Oxygen-containing anion modified oxygen evolution electrode for AEMWE and preparation method of oxygen-containing anion modified oxygen evolution electrode

Abstract

The invention aims at providing an oxygen-containing anion modified oxygen evolution electrode for AEMWE and a preparation method of the oxygen-containing anion modified oxygen evolution electrode, and belongs to the technical field of hydrogen production through electrolysis of water. Introducing a second cation and an oxygen-containing anion through dipping treatment; and finally, carrying out cyclic voltammetry electrochemical activation treatment to obtain the oxygen evolution electrode modified by the oxygen-containing anion. The invention provides an AEMWE anode gas diffusion electrode preparation route which is rapid, controllable, simple in method and relatively mild in synthesis condition, the oxygen evolution electrode prepared by the method has high activity and long-term durability under ampere-level current density, and has low cell pressure and long-term stability under AEMWE industrial conditions; the catalyst cost and the hydrogen production energy consumption are effectively reduced. The preparation method is suitable for cheap iron-based metal materials, different oxygen-containing anions can be introduced, and the preparation method has huge potential application value and wide application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by electrolyzing water, and particularly relates to an oxygen-containing anion modified oxygen evolution electrode for AEMWE and a preparation method thereof. Background Art

[0002] Hydrogen production by electrolyzing water can utilize intermittent renewable electric energies such as solar energy and wind energy to produce "green hydrogen", which is a sustainable and scalable technology. At present, the mature technologies for converting renewable energy into hydrogen include alkaline water electrolysis (AWE) technology and proton exchange membrane water electrolysis (PEMWE) technology. Compared with AWE, PEMWE has inherent advantages such as higher H2 purity, higher current density, less gas crossover, and faster start-up time. However, due to the acidic operating environment of PEMWE, it requires a large amount of platinum group metal materials as electrocatalysts. Especially in the slow oxygen evolution reaction (OER) at the anode, expensive IrO x catalyst with a high loading (>2 mg Ir cm -2 −2) results in a high cost of green H2 (about $6 / kg H2). Anion exchange membrane water electrolysis (AEMWE) as an emerging energy conversion technology allows the use of cheaper non-platinum group metal catalysts, cheaper ion exchange membranes, does not contain environmentally harmful fluorine-based polymers, and does not require acid-resistant stack materials, thus reducing the overall equipment cost.

[0003] However, AEMWE technology is a relatively new technology and faces many problems before its full potential can be realized. The catalyst is a key factor. Developing high-performance non-precious metal anode OER electrocatalysts faces two main challenges. One is that the current synthesis methods of these catalysts have not been optimized to be suitable for industrial applications. Therefore, in practical situations, simple and feasible synthesis methods that can produce a large amount of catalysts must be considered. The other is that although iron-based metal (Fe, Co, Ni) materials have been widely studied as OER catalysts, their stability is poor under the compact AEMWE working conditions (higher temperature, higher current density, and more complex electrode structure). Therefore, developing electrocatalysts that are easy to manufacture, inexpensive, and have efficient and stable OER performance at ampere-level current density is the key to promoting the industrialization of AEMWE. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art and the requirements of research and application in this field, the object of the present invention is to provide an oxygen-containing anion modified oxygen evolution electrode for AEMWE and a preparation method thereof.

[0005] The present invention adopts the following technical solutions: An oxygen anion-modified oxygen evolution electrode for AEMWE, the oxygen anion-modified oxygen evolution electrode uses a porous conductive material as a substrate, introduces oxygen-containing boron anions through rapid alternating impregnation, then introduces a second cation and an oxygen anion through impregnation treatment, and finally obtains the oxygen anion-modified oxygen evolution electrode through cyclic voltammetry electrochemical activation treatment.

