A multi-component catalytic electrode and its preparation method and application in electrolyzing water to produce oxygen

Abstract

A multi-catalytic electrode and its preparation method and application in electrolyzing water to produce oxygen. The multi-catalytic electrode is a high-entropy alloy electrode with surface modification based on corrosion engineering, and is prepared by the following method: including selecting FeCoNiM high-entropy alloy as the conductive substrate of the electrode and the metal source during surface modification, processing into a substrate sheet, and removing the surface oxide layer of the substrate sheet; preparing a mixed solution of NaOH and NaCl; placing the substrate sheet in a hydrothermal kettle liner filled with a mixed solution of NaOH and NaCl; heating the hydrothermal kettle at a set temperature for a set time, so that the substrate sheet and the mixed solution of NaOH and NaCl undergo a hydrothermal reaction, and the FeCoNiM high-entropy alloy of the substrate sheet and the mixed solution of NaOH and NaCl undergo a corrosion reaction at high temperature and generate multi-catalytic active components in situ; and cooling the hydrothermal kettle to room temperature, washing the surface of the substrate sheet with deionized water and alcohol in turn to remove the residual solution, and obtaining a surface-modified FeCoNiM high-entropy alloy electrode after drying. The present invention also provides an application of the multi-catalytic electrode for electrolyzing water to produce oxygen.

Description

Technical Field

[0001] The invention relates to inorganic material synthesis technology, in particular to a multi-component catalytic electrode and a preparation method thereof based on a corrosion engineering surface modified high entropy alloy electrode and its application in electrolyzing water to produce oxygen. Background Art

[0002] Among various technologies for producing hydrogen fuel, seawater electrolysis technology converts electricity into hydrogen, converts seawater into fresh water, and avoids the emission of harmful gases. It is one of the most promising energy conversion technologies. However, the sluggish kinetics of the oxygen evolution reaction (OER) has become a bottleneck of the technology, limiting the development of seawater electrolysis technology. At the same time, the complex electrocatalyst preparation process has become the main difficulty in promoting the large-scale industrial production of catalysts. Therefore, the use of a simple and efficient process to prepare low-cost, high-performance and long-term stable seawater splitting OER electrocatalysts is very important for alleviating the energy crisis and the development of catalysts. Precious metals Ir, Ru and their oxides are considered to be the best performing OER electrocatalysts, but their low reserves and high costs limit their wide application. Studies have found that alloys and compounds of some transition metals such as iron, cobalt, nickel, etc. also have excellent OER electrocatalytic performance, and these metals have the advantages of large reserves and low costs.

[0003] At the same time, electrocatalyst preparation technology usually requires metal salts as raw materials, and waste liquid containing heavy metals and nitrate ions needs to be treated after the process is completed, and the electrocatalytic active components produced need to be fixed to the conductive substrate with the help of a binder. However, the binder not only hinders the catalytic activity of the electrocatalyst, but also causes the life of the electrocatalyst to be limited by the quality of the binder. This not only increases the manufacturing cost of the electrocatalyst, but also increases the difficulty of the preparation process. In order to alleviate the problem of freshwater resources, the development of electrocatalytic hydrogen and oxygen production technologies using seawater as raw materials has great prospects, among which oxygen production technology is crucial, and a simple and efficient method for preparing highly active electrocatalysts for electrocatalytic cracking of seawater to produce oxygen is urgently needed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a multi-catalytic electrode and a simple and efficient preparation method of a high-entropy alloy electrode based on corrosion engineering surface modification, and its application in electrolysis of water, especially in cracking alkaline seawater to produce oxygen, in order to improve the activity and stability of FeCoNiM high-entropy alloy electrodes in cracking alkaline seawater to produce oxygen.

[0005] In order to achieve the above object, the present invention provides a method for preparing a multi-element catalytic electrode, wherein a high entropy alloy electrode is surface-modified based on corrosion engineering, comprising the following steps:

[0006] S100, selecting FeCoNiM high entropy alloy as the conductive substrate of the electrode and the metal source for surface modification, processing it into a substrate sheet of a set size, and removing the surface oxide layer of the substrate sheet;

[0007] S200, preparing a mixed solution of NaOH and NaCl;

[0008] S300, placing the substrate sheet into a hydrothermal kettle filled with a mixed solution of NaOH and NaCl;

[0009] S400, heating the hydrothermal kettle at a set temperature and for a set time, so that the substrate sheet undergoes a hydrothermal reaction with the mixed solution of NaOH and NaCl, and the FeCoNiM high entropy alloy of the substrate sheet undergoes a corrosion reaction with the mixed solution of NaOH and NaCl at a high temperature and generates multi-catalytic active components in situ; and

[0010] S500, cooling the hydrothermal autoclave to room temperature, washing the surface of the substrate sheet with deionized water and alcohol in sequence to remove residual solution, and obtaining a surface-modified FeCoNiM high-entropy alloy electrode after drying.

