CN111774071B

CN111774071B - Ternary metal sulfide nanosheet material, preparation method thereof and application of ternary metal sulfide nanosheet material in water electrolysis

Info

Publication number: CN111774071B
Application number: CN202010571550.4A
Authority: CN
Inventors: 吴仁兵; 费奔
Original assignee: Fudan University
Current assignee: Fudan University
Priority date: 2020-06-22
Filing date: 2020-06-22
Publication date: 2022-03-29
Anticipated expiration: 2040-06-22
Also published as: CN111774071A

Abstract

The invention relates to a ternary metal sulfide nanosheet material, and preparation and electrolytic water application thereof, wherein the preparation method of the material comprises the following steps: 1) pretreating the foam metal to obtain a matrix; 2) adding ferric chloride and sodium sulfide into water to obtain a mixed solution; 3) putting the matrix into the mixed solution, carrying out hydrothermal reaction, washing and drying to obtain a ternary metal sulfide nanosheet material; the material is used as a catalyst for water electrolysis reaction. Compared with the prior art, the ternary metal sulfide nanosheet material prepared by the method disclosed by the invention is excellent in electrocatalytic performance, simple in preparation process and low in cost, can be used for performing stable and efficient hydrogen evolution reaction, oxygen evolution reaction and total water decomposition under different current densities, and has a huge potential value in large-scale hydrogen production application.

Description

Ternary metal sulfide nanosheet material, preparation method thereof and application of ternary metal sulfide nanosheet material in water electrolysis

Technical Field

The invention belongs to the technical field of materials and energy, and relates to a universal ultrathin ternary metal sulfide nanosheet material, a preparation method thereof and an application of electrolyzed water.

Background

With the increasing consumption of fossil fuels and the increasing severity of environmental pollution, hydrogen with no carbon emissions and high energy density is considered one of the most promising energy carriers in the future. The electrochemical water decomposition is combined with intermittent solar energy and wind energy, and a sustainable and feasible method is provided for the production of the hydrogen fuel. During the electrolysis of water, two electrode half-reactions, namely the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER), mainly occur. However, due to the existence of energy barriers in the thermodynamic and kinetic processes of these two half-reactions, they require a higher overpotential to drive water splitting. Studies have shown that in order to solve the above problems, an efficient electrocatalyst may be introduced during the electrolytic water reaction to promote the exchange process of electrons and protons, thereby lowering the reaction energy barrier. Currently, noble metals and Ru/Ir-based oxides are the benchmark electrocatalysts for accelerating HER and OER, respectively. However, the natural abundance of the precious catalysts is low, the cost is high, and the scale application of the precious catalysts is greatly restricted. Therefore, it is particularly critical to develop a non-noble metal-based electrocatalyst with low cost and excellent performance to replace the noble metal-based catalyst.

In the past decades, various metal materials such as phosphide, selenide, carbide, sulfide and nitride have been widely studied due to their low cost, abundant sources, large reserves and good electrical conductivity, and are expected to be applied to the field of electrolytic water catalysts. However, most of these metal sulfides have unsatisfactory intrinsic activity, and the three-dimensional structure is embedded with more active sites and other limitations, so that the catalytic process needs to be promoted through morphology engineering and electronic structure adjustment. The former aims to create the ideal size and shape to increase the achievable surface area and expose more active sites, while the latter strategy mainly involves heterostructure building or heteroatom doping to optimize intrinsic catalytic activity. However, these methods have the disadvantages of complicated process flow, unstable process, low efficiency, etc., and are greatly limited in application.

Disclosure of Invention

The invention aims to provide a ternary metal sulfide nanosheet material, a preparation method thereof and an application of electrolyzed water, wherein the ternary metal sulfide nanosheet material has the advantages of efficient and stable process, simple process flow and capability of effectively saving energy, and can be used for catalyzing hydrogen evolution reaction, oxygen evolution reaction and total water decomposition.

The purpose of the invention can be realized by the following technical scheme:

a preparation method of a ternary metal sulfide nanosheet material comprises the following steps:

1) pretreating the foam metal to obtain a matrix;

2) adding ferric chloride and sodium sulfide into water to obtain a mixed solution;

3) and putting the matrix into the mixed solution, carrying out hydrothermal reaction, washing and drying to obtain the ternary metal sulfide nanosheet material.

Further, in step 1), the foam metal is one of nickel foam, copper foam, titanium foam, aluminum foam, cobalt foam or zinc foam.

