Heterostructure composite catalyst as well as preparation method and application thereof
By constructing a heterostructure with cobalt/lanthanum co-doped cerium dioxide and nickel-iron layered double hydroxide, the contradiction between activity and stability during CeO2 doping was resolved, realizing a low-cost, high-performance catalyst for oxygen production through water electrolysis, and enhancing the potential for large-scale application of water electrolysis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TAIYUAN UNIVERSITY OF TECHNOLOGY
- Filing Date
- 2026-01-26
- Publication Date
- 2026-04-24
AI Technical Summary
In existing CeO2 doping processes, it is difficult to balance high activity and structural stability. The scarcity and high cost of precious metal catalysts limit the large-scale application of water electrolysis for oxygen production.
A heterostructure was constructed by using a cobalt/lanthanum dual-element doped cerium dioxide support and a nickel-iron layered double hydroxide active layer. A tight interface was formed by electrodeposition, which optimized the electronic structure and support stability. Combined with a foamed copper substrate, it provided high conductivity and mechanical strength.
A low-cost, high-performance alkaline water electrolysis oxygen evolution reaction was achieved. The catalyst has abundant active sites, good charge transport capability and long-term stability, which reduces overpotential and energy barrier and improves reaction kinetics.
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Figure CN121915440A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of water electrolysis for oxygen production, and in particular to a heterogeneous composite catalyst, its preparation method, and its application. Background Technology
[0002] The overuse of chemical fuels has exacerbated global warming and the energy supply crisis. With the continued growth of global energy demand, the development of efficient and stable oxygen evolution reaction (OER) electrocatalysts to achieve large-scale electrocatalytic water splitting for the production of clean and renewable energy has become an urgent need in the field of energy conversion. Electrocatalytic water splitting is a core technology for converting electrical energy into hydrogen energy. The process consists of two half-reactions: the cathode hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER). The OER, as a complex four-electron transfer process, involves multiple electron-proton coupling reactions and is accompanied by high-energy-barrier oxygen-containing intermediates (OH, O, ...). The formation and transformation of OOH (O2O3) leads to high reaction overpotentials and slow kinetics. Therefore, designing OER electrocatalysts with low overpotentials, small Tafel slopes, and long-term stability in alkaline media is a key scientific and technological issue for promoting the large-scale application of water electrolysis technology.
[0003] Currently, while noble metal-based catalysts (such as Ir, Ru, and their oxides IrO2 and RuO2) exhibit excellent OER catalytic activity, their scarcity and high cost limit their large-scale industrial application. In recent years, non-noble metal-based catalysts such as oxides and hydroxides of transition metals like nickel, cobalt, and iron have become a research hotspot for OER catalysts due to their abundant resources, lower cost, and tunable catalytic performance. Meanwhile, cerium dioxide (CeO2), with its strong oxygen storage capacity and excellent electron transfer characteristics, is often used as a co-catalyst to construct heterostructures with transition metal compounds to improve catalytic performance. However, CeO2 itself suffers from low conductivity and large particle size. While doping can improve its performance by modifying its electronic structure, it easily induces lattice distortion, making it difficult to balance activity and structural stability.
[0004] Currently, no systematic solution has been found to address the contradiction between "doping-modulated activity" and "maintaining structural stability" during CeO2 doping. Therefore, exploring a composite catalyst that can balance high activity, good conductivity, and long-term stability is urgently needed. Summary of the Invention
[0005] The purpose of this invention is to provide a heterostructured composite catalyst, its preparation method, and its application. By optimizing the electronic structure and stability of the support through cobalt / lanthanum dual-element doping, and by utilizing electrodeposition to construct a tight heterostructure interface to promote charge transport, the catalyst achieves a synergistic improvement in high activity and long-term stability, providing a low-cost, high-performance solution for alkaline water electrolysis.
