阅读说明：本技术 一种CoSX@MnO2复合材料及其制备方法和应用 (CoSX@MnO2Composite material and preparation method and application thereof ) 是由 毛昌杰 石欣伟 陈京帅 陈永猛 于 2021-01-07 设计创作，主要内容包括：本发明提供了一种CoSX@MnO-2复合材料及其制备方法和应用,其制备方法包括：(1)MnO-2纳米管的制备；(2)ZIF-67@MnO-2复合材料的制备；(3)CoS-X@MnO-2催化剂的制备；本发明CoS-X@MnO-2催化剂的制备工艺步骤简单且可控,制备时间短,所得到的催化剂的结构为树枝状MnO-2贯穿果实状CoS-X,其结构稳定；另外,本发明制备的CoS-X@MnO-2催化剂在电催化析氧反应过程中,10mAcm～(-2)电流密度下的过电势仅有334mV,相比于商业的MnO-2催化剂470mV过电势下降136mV；另外,CoS-X@MnO-2的塔菲尔斜率为84.8mV dec～(-1),相对于商业的MnO-2得塔菲尔斜率140mV dec～(-1)有更小的塔菲尔斜率。这些均表明,CoS-X负载于载体ZIF-67@MnO-2上之后表现出的比商业MnO-2更优异的电催化性能。(The invention provides CoSX @ MnO 2 The composite material and the preparation method and the application thereof, wherein the preparation method comprises the following steps: (1) MnO 2 Preparing a nano tube; (2) ZIF-67@ MnO 2 Preparing a composite material; (3) CoS X @MnO 2 Preparing a catalyst; CoS of the invention X @MnO 2 The preparation process of the catalyst has simple and controllable steps and short preparation time, and the obtained catalyst has the structure of dendritic MnO 2 Fruit-through CoS X The structure is stable; in addition, CoS prepared by the invention X @MnO 2 The catalyst is 10mAcm in the electrocatalytic oxygen evolution reaction process ‑2 Overpotential at current density of only 334mV compared to commercial MnO 2 The overpotential of the catalyst is 470mV is reduced by 136 mV; in addition, CoS X @MnO 2 The Tafel slope of (1) was 84.8mV dec ‑1 With respect to commercial MnO 2 DetaffeSlope 140mV dec ‑1 With a smaller tafel slope. These all show that CoS X Supported carrier ZIF-67@ MnO 2 Specific commercial MnO exhibited after the above 2 More excellent electrocatalytic performance.)

1. CoS_X@MnO₂The preparation method of the catalyst is characterized by comprising the following steps:

(1)MnO₂preparing the nanotube: 0.2 to 0.5 part of KMnO by weight at room temperature₄Adding into 20-80 parts of deionized water, dispersing to form a uniform solution, and adding 5-15 parts of deionized water with the concentration of 1 mol. L^-1Hydrochloric acid solution was added to the KMnO₄In the solution, stirring and mixing uniformly, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 4-8 hours at the temperature of 120-180 ℃, centrifuging, washing and drying after the reaction is finished to obtain the MnO₂A nanotube;

(2)[email protected]₂preparing a composite material: firstly, MnO prepared in the step (1) is added₂Adding 0.02-0.08 part of nanotube into 15-45 parts of methanol for ultrasonic dispersion, quickly stirring uniformly, and then adding 0.2-0.8 part of Co (NO)₃)₂·6H₂Mixing O uniformly, quickly adding 10-30 parts of methanol solution of 2-methylimidazole, continuously stirring for reacting for 1-3h, and reactingCentrifuging, washing with methanol and drying to obtain the [email protected] MnO₂A composite material;

(3)CoS_X@MnO₂preparation of the catalyst: [email protected] MnO prepared in the step (2)₂Adding 0.02-0.08 part of composite material into 30-90 parts of absolute ethyl alcohol, uniformly dispersing by ultrasonic wave, transferring the obtained solution into a sealed glass bottle, adding 0.06-0.2 part of thioacetamide, carrying out reflux reaction at 70-120 ℃ for 1-5h, centrifuging, washing and drying after the reaction is finished, thus obtaining the CoS_X@MnO₂A catalyst.

2. The method according to claim 1, wherein the hydrochloric acid solution in the step (1) is added dropwise.

3. The preparation method according to claim 1, wherein the ultrasonic dispersion time in the step (2) is 30 to 60min, and the rapid stirring time is 30 to 60 min.

