Preparation method of iron-tungsten co-doped cobaltosic oxide composite material, and obtained composite material and application thereof
By preparing iron-tungsten co-doped cobalt tetroxide composite material, the problem of insufficient oxygen evolution performance of water electrolysis catalyst in alkaline seawater was solved, achieving high-efficiency and low-cost water electrolysis catalytic performance, which is suitable for large-scale production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-22
- Publication Date
- 2026-04-10
AI Technical Summary
Existing water electrolysis catalysts have insufficient oxygen evolution performance and poor stability in alkaline seawater, and their preparation methods are complex and unsuitable for large-scale production.
A cobalt tetroxide composite material co-doped with iron and tungsten was used. After being dissolved by mixing ammonium fluoride, urea, cobalt nitrate, ferric chloride and phosphotungstic acid, the mixture was reacted in a high-pressure reactor to form a nanoflower cluster structure, exposing active sites, synergistically solving the cobalt vacancy problem and improving catalytic performance.
It exhibits excellent HER and OER activity in alkaline water and alkaline seawater, with overpotential lower than that of commercial catalysts. The preparation method is simple and controllable, low in cost, suitable for large-scale production, and has high stability.
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Figure CN121826767A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to composite materials and its preparation and application, and in particular to a preparation method of iron and tungsten co-doped cobalt trioxide composite material, the composite material obtained by the method and the application of the composite material. BACKGROUND
[0002] Hydrogen energy, as an ideal energy carrier, has the advantages of high energy density and zero emission, attracting extensive research attention. Traditional water electrolysis, although mature in technology, relies on precious fresh water, and if scaled up, it will further exacerbate water resource shortage. In contrast, seawater, as an inexhaustible water resource, has become an ideal choice for hydrogen production by electrolysis. Electrolysis of seawater not only effectively utilizes abundant marine resources, but also significantly reduces the cost of hydrogen production, thereby promoting the sustainable development of hydrogen energy. In the process of electrolysis of seawater to produce hydrogen, the selection and performance of the catalyst are still the core variables that determine success or failure.
[0003] Noble metal-based catalysts, such as platinum / platinum-based, ruthenium / ruthenium-based and their alloys, are currently the best choice for catalyzing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, the extremely low abundance of noble metals in the earth's crust and their high price make it difficult for them to be applied on a large scale; therefore, the development of low-cost, high-activity alternative catalysts has become a research focus, and non-noble metal materials are expected to take over the "baton" of platinum group noble metals.
[0004] Among them, the existing electrolytic water electrocatalytic materials mostly focus on hydrogen evolution or reducing energy consumption by replacing anode oxygen evolution reaction, and generally have the problems of single function, insufficient oxygen evolution performance in alkaline seawater and other chlorine-containing environments, and poor long-term stability. At the same time, the preparation methods of existing materials usually have complex process steps and great difficulty in component control, which is not conducive to realizing structure controllable and large-scale preparation. Therefore, it is necessary to develop a bifunctional electrolytic water electrocatalytic material which has a simple preparation method, stable structure, and can simultaneously catalyze hydrogen evolution and oxygen evolution reactions in alkaline water and alkaline seawater systems with high efficiency. SUMMARY
[0005] The purpose of the present application is to overcome the deficiencies in the prior art, and to provide a preparation method of iron and tungsten co-doped cobalt trioxide composite material, which has the advantages of simple process, low cost and suitability for large-scale production. Another purpose of the present application is to provide an iron and tungsten co-doped cobalt trioxide composite material with good electrocatalytic performance. Still another purpose of the present application is to provide the application of the iron and tungsten co-doped cobalt trioxide composite material in electrolytic water catalysts.
[0006] Technical solution: The preparation method of the iron and tungsten co-doped cobalt trioxide composite material comprises the following steps: Step one, ammonium fluoride, urea, cobalt nitrate, ferric chloride, phosphotungstic acid are mixed and dissolved in water, and stirred to obtain a uniform milky white precursor solution; Step two, the milky white precursor solution and the pretreated nickel foam are transferred to an autoclave, heated to 130-150 DEG C, and kept at a constant temperature to obtain a ferrum-tungsten co-doped cobalt-based hydroxide precursor; Step three, the ferrum-tungsten co-doped cobalt-based hydroxide precursor is calcined in a protective atmosphere at 350-400 DEG C, and kept at a constant temperature to obtain a ferrum-tungsten co-doped cobalt trioxide composite material.
