CN115261885A

CN115261885A - RuSe2Preparation of/Co-N-C nano composite material and hydrogen evolution application thereof under alkaline condition

Info

Publication number: CN115261885A
Application number: CN202210826322.6A
Authority: CN
Inventors: 马江权; 史明豪; 李楠; 詹伟; 霍兰兰; 朱斌; 黄良琪; 董迁
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2022-07-04
Filing date: 2022-07-04
Publication date: 2022-11-01

Abstract

RuSe₂Preparation of/Co-N-C nano composite material and hydrogen evolution application thereof under alkaline condition. The invention belongs to the field of electrocatalytic preparation and application, and particularly relates to RuSe₂Preparation of/Co-N-C nano composite material and application thereof in electrocatalytic hydrogen evolution. The preparation method comprises the steps of firstly preparing a white crystalline Co and N doped carbon nanosheet precursor through a solid pyrolysis method, then synthesizing the Co-N-C nanosheet through high-temperature annealing in a tube furnace, and then carrying out a hydrothermal method on RuSe₂Uniformly growing on Co-N-C nano-sheets, and finally annealing in a tube furnace to obtain RuSe₂a/Co-N-C nanocomposite. Benefit from Co functionalization and unique heterogeneitySynergistic effect of interface initiation, ruSe₂the/Co-N-C heterostructure electrocatalyst has good Hydrogen Evolution (HER) performance in alkalinity. Synthetic RuSe₂the/Co-N-C heterostructure electrocatalyst has the advantages of simple synthesis operation, environmental friendliness, no pollution and the like, and has excellent HER activity and stability.

Description

RuSe2Preparation of/Co-N-C nano composite material and hydrogen evolution application thereof under alkaline condition

Technical Field

The invention belongs to the field of preparation and application of electrocatalysts, and particularly relates to RuSe₂Preparation and application of/Co-N-C nano composite material.

Background

The energy crisis is hindering the socioeconomic development of this world, and the development of clean energy is urgently needed. Hydrogen (H)₂) Is considered a potential clean energy source due to its high energy density and low environmental pollution. The electrocatalytic hydrogen evolution is high-efficiency and green H₂A production technology. Although the electrocatalyst based on noble metal Pt can realize stable, high-efficiency and continuous H₂However, it is not suitable for wide application because of its high cost and scarce supply. Therefore, the development of a novel non-noble metal electrocatalyst which can replace Pt with high efficiency and low cost is urgent.

Although Ru is also a rare element of a transition metal, the price of Ru is less than one fourth of that of Pt, and the Ru metal per se has good catalytic activity and catalytic stability. Numerous studies have shown that Ru can be combined with group VA or group VIA non-metallic elements into an effective electrocatalyst, which can have Pt-like hydrogen bonding strength and exhibit good HER activity and corrosion resistance. Rus has been shown₂、RuSe₂And RuTe₂TMDCs is an excellent class of HER electrocatalysts.

At the same time, too slow a water molecule adsorption and dissociation step (Volmer step) is the main reason for poor basic HER kinetics. After the Volmer step, the adsorbed hydrogen atom (H)_ad) Recombination to H₂And then desorbed from the electrocatalyst. H₂O、OH_adAnd H_adAre the basic inverse ofThe individual intermediates in question, and essentially the ideal catalyst, should have a balanced adsorption capacity for each reaction intermediate to achieve rapid HER kinetics in alkaline media. It is a reasonable design strategy to construct heterostructured electrocatalysts to trigger synergistic effects at the heterointerface to enhance basic HER kinetics. In particular, one component of the heterostructure acts as a water dissociation promoter, while the other part is responsible for the subsequent HER process. Carbon-based materials have the marked advantage of high electrical conductivity and have been widely used as electrocatalyst supports. However, they themselves have little decomposition H₂O and therefore cannot be used as a catalyst promoter for basic HER. It would therefore be of great importance to impart good electrical conductivity to carbonaceous materials to accelerate the Volmer step to develop efficient heterostructure electrocatalysts for alkaline HER.

