to understand other possible implementation methods and the advantages of the present invention.
[0029] Example 1
[0030] Nickel foam (10 x 10 x 1 mm) was ultrasonically treated in 3M hydrochloric acid, deionized water, and ethanol, sequentially for 15 minutes. 0.24 g of copper nitrate trihydrate, 0.58 g of cobalt nitrate hexahydrate, and 0.60 g of urea were weighed and placed in a 50 mL beaker. 35 mL of deionized water was added and ultrasonicated for 15 minutes. The mixed solution was then transferred to a 50 mL polytetrafluoroethylene-lined container and hydrothermally reacted at 120°C for 8 hours. The mixture was then washed several times with deionized water and ethanol and dried under vacuum at 60°C for 6 hours to obtain the CuCo2O4 / NF precursor. The precursor was placed in a tube furnace, heated to 450°C under nitrogen, and then maintained at this temperature for 2 hours to obtain the CuCo2O4 / NF.
[0031] 5.05g of ferric nitrate nonahydrate and 3.64g of nickel nitrate hexahydrate were weighed into a 100mL beaker, and 50mL of deionized water was added. The mixture was ultrasonically treated for 10 minutes, and then a 0.05M mixed solution of ferric nitrate and nickel nitrate was prepared in a 250mL volumetric flask. A three-electrode system was assembled using an Ag / AgCl electrode as the reference electrode, a Pt electrode as the counter electrode, and a CuCo2O4 / NF as the working electrode. The mixed solution served as the electrolyte, and CuCo2O4 / NF was electrodeposited for 150 seconds at a voltage of -1.0V to obtain NiFe-LDH / CuCo2O4 / NF.
[0032] Application Example 1
[0033] Electrocatalytic performance tests were conducted on a standard three-electrode system connected to an electrochemical workstation (CHI660E) at a scan rate of 0.005 V / s. 1.0 M potassium hydroxide solution was used as the electrolyte, an Ag / AgCl electrode was used as the reference electrode, a Pt electrode was used as the counter electrode, and NiFe-LDH / CuCo2O4 / NF was used as the working electrode. The overpotential obtained for the 150 s electrodeposition time was 199 mV, and the corresponding linear sweep voltammetry curve is shown in the figure below. Figure 3 shown.
[0034] Example 2
[0035] Nickel foam (10 x 10 x 1 mm) was ultrasonically treated in 3M hydrochloric acid, deionized water, and ethanol, sequentially for 15 minutes. 0.24 g of copper nitrate trihydrate, 0.58 g of cobalt nitrate hexahydrate, and 0.60 g of urea were weighed and placed in a 50 mL beaker. 35 mL of deionized water was added and ultrasonicated for 15 minutes. The mixed solution was then transferred to a 50 mL polytetrafluoroethylene-lined container and hydrothermally reacted at 120°C for 8 hours. The mixture was then washed several times with deionized water and ethanol and dried under vacuum at 60°C for 6 hours to obtain the CuCo2O4 / NF precursor. The precursor was placed in a tube furnace, heated to 450°C under nitrogen, and then maintained at this temperature for 2 hours to obtain the CuCo2O4 / NF.
[0036] Weigh 5.05g of ferric nitrate nine hydrate and 3.64g of nickel nitrate hexahydrate into a 100mL beaker, add 50mL of deionized water, and ultrasonicate for 10min. Then, use a 250mL volumetric flask to prepare a 0.05M mixed solution of ferric nitrate and nickel nitrate. A three-electrode system was assembled using an Ag / AgCl electrode as a reference electrode, a Pt electrode as a counter electrode, and CuCo2O4 / NF as a working electrode. The mixed solution was used as an electrolyte to electrodeposit CuCo2O4 / NF for 300s at a voltage of -1.0V to obtain NiFe-LDH / CuCo2O4 / NF. The corresponding scanning electron microscopy and transmission electron microscopy images are shown in the figure. Figure 1 and Figure 2 As shown in the scanning electron micrograph, it can be seen that the composite material presents a nano-flower ball morphology formed by the aggregation of nanosheets, and the transmission electron micrograph shows that the composite material and Figure 1 It also presents a nano-flower ball morphology, which also indicates the successful synthesis of NiFe-LDH / CuCo2O4 / NF.
