阅读说明：本技术 一种非贵金属电解水阳极材料及其制备方法和应用 (Non-noble metal anode material for electrolyzed water and preparation method and application thereof ) 是由 刘长影 李想 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种非贵金属电解水阳极材料及其制备方法和应用,所述阳极材料的制备方法为：在经过老化的含有锰盐、电解质和pH缓冲辅剂的电解液中电解,在导电基体表面电沉积生成锰氧化物,制得锰氧化物电极,再采用浸渍的方式,将金属M离子负载到锰氧化物电极上,最后以碱性电解质溶液作为电解液,进行电解,原位生成高活性超薄活化层MOOH负载的锰氧化物电极。本发明电极的制备过程不经过高温处理,且活化层的负载也是原位生成,不经过热处理,制备过程节能降耗,有望替代传统的贵金属氧化物电极及其它非贵金属氧化物电极,应用于电解水产氧和产氢中。(The invention discloses a non-noble metal anode material for electrolytic water, a preparation method and application thereof, wherein the preparation method of the anode material comprises the following steps: electrolyzing in an aged electrolyte containing manganese salt, electrolyte and pH buffering auxiliary agent, electrodepositing on the surface of a conductive substrate to generate manganese oxide, preparing a manganese oxide electrode, loading metal M ions on the manganese oxide electrode in a dipping mode, and finally electrolyzing by taking an alkaline electrolyte solution as the electrolyte to generate the manganese oxide electrode loaded with the high-activity ultrathin active layer MOOH in situ. The preparation process of the electrode does not need high-temperature treatment, the load of the active layer is generated in situ, and the electrode does not need heat treatment, so that the energy is saved and the consumption is reduced in the preparation process, and the electrode is expected to replace the traditional noble metal oxide electrode and other non-noble metal oxide electrodes and is applied to oxygen production and hydrogen production by electrolyzing water.)

1. A preparation method of a non-noble metal anode material for water electrolysis is characterized by comprising the following steps:

1) preparation of manganese oxide electrode:

preparing an electrolyte containing manganese salt, electrolyte and a pH buffering auxiliary agent, aging the electrolyte in a dark place at room temperature for 0.5-10 days, adding the electrolyte into an electrolytic cell, forming an electrode system by taking a conductive matrix as an anode, a saturated calomel electrode as a reference electrode and a graphite electrode, a platinum electrode or a carbon electrode as a cathode, carrying out electrolytic reaction in a steady deposition or dynamic deposition mode, and carrying out electrodeposition on the surface of the conductive matrix to generate manganese oxide so as to prepare a manganese oxide electrode;

2) loading of activating Components

Taking an aqueous solution of metal M salt as an impregnation solution, taking the manganese oxide electrode prepared in the step 1) as a carrier, and loading metal M ions on the manganese oxide electrode in an impregnation mode;

3) in situ generation of active layer

And (3) taking an alkaline electrolyte solution as an electrolyte, taking the manganese oxide electrode loaded with metal M ions in the step 2) as an anode, taking a graphite electrode, a platinum electrode or a carbon electrode as a cathode, and electrolyzing to generate the manganese oxide electrode loaded with the high-activity ultrathin activation layer MOOH in situ.

2. The method for preparing a non-noble metal anode material for electrolytic water as claimed in claim 1, wherein in step 1), the conductive substrate is an FTO glass electrode, and the aging time is 4-8 days; the pH buffering auxiliary agent in the electrolyte in the step 1) is acetic acid, the electrolyte is sodium sulfate or sodium nitrate, and the manganese salt is manganese acetate.

3. The method for preparing a non-noble metal water anode material for electrolysis according to claim 2, wherein in the electrolyte of step 1), the mass concentration of acetic acid is 0.1-10%, preferably 0.5-3%, the concentration of sodium sulfate or sodium nitrate is 0.05-1mol/L, preferably 0.05-0.5mol/L, and the concentration of manganese acetate is 0.01-0.5mol/L, preferably 0.05-0.3 mol/L.

4. The method for preparing a non-noble metal anode material for water electrolysis according to claim 1, wherein the step 1) comprises performing the electrolysis reaction by dynamic deposition, wherein the potential of the electrokinetic potential deposition is-0.2 to 1.0V vs SCE, and the cycle time is 1 to 50 times, preferably, the deposition potential is 0 to 0.8V vs SCE, and the cycle time is 5 to 20 times.