[0006] To achieve the above objectives, the present invention provides a heterostructured composite catalyst, comprising a copper foam substrate, a cobalt and lanthanum co-doped cerium dioxide support supported on the copper foam substrate, and a nickel-iron layered double hydroxide active layer electrodeposited on the surface of the support.
[0007] This invention also provides a method for preparing a heterostructured composite catalyst, comprising the following steps: S1. Mix cerium source, cobalt source, lanthanum source, structure directing agent, and ethylene glycol to obtain a precursor solution; S2. Pre-treat the copper foam to obtain a copper foam substrate. Perform a hydrothermal reaction between the copper foam substrate and the precursor solution. After the hydrothermal reaction is completed, wash and dry the substrate and calcine it in an air atmosphere to obtain a copper foam substrate loaded with cobalt / lanthanum co-doped cerium dioxide, denoted as Co,La-CeO2 / CF. S3. Using a copper foam substrate loaded with cobalt / lanthanum co-doped cerium dioxide as the working electrode, a graphite rod as the counter electrode, and an Ag / AgCl electrode in saturated potassium chloride solution as the reference electrode, constant potential electrodeposition was performed in the electrolyte to obtain a heterostructured composite catalyst, denoted as NiFe-LDH / Co,La-CeO2 / CF.
[0008] Preferably, in S1, the cerium source includes cerium nitrate hexahydrate, the cobalt source includes cobalt acetate tetrahydrate, and the lanthanum source includes lanthanum nitrate hexahydrate; the molar ratio of the metal cations in the cerium source, cobalt source, and lanthanum source is 1~2:0.25~0.75:0.25~0.75.
[0009] Preferably, in S1, the structure-directing agent includes hexamethylenetetramine, and the mass-volume molar ratio of the structure-directing agent, ethylene glycol, and cerium source to the metal cation is 0.1~0.15g:15~20mL:1~2mmol.
[0010] Preferably, in S2, the pretreatment process for the foamed copper is as follows: ultrasonic cleaning with hydrochloric acid, ethanol and water in sequence, followed by drying at 50~70℃ for 2~3 hours.
[0011] Preferably, in S2, the hydrothermal reaction temperature is 160~200℃ and the hydrothermal reaction time is 6~12h.
[0012] Preferably, in S2, the calcination heating rate is 1~3℃ / min, the calcination temperature is 300~500℃, and the calcination time is 1~4h.
[0013] Preferably, in S3, the electrolyte is an aqueous solution of a nickel source and an iron source. The nickel source includes nickel chloride hexahydrate, and the iron source includes ferric chloride hexahydrate. The molar volume ratio of nickel ions, iron ions, and water in the electrolyte is 3~6 mmol:1.5 mmol:150 mL.
[0014] Preferably, in S3, the potential for constant potential electrodeposition is -1.6 to -1.2V, and the time for constant potential electrodeposition is 300 to 1000s.
[0015] The present invention also provides an application of a heterostructured composite catalyst, wherein the above-mentioned heterostructured composite catalyst is applied to the alkaline water electrolysis oxygen evolution reaction.
[0016] Therefore, the present invention, employing the above-mentioned heterostructure composite catalyst, its preparation method, and its application, has the following beneficial effects: (1) The heterostructure composite catalyst of the present invention has a three-dimensional nanoflower-like morphology and rich mesoporous structure, which greatly increases the electrochemical active surface area, provides a large number of active sites for the reaction, and is conducive to electrolyte penetration and rapid desorption of oxygen bubbles.
[0017] (2) The heterostructure composite catalyst of the present invention co-dops CeO2 with Co and La, and uses Co to induce the generation of high-density oxygen vacancies to optimize the electronic structure and promote water dissociation; at the same time, the strong La-O bond formed by La doping stabilizes the lattice, which enhances the intrinsic activity and strengthens the stability of the support structure, thus overcoming the problem of lattice instability that may be caused by single doping.