[0007] The nanoflower cluster structure formed by the ferrum-tungsten bimetallic cation doping provides a larger specific surface area and exposes a large number of active sites; on the other hand, the introduction of iron cooperatively solves the problem of cobalt vacancy caused by tungsten leaching in the in-situ oxidation process, exposes a higher density of active centers, and cooperatively improves the catalytic performance in the electrolyte containing chloride ions. The protective atmosphere is argon or nitrogen, and the metal salt used is nitrate and chloride salt. Since it is prepared in an aqueous solvent, water-soluble metal salts need to be selected.
[0008] Further, in step one, the mass-volume ratio of ammonium fluoride, urea, cobalt nitrate, ferric chloride, phosphotungstic acid and water is 10mg: 25-40mg: 30mg: 4-6mg: 1-2mg: 5ml.
[0009] Further, in step one, the stirring time is 30-60 minutes.
[0010] Further, in step two, the constant temperature reaction time is 9-12 hours.
[0011] Further, in step two, the pretreatment of the nickel foam is to first immerse it in hydrochloric acid to remove the surface nickel oxide, and then wash it with ethanol and deionized water.
[0012] Further, in step two, the autoclave is a polytetrafluoroethylene autoclave.
[0013] Further, in step three, the protective atmosphere is argon or nitrogen, and the heating rate is 2-5 DEG C / min.
[0014] Further, in step three, the holding time is 2-4 hours.
[0015] The ferrum-tungsten co-doped cobalt trioxide composite material obtained by the above preparation method comprises a nickel foam and a three-dimensional nanoflower cluster-shaped ferrum-tungsten co-doped cobalt trioxide loaded on the nickel foam.
[0016] The ferrum-tungsten co-doped cobalt trioxide composite material described in the application is used as an electrolytic water catalyst.
[0017] Preparation principle: the synergistic effect between iron tungsten ions and tricobalt tetraoxide improves the catalytic performance of the prepared composite material, and can provide more favorable conditions for the catalytic reaction. The main reason for selecting the heterometal-transition metal oxide material is that the introduction of iron can solve the problem of cobalt vacancy caused by the loss of tungsten in the in-situ oxidation process, and provide ideal reaction sites for reconstruction, so that the OER active center with higher density is exposed, thereby reducing the energy barrier of the rate-limiting step and promoting OER. For HER, the iron-tungsten co-doping effectively adjusts the d-orbital center of the overall catalytic material, weakens the adsorption of H*, and thus the obtained tricobalt tetraoxide has higher OER and HER activity. The iron-tungsten co-doped tricobalt tetraoxide composite material has a nanoflower cluster structure, has a larger specific surface area, and is easy to expose rich active sites, and this structure is beneficial to electron transmission.
[0018] Beneficial effects: compared with the prior art, the present application has the following remarkable features: 1. The prepared iron-tungsten co-doped tricobalt tetraoxide composite material has good OER reaction and HER reaction electrocatalytic performance, and exhibits excellent HER and OER activity in alkaline water and alkaline natural seawater environment, and the overpotential is lower than that of commercial RuO2 and Pt / C catalysts; 2. The preparation method is simple and controllable, Fe and W metal ions can be uniformly doped into tricobalt tetraoxide, has a high specific surface area, and the active sites are fully exposed, and the electron transmission and gas diffusion are smooth; 3. The materials used for synthesis are low in price and easy to obtain, which is conducive to reducing production cost and suitable for large-scale production; 4. The iron-tungsten bimetallic ion co-doping effectively inhibits the corrosion of chloride ions, and ensures the structural integrity and catalytic stability of the catalyst in long-term seawater electrolysis. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 is a scanning electron microscope image of the Fe / W-Co3O4 / NF composite material prepared in Example 1; Figure 2 is a transmission electron microscope image of the Fe / W-Co3O4 / NF composite material prepared in Example 1; Figure 3 is an energy spectrum analysis diagram of the Fe / W-Co3O4 / NF composite material prepared in Example 1; Figure 4 is a HER performance curve diagram of the Fe / W-Co3O4 / NF composite material prepared in Example 1 and a commercial Pt / C catalyst in alkaline pure water; Figure 5 is an OER performance curve diagram of the Fe / W-Co3O4 / NF composite material prepared in Example 1 and a commercial RuO2 catalyst in alkaline pure water; Figure 6 This is a graph showing the HER performance of the Fe / W-Co3O4 / NF composite material prepared in Example 1 and a commercial Pt / C catalyst in alkaline seawater. Figure 7 This is an OER performance curve of the Fe / W-Co3O4 / NF composite material prepared in Example 1 and a commercial RuO2 catalyst in alkaline seawater.
