A bimetallic FeNi-MOF oxygen evolution electrocatalyst and preparation method thereof

Abstract

The present invention relates to a bimetallic FeNi-MOF oxygen evolution electrocatalyst and a preparation method thereof. The technical scheme is: according to the molar ratio of ferrous ion: nickel ion of 1: (0.25-4), ferrous salt and nickel salt are mixed to obtain mixture A; according to the concentration of 0.017-0.019 mol / L, mixture A is dissolved in a mixture of deionized water and ethylenediamine, and ultrasonic dispersion is performed under sealed conditions to obtain solution A. According to the molar ratio of 1: 1, tetrahydroxy-1,4-benzoquinone and mixture A are mixed to obtain mixture B; according to the concentration of 0.017-0.019 mol / L, mixture B is dissolved in deionized water, and ultrasonic dispersion is performed under sealed conditions to obtain solution B. According to the volume ratio of solution B: solution A of 1: (0.95-1.05), the ingredients are prepared, mixed, ultrasonic dispersion is performed under sealed conditions, 75-85°C is kept warm for 10-12h, solid-liquid separation is performed, and drying is performed to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst. The invention has simple process and low cost, and the prepared product has excellent catalytic performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of oxygen evolution electrocatalysts, and specifically relates to a bimetallic FeNi-MOF oxygen evolution electrocatalyst and a preparation method thereof. Background Art

[0002] The huge demand for fuel in modern society and the serious resource consumption and environmental problems caused by the burning of fossil fuels have urgently required the development of a new type of green, pollution-free and sustainable energy. Hydrogen energy has attracted much attention due to its advantages of high efficiency and environmental friendliness, and is currently a very promising energy source. Currently, the main method of hydrogen production is water electrolysis. The efficiency of water electrolysis is affected by the overpotential of the oxygen evolution reaction (OER) on the anode, and an efficient and stable catalyst is required to accelerate the reaction.

[0003] Currently, ruthenium dioxide (RuO 2 ) is a state-of-the-art OER catalyst with low overpotential and Tafel slope, especially with good catalytic performance in alkaline environment. However, its high cost and scarce natural resources hinder the possibility of industrial application. In contrast, metal organic frameworks (MOFs) have high specific surface area, adjustable pore size and customizable surface chemical properties to maximize electrocatalytic activity.

[0004] Researchers have prepared unique metal oxide / porous carbon materials by high-temperature pyrolysis. These MOF derivatives have strong OER performance in alkaline electrolytes. However, the high-temperature pyrolysis process often requires multiple steps to complete, and may destroy the structure of MOF derivatives and reduce active sites. MOFs prepared by solvothermal method can be directly used as OER electrocatalysts without additional pyrolysis treatment. In addition, compared with the commonly used organic ligand HHTP, under the same conditions, MOFs prepared by THQ have a higher density of metal active sites per unit volume. Existing research results show that metal ions coordinate with N / O units in organic ligands such as HITP / HHTP, showing effective electronic coupling, which can reduce the adsorption energy of intermediates and show excellent catalytic activity for OER. Compared with these triphenylene-based ligands, tetrahydroxybenzoquinone, as the smallest π-conjugated ligand, shows a higher density of redox active sites. Therefore, research and development of OER catalysts with high catalytic activity and simple preparation are of concern to those skilled in the art.

[0005] The patented technology of "Preparation of a bimetallic MOF-derived oxygen evolution electrocatalyst" (CN201910554862.1) involves mixing and stirring a ferrous salt solution, a nickel salt solution, L-glutamic acid and an organic ligand, and then drying and carbonizing the resulting product to obtain a bimetallic MOF-derived oxygen evolution electrocatalyst. Since the carbonization step of this method needs to be completed at 800°C under the protection of an inert gas, it will destroy the structure of the MOF derivative, reduce the density of active sites, and have a low catalytic activity.