[0011] The above-mentioned method for preparing a multi-catalytic electrode, wherein the metal element M in the FeCoNiM high-entropy alloy is any one or more of Al, Ti, V, Mn, Cr, Cu, Zn, Nb, Mo, Sn, W or Bi.

[0012] The above-mentioned method for preparing a multi-catalytic electrode, wherein the in-situ generated multi-catalytic active component is a multi-LDHs catalytic active component synthesized in situ on the surface of the substrate sheet, the multi-LDHs catalytic active component includes an LDHs sheet, and the metal elements and oxygen elements contained in the FeCoNiM high entropy alloy coexist and are evenly distributed in the LDHs sheet.

[0013] In the above-mentioned method for preparing a multi-component catalytic electrode, in step S200, the concentration of the NaOH solution is 0.1M to 9M, and the concentration of the NaCl solution is 0M to 0.5M.

[0014] In the above-mentioned method for preparing a multi-component catalytic electrode, the set temperature of the hydrothermal kettle heating is 100° C. to 150° C., and the set time is 1 hour to 24 hours.

[0015] In the above-mentioned method for preparing a multi-element catalytic electrode, step S100 further comprises:

[0016] S101, processing the FeCoNiM high entropy alloy into a substrate sheet with a size of 10-15 mm×10 mm×0.5 mm;

[0017] S102, polishing with sandpaper of various types in sequence to remove the metal oxide layer on the surface of the substrate sheet;

[0018] S103, rinsing or ultrasonically washing the substrate sheet with deionized water; and

[0019] S104, drying the base sheet and placing it in a drying oven for later use.

[0020] In the above-mentioned method for preparing a multi-element catalytic electrode, in step S102, the types of sandpaper include 240#, 400#, 800#, 1200# and 2000#.

[0021] In the above-mentioned method for preparing a multi-element catalytic electrode, in step S500, the surface of the substrate sheet is rinsed 3 to 5 times with deionized water.

[0022] In order to better achieve the above-mentioned purpose, the present invention also provides a multi-catalytic electrode, which is a surface-modified FeCoNiM high-entropy alloy electrode obtained by the above-mentioned preparation method of the multi-catalytic electrode.

[0023] In order to better achieve the above-mentioned purpose, the present invention also provides an application of a multi-catalytic electrode for electrolyzing water to produce oxygen, wherein a surface-modified FeCoNiM high-entropy alloy electrode obtained by the above-mentioned preparation method of the multi-catalytic electrode is used to electrolyze water to produce oxygen.

[0024] The above-mentioned application of the multi-catalytic electrode to electrolyze water to produce oxygen, wherein the electrolyzed water to produce oxygen is to crack alkaline seawater to produce oxygen.

[0025] The technical effects of the present invention are:

[0026] The preparation method of the FeCoNiM high entropy alloy electrode of the present invention is simple, the experimental cycle is short, no external metal salt source is required, and the element types can be controlled; the prepared FeCoNiM high entropy alloy electrode can be used for electrolysis of water to produce oxygen and electrolysis of alkaline seawater to produce oxygen, etc.; the complex process of preparing multi-catalytic electrodes can be significantly reduced, and the prepared electrode has high electrocatalytic activity and has good application prospects.