[0018] (3) The heterostructure composite catalyst of the present invention forms a tight heterostructure between the nickel-iron layered double hydroxide (NiFe-LDH) active layer and the cobalt and lanthanum co-doped cerium dioxide (Co,La-CeO2) support, which effectively regulates the charge distribution at the interface, reduces the charge transfer resistance, optimizes the adsorption energy of the reaction intermediate, and thus synergistically reduces the overpotential and energy barrier of the oxygen evolution reaction and improves the kinetics of the oxygen evolution reaction.
[0019] (4) The heterostructure composite catalyst of the present invention uses copper foam as a conductive substrate, which has a three-dimensional interconnected structure with high porosity (>90%). This not only provides a huge specific surface area for uniform catalyst loading and enhances the exposure of active sites, but also facilitates electrolyte wetting and rapid desorption of oxygen bubbles during the reaction process. At the same time, the excellent intrinsic conductivity and mechanical strength of copper foam itself ensure that the catalyst has an efficient electron transport path and good structural durability during operation.
[0020] (5) The present invention adopts a conventional hydrothermal synthesis combined with constant potential electrodeposition as a preparation route. The process is simple, the conditions are mild and controllable, and no complex equipment or harsh post-processing is required. It effectively reduces the preparation cost and operation complexity and has good potential for large-scale production.
[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0022] Figure 1 These are SEM images of the heterostructured composite catalysts prepared in Example 1 and Comparative Example 1 of this invention. Figure 2 This is a TEM image of the heterostructured composite catalyst prepared in Example 1 of this invention; Figure 3 This is an energy dispersive X-ray spectral surface scan elemental distribution diagram of the heterostructure composite catalyst prepared in Example 1 of this invention; Figure 4 These are the X-ray diffraction patterns of the heterostructure composite catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention; Figure 5 The X-ray photoelectron energy total spectrum and elemental spectra of the heterostructure composite catalyst prepared in Example 1 of this invention are shown. Figure 6 This is a graph showing the electrochemical performance of the heterostructure composite catalysts prepared in Example 1 and Comparative Examples 1-4 of this invention under alkaline conditions for the oxygen evolution reaction. Figure 7 The heterostructured composite catalyst prepared in Example 1 of this invention is used at 100 mA·cm⁻¹ -2 The stability test curve of the chronopotential method is shown below. Detailed Implementation
[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.
[0024] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0025] In this invention, unless otherwise specified, the test materials and instruments are all conventional test materials in the field and can be purchased through commercial channels.
[0026] Example 1 A heterostructured composite catalyst includes a copper foam substrate, a cobalt and lanthanum co-doped cerium dioxide support supported on the copper foam substrate, and a nickel-iron layered double hydroxide active layer electrodeposited on the surface of the support.
[0027] The preparation method of the above-mentioned heterostructure composite catalyst includes the following steps: S1. Add 1.5 mmol of cerium nitrate hexahydrate (Ce(NO3)3·6H2O), 0.5 mmol of cobalt acetate tetrahydrate ((CH3COO)2Co·4H2O), 0.5 mmol of lanthanum nitrate hexahydrate (La(NO3)3·6H2O), and 0.125 g of hexamethylenetetramine (HMTA) sequentially to a beaker containing 15 mL of ethylene glycol, and stir magnetically until a homogeneous and transparent precursor solution is formed; S2. A 2cm × 3cm copper foam was sequentially ultrasonically cleaned for 5 minutes each in 10% hydrochloric acid, anhydrous ethanol, and deionized water to remove surface oxides and impurities. It was then dried in a vacuum oven at 60℃ for 2 hours. The precursor solution was transferred to a PTFE-lined stainless steel high-pressure reactor, and the pretreated copper foam was vertically immersed in the precursor solution, ensuring complete submersion. The reactor was placed in an oven and subjected to a hydrothermal reaction at 170℃ for 8 hours. After the hydrothermal reaction, the mixture was allowed to cool naturally to room temperature. The copper foam loaded with the precursor was removed, washed repeatedly with anhydrous ethanol, and then dried in air. The dried sample was placed in a muffle furnace and heated to 400℃ at a heating rate of 2℃ / min under air atmosphere. It was then calcined at this temperature for 2 hours and subsequently cooled naturally to room temperature to obtain a copper foam substrate loaded with cobalt / lanthanum co-doped cerium dioxide, denoted as Co,La-CeO2 / CF. S3. Dissolve 4.5 mmol of nickel chloride hexahydrate and 1.5 mmol of ferric chloride hexahydrate in 150 mL of deionized water to obtain an electrolyte. Use a copper foam substrate loaded with cobalt / lanthanum co-doped cerium dioxide as the working electrode, a graphite rod as the counter electrode, and an Ag / AgCl electrode with saturated potassium chloride solution as the reference electrode. Perform constant potential electrodeposition in the electrolyte for 600 s, where the potential for constant potential electrodeposition relative to the Ag / AgCl electrode is -1.4 V. After electrodeposition, remove the working electrode, rinse it with deionized water to remove residual electrolyte on the surface, and then dry it at room temperature to obtain a heterostructured composite catalyst, denoted as NiFe-LDH / Co,La-CeO2 / CF.
