NilaCo3O4 / / cc catalyst, preparation method and application thereof

Abstract

This invention discloses a NiLaCo3O4 / / CC catalyst, its preparation method, and its applications. The NiLaCo3O4 / / CC catalyst contains Ni, La, Co, and O elements, which are uniformly distributed on the surface of carbon cloth, forming a nanosheet structure. The raw materials used in the preparation of this catalyst include cobalt salt, nickel salt, and lanthanum salt, wherein the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt, and lanthanum in the lanthanum salt is 40:15–25:5.2–7.8. The catalyst of this invention can be used for acidic oxygen evolution reaction (OER), exhibiting a low OER overpotential and good electrocatalytic activity.

Description

Technical Field

[0001] This invention relates to a NiLaCo3O4 / / CC catalyst, its preparation method, and its application. Background Technology

[0002] In recent years, researchers have conducted extensive research on reducing the amount of precious metals used, enhancing the intrinsic activity of non-precious metals, and extending the service life of catalysts to meet the application requirements of acidic oxygen evolution reaction (OER) catalysts. Among these efforts, strategies such as constructing Co3O4-based heterostructures, elemental doping, and defect and oxygen vacancy manipulation have been employed to regulate the electronic structure and reaction pathway of the catalyst, accelerating the OER reaction kinetics. However, compared to precious metal-based catalysts, further reduction of the oxygen evolution overpotential of Co3O4-based catalysts in acidic OER reactions is needed to improve their activity in this process.

[0003] CN120575233 A discloses a W-doped Co3O4-supported Ru single-atom catalyst for acidic OER and its preparation method. The preparation method includes the following steps: First, 2-methylimidazolium is dissolved in ultrapure water, and Co(NO3)2•6H2O is dissolved in ultrapure water in another beaker. The Co(NO3)2•6H2O solution is poured into the 2-methylimidazolium solution and stirred until completely dissolved. Carbon cloth is impregnated with this solution, and the washed carbon cloth is collected and dried. Then, Na2WO4•2H2O is dissolved in ultrapure water and ethanol solution, and the above-mentioned carbon cloth is placed in the solution for hydrothermal reaction. The washed carbon cloth is collected and dried. The above-mentioned carbon cloth is placed in an aqueous solution of RuCl3 for ion exchange, and finally calcined in air. The catalyst RuCoWO4 obtained by this preparation method is... x / CC at 10mA•cm -2 The oxygen evolution overpotential at the current density is 198 mV.

[0004] CN121250445A discloses a RuO2-Co3O4 electrocatalytic material, its preparation method, and its application. The preparation method includes the following steps: using activated carbon cloth as the working electrode, constant potential electrodeposition is performed in a cobalt salt-containing electrolyte, followed by cleaning and drying to obtain Co(OH)2-loaded carbon cloth; then, the carbon cloth undergoes a first heat treatment to obtain Co3O4-loaded carbon cloth; next, the carbon cloth is immersed in a ruthenium salt-containing solution to allow the ruthenium salt to adsorb onto the Co3O4, followed by cleaning and drying to obtain a precursor; the precursor undergoes a second heat treatment to obtain the RuO2-Co3O4 heterojunction electrocatalytic material. This catalytic material exhibits high performance at 10 mA•cm⁻¹. -2 The oxygen evolution overpotential at the current density is 226 mV.

[0005] CN120443239A discloses a La-Ca dual-doped Co3O4 electrocatalyst, its preparation method, and its application. The preparation method uses a Pt-coated titanium mesh (PTL) as the substrate and working electrode. A Co-LaCa thin film is deposited on the surface of the PTL using a self-made target via magnetron sputtering. The obtained PTL sheet is then washed, dried, and calcined to obtain the catalyst. The resulting catalyst exhibits high performance at 10 mA•cm⁻¹. -2 The oxygen evolution overpotential at current density is above 260mV. Summary of the Invention

[0006] In view of this, one object of the present invention is to provide a NiLaCo3O4 / / CC catalyst that can be used in acidic OER reactions, which operates at 10 mA·cm⁻¹. -2 The oxygen evolution overpotential at the current density is low (≤177mV), and the electrocatalytic activity is high. Another object of this invention is to provide a method for preparing the above-mentioned NiLaCo3O4 / / CC catalyst, which has a stable process. A further object of this invention is to provide the application of the above-mentioned NiLaCo3O4 / / CC catalyst in the acidic oxygen evolution reaction.

[0007] The present invention achieves the above objectives using the following technical solutions.

[0008] On the one hand, the present invention provides a NiLaCo3O4 / / CC catalyst, which contains Ni, La, Co and O elements, which are uniformly distributed on the surface of carbon cloth and form a nanosheet structure on the surface of carbon cloth; The raw materials used in the preparation of this catalyst include cobalt salt, nickel salt and lanthanum salt, wherein the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt and lanthanum in the lanthanum salt is 40:15-25:5.2-7.8.

[0009] The NiLaCo3O4 / / CC catalyst according to the present invention is preferably obtained by first depositing a mixed solution containing cobalt salt, nickel salt and lanthanum salt on the surface of carbon cloth by electrochemical deposition, and then calcining it; In the X-ray diffraction pattern of the catalyst, characteristic diffraction peaks appear at 2θ of 36.56°±0.2°, 44.62°±0.2°, 59.22°±0.2° and 65.04°±0.2°, respectively. Among these characteristic diffraction peaks, the characteristic diffraction peak at 2θ of 36.56°±0.2° is the strongest. The diffraction peak at 2θ, which is 36.56°±0.2°, belongs to the (311) crystal plane, whose lattice spacing is greater than or equal to 0.295 nm. In this catalyst, Co 3+ / Co 2+The ratio is less than or equal to 0.6, and the ratio of oxygen vacancies to lattice oxygen is greater than or equal to 1.5.

[0010] On the other hand, the present invention also provides a method for preparing the NiLaCo3O4 / / CC catalyst as described above, comprising the following steps: 1) A mixed solution containing cobalt salt, nickel salt and lanthanum salt is formed; wherein the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt and lanthanum in the lanthanum salt is 40:15~25:5.2~7.8; 2) Using the mixed solution containing cobalt salt, nickel salt and lanthanum salt obtained in step 1) as the electrodeposition solution, and carbon cloth as the working electrode, a precursor is deposited on the surface of the working electrode by electrochemical deposition; then the working electrode with the precursor deposited on the surface is removed. 3) The working electrode with the precursor deposited on its surface obtained in step 2) is calcined to obtain the NiLaCo3O4 / / CC catalyst.