[0006] A preparation method of an oxygen anion-modified oxygen evolution electrode for AEMWE, comprising the following steps: S1. Alternately impregnate the treated porous conductive substrate in a solution containing a transition metal source and a solution containing a boron source for several times, take it out and dry it at 80 °C for 1-2 h, wash it several times with deionized water and ethanol, and then dry it in vacuum to obtain Electrode 1; S2. Immerse Electrode 1 obtained in S1 in a mixed solution containing an iron source and different anions or alternately impregnate it in a solution containing iron ions and a solution containing different anions for several times, take it out and dry it at 80 °C for 1-2 h, wash it several times with deionized water and ethanol, and then dry it in vacuum to obtain Electrode 2; S3. Perform cyclic voltammetry treatment on Electrode 2 obtained in S2 in a potassium hydroxide solution to obtain an oxygen anion-modified oxygen evolution electrode.

[0007] Further, the porous conductive substrate in S1 includes any one of nickel foam, iron foam, cobalt foam, copper foam, nickel-iron foam or cobalt-iron foam.

[0008] Further, the treatment method of the porous conductive substrate in S1 is as follows: ultrasonically treat it with acetone, hydrochloric acid, deionized water and ethanol for 20 min respectively to remove impurities on the surface of the porous conductive substrate, and then dry it at 80 °C.

[0009] Further, the transition metal source in S1 includes any soluble nickel salt or cobalt salt.

[0010] Further, the concentration of the solution containing the transition metal source in S1 is 0.05-0.5 mol / L.

[0011] Further, the boron source in S1 is sodium borohydride, and sodium borohydride is a strong reducing agent that can quickly reduce transition metal ions to obtain borides, and then obtain oxygen-containing boron anion compounds through oxidation and drying in air.

[0012] Further, the molar ratio of the transition metal to sodium borohydride in S1 is 1:3.

[0013] Further, the iron source in S2 includes any soluble iron salt.

[0014] Further, the concentration of the solution containing iron ions in S2 is 0.05-0.5 mol / L.

[0015] Further, the anions described in S2 include selenous acid, potassium dihydrogen phosphate, or sodium thiosulfate.

[0016] Further, the concentration of the potassium hydroxide solution described in S3 is 1 - 6 mol / L.

[0017] Further, the range of the cyclic voltammetry scan described in S3 is 0.1 - 1.9 V (V vs. Hg / HgO).

[0018] Further, the number of cycles of the cyclic voltammetry scan described in S3 is ≥20.

[0019] In addition, the oxygen - containing anion - modified oxygen - evolution electrode of the present invention is applied to the anodic oxygen - evolution reaction of AEMWE.

[0020] The principle of the present invention is as follows: The porous conductive substrate not only serves as a reaction substrate but also provides a metal source to enhance the attachment of the catalyst. Sodium borohydride is a strong reducing agent that can quickly reduce nickel / cobalt ions to metallic nickel / cobalt. Excess sodium borohydride further reacts with metallic nickel / cobalt to form nickel / cobalt boride compounds, and then through air oxidation and drying, oxygen - containing boron - anion compounds are obtained. Selenous acid, potassium dihydrogen phosphate, and sodium thiosulfate can form complexes with ferric ions, and then through air oxidation and drying, iron - based compounds containing different anions are obtained. Finally, during the electrochemical treatment in potassium hydroxide, oxygen - containing boron anions are leached out and adsorbed on the surface, part of the oxygen - containing selenium / phosphorus / sulfur anions are leached out, and metal ions migrate accordingly and react with OH - to form hydroxyoxides, and finally, an oxygen - containing anion - modified oxygen - evolution electrode is re - constructed.

[0021] The present invention provides a preparation route for the anodic gas - diffusion electrode of AEMWE that is fast - controllable, simple in method, and relatively mild in synthesis conditions. The oxygen - evolution electrode prepared by this invention has high activity and long - term durability at ampere - level current density, and has low cell voltage and long - term stability under AEMWE industrial conditions, effectively reducing the catalyst cost and hydrogen - production energy consumption.

[0022] Compared with the prior art, the present invention has the following main advantages and beneficial effects: 1. Compared with noble metal (Ru / Ir) materials, the oxygen - evolution electrode of the present invention has a significant price advantage, and the raw materials are widely available. Moreover, the preparation method is a simple impregnation method, with simple process, convenient operation, and easy for large - scale production, greatly reducing the cost and environmental pollution of traditional preparation methods. In addition, by using this preparation method, an integrated self - supporting electrode can be obtained without using non - conductive binders, which is conducive to realizing economic and large - scale electrode preparation.