In the invention, a transition metal functionalization strategy is provided, and the synthesis of a multifunctional carbon nanosheet is used as an electrocatalyst carrier of an alkaline HER. Specifically, atomically dispersed Co species are confined to N-doped carbon nanoplatelets (Co-N-C) to impart additional water adsorption and desorption functions to the carbon nanoplatelets. Doping of N destroys the electronic neutrality of carbon and induces polarization of adjacent carbon atoms to promote H₂And (4) activating the molecules. Obtained RuSe₂the/Co-N-C composite material has excellent HER performance and stability under alkaline conditions.

Disclosure of Invention

The invention aims to provide RuSe₂the/Co-N-C composite material and the preparation method thereof are applied to the preparation of hydrogen by electrolyzing water under the alkaline condition, and have excellent HER performance and stability.

The technical scheme of the invention is as follows: the invention provides a RuSe₂The catalyst is prepared by multi-step synthesis of RuSe₂Firstly, preparing a white crystalline Co and N doped carbon nanosheet precursor through a solid pyrolysis method, synthesizing Co-N-C nanosheets through high-temperature annealing in a tubular furnace, and then synthesizing RuSe through a hydrothermal method₂Uniformly growing on Co-N-C nano-chips, and finally annealing in a tube furnace to obtain the catalystRuSe₂a/Co-N-C nanocomposite.

The specific process comprises the following steps:

(1) And synthesizing the Co and N doped carbon nanosheets by a solid pyrolysis method. Specifically, a certain amount of cobalt (II) acetylacetonate is taken as a cobalt source, dissolved together with urea and glucose into a beaker filled with deionized water, and subjected to ultrasonic treatment and stirring for 120min at room temperature to obtain a pink transparent uniform solution. Wherein the mass ratio of cobalt acetylacetonate (II) to urea is 1: 150-200, wherein the mass ratio of cobalt (II) acetylacetonate to glucose is 1:10 to 15.

According to the invention, the better cobalt-nitrogen doped carbon nanosheet can be obtained only by selecting glucose as a carbon source, cobalt acetylacetonate as a cobalt source and urea as a nitrogen source. If the carbon source, the cobalt source and the nitrogen source are replaced by other components, the appearance of the cobalt-nitrogen doped carbon nanosheet is influenced, and the electro-catalysis performance is influenced. Meanwhile, the thickness of the carbon nano-sheet prepared from different raw materials, the element proportion and the element distribution of cobalt and nitrogen are different, and the thickness and the element distribution are important factors influencing the activity of the catalyst.

Preferably, the method comprises the following steps: the mass ratio of cobalt (II) acetylacetonate to urea is 1:160, the mass ratio of cobalt (II) acetylacetonate to glucose is 1:10.

(2) Placing the open beaker in a forced air drying oven, completely evaporating pink solution to obtain white crystalline precursor, loading with a crucible, transferring into a tube furnace, and introducing N₂Fermenting at 5 deg.C for 5 min as protective gas^-1Heating to 900 deg.C at a heating rate, keeping the temperature for calcining for 5h, and introducing N after calcining₂Naturally cooling to room temperature, and collecting black solid to obtain the Co-N-C nanosheet. Wherein the drying temperature of the air drying oven is 70-90 ℃.

Preferably, the method comprises the following steps: the drying temperature of the forced air drying oven was 80 ℃.

The calcination temperature can affect the graphitization degree of the carbon nanosheets and the combination degree of the simple substance cobalt, and the temperature lower than 900 ℃ is not beneficial to the formation of the simple substance cobalt and the carbon nanosheets with high graphitization degree.

The Co-N-C nanosheets prepared by the inventionHas good appearance structure and is beneficial to later-stage RuSe loading₂The particles can enable the combination of RuSe2 particles and Co-N-C nanosheets to be tighter, and are beneficial to the formation and exposure of more heterojunctions, so that the catalytic activity is improved.

(3) Preparation of Fresh RuSe by hydrothermal method₂Specifically, a certain amount of Co-N-C is respectively dissolved in deionized water, and after 120min ultrasonic vigorous stirring (ultrasonic treatment is carried out under an ultrasonic machine with 220w power), se powder and RuCl are mixed₃Adding the mixture into the solution, stirring vigorously for 10min, then adding 2mL of hydrazine hydrate (Se powder: 15 mg of hydrazine hydrate). Wherein, se powder and RuCl₃The mass ratio of (1): 5-6, the mass ratio of the Se powder to the Co-N-C is 1.2-1.6, and the mass ratio of the Se powder to the Co-N-C is preferably 1.