4. The method according to claim 1, wherein the 2-methylimidazole content in the methanol solution of 2-methylimidazole in the step (2) is 0.3 to 0.9 part.

5. The preparation method according to claim 1, wherein the washing in the step (1) and the washing in the step (3) are respectively carried out by using deionized water and absolute ethyl alcohol, and the drying is carried out for 8 hours in an electrothermal blowing dry box at 60 ℃.

6. CoS prepared according to the preparation method of claims 1-5_X@MnO₂The catalyst is characterized in that the morphology of the catalyst is dendritic MnO₂Fruit-through CoS_X。

7. The CoS of claim 6_X@MnO₂The application of the catalyst in electrocatalytic oxygen evolution reaction.

Technical Field

The invention relates to the technical field of new materials, in particular to CoSX @ MnO₂Composite material and its preparation method and application.

Background

Due to the increasing concern about energy crisis and environmental pollution, the search for renewable energy substitutes for fossil fuels is urgently needed, and therefore effective energy storage devices are explored, and among various innovative choices, the generation of hydrogen through electrolysis of water is exciting the intense research interest of people as an ideal clean energy source, and with the increase of energy demand and the understanding of environmental protection, the development of sustainable and clean resources has become one of the most popular problems in the current research, and due to the characteristics of wide and high-energy-efficiency raw materials and no harm to the environment, the electrochemical water decomposition (generation of hydrogen and oxygen) receives wide attention.

The electrochemical water splitting technology is widely considered to be one of the most attractive hydrogen and oxygen production technologies in the future due to simplicity, high energy conversion efficiency and wide application. However, water splitting is a thermodynamically unfavorable process, the overall efficiency of which is somewhat hindered due to the large potential of Hydrogen Evolution Reactions (HER) and Oxygen Evolution Reactions (OER) on most electrocatalyst materials. At present, Pt and IrO₂The most effective electrocatalysts for HER and OER, respectively, however, due to the high cost and scarcity of Pt and Ir materials, and their application in industrial scale water separation is not widespread, it is highly desirable to develop efficient, low cost electrocatalysts based on earth's abundant elements to completely decompose water.

The Oxygen Evolution Reaction (OER) is the most critical half-reaction in the water splitting process, however, as a critical half-reaction in the water splitting process, its efficiency is hampered by the multi-step proton-coupled electron transfer and slow kinetics processes. Has been widely used in combustion batteries and rechargeable metal batteries, noble metal catalysts such as iridium oxide (IrO)₂) And ruthenium oxide (RuO)₂) Since its superior electrocatalytic activity and stability are the most widely used commercial OER catalysts, however, scarcity and high cost severely limit its further development, which is the development of new high-performance, environmentally friendly and expensive catalystsThe trend of low price, material cost is inevitable for OER catalyst, in recent years, people have been working on developing non-noble metal catalyst, two-dimensional materials such as transition metal oxide, sulfide, phosphide and the like have wide application prospect in photo/electro catalytic decomposition water due to unique interlayer structure, wherein the two-dimensional materials comprise transition metal oxide, hydroxide, sulfide, phosphide and the like, and due to controllable structure, higher theoretical activity, environmental friendliness and low cost, the two-dimensional materials are extremely potential candidate materials, wherein manganese dioxide (MnO) is manganese dioxide (MnO)₂) Is a typical Transition Metal Oxide (TMOs), widely existing in the natural world and almost non-toxic, and has excellent electrical properties in catalytic activity as OER.

MnO₂Is a typical transition metal oxide, widely existing in nature and hardly toxic, usually MnO₂The activity of (A) is enhanced by increasing the amount of crystal water contained therein, which promotes the diffusion of protons in the solid phase, MnO₂With [ MnO ]₆]Octahedra being the stacking and linking state of the basic building blocks, and the conversion between Mn (III) and Mn (IV), MnO₂The electric activity of (A) is influenced by the crystal structure, form, surface state, etc. and multiple elements, MnO₂Has a composition of [ MnO₆]The tunnel structure composed of 2-by-2 arrangement has a one-dimensional state, resulting in a high specific surface area and more active sites that can be exposed, and thus has received extensive attention, but pure MnO₂Intrinsic conductivity is low and active sites are restricted, leading to high potential, slow thermodynamics and kinetics, MnO for enhanced electrical activity₂Designed into a composite conductive nano structure, can provide more active sites and shorter mass transfer paths.