[0020] Figure 8 These are scanning electron microscope (SEM) images of Fe / W-Co3O4 / NF composite materials with different proportions. In the image, a is the SEM image of the material obtained in Comparative Example 1, and b is the SEM image of the material obtained in Comparative Example 2. Detailed Implementation
[0021] Unless otherwise specified, all materials and reagents used in the following embodiments are commercially available. Experimental methods not specifically described in the embodiments are generally performed under standard conditions or as recommended by the manufacturer.
[0022] Example 1
[0023] A method for preparing a three-dimensional iron-tungsten co-doped cobalt tetroxide composite material includes the following steps: (1) Take nickel foam, immerse it in 3 mol / L hydrochloric acid and sonicate it for 15 minutes to remove nickel oxide from the surface. Then, clean the nickel foam three times with ethanol and deionized water respectively, and then dry it in a drying oven for 24 hours.
[0024] (2) At room temperature, 100 mg ammonium fluoride, 300 mg urea, 300 mg cobalt nitrate, 60 mg ferric chloride and 20 mg phosphotungstic acid were mixed and dissolved in 50 ml of water and stirred on a stirring table for 40 min to make them fully mixed to form a uniform milky white precursor solution.
[0025] (3) The obtained uniform milky white precursor solution is sonicated for 10 min until it is evenly dispersed. At the same time, the nickel foam in (1) is transferred to a polytetrafluoroethylene high pressure vessel. The obtained milky white precursor solution is heated to 130℃ in a blower box and reacted at a constant temperature for 9 h to obtain the iron-tungsten co-doped cobalt-based hydroxide (Fe / W-CoOOH / NF) precursor.
[0026] (4) The Fe / W-CoOOH / NF precursor obtained in step (3) was washed three times by centrifugation with deionized water to remove excess precipitate on the surface and dried at 60°C for 12 hours.
[0027] (5) The precursor obtained in step (4) is heated to 350°C at a heating rate of 2°C / min under a nitrogen atmosphere, and kept for 2 h. After the reaction is completed, the temperature is cooled to room temperature to obtain a Fe / W-Co3O4 / NF composite material.
[0028] Application Example 1 The Fe / W-Co3O4 / NF composite material obtained in Example 1 is used as a water electrolysis catalyst. Specifically, a three-electrode system is constructed using the material, mercury oxide and a graphite rod, and CV cycle tests, OER and HER performance tests are carried out under alkaline pure water (1M KOH) and alkaline seawater (1M KOH seawater).
[0029] From the scanning electron microscope image of Figure 1 it can be seen that the Fe / W-Co3O4 / NF composite material prepared in Example 1 is in the form of nanoflower clusters. Figure 2 The transmission electron microscope image of Figure 1 confirms the structure described above, and it can also be seen that iron and tungsten are uniformly distributed on the substrate. Figure 3 The transmission energy spectrum of Figure 4 shows that the product of Example 1 is a composite structure of Fe / W-Co3O4 / NF.
[0030] Figure 5 The OER performance curve of Figure 6 shows that the overpotential of the Fe / W-Co3O4 / NF composite material prepared in Example 1 and the commercial RuO2 at a current density of 100 mA / cm 2 is 0.258 V and 0.356 V, respectively. Therefore, the oxygen evolution reaction catalytic performance of the Fe / W-Co3O4 / NF composite material prepared in Example 1 is much higher than that of the commercial RuO2 catalyst, indicating that the Fe / W-Co3O4 / NF composite material prepared has good oxygen evolution reaction catalytic performance. At the same time, under the condition of alkaline seawater, Figure 6 the HER performance curve of 2 shows that the overpotential of the Fe / W-Co3O4 / NF composite material prepared in Example 1 at 10 mA / cm 2 and the commercial Pt / C catalyst is 0.136 V and 0.086 V, respectively, indicating that the Fe / W-Co3O4 / NF composite material prepared still has good hydrogen evolution reaction catalytic performance under the condition of alkaline seawater. Figure 7 The OER performance curve of Figure 6 shows that the overpotential of the Fe / W-Co3O4 / NF composite material prepared in Example 1 at 100 mA / cm2 The overpotential of the prepared Fe / W-Co3O4 / NF composite material is 0.326 V and 0.497 V, which indicates that the prepared Fe / W-Co3O4 / NF composite material still has good catalytic performance for oxygen evolution reaction under the condition of alkaline seawater.