(4) The product of the previous step, fresh RuSe₂Thermal annealing treatment of/Co-N-C in a tube furnace to produce RuSe₂a/Co-N-C nanocomposite, in particular Fresh Ruse₂the/Co-N-C is loaded in a crucible and placed in a tube furnace, and N is introduced₂As shielding gas, at 5 deg.C for min^-1Heating to the set temperature at the heating rate, keeping the temperature for 2 hours, and naturally cooling to the room temperature to obtain the final product RuSe₂and/Co-N-C. Wherein the calcining temperature is 300-500 ℃.

Preferably, the method comprises the following steps: the calcination temperature was 400 ℃.

The invention synthesizes RuSe by multiple steps₂Firstly, preparing a white crystalline Co and N doped carbon nanosheet precursor through a solid pyrolysis method, synthesizing Co-N-C nanosheets through high-temperature annealing in a tubular furnace, and then synthesizing RuSe through a hydrothermal method₂Uniformly growing on Co-N-C nano-sheets, and finally obtaining RuSe by annealing in a tube furnace₂/Co-N-C nanocompositeAnd (5) synthesizing the materials. The invention optimizes RuSe₂And different mass ratios of Co-N-C to obtain the optimal preparation conditions, and finally obtaining the RuSe₂the/Co-N-C nano composite material is applied to electrolyzing water and hydrogen evolution under an alkaline environment.

RuSe₂The application of the/Co-N-C nano composite material in the electrocatalytic hydrogen evolution performance test method uses a three-electrode system, and a working electrode is loaded with RuSe₂The glassy carbon electrode of the/Co-N-C nano composite material is a graphite rod electrode, the reference electrode is an Hg/HgO electrode, and the electrolyte is 1mol/L KOH solution.

The invention has the technical effects that:

(1) Preparing Co-N-C nanosheets with wrinkled appearances and a large number of active sites by a solid pyrolysis method.

(2) First hydrothermal reaction of RuSe₂Uniformly loaded on the surface of the Co-N-C nanosheet to prepare RuSe₂a/Co-N-C nanocomposite.

(3) The amount of Co-N-C added to RuSe was investigated₂Influence of electrocatalytic HER Performance of/Co-N-C nanocomposites. RuSe₂And Co-N-C is favorable for improving the electrocatalytic performance.

(4) Prepared RuSe₂the/Co-N-C-5 has more excellent electrocatalytic HER performance and stability in alkaline solution.

Drawings

FIG. 1 is an SEM photograph of example 1.

FIG. 2 is an XRD pattern for example 1, example 2, example 3, example 4, comparative example 1, comparative example 2, comparative example 3 and comparative example 4.

FIG. 3 is a plot of the polarization of electrolyzed water HER in 1.0M KOH solutions for examples 1, 2, 3, and 4.

FIG. 4 is a plot of the polarization of electrolyzed water HER in 1.0M KOH solution for example 1, comparative example 2, comparative example 3, and comparative example 4.

FIG. 5 is a Tafel plot of electrolyzed water HER in 1.0M KOH solutions of examples 1, 2, 3, and 4.

FIG. 6 is a Tafel plot of example 1, comparative example 2, comparative example 3, and comparative example 4 for the electrolysis of water HER in 1.0M KOH solution.

FIG. 7 is a current time curve for electrolyzing water at an overpotential of 26mV for 17 hours in example 1.

Detailed Description

The present invention is further illustrated by the following examples, but the scope of the present invention is not limited to the following examples.

Example 1

Preparation of 1.1mol/L KOH solution

5.62g of KOH was dissolved in 50mL of ultrapure water, and after the KOH solution was completely dissolved and cooled, the volume was determined in a 100mL volumetric flask.

Preparation of Co and N doped carbon nanosheets

(1) And synthesizing the Co and N doped carbon nanosheets by a solid pyrolysis method. Specifically, 0.05g of cobalt (II) acetylacetonate as a cobalt source was added to 40mL of deionized water together with 8.0g of urea and 0.50g of glucose, and the mixture was subjected to ultrasonic treatment at room temperature and stirred for 120 minutes to obtain a pink transparent uniform solution.