[0011] According to the preparation method of the present invention, preferably, in step 1), the cobalt salt is cobalt nitrate, the nickel salt is nickel nitrate, and the lanthanum salt is lanthanum nitrate; the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt, and lanthanum in the lanthanum salt is 40:18~22:6~7.5.

[0012] According to the preparation method of the present invention, preferably, step 1) includes the following specific steps: (a) Formation of an aqueous solution of cobalt salt with a concentration of 0.05–0.2 mol / L; (b) Forming an aqueous solution of nickel salt with a concentration of 0.05–0.2 mol / L; (c) Formation of an aqueous solution of lanthanum salt with a concentration of 0.05–0.2 mol / L; (d) The formed aqueous solutions of cobalt salt, nickel salt, and lanthanum salt are mixed to obtain a mixed solution containing cobalt salt, nickel salt, and lanthanum salt; Steps (a), (b), and (c) are not in any particular order.

[0013] According to the preparation method of the present invention, preferably, in step 2), the carbon cloth is a pretreated carbon cloth. The pretreatment includes the following steps: immersing the initial carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid at a volume ratio of 1:2.5-3.5, soaking it at 15-40°C for 4-7 hours, then removing it and rinsing it repeatedly with water until the pH value is 6.5-7; then ultrasonically treating it in anhydrous ethanol and water for 15-30 minutes respectively, and then drying it to obtain the pretreated carbon cloth. The concentration of concentrated nitric acid is 65–68 wt%; the concentration of concentrated sulfuric acid is 92–98 wt%.

[0014] According to the preparation method of the present invention, preferably, in step 2), a graphite rod is used as the counter electrode and Ag / AgCl is used as the reference electrode; deposition is carried out for 30 to 50 minutes at a constant potential of -1.5V to -0.9V.

[0015] According to the preparation method of the present invention, preferably, step 2) further includes the following specific steps: after removing the working electrode with the precursor deposited on its surface, it is washed twice or more alternately with water and C1-C3 alkyl alcohols, and then dried; wherein, the C1-C3 alkyl alcohols are selected from methanol, ethanol and isopropanol.

[0016] According to the preparation method of the present invention, preferably, the calcination temperature is 350-450℃ and the calcination time is 1.5-4h.

[0017] In another aspect, the present invention also provides the application of the NiLaCo3O4 / / CC catalyst prepared according to the above-described method or the NiLaCo3O4 / / CC catalyst prepared according to the above-described method as an anode electrocatalyst in the acidic oxygen evolution reaction.

[0018] The NiLaCo3O4 / / CC catalyst of this invention can be used for acidic OER reactions, and it operates at 10 mA·cm⁻¹. -2 The oxygen evolution overpotential at the current density is low, less than or equal to 177 mV, for example, 176 mV. Furthermore, compared to Co3O4 / / CC, NiMnCo3O4 / / CC, NiCrCo3O4 / / CC, and NiCeCo3O4 / / CC catalysts, the NiLaCo3O4 / / CC catalyst exhibits a lower overpotential at a current density of 50 mA•cm⁻¹. -2 The oxygen evolution overpotential is relatively low, less than or equal to 403 mV, for example, 402 mV. The double-layer capacitance Cdl of the NiLaCo3O4 / / CC catalyst is relatively high, greater than or equal to 105 mF•cm. -2 The value reached 107.09 mF•cm. -2 This catalyst exhibits excellent electrocatalytic performance. The preparation method of this invention is beneficial for obtaining a stable NiLaCo3O4 / / CC catalyst. Attached Figure Description

[0019] Figure 1 The XRD patterns of each catalyst are shown.

[0020] Figure 2The images show the SEM, TEM, and EDS images of the catalyst. (a) is the SEM image of the NiLaCo3O4 / / CC catalyst; (b) and (c) are the HRTEM images of the NiLaCo3O4 / / CC catalyst; (d) is the HRTEM image of the Co3O4 / / CC catalyst; and (e) is the EDS elemental map of NiLaCo3O4 / / CC (referring to...). Figure 2 (The last two small images in the text).

[0021] Figure 3 The LSV curves for each catalyst are shown.

[0022] Figure 4 NiLaCo3O4 / / CC catalyst and Co3O4 / / CC catalyst at 10 mA•cm -2 and 50mA•cm -2 Oxygen evolution overpotential diagram under certain conditions.

[0023] Figure 5 The images show the Tafel curves for each catalyst.

[0024] Figure 6 The results show the double-layer capacitance of each catalyst.

[0025] Figure 7 Chronopotential curves of NiLaCo3O4 / / CC catalyst and Co3O4 / / CC catalyst.

[0026] Figure 8 The LSV curves of the NiLaCo3O4 / / CC catalyst after chronopotential testing are compared with those before testing.

[0027] Figure 9 SEM images of the NiLaCo3O4 / / CC catalyst after stability testing. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0029] Based on in-depth research into the activity and stability of Co3O4-based catalysts in acidic OER reactions and PEM electrolyzers, the inventors of this application constructed a series of NiMCo3O4 / / CC (M=Ce, La, Cr, Mn) catalysts on carbon cloth (CC) substrates using a combination of electrodeposition and low-temperature annealing. They also investigated the effects of Ni and La bimetallic doping elements on the catalyst phase composition, microstructure, electronic structure, oxygen vacancy concentration, and three-electrode acidic OER performance. Surprisingly, the inventors discovered that the NiLaCo3O4 / / CC catalyst exhibited the optimal electrocatalytic performance, thus completing this invention.

[0030] Terminology Explanation > Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although similar or equivalent methods and materials may be used in the implementation or testing of this invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference in their entirety. In case of any conflict, this specification and its included definitions shall prevail. Furthermore, materials, methods, preparation examples, and embodiments are exemplary only and are not intended to be limiting.

[0031] 34 Catalysts This invention provides a NiLaCo3O4 / / CC catalyst that can be used in acidic OER reactions with a low oxygen evolution overpotential. Compared with Co3O4 / / CC, NiMnCo3O4 / / CC, NiCrCo3O4 / / CC, and NiCeCo3O4 / / CC catalysts, this catalyst exhibits superior electrocatalytic performance.

