阅读说明：本技术 一种具有多级结构的NiFe-PBAs-F催化剂及其制备方法与应用 (NiFe-PBAs-F catalyst with multi-stage structure and preparation method and application thereof ) 是由 郑昭科 马法豪 黄柏标 王泽岩 程合锋 王朋 刘媛媛 张晓阳 张倩倩 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种具有多级结构的NiFe-PBAs-F催化剂及其制备方法和应用,包括如下步骤：将泡沫镍在镍盐和六亚甲基四胺的混合溶液中反应,得到Ni(OH)-2纳米片；将在泡沫镍基底上生长的Ni(OH)-2纳米片放入镍盐、柠檬酸钠和铁氰化钾的混合溶液中,反应,制得NiFe-PBAs@Ni(OH)-2多级结构；将制得的NiFe-PBAs@Ni(OH)-2多级结构与NH-4F在惰性氛围中混合热处理,得到具有多级结构的NiFe-PBAs-F催化剂。本发明中的具有多级结构的NiFe-PBAs-F催化剂能够保持原有NiFe-PBAs的框架结构,能够提供更便利的物质传输通道。此外,该催化剂在OER过程中实现了剧烈的重构,生成了更多的羟基氧镍和氢氧化镍。(The invention discloses a NiFe-PBAs-F catalyst with a multi-stage structure and a preparation method and application thereof, and the preparation method comprises the following steps: the foam nickel reacts in the mixed solution of nickel salt and hexamethylenetetramine to obtain Ni (OH) 2 Nanosheets; ni (OH) to be grown on a foamed nickel substrate 2 Putting the nano-sheets into a mixed solution of nickel salt, sodium citrate and potassium ferricyanide, and reacting to obtain NiFe-PBAs @ Ni (OH) 2 A multi-level structure; the NiFe-PBAs @ Ni (OH) obtained 2 Multilevel structure and NH 4 And F is subjected to mixing heat treatment in an inert atmosphere to obtain the NiFe-PBAs-F catalyst with the multi-stage structure. The NiFe-PBAs-F catalyst with the multi-stage structure can keep the original frame structure of the NiFe-PBAs and can provide a more convenient substance transmission channel. In addition, the catalyst realizes violent reconstruction in the OER process, and generates more hydroxyl nickel oxide and nickel hydroxide.)

1. A preparation method of a NiFe-PBAs-F catalyst with a multi-stage structure is characterized by comprising the following steps: the method comprises the following steps:

the foam nickel reacts in the mixed solution of nickel salt and hexamethylenetetramine to obtain Ni (OH)₂Nanosheets;

ni (OH) to be grown on a foamed nickel substrate₂Putting the nano-sheets into a mixed solution of nickel salt, sodium citrate and potassium ferricyanide, reacting, standing for a set time after the reaction to obtain NiFe-PBAs @ Ni (OH)₂A multi-level structure;

the NiFe-PBAs @ Ni (OH) obtained₂Multilevel structure and NH₄And F is subjected to heat treatment reaction in an inert atmosphere to obtain the NiFe-PBAs-F catalyst with a multi-stage structure.

2. The method for preparing a NiFe-PBAs-F catalyst having a multi-stage structure according to claim 1, wherein: the pretreatment method of the foamed nickel comprises the following steps: cleaning with hydrochloric acid, acetone and ethanol in sequence;

further, the pretreated nickel foam is placed in ethanol for later use.

3. The method for preparing a NiFe-PBAs-F catalyst having a multi-stage structure according to claim 1, wherein: preparation of Ni (OH)₂The nickel salt of the nano sheet is nickel nitrate;

furthermore, the concentration of the nickel nitrate is 15-20g/L, and the concentration of the hexamethylenetetramine is 15-20 g/L.

4. The method for preparing a NiFe-PBAs-F catalyst having a multi-stage structure according to claim 1, wherein: ni (OH)₂The preparation temperature of the nano-sheets is 90-110 ℃, and the preparation time is 8-12 h;

further, Ni (OH)₂The preparation temperature of the nano-sheet is 95-105 ℃, and the preparation time is 9-11 h;

still further, Ni (OH)₂The preparation temperature of the nano-sheet is 100 ℃, and the preparation time is 10 h.