[0006] Tao Yufeng et al. (Tao Yufeng, Chen Tong, Chen Tao. Synthesis and electrocatalytic performance of metal organic framework materials [J]. Metallurgy and Materials, 2021, 41(06): 9-10.) first mixed copper acetate monohydrate and HHTP in a glass vial, then added deionized water and N, N-dimethylformamide, sealed it and placed it in a forced air oven and heated to 85 degrees Celsius. After reacting for 24 hours, it was centrifuged and washed three times with deionized water as the solvent, and dried to obtain Cu-HHTP-MOF. Since this method uses a triphenylene-based ligand, compared with the smallest π-conjugated ligand tetrahydroxy-p-benzoquinone, the redox active site density is lower and the catalytic activity for OER is lower.

[0007] Wen Yizhi et al. (Wen Yizhi. Preparation of strained ruthenium@RuO2 core-shell nanospheres and their electrocatalytic oxygen evolution performance [D]. Tianjin: Tianjin University, 2019.) ultrasonically dispersed commercial ruthenium dioxide powder and ultrapure water at a ratio of 1 mg:1 mL under sealed conditions for 20 min, irradiated with nanosecond parallel pulse laser for 20 min, poured into a watch glass, transferred to a refrigerator for freezing, and freeze-dried in a vacuum freeze drying oven to obtain Ru@RuO 2 -L. Although the samples prepared by this method have good OER catalytic performance, due to the use of ruthenium dioxide precious metal oxide as the main raw material and the need for laser irradiation, the manufacturing cost is high and the degree of industrial application is low. Summary of the invention

[0008] The present invention aims to overcome the defects of the prior art and aims to provide a method for preparing a bimetallic FeNi-MOF oxygen evolution electrocatalyst with simple process, low cost and easy industrial production. The bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared by the method has excellent catalytic performance.

[0009] To achieve the above object, the steps of the technical solution adopted by the present invention are:

[0010] Step 1: Mix ferrous salt and nickel salt at a molar ratio of ferrous ion to nickel ion of 1: (0.25-4) to obtain mixture A; then dissolve the mixture A in the mixed solution at a concentration of 0.017-0.019 mol / L, and ultrasonically disperse for 10-15 minutes under sealed conditions to obtain solution A.

[0011] The mixed solution is a mixture of deionized water and ethylenediamine, wherein the volume ratio of deionized water to ethylenediamine is 400-450:1.

[0012] Step 2: Mix the tetrahydroxy-1,4-benzoquinone and the mixture A at a molar ratio of 1:1 to obtain a mixture B; then dissolve the mixture B in deionized water at a concentration of 0.017 to 0.019 mol / L, and ultrasonically disperse for 50 to 60 minutes under sealed conditions to obtain a solution B.

[0013] Step 3: adding the solution B to the solution A at a volume ratio of the solution B to the solution A of 1: (0.95-1.05), ultrasonically dispersing for 10-15 min under sealed conditions, then keeping warm at 75-85° C. for 10-12 h, separating the solid and the liquid, and drying to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst.

[0014] The ferrous salt is one of ferrous sulfate and ferrous chloride; the purity of the ferrous salt is ≥99.8%.

[0015] The nickel salt is one of nickel acetate, nickel nitrate and nickel sulfate; the purity of the nickel salt is ≥99.95%.

[0016] The purity of the tetrahydroxy-1,4-benzoquinone is ≥95%.

[0017] Due to the adoption of the above technical solution, the present invention has the following positive effects compared with the prior art:

[0018] The present invention uses THQ as an organic ligand, ferrous iron and nickel as doped metal ions, and can prepare a bimetallic FeNi-MOF electrocatalyst through a simple solvothermal method without pyrolysis treatment, and the synthesis process is simple and the cost is low.

[0019] The MOF prepared by the solvothermal method of the present invention can be directly used as an OER electrocatalyst without the need for additional pyrolysis treatment. At the same time, the reaction temperature is low, the structure of the MOF derivative will not be destroyed, and the prepared MOF has a higher density of metal active sites per unit volume, and therefore has a higher catalytic activity.