[0032] The NiLaCo3O4 / / CC catalyst of the present invention contains Ni, La, Co, and O elements, which are uniformly distributed on the surface of carbon cloth (CC) and form nanosheet structures on the surface of the carbon cloth (CC). The raw materials used in the preparation of this catalyst include cobalt salt, nickel salt, and lanthanum salt, wherein the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt, and lanthanum in the lanthanum salt is 40:15-25:5.2-7.8. According to one embodiment of the present invention, the catalyst is obtained by first depositing a mixed solution containing cobalt salt, nickel salt, and lanthanum salt on the surface of carbon cloth by electrochemical deposition, and then calcining.

[0033] According to a specific embodiment of the present invention, the catalyst contains only Ni, La, Co, O and C elements and unavoidable impurities, wherein the C element originates from carbon cloth; and the Ni, La, Co and O elements are uniformly distributed on the surface of the carbon cloth.

[0034] In the X-ray diffraction pattern of the catalyst (using Cu Kα characteristic rays), characteristic diffraction peaks appear at diffraction angles 2θ of 36.56°±0.2°, 44.62°±0.2°, 59.22°±0.2° and 65.04°±0.2°, respectively. Among these characteristic diffraction peaks, the characteristic diffraction peak at 2θ of 36.56°±0.2° is the strongest. The diffraction peak at 2θ of 36.56°±0.2° belongs to the (311) crystal plane, and the lattice spacing of this crystal plane is greater than or equal to 0.295nm, preferably greater than or equal to 0.296, and more preferably 0.296~0.302; In this catalyst, Co 3+ / Co 2+ The ratio is less than or equal to 0.6, preferably less than or equal to 0.59, more preferably 0.58 to 0.59; the ratio of oxygen vacancy to lattice oxygen is greater than or equal to 1.5, preferably greater than or equal to 1.55, more preferably 1.55 to 1.65, and even more preferably 1.58 to 1.61.

[0035] In certain specific embodiments, the NiLaCo3O4 / / CC catalyst of the present invention exhibits a diffraction peak at 2θ of 36.56° belonging to the (311) crystal plane, which has a lattice spacing of 0.298 nm; in this catalyst, Co 3+ / Co 2+ The ratio is 0.584, and the ratio of oxygen vacancies to lattice oxygen is 1.589.

[0036] In this invention, the raw materials for preparing the catalyst include cobalt salt, nickel salt, and lanthanum salt. The molar ratio of cobalt in the cobalt salt, nickel in the nickel salt, and lanthanum in the lanthanum salt can be 40:15-25:5.2-7.8, preferably 40:18-22:6-7.5, more preferably 40:19-21:6.3-7.3, and even more preferably 40:19.5-20.5:6.6-6.8. For example, it can be 40:19.5:6.6, 40:20:6.67, 40:20:6.7, 40:20.5:6.67, or 40:20:6.8.

[0037] Preparation method> The preparation method of the NiLaCo3O4 / / CC catalyst of the present invention includes: (1) a step of forming a mixed solution containing cobalt salt, nickel salt and lanthanum salt; (2) an electrochemical deposition step; and (3) a calcination step. Optionally, it also includes a carbon cloth pretreatment step. The carbon cloth pretreatment step and the step of forming a mixed solution containing cobalt salt, nickel salt and lanthanum salt can be performed in any order.

[0038] The following is a detailed description.

[0039] Steps for forming a mixed solution containing cobalt salt, nickel salt and lanthanum salt In this invention, a mixed solution containing cobalt salt, nickel salt, and lanthanum salt is formed; wherein the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt, and lanthanum in the lanthanum salt is 40:15-25:5.2-7.8. This is beneficial for obtaining Ni- and La-doped catalysts with better electrocatalytic performance.

[0040] In this invention, the cobalt salt is cobalt nitrate. The nickel salt is selected from one or more of nickel nitrate, nickel sulfate, nickel chloride, and nickel acetate, preferably nickel nitrate. The lanthanum salt is selected from one or more of lanthanum nitrate, lanthanum sulfate, lanthanum chloride, and lanthanum acetate, preferably lanthanum nitrate. The cobalt salt, nickel salt, and lanthanum salt may or may not contain water of crystallization.

[0041] In this invention, the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt, and lanthanum in the lanthanum salt is preferably 40:18–22:6–7.5, more preferably 40:19–21:6.3–7.3, and even more preferably 40:19.5–20.5:6.6–6.8. For example, it can be 40:19.5:6.6, 40:20:6.67, 40:20:6.7, 40:20.5:6.67, or 40:20:6.8. This is beneficial for obtaining Ni- and La-doped catalysts with better electrocatalytic performance.

[0042] In some implementations, step 1) includes the following specific steps: (a) Formation of an aqueous solution of cobalt salt with a concentration of 0.05–0.2 mol / L; (b) Forming an aqueous solution of nickel salt with a concentration of 0.05–0.2 mol / L; (c) Formation of an aqueous solution of lanthanum salt with a concentration of 0.05–0.2 mol / L; (d) The formed aqueous solutions of cobalt salt, nickel salt, and lanthanum salt are mixed to obtain a mixed solution containing cobalt salt, nickel salt, and lanthanum salt; Steps (a), (b), and (c) are not in any particular order.

[0043] In step (a), the concentration of the cobalt salt aqueous solution is preferably 0.07 to 0.17 mol / L, more preferably 0.09 to 0.15 mol / L, for example, 0.09 mol / L, 0.1 mol / L, 0.11 mol / L, 0.12 mol / L, 0.13 mol / L, 0.14 mol / L, or 0.15 mol / L.

[0044] In step (b), the concentration of the nickel salt aqueous solution is preferably 0.07 to 0.17 mol / L, more preferably 0.09 to 0.15 mol / L, for example, 0.09 mol / L, 0.1 mol / L, 0.11 mol / L, 0.12 mol / L, 0.13 mol / L, 0.14 mol / L, or 0.15 mol / L.

[0045] In step (c), the concentration of the lanthanum aqueous solution is preferably 0.07–0.17 mol / L, more preferably 0.09–0.15 mol / L, for example, 0.09 mol / L, 0.1 mol / L, 0.11 mol / L, 0.12 mol / L, 0.13 mol / L, 0.14 mol / L, or 0.15 mol / L.

