CN113430535A

CN113430535A - Preparation method of monatomic platinum composite electro-catalytic hydrogen evolution material

Info

Publication number: CN113430535A
Application number: CN202110795491.3A
Authority: CN
Inventors: 汪淑娟; 邹星礼; 卢明辉; 王府倩; 李想; 庞忠亚; 熊晓璐; 李光石; 鲁雄刚; 周忠福; 许茜
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2021-07-14
Filing date: 2021-07-14
Publication date: 2021-09-24
Anticipated expiration: 2041-07-14
Also published as: CN113430535B

Abstract

The invention discloses a preparation method of a monatomic platinum composite electrocatalytic hydrogen evolution material; nickel chloride, cobalt chloride and single-layer Graphene Oxide (GO) are used as raw materials; taking a eutectic solvent prepared from choline chloride/ethylene glycol as an electrolyte; adding GO into the eutectic solvent and stirring at constant temperature to form an electrolyte containing dispersed GO solid particles; a standard three-electrode system is formed by adopting a nickel sheet as a counter electrode, a carbon cloth as a working electrode and a non-mercury wire electrode as a reference electrode to carry out composite electrodeposition; then, the electrode material prepared by composite electrodeposition is put into a tubular furnace, and argon is introduced for calcination; and then, a platinum sheet is used as a counter electrode, the processed sample is used as a working electrode, a non-mercury wire electrode is used as a reference electrode, a eutectic solvent prepared from choline chloride/ethylene glycol is used as an electrolyte, a cyclic voltammetry method is selected, and different turns of the cycle are controlled to carry out loading of the monatomic platinum. The invention has excellent hydrogen evolution performance and can be applied to the field of hydrogen production by water electrolysis.

Description

Preparation method of monatomic platinum composite electro-catalytic hydrogen evolution material

Technical Field

The invention relates to the technical field of hydrogen production by water electrolysis, in particular to a preparation method of a monatomic platinum composite electro-catalytic hydrogen evolution material.

Background

With the development of society, fossil fuels are gradually used up and environmental problems force people to seek new clean energy sources. Among them, hydrogen is a promising green energy source due to its high energy density, low pollution and no greenhouse gas emission. With the popularization of electric energy, large-scale water cracking can produce high-purity hydrogen, and thus has attracted much attention, and many electrocatalysts for Hydrogen Evolution Reaction (HER) have been developed in recent years. At present, the developed hydrogen production methods mainly include hydrogen production by fossil fuels, hydrogen production by biological energy, hydrogen production by thermal decomposition of water, hydrogen production by solar water decomposition, and hydrogen production by water electrolysis. The traditional hydrogen production method is mainly used for producing hydrogen on a large scale through consumption of non-renewable energy sources. Therefore, the exploration of the high-efficiency hydrogen production technology has very important research significance for the sustainable development of the economy of China.

At present, the hydrogen production by water electrolysis has the advantages of industrial maturity, no pollution, high purity of produced hydrogen and the like, but the energy consumption of water electrolysis is still too high, so that the research and development of materials with low overpotential and high catalytic activity is the key for reducing the energy consumption. The best electrodes for electrolytic hydrogen production are mainly platinum-containing catalysts, but the low global reserves and high cost of platinum have prevented their large-scale application. In recent years, researchers have been working on increasing the efficiency of platinum utilization by reducing the amount of platinum used, wherein the reduction of platinum to cluster and monoatomic size, followed by anchoring to a carrier, is an effective method to reduce the amount of platinum and to utilize platinum atoms more efficiently, thereby maximizing the catalytic activity of various catalytic reactions. Although some progress is made in the field of single atoms at present, the harsh preparation conditions and excessive precursor of the Single Atoms (SACs) can cause platinum agglomeration and further hinder the stability of the SACs, so that the reasonable design of the single atom hydrogen evolution electrocatalyst is also very necessary.

Disclosure of Invention

In view of the above defects of the prior art, the technical problem to be solved by the present invention is to increase the specific surface area of an electrode by adding graphene oxide particles, to improve the interaction between a carrier and Pt atoms by introducing N element, and to realize the loading of Pt single atoms by a cyclic voltammetry method in a eutectic solvent.