5. The method for preparing a non-noble metal anode material for electrolytic water according to claim 1, wherein in step 2), the metal M is one or more active elements selected from manganese, iron, cobalt, zinc, copper, niobium and tantalum, preferably one or more active elements selected from manganese, iron and cobalt;

the impregnation process in step 2) is as follows: firstly, immersing a manganese oxide electrode into a salt solution containing an active element, standing and immersing for a period of time, and then standing, immersing and washing for a period of time by deionized water to finish the cyclic loading of the active element; if the same or different active ingredients are loaded again, repeating the operations, and repeating the operations in the same way, and so on, and loading the ions of the active elements on the manganese oxide electrode; each active element is loaded for 1-5 times, preferably 1-2 times; wherein the concentration of the salt solution of each active element is 10-500mM, preferably 20-200 mM.

6. The method for preparing a non-noble metal anode material for electrolytic water as claimed in claim 5, wherein the metal M is iron or cobalt, impregnated Co ions are loaded on a manganese oxide electrode, and then impregnated Fe ions are loaded, and the specific process is as follows:

step a: immersing the manganese oxide electrode into a cobalt salt aqueous solution, standing and immersing for 10-3600s, taking out the manganese oxide electrode, immersing into deionized water, standing, immersing and washing for 10-3600s, and then taking out the manganese oxide electrode to finish the cyclic load of Co ions; repeating the process of loading the Co ions for 0-1 time again, so that the Co ions are circularly loaded on the manganese oxide electrode for 1-2 times in total;

step b: after the treatment in the step a is finished, immersing the Co ion-loaded manganese oxide electrode into an iron salt aqueous solution, standing and immersing for 10-3600s, taking out the electrode, immersing into deionized water, standing, immersing, washing for 10-3600s, and then taking out the electrode, namely completing the cyclic loading of Fe ions; repeating the process of loading Fe ions for 0-1 times again, so that the Fe ions are loaded on the manganese oxide electrode for 1-2 times in a circulating manner.

7. The method for preparing a non-noble metal anode material for electrolytic water as claimed in claim 6, wherein the dipping time for loading Co ions or Fe ions in step a or step b is 60-300s, preferably 100-150 s; the soaking and water washing time is 60-300s, preferably 100-150 s; the concentration of the aqueous cobalt salt solution or the aqueous iron salt solution is 10 to 500mM, preferably 20 to 200 mM.

8. The method for preparing a non-noble metal anode material for water electrolysis according to claim 1, wherein in the step 3), the alkaline electrolyte solution is an aqueous solution of KOH or NaOH with a concentration of 0.5-1.5M; the voltage of the electrolyzed water in the step 3) is 1.45-2.0V vs.

9. A non-noble metal water electrolysis anode material prepared by the method as claimed in any one of claims 1 to 8.

10. The application of the non-noble metal water electrolysis anode material in preparing hydrogen and oxygen by electrolyzing water as claimed in claim 9, wherein an aqueous solution of KOH or NaOH with a concentration of 0.5-1.5M is used as an electrolyte, the non-noble metal water electrolysis anode material is used as an anode, and a graphite electrode, a platinum electrode or a carbon electrode is used as a cathode to perform an electrolysis reaction to generate hydrogen and oxygen.

Technical Field

The invention relates to a non-noble metal anode material for electrolytic water, a preparation method and application thereof.

Background

The hydrogen and oxygen production by water electrolysis is an important direction in the fields of new energy and clean production, particularly meets the aims of carbon peak reaching and carbon neutralization proposed by the nation, and solves the problem of carbon emission caused by using fossil fuel as energy. The anode generates oxygen and the cathode generates hydrogen in the water electrolysis process, the oxygen production process is a speed control step of the whole water electrolysis process, and because the oxygen production of the anode needs four-electron transfer and also generates a complex intermediate, the overpotential is high, and the anode environment is strong in corrosivity, the problem of an anode material is solved, and the technical problem faced by the water electrolysis is solved.

In the traditional hydrogen and oxygen production by water electrolysis, a noble metal oxide coating electrode is mainly adopted, and due to the advantages of excellent performance, strong corrosion resistance and the like, in recent years, the market demand of noble metals is large, the price continuously rises, and the large-scale application development of the electrolyzed water is greatly limited. Therefore, it is important to reduce the amount of noble metal used in the coated electrode or to find alternative non-noble metal oxide electrolyzed water.