As a novel hybrid material, Metal Organic Frameworks (MOFs) are built up by metal-containing units [ secondary building blocks (SBUs) ]]And organic ligands, forming a network structure and having excellent crystallinity, which can be widely used for gas trapping, sensing, drug delivery and electrochemistry due to the variability of metal units and organic ligands due to their special structures, and Zeolitic Imidazolate Frameworks (ZIFs) which are a class of structures having an extended three-dimensional structureThe structure is formed by connecting metal units through organic ligands, and is typically Co²⁺Coordinated MOFs, ZIFs-67, have been demonstrated to be ideal cobalt-based self-sacrificial templates, since cobalt-based sulfur compounds are currently considered promising catalysts, but cobalt-based materials respectively derived from ZIFs generally show low structure with stability and electrical conductivity due to their porous structure and agglomeration of metal units, and the main approach to solve the above problems is to combine ZIFs derivatives with electrical conductivity.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a CoS_X@MnO₂The composite material and the preparation method and the application thereof in oxygen evolution reaction, and the prepared composite material has excellent electrocatalytic performance and stability.

In order to achieve the purpose, the invention is realized by the following scheme:

CoS_X@MnO₂The preparation method of the catalyst comprises the following steps:

(1)MnO₂preparing the nanotube: 0.2 to 0.5 part of KMnO by weight at room temperature₄Adding into 20-80 parts of deionized water, dispersing to form a uniform solution, and adding 5-15 parts of deionized water with the concentration of 1 mol. L^-1Hydrochloric acid solution was added to the KMnO₄In the solution, stirring and mixing uniformly, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 4-8 hours at the temperature of 120-180 ℃, centrifuging, washing and drying after the reaction is finished to obtain the MnO₂A nanotube;

(2)[email protected]₂preparing a composite material: firstly, MnO prepared in the step (1) is added₂Adding 0.02-0.08 part of nanotube into 15-45 parts of methanol for ultrasonic dispersion, quickly stirring uniformly, and then adding 0.2-0.8 part of Co (NO)₃)₂·6H₂Mixing O uniformly, quickly adding 10-30 parts of methanol solution of 2-methylimidazole, continuously stirring for reacting for 1-3h, centrifuging after the reaction is finished, washing with methanol, and drying to obtain the [email protected] MnO₂A composite material;

(3)CoS_X@MnO₂catalyst and process for preparing sameThe preparation of (1): [email protected] MnO prepared in the step (2)₂Adding 0.02-0.08 part of composite material into 30-90 parts of absolute ethyl alcohol, uniformly dispersing by ultrasonic wave, transferring the obtained solution into a sealed glass bottle, adding 0.06-0.2 part of Thioacetamide (TAA), carrying out reflux reaction at 70-120 ℃ for 1-5h, centrifuging, washing and drying after the reaction is finished, thus obtaining the CoS_X@MnO₂A catalyst.

Preferably, the hydrochloric acid solution in the step (1) is added dropwise.

Preferably, the ultrasonic dispersion time in the step (2) is 30-60min, and the rapid stirring time is 30-60 min.

Preferably, the content of 2-methylimidazole in the methanol solution of 2-methylimidazole in step (2) is 0.3-0.9 part.

Preferably, in the step (1) and the step (3), deionized water and absolute ethyl alcohol are respectively used for washing, and the drying is carried out in an electrothermal blowing drying oven at 60 ℃ for 8 hours.

In addition, the invention also claims CoS prepared by the preparation method_X@MnO₂A catalyst in the form of dendritic MnO₂Fruit-through CoS_X。

The invention also protects the CoS_X@MnO₂The application of the catalyst in electrocatalytic oxygen evolution reaction.

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

(1) CoS of the invention_X@MnO₂The preparation process of the catalyst has simple and controllable steps and short preparation time, and the obtained catalyst has the structure of dendritic MnO₂Fruit-through CoS_XIts structure is stable.

(2) The invention uses [email protected] MnO₂The composite material as a carrier can greatly improve CoS_XThe loading effect on the surface and inside of the carrier is improved, and CoS is improved_XThe utilization rate of the catalyst is effectively improved.