In order to realize the aim, the invention provides a preparation method of a monatomic platinum composite electrocatalytic hydrogen evolution material, which comprises the following steps:

step one, preparation of a eutectic solvent: mixing choline chloride and ethylene glycol, and stirring at constant temperature of 40-50 ℃ until a uniform colorless transparent solution A is formed;

step two, preparing an electrolyte solution: adding metal chloride into the eutectic solvent prepared in the step one, and stirring at a constant temperature of 40 ℃ to obtain a uniform dark green transparent solution B; adding second-phase solid particles into the solution B, carrying out ultrasonic treatment for 1h, and then mixing and stirring at a constant temperature of 40-50 ℃ to finally obtain a suspended black electrolyte C;

step three, preparing an electrolytic cell: the electrolytic cell comprises an electrolytic bath and a three-electrode system, wherein the three-electrode system comprises a counter electrode, a working electrode and a reference electrode;

step four, synthesizing the Ni-Co-GO composite material: adding the electrolyte C prepared in the step two into the electrolytic cell in the step three, placing the electrolytic cell in a temperature-controlled magnetic stirring electric heating jacket, controlling the temperature to be 60-70 ℃, applying potential to a system of the electrolytic cell by using an electrochemical workstation, and carrying out composite electrodeposition;

taking the Ni-Co-GO composite material prepared by the composite electrodeposition in the step four out of the electrolytic tank, washing with deionized water, washing with absolute ethyl alcohol, and finally drying;

putting the dried sample in the step five into a porcelain boat, adding urea into the other porcelain boat which is 1cm away from the porcelain boat, putting the two porcelain boats into a tubular furnace, introducing 80-100 sccm argon into the tubular furnace, heating, keeping constant temperature for 2 hours for calcination, cleaning the calcined porcelain boat with deionized water, cleaning the calcined porcelain boat with absolute ethyl alcohol, and finally drying;

and step seven, taking the sample prepared in the step six as a working electrode, a platinum sheet electrode as a counter electrode and a non-mercury wire electrode as a reference electrode, adding the solution A into an electrolytic cell containing three electrodes, and anchoring the monatomic platinum by adopting a cyclic voltammetry method.

Further, the molar ratio of the choline chloride to the ethylene glycol in the first step is 1: 2.

Further, in the second step, the metal chlorides are 0.2M of nickel chloride hexahydrate and 0.1M of cobalt chloride hexahydrate.

Further, in the second step, the second-phase solid particles are single-layer graphene oxide, and the addition amount of the second-phase solid particles is 0.2-0.3 g.

Further, the working electrode in the third step is a carbon cloth material which is subjected to acidic activation and oil removal.

Further, in the sixth step, the temperature rise rate is 3-5 ℃/min, and the temperature rises to 300 ℃.

Further, the reference electrode in step three is a non-mercury wire electrode.

Further, in the sixth step, 0.2-0.4 g of urea is used as an N source.

Further, in the fourth step, a potential of-0.6 to-0.7V is applied to the system of the electrolytic cell, the composite electrodeposition time is controlled to be 60 to 120min, and the rotating speed is 500 to 1000 rpm.

Further, the anchoring conditions in step seven are cyclic voltammetry: the sweeping speed is 50-100 mV/s, the voltage interval is-0.6 to-1.2V, and the number of turns is 500-4000.

Compared with the prior art, the invention has the following remarkable advantages:

1. the eutectic solvent adopted by the invention has a wider electrochemical window and higher viscosity, and can better disperse the second-phase solid particles in the electrolyte and ensure the formation of a uniform composite material. In addition, the solvent is non-toxic, degradable and recyclable, and the use of the solvent for directly preparing the monatomic platinum composite electro-catalytic hydrogen evolution material by an electrochemical method is a new green, environment-friendly and controllable synthesis process;

2. the second-phase single-layer graphene is introduced, so that the active specific surface area of the electrode material can be increased, the hydrogen evolution catalytic activity of the electrode material is further improved, and in addition, due to the fact that the graphene has more defects, N atoms can be effectively embedded, and the Pt single atom fixing capacity of the whole carrier is improved;

3. according to the preparation method, after single-layer graphene particles are added, the Ni-Co-GO composite electrode material is directly prepared, and then a strong electronegative element N element is introduced to further improve the anchoring effect of the whole carrier on monatomic platinum, so that the stability of platinum in the whole system is effectively ensured;

4. the method can effectively reduce the consumption of platinum in the composite material and improve the utilization rate of the platinum, thereby effectively reducing the cost;

5. compared with other preparation methods for preparing monatomic platinum (Pt)_SA) The process of the composite electro-catalytic hydrogen evolution material is simpler, the process is greatly shortened, the process is controllable, the requirement on equipment conditions is lower, and the cost is reduced to a great extent.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a process flow diagram for preparing a monatomic platinum composite electrocatalytic hydrogen evolution material according to the present invention;