The transition metal has rich sources, low price and certain performance, and is always researched as the hot door direction of the anode material for the electrolyzed water, generally speaking, the oxygen evolution overpotential of the noble metal oxide coating electrode is 200-300mV, the oxygen evolution overpotential of the transition metal oxide electrode is 300-500mV, and fundamentally, the performance of the transition metal oxide as the anode material for the electrolyzed water is different from that of the noble metal oxide anode. How to improve the performance and stability of the non-noble metal oxide anode material is a key factor related to whether the non-noble metal oxide anode material can be used as an anode material for water electrolysis. The invention overcomes the cost problem of electrolytic water electrolysis materials, and the manganese oxide anode prepared by electrodeposition is not treated at high temperature, is soaked in active component solution, generates an ultrathin active functional layer in situ under the condition of external potential, and is hopeful to be applied to the field of hydrogen and oxygen production by non-noble metal electrolytic water in a large scale.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention aims to provide a non-noble metal water electrolysis anode material, and a preparation method and application thereof, and mainly aims to reduce the dependence of the water electrolysis anode material on noble metal materials and promote the development of the non-noble metal water electrolysis anode material. The traditional anode material for hydrogen production by electrolyzing water is prepared by adopting a noble metal oxide coating or a non-noble metal oxide coating and adopting a high-temperature roasting process, so that the energy consumption is huge, certain pollution is caused to the environment, the preparation cost of the electrode material is increased, the load of an active layer is also a step requiring high-temperature treatment, the energy consumption is further increased, and the problems of environmental pollution and cost increase are also caused. Therefore, the invention searches for the anode material with low cost and excellent performance from the concepts of energy-saving environment and clean production. The manganese oxide material has higher oxygen evolution efficiency and stability due to the conversion of different valence states, and an ultrathin active functional layer (MOOH) is generated on the surface in situ through the active component impregnation and the electrochemical process, so that the efficiency and the stability of water electrolysis are greatly improved.

The preparation method of the non-noble metal water electrolysis anode material is characterized by comprising the following steps:

1) preparation of manganese oxide electrode:

preparing an electrolyte containing manganese salt, electrolyte and a pH buffering auxiliary agent, aging the electrolyte in a dark place at room temperature for 0.5-10 days, adding the electrolyte into an electrolytic cell, forming an electrode system by taking a conductive matrix as an anode, a saturated calomel electrode as a reference electrode and a graphite electrode, a platinum electrode or a carbon electrode as a cathode, carrying out electrolytic reaction in a steady deposition or dynamic deposition mode, and carrying out electrodeposition on the surface of the conductive matrix to generate manganese oxide so as to prepare a manganese oxide electrode;

2) loading of activating Components

Taking an aqueous solution of metal M salt as an impregnation solution, taking the manganese oxide electrode prepared in the step 1) as a carrier, and loading metal M ions on the manganese oxide electrode in an impregnation mode;

3) in situ generation of active layer

And (3) taking an alkaline electrolyte solution as an electrolyte, taking the manganese oxide electrode loaded with metal M ions in the step 2) as an anode, taking a graphite electrode, a platinum electrode or a carbon electrode as a cathode, and electrolyzing to generate the manganese oxide electrode loaded with the high-activity ultrathin activation layer MOOH in situ.

The preparation method of the non-noble metal electrolytic water anode material is characterized in that in the step 1), the conductive substrate is an FTO glass electrode, and the aging time is 4-8 days; the pH buffering auxiliary agent in the electrolyte in the step 1) is acetic acid, the electrolyte is sodium sulfate or sodium nitrate, and the manganese salt is manganese acetate.

The preparation method of the non-noble metal electrolytic water anode material is characterized in that in the electrolyte in the step 1), the mass concentration of acetic acid is 0.1-10%, preferably 0.5-3%, the concentration of sodium sulfate or sodium nitrate is 0.05-1mol/L, preferably 0.05-0.5mol/L, and the concentration of manganese acetate is 0.01-0.5mol/L, preferably 0.05-0.3 mol/L.