[0028] Example 2 A heterostructured composite catalyst includes a copper foam substrate, a cobalt and lanthanum co-doped cerium dioxide support supported on the copper foam substrate, and a nickel-iron layered double hydroxide active layer electrodeposited on the surface of the support.
[0029] The preparation method of the above heterostructure composite catalyst is the same as that in Example 1, except that the amount of hexamethylenetetramine (HMTA) added in S1 is 0.15g.
[0030] Example 3 A heterostructured composite catalyst includes a copper foam substrate, a cobalt and lanthanum co-doped cerium dioxide support supported on the copper foam substrate, and a nickel-iron layered double hydroxide active layer electrodeposited on the surface of the support.
[0031] The preparation method of the above heterostructure composite catalyst is the same as that in Example 1, except that the amount of ethylene glycol used in S1 is 20 mL.
[0032] Example 4 A heterostructured composite catalyst includes a copper foam substrate, a cobalt and lanthanum co-doped cerium dioxide support supported on the copper foam substrate, and a nickel-iron layered double hydroxide active layer electrodeposited on the surface of the support.
[0033] The preparation method of the above heterostructure composite catalyst is the same as that in Example 1, except that the hydrothermal reaction temperature in S2 is 180℃.
[0034] Comparative Example 1 A heterostructured composite catalyst includes a copper foam substrate and a cobalt and lanthanum co-doped cerium dioxide support loaded on the copper foam substrate.
[0035] The preparation method of the above heterostructure composite catalyst is the same as that in Example 1, except that only S1 and S2 are performed, and S3 is not performed. The resulting heterostructure composite catalyst is denoted as Co,La-CeO2 / CF.
[0036] Comparative Example 2 A heterostructured composite catalyst includes a copper foam substrate and a cerium dioxide support loaded on the copper foam substrate.
[0037] The preparation method of the above heterostructure composite catalyst is the same as that in Example 1, except that cobalt acetate tetrahydrate and lanthanum nitrate hexahydrate are not added in S1, and S3 is not performed. The resulting heterostructure composite catalyst is denoted as CeO2 / CF.
[0038] Comparative Example 3 A heterostructured composite catalyst includes a foamed copper substrate and a nickel-iron layered double hydroxide active layer electrodeposited on the substrate surface.
[0039] The preparation method of the above heterostructure composite catalyst is the same as that in Example 1, except that S1 is not performed, only the pretreatment of copper foam is performed in S2, and the pretreated copper foam substrate is used as the working electrode in S3. The resulting heterostructure composite catalyst is denoted as NiFe-LDH / CF.
[0040] Comparative Example 4 Commercial ruthenium dioxide RuO2 catalyst.