FIG. 2 is a pictorial view of an electrolyte solution used in the present invention;

FIG. 3 is a diagram of a monoatomic platinum composite electrocatalytic hydrogen evolution material prepared by the present invention;

FIG. 4 is a schematic view of an electrolytic cell apparatus for producing a composite electrocatalytic hydrogen evolution material employed in the present invention;

FIG. 5 shows Pt prepared according to example one of the present invention_SA-A micro-topography of the Ni-Co-GO-N composite material;

FIG. 6 shows Pt prepared according to example one of the present invention_SA-another micro-topography of the Ni-Co-GO-N composite;

FIG. 7 shows Pt prepared in accordance with example one of the present invention_SA-a surface-scan energy spectrum of a Ni-Co-GO-N composite;

FIG. 8 shows Pt prepared in the first embodiment of the present invention_SA-XRD spectrum of Ni-Co-GO-N composite;

FIG. 9 shows Pt prepared in accordance with example one of the present invention_SA-a spherical aberration electron microscope HAADF-STEM map of a Ni-Co-GO-N composite;

FIG. 10 shows Pt prepared according to example one of the present invention_SA-another spherical aberration electron microscope HAADF-STEM map of the Ni-Co-GO-N composite;

FIG. 11 shows Pt prepared in accordance with example one of the present invention_SA-XPS spectra of Ni-Co-GO-N composites;

FIG. 12 shows Pt prepared in example two of the present invention_SA-a micro-topography (SEM) image of a Ni-Co-GO-N composite;

FIG. 13 shows Pt prepared in example two of the present invention_SA-another micro-topography (SEM) image of the Ni-Co-GO-N composite;

FIG. 14 shows Pt prepared in example two of the present invention_SA-a surface-scan energy spectrum of a Ni-Co-GO-N composite;

FIG. 15 shows Pt prepared in example two of the present invention_SA-XRD spectrum of Ni-Co-GO-N composite;

FIG. 16 shows Pt prepared in example two of the present invention_SA-a synchrotron radiation XANES spectrum of a Ni-Co-GO-N composite;

FIG. 17 shows Pt prepared in example two of the present invention_SA-synchrotron radiation EXAFS spectrum of Ni-Co-GO-N composite;

FIG. 18 shows Pt prepared in example III of the present invention_SA-a micro-topography (SEM) image of a Ni-Co-GO-N composite;

FIG. 19 shows Pt prepared in example III of the present invention_SA-another micro-topography (SEM) image of the Ni-Co-GO-N composite;

FIG. 20 shows Pt prepared in example III of the present invention_SA-a surface-scan energy spectrum of a Ni-Co-GO-N composite;

FIG. 21 shows Pt prepared in example III of the present invention_SA-XRD spectrum of Ni-Co-GO-N composite;

FIG. 22 shows Pt prepared in example III of the present invention_SA-in-situ infrared FTIR spectrum of Ni-Co-GO-N composite.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

Example one

In the embodiment, a preparation method for preparing a monatomic platinum composite electro-catalytic hydrogen evolution material by platinum sheet electrode controlled dissolution is mainly introduced, the process flow is shown in fig. 1, and the specific operation steps are as follows:

step one, preparing a choline chloride/ethylene glycol eutectic solvent: mixing choline chloride and ethylene glycol as raw materials in a beaker according to a molar ratio of 1:2, and stirring at a constant temperature of 40 ℃ for 12 hours until a uniform colorless transparent liquid is formed, such as a solution A shown in figure 2;

step two, preparing an electrolyte solution: adding 0.2M (2.38g) of nickel chloride hexahydrate (analytically pure) and 0.1M (1.19g) of cobalt chloride hexahydrate (analytically pure) into 50mL of the eutectic solvent prepared in the first step, and stirring at a constant temperature of 40 ℃ for 2h to obtain a uniform dark green transparent liquid, such as solution B shown in FIG. 2; adding 0.3g of single-layer graphene particles (GO) into the prepared solution, carrying out ultrasonic treatment for 1 hour, and stirring at a constant temperature of 40 ℃ for 2 hours to finally obtain a suspended black liquid as an electrolyte C shown in figure 2;