The preparation method of the non-noble metal electrolytic water anode material is characterized in that in the step 1), electrolytic reaction is carried out in a dynamic deposition mode, the potential of the electrokinetic potential deposition is-0.2-1.0V vs SCE, the cycle time is 1-50 times, preferably, the deposition potential is 0-0.8V vs SCE, and the cycle time is 5-20 times.

The preparation method of the non-noble metal electrolytic water anode material is characterized in that in the step 2), the metal M is one or more active elements of manganese, iron, cobalt, zinc, copper, niobium and tantalum, preferably one or more active elements of manganese, iron and cobalt;

the impregnation process in step 2) is as follows: firstly, immersing a manganese oxide electrode into a salt solution containing an active element, standing and immersing for a period of time, and then standing, immersing and washing for a period of time by deionized water to finish the cyclic loading of the active element; if the same or different active ingredients are loaded again, repeating the operations, and repeating the operations in the same way, and so on, and loading the ions of the active elements on the manganese oxide electrode; each active element is loaded for 1-5 times, preferably 1-2 times; wherein the concentration of the salt solution of each active element is 10-500mM, preferably 20-200 mM.

The preparation method of the non-noble metal electrolytic water anode material is characterized in that the metal M is two elements of iron and cobalt, impregnated Co ions are loaded on a manganese oxide electrode, and then impregnated Fe ions are loaded, and the specific process is as follows:

step a: immersing the manganese oxide electrode into a cobalt salt aqueous solution, standing and immersing for 10-3600s, taking out the manganese oxide electrode, immersing into deionized water, standing, immersing and washing for 10-3600s, and then taking out the manganese oxide electrode to finish the cyclic load of Co ions; repeating the process of loading the Co ions for 0-1 time again, so that the Co ions are circularly loaded on the manganese oxide electrode for 1-2 times in total;

step b: after the treatment in the step a is finished, immersing the Co ion-loaded manganese oxide electrode into an iron salt aqueous solution, standing and immersing for 10-3600s, taking out the electrode, immersing into deionized water, standing, immersing, washing for 10-3600s, and then taking out the electrode, namely completing the cyclic loading of Fe ions; repeating the process of loading Fe ions for 0-1 times again, so that the Fe ions are loaded on the manganese oxide electrode for 1-2 times in a circulating manner.

The preparation method of the non-noble metal electrolytic water anode material is characterized in that in the step a or the step b, the soaking time for loading Co ions or Fe ions is 60-300s, preferably 100-150 s; the soaking and water washing time is 60-300s, preferably 100-150 s; the concentration of the aqueous cobalt salt solution or the aqueous iron salt solution is 10 to 500mM, preferably 20 to 200 mM.

The preparation method of the non-noble metal water electrolysis anode material is characterized in that in the step 3), the alkaline electrolyte solution is a KOH or NaOH aqueous solution with the concentration of 0.5-1.5M; the voltage of electrolysis in the step 3) is 1.45-2.0V vs.

The non-noble metal electrolytic water anode material prepared by any one of the methods.

The non-noble metal water electrolysis anode material is applied to the preparation of hydrogen and oxygen by water electrolysis, and is characterized in that KOH or NaOH aqueous solution with the concentration of 0.5-1.5M is used as electrolyte, the non-noble metal water electrolysis anode material is used as an anode, and a graphite electrode, a platinum electrode or a carbon electrode is used as a cathode to perform electrolytic reaction to generate hydrogen and oxygen.

Compared with the prior art, the invention has the following beneficial effects:

the cost of the anode material for hydrogen production by electrolyzing water by noble metal is too high, the large-scale application is limited, and the search for the replaceable anode material for water electrolysis with low cost and excellent performance is an important direction for developing the universal application of the anode material. Generally speaking, the electrolyzed water non-noble metal anode has high overpotential, large energy consumption and poor stability, which are fundamental reasons restricting the development of the electrolyzed water anode, and how to improve the performance and the service life of the non-noble metal electrolyzed water anode is an important factor related to whether the electrolyzed water can be applied in a large scale. It is therefore important to develop a stable, reliable low-cost anode material. The solution of the invention is that manganese oxide is used as a catalytic substrate layer and an in-situ loaded active functional layer is additionally arranged. Firstly, the aged electrolyte and manganese oxide obtained after electrodeposition do not need high-temperature roasting, so that the problems of energy consumption and environmental pollution are reduced; secondly, active components are impregnated and loaded, and are selectively loaded on the surface with high energy and defects of the manganese oxide, so that the problems of low water electrolysis efficiency and instability of the manganese oxide caused by the defect part are effectively solved; thirdly, after testing, an ultrathin high-activity load activation layer (MOOH) is formed in situ under the action of electrochemistry, and the function layer remarkably improves the efficiency and stability of water electrolysis.