5. The method for preparing a NiFe-PBAs-F catalyst having a multi-stage structure according to claim 1, wherein: NiFe-PBAs @ Ni (OH)₂The preparation temperature of the multilevel structure is 35-45 ℃, and the preparation time is 0.8-1.2 h;

further, NiFe-PBAs @ Ni (OH)₂The preparation temperature of the multilevel structure is 40 ℃, and the preparation time is 1 h;

still further, NiFe-PBAs @ Ni (OH)₂When the multilevel structure is prepared, the standing time after the reaction is 5-7h, preferably 6 h.

6. The method for preparing a NiFe-PBAs-F catalyst having a multi-stage structure according to claim 1, wherein: during the heat treatment reaction, ammonium fluoride is placed at a distance from NiFe-PBAs @ Ni (OH)₂The multilevel structure is 0.5-2.5cm, preferably 2 cm.

7. The method for preparing a NiFe-PBAs-F catalyst having a multi-stage structure according to claim 1, wherein: before heat treatment, carrying out exhaust treatment on the tube furnace to remove oxygen in the tube furnace;

further, the inert atmosphere during the heat treatment reaction is argon atmosphere;

further, the temperature of the heat treatment reaction is 340-.

8. A NiFe-PBAs-F catalyst with a multi-stage structure, which is prepared by the preparation method of any one of claims 1 to 7.

9. Use of the NiFe-PBAs-F catalyst having a multi-stage structure according to claim 8 for the electrocatalytic oxygen production.

10. The use of the NiFe-PBAs-F catalyst having a multi-stage structure according to claim 8 for electrocatalytic total hydrolysis.

Technical Field

The invention belongs to the technical field of clean energy and electrochemistry, and particularly relates to a NiFe-PBAs-F catalyst with a multi-stage structure, and a preparation method and application thereof.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

Currently, the energy crisis and environmental pollution problems are increasingly highlighted, and the development and search of new clean energy technologies to provide chemicals required by human beings is a key point of attention of all human beings. The electric energy is used as clean energy, can be provided by solar power generation, and belongs to inexhaustible energy. In recent years, the use of electrical energy to produce chemicals required by humans has been favored by researchers. The technology of electrochemical water decomposition for storing electric energy into high-calorific-value clean chemical energy hydrogen is considered to have great application potential in solving the global energy crisis and environmental pollution problems. However, the key factor limiting the efficiency of electrocatalytic decomposition of water is not in the hydrogen evolution reaction, but in the slow kinetics of the oxygen evolution reaction. Therefore, the development of cheap and efficient electrocatalytic oxygen evolution catalyst is very important for the industrial application of electrocatalytic decomposition of water.

Prussian Blue Analogues (PBAs) are connected with metal ions by cyanogen bond ligands, have adjustable metal ions and larger specific surface area and are considered as ideal precursors. Different materials such as nitride, phosphide, sulfide and the like can be prepared by utilizing the pyrolysis of the material under different atmospheres, and the materials are widely applied to the aspects of electro-catalysis hydrogen production, oxygen production and the like. However, the cyanide bonds are rapidly removed during pyrolysis of PBAs, causing metal ion aggregation and collapse of the PBAs metal backbone. This results in derivatives of PBAs that do not fully exploit the structural advantages of the initial PBAs, are not conducive to mass transport during electrocatalytic oxygen production, and ultimately lead to the generation of higher overpotentials for oxygen evolution reactions. In addition, surface restructuring of the material is also critical for OER catalysts. During the electrocatalytic oxygen evolution process, the material surface reforms and forms oxyhydroxides/hydroxides, which are considered to be the most dominant active sites in the oxygen production process. Therefore, how to solve the problem of rapid removal of the cyano bond at high temperature leading to skeleton collapse of PBAs, reduction of specific surface area, and how to form more hydroxide and oxyhydroxide during OER reconstitution is considered as a major bottleneck for the realization of industrial electrocatalytic water decomposition of PBAs materials.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a NiFe-PBAs-F catalyst with a multi-stage structure, and a preparation method and application thereof. The NiFe-PBAs-F catalyst with the multi-stage structure can keep the original frame structure of the NiFe-PBAs and can provide a more convenient substance transmission channel. In addition, the catalyst realizes violent reconstruction in the OER process, and generates more hydroxyl nickel oxide and nickel hydroxide. Due to the advantages, the prepared NiFe-PBAs-F catalyst can realize lower oxygen generation overpotential and still maintain better stability under higher current density. The material has the advantages of environment-friendly composition elements, simple and adjustable preparation method, easily obtained reaction conditions, low cost, easy industrialization and the like. Therefore, the material has good application value.