[0023] 2. The oxygen anion-modified oxygen evolution electrode of the present invention has excellent oxygen evolution catalytic performance. The modification of oxygen anions greatly improves the intrinsic activity and stability of the catalytic electrode, enabling it to exhibit a low cell voltage and drive an oxygen evolution reaction with an amperometric current density stably for a long time under the industrial conditions of AEMWE.

[0024] The present invention is reasonably designed. The preparation method is applicable to inexpensive iron-based metal (Fe, Co, Ni) materials and can introduce different oxygen anions, having great potential application value and broad application prospects. Description of the Drawings

[0025] Figure 1 Scanning electron microscope image of Ni / NiFe(Se)OH-BO obtained in Example 1.

[0026] Figure 2 Raman spectrum of Ni / NiFe(Se)OH-BO obtained in Example 1.

[0027] Figure 3 X-ray diffraction spectrum of Ni / NiFe(Se)OH-BO obtained in Example 1.

[0028] Figure 4 X-ray photoelectron spectrum of Ni / NiFe(Se)OH-BO obtained in Example 1.

[0029] Figure 5 Linear sweep voltammetry curve for oxygen evolution performance test of Ni / NiFe(Se)OH-BO obtained in Example 1 (1 mol / L potassium hydroxide).

[0030] Figure 6 Stability test curve of Ni / NiFe(Se)OH-BO obtained in Example 1.

[0031] Figure 7 Linear sweep voltammetry curve of Ni / NiFe(Se)OH-BO obtained in Example 1 in AEMWE.

[0032] Figure 8 Stability test curve of Ni / NiFe(Se)OH-BO obtained in Example 1 in AEMWE.

[0033] Figure 9 Linear sweep voltammetry curve for oxygen evolution performance test of NiFe / NiFe(Se)OH-BO obtained in Example 2 (1 mol / L potassium hydroxide).

[0034] Figure 10Shows the linear voltammogram of the oxygen evolution performance test of Cu / NiFe(Se)OH-BO obtained in Example 3 (1 mol / L potassium hydroxide).

[0035] Figure 11 Shows the linear voltammogram of the oxygen evolution performance test of Ni / CoFe(Se)OH-BO obtained in Example 4 (1 mol / L potassium hydroxide).

[0036] Figure 12 Shows the linear voltammogram of the oxygen evolution performance test of Ni / NiFe(P)OH-BO obtained in Example 5 (1 mol / L potassium hydroxide).

[0037] Figure 13 Shows the linear voltammogram of the oxygen evolution performance test of Ni / NiFe(S)OH-BO obtained in Example 6 (1 mol / L potassium hydroxide). Detailed implementation manners

[0038] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following, in conjunction with the accompanying drawings, details the specific embodiments of the present invention, but is not limited thereto. Unless otherwise specified, the raw materials used in the examples are all ordinary commercially available products; unless otherwise specified, the methods used are all common methods in the art.

[0039] Example 1 A preparation method of an oxygen-containing anion modified oxygen evolution electrode for AEMWE, comprising the following steps: (1) Alternately immerse the treated nickel foam in 15 mL of a nickel chloride solution containing 0.5 mol / L and 15 mL of a sodium borohydride solution containing 1.5 mol / L for 10 s each, repeat 4 times, take out and dry at 80 °C for 1 - 2 h, wash several times with deionized water and ethanol, and then dry in vacuum; (2) Alternately immerse the electrode obtained in step (1) in 15 mL of an iron chloride solution containing 0.1 mol / L and 15 mL of a selenious acid solution containing 0.1 mol / L for 10 s each, repeat 3 times, take out and dry at 80 °C for 1 - 2 h, wash several times with deionized water and ethanol, and then dry in vacuum; (3) Perform 20 cycles of cyclic voltammetry treatment on the electrode obtained in step (2) in a 1 mol / L potassium hydroxide solution, with a voltage range of 0.1 - 1.9 V (V vs. Hg / HgO), to obtain an oxygen evolution electrode modified with oxygen-containing boron anions and oxygen-containing selenium anions (denoted as Ni / NiFe(Se)OH-BO).