Further, in the step 1), the pretreatment process is as follows: firstly, the foam metal is ultrasonically cleaned, and then the foam metal is dried.

Further, the ultrasonic cleaning process comprises the following steps: sequentially using acetone, ethanol and deionized water as cleaning agents, and respectively ultrasonically cleaning for 5-15 min; in the drying process, the temperature is 50-80 ℃.

Further, in the step 2), the ferric chloride is selected from a hydrate of ferric chloride, the sodium sulfide is selected from a hydrate of sodium sulfide, and the molar ratio of the ferric chloride to the sodium sulfide is 1 (1-6). Preferably, the mass ratio of the sodium sulfide to the ferric chloride is (0.2-6) mg and (0.2-2) mg.

Further, in the step 3), the temperature is 100-220 ℃ and the time is 1-48h in the hydrothermal reaction process.

Further, in the step 3), water and/or ethanol are/is adopted as a detergent in the washing process; in the drying process, the temperature is 50-80 ℃ and the time is 5-20 h.

The ternary metal sulfide nanosheet material is prepared by the method.

The application of the ternary metal sulfide nanosheet material as a catalyst is used in an electrolytic water reaction.

Further, the material is used in hydrogen evolution reaction, oxygen evolution reaction or full water decomposition of electrolyzed water.

The ternary metal sulfide nanosheet material prepared by the invention is used for catalyzing hydrogen evolution reactionThe specific steps in the process are (Fe)_0.9Ni_2.1S₂@ NF for example): prepared Fe_0.9Ni_2.1S₂The @ NF electrocatalyst was used as a working electrode, Hg/HgO was used as a reference electrode, and a carbon rod was used as a counter electrode. HER was tested for electrochemical performance in 1.0M KOH solution saturated with nitrogen, including linear sweep voltammetry and time-current density testing.

When the catalyst is used for catalyzing the oxygen evolution process, the specific steps are (Fe)_0.9Ni_2.1S₂@ NF for example): prepared Fe_0.9Ni_2.1S₂The @ NF electrocatalyst was used as a working electrode, Hg/HgO was used as a reference electrode, and a carbon rod was used as a counter electrode. The OER was tested for electrochemical performance in a 1.0M KOH solution saturated with oxygen, including linear sweep voltammetry and time-current density tests.

When the catalyst is used for catalyzing the decomposition of the total water, the specific steps are (Fe)_0.9Ni_2.1S₂@ NF for example): prepared Fe_0.9Ni_2.1S₂The @ NF electrocatalyst serves as the cathode and anode, respectively. The electrochemical performance of the full water splitting was tested in a saturated 1.0M KOH solution, including a linear sweep voltammetry test and a time-current density test.

The invention takes commercial foam nickel, foam copper, foam aluminum or foam titanium and other foam metals as a substrate, and prepares the self-supporting type electrocatalyst material of a ternary metal sulfide nanosheet array loaded on the substrate by carrying out sodium sulfide in-situ etching and iron doping induced two-dimensional reaction on the foam metals. The catalyst material is a synthesis process of directly etching on a foam metal substrate, and a unique two-dimensional support structure can be formed without consuming any energy. The ultrathin structure has larger specific surface area and faster mass transfer and electron transfer capabilities. Furthermore, the reduced active center electron cloud density can significantly reduce the adsorption free energy of the catalyst for hydrogen/oxygen intermediates. These advantages contribute to excellent electrocatalytic performance when performing hydrogen evolution reactions, oxygen evolution reactions, and total water splitting (e.g., Fe in 1.0M KOH solution_0.9Ni_2.1S₂The HER overpotential of @ NF: eta_{10mA cm-2}72mV, OER overpotential: eta_{10mA cm-2}252mV, full water decomposition potential: eta_{10mA cm-2}1.51V) and can maintain extremely high stability at various current densities (e.g., Fe in a 1.0M KOH solution_0.9Ni_2.1S₂@ NF hydrogen and oxygen evolution electrocatalyst can be at 10mA cm^-2And 100mA cm^-2Almost no decay after 24h at current density, the all-water decomposition electrocatalyst can be at 10mA cm^-2No attenuation after 100h under the current density and can maintain 10mA cm^-2Stability of current density near 100%).

The ultrathin ternary metal sulfide nanosheet electrocatalyst material prepared by the method disclosed by the invention has the advantages of excellent electrocatalytic performance, simple preparation process, wide raw material source and low cost, can be used for performing stable and efficient hydrogen evolution reaction, oxygen evolution reaction and full water decomposition under different current densities, keeps extremely low reaction energy consumption, and has huge potential value in large-scale hydrogen production application.

