Preparation method and application of high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial

Abstract

The present invention uses nickel foam with high conductivity as a substrate. First, a layered structure of Co2(OH)3Cl precursor material is grown on the nickel foam by a solvothermal method. Then, o-aminoterephthalic acid and the like are added as ligands, and a ligand conversion reaction is carried out by a solvothermal method to synthesize metal organic framework (MOF) nanosheets CoMOF-NH2 with an ultra-thin structure. Finally, a porous nanosheet Co3O4 / NC with efficient OER catalytic performance is obtained by controlled heat treatment in an inert atmosphere at high temperature. Co3O4 / NC only requires an overpotential of 235mV and 264mV in 1M KOH electrolysis to reach 10mA / cm 2 and 100mA / cm 2 The current density is very low, and the Tafel slope is only 80mV / dec. The performance remains stable after long-term use.

Description

Technical Field

[0001] The present invention relates to the fields of new materials technology and electrocatalysis, and belongs to the field of nanomaterials. Specifically, it relates to cobalt-based oxygen evolution electrocatalytic nanomaterials and their synthesis methods. The synthesized cobalt-based oxygen evolution electrocatalyst (Co3O4 / NC) has a novel structure and excellent electrochemical performance. Background Art

[0002] The increasing energy crisis and related environmental issues such as excessive burning of fossil fuels have triggered extensive research on clean and sustainable alternative energy sources. Recently, water electrolysis has become one of the most promising methods to achieve efficient energy conversion and storage in chemical form. As a half-reaction of water electrolysis, the oxygen evolution reaction (OER) involves a multi-electron transfer process and is associated with various renewable energy systems such as solar cells, metal-air batteries, and fuel cells. However, the kinetics of the OER are sluggish and high overpotentials are required to drive the reaction. To date, metal oxides are the most active and durable electrocatalysts for the OER, among which precious metal iridium (Ir) and ruthenium (Ru) oxides are considered to be the best OER catalysts in acidic and alkaline media. However, their high price and element scarcity have greatly hindered their large-scale application. Therefore, it is highly desirable to design and develop efficient, low-cost, and earth-abundant OER electrocatalysts with excellent catalytic activity and durability.

[0003] For heterogeneous electrocatalytic processes such as the oxygen evolution reaction (OER), the activity of electrocatalysts depends not only on their intrinsic composition and conductivity but also on the electrode geometry, structural porosity, accessible active sites, and interfacial coupling of the catalysts used. Therefore, directly constructing electrocatalysts by incorporating active materials onto three-dimensional porous conductive substrates has attracted significant attention in electrocatalytic reactions. Compared with two-dimensional planar electrocatalysts fabricated on glassy carbon electrodes, electrodes with three-dimensional porous conductive structures have several key advantages: excellent conductivity can facilitate electron transport; large electrochemically active surfaces and fully exposed active sites can enhance electrocatalytic activity, thereby accelerating the reaction rate of the electrocatalyst; and porous frameworks facilitate electrolyte penetration and gas bubble detachment. Although many 3D porous electrocatalysts have been developed and exhibit excellent electrocatalytic performance for OER, placing metal-organic frameworks (MOFs) on conductive substrates to construct 3D electrodes for OER catalysis remains a significant challenge.

[0004] Using MOFs as precursors, simple pyrolysis can convert them into metal-carbon-nitrogen materials with highly efficient electrocatalytic properties. The metal-carbon-nitrogen structure and the chemical state of the nitrogen therein can be tuned by selecting appropriate nitrogen-containing precursors and adjusting the pyrolysis temperature. Synthesizing nanomaterial catalysts with uniform shapes and large specific surface areas, thereby exposing a large number of catalytically active sites, remains a challenge. To this end, the present invention is proposed. Summary of the Invention

[0005] To address the shortcomings and deficiencies of the aforementioned prior art, the present invention provides a high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial. Its unique nanosheet structure, formed by interconnected nanoparticles, exposes a large number of OER active sites and significantly increases the contact area between the electrode material and the electrolyte, thereby improving electrocatalytic performance. The present invention synthesizes the cobalt-based nanocomposite material through a combined hydrothermal and calcination method. This preparation method is simple, efficient, and utilizes a rich source of raw materials at low cost. The resulting electrocatalytic material exhibits excellent electrochemical performance as an electrochemical oxygen evolution catalyst.