[0040] The scanning electron microscope photograph of the Ni / NiFe(Se)OH-BO oxygen evolution electrode prepared in this Example 1 is as Figure 1 shown, from Figure 1It can be seen that the prepared Ni / NiFe(Se)OH-BO oxygen evolution electrode has a structure of ultrathin nanosheets, which is beneficial to the rapid mass / electron transfer at high current densities.

[0041] The Raman spectrum of the Ni / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 1 is as Figure 2 shown. It can be seen from Figure 2 that the peaks at 475 cm -1 and 553 cm -1 correspond to the vibration of the Ni-O bond in NiOOH, and the peaks at 314 cm -1 and 678 cm -1 correspond to the vibration of the Fe-O bond in FeOOH, indicating that the active phase of the oxygen evolution electrode obtained by this preparation method is NiFeOOH.

[0042] The X-ray diffraction spectrum of the Ni / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 1 is as Figure 3 shown. It can be seen from Figure 3 that the characteristic peaks of Ni / NiFe(Se)OH-BO correspond to those of NiFe LDH (PDF#40-0215), and some characteristic peaks are positively shifted due to the presence of high-valent Ni, indicating that the oxygen evolution electrode obtained by this preparation method has a structure similar to that of NiFe LDH.

[0043] The X-ray photoelectron spectrum of the Ni / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 1 is as Figure 4 shown. It can be seen from Figure 4 that Ni and Fe exist in the forms of Ni 3+ and Fe 3+ , and the B 1s and Se 3d spectra indicate the introduction of oxygen-containing boron anions and oxygen-containing selenium anions.

[0044] The oxygen evolution performance of the obtained electrode was tested by a three-electrode system to obtain the polarization curve. Using 1 mol / L potassium hydroxide as the electrolyte, the obtained electrode as the working electrode, the Hg / HgO (1 mol / L potassium hydroxide) electrode as the reference electrode, and the carbon rod as the counter electrode. The polarization curve test window was 0~2 V (vs RHE), and the scanning rate was 2 mV / s. The oxygen evolution performance test curve of the Ni / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 1 is as Figure 5 shown. It can be seen from Figure 5 that the prepared Ni / NiFe(Se)OH-BO oxygen evolution electrode only needs 216 mV and 282 mV to drive current densities of 0.1 A / cm 2 and 1 A / cm 2 .

[0045] The stability of the obtained electrode was tested by chronopotentiometry in a three-electrode system. Using 1 mol / L potassium hydroxide as the electrolyte, the obtained electrode as the working electrode, a Hg / HgO (1 mol / L potassium hydroxide) electrode as the reference electrode, and a carbon rod as the counter electrode. The chronopotentiometry test selected a current density of 1 A / cm 2 . The stability test curve of the Ni / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 1 at 1 A / cm 2 is as shown in Figure 6 . As can be seen from Figure 6 , the prepared oxygen evolution electrode can stably drive the oxygen evolution reaction at a large current density for a long time.

[0046] The performance of the obtained electrode in the AEMWE was tested by obtaining the polarization curve through assembling the AEMWE with a coupled Pt / C hydrogen evolution electrode. The working geometric area of the AEMWE was 1 cm 2 . The obtained electrode (thickness: 0.4 mm), Pt / C electrode (loading: 0.4 mg Pt / cm 2 ) and the anion exchange membrane (Sustainion X37-50) were "sandwiched" together to assemble the AEMWE. 1 mol / L potassium hydroxide at 70 °C flowed through the AEMWE at a flow rate of 50 mL / min. The polarization curve test window was 1 - 2.1 V, and the scan rate was 5 mV / s. The performance test curve of the Ni / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 1 in the AEMWE is as shown in Figure 7 . As can be seen from Figure 7 , the prepared Ni / NiFe(Se)OH-BO oxygen evolution electrode coupled with the Pt / C hydrogen evolution electrode only requires 1.69 V to drive a current density of 1 A / cm 2 , and when the cell voltage is 2 V, the current density is as high as 2.8 A / cm 2 .