[0031] Example 2
[0032] A preparation method of a three-dimensional structure iron-tungsten co-doped tricobalt tetraoxide composite material, comprising the following steps: (1) Take the nickel foam, immerse it in 3 mol / L hydrochloric acid and perform ultrasonic treatment for 15 minutes to remove the surface nickel oxide. Then, clean the nickel foam with ethanol and deionized water for three times respectively, and then dry in a drying box for 24 h.
[0033] (2) Under room temperature conditions, 200 mg of ammonium fluoride, 600 mg of urea, 600 mg of cobalt nitrate, 80 mg of iron chloride and 40 mg of phosphotungstic acid are mixed and dissolved in 100 ml of water, and stirred on a stirring table for 40 min to fully mix to form a uniform milky white precursor solution.
[0034] (3) The obtained uniform milky white precursor solution is ultrasonically treated for 10 min to be uniformly dispersed, and at the same time, the nickel foam in (1) is transferred to a polytetrafluoroethylene high-pressure kettle, and the obtained milky white precursor solution is heated to 150℃ in a blast oven and kept at a constant temperature for 9 h to obtain an iron-tungsten co-doped cobalt-based hydroxide (Fe / W-CoOOH / NF) precursor.
[0035] (4) The Fe / W-CoOOH / NF precursor obtained in step (3) is centrifuged and washed with deionized water for three times, and the surface excess precipitate is flushed, and then dried at 60℃ for 12 h.
[0036] (5) The precursor obtained in step (4) is heated to 350℃ at a heating rate of 2℃ / min under nitrogen atmosphere, and kept for 2 h. After the reaction is completed, the temperature is cooled to room temperature to obtain the Fe / W-Co3O4 / NF composite material.
[0037] Example 3
[0038] A preparation method of a three-dimensional structure iron-tungsten co-doped tricobalt tetraoxide composite material, comprising the following steps: (1) Take the nickel foam, immerse it in 3 mol / L hydrochloric acid and perform ultrasonic treatment for 15 minutes to remove the surface nickel oxide. Then, clean the nickel foam with ethanol and deionized water for three times respectively, and then dry in a drying box for 24 h.
[0039] (2) Under room temperature, 100 mg of ammonium fluoride, 400 mg of urea, 300 mg of cobalt nitrate, 45 mg of ferric chloride, and 15 mg of phosphotungstic acid were mixed and dissolved in 50 ml of water, and stirred on a stirring table for 40 min to fully mix and form a uniform milky white precursor solution.
[0040] (3) The obtained uniform milky white precursor solution was ultrasonically dispersed for 10 min, and meanwhile, the nickel foam in (1) was transferred to a polytetrafluoroethylene autoclave, and the obtained milky white precursor solution was heated to 130°C in a blast oven and kept at a constant temperature for 9 h to obtain an iron-tungsten co-doped cobalt-based hydroxide (Fe / W-CoOOH / NF) precursor.
[0041] (4) The Fe / W-CoOOH / NF precursor obtained in step (3) was washed by centrifugation with deionized water for three times, and the surface excess precipitate was flushed, and then dried at 60°C for 12 h.
[0042] (5) The precursor obtained in step (4) was heated to 350°C at a heating rate of 2°C / min under a nitrogen atmosphere, and kept for 2 h. After the reaction was completed, the temperature was cooled to room temperature to obtain a Fe / W-Co3O4 / NF composite material.
[0043] Example 4
[0044] A preparation method of a three-dimensional structure iron-tungsten co-doped tricobalt tetraoxide composite material, comprising the following steps: (1) A nickel foam was taken, immersed in 3 mol / L hydrochloric acid, and ultrasonically treated for 15 min to remove the surface nickel oxide. Then, the nickel foam was washed with ethanol and deionized water for three times respectively, and then dried in a drying box for 24 h.
[0045] (2) Under room temperature, 100 mg of ammonium fluoride, 250 mg of urea, 300 mg of cobalt nitrate, 50 mg of ferric chloride, and 15 mg of phosphotungstic acid were mixed and dissolved in 50 ml of water, and stirred on a stirring table for 30 min to fully mix and form a uniform milky white precursor solution.