[0020] The ligand used in the present invention is THQ. Compared with the commonly used organic ligand HHTP, under the same conditions, the MOF prepared by THQ has a higher density of metal active sites per unit volume. Existing research results show that metal ions coordinate with N / O units in organic ligands such as HITP / HHTP, showing effective electronic coupling, which can reduce the adsorption energy of intermediates and show excellent catalytic activity for OER. Compared with triphenylene-based HITP / HHTP, tetrahydroxy-p-benzoquinone, as the smallest π-conjugated ligand, shows a higher density of redox active sites.

[0021] The raw materials required by the present invention are relatively ruthenium dioxide (RuO 2 ) is low in cost and has abundant reserves on the earth, which can reduce the cost of hydrogen production and is suitable for industrial production.

[0022] Therefore, the present invention has the characteristics of simple process, low cost and easy industrial production, and the prepared bimetallic FeNi-MOF oxygen evolution catalyst has excellent catalytic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an LSV diagram of a bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in the present invention;

[0024] Figure 2 for Figure 1 Tafel slope plot of the bimetallic FeNi-MOF oxygen evolution electrocatalyst shown;

[0025] Figure 3 for Figure 1 TOF values ​​and mass activity diagram of the bimetallic FeNi-MOF oxygen evolution electrocatalyst shown. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods, which does not limit the protection scope of the present invention.

[0027] A method for preparing a bimetallic FeNi-MOF oxygen evolution electrocatalyst. The steps of the preparation method described in this specific embodiment are:

[0028] Step 1: Mix ferrous salt and nickel salt at a molar ratio of ferrous ion to nickel ion of 1: (0.25-4) to obtain mixture A; then dissolve the mixture A in the mixed solution at a concentration of 0.017-0.019 mol / L, and ultrasonically disperse for 10-15 minutes under sealed conditions to obtain solution A.

[0029] The mixed solution is a mixture of deionized water and ethylenediamine; in the mixed solution, the volume ratio of deionized water to ethylenediamine is 400-450:1.

[0030] Step 2: Mix the tetrahydroxy-1,4-benzoquinone and the mixture A at a molar ratio of 1:1 to obtain a mixture B; then dissolve the mixture B in deionized water at a concentration of 0.017 to 0.019 mol / L, and ultrasonically disperse for 50 to 60 minutes under sealed conditions to obtain a solution B.

[0031] Step 3: adding the solution B to the solution A at a volume ratio of the solution B to the solution A of 1: (0.95-1.05), ultrasonically dispersing for 10-15 min under sealed conditions, then keeping warm at 75-85° C. for 10-12 h, separating the solid and the liquid, and drying to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst.

[0032] The ferrous salt is one of ferrous sulfate and ferrous chloride.

[0033] The nickel salt is one of nickel acetate, nickel nitrate and nickel sulfate.

[0034] In this specific implementation mode:

[0035] The purity of the ferrous salt is ≥99.8%;

[0036] The purity of the nickel salt is ≥99.95%;

[0037] The purity of the tetrahydroxy-1,4-benzoquinone is ≥95%.

[0038] The Fe of the bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in this specific embodiment y Ni 4-y C x The electrochemical performance test method is:

[0039] Take 40 mg of the bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in each corresponding embodiment of this specific embodiment, 10 mg of carbon black, 7000 μL of ethanol and 500 μL of Nafion, mix, and ultrasonically treat for 30 minutes to obtain a slurry; then take 16 μL of the slurry and add it dropwise to the surface of the glassy carbon electrode as a working electrode, and dry it at room temperature; then use a platinum sheet and an Ag / AgCl electrode as the corresponding counter electrode and reference electrode.

[0040] The test electrolyte is 100ml of 1mol / L KOH solution; the test conditions are normal temperature and pressure; the test equipment is CHI660E electrochemical workstation. The polarization curve test voltage is 0V~0.8V; the scan rate is 5mVs -1 .

[0041] This will not be described in detail in the embodiments.