[0041] The morphology and structure of the heterostructured composite catalysts prepared in Example 1 and Comparative Example 1 were characterized using scanning electron microscopy (SEM), and the results are as follows: Figure 1 As shown, where Figure 1 Image (a) in the image is a SEM image of the heterostructured composite catalyst of Comparative Example 1 on a 10 μm scale. Figure 1 Image (b) in the image is a SEM image of the heterostructured composite catalyst of Comparative Example 1 on a 5 μm scale. Figure 1(c) in the figure is a SEM image of the heterostructured composite catalyst of Comparative Example 1 on a 1 μm scale. Figure 1 Image (d) in the image is a SEM image of the heterostructured composite catalyst of Example 1 on a 10 μm scale. Figure 1 Image (e) in the image is a SEM image of the heterostructured composite catalyst of Example 1 on a 5 μm scale. Figure 1 Image (f) in the image is a SEM image of the heterostructured composite catalyst from Example 1 on a 1 μm scale. Figure 1 As can be seen, the Co,La-CeO2 / CF in Comparative Example 1 exhibits a regular spherical nanoflower-like structure, while the NiFe-LDH / Co,La-CeO2 / CF in Example 1 successfully loaded sheet-like NiFe-LDH on the surface of the nanoflower, forming a more loose and porous composite structure and increasing the specific surface area.
[0042] The morphology and structure of the heterostructured composite catalyst prepared in Example 1 were characterized by transmission electron microscopy (TEM), and the results are as follows: Figure 2 As shown, where Figure 2 Image (a) is a TEM image of the heterostructure composite catalyst of Example 1 at a scale of 200 nm. Figure 2 Image (b) is a TEM image of the heterostructure composite catalyst of Example 1 at a 100 nm scale. Figure 2 Image (c) in the image is a TEM image of the heterostructured composite catalyst from Example 1 at a 10 nm scale. Figure 2 As can be seen from the data, CeO2 and NiFe-LDH coexist in NiFe-LDH / Co,La-CeO2 / CF in Example 1.
[0043] The spatial distribution of elements in the heterostructured composite catalyst prepared in Example 1 was characterized using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and the results are as follows: Figure 3 As shown, where Figure 3 (a) in the figure is the EDS distribution diagram of Fe element. Figure 3 (b) in the figure is the EDS distribution diagram of Ni element. Figure 3 (c) in the figure is the EDS distribution map of Co element. Figure 3 (d) in the figure is the EDS distribution diagram of element O. Figure 3 (e) in the figure is the EDS distribution diagram of Ce element. Figure 3 (f) in the figure is the EDS distribution plot of La elements. From Figure 3 As can be seen from the data, the Ni, Fe, Co, La, Ce and O elements are uniformly distributed in the NiFe-LDH / Co,La-CeO2 / CF of Example 1.
[0044] The heterostructured composite catalysts prepared in Example 1 and Comparative Examples 1-2 were characterized by X-ray diffraction, and the results are as follows: Figure 4 As shown. From Figure 4 As can be seen from the data, the heterostructure composite catalyst of Example 1 exhibits characteristic diffraction peaks of NiFe-LDH while also displaying characteristic diffraction peaks of CeO2, indicating that NiFe-LDH / Co,La-CeO2 / CF was successfully composited.
[0045] The elemental composition and chemical valence states of the heterostructured composite catalyst prepared in Example 1 were characterized by X-ray photoelectron spectroscopy (XPS), and the results are as follows: Figure 5 As shown. Among them. Figure 5 (a) in the image represents the total X-ray photoelectron energy spectrum of the heterostructure composite catalyst. Figure 5 (b) in the image is the X-ray photoelectron spectrum of Ce. Figure 5 (c) in the image is the X-ray photoelectron spectrum of Co. Figure 5 (d) in the image is the X-ray photoelectron spectrum of Fe. Figure 5 (e) in the image is the X-ray photoelectron spectrum of La. Figure 5 In the diagram, (f) is the X-ray photoelectron spectrum of Ni. Figure 5 (g) in the image represents the X-ray photoelectron spectrum of element O. From... Figure 5 As can be seen from the data, the heterostructure composite catalyst of Example 1 contains Ce, Co, La, Ni, Fe and O elements. In particular, the high binding energy component accounts for a large proportion in the O1s spectrum, indicating that there are abundant oxygen vacancies or adsorbed oxygen species on the catalyst surface.