[0046] In this invention, the concentrations of the cobalt salt aqueous solution, nickel salt aqueous solution, and lanthanum salt aqueous solution can be the same or different. According to one embodiment of the invention, the concentrations of the cobalt salt aqueous solution, nickel salt aqueous solution, and lanthanum salt aqueous solution are the same, all ranging from 0.1 to 0.12 mol / L.

[0047] Pretreatment steps for carbon cloth Carbon cloth is used as a working electrode in electrochemical deposition. During electrochemical deposition, the carbon cloth is pretreated. The pretreatment includes the following steps: immersing the initial carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid at a volume ratio of 1:2.5–3.5 at 15–40°C for 4–7 h; then removing it and rinsing it repeatedly with water until the pH value reaches 6.5–7; next, ultrasonically treating it in anhydrous ethanol and water for 15–30 min respectively, followed by drying to obtain the pretreated carbon cloth; wherein the concentration of concentrated nitric acid is 65–68 wt% and the concentration of concentrated sulfuric acid is 92–98 wt%. This facilitates the uniform deposition of cobalt salts, nickel salts, and lanthanum salts on the surface of the carbon cloth.

[0048] In this invention, the volume ratio of concentrated nitric acid to concentrated sulfuric acid can be 1:2.5–3.5, preferably 1:2.8–3.3, more preferably 1:2.9–3.2, and even more preferably 1:3–3.1. The soaking time is preferably 4.5–6.5 h, more preferably 5–6 h. The soaking temperature can be room temperature. After soaking, the carbon cloth is removed and repeatedly rinsed with water until the pH of the washing solution is 6.5–7, preferably 7. After rinsing, the washed carbon cloth is first ultrasonically treated in anhydrous ethanol for 15–30 min, preferably 20–25 min, and then ultrasonically treated in water for 15–30 min, preferably 20–25 min. The water used can be deionized water, purified water, or distilled water. Finally, it can be dried in a vacuum drying oven at a temperature of 40–90°C, preferably 50–80°C. The drying time is 1–5 h, preferably 2–4 h.

[0049] Electrochemical deposition steps The mixed solution containing cobalt, nickel, and lanthanum salts, as described above, was used as the electrodeposition solution; carbon cloth was used as the working electrode, and the precursor was deposited on the surface of the working electrode by electrochemical deposition. This method is beneficial for obtaining a NiLaCo3O4 / / CC catalyst with better electrocatalytic performance.

[0050] According to one embodiment of the present invention, a graphite rod is used as the counter electrode and Ag / AgCl is used as the reference electrode; deposition is carried out for 30 to 50 minutes at a constant potential of -1.5V to -0.9V. Preferably, the constant potential is -1.2V to -0.9V, more preferably -1.1V to -1.0V. The deposition time is preferably 35 to 45 minutes, more preferably 38 to 42 minutes, and even more preferably 40 to 41 minutes.

[0051] This invention further includes the following steps: After electrochemical deposition, the working electrode with the precursor deposited on its surface is removed. Then, the precursor on the surface of the working electrode is washed repeatedly with water and C1-C3 alkyl alcohols, followed by drying. The C1-C3 alkyl alcohols are selected from methanol, ethanol, and isopropanol. Ethanol is preferred among the C1-C3 alkyl alcohols. The alternating washing is performed at least twice, preferably at least three times, for example, three to five times. This removes surface impurities and unstable deposits, facilitating the uniform deposition of cobalt salts, nickel salts, and lanthanum salts, resulting in a NiLaCo3O4 / / CC catalyst with better electrocatalytic performance.

[0052] In this step, drying can be carried out in a vacuum drying oven. The drying temperature can be 40–100°C, preferably 45–80°C, more preferably 50–70°C. The drying time can be 2–12 h, preferably 4–10 h, more preferably 6–8 h.

[0053] Calcination steps The working electrode with the precursor deposited on its surface, obtained as described above, is calcined to obtain the NiLaCo3O4 / / CC catalyst. This method is beneficial for obtaining a catalyst with better electrocatalytic performance.

[0054] In this invention, calcination can be performed using a muffle furnace. The working electrode with the precursor deposited on its surface is placed in the muffle furnace and heated to the calcination temperature at a heating rate of 1.5–4.5 °C / min. The heating rate is preferably 1.8–4 °C / min, more preferably 2–3 °C / min. The calcination temperature can be 350–450 °C, preferably 380–430 °C, more preferably 390–420 °C, for example, 390 °C, 395 °C, 400 °C, 405 °C, 410 °C, 415 °C, or 420 °C. The calcination time can be 1.5–4 h, preferably 2–3 h, more preferably 2–2.5 h.

[0055] Applications > This invention also provides the application of the NiLaCo3O4 / / CC catalyst as described above, or the NiLaCo3O4 / / CC catalyst prepared according to the preparation method described above, as an anode electrocatalyst in the acidic oxygen evolution reaction. In particular, its application as an anode electrocatalyst in the acidic oxygen evolution reaction of water electrolysis to produce hydrogen.

[0056] In the electrochemical testing of the oxygen evolution reaction (OER) performance of the catalyst using a three-electrode system, the NiLaCo3O4 / / CC catalyst showed excellent performance at a current density of 10 mA•cm⁻¹. -2 The oxygen evolution overpotential is less than or equal to 177 mV, for example, 176 mV. The NiLaCo3O4 / / CC catalyst operates at a current density of 50 mA•cm⁻¹. -2 The oxygen evolution overpotential is less than or equal to 403 mV, for example, 402 mV. The double-layer capacitance Cdl of the NiLaCo3O4 / / CC catalyst reaches 105 mF•cm. -2 For example, it reaches 107.09 mF•cm. -2 Compared with Co3O4 / / CC catalysts, NiMnCo3O4 / / CC catalysts, NiCrCo3O4 / / CC catalysts, and NiCeCo3O4 / / CC catalysts, the NiLaCo3O4 / / CC catalyst of this invention exhibits better electrocatalytic activity.

[0057] Test Methods > XRD was performed using a Rigaku Miniflex 600 X-ray diffractometer (Japan). The X-ray source was Cu-palladium. The operating voltage was 40 kV, the operating current was 15 mA, the diffraction wavelength was 0.15406 nm, the scanning range 2θ was 10°–90°, and the scanning speed was 5° / min. SEM and EDS were performed using a JEOL JSM-7200F scanning electron microscope (Japan). TEM was performed using a FEIF F20 high-power transmission electron microscope (USA).