[0042] Example 1

[0043] A bimetallic FeNi-MOF oxygen evolution electrocatalyst and a preparation method thereof. The steps of the preparation method are:

[0044] Step 1: Mix ferrous salt and nickel salt at a molar ratio of ferrous ion to nickel ion of 1:0.25 to obtain mixture A; then dissolve the mixture A in the mixed solution at a concentration of 0.017 mol / L, and ultrasonically disperse for 10 minutes under sealed conditions to obtain solution A.

[0045] The mixed solution is a mixture of deionized water and ethylenediamine, and the volume ratio of deionized water to ethylenediamine in the mixed solution is 400:1.

[0046] Step 2: Mix the tetrahydroxy-1,4-benzoquinone and the mixture A at a molar ratio of 1:1 to obtain a mixture B; then dissolve the mixture B in deionized water at a concentration of 0.017 mol / L, and ultrasonically disperse for 50 minutes under sealed conditions to obtain a solution B.

[0047] Step 3: adding the solution B to the solution A at a volume ratio of 1:0.95, ultrasonically dispersing for 10 minutes under sealed conditions, then keeping warm at 75° C. for 10 hours, separating the solid and the liquid, and drying to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst.

[0048] The ferrous salt is ferrous sulfate.

[0049] The nickel salt is nickel acetate.

[0050] The Fe of the bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in this example y Ni 4-y C x Electrochemical performance test: overpotential is 300mV.

[0051] Example 2

[0052] A bimetallic FeNi-MOF oxygen evolution electrocatalyst and a preparation method thereof. The steps of the preparation method are:

[0053] Step 1: Mix ferrous salt and nickel salt at a molar ratio of ferrous ion to nickel ion of 1:0.67 to obtain mixture A; then dissolve the mixture A in the mixed solution at a concentration of 0.017 mol / L, and ultrasonically disperse for 10 minutes under sealed conditions to obtain solution A.

[0054] The mixed solution is a mixture of deionized water and ethylenediamine, and the volume ratio of deionized water to ethylenediamine in the mixed solution is 4:10:1.

[0055] Step 2: Mix the tetrahydroxy-1,4-benzoquinone and the mixture A at a molar ratio of 1:1 to obtain a mixture B; then dissolve the mixture B in deionized water at a concentration of 0.0175 mol / L, and ultrasonically disperse for 52 minutes under sealed conditions to obtain a solution B.

[0056] Step 3: adding the solution B to the solution A at a volume ratio of the solution B to the solution A of 1:0.95, ultrasonically dispersing for 12 minutes under sealed conditions, then keeping warm at 78° C. for 10.5 hours, separating the solid and the liquid, and drying to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst.

[0057] The ferrous salt is ferrous chloride.

[0058] The nickel salt is nickel nitrate.

[0059] The Fe of the bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in this example y Ni 4-y C x Electrochemical performance test: overpotential is 282mV.

[0060] Example 3

[0061] A bimetallic FeNi-MOF oxygen evolution electrocatalyst and a preparation method thereof. The steps of the preparation method are:

[0062] Step 1: Mix ferrous salt and nickel salt at a molar ratio of ferrous ion to nickel ion of 1:1 to obtain mixture A; then dissolve the mixture A in the mixed solution at a concentration of 0.018 mol / L, and ultrasonically disperse for 15 minutes under sealed conditions to obtain solution A.

[0063] The mixed solution is a mixture of deionized water and ethylenediamine, and the volume ratio of deionized water to ethylenediamine in the mixed solution is 420:1.

[0064] Step 2: Mix the tetrahydroxy-1,4-benzoquinone and the mixture A at a molar ratio of 1:1 to obtain a mixture B; then dissolve the mixture B in deionized water at a concentration of 0.018 mol / L, and ultrasonically disperse for 54 minutes under sealed conditions to obtain a solution B.

[0065] Step 3: adding the solution B to the solution A at a volume ratio of 1:1, ultrasonically dispersing for 13 minutes under sealed conditions, then keeping warm at 80° C. for 11 hours, separating the solid and the liquid, and drying to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst.

[0066] The ferrous salt is ferrous sulfate.

[0067] The nickel salt is nickel sulfate.

[0068] The Fe of the bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in this example y Ni 4-y C x Electrochemical performance test: overpotential is 272mV.