[0006] The present invention also provides a method for preparing the high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial and its application in electrocatalytic oxygen evolution.

[0007] The technical solutions of the present invention are as follows:

[0008] A high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial, which is composed of nano-Co3O4 grown on a nickel foam substrate and a composite of nitrogen-carbon materials (labeled as Co3O4 / NC), has a unique lamellar structure formed by Co3O4 nanoparticles interconnected by nitrogen-carbon. The thickness of the nanosheets is 4 to 7 nm.

[0009] According to the present invention, the X-ray diffraction (XRD) spectrum of the Co3O4 / NC composite material corresponds to the crystal structure of Co3O4 (card number JCPDS: 42-1467).

[0010] According to the present invention, the X-ray photoelectron spectroscopy test results of the high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial Co3O4 / NC show that it contains peaks of four components: C1s, O1s, Co2p, and N1s. In the Co2p region, there are two main peaks located at 779.72eV and 794.79eV corresponding to Co2p. 1 / 2 and Co2p 3 / 2 Corresponding to Co3O4 in Co2p 1 / 2 and Co2p 3 / 2In the C1s region, the spectrum shows that Co3O4 / NC contains CO, CN and C=C. This means that in addition to Co3O4, there are also abundant carbon and nitrogen structures in Co3O4 / NC. In the N1s region, the peak is located at 401.16eV, corresponding to the CN bond. In the O1S region, its peak positions are 529.48eV and 531.2eV, corresponding to O in Co3O4. The peak at 531.2eV in the O 1S spectrum corresponds to -OH, which is due to the hydroxyl groups adsorbed on the surface of the material during the XPS test.

[0011] According to the present invention, the preparation method of the above-mentioned high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial Co3O4 / NC is as follows Figure 1 As shown, the following steps are included:

[0012] (1) Pretreatment of nickel foam (NF) substrate: A 1 cm × 1 cm nickel foam block was ultrasonically treated in acetone for 20 minutes, then in 3 M hydrochloric acid solution for 15 minutes, and finally rinsed repeatedly with ethanol and deionized water, and finally dried in a vacuum drying oven at 60 ° C for 6 hours to obtain a clean nickel foam.

[0013] (2) The cobalt source and the surfactant are dissolved in a polar solvent, ultrasonicated for 15 minutes, and transferred to a high-pressure reactor. The nickel foam obtained in (1) is immersed in the above solution to carry out a hydrothermal reaction. The product is washed and dried to obtain a lamellar product 1 (Co2(OH)3Cl) grown on the surface of the nickel foam.

[0014] (3) The ligand is added to a polar solvent and ultrasonicated for 15 minutes to obtain a clear solution, which is then transferred to a high-pressure reactor. The product 1 is immersed in the solution and subjected to a hydrothermal reaction to cause ligand conversion. The product is washed and dried to obtain a product 2 (CoMOF-NH2) having MOF structural characteristics.

[0015] (4) Product 2 is further calcined at high temperature in an inert atmosphere to obtain high-performance Co3O4 / NC oxygen evolution electrocatalytic nanomaterials.

[0016] According to the present invention, preferably, the cobalt source in step (2) is cobalt nitrate, the surfactant is hexadecyltrimethylammonium bromide, and the hydrothermal reaction is carried out in a polytetrafluoroethylene high-pressure reactor.

[0017] According to the present invention, preferably, the polar solvent in step (2) is a mixed solvent of methanol and water, and the volume ratio of methanol to water is controlled at (4-6):1, most preferably 5:1.

[0018] According to the present invention, preferably, the molar ratio of the cobalt source to the surfactant in step (2) is controlled at (1-3):1, most preferably 1:1.

[0019] According to the present invention, preferably, the reaction temperature of the hydrothermal reaction in step (2) is 180° C., and the reaction time is 24 h; the reaction temperature of the hydrothermal reaction in step (3) is 120° C., and the reaction time is 24 h.

[0020] According to the present invention, preferably, the ligand in step (3) is o-aminoterephthalic acid, and the molar ratio of the cobalt source to the ligand is controlled at (3-6):1, most preferably 3:1.