(3) The invention is [email protected] MnO₂The shape of the zinc oxide is uniformly surrounded in branched MnO by a fruit-shaped ZIF-67 polyhedron₂MnO is greatly improved around the nano tube₂While greatly reducing MnO₂The overall activity of the catalyst is improved.

(4) Novel CoS prepared by the invention_X@MnO₂The catalyst is 10mAcm in the electrocatalytic oxygen evolution reaction process^-2Overpotential at current density of only 334mV compared to commercial MnO₂The overpotential of the catalyst is 470mV is reduced by 136 mV; in addition, CoS_X@MnO₂The Tafel slope of (1) was 84.8mV dec^-1With respect to commercial MnO₂To obtain the Tafel slope of 140mV dec^-1With a smaller tafel slope. These all show that CoS_XSupported carrier [email protected] MnO₂Specific commercial MnO exhibited after the above₂More excellent electrocatalytic performance.

(5) For composite materials and MnO under the same conditions₂To further study OER kinetics, semi-circle diameter is used to indicate charge transfer resistance, and the corresponding Nyquist plot shows CoSx @ MnO₂(Rct ═ 12.72 Ω) active charge transfer ratio MnO2(Rct ═ 172.48 Ω), and the results showed that the composite structure significantly improved catalytic activity, which can be attributed to the ambitious structure of the composite structure and the Co-based compound and MnO₂The synergistic effect of (A) and (B).

(6) CoS prepared by the invention_X@MnO₂Has faster reaction kinetics, and moreover, CoS_X@MnO₂Stability and MnO₂Compared with the prior art, the method is also obviously improved, and can stably catalyze the water electrolysis for 12h without obvious reduction.

Drawings

FIG. 1 shows MnO prepared in example 1 of the present invention₂TEM image of nanotubes, showing MnO₂The topographical features of (1).

FIG. 2 is a [email protected] MnO prepared in example 1 of the present invention₂TEM image of the composite material, showing [email protected] MnO₂The topographical features of (1).

FIG. 3 is a CoS prepared according to example 1 of the present invention_X@MnO₂TEM image of the catalyst, showing CoS_X@MnO₂The topographical features of (1).

FIG. 4 is a CoS prepared according to example 1 of the present invention_X@MnO₂The LSV polarization curve chart of the catalyst used for electrocatalytic oxygen evolution reaction shows the catalytic activity of the catalyst.

FIG. 5 is a CoS prepared according to example 1 of the present invention_X@MnO₂The tafel slope curve chart of the catalyst used for electrocatalytic oxygen evolution reaction shows the mass transfer efficiency of the catalyst.

FIG. 6 is a CoS prepared according to example 1 of the present invention_X@MnO₂The electrochemical impedance spectrogram of the catalyst used for the electrocatalytic oxygen evolution reaction shows the electron transfer efficiency of the catalyst.

FIG. 7 is a CoS prepared according to example 1 of the present invention_X@MnO₂The stability test chart of the catalyst used for the electrocatalytic oxygen evolution reaction shows the stability of the catalyst.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

CoS_X@MnO₂The preparation method of the catalyst comprises the following steps:

(1)MnO₂preparing the nanotube: 0.3160g of KMnO were added at room temperature₄Adding into 30mL deionized water, dispersing to obtain uniform solution, and adding 10mL of 1 mol.L^-1Hydrochloric acid solution was added to the KMnO₄Stirring and mixing the solution uniformly, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 5 hours at 160 ℃, centrifuging after the reaction is finished, washing the solution for 3 times by using deionized water and absolute ethyl alcohol respectively, and drying the solution in an electrothermal blowing drying oven at 60 ℃ for 8 hours to obtain the MnO₂A nanotube;

(2)[email protected]₂preparing a composite material: firstly, MnO prepared in the step (1) is added₂Nanotube 0.050Adding 0g of the mixture into 25mL of methanol, performing ultrasonic dispersion for 30min, rapidly magnetically stirring at room temperature for 30min, and adding 0.4000g of Co (NO)₃)₂·6H₂O is mixed well and then 15mL CH containing 0.4150g 2-methylimidazole are added rapidly₃Continuously stirring the OH solution for reaction for 2 hours, centrifuging after the reaction is finished, washing the solution for 3 times by using methanol, and drying the solution in an electrothermal blowing drying oven at the temperature of 60 ℃ for 8 hours to obtain the [email protected] MnO₂A composite material;

(3)CoS_X@MnO₂preparation of the catalyst: [email protected] MnO prepared in the step (2)₂Adding 0.0400g of composite material into 60mL of absolute ethyl alcohol, carrying out ultrasonic dispersion for 30min, transferring the obtained solution into a sealed glass bottle, adding 0.1200g of TAA, carrying out reflux reaction at 90 ℃ for 2h, centrifuging after the reaction is finished, washing with deionized water and absolute ethyl alcohol for 3 times respectively, and drying in a 60 ℃ oven for 8h to obtain the CoS_X@MnO₂A catalyst.