[0046] Electrochemical performance tests were conducted on the catalysts prepared in Examples 1 and Comparative Examples 1-4 at room temperature (25°C) using a standard three-electrode system. The catalysts prepared in Examples 1 and Comparative Examples 1-4 were used as the working electrode, a graphite rod as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrolyte was a 1.0 MkOH solution with continuous argon or nitrogen gas to remove dissolved oxygen. Cyclic voltammetry was performed on the working electrode within the non-oxygen evolution reaction potential range until the cyclic voltammetric curve stabilized. Subsequently, LSV tests were performed at a low scan rate (5 mV / s) within a specific potential window (1.0 V to 1.8 V vs. RHE) to obtain polarization curves. All potentials were converted to potentials relative to the reversible hydrogen electrode (RHE) according to the Nernst equation for the reference electrode.
[0047] 5 mg of commercial RuO2 powder (Comparative Example 4) was dispersed in 1 mL of a mixed solution of isopropanol and ethanol (volume ratio 2:1), and 60 μL of 5 wt% Nafion solution was added. The mixture was ultrasonically stirred to form a homogeneous slurry. 70 μL of this slurry was drop-coated onto a pretreated copper foam surface and dried at room temperature to serve as the working electrode for Comparative Example 4. The results are as follows: Figure 6 As shown, where Figure 6 (a) in the figure is the linear sweep voltammetry curve. Figure 6 (b) in the figure is the Tafel slope plot. From Figure 6 As can be seen from the data, the NiFe-LDH / Co,La-CeO2 / CF in Example 1 exhibits performance at 10 mA·cm⁻¹. -2 The overpotential at current density is 172mV, 50mA·cm -2 At a current density of 230 mV, the Tafel slope is 74.65 mV·dec. -1 Comparative Example 1: Co,La-CeO2 / CF at 50 mA·cm -2 The overpotential at the current density is 484 mV, and the Tafel slope is 97.99 mV·dec. -1 Comparative Example 2: CeO2 / CF at 50 mA·cm -2 The overpotential at the current density is 496 mV, and the Tafel slope is 158.7 mV·dec. -1 Comparative Example 3 NiFe-LDH / CF at 50 mA·cm -2 The overpotential at the current density is 320 mV, and the Tafel slope is 87.12 mV·dec. -1 Comparative Example 4: RuO2 catalyst at 50 mA·cm⁻¹ -2 The overpotential at the current density is 438 mV, and the Tafel slope is 110.2 mV·dec. -1 This indicates that the NiFe-LDH / Co,La-CeO2 / CF of Example 1 has the lowest overpotential and the smallest Tafel slope, suggesting that its reaction kinetics are the fastest.
[0048] At 100mA·cm -2 The stability of the heterostructured composite catalyst prepared in Example 1 was tested using a chronopotentiometric method. A three-electrode testing system was constructed using a copper foam substrate supported on cobalt / lanthanum co-doped cerium dioxide as the working electrode, a graphite rod as the counter electrode, and an Ag / AgCl electrode as the reference electrode. The electrolyte was a 1.0 M KOH aqueous solution, and the reaction was carried out at 100 mA·cm⁻¹. -2 Under a constant current density, the working electrode was subjected to a long-term electrochemical stability test for 50 hours using the chronopotential method. The results are as follows: Figure 7 As shown. From Figure 7It can be seen from this that at 100mA·cm -2 After 50 hours of continuous operation at current density, the performance degradation is extremely low (approximately 2.86%), demonstrating excellent stability.