[0027] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a scanning electron microscope (SEM) image of a surface-modified FeCoNiCrAl high entropy alloy according to an embodiment of the present invention;

[0029] Figure 2 This is a scanning electron microscope (SEM) image of a surface-modified FeCoNiCrMo high entropy alloy according to an embodiment of the present invention;

[0030] Figure 3 The transmission electron microscope (TEM) and composition distribution diagram of the in-situ grown multi-catalyst of the surface-modified FeCoNiCrAl high-entropy alloy according to one embodiment of the present invention;

[0031] Figure 4 The transmission electron microscope (TEM) and composition distribution diagram of the in-situ grown multi-catalyst of the surface-modified FeCoNiCrMo high-entropy alloy according to one embodiment of the present invention;

[0032] Figure 5 The oxygen production performance of water electrolysis of the surface-modified FeCoNiCrAl high-entropy alloy electrode according to one embodiment of the present invention;

[0033] Figure 6 The oxygen production performance of water electrolysis of the surface-modified FeCoNiCrMo high-entropy alloy electrode according to one embodiment of the present invention;

[0034] Figure 7 The oxygen production performance of the surface-modified FeCoNiCrAl high-entropy alloy electrode in electrolysis of alkaline seawater according to one embodiment of the present invention;

[0035] Figure 8 The oxygen production performance of the surface-modified FeCoNiCrMo high-entropy alloy electrode in electrolysis of alkaline seawater according to one embodiment of the present invention. DETAILED DESCRIPTION

[0036] The structural principle and working principle of the present invention are described in detail below in conjunction with the accompanying drawings:

[0037] The multi-element catalytic electrode of the present invention is a high entropy alloy electrode based on corrosion engineering surface modification, which is prepared by the following method, and the preparation method comprises the following steps:

[0038] Step S100, selecting FeCoNiM high entropy alloy as the conductive substrate of the electrode and the metal source for surface modification, processing it into a substrate sheet of a set size, and removing the surface oxide layer of the substrate sheet;

[0039] Step S200, preparing a NaOH solution, or a mixed solution of NaOH and NaCl;

[0040] Step S300, placing the substrate sheet into a hydrothermal kettle filled with a NaOH solution or a mixed solution of NaOH and NaCl;

[0041] Step S400, heating the hydrothermal kettle at a set temperature for a set time to allow the substrate sheet to undergo a hydrothermal reaction with the mixed solution of NaOH and NaCl, wherein the FeCoNiM high entropy alloy of the substrate sheet undergoes a corrosion reaction with the mixed solution of NaOH and NaCl at a high temperature and generates multi-catalytic active components in situ; and

[0042] Step S500, cooling the hydrothermal autoclave to room temperature, washing the surface of the substrate sheet with deionized water or alcohol for 3 to 5 times to remove residual solution, and obtaining a surface-modified FeCoNiM high-entropy alloy electrode after drying.

[0043] Wherein, the metal element M in the FeCoNiM high entropy alloy is any one or more of Al, Ti, V, Mn, Cr, Cu, Zn, Nb, Mo, Sn, W or Bi. The in-situ generated multi-catalytic active component is a multi-layered multi-hydroxide (LDHs) catalytic active component synthesized in-situ on the surface of the substrate sheet, the multi-layered multi-hydroxide (LDHs) catalytic active component includes an LDHs sheet, and the metal elements and oxygen elements contained in the FeCoNiM high entropy alloy coexist and are evenly distributed in the LDHs sheet.

[0044] In this embodiment, in step S200, the concentration of the NaOH solution is 0.1M to 9M, and the concentration of the NaCl solution is 0M to 0.5M. The set temperature of the hydrothermal kettle heating is 100°C to 150°C, and the set time is 1h to 24h.

[0045] Wherein, step S100 may further include:

[0046] Step S101, processing the FeCoNiM high entropy alloy into a substrate sheet with a size of 10-15 mm×10 mm×0.5 mm;

[0047] Step S102, using various types of sandpaper to polish in sequence to remove the metal oxide layer on the surface of the substrate sheet, wherein the types of sandpaper may include 240#, 400#, 800#, 1200# and 2000#;

[0048] Step S103, rinsing or ultrasonically washing the substrate sheet with deionized water; and

[0049] Step S104, drying the base sheet and placing it in a drying oven for later use.

[0050] The present invention also provides an application of the surface-modified FeCoNiM high-entropy alloy electrode obtained by the above-mentioned preparation method of the multi-catalyst electrode to electrolyze water to produce oxygen. The electrolyzed water to produce oxygen can be produced by cracking alkaline seawater.