Compared with the prior art, the invention has the following characteristics:

1) the ternary metal sulfide nanosheet material prepared by the method has an ordered two-dimensional structure with ultrathin characteristics and higher surface area-to-volume ratio, and can ensure the full exposure and the rapid charge/electron transfer of active sites.

2) The invention develops a simple, universal and extensible method for the first time, namely, foamed metal (MF, M ═ Ni, Cu, Ti, Al and the like) is doped with Fe and then passes through Na₂And the chemical etching process induced by S is converted into an atomic thin ternary metal sulfide array in situ on MF.

3) The doping introduction of Fe not only promotes the formation of a nanosheet array with abundant active sites, but also effectively reduces the electron density of the surface active centers with the best intrinsic activity.

Drawings

FIG. 1 shows Fe prepared in example 1_0.9Ni_2.1S₂@ NF electrocatalyst (left panel) and Ni prepared without adding iron chloride₃S₂Scanning electron microscope of @ NF electrocatalyst (right drawing)Figure (SEM);

FIG. 2 shows Fe prepared in example 1_0.9Ni_2.1S₂Transmission Electron Microscopy (TEM) of @ NF electrocatalyst;

FIG. 3 is Fe prepared in example 1_0.9Ni_2.1S₂X-ray diffraction energy spectrum analysis (XRD) of @ NF electrocatalyst;

FIG. 4 is Fe prepared in example 1_0.9Ni_2.1S₂@ NF electrocatalyst, OER linear sweep voltammogram in 1.0 moles per liter of potassium hydroxide electrolyte at a sweep rate of 5 millivolts per second;

FIG. 5 shows Fe prepared in example 1_0.9Ni_2.1S₂@ NF electrocatalyst, loaded with different stable current densities, OER current density-time profile in 1.0 mol/L KOH electrolyte;

FIG. 6 is Fe prepared in example 1_0.9Ni_2.1S₂@ NF electrocatalyst, HER linear sweep voltammogram in 1.0 moles per liter of potassium hydroxide electrolyte at a scan rate of 5 millivolts per second;

FIG. 7 is Fe prepared in example 1_0.9Ni_2.1S₂@ NF electrocatalyst, loaded with different stable current densities, HER current density-time profile in 1.0 mol/L KOH electrolyte;

FIG. 8 is Fe prepared in example 1_0.9Ni_2.1S₂@ NF electrocatalyst, full water decomposition linear sweep voltammogram in 1.0 mole per liter of potassium hydroxide electrolyte at a scan rate of 5 millivolts per second;

FIG. 9 is Fe prepared in example 1_0.9Ni_2.1S₂@ NF electrocatalyst, load 10mA cm^–2The total water decomposition current density-time curve in 1.0 mol/l potassium hydroxide electrolyte;

FIG. 10 is Fe prepared in example 2_xCu_2-xS @ CF electrocatalyst (left panel) and Cu prepared without iron chloride₂Scanning Electron Micrograph (SEM) of S @ CF electrocatalyst (right panel);

FIG. 11 is Fe prepared in example 3_xTi_yScanning Electron Micrographs (SEM) of S @ TF electrocatalyst (left panel) and TiS @ TF electrocatalyst prepared without iron chloride (right panel);

FIG. 12 is Fe prepared in example 4_xAl_yScanning Electron Micrographs (SEM) of S @ AF electrocatalyst (left panel) and AlS @ AF electrocatalyst prepared without iron chloride (right panel).

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

Example 1:

ternary metal sulfide nanosheet Fe_0.9Ni_2.1S₂The preparation method of the @ NF electrocatalyst comprises the following steps of:

1) cutting blank foam nickel (1cm multiplied by 2cm) and respectively performing ultrasonic treatment for 15min by using acetone, ethanol and deionized water, removing surface pollutants, and putting the blank foam nickel into a 60 ℃ oven for 6 hours to be used as a matrix;

2) adding 0.81mg of ferric chloride and 1.2mg of sodium sulfide into 50ml of water, and fully dissolving to obtain a mixed solution;

3) transferring the mixed solution into a 100ml reaction kettle;

4) putting the cleaned foam nickel into the mixed solution, and setting the hydrothermal temperature at 150 ℃ and the hydrothermal time for 6 hours to obtain the ternary metal sulfide nanosheet electrocatalyst;

5) the obtained electrocatalyst is washed with water and ethanol for three times respectively and then is dried in a 65 ℃ oven for 12 hours.