step three, an electrolytic cell system: the electrolytic cell device adopted in the composite electrodeposition process is shown in fig. 4, and a 100mL polytetrafluoroethylene beaker with a sealed perforated cover is used as an electrolytic cell; the three-electrode system comprises a nickel sheet electrode (the area is 1cm multiplied by 1cm) as a counter electrode, carbon cloth (the working area is 1cm multiplied by 1cm) after acid activation and oil removal as a working electrode, and a non-mercury wire electrode (the diameter of a silver wire is 3mm) as a reference electrode; the electrolyte is the electrolyte prepared in the second step;

step four, the synthesis process of the Ni-Co-GO composite material comprises the following steps: placing the electrolytic cell system formed in the step three in a temperature-controlled magnetic stirring electric heating sleeve, controlling the temperature and keeping the temperature at 70 ℃, then applying a potential of-0.6V to the electrolytic cell system by adopting a HCP-803 type electrochemical workstation, and respectively controlling the composite electrodeposition time to be 120min and the rotating speed to be 800 rpm;

taking out the composite material prepared by the composite electrodeposition in the fourth step from an electrolytic bath, washing the composite material with deionized water for multiple times, washing the composite material with absolute ethyl alcohol for multiple times, and finally drying the composite material at low temperature to obtain carbon cloth with a black coating;

and step six, putting the dried sample in the step five into one porcelain boat, adding 0.3g of urea into the other porcelain boat which is 1cm away from the porcelain boat, putting the two porcelain boats into a tubular furnace, introducing 80sccm argon into the tubular furnace, raising the temperature to 300 ℃ at the rate of 3 ℃/min, and then keeping the constant temperature for 2 hours for calcination. Then, deionized water is used for washing the calcined product for multiple times, absolute ethyl alcohol is used for washing the calcined product for multiple times, and finally, drying is carried out;

step seven, taking the sample prepared in the step six as a working electrode, a platinum sheet electrode as a counter electrode, a non-mercury wire electrode as a reference electrode, adding 30mL of the solution A into an electrolytic cell containing three electrodes, and fixing monatomic platinum by adopting a cyclic voltammetry method, wherein the sweep rate is 100mV/s, the voltage is-0.6 to-1.2V, and the number of turns is 500;

step eight, material characterization: the composite hydrogen evolution material Pt prepared by circulating CV for 500 circles_SAPerforming surface morphology SEM characterization on the Ni-Co-GO-N, and as shown in figures 5 and 6, finding that the composite hydrogen evolution material has a uniform acanthosphere-shaped three-dimensional structure; the corresponding energy spectrum has N, Pt elements besides Ni, Co and C elements, as shown in FIG. 7. The corresponding XRD (figure 8) shows Ni and Ni₃And the N and C peaks do not have Pt peak positions, and the result shows that the N element can be successfully introduced by taking urea as a nitrogen source, and the Pt content is low, and the Pt is not aggregated into larger particles, so that the XRD cannot be detected. Fig. 9 and 10 are HAADF images of the sample taken in STEM mode, with the bright spots being Pt atoms, and it can be seen that the monoatomic Pt is more uniformly distributed on the support. FIG. 11 is an XPS test spectrum of Pt 4f for the prepared sample and 20% Pt/C, showing that the peak position of the platinum is slightly shifted in positive direction, indicating that the valence of the platinum is higher than zero. Therefore, the dissolving-depositing process of the Pt counter electrode can be realized by using the cyclic voltammetry in the eutectic solvent, and the platinum monoatomic composite electrocatalytic hydrogen evolution material can be prepared. Compared with other processes, the method has the advantages of simple preparation technology, low requirement on equipment conditions, greatly shortened process, controllable process and effectively reduced cost.

Example two

In this embodiment, a method for preparing a monatomic platinum composite electrocatalytic hydrogen evolution material by controlled dissolution of a platinum sheet electrode is mainly introduced, the process flow is shown in fig. 1, and the operation steps are substantially the same as those in the first embodiment:

step one, the same as embodiment one;

step two, preparing an electrolyte solution: adding 0.2M (2.38g) of nickel chloride hexahydrate (analytically pure) and 0.1M (1.19g) of cobalt chloride hexahydrate (analytically pure) into 50mL of the eutectic solvent prepared in the first step, and stirring at a constant temperature of 40 ℃ for 2h to obtain a uniform dark green transparent liquid, such as solution B shown in FIG. 2; adding 0.2g of single-layer graphene particles (GO) into the prepared solution, carrying out ultrasonic treatment for 1 hour, and stirring at a constant temperature of 40 ℃ for 2 hours to finally obtain a suspended black liquid as an electrolyte C shown in figure 2;