[0037] Application Example 2
[0038] Electrocatalytic performance tests were conducted on a standard three-electrode system connected to an electrochemical workstation (CHI660E) at a scan rate of 0.005 V / s. 1.0 M potassium hydroxide solution was used as the electrolyte, an Ag / AgCl electrode was used as the reference electrode, a Pt electrode was used as the counter electrode, and NiFe-LDH / CuCo2O4 / NF was used as the working electrode. The overpotential obtained for the 300 s electrodeposition time was 180 mV, and the corresponding linear sweep voltammetry curve is shown in the figure below. Figure 3 and Figure 4 As shown, through Figure 4 The Tafel curve calculated by overpotential is shown in the figure below: Figure 5 shown.
[0039] Example 3
[0040] Nickel foam (10 x 10 x 1 mm) was ultrasonically treated in 3M hydrochloric acid, deionized water, and ethanol, sequentially for 15 minutes. 0.24 g of copper nitrate trihydrate, 0.58 g of cobalt nitrate hexahydrate, and 0.60 g of urea were weighed and placed in a 50 mL beaker. 35 mL of deionized water was added and ultrasonicated for 15 minutes. The mixed solution was then transferred to a 50 mL polytetrafluoroethylene-lined container and hydrothermally reacted at 120°C for 8 hours. The mixture was then washed several times with deionized water and ethanol and dried under vacuum at 60°C for 6 hours to obtain the CuCo2O4 / NF precursor. The precursor was placed in a tube furnace, heated to 450°C under nitrogen, and then maintained at this temperature for 2 hours to obtain the CuCo2O4 / NF.
[0041] 5.05 g of ferric nitrate nonahydrate and 3.64 g of nickel nitrate hexahydrate were weighed into a 100 mL beaker, and 50 mL of deionized water was added. The mixture was ultrasonically treated for 10 minutes, and then a 0.05 M mixed solution of ferric nitrate and nickel nitrate was prepared in a 250 mL volumetric flask. A three-electrode system was assembled using an Ag / AgCl electrode as the reference electrode, a Pt electrode as the counter electrode, and a CuCo2O4 / NF as the working electrode. The mixed solution served as the electrolyte, and CuCo2O4 / NF was electrodeposited for 450 seconds at a voltage of -1.0 V to obtain NiFe-LDH / CuCo2O4 / NF.
[0042] Application Example 3
[0043] Electrocatalytic performance tests were conducted on a standard three-electrode system connected to an electrochemical workstation (CHI660E) at a scan rate of 0.005 V / s. Electrochemical tests were conducted using a 1.0 M potassium hydroxide solution as the electrolyte, an Ag / AgCl electrode as the reference electrode, a Pt electrode as the counter electrode, and a NiFe-LDH / CuCo2O4 / NF as the working electrode. The overpotential obtained for the 450 s electrodeposition time was 207 mV, and the corresponding linear sweep voltammetry curve is shown in the figure below. Figure 3 shown.
[0044] Example 4
[0045] Nickel foam (10 x 10 x 1 mm) was ultrasonically treated in 3M hydrochloric acid, deionized water, and ethanol, sequentially for 15 minutes. 0.24 g of copper nitrate trihydrate, 0.58 g of cobalt nitrate hexahydrate, and 0.60 g of urea were weighed and placed in a 50 mL beaker. 35 mL of deionized water was added and ultrasonicated for 15 minutes. The mixed solution was then transferred to a 50 mL polytetrafluoroethylene-lined container and hydrothermally reacted at 120°C for 8 hours. The mixture was then washed several times with deionized water and ethanol and dried under vacuum at 60°C for 6 hours to obtain the CuCo2O4 / NF precursor. The precursor was placed in a tube furnace, heated to 450°C under nitrogen, and then maintained at this temperature for 2 hours to obtain the CuCo2O4 / NF.