[0021] According to the present invention, preferably, the polar solvent in step (3) is a mixed solvent of dimethylformamide (DMF) and water, and the volume ratio of DMF to water is controlled at (5-12):1, most preferably 8:1.

[0022] According to the present invention, preferably, the calcination temperature in step (4) is controlled at 500°C-800°C, most preferably 600°C.

[0023] According to the present invention, preferably, the calcination time in step (4) is controlled to be 5-10 hours, and the optimal time is 6 hours.

[0024] According to the present invention, preferably, the product 1 in step (2) is Co2(OH)3Cl, and the product 2 in step (3) is CoMOF-NH2.

[0025] According to the present invention, preferably, after the reaction is completed, the reaction is cooled to room temperature, repeatedly rinsed with deionized water for 5 times, and dried at 60° C. in a vacuum to obtain the Co 3 O 4 / NC electrocatalytic oxygen evolution nanomaterial.

[0026] The present invention also provides the use of the high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial in the electrolysis of water to produce oxygen.

[0027] A standard three-electrode system was used on an electrochemical workstation to test the oxygen production capacity of Co3O4 / NC electrocatalytic water decomposition. The specific test is as follows:

[0028] The polarization curves (LSV) and cyclic voltammetry (CV) curves were tested in 1 M KOH solution using a CHI 760E electrochemical workstation. Hg / HgO was used as the reference electrode and a 1 cm × 1 cm platinum sheet electrode was used as the counter electrode. Before each experiment, the electrolyte was pre-purged with nitrogen for 30 min to deoxygenate and eliminate interference. The scan rate was set to 5 m V / s.

[0029] Electrochemical impedance spectroscopy (EIS) was performed using a CHI 760E electrochemical workstation. Other test conditions were kept the same, and the frequency was set from 100,000 Hz to 0.01 Hz.

[0030] The Tafel plot is obtained by plotting the overpotential (η) against log(j), and the kinetic performance of the catalyst for electrocatalytic oxygen evolution is evaluated by calculating the Tafel slope.

[0031] All potential values ​​in the experiment were calibrated by a standard hydrogen electrode. The electrode potential calibration equation is:

[0032]

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] 1. The present invention prepares a high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial, which uses readily available and inexpensive raw materials and simple preparation conditions. The unique nanosheet material composed of interconnected nanoparticles in this material greatly increases the material's surface area, exposing more active sites and promoting electron transfer. Compared with bulk metal catalysts, porous sheet nanocatalysts are more attractive. The cobalt tetroxide nanoparticles in the material interact with the unique carbon-nitrogen structure, resulting in a uniform morphology, accelerating the electron transfer rate, and endowing it with higher OER catalytic activity and electrochemical stability.

[0035] 2. The linear scanning curve performance test of the present invention found that the cobalt-based electrocatalytic nanomaterial composed of uniform porous nanosheets has excellent oxygen evolution performance, especially compared with Co2(OH)3Cl, CoMOF-NH2, and commercial catalyst ruthenium oxide (RuO2). At the same current density, it can achieve high efficiency of oxygen evolution in the electrocatalytic process, so it has high application value in electrocatalytic hydrogen evolution. It has long-term stability and a current density of 100mAcm -2 When the overpotential is only 264mV. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart for the preparation of high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial Co3O4 / NC.

[0037] Figure 2 This is an SEM image of the cobalt-based oxygen evolution electrocatalyst (Co3O4 / NC) obtained in Example 3.

[0038] Figure 3 This is a TEM image of the cobalt-based oxygen evolution electrocatalyst (Co3O4 / NC) obtained in Example 3.

[0039] Figure 4 This is the HRTEM image of the cobalt-based oxygen evolution electrocatalyst (Co3O4 / NC) obtained in Example 3.

[0040] Figure 5These are XPS graphs of the cobalt-based oxygen evolution electrocatalyst (CoMOF-NH2) obtained in Example 2 and the cobalt-based oxygen evolution electrocatalyst (Co3O4 / NC) obtained in Example 3.

[0041] Figure 6 This is the LSV diagram of the performance test of cobalt-based oxygen evolution electrocatalytic nanomaterials in Experimental Example 2.