To solve the above technical problem, one or more of the following embodiments of the present invention provide the following technical solutions:

in a first aspect, the invention provides a preparation method of a NiFe-PBAs-F catalyst with a multi-stage structure, which comprises the following steps:

the foam nickel reacts in the mixed solution of nickel salt and hexamethylenetetramine to obtain Ni (OH)₂Nanosheets;

ni (OH) to be grown on a foamed nickel substrate₂Putting the nano-sheets into a mixed solution of nickel salt, sodium citrate and potassium ferricyanide, and reacting to obtain NiFe-PBAs @ Ni (OH)₂A multi-level structure;

the NiFe-PBAs @ Ni (OH) obtained₂Multilevel structure and NH₄And F is subjected to mixing heat treatment in an inert atmosphere to obtain the NiFe-PBAs-F catalyst with the multi-stage structure.

In a second aspect, the invention provides a NiFe-PBAs-F catalyst with a multi-stage structure, which is prepared by the preparation method.

In a third aspect, the invention provides application of the NiFe-PBAs-F catalyst with the multi-stage structure in electrocatalytic decomposition of water.

In a fourth aspect, the invention provides an application of the NiFe-PBAs-F catalyst with the multi-stage structure in the aspect of electrocatalytic full-hydrolysis.

Compared with the prior art, one or more technical schemes of the invention have the following beneficial effects:

the NiFe-PBAs-F catalyst with the multi-stage structure, which is prepared by the invention, is composed of two-dimensional nickel hydroxide nanosheets and nickel-iron alloy nano cubic blocks. Compared with the NiFe-PBAs-Ar catalyst, the NiFe-PBAs derivative prepared by the fluorination engineering realizes the controllable removal of the cyano bond, so that the NiFe-PBAs-F reserves the frame structure of the original NiFe-PBAs, and the multilevel structure has larger specific surface area and more favorable substance transmission channel. In addition, in the OER process, fluorine ions promote the surface reconstruction of NiFe-PBAs-F and participate in the reconstruction to form NiFeOOH doped with fluorine ions. This provides not only more active sites for OER but also more favorable adsorption of oxygenated intermediates. In addition, fluoride ion doped nifeoh also has a higher conductivity than pure nifeoh. The advantages are easy to realize, and the NiFe-PBAs-F shows excellent electrocatalytic oxygen evolution activity and stability. Is embodied asNiFe-PBAs-F at 10mA cm^-2The overpotential at the current density of (2) is 190 mV. In addition, the catalyst was used at 200mA cm^-2Also has better stability under high current density. This demonstrates the preparation of an electrocatalytic oxygen production catalyst with potential commercial utility.

The NiFe-PBAs-F catalyst has the advantages of simple and adjustable preparation method, easily obtained reaction conditions, low cost, easy industrialization, environmental friendliness, no pollution and the like. In the research process of the invention, the content of the added ammonium fluoride is controlled to regulate and control the catalytic performance of the NiFe-PBAs-F, which is beneficial to preparing the oxygen-generating electrocatalyst with more excellent performance and can help us to understand the action mechanism in more depth.

The NiFe-PBAs-F in the invention is used as a working electrode, CeO₂@ MoN as counter electrode, realizes excellent performance of 1.49V full-hydrolysis and is 10mAcm^-2The NiFe-PBAs-F catalyst prepared by the method has good electrochemical stability and has wide prospect in the aspect of practical application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 shows Ni (OH) grown on nickel foam prepared in example 1₂The morphology of the nanosheets is shown and the phases are analyzed;

FIG. 2 shows NiFe-PBAs @ Ni (OH) prepared in example 1₂XRD spectra and SEM images of the multilevel structure;

FIG. 3 is an XRD spectrum and a low power TEM image of the NiFe-PBAs-F multilevel structure and NiFe-PBAs-Ar prepared in example 1;

FIG. 4 is a graph showing the activation reconstitution curves of the multi-stage NiFe-PBAs-F structure and NiFe-PBAs-Ar produced in example 1 during oxygen generation.