[0058] <Partial Source of Raw Materials> The carbon cloth was purchased from Suzhou Shengernuo Technology Co., Ltd., and its brand name is WOS1011.

[0059] Preparation Example 1 The size is 1×1.5 cm 2The initial carbon cloth was immersed in a mixed solution of concentrated nitric acid (68 wt%) and concentrated sulfuric acid (98 wt%) at a volume ratio of 1:3 for 5 h at room temperature. Then, the carbon cloth was removed and repeatedly rinsed with deionized water until the pH reached 7. Next, the carbon cloth was ultrasonically treated in anhydrous ethanol and deionized water for 20 min each, and finally dried in a vacuum drying oven to obtain the pretreated carbon cloth.

[0060] Example 1 Prepare a 0.1 mol / L aqueous solution of cobalt nitrate hexahydrate (Co(NO3)2•6H2O). Prepare a 0.1 mol / L aqueous solution of nickel nitrate hexahydrate (Ni(NO3)2•6H2O). Prepare a 0.1 mol / L aqueous solution of lanthanum nitrate hexahydrate (La(NO3)3•6H2O).

[0061] The 40 mL cobalt nitrate aqueous solution, 20 mL nickel nitrate aqueous solution, and 6.67 mL lanthanum nitrate aqueous solution prepared above were mixed to obtain a mixed solution containing cobalt salt, nickel salt, and lanthanum salt.

[0062] A three-electrode system was used to prepare the precursor via electrochemical deposition, as follows: the pretreated carbon cloth from Preparation Example 1 was used as the working electrode, a graphite rod as the counter electrode, and Ag / AgCl as the reference electrode. The mixed solution containing cobalt, nickel, and lanthanum salts prepared above was used as the electrodeposition solution. The electrodeposition reaction was carried out at a constant potential of -1.0 V for 40 min, depositing the precursor on the surface of the working electrode.

[0063] The working electrode with the precursor deposited on its surface was taken out and washed 5 times alternately with deionized water and ethanol to remove surface impurities and unstable deposits. Then it was dried at 50°C for 8 hours to obtain the dried working electrode with the precursor deposited on its surface.

[0064] The dried working electrode with the precursor deposited on its surface was placed in a muffle furnace and heated to 400℃ at a heating rate of 2℃ / min, and calcined at 400℃ for 2 h to obtain the NiLaCo3O4 / / CC catalyst.

[0065] Preparation of Comparative Example 1 - Co3O4 / / CC Catalyst Cobalt nitrate hexahydrate (Co(NO3)2•6H2O) was prepared into a 0.1 mol / L cobalt nitrate solution, 20 mL of which was used as the electrodeposition solution. The pretreated carbon cloth obtained according to the pretreatment steps of Preparation Example 1 was used as the working electrode, a graphite rod as the counter electrode, and Ag / AgCl as the reference electrode. Using this three-electrode system, the reaction was carried out at a constant potential of -1.0 V for 40 min, depositing the Co3O4 precursor on the surface of the working electrode.

[0066] The working electrode with the precursor deposited on the surface of Co3O4 was taken out and washed 5 times alternately with deionized water and ethanol to remove surface impurities and unstable deposits. Then it was dried at 50°C for 8 hours to obtain the dried working electrode with the precursor deposited on the surface of Co3O4.

[0067] The working electrode with the dried precursor deposited on its surface was placed in a muffle furnace and then heated to 400°C at a heating rate of 2°C / min, and calcined at 400°C for 2 h to obtain the Co3O4 / / CC catalyst.

[0068] Preparation of Comparative 2-NiMnCo3O4 / / CC Catalyst Except for the following parameter settings, the catalyst is the same as in Example 1: manganese nitrate tetrahydrate (Mn(NO3)2•4H2O) is used instead of lanthanum nitrate hexahydrate. The resulting catalyst is denoted as NiMnCo3O4 / / CC catalyst.

[0069] Preparation of Comparative 3-NiCrCo3O4 / / CC Catalyst Except for the following parameter settings, the catalyst is the same as in Example 1: chromium nitrate nonahydrate (Cr(NO3)3•9H2O) is used instead of lanthanum nitrate hexahydrate. The resulting catalyst is denoted as NiCrCo3O4 / / CC catalyst.

[0070] Preparation of Comparative 4-NiCeCo3O4 / / CC Catalyst Except for the following parameter settings, the catalyst is the same as in Example 1: cerium nitrate hexahydrate (Ce(NO3)3•6H2O) is used instead of lanthanum nitrate hexahydrate. The resulting catalyst is denoted as NiCeCo3O4 / / CC catalyst.

[0071] Preparation of comparative 5-NiCo3O4 / / CC catalyst Except for the following parameter settings, the rest is the same as in Example 1: Lanthanum nitrate hexahydrate is removed.

[0072] Experimental Example 1. XRD tests of each catalyst The catalyst products of Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 were characterized by X-ray diffraction (XRD). The results are as follows: Figure 1 As shown.

[0073] Depend on Figure 1It can be seen that the NiLaCo3O4 / / CC catalyst exhibits diffraction peaks at 2θ values ​​of 36.56°, 44.62°, 59.22°, and 65.04°, respectively. These diffraction peaks perfectly match the standard PDF card (PDF#74-2120) for Co3O4. Among these diffraction peaks, the peak at 2θ of 36.56° is the strongest, belonging to the (311) crystal plane. The diffraction peak at 2θ of 44.62° belongs to the (400) crystal plane. The diffraction peak at 2θ of 59.22° belongs to the (511) crystal plane. The diffraction peak at 2θ of 65.04° belongs to the (440) crystal plane. It is worth noting that, apart from the carbon peak corresponding to the carbon cloth support, no additional diffraction peaks related to the dopant element or its oxide were observed in the XRD patterns of the four catalyst samples, indicating that the doping amount was not excessive and no independent crystalline phase was formed. Furthermore, the diffraction angle corresponding to the (311) crystal plane in the NiLaCo3O4 / / CC catalyst shifted slightly from 36.64° (2θ) to 36.56° (2θ) of the Co3O4 / / CC catalyst, indicating a shift towards a lower angle. This suggests that Ni and La ions have been successfully incorporated into the Co3O4 lattice, causing lattice expansion. The inventors believe that this phenomenon should be attributed to La. 3+ The ionic radius is greater than that of Co. 3+ and Co 2+ The ionic radius of La 3+ Ni tends to occupy octahedral sites 2+ They tend to occupy tetrahedral sites, leading to an increase in interplanar spacing.