Drawings

FIG. 1 shows MnOx electrode, (MnO) in example 1_x，1C Co²⁺) Electrode and (MnO)_x，2C Co²⁺) Electrode and in example 2 (MnO)_x，2C Co²⁺，1C Fe³⁺) A comparison result graph of linear sweep voltammetry curves of an electrolytic water test of the electrode;

FIG. 2 shows MnOx electrode, (MnO) in example 3_x，1C Fe³⁺) Electrode and (MnO)_x，2C Fe³⁺) A comparison result graph of linear sweep voltammetry curves of an electrolytic water test of the electrode;

FIG. 3 is a graph comparing the current density with time under the steady state test in example 4;

FIG. 4 shows (MnO) in example 5_x，2C Co²⁺，1C Fe³⁺) A current density change relation curve graph along with time under the electrode steady state test;

FIG. 5 is a graph of the comparison of linear sweep voltammograms for the electrolyzed water test at different electrodes of example 6. (a) The method comprises the following steps MnOx; (b) MnOx,2C Co²⁺，1C Fe³⁺(ii) a (c) The method comprises the following steps Yang of curve (b)Transient tests are carried out on the electrodes after steady-state tests for 18 hours at a 0.7V vs SCE potential; (d) the method comprises the following steps Transient test was performed after dipping the anode electrode of curve (c) in 150mM ferric nitrate solution for 120s and washing with water for 120 s. The comparison of curve (c) and curve (b) in fig. 5 shows that the performance of the electrode is attenuated after 18h of electrolysis under the condition of 0.7V vs SCE, and the electrolyzed water performance of the electrode can be recovered by operating again in the way of curve (d), which is intended to show that when the electrode is tested under the harsh condition, although the performance of the electrode is attenuated, a specific operable method is provided for recovering the electrolyzed water performance of the electrode.

Detailed Description

The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention.

Example 1

Firstly, preparing a manganese oxide anode:

3.2g of sodium sulfate and 5.7g of manganese acetate are dissolved in 300ml of water, then acetic acid is added, the mass concentration of the acetic acid in the formed mixed solution is 2.5%, and the mixed solution is placed in a dark place and aged at room temperature for 8 days to obtain an electrolyte for later use.

An FTO glass electrode (rectangular electrode with effective area of 0.4 × 0.5 cm)²) Washing with ethanol, washing with 30% hydrogen peroxide, and ultrasonically cleaning with pure water to obtain anode.

Adding the aged electrolyte into an electrolytic cell, inserting the cleaned anode, forming an electrode system by using a saturated calomel electrode as a reference electrode and a platinum electrode as a cathode, performing electrolytic reaction in a dynamic deposition mode, wherein the potential of electrokinetic potential deposition is 0-0.8V vs SCE, and the cycle time is 11 times, after the deposition is finished, cleaning the electrolytic cell by using clean water, and placing the electrolytic cell at room temperature until the color of the electrode is changed into golden yellow to prepare MnO_xAnd an electrode.

Secondly, loading an active layer:

MnO prepared by the above method_xImmersing the electrode in 150mM cobalt nitrate aqueous solution, standing and immersing for 120s, taking out the electrode, immersing in deionized water, standing, immersing, washing for 120s, and taking out the electrode to finish the circulation of Co ionsRing loading, MnO to load Co ion in one cycle_xElectrode label (MnO)_x，1C Co²⁺) And an electrode.

The process of loading Co ions was repeated again 1 time, so that in MnO_xMnO for performing Co ion cyclic loading on electrode for 2 times in total and loading Co ions in two cycles_xElectrode label (MnO)_x，2C Co²⁺) And (5) electrodes and the like.