Example 2

CoS_X@MnO₂The preparation method of the catalyst comprises the following steps:

(1)MnO₂preparing the nanotube: 0.5120g of KMnO were added at room temperature₄Adding into 50mL deionized water, dispersing to obtain a uniform solution, and adding 12mL of 1moL L^-1Hydrochloric acid solution was added to the KMnO₄Stirring and mixing the solution uniformly, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 5 hours at 160 ℃, centrifuging after the reaction is finished, washing the solution for 3 times by using deionized water and absolute ethyl alcohol respectively, and drying the solution in an electrothermal blowing drying oven at 60 ℃ for 8 hours to obtain the MnO₂A nanotube;

(2)[email protected]₂preparing a composite material: firstly, MnO prepared in the step (1) is added₂Adding 0.0800g of nanotube into 30mL of methanol, ultrasonically dispersing for 45min, rapidly magnetically stirring at room temperature for 30min, and adding 0.6000g of Co (NO)₃)₂·6H₂O is mixed well and then 20mL CH containing 0.5560g 2-methylimidazole are added rapidly₃Continuously stirring OH solution, reacting for 2 hr, centrifuging after reaction, washing with methanol for 3 times, and drying at 60 deg.C in electrothermal blowing dry box for 8 hr to obtain final productThe [email protected] MnO₂A composite material;

(3)CoS_X@MnO₂preparation of the catalyst: [email protected] MnO prepared in the step (2)₂Adding 0.0500g of composite material into 70mL of absolute ethyl alcohol, carrying out ultrasonic dispersion for 45min, transferring the obtained solution into a sealed glass bottle, adding 0.1500g of TAA, carrying out reflux reaction for 2h at 90 ℃, centrifuging after the reaction is finished, washing for 3 times by using deionized water and absolute ethyl alcohol respectively, drying in a 60 ℃ oven for 8h, and obtaining the CoS_X@MnO₂A catalyst.

Example 3

CoS_X@MnO₂The preparation method of the catalyst comprises the following steps:

(1)MnO₂preparing the nanotube: 0.8310g of KMnO in parts by weight at room temperature₄Adding into 60mL deionized water, dispersing to obtain uniform solution, and adding 15mL of 1moL L^-1Hydrochloric acid solution was added to the KMnO₄Stirring and mixing the solution uniformly, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 5 hours at 160 ℃, centrifuging after the reaction is finished, washing the solution for 3 times by using deionized water and absolute ethyl alcohol respectively, and drying the solution in an electrothermal blowing drying oven at 60 ℃ for 8 hours to obtain the MnO₂A nanotube;

(2)[email protected]₂preparing a composite material: firstly, MnO prepared in the step (1) is added₂Adding 0.0900g of nanotube into 35mL of methanol, ultrasonically dispersing for 30min, rapidly magnetically stirring at room temperature for 30min, and adding 0.8000g of Co (NO)₃)₂·6H₂O is mixed well and 30mL CH containing 0.8750g 2-methylimidazole are added rapidly₃Continuously stirring the OH solution for reaction for 2 hours, centrifuging after the reaction is finished, washing the solution for 3 times by using methanol, and drying the solution in an electrothermal blowing drying oven at the temperature of 60 ℃ for 8 hours to obtain the [email protected] MnO₂A composite material;

(3)CoS_X@MnO₂preparation of the catalyst: [email protected] MnO prepared in the step (2)₂Adding 0.1000g of the composite material into 80mL of absolute ethyl alcohol, ultrasonically dispersing for 45min, transferring the obtained solution into a sealed glass bottle, adding 0.2000g of TAA, and heating at 90 DEG CCarrying out reflux reaction for 2h, centrifuging after the reaction is finished, washing for 3 times by using deionized water and absolute ethyl alcohol respectively, and drying in an oven at 60 ℃ for 8h to obtain the CoS_X@MnO₂A catalyst.