[0069] Example 4

[0070] A bimetallic FeNi-MOF oxygen evolution electrocatalyst and a preparation method thereof. The steps of the preparation method are:

[0071] Step 1: Mix ferrous salt and nickel salt at a molar ratio of ferrous ion to nickel ion of 1:1.5 to obtain mixture A; then dissolve the mixture A in the mixed solution at a concentration of 0.019 mol / L, and ultrasonically disperse for 15 minutes under sealed conditions to obtain solution A.

[0072] The mixed solution is a mixture of deionized water and ethylenediamine, and the volume ratio of deionized water to ethylenediamine in the mixed solution is 430:1.

[0073] Step 2: Mix the tetrahydroxy-1,4-benzoquinone and the mixture A at a molar ratio of 1:1 to obtain a mixture B; then dissolve the mixture B in deionized water at a concentration of 0.0185 mol / L, and ultrasonically disperse for 56 minutes under sealed conditions to obtain a solution B.

[0074] Step 3: adding the solution B to the solution A at a volume ratio of 1:1.05, ultrasonically dispersing for 14 minutes under sealed conditions, then keeping warm at 82° C. for 11.5 hours, separating the solid and the liquid, and drying to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst.

[0075] The ferrous salt is ferrous chloride.

[0076] The nickel salt is nickel acetate.

[0077] The Fe of the bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in this example y Ni 4-y Cx Electrochemical performance test: overpotential is 380mV.

[0078] Example 5

[0079] A bimetallic FeNi-MOF oxygen evolution electrocatalyst and a preparation method thereof. The steps of the preparation method are:

[0080] Step 1: Mix ferrous salt and nickel salt at a molar ratio of ferrous ion to nickel ion of 1:4 to obtain mixture A; then dissolve the mixture A in the mixed solution at a concentration of 0.019 mol / L, and ultrasonically disperse for 15 minutes under sealed conditions to obtain solution A.

[0081] The mixed solution is a mixture of deionized water and ethylenediamine, and the volume ratio of deionized water to ethylenediamine in the mixed solution is 450:1.

[0082] Step 2: Mix the tetrahydroxy-1,4-benzoquinone and the mixture A at a molar ratio of 1:1 to obtain a mixture B; then dissolve the mixture B in deionized water at a concentration of 0.019 mol / L, and ultrasonically disperse for 60 minutes under sealed conditions to obtain a solution B.

[0083] Step 3: adding the solution B to the solution A at a volume ratio of 1:1.05, ultrasonically dispersing for 15 minutes under sealed conditions, then keeping warm at 85°C for 12 hours, separating the solid and the liquid, and drying to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst.

[0084] The ferrous salt is ferrous chloride.

[0085] The nickel salt is nickel nitrate.

[0086] The Fe of the bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in this example y Ni 4-y C x Electrochemical performance test: overpotential is 414mV.

[0087] Compared with the prior art, this specific implementation has the following positive effects:

[0088] In this specific embodiment, THQ is used as an organic ligand, and ferrous iron and nickel are used as doped metal ions. A bimetallic FeNi-MOF electrocatalyst can be prepared by a simple solvothermal method without pyrolysis treatment, and a one-step reaction is required. The synthesis process is simple and the cost is low.

[0089] The MOF prepared by the solvothermal method in this embodiment can be directly used as an OER electrocatalyst without the need for additional pyrolysis treatment. At the same time, the reaction temperature is low and the structure of the MOF derivative will not be destroyed. The prepared MOF has a higher density of metal active sites per unit volume, and therefore has a higher catalytic activity.

[0090] The ligand used in this specific embodiment is THQ. Compared with the commonly used organic ligand HHTP, under the same conditions, the MOF prepared by THQ has a higher density of metal active sites per unit volume. Existing research results show that metal ions coordinate with N / O units in organic ligands such as HITP / HHTP, showing effective electronic coupling, which can reduce the adsorption energy of intermediates and show excellent catalytic activity for OER. Compared with triphenylene-based HITP / HHTP, tetrahydroxybenzoquinone, as the smallest π-conjugated ligand, shows a higher density of redox active sites.