Thirdly, the method comprises the following steps: electrolytic test activation

MnO prepared by using 1M potassium hydroxide aqueous solution as electrolyte_xElectrode, (MnO)_x，1C Co²⁺) Electrode or (MnO)_x，2C Co²⁺) The electrode is used as an anode, the saturated calomel electrode is used as a reference electrode, the platinum electrode is used as a cathode to form an electrode testing system, the transient state of an electrode system is tested, an electrolytic water oxygen test experiment is carried out, the scanning rate of a linear scanning voltammetry is 50mV/s, in the electrolytic testing process, Co ions on the electrode are activated under the electrochemical action to form a metal Co hydroxyl compound activation layer, and the preparation of the activation function layer loaded manganese oxide electrode is completed.

MnOx electrode, (MnO) according to the test procedure described above_x，1C Co²⁺) Electrode and (MnO)_x，2C Co²⁺) The results of the comparison of the linear scanning voltammograms of the electrolyzed water test of the electrode are summarized in FIG. 1, as shown by the curves (a), (b), and (c) in FIG. 1, respectively. As can be seen from fig. 1: in terms of the performance of generating oxygen by electrolyzing water, the catalytic performance of the curve (b) is obviously improved compared with that of the curve (a), but the catalytic performance of the curve (c) is not obviously different from that of the curve (b), which shows that a very thin metal Co hydroxyl compound activation layer (CoOOH) loaded on the MnOx electrode can meet the good electrocatalytic effect.

Example 2:

firstly, preparing a manganese oxide anode:

MnO_xelectrode preparation procedure example 1 was repeated.

Secondly, loading an active layer:

mn prepared as described aboveO_xImmersing the electrode into 150mM cobalt nitrate aqueous solution, standing and immersing for 120s, then taking out the electrode, immersing into deionized water, standing, immersing, washing for 120s, and taking out the electrode; repeating the above operation once so that in MnO_xCo ion cycling load on the electrode was performed 2 times in total and was labeled (MnO)_x，2C Co²⁺) And an electrode.

Then adding (MnO) prepared above_x，2C Co²⁺) And immersing the electrode into 150mM ferric nitrate aqueous solution, standing and immersing for 120s, then taking out the electrode, immersing into deionized water, standing, immersing, washing for 120s, and taking out the electrode to finish the cyclic loading of the Fe ions. Thus, in MnO_xThe surface of the electrode is loaded with Co ions for 2 times and then Fe ions for one time, and the electrode is marked as (MnO)_x，2C Co²⁺，1C Fe³⁺) An electrode;

third, electrolytic test activation

(MnO) prepared above with 1M aqueous solution of potassium hydroxide as electrolyte_x，2C Co²⁺，1C Fe³⁺) The electrode is used as an anode, the saturated calomel electrode is used as a reference electrode, the platinum electrode is used as a cathode to form an electrode testing system, the transient state of an electrode system is tested, an electrolytic water oxygen test experiment is carried out, the scanning rate of a linear scanning voltammetry is 50mV/s, in the electrolytic testing process, Co ions on the electrode are activated under the electrochemical action to form a metal Co hydroxyl compound activation layer, and the preparation of the activation function layer loaded manganese oxide electrode is completed.

According to the test procedure described above, (MnO)_x，2C Co²⁺，1C Fe³⁺) The results of the linear scanning voltammogram comparison of the electrolyzed water test of the electrodes are summarized in FIG. 1, as shown by curve (d) in FIG. 1. As can be seen from fig. 1: in terms of the oxygen generation performance of the electrolyzed water, the catalytic performance of the curve (d) is obviously improved relative to that of the curve (c), which shows that the electrocatalytic performance of the electrolyzed water can be obviously improved by supporting hydroxyl oxide (MOOH) formed by CoFe on the MnOx electrode.

Example 3:

firstly, preparing a manganese oxide anode:

MnO_xelectrode preparation procedure example 1 was repeated.

Secondly, loading an active layer:

MnO prepared by the above method_xImmersing the electrode into 150mM ferric nitrate water solution, standing and immersing for 120s, taking out the electrode, immersing into deionized water, standing, immersing and washing for 120s, taking out the electrode, completing the cyclic load of the Fe ions, and performing the cyclic load of the MnO of the Fe ions_xElectrode label (MnO)_x，1C Fe³⁺) And an electrode. The process of loading Fe ions was repeated again 1 time so that in MnO_xMnO for carrying out Fe ion cyclic loading on the electrode for 2 times in total and carrying Fe ions in two cycles_xElectrode label (MnO)_x，2C Fe³⁺) Electrodes, and so on.