FIG. 5 is an electrochemical test of NiFe-PBAs-F multilevel structures of varying fluorine content prepared in example 2.

FIG. 6 shows the electrochemical activity and stability of the NiFe-PBAs-F multilevel structure prepared in example 1.

FIG. 7 shows NiFe-PBAs-F and CeO prepared in example 3₂The schematic diagram of a two-electrode water decomposition system consisting of @ MoN, and the test of electrochemical performance, hydrogen production and oxygen production.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As introduced by the background art, aiming at the problem that serious collapse of a metal frame structure is caused by rapid removal of a cyano bond in the pyrolysis process of PBAs in the prior art, a fluorination engineering strategy is adopted, and on the basis of keeping the original skeleton structure of NiFe-PBAs, fluorine ions are introduced at the same time to promote surface reconstruction of the material in the OER process. In order to solve the technical problems, the invention provides a fluorination engineering strategy for preparing the derivatives of NiFe-PBAs, and the catalyst has low over-potential and stability under high current density and good application prospect.

In a first aspect, the invention provides a preparation method of a NiFe-PBAs-F catalyst with a multi-stage structure, which comprises the following steps:

the foam nickel reacts in the mixed solution of nickel salt and hexamethylenetetramine to obtain Ni (OH)₂Nanosheets;

ni (OH) to be grown on a foamed nickel substrate₂Putting nickel salt, sodium citrate and ferricyanide into the nano-sheetReacting in a mixed solution of potassium, standing for a set time after the reaction to prepare NiFe-PBAs @ Ni (OH)₂A multi-level structure;

the NiFe-PBAs @ Ni (OH) obtained₂Multilevel structure and NH₄And F is subjected to heat treatment reaction in an inert atmosphere to obtain the NiFe-PBAs-F catalyst with a multi-stage structure.

In some embodiments, the pretreatment method of the foamed nickel is: and sequentially adopting hydrochloric acid, acetone and ethanol for cleaning.

Further, the pretreated nickel foam is placed in ethanol for later use.

In some embodiments, Ni (OH) is prepared₂The nickel salt of the nanosheet is nickel nitrate.

Furthermore, the concentration of the nickel nitrate is 15-20g/L, and the concentration of the hexamethylenetetramine is 15-20 g/L.

In some embodiments, Ni (OH)₂The preparation temperature of the nano-sheet is 90-110 ℃, and the preparation time is 8-12 h.

Further, Ni (OH)₂The preparation temperature of the nano-sheet is 95-105 ℃, and the preparation time is 9-11 h.

Still further, Ni (OH)₂The preparation temperature of the nano-sheet is 100 ℃, and the preparation time is 10 h.

In some embodiments, NiFe-PBAs @ Ni (OH)₂The preparation temperature of the multilevel structure is 35-45 ℃, and the preparation time is 0.8-1.2 h.

Further, NiFe-PBAs @ Ni (OH)₂The preparation temperature of the multilevel structure is 40 ℃, and the preparation time is 1 h.

Still further, NiFe-PBAs @ Ni (OH)₂When the multilevel structure is prepared, the standing time after the reaction is 5-7h, preferably 6 h.

In some embodiments, the ammonium fluoride is placed at a distance from the NiFe-PBAs @ Ni (OH) during the heat treatment reaction₂The multilevel structure is 0.5-2.5cm, preferably 2 cm.

Further, before the heat treatment, the tube furnace is subjected to an exhaust treatment to remove oxygen in the tube furnace.

Further, the inert atmosphere during the heat treatment reaction is an argon atmosphere.

Further, the temperature of the heat treatment reaction is 340-.

In a second aspect, the invention provides a NiFe-PBAs-F catalyst with a multi-stage structure, which is prepared by the preparation method.

In a third aspect, the invention provides an application of the NiFe-PBAs-F catalyst with the multi-stage structure in the electrocatalytic oxygen generation.

In a fourth aspect, the invention provides an application of the NiFe-PBAs-F catalyst with the multi-stage structure in the aspect of electrocatalytic full-hydrolysis.

In order to make the technical solution of the present invention more clearly understood by those skilled in the art, the technical solution of the present invention will be described in detail below with reference to specific examples and comparative examples.

The test materials used in the following examples are all conventional in the art and are commercially available.