[0091] The bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in this specific embodiment is shown in the accompanying drawings. Figure 1 LSV diagram of the bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared in Example 3; Figure 2 for Figure 1 Tafel slope plot of the bimetallic FeNi-MOF oxygen evolution electrocatalyst shown; Figure 3 for Figure 1 TOF values ​​and mass activity diagram of the bimetallic FeNi-MOF oxygen evolution electrocatalyst shown.

[0092] from Figure 1 It can be seen that when the current density of the prepared bimetallic FeNi-MOF oxygen evolution electrocatalyst reaches 10 mA cm -1 The required overpotential is only 1.501 V (vsRHE relative to the reversible hydrogen electrode), so the prepared bimetallic FeNi-MOF oxygen evolution electrocatalyst has good OER performance.

[0093] from Figure 2 It can be seen that the Tafel slope of the bimetallic FeNi-MOF oxygen evolution electrocatalyst is 47.9 mVdec-1, indicating that the bimetallic FeNi-MOF oxygen evolution electrocatalyst has excellent catalytic kinetics.

[0094] from Figure 3 It can be seen that the mass specific activity value of the bimetallic FeNi-MOF is 36.93 mV per mg, indicating that the bimetallic FeNi-MOF oxygen evolution electrocatalyst has many catalytic active sites. The TOF value of the bimetallic FeNi-MOF is 0.048 s-1, indicating that the bimetallic FeNi-MOF oxygen evolution electrocatalyst has high intrinsic electrocatalytic activity.

[0095] The raw materials required for this specific embodiment are relatively large compared to ruthenium dioxide (RuO 2 ) is low in cost and abundant in earth reserves, which can reduce the cost of bimetallic FeNi-MOF oxygen evolution electrocatalyst and is suitable for industrial production.

[0096] Therefore, this specific embodiment has the characteristics of simple process, low cost and easy industrial production, and the prepared bimetallic FeNi-MOF oxygen evolution catalyst has excellent catalytic performance.

Claims

1. A method for preparing a bimetallic FeNi-MOF oxygen evolution electrocatalyst, characterized in that The steps of the preparation method are: Step 1, mixing ferrous salt and nickel salt at a molar ratio of ferrous ion to nickel ion of 1: (0.25-4) to obtain a mixture A; then dissolving the mixture A in a mixed solution at a concentration of 0.017-0.019 mol / L, and ultrasonically dispersing for 10-15 min under a sealed condition to obtain a solution A; The mixed solution is a mixture of deionized water and ethylenediamine, wherein the volume ratio of deionized water to ethylenediamine is 400-450:1; The ferrous salt is one of ferrous sulfate and ferrous chloride; the purity of the ferrous salt is ≥99.8%; The nickel salt is one of nickel acetate, nickel nitrate and nickel sulfate; the purity of the nickel salt is ≥99.95%; Step 2, the tetrahydroxy-1,4-benzoquinone and the mixture A are mixed at a molar ratio of 1:1 to obtain a mixture B; then the mixture B is dissolved in deionized water at a concentration of 0.017 to 0.019 mol / L, and ultrasonically dispersed for 50 to 60 minutes under sealed conditions to obtain a solution B; The purity of the tetrahydroxy-1,4-benzoquinone is ≥95%; Step 3: adding the solution B to the solution A at a volume ratio of the solution B to the solution A of 1: (0.95-1.05), ultrasonically dispersing for 10-15 min under sealed conditions, then keeping warm at 75-85° C. for 10-12 h, separating the solid and the liquid, and drying to obtain a bimetallic FeNi-MOF oxygen evolution electrocatalyst.

2. A bimetallic FeNi-MOF oxygen evolution electrocatalyst, characterized in that The bimetallic FeNi-MOF oxygen evolution electrocatalyst is a bimetallic FeNi-MOF oxygen evolution electrocatalyst prepared according to the preparation method of the bimetallic FeNi-MOF oxygen evolution electrocatalyst according to claim 1.

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