step three, the same as the first embodiment;

step four, the synthesis process of the Ni-Co-GO composite material comprises the following steps: placing the electrolytic cell system formed in the step three in a temperature-controlled magnetic stirring electric heating sleeve, controlling the temperature and keeping the temperature at 70 ℃, then applying a potential of-0.7V to the electrolytic cell system by adopting a HCP-803 type electrochemical workstation, and respectively controlling the composite electrodeposition time to be 120min and the rotating speed to be 800 rpm;

step five, the same as the first embodiment;

and step six, putting the dried sample in the step five into one porcelain boat, adding 0.4g of urea into the other porcelain boat which is 1cm away from the porcelain boat, putting the two porcelain boats into a tubular furnace, introducing 80sccm argon into the tubular furnace, raising the temperature to 300 ℃ at the rate of 3 ℃/min, and then keeping the constant temperature for 2 hours for calcination. Then, deionized water is used for washing the calcined product for multiple times, absolute ethyl alcohol is used for washing the calcined product for multiple times, and finally, drying is carried out;

step seven, taking the sample prepared in the step six as a working electrode, a platinum sheet electrode as a counter electrode, a non-mercury wire electrode as a reference electrode, adding 30mL of the solution A into an electrolytic cell containing three electrodes, and fixing monatomic platinum by adopting a cyclic voltammetry method, wherein the sweep rate is 100mV/s, the voltage is-0.6 to-1.2V, and the number of turns is 1000;

step eight, material characterization: the composite hydrogen evolution material Pt prepared by circulating CV for 1000 circles_SAPerforming surface morphology SEM characterization on the Ni-Co-GO-N, and as shown in figures 12 and 13, finding that the composite hydrogen evolution material has a uniform acanthosphere-shaped three-dimensional structure; the corresponding energy spectrum has N, Pt elements besides Ni, Co and C elements, as shown in FIG. 14. The corresponding XRD (figure 15) shows Ni and Ni₃And the N and C peaks do not have Pt peak positions, and the result shows that the N element can be successfully introduced by taking urea as a nitrogen source, and the Pt content is low, and the Pt is not aggregated into larger particles, so that the XRD cannot be detected. FIG. 16 is a graph of synchrotron radiation XAS test in which the white line intensity of the sample is between the platinum plate and platinum dioxide, illustrating the valence state of platinum in the sample between 0 and +4In between, it can be considered that its valence is Pt^δ+The EXAFS fourier transform of fig. 17 allows the coordination structure of platinum to be obtained, and the presence of the Pt-N, Pt-Ni/Co structure and the absence of the Pt-Pt structure are found by comparison to demonstrate the formation of a single atom of platinum. Therefore, the dissolving-depositing process of the Pt counter electrode can be realized by using the cyclic voltammetry in the eutectic solvent, and the platinum monoatomic composite electrocatalytic hydrogen evolution material can be prepared. Compared with other processes, the method has the advantages of simple preparation technology, low requirement on equipment conditions, greatly shortened process, controllable process and effectively reduced cost.

EXAMPLE III

step one, the same as embodiment one;

step two, preparing an electrolyte solution: adding 0.2M (2.38g) of nickel chloride hexahydrate (analytically pure) and 0.1M (1.19g) of cobalt chloride hexahydrate (analytically pure) into 50mL of the eutectic solvent prepared in the first step, and stirring at a constant temperature of 40 ℃ for 2h to obtain a uniform dark green transparent liquid, such as solution B shown in FIG. 2; adding 0.4g of single-layer graphene particles (GO) into the prepared solution, carrying out ultrasonic treatment for 1 hour, and stirring at a constant temperature of 40 ℃ for 2 hours to finally obtain a suspended black liquid as an electrolyte C shown in figure 2;

step three, the same as the first embodiment;

step four, the synthesis process of the Ni-Co-GO composite material comprises the following steps: placing the electrolytic cell system formed in the step three in a temperature-controlled magnetic stirring electric heating jacket for temperature control and keeping at 60 ℃, then applying a potential of-0.6V to the electrolytic cell system by adopting a HCP-803 type electrochemical workstation, and respectively controlling the composite electrodeposition time to be 120min and the rotating speed to be 800 rpm;

step five, the same as the first embodiment;