Example 1

A NiFe-PBAs-F catalyst with excellent electrocatalytic oxygen evolution performance and a preparation method and application thereof comprise the following steps:

(1) ultrasonic cleaning of a foamed nickel conductive substrate:

firstly, cutting with scissors to obtain a foamed nickel conductive substrate with the size of 2cm multiplied by 4cm, then respectively ultrasonically cleaning with hydrochloric acid, acetone and ethanol for 10 minutes, and finally storing in ethanol solvent.

(2) Hydrothermal Synthesis of Ni (OH)₂Nanosheet:

0.7g of nickel nitrate hexahydrate and 0.7g of hexamethylenetetramine were dissolved in 35 ml of deionized water and stirred for 15 minutes to obtain a pale green solution. Then transferring the solution into a reaction kettle with a 50ml polytetrafluoroethylene lining, placing the clean foamed nickel obtained in the step (1) in the kettle, carrying out hydrothermal reaction at 100 ℃ for 10 hours, and naturally cooling to obtain Ni (OH) uniformly grown on the foamed nickel₂Nanosheets.

(3) Preparation of NiFe-PBAs @ Ni (OH) by ion exchange method₂A multi-stage structure:

a50 mL aqueous solution containing 1.5mmol of nickel nitrate and 2.25mmol of sodium citrate was prepared and designated as A, and an aqueous solution containing 1mmol of potassium ferricyanide was prepared and designated as B. Pouring the solution B into the solution A, mixing and stirring the solution B and the solution A for 15 minutes, and mixing the Ni (OH) grown on the foamed nickel substrate obtained in the step (2)₂Putting the nano-sheets into the mixed solution, then putting the nano-sheets into warm water for a period of time, taking out the nano-sheets and standing the nano-sheets to finally obtain NiFe-PBAs @ Ni (OH)₂A multi-level structure.

(4) Preparation of NiFe-PBAs-F catalyst by fluorination strategy:

the NiFe-PBAs @ Ni (OH) obtained in the step (3)₂A multilevel structure placed in Magnetitum and 160mg of NH placed in Magnetitum₄F. Then, heat treatment was carried out at 350 ℃ for 2 hours in an atmosphere of argon. And finally obtaining the NiFe-PBAs-F catalyst with a multi-stage structure.

Example 2

The preparation method of the NiFe-PBAs-F catalyst with different fluorine contents prepared in the embodiment is the same as that of the embodiment 1, and the difference is that: the amount employed for fluorination in step (4) was changed to: 0g, 80mg and 320mg, and the prepared oxygen production catalysts are respectively marked as NiFe-PBAs-Ar, NiFe-PBAs-F-80mg and NiFe-PBAs-F-320 mg.

Ni(OH)₂Nanosheets, NiFe-PBAs @ Ni (OH)₂Multilevel structure, and morphology schematic and phase analysis of NiFe-PBAs-F catalyst:

example 1 preparation of Ni (OH)₂The XRD and SEM spectra of the nanosheets are shown in figure 1. From FIG. 1, it can be seen that Ni (OH)₂The nanosheets are grown uniformly on the foamed nickel.

NiFe-PBAs @ Ni (OH) prepared in example 1₂As shown in FIG. 2, it can be seen from FIG. 2(a) that the substance formed after ion exchange is NiFe-PBAs @ Ni (OH)₂From FIG. 2(b-c), low power TEM, it can be seen that cubic blocks of NiFe-PBAs are uniformly grown on the nickel hydroxide nanosheets.

The NiFe-PBAs-F catalyst prepared in example 1 is shown in FIG. 3, and FIG. 3(a) shows that the NiFe-PBAs are completely pyrolyzed at 350 ℃ to form FeNi₃The alloy, and in addition nickel hydroxide, is still present. Drawing (A)3(C) low-power TEM shows that the NiFe-PBAs-F catalyst reserves the frame structure of the original NiFe-PBAs and still has two-dimensional nickel hydroxide nanosheets and FeNi₃The multi-stage structure is formed by cubic blocks.

Phase analysis of the ammonium fluoride free catalyst NiFe-PBAs-Ar prepared in example 2 As shown in FIG. 3(b), the NiFe-PBAs-Ar has also completed its pyrolysis to FeNi under this condition₃The alloy, nickel hydroxide nanosheets are decomposed to NiO. As can be seen from FIG. 3(d), pyrolysis of NiFe-PBAs under argon occurs much differently than in the presence of ammonium fluoride. Pyrolysis under argon can severely disrupt the three-dimensional structure of the NiFe-PBAs, forming severely cohesive aggregates.