(2) Placing the open beaker in a forced air drying oven, setting the temperature at 80 deg.C, completely evaporating pink solution to obtain white crystalline precursor, placing in a crucible, transferring into a tube furnace, and introducing N₂Fermenting at 5 deg.C for 5 min as protective gas^-1Heating to 900 deg.C at a heating rate, keeping the temperature for calcining for 5h, and introducing N after calcining₂Naturally cooling to room temperature, and collecting black solid to obtain the Co-N-C nanosheet.

3.Fresh RuSe₂Co-N-C nanocomposites

Preparation of Fresh Ruse by hydrothermal method₂Specifically, 5mg of Co-N-C are respectively dissolved in 35ml of deionized water, and after 120min of ultrasonic vigorous stirring, 0.0098g of Se powder and 0.0518g of RuCl are mixed₃Adding into the above solution, stirring vigorously for 10min, adding 2ml hydrazine hydrate, using 50ml autoclave with Teflon lining as reaction vessel, addingTransferring the obtained solution into a forced air drying oven, heating to 120 ℃ and keeping for 12 hours, naturally cooling the reaction kettle to room temperature after the reaction is finished, pouring out the liquid, centrifugally collecting the precipitate, continuously washing with deionized water and ethanol for 5 to 8 times, and finally drying in a vacuum drying oven at 60 ℃ overnight.

4.RuSe₂Preparation of/Co-N-C nano composite material

The product of the previous step, fresh RuSe₂Thermal annealing treatment of/Co-N-C in a tube furnace to produce RuSe₂a/Co-N-C nanocomposite, in particular Fresh Ruse₂the/Co-N-C is loaded in a crucible and arranged in a tube furnace, and N is introduced₂As shielding gas, at 5 deg.C for min^-1Heating to 400 ℃ at a heating rate, keeping the temperature for 2 hours, and naturally cooling to room temperature to obtain a final product RuSe₂/Co-N-C。

Applications of

1. Activation treatment of electrocatalyst

(1) Catalyst ink was prepared by dispersing 2mg of the catalyst and 10. Mu.L of 5wt% Nafion in a mixed solution containing 375. Mu.L of ultrapure water and 125. Mu.L of ethanol. After continuing the ultrasonic treatment for 20 minutes, 5. Mu.L of a uniform ink was dropped on a previously polished glassy carbon electrode having a diameter of 3mm, followed by natural drying at room temperature.

(2) A three-electrode system is used, wherein the working electrode is a glassy carbon electrode the surface of which is dropwise coated with the electrode in the embodiment 1, the counter electrode is a graphite rod electrode, the reference electrode is an Hg/HgO electrode, and the electrolyte is 1mol/L KOH;

(3) Cyclic Voltammetry (CV) activation: the Shanghai Chenghua DH7000 electrochemical workstation is used, a CV program is adopted, the test interval is-0.8 to-1.6V vs. RHE, the sweep rate is 100mV/s, the electrode is circulated for 20 circles, and the electrode reaches a stable state.

2. Linear Sweep Voltammetry (LSV) testing

After activation, the switching program is a linear sweep voltammetry program, the test interval is-0.8 to-1.6V vs. RHE, the sweep rate is 5mV/s, and the electrocatalyst is at-10 mA/cm in alkaline electrolyte²The overpotential was 26mV, as shown in FIG. 3.

3. Stability test

After activation, the switching program was a chronoamperometry program with a voltage setting of 26mv and a time setting of 61200s. As shown in fig. 7, the voltage variation of the electrocatalyst is not large, demonstrating its good stability.

SEM image prepared in example 1 synthetic RuSe is shown in FIG. 1₂the/Co-N-C nano composite material has regular appearance. XRD pattern as shown in FIG. 2, ruSe obtained after high temperature annealing at 400 deg.C₂The sample of/Co-N-C has better crystallinity, and all diffraction peaks are similar to the crystalline RuSe₂Matching, while the broad peak at 25.5 ° and the sharp diffraction peak at 44.1 ° attributed to metallic Co were also well matched, demonstrating RuSe₂Successful synthesis of/Co-N-C nanocomposites.

Example 2

Compared with example 1, the difference is that: the amount of Co-N-C was changed to 0.002g in the preparation process, and the other preparation methods were the same as in example 1.