[0074] 2. Characterization by SEM, TEM and EDS To determine the microstructure of the catalysts, SEM and TEM were used to characterize the microstructure of the NiLaCo3O4 / / CC catalyst and the Co3O4 / / CC catalyst. Figure 2 In the image, (a) is the SEM image of the NiLaCo3O4 / / CC catalyst, (b) and (c) are the HRTEM images of the NiLaCo3O4 / / CC catalyst, (d) is the HRTEM image of the Co3O4 / / CC catalyst, and (e) is the EDS elemental diagram of the NiLaCo3O4 / / CC catalyst.

[0075] Depend on Figure 2 As shown in (a), the nanosheet structure is uniformly distributed on the carbon cloth, which provides a large surface area for catalysis.

[0076] Depend on Figure 2As shown in (b) and (c), the NiLaCo3O4 / / CC catalyst has a clearly visible (311) crystal plane with a lattice spacing of 0.298 nm. This is consistent with the XRD results, where the diffraction peak at 36.56° corresponding to the (311) crystal plane of the NiLaCo3O4 / / CC catalyst is shifted by a smaller angle compared to the diffraction peak at 36.64° corresponding to the (311) crystal plane of the Co3O4 / / CC catalyst, indicating lattice spacing expansion. Furthermore, the presence of slight lattice distortion and localized atomic disorder also suggests the incorporation of Ni and La into the Co3O4 lattice. Figure 2 As shown in (d), the undoped Co3O4 / / CC catalyst has a complete crystal structure with a clearly visible (311) crystal plane and a lattice spacing of 0.258 nm, which is consistent with the strongest peak corresponding to the (311) crystal plane in the XRD test results.

[0077] like Figure 2 As shown in (e), the EDS elemental distribution diagram shows that Ni, La, Co and O elements are present in the NiLaCo3O4 / / CC catalyst, and Ni, La, Co and O elements are uniformly distributed on the carbon cloth surface, confirming that Ni and La doped nanosheet Co3O4 is uniformly distributed on the carbon cloth.

[0078] 3. Catalyst valence state analysis To further investigate the elemental composition and chemical valence states of the Co3O4 / / CC and NiLaCo3O4 / / CC catalysts, a suitable amount of sample was scraped from the carbon cloth (CC) support for X-ray photoelectron spectroscopy (XPS) analysis. The binding energies of all elements in the XPS spectra were corrected using the standard C1s binding energy (284.80 eV).

[0079] The XPS full spectrum of the Co3O4 / / CC catalyst showed Co, O, and C elements, but no other impurity elements. Similarly, the XPS full spectrum of the NiLaCo3O4 / / CC catalyst showed Ni, La, Co, O, and C elements, but no other impurity elements, consistent with previous XRD and EDS results.

[0080] High-resolution Ni 2p XPS spectra of the NiLaCo3O4 / / CC catalyst at 855.28 / 873.48 eV and 851.88 / 871.88 eV correspond to Ni 3+ and Ni 2+ Characteristic peaks. The results indicate that the introduction of Ni can modulate the local electronic environment and may participate in the redistribution of interfacial charge, thereby improving interfacial charge transport behavior. In the high-resolution 3d spectrum of La, the peaks at 834.78 / 851.48 eV exhibit characteristic La... 3+ Because of La3+ A larger ionic radius makes it easier to induce lattice expansion and changes in the local coordination environment, thus providing conditions for defect structure modulation and framework stability enhancement.

[0081] The high-resolution Co2p spectra of the Co3O4 / / CC catalyst and the NiLaCo3O4 / / CC catalyst show that both samples exhibit typical Co2p characteristics. 3 / 2 and Co2p 1 / 2 Spin orbital double peaks and corresponding satellite peaks. For NiLaCo3O4 / / CC catalysts, Co2p 3 / 2 China Co 3+ and Co 2+ The peaks are located at 779.88 eV and 781.38 eV, respectively, Co2p 1 / 2 China Co 3+ and Co 2+ The peaks are located at 794.88 eV and 796.38 eV, respectively. Compared with the Co3O4 / / CC catalyst, the Co 2p peak of the NiLaCo3O4 / / CC catalyst is generally shifted towards lower binding energies, where the 2p peak is... 3 / 2 Co in orbit 3+ and Co 2+ The negative shifts of approximately 0.3 eV and 0.4 eV, respectively, indicate that Ni and La co-doping increases the electron cloud density around the Co sites, altering the local electronic environment of Co. Further fitting results show that the Co... 3+ / Co 2+ The ratio was 0.584, lower than the 0.671 for the Co3O4 / / CC catalyst. This result indicates that bimetallic co-doping did not simply follow the method of continuously increasing Co in single-element doping systems. 3+ Instead of regulating the proportion through a specific pathway, it reconstructs the valence distribution of Co sites to achieve a more appropriate Co ratio. 3+ / Co 2+ This more moderate valence distribution is more conducive to achieving a balance between active site regulation and structural stability maintenance.

[0082] The high-resolution O1s XPS spectra of the Co3O4 / / CC and NiLaCo3O4 / / CC catalysts show that the O1s orbitals of both samples are split into peaks representing lattice oxygen (O2). L ), oxygen vacancy (O V ), surface adsorbed oxygen (OH), Co3O4 / / CC catalyst oxygen vacancies (O) V ) and lattice oxygen (O LThe oxygen vacancy to lattice oxygen ratio of the NiLaCo3O4 / / CC catalyst is 0.721, and 1.589, indicating that Ni and La co-doping induces oxygen vacancy generation. The lattice expansion and local strain accumulation caused by the introduction of La, along with the modulation of the electronic structure by Ni, jointly promote the generation of oxygen vacancies in the Co-O framework. This result does not imply that a higher number of defects is always more beneficial, but rather demonstrates that bimetallic synergistic doping achieves effective control over the concentration and local distribution of oxygen vacancies. The inventors believe that an appropriate oxygen vacancy concentration helps optimize the adsorption behavior of oxygen-containing intermediates and enhance interfacial charge transfer, in conjunction with a suitable Co... 3+ / Co 2+ By coupling proportions, a valence-defect synergistic structure that is more conducive to the unification of activity and stability of acidic OERs can be constructed.