Example 4

CoS_X@MnO₂The preparation method of the catalyst comprises the following steps:

(1)MnO₂preparing the nanotube: 1.2060g of KMnO in parts by weight at room temperature₄Adding into 80mL deionized water, dispersing to obtain a uniform solution, and adding 18mL of 1moL L^-1Hydrochloric acid solution was added to the KMnO₄Stirring and mixing the solution uniformly, transferring the mixed solution into a hydrothermal reaction kettle, reacting for 5 hours at 160 ℃, centrifuging after the reaction is finished, washing the solution for 3 times by using deionized water and absolute ethyl alcohol respectively, and drying the solution in an electrothermal blowing drying oven at 60 ℃ for 8 hours to obtain the MnO₂A nanotube;

(2)[email protected]₂preparing a composite material: firstly, MnO prepared in the step (1) is added₂Adding 0.1200g of nanotube into 45mL of methanol, ultrasonically dispersing for 45min, rapidly magnetically stirring at room temperature for 30min, and adding 0.8500g of Co (NO)₃)₂·6H₂O is mixed well and 30mL CH containing 0.9180g 2-methylimidazole are added rapidly₃Continuously stirring the OH solution for reaction for 2 hours, centrifuging after the reaction is finished, washing the solution for 3 times by using methanol, and drying the solution in an electrothermal blowing drying oven at the temperature of 60 ℃ for 8 hours to obtain the [email protected] MnO₂A composite material;

(3)CoS_X@MnO₂preparation of the catalyst: [email protected] MnO prepared in the step (2)₂Adding 0.1200g of composite material into 90mL of absolute ethyl alcohol, performing ultrasonic dispersion for 45min, transferring the obtained solution into a sealed glass bottle, adding 0.2000g of TAA, performing reflux reaction at 90 ℃ for 2h, centrifuging after the reaction is finished, washing with deionized water and absolute ethyl alcohol for 3 times respectively, and drying in a 60 ℃ oven for 8h to obtain the CoS_X@MnO₂A catalyst.

CoS prepared in example 1_X@MnO₂The catalyst material is subjected to performance evaluation, and specifically comprises the following steps:

(1)CoS_X@MnO₂preparing an electrode:

to prepare the electrode paste, 5mg CoS was added_X@MnO₂The catalyst, 40mL Naifon, 960mL of solvent (1: 1v/v water/ethanol) were mixed together and then sonicated for 30min to form a dispersion, 40mL of the dispersion was dropped onto the CFP, then dried at 60 ℃ for 12 h.

(2)CoS_X@MnO₂Application in electrocatalytic oxygen evolution reaction:

OER performance was evaluated on an electrochemical workstation (CHI 660E, CH apparatus) at room temperature in 1M aqueous KOH using a three-electrode system with a supported CoS with a geometric area of 5mm by 5mm_X@MnO₂Carbon Fiber Paper (CFP), platinum sheet (1cm multiplied by 1cm) and saturated calomel reference electrode of the catalyst are respectively used as a working electrode, a contrast electrode and a reference electrode to form a three-electrode system, and CoS is prepared by linear scanning voltammetry_X@MnO₂The catalyst is subjected to electrochemical oxygen evolution performance test and commercial MnO is selected₂And (5) carrying out comparison test.

The Linear Sweep Voltammetry test in this example uses the LSV-Linear Sweep Voltammetry technology, the electrolyte is a 1M KOH solution, the Sweep range is vs RHE, and the Sweep speed is 5 mV/s. And further converting the LSV curve into a Tafel slope curve through a Tafel formula to obtain an oxygen evolution kinetic parameter.

(3)CoS_X@MnO₂Stability testing of the catalyst:

in order to investigate whether the catalyst of the present invention has long-term stable catalytic activity, the prepared catalyst was evaluated for stability using cyclic voltammetry and electrochemical impedance in a 1M KOH solution.

As a result of measurement, CoS was obtained in example 1_X@MnO₂Catalyst at 10mA cm^-2The over-potential under the current density is only 334mV, and the Tafel slope is 84.8mV dec^-1Electrochemical impedance measured resistance of 12.72 Ω, CoS_X@MnO₂Stability and MnO₂Compared with the prior art, the method is also obviously improved, and can stably catalyze water electrolysisThere was no significant drop in 12 h.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.