[0051] The following is a detailed description of the implementation methods of the present invention for surface-modified FeCoNiCrAl and FeCoNiCrMo high-entropy alloy electrodes and their application in electrolyzing water to produce oxygen, using specific examples:

[0052] Example 1

[0053] For the surface modified FeCoNiCrAl high entropy alloy electrode, the preferred preparation method comprises the following steps:

[0054] Step S100, FeCoNiCrAl high entropy alloy is selected as the conductive substrate of the electrode and the metal source for surface modification, and processed into a sheet with a size of 10 mm×10 mm×0.5 mm, and the surface is polished with 240#, 400#, 800#, 1200# and 2000# sandpaper in sequence to remove the surface oxide layer;

[0055] Step S200, preparing 20 mL of a mixed solution containing 3 M NaOH and 0.3 M NaCl;

[0056] Step S300, placing the high entropy alloy and the mixed solution into the inner container of the hydrothermal kettle at the same time;

[0057] Step S400, the hydrothermal kettle is placed at 120° C. and heated for 12 hours to perform a hydrothermal reaction;

[0058] Step S500: After the reaction is completed, the high entropy alloy sheet is cooled to room temperature, and the high entropy alloy sheet is taken out, rinsed with deionized water and alcohol in turn, and dried to obtain a surface-modified FeCoNiCrAl high entropy alloy electrode.

[0059] See also Figure 1 , Figure 1 This is a scanning electron microscope (SEM) image of a surface-modified FeCoNiCrAl high-entropy alloy according to an embodiment of the present invention. Figure 1 The morphology of the surface of the surface-modified FeCoNiCrAl high-entropy alloy electrode is shown. Multi-component LDHs catalytic active components are synthesized in situ on the surface. The LDHs flakes are interlaced with each other, with a size of about 1 μm and a thickness of about 50 nm.

[0060] See also Figure 3 , Figure 3 This is a transmission electron microscope (TEM) and composition distribution diagram of the in-situ grown multi-catalyst of the surface-modified FeCoNiCrAl high-entropy alloy according to one embodiment of the present invention. Figure 3 The transmission electron microscope photo shows the extremely thin structure of LDHs on the surface of the surface-modified FeCoNiCrAl high-entropy alloy electrode. From the energy spectrum scanning results, it can be seen that the metal elements and oxygen elements contained in the corresponding high-entropy alloy coexist and are evenly distributed in the LDHs thin sheets.

[0061] See also Figure 5, Figure 5 The oxygen production performance of the surface-modified FeCoNiCrAl high entropy alloy electrode of one embodiment of the present invention is shown in FIG. Figure 5 As shown, the FeCoNiCrAl high entropy alloy electrode sample surface-modified under the conditions of 120°C, 3M NaOH and 0.3M NaCl mixed solution hydrothermal for 12 hours has a significant improvement in electrocatalytic oxygen production performance. Figure 5 The electrocatalytic oxygen production activity of the surface modified FeCoNiCrAl high entropy alloy electrode in alkaline medium (1M KOH aqueous solution) was shown. The oxygen production current density of this electrode was 6.5 times that of the FeCoNiCrAl high entropy alloy electrode, indicating that the surface modified FeCoNiCrAl high entropy alloy electrode has good electrocatalytic oxygen production performance.

[0062] Example 2

[0063] Step S100, FeCoNiCrAl high entropy alloy is selected as the conductive substrate of the electrode and the metal source for surface modification, and processed into a sheet with a size of 10 mm×10 mm×0.5 mm, and the surface is polished with 240#, 400#, 800#, 1200# and 2000# sandpaper in sequence to remove the surface oxide layer;

[0064] Step S200, preparing 20 mL, 3M NaOH solution;

[0065] Step S300, placing the high entropy alloy and the NaOH solution into the inner tank of a hydrothermal kettle at the same time;

[0066] Step S400, the hydrothermal kettle is placed at 150° C. and heated for 8 hours to perform a hydrothermal reaction;

[0067] Step S500: After the reaction is completed, the high entropy alloy sheet is cooled to room temperature, and the high entropy alloy sheet is taken out, rinsed with deionized water and alcohol in turn, and dried to obtain a surface-modified FeCoNiCrAl high entropy alloy electrode.

[0068] See also Figure 7 , Figure 7 The oxygen production performance of the surface-modified FeCoNiCrAl high-entropy alloy electrode in alkaline seawater electrolysis is shown in Figure 1, i.e., the electrochemical test curve in alkaline seawater (1M KOH+0.5M NaCl aqueous solution). The results show that the surface-modified FeCoNiCrAl high-entropy alloy electrode can reach 10 mA cm -2 With 100mA cm -2When the current density is 272.3mV and 343.4mV, respectively, the overpotential is reduced by 77.5mV and 112mV compared with the unmodified FeCoNiCrAl high entropy alloy (349.8mV and 455.4mV), indicating that the electrode has good electrocatalytic oxygen production performance in alkaline seawater.