[0046] 5.05g of ferric nitrate nonahydrate and 3.64g of nickel nitrate hexahydrate were weighed into a 100mL beaker, and 50mL of deionized water was added. The mixture was ultrasonically treated for 10 minutes, and then a 0.05M mixed solution of ferric nitrate and nickel nitrate was prepared in a 250mL volumetric flask. A three-electrode system was assembled using an Ag / AgCl electrode as the reference electrode, a Pt electrode as the counter electrode, and a CuCo2O4 / NF as the working electrode. The mixed solution served as the electrolyte, and CuCo2O4 / NF was electrodeposited for 600s at a voltage of -1.0V to obtain NiFe-LDH / CuCo2O4 / NF.
[0047] Application Example 4
[0048] Electrocatalytic performance tests were conducted on a standard three-electrode system connected to an electrochemical workstation (CHI660E) at a scan rate of 0.005 V / s. 1.0 M potassium hydroxide solution was used as the electrolyte, an Ag / AgCl electrode was used as the reference electrode, a Pt electrode was used as the counter electrode, and NiFe-LDH / CuCo2O4 / NF was used as the working electrode. The overpotential obtained for the 600 s electrodeposition time was 220 mV, and the corresponding linear sweep voltammetry curve is shown in the figure below. Figure 3 As shown in the figure, it can be seen from the comparison that the NiFe-LDH / CuCo2O4 / NF composited after 300s electrodeposition time has the lowest overpotential and the best catalytic oxygen evolution performance.
[0049] Example 5
[0050] Nickel foam (10 x 10 x 1 mm) was ultrasonically treated in 3M hydrochloric acid, deionized water, and ethanol, sequentially for 15 minutes. 0.24g of copper nitrate trihydrate, 0.58g of cobalt nitrate hexahydrate, and 0.60g of urea were weighed and placed in a 50mL beaker. 35mL of deionized water was added and ultrasonicated for 15 minutes. The mixed solution was transferred to a 50mL polytetrafluoroethylene-lined container and hydrothermally reacted at 120°C for 8 hours. The mixture was then washed several times with deionized water and ethanol and dried under vacuum at 60°C for 6 hours to obtain the CuCo2O4 / NF precursor. The precursor was placed in a tube furnace, heated to 300°C under nitrogen, and then maintained at this temperature for 2 hours to obtain the CuCo2O4 / NF.
[0051] Application Example 5
[0052] Electrocatalytic performance tests were conducted on a standard three-electrode system connected to an electrochemical workstation (CHI660E) at a scan rate of 0.005 V / s. Electrochemical tests were conducted using a 1.0 M potassium hydroxide solution as the electrolyte, an Ag / AgCl electrode as the reference electrode, a Pt electrode as the counter electrode, and a CuCo2O4 / NF as the working electrode. The overpotential obtained for a 300 s electrodeposition time was 250 mV, and the corresponding linear sweep voltammetry curve is shown in the figure below. Figure 4 As shown in the figure, it can be seen from the comparison that the composite NiFe-LDH / CuCo2O4 / NF has the lowest overpotential and the best catalytic oxygen evolution performance, while the Figure 4 The Tafel curve calculated by overpotential is shown in the figure below: Figure 5 As shown in the figure, it can be seen from the comparison that the slope of NiFe-LDH / CuCo2O4 / NF is the smallest, indicating that at the same current density, the overpotential of the catalytic process is lower.
[0053] In summary, the above-mentioned technical solution of the present invention has enabled the synthesis of a self-supporting transition metal hydroxide / oxide composite material using relatively inexpensive transition metals as raw materials. Comparison of different electrodeposition times revealed that the NiFe-LDH / CuCo2O4 / NF obtained with a 300s electrodeposition time exhibited the lowest overpotential (180mV), demonstrating excellent electrocatalytic oxygen evolution performance. Furthermore, the present invention utilizes relatively inexpensive and readily available raw materials, simple equipment and process conditions, easy operation, and high safety. This material has high industrial application value and significant development potential and research value.