Fe to be prepared_0.9Ni_2.1S₂The @ NF electrocatalyst is used for catalyzing the hydrogen evolution reaction process and comprises the following specific steps: mixing Fe_0.9Ni_2.1S₂The @ NF electrocatalyst was used as a working electrode, Hg/HgO was used as a reference electrode, and a carbon rod was used as a counter electrode. Testing of HER electrochemical performance in nitrogen saturated 1.0M KOH solution, including linear sweep voltammetry testAnd time-current density testing.

When the catalyst is used for the catalytic oxygen evolution process, the method comprises the following specific steps: mixing Fe_0.9Ni_2.1S₂The @ NF electrocatalyst was used as a working electrode, Hg/HgO was used as a reference electrode, and a carbon rod was used as a counter electrode. The OER was tested for electrochemical performance in a 1.0M KOH solution saturated with oxygen, including linear sweep voltammetry and time-current density tests.

When the catalyst is used for catalyzing the decomposition of total water, the specific steps are as follows: mixing Fe_0.9Ni_2.1S₂The @ NF electrocatalyst serves as the cathode and anode, respectively. The electrochemical performance of the full water splitting was tested in a saturated 1.0M KOH solution, including a linear sweep voltammetry test and a time-current density test.

FIG. 1 is Fe prepared_0.9Ni_2.1S₂@ NF electrocatalyst and Ni prepared without adding iron chloride₃S₂Scanning Electron Microscopy (SEM) for the @ NF electrocatalyst, as can be seen in FIG. 1, Fe_0.9Ni_2.1S₂The @ NF electrocatalyst has a two-dimensional nano sheet structure, and the two-dimensional nano sheets have the characteristics of large specific surface area, ultrathin property and complete sheet shape. Ni can be effectively regulated and controlled by changing Fe doping amount₃S₂Growing in two dimensions and growing into two-dimensional nanoplatelets having a suitable size, atomic layer thickness. It is due to this structure that Fe_0.9Ni_2.1S₂@ NF not only having Ni₃S₂Metal sulfide has the advantage of good conductivity, and effectively converts Ni into Ni₃S₂The metal sulfide is converted into a two-dimensional structure from a three-dimensional structure, more active sites are exposed and fully combined with a catalytic substrate, and the electrocatalytic activity is greatly improved.

FIG. 2 shows Fe prepared_0.9Ni_2.1S₂Transmission Electron Microscopy (TEM) of the @ NF electrocatalyst, Fe can be seen in FIG. 2_0.9Ni_2.1S₂@ NF exhibited a translucent character, indicating that it is an ultra-thin nanosheet, only atomic layer thick. The TEM result is more consistent with the SEM, and proves that Fe is doped to effectively regulate and control Ni₃S₂Two-dimensional growth of Fe_0.9Ni_2.1S₂The structure of @ NF is ultrathin, and more active sites are exposed, so that the catalytic performance of the electrocatalyst is promoted.

FIG. 3 is Fe prepared_0.9Ni_2.1S₂X-ray diffraction Spectroscopy (XRD) of @ NF electrocatalyst, as seen from FIG. 3, the diffraction peak of nickel foam, Fe, was removed_0.9Ni_2.1S₂@ NF exhibited four main peaks near 21.8 °, 31.1 °, 50.1 ° and 55.2 °, which should correspond to Ni₃S₂The (101), (110), (113) and (122) planes of (1). Pure Ni₃S₂Maximum diffraction Peak at 31.1 ℃ with Fe_0.9Ni_2.1S₂The @ NF comparison shows obvious positive migration, and proves that Fe is successfully doped into Ni₃S₂In (1).

FIG. 4 shows Fe prepared_0.9Ni_2.1S₂@ NF electrocatalyst, OER Linear sweep voltammogram in 1.0 mol/L KOH electrolyte at a sweep rate of 5 millivolts per second, as can be seen in FIG. 4, Fe_0.9Ni_2.1S₂@ NF also has very excellent OER performance at 100mA cm^-2The OER overpotential is only 252mV at the current density of (1).

FIG. 5 shows Fe prepared_0.9Ni_2.1S₂@ NF electrocatalyst, load 10mA cm^-2And 100mA cm^-2Stable current density, OER current density vs. time plot in 1.0 mol/L KOH electrolyte, as can be seen in FIG. 5, Fe_0.9Ni_2.1S₂@ NF has very stable electrocatalytic cycle performance. There was no decay after 24 hours cycling, and stable and efficient OER applications could be achieved.