[0069] Example 3

[0070] For the surface modified FeCoNiCrMo high entropy alloy electrode, the preferred preparation method comprises the following steps:

[0071] Step S100, FeCoNiCrMo high entropy alloy is selected as the conductive substrate of the electrode and the metal source for surface modification, and processed into a sheet with a size of 15 mm×10 mm×0.5 mm, and the surface is polished with 240#, 400#, 800#, 1200# and 2000# sandpaper in sequence to remove the surface oxide layer;

[0072] Step S200, preparing 20 mL, 3M NaOH solution;

[0073] Step S300, placing the high entropy alloy and the NaOH solution into the inner tank of a hydrothermal kettle at the same time;

[0074] Step S400, placing the hydrothermal kettle at 130° C. and heating for 12 hours to perform a hydrothermal reaction;

[0075] Step S500: After the reaction is completed, the high entropy alloy sheet is cooled to room temperature, and the high entropy alloy sheet is taken out, rinsed with deionized water and alcohol in turn, and dried to obtain a surface-modified FeCoNiCrMo high entropy alloy electrode.

[0076] See also Figure 2 , Figure 2 FIG. 1 is a scanning electron microscope (SEM) image of a surface-modified FeCoNiCrMo high entropy alloy according to an embodiment of the present invention, that is, the surface morphology of a surface-modified FeCoNiCrMo high entropy alloy electrode. Figure 2 It can be seen that multiple LDHs catalytic active components are synthesized in situ on the surface. The LDHs flakes are intertwined and have a size between 200 and 500 nm and a thickness of about 10 nm.

[0077] See also Figure 4 , Figure 4 The transmission electron microscope (TEM) and composition distribution diagram of the in-situ growth multi-component catalyst of the surface-modified FeCoNiCrMo high entropy alloy according to one embodiment of the present invention are shown. Figure 4As shown in the transmission electron microscope photos in, the LDHs on the surface of the surface-modified FeCoNiCrMo high-entropy alloy electrode have an ultra-thin structure. From the energy spectrum scanning results, it can be seen that the chemical composition of the LDHs flakes is composed of the metal elements and oxygen elements contained in the corresponding high-entropy alloy and is evenly distributed.

[0078] See also Figure 6 , Figure 6 The oxygen production performance of the surface-modified FeCoNiCrMo high entropy alloy electrode of one embodiment of the present invention is shown in FIG. Figure 6 As shown in the figure, under the conditions of hydrothermal treatment at 130°C in 3M NaOH solution for 12 hours, the prepared surface-modified FeCoNiCrMo high-entropy alloy electrode sample has a significant improvement in OER electrocatalytic performance. In alkaline medium (1M KOH aqueous solution), the surface-modified FeCoNiCrMo high-entropy alloy electrode reaches 10 mA cm -2 With 100mA cm -2 When the current density is 250.4 mV and 308.4 mV, respectively, the overpotentials are reduced by 71.5 mV and 113.9 mV compared with the unmodified FeCoNiCrMo high entropy alloy (331.6 mV and 422.3 mV), indicating that the surface modified FeCoNiCrMo electrode has excellent electrocatalytic oxygen production performance.

[0079] Example 4

[0080] Step S100, FeCoNiCrMo high entropy alloy is selected as the conductive substrate of the electrode and the metal source for surface modification, and processed into a sheet with a size of 15 mm×10 mm×0.5 mm, and the surface is polished with 240#, 400#, 800#, 1200# and 2000# sandpaper in sequence to remove the surface oxide layer;

[0081] Step S200, preparing 20 mL of a mixed solution containing 1 M NaOH and 0.1 M NaCl;

[0082] Step S300, placing the high entropy alloy and the mixed solution into the inner container of the hydrothermal kettle at the same time;

[0083] Step S400, placing the hydrothermal kettle at 120° C. and heating for 12 hours to perform a hydrothermal reaction;

[0084] Step S500: After the reaction is completed, the high entropy alloy sheet is cooled to room temperature, and the high entropy alloy sheet is taken out, rinsed with deionized water and alcohol in turn, and dried to obtain a surface-modified FeCoNiCrMo high entropy alloy electrode.