[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for preparing a self-supporting transition metal hydroxide or oxide composite material, characterized in that: The preparation method comprises the following steps: S1. CuCo2O4 / NF was prepared by hydrothermal calcination of copper nitrate trihydrate, cobalt nitrate hexahydrate and urea; S2. Performing a three-electrode system electrodeposition operation using an electrolyte solution containing iron nitrate nonahydrate and nickel nitrate hexahydrate as electrolytes to prepare the self-supporting transition metal hydroxide or oxide composite material; The method of preparing CuCo2O4 / NF by using copper nitrate trihydrate, cobalt nitrate hexahydrate and urea using a hydrothermal calcination method includes the following steps: S11, respectively weighing copper nitrate trihydrate, cobalt nitrate hexahydrate and urea, placing them in a beaker, adding deionized water and ultrasonically treating them for 20 minutes to obtain a solution; S12, placing the prepared solution and the pretreated nickel foam in a polytetrafluoroethylene hydrothermal reactor, performing hydrothermal treatment, and vacuum drying to obtain a CuCo2O4 precursor; S13, placing the dried CuCo2O4 precursor in a magnetic boat, placing it in a tube furnace and calcining it under a nitrogen atmosphere to obtain CuCo2O4 / NF; The method of using an electrolyte solution containing iron nitrate nonahydrate and nickel nitrate hexahydrate as electrolytes to perform a three-electrode system electrodeposition operation to prepare the self-supporting transition metal hydroxide or oxide composite material comprises the following steps: S21. Weigh ferric nitrate nonahydrate and nickel nitrate hexahydrate respectively, place them in a beaker, add deionized water, and ultrasonically treat them to prepare a mixed solution of ferric nitrate and nickel nitrate; S22, a three-electrode system was formed by using a Pt electrode as a counter electrode, an Ag / AgCl electrode as a reference electrode, and a CuCo2O4 / NF electrode as a working electrode; S23. Electrodeposition is performed using a mixed solution of ferric nitrate and nickel nitrate as an electrolyte, and NiFe-LDH / CuCo2O4 / NF is prepared after vacuum drying.
2. The method for preparing a self-supporting transition metal hydroxide or oxide composite material according to claim 1, characterized in that: The molar ratio of the copper nitrate trihydrate, the cobalt nitrate hexahydrate and the urea is 1:2:10, the power of the ultrasonic treatment is 150w, and the ultrasonic time is 20min.
3. The method for preparing a self-supporting transition metal hydroxide or oxide composite material according to claim 1, characterized in that: The pretreatment method of the nickel foam is to place it in hydrochloric acid, deionized water, and ethanol for ultrasonic treatment in sequence. The maintenance temperature of the hydrothermal reaction is 120°C and the duration is 8 hours. The size of the nickel foam is 10*10*1mm, and the vacuum drying temperature is 60°C and the time is 6 hours.
4. The method for preparing a self-supporting transition metal hydroxide or oxide composite material according to claim 1, characterized in that: The calcination temperature of the tube furnace is 450°C and the duration is 2h.
5. The method for preparing a self-supporting transition metal hydroxide or oxide composite material according to claim 1, characterized in that: The molar ratio of the ferric nitrate nonahydrate to the nickel nitrate hexahydrate is 1:1, and the concentration of the mixed solution of ferric nitrate and nickel nitrate is 0.05 M; the power of the ultrasonic treatment is 150 W, and the ultrasonic time is 15 min.
6. The method for preparing a self-supporting transition metal hydroxide or oxide composite material according to claim 3, characterized in that: The volume of the electrolyte is 25 mL, the vacuum drying temperature is 60°C, the time is 6 h, the duration of the electrodeposition operation is 150 s-300 s, and the constant voltage is -1.0 V.
7. A self-supporting transition metal hydroxide or oxide composite material prepared by the method for preparing a self-supporting transition metal hydroxide or oxide composite material according to any one of claims 1 to 6.
8. Use of the self-supporting transition metal hydroxide or oxide composite material according to claim 7 in electrocatalytic oxygen evolution.