And (3) testing the oxygen precipitation activity of the electrochemically decomposed water:

1. the test method comprises the following steps:

the electrochemical oxygen production test was recorded by means of an electrochemical workstation (CHI 750E) using a three-electrode cell unit. Ni (OH) prepared as in examples 1-2₂Nanosheets, NiFe-PBAs @ Ni (OH)₂The multi-stage structure is characterized in that NiFe-PBAs-F and NiFe-PBAs derivatives with different fluorination degrees are used as working electrodes, a carbon rod is used as a counter electrode, a mercury oxide electrode is used as a reference electrode, and 1M KOH is used as an electrolyte solution for testing at room temperature.

2. And (3) test results:

the activation curves of the NiFe-PBAs-F and the NiFe-PBAs-Ar prepared in the examples 1 and 2 before the electrochemical activity test are shown in FIG. 4, and it can be seen from the constant current test curve that the current density of the NiFe-PBA-F catalyst is gradually increased under the condition of constant voltage and finally reaches a steady state, which indicates that the surface of the NiFe-PBA-F catalyst undergoes violent reconstruction. In comparison, under the same test conditions, the current density of the NiFe-PBAs-Ar catalyst does not show a rising trend along with the increase of time, which shows that the reconstruction of the surface of the NiFe-PBAs-Ar catalyst is smaller.

As shown in FIG. 5(a), it can be seen that the NiFe-PBAs-F catalysts prepared in examples 1 and 2 have the most excellent electrocatalytic oxygen evolution performance at 10mA cm^-2Current ofThe overpotential at density was only 190 mV. In comparison, NiFe-PBAs-Ar, Ni (OH) at the same current density₂The nanoplate and commercial ruthenium oxide electrodes required overpotentials of 230mV, 300mV and 280mV, respectively. Similarly, at a larger ionization density (50mAcm-2), NiFe-PBAs-F needs about 250mV to drive, and for NiFe-PBAs-Ar, a larger voltage is needed to drive, and the electrochemical activity result shows that NiFe-PBAs-F with a multi-stage structure has a lower over potential, which benefits from the retention of the NiFe-PBAs-F multi-stage structure and is beneficial to the diffusion and transmission of substances. In addition, the introduction of fluorine ions promotes the surface reconstruction of the NiFe-PBAs-F catalyst and increases the active sites of oxygen evolution reaction. We also performed a related test on the stability of the NiFe-PBAs-F catalytic material, as shown in FIG. 5(b), which is at 200mAcm^-2The stability is very excellent under the condition of large current density. The ultralow overpotential and the long-time stability under the high current density indicate that the NiFe-PBAs-F catalyst prepared by the method has a great industrial application value.

The electrochemical oxygen evolution activity of other NiFe-PBAs-F catalysts with different fluorine contents prepared in example 2 is shown in FIG. 6(a), and it can be seen from the linear scanning curve that the fluorine content in the fluorination engineering has a great influence on the oxygen evolution activity of the material. NiFe-PBAs-F-160mg prepared in example 1 had the most excellent catalytic activity, and in addition, FIG. 6(b-c) shows that it also had the lowest Tafel slope and the lowest interfacial charge transfer resistance.

In order to further examine the industrial application prospect of the catalyst, the NiFe-PBAs-F catalyst prepared in example 1 was used as an anode, and CeO was used₂Construction of 2 electrode System Total hydrolysis with @ MoN as cathode is shown in FIG. 7 (a). FIG. 7(b) is a linear voltammogram showing that the two-electrode system requires only 1.49V to drive 10mA cm^-2The current of (2). This shows superior water splitting ability among many catalysts. In addition, the hydrogen and oxygen generation were quantitatively analyzed by chromatography. As shown in fig. 7(C), the volume ratio of hydrogen to oxygen produced was close to 2:1, indicating that the faradaic efficiency of total hydrolysis was close to 100%.

Finally, the stability of the double electrodes is also tested, and the result shows that the stability of the double electrodes is excellent, and the huge industrial application prospect of the NiFe-PBAs-F catalyst is proved again.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.