Preparation method of ferronickel-based nanosheet/foamed nickel oxygen evolution reaction electrode material

Abstract

The invention provides a preparation method of a ferronickel-based nanosheet / foamed nickel oxygen evolution reaction electrode material, and solves the problems that the preparation process of an existing ferronickel-based electrode material for oxygen evolution reaction is tedious, the binding power of a nickel-iron-based catalyst is relatively low under high current density, active components are easy to fall off along with bubbles, and performance is quickly attenuated consequently . According to the preparation method, foamed nickel is used as a matrix, and the ferronickel-based nanosheet / foamed nickel oxygen evolution reaction electrode material is obtained through in-situ corrosion and electrochemical reconstruction by utilizing etching of ferric ions to nickel and coordination of phytic acid to nickel and iron ions.

Description

technical field

[0001] The invention belongs to the technical field of electrochemistry, and in particular relates to a preparation method of a nickel-iron-based nanosheet / foamed nickel oxygen evolution reaction electrode material. Background technique

[0002] With the rapid development of hydrogen-oxygen fuel cell technology, the large-scale production of hydrogen has attracted much attention. Hydrogen production by alkaline electrolysis of water is considered to be a green and sustainable way to produce hydrogen. Hydrogen production by alkaline electrolysis of water is divided into two half-reactions, which are the hydrogen evolution reaction at the cathode and the oxygen evolution reaction at the anode. Among them, the oxygen evolution reaction at the anode is a four-electron process, which requires a higher reaction energy barrier and a higher overpotential, which will waste a lot of electric energy, and requires an efficient catalyst to reduce its cost. Oxygen evolut...

Examples

Embodiment 1

[0029] Sodium hydroxide was used to adjust the pH of the phytic acid solution to 6, wherein the concentration of phytic acid was 15 mmol / L, and the nickel foam was soaked in the above solution at room temperature for 10 min. Then the nickel foam was transferred to ferric nitrate solution and left to stand for 10 min, wherein the concentration of ferric nitrate solution was also 15mmol / L. Repeat the above process 5 times, take out the nickel foam, wash and dry. Finally, the modified nickel foam was directly used as an electrode, and the nickel-iron-based nanosheet / nickel foam oxygen evolution reaction electrode material (NiFe LDH / NF) was obtained by in-situ electrochemical activation by cyclic voltammetry, and the cycle range was 1.0V- 2.0V (vs.RHE), scan rate is 2mV / s, cycle 5 times. refer to figure 1 , nickel-iron-based nanosheets are distributed on the surface of nickel foam, with a length of 0.5-5 μm, and there is a porous structure on the surface of nickel foam that is e...

Embodiment 2

[0034]Soak the nickel foam in a phytic acid solution with a pH of 8 regulated by potassium hydroxide, where the concentration of phytic acid is 5 mmol / L, and let it stand at room temperature for 2 hours. Then the nickel foam was transferred to the ferric sulfate solution and allowed to stand for 5 minutes, wherein the concentration of the ferric sulfate solution was 45mmol / L. Repeat the above process 2 times, take out the nickel foam, wash and dry. Finally, the modified nickel foam is directly used as an electrode, and the nickel-iron-based nanosheet / foam nickel oxygen evolution reaction electrode material is obtained by in-situ electrochemical activation by linear sweep voltammetry, and the scanning range is 1.0V-2.0V (vs. RHE), the sweep speed is 2mV / s, and the sweep is 10 times.

Embodiment 3

[0036] The pH of the phytic acid solution was adjusted to 3 by tris buffer solution, and the nickel foam was soaked in the above solution, wherein the concentration of phytic acid was 45mmol / L, and allowed to stand at room temperature for 5min. Then the nickel foam was transferred to ferric chloride solution and left to stand for 2h, wherein the concentration of ferric chloride solution was 5mmol / L. Repeat the above process 10 times, take out the nickel foam, wash and dry it. Finally, the modified nickel foam is directly used as an electrode, and the in-situ electrochemical activation is performed by a constant current method to obtain a nickel-iron-based nanosheet / nickel foam oxygen evolution reaction electrode material, where the current density is 500mA cm -2 , the time is 30min.

technical field

[0001] The invention belongs to the technical field of electrochemistry, and in particular relates to a preparation method of a nickel-iron-based nanosheet / foamed nickel oxygen evolution reaction electrode material. Background technique

[0002] With the rapid development of hydrogen-oxygen fuel cell technology, the large-scale production of hydrogen has attracted much attention. Hydrogen production by alkaline electrolysis of water is considered to be a green and sustainable way to produce hydrogen. Hydrogen production by alkaline electrolysis of water is divided into two half-reactions, which are the hydrogen evolution reaction at the cathode and the oxygen evolution reaction at the anode. Among them, the oxygen evolution reaction at the anode is a four-electron process, which requires a higher reaction energy barrier and a higher overpotential, which will waste a lot of electric energy, and requires an efficient catalyst to reduce its cost. Oxygen evolut...

Examples

Embodiment 1

[0029] Sodium hydroxide was used to adjust the pH of the phytic acid solution to 6, wherein the concentration of phytic acid was 15 mmol / L, and the nickel foam was soaked in the above solution at room temperature for 10 min. Then the nickel foam was transferred to ferric nitrate solution and left to stand for 10 min, wherein the concentration of ferric nitrate solution was also 15mmol / L. Repeat the above process 5 times, take out the nickel foam, wash and dry. Finally, the modified nickel foam was directly used as an electrode, and the nickel-iron-based nanosheet / nickel foam oxygen evolution reaction electrode material (NiFe LDH / NF) was obtained by in-situ electrochemical activation by cyclic voltammetry, and the cycle range was 1.0V- 2.0V (vs.RHE), scan rate is 2mV / s, cycle 5 times. refer to figure 1 , nickel-iron-based nanosheets are distributed on the surface of nickel foam, with a length of 0.5-5 μm, and there is a porous structure on the surface of nickel foam that is e...

Embodiment 2

[0034]Soak the nickel foam in a phytic acid solution with a pH of 8 regulated by potassium hydroxide, where the concentration of phytic acid is 5 mmol / L, and let it stand at room temperature for 2 hours. Then the nickel foam was transferred to the ferric sulfate solution and allowed to stand for 5 minutes, wherein the concentration of the ferric sulfate solution was 45mmol / L. Repeat the above process 2 times, take out the nickel foam, wash and dry. Finally, the modified nickel foam is directly used as an electrode, and the nickel-iron-based nanosheet / foam nickel oxygen evolution reaction electrode material is obtained by in-situ electrochemical activation by linear sweep voltammetry, and the scanning range is 1.0V-2.0V (vs. RHE), the sweep speed is 2mV / s, and the sweep is 10 times.

Embodiment 3

[0036] The pH of the phytic acid solution was adjusted to 3 by tris buffer solution, and the nickel foam was soaked in the above solution, wherein the concentration of phytic acid was 45mmol / L, and allowed to stand at room temperature for 5min. Then the nickel foam was transferred to ferric chloride solution and left to stand for 2h, wherein the concentration of ferric chloride solution was 5mmol / L. Repeat the above process 10 times, take out the nickel foam, wash and dry it. Finally, the modified nickel foam is directly used as an electrode, and the in-situ electrochemical activation is performed by a constant current method to obtain a nickel-iron-based nanosheet / nickel foam oxygen evolution reaction electrode material, where the current density is 500mA cm -2 , the time is 30min.

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