[0085] See also Figure 8 , Figure 8The oxygen production performance of the surface-modified FeCoNiCrMo high entropy alloy electrode in electrolysis of alkaline seawater according to one embodiment of the present invention is shown in FIG. Figure 8 As shown, the FeCoNiCrMo high entropy alloy electrode sample surface-modified under the conditions of 120°C, 1 M NaOH and 0.1 M NaCl mixed solution hydrothermal for 12 hours has excellent electrocatalytic oxygen production performance. Figure 8 The results of the electrocatalytic oxygen production test of the surface-modified FeCoNiCrMo high-entropy alloy electrode in alkaline seawater (1M KOH+0.5M NaCl aqueous solution) are shown. The oxygen production current density of this electrode is three times that of the FeCoNiCrMo high-entropy alloy electrode, indicating that the electrocatalytic oxygen production performance of the FeCoNiCrAl high-entropy alloy can be improved after surface modification.

[0086] The method of modifying the high entropy alloy electrode by corrosion engineering surface of the present invention has the advantages of simple equipment, simple process, no need to add metal salts, etc. The high entropy alloy electrode prepared by the method of the present invention has high catalytic activity and the element types can be controlled, and has great application prospects.

[0087] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a multi-element catalytic electrode, characterized in that: The surface modification of high entropy alloy electrodes based on corrosion engineering includes the following steps: S100, selecting FeCoNiM high entropy alloy as the conductive substrate of the electrode and the metal source for surface modification, processing it into a substrate sheet of a set size, and removing the surface oxide layer of the substrate sheet; S200, preparing a NaOH solution, or a mixed solution of NaOH and NaCl; S300, placing the substrate sheet into a hydrothermal kettle filled with a NaOH solution or a mixed solution of NaOH and NaCl; S400, heating the hydrothermal kettle at a set temperature for a set time to allow the substrate sheet to undergo a hydrothermal reaction with the NaOH solution, or a mixed solution of NaOH and NaCl, so that the FeCoNiM high entropy alloy of the substrate sheet and the NaOH solution, or the mixed solution of NaOH and NaCl, undergo a corrosion reaction at a high temperature and in-situ generate a multi-component catalytic active component; and S500, cooling the hydrothermal autoclave to room temperature, washing the surface of the substrate sheet with deionized water and alcohol in sequence to remove residual solution, and obtaining a surface-modified FeCoNiM high-entropy alloy electrode after drying; Wherein, the metal element M in the FeCoNiM high entropy alloy is two or more of Cr, Al and Mo; The in-situ generated multi-catalytic active component is a multi-LDHs catalytic active component synthesized in-situ on the surface of the substrate sheet, the multi-LDHs catalytic active component includes an LDHs sheet, and the metal elements and oxygen elements contained in the FeCoNiM high entropy alloy coexist and are uniformly distributed in the LDHs sheet; The concentration of NaOH solution is 0.1M~9M, and the concentration of NaCl solution is 0.1M~0.5M; The set temperature of the hydrothermal kettle heating is 100° C. to 150° C., and the set time is 1 hour to 24 hours.

2. The method for preparing a multi-component catalytic electrode according to claim 1, characterized in that: Step S100 further includes: S101, processing the FeCoNiM high entropy alloy into a substrate sheet with a size of 10-15 mm×10 mm×0.5 mm; S102, polishing with sandpaper of various types in sequence to remove the metal oxide layer on the surface of the substrate sheet; S103, rinsing or ultrasonically washing the substrate sheet with deionized water; and S104, drying the base sheet and placing it in a drying oven for later use.

3. The method for preparing a multi-component catalytic electrode according to claim 2, characterized in that: In step S102, the sandpaper types include 240#, 400#, 800#, 1200# and 2000#.

4. A multi-component catalytic electrode, characterized in that: The multi-catalytic electrode is a surface-modified FeCoNiM high-entropy alloy electrode obtained by the preparation method of the multi-catalytic electrode described in any one of claims 1 to 3.

5. An application of electrolyzing water to produce oxygen by using a multi-element catalytic electrode, characterized in that: The surface-modified FeCoNiM high-entropy alloy electrode obtained by the preparation method of the multi-catalytic electrode described in any one of claims 1 to 3 is used to crack alkaline seawater to produce oxygen.

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