[0046] (3) The obtained uniform milky white precursor solution was ultrasonically dispersed for 10 min, and meanwhile, the nickel foam in (1) was transferred to a polytetrafluoroethylene autoclave, and the obtained milky white precursor solution was heated to 150°C in a blast oven and kept at a constant temperature for 12 h to obtain an iron-tungsten co-doped cobalt-based hydroxide (Fe / W-CoOOH / NF).
[0047] (4) The Fe / W-CoOOH / NF precursor obtained in step (3) was washed by centrifugation with deionized water for three times, and the surface excess precipitate was flushed, and then dried at 60°C for 12 h.
[0048] (5) The precursor obtained in step (4) is heated to 400°C at a heating rate of 5°C / min under a nitrogen atmosphere, and kept for 5h. After the reaction is completed, the temperature is cooled to room temperature to obtain a Fe / W-Co3O4 / NF composite material.
[0049] Example 5
[0050] A method for preparing a three-dimensional structure of iron and tungsten co-doped tricobalt tetraoxide composite material, comprising the following steps: (1) Take a nickel foam, immerse it in 3 mol / L hydrochloric acid and perform ultrasonic treatment for 15 minutes to remove the surface nickel oxide. Then, clean the nickel foam with ethanol and deionized water three times respectively, and then dry it in a drying box for 24h.
[0051] (2) At room temperature, 100mg of ammonium fluoride, 350mg of urea, 300mg of cobalt nitrate, 60mg of iron chloride and 10mg of phosphotungstic acid are mixed and dissolved in 50ml of water, and stirred on a stirring table for 60min to fully mix and form a uniform milky white precursor solution.
[0052] (3) The obtained uniform milky white precursor solution is ultrasonically treated for 10min to disperse uniformly, and at the same time, the nickel foam in (1) is transferred to a polytetrafluoroethylene autoclave. The obtained milky white precursor solution is heated to 140°C in a blast oven and kept at a constant temperature for 10h to obtain iron and tungsten co-doped cobalt-based hydroxide (Fe / W-CoOOH / NF).
[0053] (4) The Fe / W-CoOOH / NF precursor obtained in step (3) is centrifuged and washed three times with deionized water, and the surface excess precipitate is washed. Dry at 60°C for 12h.
[0054] (5) The precursor obtained in step (4) is heated to 400°C at a heating rate of 4°C / min under a nitrogen atmosphere, and kept for 4h. After the reaction is completed, the temperature is cooled to room temperature to obtain a Fe / W-Co3O4 / NF composite material.
[0055] Application Comparative Example 1 In this comparative example, the remaining preparation and test steps are the same as those in application example 1, and the only difference is that the iron chloride in example 1 is replaced by an equal amount of aluminum chloride. The comparison results show that, since aluminum mainly exists in a stable Al 3+ valence state, it is difficult to participate in reversible electron transfer regulation in the electrochemical process, making it difficult to form effective electron synergistic effect with tungsten, thereby limiting the ability to regulate the lattice oxygen electron structure. In contrast, the synergistic doping of iron and tungsten can achieve more effective electron regulation through the reversible valence change of iron, significantly improving the water electrolysis catalytic performance of the material.
[0056] Application Comparative Example 2 In the present comparative example, the remaining preparation and testing steps are the same as in Application Example 1, with the exception that the phosphotungstic acid in Example 1 is replaced by sodium tungstate. Under the same preparation conditions, although both phosphotungstic acid and sodium tungstate can introduce tungsten elements as tungsten sources, there are significant differences in chemical structure and coordination environment between the two. Phosphotungstic acid belongs to a polyoxometalate structure, which is more conducive to achieving uniform dispersion and stable introduction of tungsten species during the reaction, thereby providing a favorable structural basis for the synergistic effect between iron and tungsten; while sodium tungstate exists in the form of simple tungstate, it is difficult to form a highly ordered synergistic structure under the same conditions, resulting in limited contribution to the improvement of electrocatalytic activity. Therefore, the material obtained by using phosphotungstic acid as the tungsten source performs better in water electrolysis catalytic performance.
[0057] Application Comparative Example 3 In the present comparative example, the remaining preparation and testing steps are the same as in Application Example 1, with the exception that the 60 mg of iron chloride and 20 mg of phosphotungstic acid in Example 1 are respectively adjusted to 30 mg of iron chloride and 5 mg of phosphotungstic acid. The comparison results show that when the amount of iron source is too high, the obtained material is prone to structural stacking, resulting in a decrease in specific surface area, thereby reducing the number of exposed electrocatalytic active sites and being not conducive to the water electrolysis reaction.