[0047] The stability of the obtained electrode coupled with the Pt / C hydrogen evolution electrode in the AEMWE was obtained through chronopotentiometry. The working geometric area of the AEMWE was 1 cm 2 . The obtained electrode (thickness: 0.4 mm), Pt / C electrode (loading: 0.4 mg Pt / cm 2 ) and the anion exchange membrane (Sustainion X37-50) were "sandwiched" together to assemble the AEMWE. 1 mol / L potassium hydroxide at 70 °C flowed through the AEMWE at a flow rate of 50 mL / min. The chronopotentiometry test selected a current density of 1 A / cm 2。The stability test curve of the Ni / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 1 coupled with the Pt / C hydrogen evolution electrode in the AEMWE is as Figure 8 shown. It can be seen from Figure 8 that the prepared Ni / NiFe(Se)OH-BO oxygen evolution electrode coupled with the Pt / C hydrogen evolution electrode can stably drive an AEMWE with an amperometric large current density for a long time.

[0048] Example 2 A preparation method of an oxygen anion modified oxygen evolution electrode for AEMWE, comprising the following steps: (1) Alternately immerse the treated nickel foam iron in 15 mL of a nickel chloride solution containing 0.5 mol / L and 15 mL of a sodium borohydride solution containing 1.5 mol / L for 10 s each time, repeat 4 times, take it out and dry it at 80 °C for 1-2 h, wash it several times with deionized water and ethanol, and then dry it in vacuum; (2) Alternately immerse the electrode obtained in step (1) in 15 mL of an iron chloride solution containing 0.1 mol / L and 15 mL of a selenious acid solution containing 0.1 mol / L for 10 s each time, repeat 3 times, take it out and dry it at 80 °C for 1-2 h, wash it several times with deionized water and ethanol, and then dry it in vacuum; (3) Perform 20 cycles of cyclic voltammetry treatment on the electrode obtained in step (2) in 1 mol / L potassium hydroxide solution, and its voltage range is 0.1-1.9 V (V vs. Hg / HgO) to obtain an oxygen evolution electrode modified with oxygen-containing boron anions and oxygen-containing selenium anions (denoted as NiFe / NiFe(Se)OH-BO).

[0049] The oxygen evolution performance test curve of the NiFe / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 2 is as Figure 9 shown. It can be seen from Figure 9 that the prepared NiFe / NiFe(Se)OH-BO oxygen evolution electrode only needs 216 mV and 295 mV to drive 0.1 A / cm 2 and 1 A / cm 2 of current density.

[0050] Example 3 A preparation method of an oxygen anion modified oxygen evolution electrode for AEMWE, comprising the following steps: (1) Alternately immerse the treated copper foam in 15 mL of a nickel chloride solution containing 0.5 mol / L and 15 mL of a sodium borohydride solution containing 1.5 mol / L for 10 s each time, repeat 4 times, take it out and dry it at 80 °C for 1-2 h, wash it several times with deionized water and ethanol, and then dry it in vacuum; (2) The electrode obtained in step (1) was alternately immersed in 15 mL of a solution containing 0.1 mol / L ferric chloride and 15 mL of a solution containing 0.1 mol / L selenious acid, each immersion for 10 s, repeated 3 times. After taking out, it was dried at 80 °C for 1 - 2 h, washed several times with deionized water and ethanol, and then dried in vacuum; (3) The electrode obtained in step (2) was subjected to 20 cycles of cyclic voltammetry in 1 mol / L potassium hydroxide solution, and the voltage range was 0.1 - 1.9 V (V vs. Hg / HgO), to obtain an oxygen evolution electrode modified with oxygen-containing borate anions and oxygen-containing selenite anions (denoted as Cu / NiFe(Se)OH-BO).

[0051] The oxygen evolution performance test curve of the Cu / NiFe(Se)OH-BO oxygen evolution electrode prepared in Example 3 is as Figure 10 shown, and it can be seen from Figure 10 that the prepared Cu / NiFe(Se)OH-BO oxygen evolution electrode only needs 263 mV and 358 mV to drive a current density of 0.1 A / cm 2 and 1 A / cm 2 .