[0042] Figure 7 This is an overpotential bar chart of the performance test of cobalt-based oxygen evolution electrocatalytic nanomaterials in Experimental Example 2.

[0043] Figure 8 This is the Tafel slope diagram of the performance test of cobalt-based oxygen evolution electrocatalytic nanomaterials in Experimental Example 2.

[0044] Figure 9 This is the double-layer capacitance diagram of the cobalt-based oxygen evolution electrocatalytic nanomaterial performance test in Experimental Example 2.

[0045] Figure 10 This is the AC impedance diagram of the performance test of cobalt-based oxygen evolution electrocatalytic nanomaterials in Experimental Example 2.

[0046] Figure 11 This is the cyclic stability diagram of the performance test of cobalt-based oxygen evolution electrocatalytic nanomaterials in Experimental Example 2. DETAILED DESCRIPTION

[0047] The method for preparing a high-performance cobalt-based oxygen evolution electrocatalytic nanocomposite material according to the present invention is described in detail below with reference to specific embodiments and examples.

[0048] The raw materials used in the examples are all commercially available products. The main experimental reagents used are listed below: The following examples illustrate the present invention, which includes but is not limited to the following examples:

[0049] Cobalt chloride hexahydrate (CoCl2·6H2O, ≥99.9%), cetyltrimethylammonium bromide (CTAB, 99%), methanol (CH3OH, ≥99.5%), o-aminoterephthalic acid (BDC-NH2, ≥98%), N,N-dimethylformamide (DMF, 99.5%).

[0050] Example 1. Preparation of Cobalt-Based Oxygen Evolution Electrocatalyst Product 1 (Co2(OH)3Cl)

[0051] 1.5 mmol of CoCl2·6H2O and 1.5 mmol of cetyltrimethylammonium bromide (CTAB) were added to a mixture of 6 ml of deionized water and 30 ml of methanol. The mixture was sonicated for 15 minutes to obtain a clear solution, which was then transferred to a 50 ml polytetrafluoroethylene autoclave. A 1 cm × 1 cm area of ​​pretreated nickel foam was immersed in the solution and reacted at 180°C for 24 hours. The resulting nickel foam was repeatedly rinsed with deionized water and finally dried in a vacuum oven at 60°C for 2 hours to obtain a nickel foam-supported lamellar product with the structure of Co2(OH)3Cl.

[0052] Example 2. Preparation of Cobalt-based Oxygen Evolution Electrocatalyst Product 2 (CoMOF-NH2)

[0053] 0.5 mmol of o-aminoterephthalic acid (BDC-NH2) was placed in a 15 ml polytetrafluoroethylene autoclave, along with a mixture of 8 ml of DMF and 1 ml of deionized water. Ultrasonication was performed for 15 minutes to obtain a clear solution. The previously prepared nickel foam-supported Co2(OH)3Cl material was then immersed in this solution. The reaction tube was sealed and the ligand conversion reaction was carried out at 100°C for 24 hours. The layered MOF structure material supported on the nickel foam surface obtained by this solvothermal treatment was rinsed several times with deionized water and finally dried in a 60°C oven for 6 hours. The product is labeled CoMOF-NH2.

[0054] Example 3. Preparation of Cobalt-based Oxygen Evolution Electrocatalyst (Co3O4 / NC)

[0055] The layered MOF structure, CoMOF-NH2, was subjected to a controlled heat treatment under an argon atmosphere. The specific process was as follows: under an argon atmosphere (argon flow rate of 80 ml / min), it was first heated from room temperature to 600°C at a rate of 5° / min, then held at 600°C for 6 hours, and finally cooled to room temperature at a rate of -5°C / min to obtain Co3O4 / NC.

[0056] Test Example 1

[0057] The cobalt-based oxygen evolution electrocatalyst (Co3O4 / NC) obtained in Example 3 was characterized and tested as follows:

[0058] Scanning electron microscopy (SEM): The scanning electron microscopy image of the cobalt-based oxygen evolution catalyst (Co3O4 / NC) is as follows Figure 2 As shown, Co3O4 / NC nanomaterials are nanosheet materials composed of interconnected nanoparticles, which is beneficial to the increase of specific surface area and active sites.