[0083] 4. Analysis of the acidic OER performance of each catalyst in the three-electrode system 4.1 Electrochemical Testing To systematically evaluate the oxygen evolution reaction (OER) performance of the catalysts, electrochemical tests were performed using a three-electrode system. In this system, the working electrode was carbon cloth (as the anode), the counter electrode was a graphite rod, and the reference electrode was Ag / AgCl. Each catalyst was used as the anode catalyst. To improve accuracy and avoid interference from oxidation peaks in the linear sweep voltammetry (LSV) curves, measurements were performed in reverse sweep mode within the potential range of 1.559–0.959 V (vs. Ag / AgCl). Results are shown below. Figure 3 , Figure 4 and Figure 5 . Figure 3 The LSV curves for each catalyst sample are shown. Figure 4 For each catalyst sample at 10 mA•cm -2 and 50mA•cm -2 Overpotential under certain conditions. Figure 3 and Figure 4 The study included testing of the NiCo3O4 / / CC catalyst. Figure 5 This is a Tafel curve. Figure 4 , Figure 5 All overpotentials in the above are oxygen evolution overpotentials.

[0084] like Figure 3 As shown, to achieve the same current density of 10 mA·cm -2 At that time, the NiLaCo3O4 / / CC catalyst requires the lowest potential.

[0085] like Figure 4 As shown, the NiLaCo3O4 / / CC catalyst at a current density of 10 mA•cm -2The oxygen evolution overpotential at that time was 176 mV, which is significantly better than the oxygen evolution overpotential of 189 mV for NiCeCo3O4 / / CC catalyst, significantly better than the oxygen evolution overpotential of 244 mV for NiMnCo3O4 / / CC catalyst, significantly better than the oxygen evolution overpotential of 318 mV for NiCrCo3O4 / / CC catalyst, significantly better than the oxygen evolution overpotential of 355 mV for NiCo3O4 / / CC catalyst, and significantly better than the oxygen evolution overpotential of 414 mV for Co3O4 / / CC catalyst.

[0086] like Figure 4 As shown, the NiLaCo3O4 / / CC catalyst at a current density of 50 mA•cm -2 The oxygen evolution overpotential at that time was 402 mV, which was significantly better than the oxygen evolution overpotential of 426 mV for NiCeCo3O4 / / CC catalyst, significantly better than the oxygen evolution overpotential of 437 mV for NiMnCo3O4 / / CC catalyst, significantly better than the oxygen evolution overpotential of 522 mV for NiCrCo3O4 / / CC catalyst, significantly better than the oxygen evolution overpotential of 512 mV for NiCo3O4 / / CC catalyst, and significantly better than the oxygen evolution overpotential of 546 mV for Co3O4 / / CC catalyst.

[0087] The above results indicate that the NiLaCo3O4 / / CC catalyst exhibits optimal electrocatalytic performance. The inventors speculate that this is due to the presence of Co at octahedral sites. 3+ Ni is the main active site. 2+ ionic radius and Co 2+ Consistent, Ni 2+ It tends to occupy tetrahedral sites, which can effectively regulate the electronic structure of cobalt atoms and promote Co... 2+ To Co 3+ The transformation increases the number of active sites; simultaneously, the generation of an appropriate amount of oxygen vacancies further improves the adsorption behavior of oxygen-containing intermediates on the catalyst surface and reduces interfacial electron transport resistance, thus improving the interaction with Co. 3+ They synergistically promote the catalytic reaction.

[0088] The Tafel slope is an important kinetic parameter reflecting the intrinsic activity of a catalyst. A smaller value indicates a faster increase in current density per unit overpotential, implying more efficient charge transfer kinetics. For example... Figure 5 As shown, the Tafel slope of NiLaCo3O4 / / CC is the lowest, at only 57.5 mV•dec. -1 This indicates that it possesses the fastest reaction kinetics.

[0089] 4.2 Analysis of Electric Double Layer Capacitance (Cdl) and Electrochemical Active Surface Area (ECSA) Electrochemical active surface area (ECSA) is an important indicator reflecting the catalytic activity of a material, and its value is directly proportional to the electrochemical double-layer capacitance (Cdl). To further investigate the OER performance of various catalysts, cyclic voltammetry (CV) tests were performed on five catalyst samples within the non-Radida potential range at different scan rates, and the Cdl values ​​of each catalyst were obtained by fitting the results. The tests were conducted within ±50 mV around the open circuit potential (OCP). The measurements were performed at 20, 40, 60, 80, and 100 mV•s. -1 Cdl was calculated from the CV curves at five scan rates. Figure 6 The fitting results show that the Cdl of the Co3O4 / / CC catalyst is 9.33 mF•cm. -2 The Cdl of the NiCrCo3O4 / / CC catalyst is 14.64 mF•cm. -2 The Cdl of the NiMnCo3O4 / / CC catalyst is 61.1 mF•cm. -2 The Cdl of the NiCeCo3O4 / / CC catalyst is 82.1 mF•cm. -2 The NiLaCo3O4 / / CC catalyst exhibited the highest Cdl, reaching 107.09 mF•cm. -2 The electrochemical surface area (ECSA) was obtained from Cdl, as shown in Table 1, with units of square centimeters (cm²). 2 ).

[0090] Table 1

[0091] As shown in the table, compared with the Co3O4 / / CC catalyst, NiCrCo3O4 / / CC catalyst, NiMnCo3O4 / / CC catalyst, and NiCeCo3O4 / / CC catalyst, the NiLaCo3O4 / / CC catalyst has the largest electrochemical surface area (ECSA). The inventors speculate that this is because the nanosheet structure of the NiLaCo3O4 / / CC catalyst provides a larger effective surface area for catalysis. 2+ Doping modulates Co 3+ / Co 2+ The ratio increases the number of reactive sites, and the generated oxygen vacancies react with Co. 3+ The synergistic effect enhances the interfacial charge adsorption capacity and the double-layer capacitance storage capacity.