Third, electrolytic test activation

MnO prepared by using 1M potassium hydroxide aqueous solution as electrolyte_xElectrode, (MnO)_x，1C Fe³⁺) Electrode or (MnO)_x，2C Fe³⁺) The electrode is used as an anode, the saturated calomel electrode is used as a reference electrode, the platinum electrode is used as a cathode to form an electrode testing system, the transient state of an electrode system is tested, an electrolytic water oxygen test experiment is carried out, the scanning rate of a linear scanning voltammetry is 50mV/s, in the electrolytic testing process, Fe ions on the electrode are activated under the electrochemical action to form a metal Fe hydroxyl compound activation layer, and the preparation of the activation function layer loaded manganese oxide electrode is completed.

MnOx electrode, (MnO) according to the test procedure described above_x，1C Fe³⁺) Electrode and (MnO)_x，2C Fe³⁺) The results of the comparison of the linear scanning voltammograms of the electrolyzed water test of the electrode are summarized in FIG. 2, as shown by curve (a), curve (b), and curve (c) in FIG. 2, respectively. As can be seen from fig. 2: in terms of the oxygen production performance of electrolyzed water, the catalytic performance of the curve (b) is obviously improved compared with that of the curve (a), but the catalytic performance of the curve (c) is not obviously different from that of the curve (b), which shows that an ultrathin metal Fe hydroxyl compound activation layer (FeOOH) loaded on the MnOx electrode can meet the good electrocatalytic effect.

A comparison of the results of the experiments according to examples 1 to 3 shows that: the MnOx electrode is loaded with a hydroxyl iron oxide functional layer on the surface, so that the performance of improving the electrocatalytic activity of the electrode is optimal, and particularly, the electrocatalytic performance is more outstanding under the condition that the CoFe double-component forms hydroxyl oxide load.

Example 4:

firstly, preparing a manganese oxide anode:

MnO_xelectrode preparation procedure example 1 was repeated.

Secondly, loading an active layer:

MnO prepared by the above method_xImmersing the electrode into 150mM cobalt nitrate aqueous solution, standing and immersing for 120s, then taking out the electrode, immersing into deionized water, standing, immersing, washing for 120s, and taking out the electrode; repeating the above operation once so that in MnO_xCo ion cyclic loading was performed on the electrode for a total of 2 times and labeled as (MnO)_x，2C Co²⁺) And an electrode.

Then adding (MnO) prepared above_x，2C Co²⁺) And immersing the electrode into a 150mM ferric nitrate aqueous solution, standing and immersing for 120s, then taking out the electrode, immersing into deionized water, standing, immersing, washing for 120s, taking out the electrode, and repeating the operation once. Thus, in MnO_xThe surface of the electrode is loaded with Co ions for 2 times and then with Fe ions for 2 times, and the electrode is marked as (MnO)_x，2C Co²⁺，2C Fe³⁺) And an electrode.

Third, electrolyzed Water test

The method comprises the steps of taking 1M potassium hydroxide aqueous solution as electrolyte, inserting an anode electrode into the electrolyte, taking a saturated calomel electrode as a reference electrode, taking a platinum electrode as a cathode, connecting an external power supply of a testing device to form an electrode testing system, testing the steady state of an electrode system, carrying out an oxygen test experiment on electrolyzed water, and evaluating the performance and stability of the electrolyzed water of the electrode, wherein the external potential in the testing process is 0.64V vs SCE.

Continuously electrolyzing for 12h according to the above test procedure for water electrolysis, and when the anode electrode is MnO prepared in the first step of example 1_xElectrode, example 1 step two preparationOf (MnO)_x，2C Co²⁺) Electrode, prepared in step two of example 3 (MnO)_x，2C Fe³⁺) Electrode, and (MnO) prepared in step two of example 4_x，2C Co²⁺，2C Fe³⁺) The curves of the current density with time at the electrode are shown as a curve (a), a curve (b), a curve (c) and a curve (d) in fig. 3, respectively. As can be seen in fig. 3: no significant decay in current density was observed after 12 hours of steady state testing. However, the current density signal intensity of the curve (a) is the minimum, the current density signal intensities of the curves (b), (c) and (d) are all obviously improved, the anode electrodes corresponding to the curves (b), (c) and (d) all obviously improve the catalytic performance of the electrolyzed water, and the catalytic performance in MnO is improved_xThe active layer of metal hydroxide supported on the electrode can obviously improve the oxygen production effect of electrolyzed water, and the CoFe active component is soaked and electrochemically acted on MnO_xThe electrolytic water performance of the surface formed stable load activation functional layer is MnO_xThe electrolytic water performance is nearly 4 times.