[0049] Therefore, this invention employs the aforementioned heterostructure composite catalyst, its preparation method, and its application. By combining a Co / La dual-element co-doped CeO2 support with a NiFe-LDH active layer, a heterostructure with tight interfacial coupling is constructed. This achieves synergistic optimization of support stability, electronic conductivity, active site density, and interfacial charge transport capability, thereby obtaining performance significantly superior to single-component or commercial catalysts, providing a low-cost, high-performance solution for alkaline water electrolysis.
[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A heterogeneous composite catalyst, characterized in that: It includes a copper foam substrate, a cobalt and lanthanum co-doped cerium dioxide support loaded on the copper foam substrate, and a nickel-iron layered double hydroxide active layer electrodeposited on the surface of the support.
2. The method for preparing a heterostructured composite catalyst according to claim 1, characterized in that: Includes the following steps: S1. Mix cerium source, cobalt source, lanthanum source, structure directing agent, and ethylene glycol to obtain a precursor solution; S2. Pre-treat the copper foam to obtain a copper foam substrate. Perform a hydrothermal reaction between the copper foam substrate and the precursor solution. After the hydrothermal reaction is completed, wash and dry the substrate and calcine it in an air atmosphere to obtain a copper foam substrate loaded with cobalt / lanthanum co-doped cerium dioxide, denoted as Co,La-CeO2 / CF. S3. Using a copper foam substrate loaded with cobalt / lanthanum co-doped cerium dioxide as the working electrode, a graphite rod as the counter electrode, and an Ag / AgCl electrode in saturated potassium chloride solution as the reference electrode, constant potential electrodeposition was performed in the electrolyte to obtain a heterostructured composite catalyst, denoted as NiFe-LDH / Co,La-CeO2 / CF.
3. The method for preparing a heterostructured composite catalyst according to claim 2, characterized in that: In S1, the cerium source includes cerium nitrate hexahydrate, the cobalt source includes cobalt acetate tetrahydrate, and the lanthanum source includes lanthanum nitrate hexahydrate; the molar ratio of the metal cations in the cerium, cobalt, and lanthanum sources is 1~2:0.25~0.75:0.25~0.
75.
4. The method for preparing a heterostructured composite catalyst according to claim 2, characterized in that: In S1, the structure-directing agent includes hexamethylenetetramine, and the mass-volume molar ratio of the structure-directing agent, ethylene glycol, and cerium source metal cations is 0.1~0.15g:15~20mL:1~2mmol.
5. The method for preparing a heterostructured composite catalyst according to claim 2, characterized in that: In S2, the pretreatment process for copper foam is as follows: ultrasonic cleaning with hydrochloric acid, ethanol and water in sequence, followed by drying at 50~70℃ for 2~3 hours.
6. The method for preparing a heterostructured composite catalyst according to claim 2, characterized in that: In S2, the hydrothermal reaction temperature is 160~200℃, and the hydrothermal reaction time is 6~12h.
7. The method for preparing a heterostructured composite catalyst according to claim 2, characterized in that: In S2, the heating rate during calcination is 1~3℃ / min, the calcination temperature is 300~500℃, and the calcination time is 1~4h.
8. The method for preparing a heterostructured composite catalyst according to claim 2, characterized in that: In S3, the electrolyte is an aqueous solution of nickel and iron sources. The nickel source includes nickel chloride hexahydrate, and the iron source includes ferric chloride hexahydrate. The molar volume ratio of nickel ions, iron ions and water in the electrolyte is 3~6 mmol:1.5 mmol:150 mL.
9. The method for preparing a heterostructured composite catalyst according to claim 2, characterized in that: In S3, the potential for constant potential electrodeposition is -1.6 to -1.2V, and the time for constant potential electrodeposition is 300 to 1000s.
10. The application of a heterostructured composite catalyst, characterized in that: The heterostructured composite catalyst prepared by the method of preparation of the heterostructured composite catalyst according to claim 1 or any one of claims 2-9 is applied to the oxygen evolution reaction of alkaline water electrolysis.