[0092] 4.3 CP Test Stability is a key parameter for evaluating the performance of catalysts in actual electrolysis processes, reflecting their ability to maintain catalytic activity over long-term operation. For example... Figure 7 As shown, at 10 mA•cm -2Chronopotential (CP) tests were conducted on the Co3O4 / / CC and NiLaCo3O4 / / CC catalysts at different current densities for 100 h. The results showed that the NiLaCo3O4 / / CC catalyst exhibited only a potential fluctuation of approximately 87 mV throughout the test period, which was superior to the Co3O4 / / CC catalyst, demonstrating better stability. Furthermore, as... Figure 8 As shown, by comparing the LSV curves of NiLaCo3O4 / / CC catalyst before and after CP testing, it was found that its OER performance did not change significantly, and the current density curves almost overlapped. Figure 8 In this context, the After CP curve refers to the LSV curve after 100 hours of chronopotential (CP) testing. Figure 9 This is a SEM image of the NiLaCo3O4 / / CC catalyst after stability testing. Figure 9 As shown, the wrinkled, lamellar structure of the catalyst remains clearly visible after testing, indicating that the catalyst possesses excellent structural and performance durability. These results confirm that the NiLaCo3O4 / / CC catalyst not only exhibits high catalytic activity but also possesses long-term stability, making it a highly efficient OER catalyst with application potential. This is likely because La doping primarily occupies octahedral sites, and the interaction between La and O forms strong ionic bonds, further forming a rigid framework that stabilizes the crystal lattice. This suppresses structural collapse and reduces ion dissolution during the OER reaction.

[0093] This invention is not limited to the above-described embodiments. Any modifications, improvements, or substitutions that can be conceived by those skilled in the art without departing from the essential content of this invention fall within the scope of this invention.

Claims

1. A NiLaCo3O4 / / CC catalyst, characterized in that, The catalyst contains Ni, La, Co and O elements, which are uniformly distributed on the surface of the carbon cloth and form a nanosheet structure on the surface of the carbon cloth. The raw materials used in the preparation of this catalyst include cobalt salt, nickel salt and lanthanum salt, wherein the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt and lanthanum in the lanthanum salt is 40:15-25:5.2-7.

8.

2. The NiLaCo3O4 / / CC catalyst according to claim 1, characterized in that, The catalyst was obtained by first depositing a mixed solution containing cobalt salt, nickel salt and lanthanum salt on the surface of carbon cloth by electrochemical deposition, and then calcining it. In the X-ray diffraction pattern of the catalyst, characteristic diffraction peaks appear at 2θ of 36.56°±0.2°, 44.62°±0.2°, 59.22°±0.2° and 65.04°±0.2°, respectively. Among these characteristic diffraction peaks, the characteristic diffraction peak at 2θ of 36.56°±0.2° is the strongest. The diffraction peak at 2θ, which is 36.56°±0.2°, belongs to the (311) crystal plane, whose lattice spacing is greater than or equal to 0.295 nm. In this catalyst, Co 3+ / Co 2+ The ratio is less than or equal to 0.6, and the ratio of oxygen vacancies to lattice oxygen is greater than or equal to 1.

5.

3. The method for preparing the NiLaCo3O4 / / CC catalyst according to claim 1 or 2, characterized in that, Includes the following steps: 1) A mixed solution containing cobalt salt, nickel salt and lanthanum salt is formed; wherein the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt and lanthanum in the lanthanum salt is 40:15~25:5.2~7.8; 2) Using the mixed solution containing cobalt salt, nickel salt and lanthanum salt obtained in step 1) as the electrodeposition solution, and carbon cloth as the working electrode, a precursor is deposited on the surface of the working electrode by electrochemical deposition; then the working electrode with the precursor deposited on the surface is removed. 3) The working electrode with the precursor deposited on its surface obtained in step 2) is calcined to obtain the NiLaCo3O4 / / CC catalyst.

4. The preparation method according to claim 3, characterized in that, In step 1), the cobalt salt is cobalt nitrate, the nickel salt is nickel nitrate, and the lanthanum salt is lanthanum nitrate; the molar ratio of cobalt in the cobalt salt, nickel in the nickel salt, and lanthanum in the lanthanum salt is 40:18~22:6~7.

5.

5. The preparation method according to claim 3, characterized in that, Step 1) includes the following specific steps: (a) Formation of an aqueous solution of cobalt salt with a concentration of 0.05–0.2 mol / L; (b) Forming an aqueous solution of nickel salt with a concentration of 0.05–0.2 mol / L; (c) Formation of an aqueous solution of lanthanum salt with a concentration of 0.05–0.2 mol / L; (d) The formed aqueous solutions of cobalt salt, nickel salt, and lanthanum salt are mixed to obtain a mixed solution containing cobalt salt, nickel salt, and lanthanum salt; Steps (a), (b), and (c) are not in any particular order.

6. The preparation method according to claim 3, characterized in that, In step 2), the carbon cloth is a pre-treated carbon cloth. The pretreatment includes the following steps: immersing the initial carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid at a volume ratio of 1:2.5-3.5, soaking it at 15-40°C for 4-7 hours, then removing it and rinsing it repeatedly with water until the pH value is 6.5-7; then ultrasonically treating it in anhydrous ethanol and water for 15-30 minutes respectively, and then drying it to obtain the pretreated carbon cloth. The concentration of concentrated nitric acid is 65–68 wt%; the concentration of concentrated sulfuric acid is 92–98 wt%.

7. The preparation method according to claim 3, characterized in that, In step 2), a graphite rod is used as the counter electrode and Ag / AgCl is used as the reference electrode; deposition is carried out for 30 to 50 minutes at a constant potential of -1.5V to -0.9V.

8. The preparation method according to claim 7, characterized in that, Step 2) also includes the following specific steps: after removing the working electrode with the precursor deposited on its surface, wash it twice or more with water and C1-C3 alkyl alcohol alternately, and then dry it; wherein, the C1-C3 alkyl alcohol is selected from methanol, ethanol and isopropanol.

9. The preparation method according to claim 3, characterized in that, The calcination temperature is 350–450℃, and the calcination time is 1.5–4 h.

10. The application of the NiLaCo3O4 / / CC catalyst according to any one of claims 1 to 2 or the NiLaCo3O4 / / CC catalyst prepared by the preparation method according to any one of claims 3 to 9 as an anode electrocatalyst in the acidic oxygen evolution reaction.

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