and step six, putting the dried sample in the step five into one porcelain boat, adding 0.2g of urea into the other porcelain boat which is 1cm away from the porcelain boat, putting the two porcelain boats into a tubular furnace, introducing 80sccm argon into the tubular furnace, raising the temperature to 300 ℃ at the rate of 3 ℃/min, and then keeping the constant temperature for 2 hours for calcination. Then, deionized water is used for washing the calcined product for multiple times, absolute ethyl alcohol is used for washing the calcined product for multiple times, and finally, drying is carried out;

step seven, taking the sample prepared in the step six as a working electrode, a platinum sheet electrode as a counter electrode, a non-mercury wire electrode as a reference electrode, adding 30mL of the solution A into an electrolytic cell containing three electrodes, and fixing monatomic platinum by adopting a cyclic voltammetry method, wherein the sweep rate is 100mV/s, the voltage is-0.6 to-1.2V, and the number of turns is 4000;

step eight, material characterization: preparing the composite hydrogen evolution material Pt by circulating CV for 4000 circles_SAPerforming surface morphology SEM characterization on the Ni-Co-GO-N, and as shown in FIGS. 18 and 19, finding that the composite hydrogen evolution material has a uniform acanthosphere-shaped three-dimensional structure; the corresponding energy spectrum has N, Pt elements besides Ni, Co and C elements, as shown in FIG. 20. The corresponding XRD (figure 21) shows Ni and Ni₃And the N and C peaks do not have Pt peak positions, and the result shows that the N element can be successfully introduced by taking urea as a nitrogen source, and the Pt content is low, and the Pt is not aggregated into larger particles, so that the XRD cannot be detected. FIG. 22 is an in-situ infrared spectrum of a sample in CO environment, wherein 2086cm is shown in the figure which is known from the comparative literature^-1No linear or bridge absorption peak was found for CO by the platinum nanoparticles, indicating the absence of a Pt-Pt structure, demonstrating the formation of a platinum monoatomic atom. Therefore, the dissolving-depositing process of the Pt counter electrode can be realized by using the cyclic voltammetry in the eutectic solvent, and the platinum monoatomic composite electrocatalytic hydrogen evolution material can be prepared. Compared with other processes, the method has the advantages of simple preparation technology, low requirement on equipment conditions, greatly shortened process, controllable process and greatly reduced cost.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A preparation method of a monatomic platinum composite electrocatalytic hydrogen evolution material is characterized by comprising the following steps:

2. The method for preparing the monatomic platinum composite electrocatalytic hydrogen evolution material of claim 1, wherein the molar ratio of the choline chloride to the ethylene glycol in the first step is 1: 2.

3. The method for preparing a monatomic platinum composite electrocatalytic hydrogen evolution material as set forth in claim 1, wherein the metal chlorides in the second step are 0.2M nickel chloride hexahydrate and 0.1M cobalt chloride hexahydrate.

4. The method for preparing the monatomic platinum composite electrocatalytic hydrogen evolution material as set forth in claim 1, wherein in the second step, the second-phase solid particles are single-layer graphene oxide, and the addition amount is 0.2-0.3 g.

5. The method for preparing the monatomic platinum composite electrocatalytic hydrogen evolution material as defined in claim 1, wherein the working electrode in the third step is a carbon cloth material which is subjected to acid activation and oil removal.

6. The preparation method of the monatomic platinum composite electrocatalytic hydrogen evolution material as set forth in claim 1, wherein in the sixth step, the temperature rise rate is 3-5 ℃/min and the temperature rises to 300 ℃.

7. The method for preparing the monatomic platinum composite electrocatalytic hydrogen evolution material of claim 1, wherein in step three the reference electrode is a non-mercury wire electrode.

8. The method for preparing the monatomic platinum composite electrocatalytic hydrogen evolution material as set forth in claim 1, wherein 0.2 to 0.4g of the urea is used as the N source in the sixth step.

9. The preparation method of the monatomic platinum composite electrocatalytic hydrogen evolution material as set forth in claim 1, wherein in the fourth step, a potential of-0.6 to-0.7V is applied to the system of the electrolytic cell, the composite electrodeposition time is controlled to be 60 to 120min, and the rotation speed is controlled to be 500 to 1000 rpm.

10. The method for preparing the monatomic platinum composite electrocatalytic hydrogen evolution material of claim 1, wherein in the seventh step, the anchoring conditions are performed by cyclic voltammetry: the sweeping speed is 50-100 mV/s, the voltage interval is-0.6 to-1.2V, and the number of turns is 500-4000.