Example 5:

for (MnO) prepared in step two of example 2_x，2C Co²⁺，1C Fe³⁺) The electrode is subjected to performance test, and the electrolytic water test process is as follows:

using 1M aqueous potassium hydroxide solution as electrolyte, and (MnO)_x，2C Co²⁺，1C Fe³⁺) The electrode is used as an anode, the saturated calomel electrode is used as a reference electrode, the platinum electrode is used as a cathode, the electrode is connected with an external power supply of a testing device to form an electrode testing system, the electrode system is tested in a stable state, an electrolytic water oxygen testing experiment is carried out, the external potential in the testing process is 0.7V vs SCE, and the electrolytic water performance and stability of the electrode are evaluated.

The electrolysis reaction was continued for 18h according to the above-mentioned electrolytic water test procedure, and the test results are shown in FIG. 4 (generally, the higher the voltage, the more vigorous the oxygen evolution, the higher the stability requirement of the electrode, and FIG. 4 uses a higher voltage than FIG. 3 to examine the electrode life). As can be seen from the steady state test of FIG. 4, under the high potential condition, the steady state test is not performed for 18 hoursObviously attenuated, the CoFe active component is soaked in MnO through electrochemical action_xA stable load activation functional layer is formed on the surface, and the performance of the electrolyzed water is improved.

Example 6

After 18 hours of steady state testing of example 5 at a potential of 0.7V vs SCE (MnO)_x，2C Co²⁺，1C Fe³⁺) Collecting the electrodes, and carrying out reactivation treatment, wherein the treatment process comprises the following steps: (MnO) after the steady state test_x，2C Co^{2 +}，1C Fe³⁺) Immersing the electrode into 150mM ferric nitrate water solution, standing and immersing for 120s, taking out the electrode, immersing into deionized water, standing, immersing and washing for 120s, and taking out the electrode to obtain the electrode after steady state test-activation treatment (MnO)_x，2C Co²⁺，1C Fe³⁺) And an electrode.

Activation by electrolytic test, the procedure is as follows:

A1M potassium hydroxide aqueous solution is used as an electrolyte, an anode electrode is inserted into the electrolyte, a saturated calomel electrode is used as a reference electrode, a platinum electrode is used as a cathode to form an electrode testing system, an electrode system is subjected to transient test, an oxygen test experiment is carried out on electrolyzed water, and the scanning rate of a linear scanning voltammetry method is 50 mV/s.

According to the above test procedure, MnO prepared in the first step of example 1 was used in the anodic electrolysis_xElectrode, prepared in step two of example 2 (MnO)_x，2C Co²⁺，1C Fe³⁺) Electrode, example 5 after 18 hours steady state testing at 0.7V vs SCE potential (MnO)_x，2C Co²⁺，1C Fe³⁺) Electrode, and Steady State test-after activation treatment (MnO) in example 6_x，2C Co²⁺，1C Fe³⁺) The results of the linear scanning voltammogram comparison of the electrolyzed water test at the electrode are summarized in FIG. 5, as shown by curve (a), curve (b), curve (c) and curve (d) in FIG. 1, respectively. As can be seen from fig. 5: as can be seen by comparing curve (b) and curve (c), example 2, step two, produced (MnO)_x，2C Co²⁺，1C Fe³⁺) The performance of the electrode has certain attenuation after 18 hours of testingAnd reducing, soaking the electrode in 150mM ferric nitrate solution for 120s again, washing the electrode with deionized water for 120s, and repairing the original performance attenuation, wherein the test result is shown as a curve (d) in figure 5, and the electrocatalytic performance exceeds a curve (b) in figure 5, thereby providing a powerful countermeasure for the attenuation of the service life of the electrode in the electrolytic process.

The statements in this specification merely set forth a list of implementations of the inventive concept and the scope of the present invention should not be construed as limited to the particular forms set forth in the examples.