[0059] Transmission electron microscopy (TEM): The transmission electron microscopy image of the cobalt-based oxygen evolution catalyst (Co3O4 / NC) is as follows Figure 3As shown, the thickness of the nanosheet structure formed by the mutual interlacing is 4 to 7 nm, and there are a large number of pores between the nanoparticles that make up the nanosheet.

[0060] High-resolution transmission electron microscopy (HRTEM): The high-resolution transmission electron microscopy image of the cobalt-based oxygen evolution catalyst (Co3O4 / NC) is as follows: Figure 4 As shown, the lattice distance in the cobalt-based nanomaterial corresponds to Co3O4(220).

[0061] X-ray photoelectron spectroscopy (XPS): Figure 5 As shown in a, the peak shape of Co2p of Co3O4 / NC is very similar to the Co2p spectrum of standard Co3O4. And the binding energy positions of the Co2p peaks are 779.72eV and 794.79eV respectively, which further proves that this peak is the peak corresponding to Co2p in Co3O4. Figure 5 As shown in b, the C1s spectrum of Co3O4 / NC contains CO, CN and C=C. This shows that in addition to Co3O4, there are also rich carbon-nitrogen structures in Co3O4 / NC. Co3O4 and carbon-nitrogen composite materials produce a synergistic effect, which is also an important reason for the excellent catalytic performance of the catalyst. Figure 5 In c, the CN bond contained in the N1s spectrum of Co3O4 / NC is consistent with its C1s spectrum. The CN bond here is the CN bond in nitrogen-doped graphitic carbon, which also proves that Co3O4 / NC contains a small amount of graphitized carbon. Figure 5 d. The high-resolution spectrum of O1S in Co3O4 / NC further reveals an O1S peak at a binding energy of 529.48 eV, further confirming the presence of Co3O4 in the catalyst. The O1S peak at 531.2 eV, representing the -OH group, is due to hydroxyl groups adsorbed on the surface during XPS analysis. Co3O4 / NC is a composite catalyst composed of Co3O4 and a carbon-nitrogen hybrid material.

[0062] Test Example 2

[0063] The performance test of the cobalt-based oxygen evolution electrocatalytic nanomaterial obtained in Example 3 is as follows:

[0064] The polarization curve (LSV) and cyclic voltammetry (CV) curves were measured using a CHI 760E electrochemical workstation in a 1M KOH solution, using Hg / HgO as the reference electrode and a 1cm×1cm platinum sheet electrode as the counter electrode. Before each experiment, the electrolyte was pre-purged with nitrogen for 30 minutes to remove oxygen and eliminate interference. The scan rate was set to 5mV / s. The oxygen evolution performance of the cobalt-based oxygen evolution electrocatalytic nanomaterial of Example 3 is shown in Figure 3. Figure 6 As shown, Figure 6Its polarization curve (LSV). Figure 7 The corresponding different electrocatalytic 2 and 100mA / cm 2 The bar chart of the overpotential corresponding to the current density. Figure 6 and Figure 7 It can be seen that the oxygen evolution performance of Co3O4 / NC electrocatalyst is better than that of CoMOF-NH2 and Co2(OH)3Cl.

[0065] The Tafel curve is obtained by plotting the overpotential (η) against log(j), and the kinetic performance of the electrocatalytic oxygen production of the catalyst is evaluated by the obtained Tafel slope. Figure 8 It can be seen that the cobalt-based electrocatalytic material has a smaller Tafel slope, which is 80m V / dec.

[0066] The current density versus scan rate curve of the electrocatalyst can reflect the double layer capacitance (C dI ) size. Figure 8 It can be seen that the cobalt-based oxygen evolution electrocatalyst has a large double-layer capacitance of 15.9mF / cm 2 .

[0067] The electrochemical impedance spectroscopy (EIS) was measured using a CHI 760E electrochemical workstation, with other test conditions kept the same and the frequency set from 100,000 Hz to 0.01 Hz. Figure 10 As shown by Figure 10 It can be seen that the cobalt-based oxygen evolution electrocatalyst has a small electron transfer resistance of 1.62Ω.

[0068] Long-term stability is one of the key parameters that determine the practical performance of an electrocatalyst. The stability of the Co3O4 / NC electrocatalyst of Example 3 was tested by chronopotentiometry.