[0058] Application Comparative Example 4 In the present comparative example, the remaining preparation and testing steps are the same as in Application Example 1, with the exception that the 60 mg of iron chloride and 20 mg of phosphotungstic acid in Example 1 are respectively adjusted to 40 mg of iron chloride and 30 mg of phosphotungstic acid. The comparison results show that when the amount of tungsten source is too high, it is easy to lead to uneven doping distribution, and thus the morphology of the obtained material presents strong randomness, which is not conducive to the formation of stable synergistic structure between iron and tungsten, thereby affecting the water electrolysis catalytic performance.
[0059] Comparative Example 1 The present comparative example has the same steps as Example 1, with the exception that 60 mg of iron chloride is replaced by 67.6 mg of iron chloride, i.e., the molar ratio of Fe to W is 5:1.
[0060] Comparative Example 2 The present comparative example has the same steps as Example 1, with the exception that 60 mg of iron chloride is replaced by 13.5 mg of iron chloride, i.e., the molar ratio of Fe to W is 1:1.
[0061] As Figure 8 a. When the molar ratio of Fe to W is 5:1, i.e., when the amount of iron source is too high, the material tends to be layered and stacked, the specific surface area decreases sharply, and the electrocatalytic active sites are buried, which is not conducive to the water electrolysis reaction, and Figure 8b indicates that when the ratio is reduced to 1:1, i.e. the amount of tungsten source is too high, the distribution of the doping element is uneven, the morphology is random and disordered, the iron and tungsten cooperative framework is difficult to stabilize, which is not conducive to the formation of a stable cooperative structure between iron and tungsten, thereby weakening the water electrolysis performance.
[0062] In the above examples, the optimal embodiment is Example 1.
Claims
1. A method for preparing an iron-tungsten co-doped cobalt tetroxide composite material, characterized in that, Includes the following steps: Step 1: Mix ammonium fluoride, urea, cobalt nitrate, ferric chloride, and phosphotungstic acid and dissolve them in water, stirring to obtain a uniform milky white precursor solution; Step 2: Transfer the milky white precursor solution and the pretreated nickel foam to a high-pressure reactor, heat to 130~150℃ and react at a constant temperature to obtain the iron-tungsten co-doped cobalt-based hydroxide precursor. Step 3: The iron-tungsten co-doped cobalt-based hydroxide precursor is calcined at 350~400℃ in a protective atmosphere and held at that temperature to obtain the iron-tungsten co-doped cobalt tetroxide composite material.
2. The method for preparing an iron-tungsten co-doped cobalt tetroxide composite material according to claim 1, characterized in that: In step one, the mass-to-volume ratio of ammonium fluoride, urea, cobalt nitrate, ferric chloride, phosphotungstic acid, and water is 10mg:25~40mg:30mg:4~6mg:1~2mg:5ml.
3. The method for preparing an iron-tungsten co-doped cobalt tetroxide composite material according to claim 1, characterized in that: In step one, the stirring time is 30-60 minutes.
4. The method for preparing an iron-tungsten co-doped cobalt tetroxide composite material according to claim 1, characterized in that: In step two, the isothermal reaction time is 9-12 hours.
5. The method for preparing an iron-tungsten co-doped cobalt tetroxide composite material according to claim 1, characterized in that: In step two, the pretreatment of the nickel foam involves first immersing it in hydrochloric acid to remove the nickel oxide on the surface, and then cleaning it with ethanol and deionized water.
6. The method for preparing an iron-tungsten co-doped cobalt tetroxide composite material according to claim 1, characterized in that: In step two, the autoclave is a polytetrafluoroethylene autoclave.
7. The method for preparing an iron-tungsten co-doped cobalt tetroxide composite material according to claim 1, characterized in that: In step three, the protective atmosphere is argon or nitrogen, and the heating rate is 2~5℃ / min.
8. The method for preparing an iron-tungsten co-doped cobalt tetroxide composite material according to claim 1, characterized in that: In step three, the heat preservation time is 2 to 4 hours.
9. A method for preparing cobalt tetroxide co-doped iron-tungsten composite material according to any one of claims 1 to 8, characterized in that: This includes nickel foam, on which three-dimensional nanoflower-like clusters of iron-tungsten co-doped cobalt tetroxide are loaded.
10. The application of the iron-tungsten co-doped cobalt tetroxide composite material according to claim 9 in water electrolysis catalyst.