[0052] Example 4 A preparation method of an oxygen-containing anion modified oxygen evolution electrode for AEMWE, comprising the following steps: (1) The treated nickel foam was alternately immersed in 15 mL of a solution containing 0.5 mol / L cobalt chloride and 15 mL of a solution containing 1.5 mol / L sodium borohydride, each immersion for 10 s, repeated 4 times. After taking out, it was dried at 80 °C for 1 - 2 h, washed several times with deionized water and ethanol, and then dried in vacuum; (2) The electrode obtained in step (1) was alternately immersed in 15 mL of a solution containing 0.1 mol / L ferric chloride and 15 mL of a solution containing 0.1 mol / L selenious acid, each immersion for 10 s, repeated 7 times. After taking out, it was dried at 80 °C for 1 - 2 h, washed several times with deionized water and ethanol, and then dried in vacuum; (3) The electrode obtained in step (2) was subjected to 20 cycles of cyclic voltammetry in 1 mol / L potassium hydroxide solution, and the voltage range was 0.1 - 1.9 V (V vs. Hg / HgO), to obtain an oxygen evolution electrode modified with oxygen-containing borate anions and oxygen-containing selenite anions (denoted as Ni / CoFe(Se)OH-BO).

[0053] The oxygen evolution performance test curve of the Ni / CoFe(Se)OH-BO oxygen evolution electrode prepared in Example 4 is as Figure 11 shown, and it can be seen from Figure 11 that the prepared Ni / CoFe(Se)OH-BO oxygen evolution electrode only needs 239 mV and 356 mV to drive a current density of 0.1 A / cm 2and 1A / cm 2 current density.

[0054] Example 5 A method for preparing an oxygen-evolving electrode modified with an oxygen-containing anion for AEMWE comprises the following steps: (1) The treated nickel foam was alternately immersed in 15 mL of 0.5 mol / L nickel chloride solution and 15 mL of 1.5 mol / L sodium borohydride solution for 10 s each, repeated 4 times, and then dried at 80 °C for 1-2 h. After washing with deionized water and ethanol several times, the foam was vacuum dried. (2) The electrode obtained in step (1) was alternately immersed in 15 mL of 0.1 mol / L ferric chloride solution and 15 mL of 0.1 mol / L potassium dihydrogen phosphate solution for 10 s each, and repeated 7 times. After removal, it was dried at 80°C for 1-2 h, washed several times with deionized water and ethanol, and then vacuum dried. (3) The electrode obtained in step (2) was subjected to 20 cycles of cyclic voltammetry in a 1 mol / L potassium hydroxide solution in a voltage range of 0.1 to 1.9 V (V vs. Hg / HgO), thereby obtaining an oxygen evolution electrode modified with oxygen-containing boron anions and oxygen-containing phosphorus anions (denoted as Ni / NiFe(P)OH-BO).

[0055] The oxygen evolution performance test curve of the Ni / NiFe(P)OH-BO oxygen evolution electrode prepared in Example 5 is as follows: Figure 12 As shown by Figure 12 It can be seen that the prepared Ni / NiFe(P)OH-BO oxygen evolution electrode only needs 232mV and 338mV to drive 0.1A / cm 2 and 1A / cm 2 current density.

[0056] Example 6 A method for preparing an oxygen-evolving electrode modified with an oxygen-containing anion for AEMWE comprises the following steps: (1) The treated nickel foam was alternately immersed in 15 mL of 0.5 mol / L nickel chloride solution and 15 mL of 1.5 mol / L sodium borohydride solution for 10 s each, repeated 4 times, and then dried at 80 °C for 1-2 h. After washing with deionized water and ethanol several times, the foam was vacuum dried. (2) Immerse the electrode obtained in step (1) in 15 mL of 0.1 mol / L ferric chloride solution and 0.1 mol / L sodium thiosulfate solution for 1 h, take it out and dry it at 80°C for 1-2 h, wash it with deionized water and ethanol several times, and then vacuum dry it; (3) The electrode obtained in step (2) was subjected to 20 cycles of cyclic voltammetry in 1 mol / L potassium hydroxide solution with a voltage range of 0.1 - 1.9 V (V vs. Hg / HgO) to obtain an oxygen evolution electrode modified with oxygen-containing boron anions and oxygen-containing sulfur anions (denoted as Ni / NiFe(S)OH-BO).