[0069] Depend on Figure 11 It can be seen that the catalytic activity of the electrocatalyst is maintained for 24 hours, and the cobalt-based electrocatalytic nanomaterial has strong electrochemical stability in the oxygen evolution reaction.

[0070] The above examples illustrate that the cobalt-based oxygen evolution electrocatalytic nanomaterial is a porous nanosheet material composed of nanoparticles, which is conducive to exposing more catalytic active sites and increasing the contact area between the electrode material and the electrolyte, thereby having excellent performance in catalyzing oxygen evolution reaction by water electrolysis.

Claims

1. A high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial, characterized in that: The material is a composite of nano-Co3O4 grown on a nickel foam substrate and a nitrogen-carbon material, labeled Co3O4 / NC. It has a unique lamellar structure formed by interconnected Co3O4 nanoparticles through nitrogen-carbon hybrids, with the thickness of the nanosheets being 4 to 7 nm. The preparation method of the material includes the following steps: (1) Pretreatment of nickel foam (NF) substrate: a 1 cm × 1 cm nickel foam block was ultrasonically treated in acetone for 20 minutes, then in 3 M hydrochloric acid solution for 15 minutes, and finally rinsed repeatedly with ethanol and deionized water, and finally dried in a vacuum drying oven at 60 ° C for 6 hours to obtain a clean nickel foam; (2) Dissolve the cobalt source cobalt chloride and the surfactant hexadecyltrimethylammonium bromide in a polar solvent, ultrasonicate for 15 minutes, transfer to a high-pressure reactor, immerse the nickel foam obtained in (1) in the above solution, conduct a closed hydrothermal reaction, wash the product, and dry it to obtain a lamellar product 1 Co2(OH)3Cl grown on the surface of the nickel foam; (3) Add the ligand o-aminoterephthalic acid to a polar solvent, ultrasonicate for 15 minutes to obtain a clear solution, transfer it to a polytetrafluoroethylene-lined autoclave, immerse the product 1 in it, perform a hydrothermal reaction to convert its ligand, wash the product, and dry it to obtain nano-sheet-like product 2 CoMOF-NH2 with metal organic framework (MOF) structural characteristics; (4) Product 2 is further calcined at high temperature in an inert atmosphere to obtain high-performance Co3O4 / NC oxygen evolution electrocatalytic nanomaterials.

2. The high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial according to claim 1, characterized in that: The X-ray diffraction (XRD) spectrum of the Co3O4 / NC composite material corresponds to the crystal structure card number of Co3O4 JCPDS: 42-1467; The X-ray photoelectron spectrum of the high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial shows peaks of four components: C1s, O1s, Co2p, and N1s.

3. The high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial according to claim 1, characterized in that The molar ratio of the cobalt source cobalt chloride and the surfactant cetyltrimethylammonium bromide in step (2) is controlled at (1-3):1, the polar solvent is a mixed solvent of methanol and water, and the volume ratio of methanol to water is controlled at (4-6):

1.

4. The high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial according to claim 1, characterized in that The reaction temperature of the closed hydrothermal reaction in step (2) is 180° C., and the reaction time is 24 h; the reaction temperature of the closed hydrothermal reaction in step (3) is 120° C., and the reaction time is 24 h.

5. The high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial according to claim 1, characterized in that: The polar solvent in step (3) is a mixed solvent of dimethylformamide (DMF) and water, and the volume ratio of DMF to water is controlled at (5-12):1; the molar ratio of the cobalt source cobalt chloride to the ligand o-aminoterephthalic acid is controlled at (3-6):

1.

6. The high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial according to claim 1, characterized in that The calcination atmosphere in step (4) is nitrogen or argon, the temperature is controlled at 500°C-800°C, and the calcination time is controlled at 5-10 hours.

7. The application of the high-performance cobalt-based oxygen evolution electrocatalytic nanomaterial according to claim 1 in the oxygen evolution reaction of water electrolysis, in a three-electrode test system, in a 1.0 M KOH electrolyte, the ultra-low overpotential of 10 mA / cm was achieved at 235 mV and 264 mV, respectively. 2 and 100mA / cm 2 overpotential; with a Tafel slope as low as 80mV / dec.

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