The application method is the same as that of RuSe prepared in example 1 and example 2₂the/Co-N-C nano composite material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the catalyst is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the current density of 10mA/cm²The overpotential was 68mV.

Example 3

Compared with example 1, the difference is that: the amount of Co-N-C was changed to 0.01g in the preparation process, and the other preparation methods were the same as in example 1.

The application method is the same as that of RuSe prepared in example 1 and example 3₂the/Co-N-C nano composite material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the catalyst is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the current density of 10mA/cm²The overpotential was 59mV.

Example 4

Compared with example 1, the difference is that: the amount of Co-N-C was changed to 0.015g in the preparation process, and the other preparation methods were the same as in example 1.

The method of application is the same as that of RuSe prepared in examples 1 and 4₂the/Co-N-C nano composite material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the catalyst is used for preparing hydrogen under the condition that the current density is 10mA/cm²When the overpotential is 113mV。

Example 5

Compared with example 1, the difference is that RuSe is synthesized₂The annealing temperature was not changed to 300 ℃ in the/Co-N-C process.

The application method is the same as that of RuSe prepared in example 1 and example 5₂the/Co-N-C nanosheet composite material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the composite material is used for preparing hydrogen under the condition that the current density is 10mA/cm²The overpotential was 69mV.

Example 6

Compared with example 1, the difference is that RuSe is synthesized₂The annealing temperature was not changed to 500 ℃ in the/Co-N-C process.

The application method is the same as that of RuSe prepared in example 1 and example 6₂the/Co-N-C nanosheet composite material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the composite material is used for preparing hydrogen under the condition that the current density is 10mA/cm²The overpotential was 48mV.

As can be seen, the calcination temperature can affect the crystallinity of the catalyst, and the catalyst obtained at the calcination temperature of 400 ℃ has good crystallinity and catalytic activity and performance at the current density of 10mA cm^-2Under the condition of (2), the overpotential is 26mV, when the calcination temperature is only changed to 300 ℃, the crystallinity of the catalyst is not high, the formation of a heterostructure can be influenced to a certain extent, and the performance is that the current density is 10mA cm^-2The overpotential under (4) was 69mV. Only the calcination temperature is changed to 500 ℃, so that the RuSe loaded on the Co-N-C nanosheets can be obtained₂Some agglomeration of the particles occurs, which affects the catalytic activity of the catalyst. Under the calcination condition of 400 ℃, the catalyst with good crystallinity and a heterostructure can be obtained, and more active sites of Co-N-C nanosheets and RuSe2 heterostructure can be exposed, so that the catalyst has good catalytic activity.

Comparative example 1

Compared with example 1, the differences are: the preparation process is free of Fresh RuSe₂the/Co-N-C was subjected to a tube furnace calcination operation and directly tested as a working electrode.

The application method is the same as that of the embodiment1, freshRuSe prepared in comparative example 1₂the/Co-N-C nano composite material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the catalyst is used for preparing hydrogen under the condition that the current density is 10mA/cm²The overpotential was 111mV.

The invention leads the combination of RuSe2 and Co-N-C to be more compact after the calcination of the tube furnace, thereby forming RuSe₂And a Co-N-C heterostructure, thereby greatly improving the hydrogen evolution performance of the catalyst. Comparative example 1 Fresh RuSe calcination without tube furnace₂The performance of the hydrogen evolution catalyst is not greatly different from that of the Fresh Ruse2/Co-N-C, and meanwhile, if only the Fresh Ruse is used₂RuSe obtained by calcination₂The material has limited performance improvement, and only the Ruse obtained by calcining Fresh RuSe2/Co-N-C₂The great improvement of the hydrogen evolution performance of the/Co-N-C material is also shown, and the fact that the catalytic performance of the invention benefits from RuSe after calcination₂And Co-N-C.

Comparative example 2

Compared with example 1, the difference is that the Co-N-C nano-block prepared by replacing the raw material is directly used as the working electrode.

Application method As in example 1, the Co-N-C material prepared in comparative example 2 is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the Co-N-C material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the current density of 10mA/cm²The overpotential is 289mV.