[0057] The oxygen evolution performance test curve of the Ni / NiFe(S)OH-BO oxygen evolution electrode prepared in Example 6 of this example is as Figure 13 shown. It can be seen from Figure 13 that the prepared Ni / NiFe(S)OH-BO oxygen evolution electrode only needs 245 mV and 382 mV to drive a current density of 0.1 A / cm 2 and 1 A / cm 2 .

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the protection scope of the claims of the present invention.

Claims

1. An oxygen anion-modified oxygen evolution electrode for AEMWE, characterized in that: The oxygen anion modified oxygen evolution electrode uses a porous conductive material as a substrate, introduces oxygen-containing borate anions through rapid alternating impregnation, then introduces a second cation and an oxygen-containing anion through impregnation treatment, and finally obtains the oxygen anion modified oxygen evolution electrode through cyclic voltammetry electrochemical activation treatment.

2. A preparation method of the oxygen anion modified oxygen evolution electrode for AEMWE according to claim 1, characterized in that: It includes the following steps: S1. Alternately impregnate the treated porous conductive substrate in a solution containing a transition metal source and a solution containing a boron source for several times. After taking it out, dry it at 80 °C for 1-2 h, wash it several times with deionized water and ethanol, and then dry it in vacuum to obtain Electrode 1; S2. Immerse Electrode 1 obtained in S1 in a mixed solution containing an iron source and different anions or alternately impregnate it in a solution containing iron ions and a solution containing different anions for several times. After taking it out, dry it at 80 °C for 1-2 h, wash it several times with deionized water and ethanol, and then dry it in vacuum to obtain Electrode 2; S3. Perform cyclic voltammetry treatment on Electrode 2 obtained in S2 in a potassium hydroxide solution to obtain the oxygen anion modified oxygen evolution electrode.

3. The preparation method of an oxygen - containing anion - modified oxygen evolution electrode for AEMWE according to claim 2, wherein: The porous conductive substrate described in S1 includes any one of nickel foam, iron foam, cobalt foam, copper foam, nickel-iron foam or cobalt-iron foam; The treatment method of the porous conductive substrate is as follows: ultrasonically treat it with acetone, hydrochloric acid, deionized water and ethanol for 20 min respectively to remove impurities on the surface of the porous conductive substrate, and then dry it at 80 °C.

4. The preparation method of an oxygen-containing anion modified oxygen evolution electrode for AEMWE according to claim 2, characterized in that: The transition metal source described in S1 includes any soluble nickel salt or cobalt salt; The concentration of the solution containing the transition metal source is 0.05-0.5 mol / L.

5. The preparation method of an oxygen - containing anion - modified oxygen evolution electrode for AEMWE according to claim 2, characterized in that: The boron source described in S1 is sodium borohydride; The molar ratio of the transition metal to sodium borohydride is 1:

3.

6. The preparation method of an oxygen anion modified oxygen evolution electrode for AEMWE according to claim 2, characterized in that: The iron source described in S2 includes any soluble iron salt; The concentration of the solution containing iron ions is 0.05-0.5 mol / L.

7. The preparation method of an oxygen-containing anion modified oxygen evolution electrode for AEMWE according to claim 2, characterized in that: The anions described in S2 include selenious acid, potassium dihydrogen phosphate or sodium thiosulfate.

8. The preparation method of an oxygen - containing anion - modified oxygen evolution electrode for AEMWE according to claim 2, characterized in that: The concentration of the potassium hydroxide solution described in S3 is 1-6 mol / L.

9. The preparation method of an oxygen anion modified oxygen evolution electrode for AEMWE according to claim 2, characterized in that: The range of cyclic voltammetry scanning described in S3 is 0.1-1.9 V (V vs. Hg / HgO).

10. The preparation method of an oxygen-containing anion modified oxygen evolution electrode for AEMWE according to claim 2, characterized in that: The number of cycles of cyclic voltammetry scanning described in S3 is ≥20.

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