Compared with example 1, the difference is that dicyandiamide is used as a nitrogen source and a carbon source, cobalt nitrate is used as a cobalt source, and the same conditions are adopted, so that a blocky cobalt-nitrogen-doped carbon structure is finally obtained, and a nanosheet structure cannot be obtained.

Comparative example 3

Compared with example 1, the difference is that RuSe is synthesized₂Co-N-C is not added in the process.

Using the same procedure as in example 1, comparative example 3 for the preparation of RuSe₂The material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the material is used for preparing hydrogen under the condition that the current density is 10mA/cm²The overpotential was 90mV.

Comparative example 4

Compared with example 1, the difference is that in the synthesis of FreshRuSe₂Co-N-C is not added in the process, and the annealing operation is not carried out in a 400 ℃ tube furnace.

The procedure used was the same as that used in example 1 and comparative example 4 to prepare FreshRuSe₂The material is used for preparing hydrogen by electrocatalytic decomposition of water in KOH electrolyte with the concentration of 1mol/L, and the cathode of the material is used for preparing hydrogen under the condition that the current density is 10mA/cm²The overpotential was 113mV.

Claims

1. RuSe₂The preparation method of the/Co-N-C nano composite material is characterized by comprising the following specific steps:

(1) Taking cobalt acetylacetonate (II) as a cobalt source, dissolving the cobalt source, urea and glucose into deionized water, and stirring to obtain a pink transparent uniform solution;

(2) Putting the solution obtained in the step (1) in a drying box, completely evaporating pink transparent uniform solution to dryness to obtain a white crystalline precursor, containing the white crystalline precursor by using a crucible, transferring the white crystalline precursor to a tubular furnace, and introducing N₂Heating to 900 deg.C as protective gas, calcining, and introducing N₂Naturally cooling to room temperature, and collecting black solids to obtain Co-N-C nanosheets;

(3) Preparation of Fresh RuSe by hydrothermal method₂Co-N-C nanocomposites: dispersing Co-N-C nanosheets in deionized water, and ultrasonically and violently stirring to obtain Se powder and RuCl₃Adding into the solution, stirring vigorously, adding hydrazine hydrate, transferring the obtained solution into a high-pressure reaction kettle serving as a reaction container, heating for reaction, naturally cooling the reaction kettle to room temperature after the reaction is finished, pouring out the liquid, centrifuging, collecting the precipitate, cleaning, and drying to obtain Fresh RuSe₂/Co-N-C；

(4) Fresh Ruse₂Thermal annealing treatment of/Co-N-C in a tube furnace to produce RuSe₂Co-N-C nanocomposites: fresh Ruse₂the/Co-N-C is loaded in a crucible and arranged in a tube furnace, and N is introduced₂As protective gas, the temperature is raised to 300 to 500 ℃ for calcination, and the calcined product is naturally cooledCooling to room temperature to obtain the final product RuSe₂/Co-N-C。

2. The Ruse according to claim 1₂The preparation method of the/Co-N-C nano composite material is characterized in that the mass ratio of cobalt acetylacetonate (II) to urea in the step (1) is 1:150 to 200.

3. The Ruse according to claim 1₂The preparation method of the/Co-N-C nano composite material is characterized in that the mass ratio of cobalt acetylacetonate (II) to glucose in the step (1) is 1:10 to 15.

4. The RuSe of claim 1₂The preparation method of the/Co-N-C nano composite material is characterized in that Se powder and RuCl are used in the step (3)₃The mass ratio of (1): 5-6, the mass ratio of the Se powder to the Co-N-C is 1.2-1.6.

5. The Ruse according to claim 1₂The preparation method of the/Co-N-C nano composite material is characterized in that the calcination time in the step (2) is 5 hours.

6. The Ruse according to claim 1₂The preparation method of the/Co-N-C nano composite material is characterized in that the temperature rise reaction condition in the step (3) is 120 ℃ and is kept for 12 hours.

7. The RuSe of claim 1₂The preparation method of the/Co-N-C nano composite material is characterized in that the calcining temperature in the step (4) is 400 ℃, and the calcining time is 2 hours.

8. RuSe prepared by the method of any one of claims 1 to 7₂Use of a/Co-N-C nanocomposite, wherein the RuSe is present₂the/Co-N-C nano composite material is used for electrocatalytic hydrogen evolution under alkaline conditions.