FIG. 6 is Fe prepared_0.9Ni_2.1S₂@ NF electrocatalyst, HER Linear sweep voltammogram at a sweep rate of 5 millivolts per second in 1.0 moles per liter of KOH electrolyte, as can be seen in FIG. 6, Fe_0.9Ni_2.1S₂@ NF also has very excellent HER performance at 10mA cm^-2HER overpotential was only 72mV at current density of (a).

FIG. 7 shows Fe prepared_0.9Ni_2.1S₂@ NF electrocatalyst, load 10mA cm^-2And 100mA cm^-2Stable current density, HER Current Density vs. time plot in 1.0 mol/L KOH electrolyte, as can be seen in FIG. 7, Fe_0.9Ni_2.1S₂@ NF has very stable HER properties. There was no decay after 24 hours cycling, and stable and efficient HER application could be achieved.

FIG. 8 shows Fe prepared_0.9Ni_2.1S₂@ NF electrocatalyst, full water decomposition Linear sweep voltammogram in 1.0 mol/L KOH electrolyte at a scan rate of 5 millivolts per second, as can be seen in FIG. 8 due to Fe_0.9Ni_2.1S₂@ NF has better HER and OER performances at the same time, and the full water decomposition of the @ NF also has better performance. At 10mA cm^-2The total water decomposition voltage only needs 1.51V under the current density of (2), which is also quite consistent with the experimental conclusion.

FIG. 9 is Fe prepared_0.9Ni_2.1S₂@ NF electrocatalyst, load 10mA cm^-2Stable current density, full water decomposition current density-time plot in 1.0 mol/L KOH electrolyte, as can be seen in FIG. 9, Fe_0.9Ni_2.1S₂@ NF has very stable electrocatalytic cycle performance. There was also only a slight decay after 100 hours of cycling, enabling stable and efficient full water decomposition applications.

Example 2:

in this example, the nickel foam was changed to copper foam, and the remainder of the example 1 was conducted to obtain Fe_xCu_2-xS @ CF electrocatalyst.

FIG. 10 is Fe_xCu_2-xS @ CF electrocatalyst and Cu prepared without adding ferric chloride₂SEM image of S @ CF electrocatalyst, which can be seen at Na₂Particles can be formed in the etching process of S, and if Fe doping is introduced in the etching process, Cu can be effectively regulated and controlled₂S forms a hexagonal sheet shape.

Example 3:

in the embodiment, the nickel foam is changed into the titanium foam,fe was obtained in the same manner as in example 1_xTi_yS @ TF electrocatalyst.

FIG. 11 is Fe_xTi_ySEM images of the S @ TF electrocatalyst and the TiS @ TF electrocatalyst prepared without adding ferric chloride show that amorphous TiS is changed into a nanosheet structure from a three-dimensional network structure after Fe doping.

Example 4:

in this example, Fe was prepared in the same manner as in example 1 except that foamed nickel was changed to foamed aluminum_xAl_yS @ AF electrocatalyst.

FIG. 12 is Fe_xAl_ySEM images of the S @ AF electrocatalyst and the AlS @ AF electrocatalyst prepared without adding ferric chloride can also see that amorphous AlS is changed into a two-dimensional nanosheet array from a granular state.

One-step Na by using different foamed metal substrates₂S etching and Fe element introduction can effectively convert the conductive metal sulfide into ternary metal sulfide nanosheets. The method is a universal method, can be suitable for different metal substrates, and further effectively develops a novel electrocatalyst. Wherein, Fe_0.9Ni_2.1S₂The @ NF two-dimensional nanosheet has the optimal size, thickness and distribution density, so that the @ NF two-dimensional nanosheet has the advantages of being high in specific surface area, more in active sites and lower in electron cloud density, and can bring better catalytic activity.

Example 5:

ternary metal sulfide nanosheet (Fe)_0.3Ni_2.7S₂@ NF) comprising the steps of:

2) adding 0.27mg of ferric chloride and 1.2mg of sodium sulfide into 50ml of water, and fully dissolving to obtain a mixed solution;

3) transferring the mixed solution into a 100ml reaction kettle;

4) putting the cleaned foam nickel into the mixed solution, and setting the hydrothermal temperature at 180 ℃ and the hydrothermal time for 12 hours to obtain ternary metal sulfide nanosheets;

5) and washing the obtained ternary metal sulfide nanosheet with water and ethanol for three times respectively, and then drying the nanosheet in an oven at 65 ℃ for 24 hours.

Example 6:

ternary metal sulfide nanosheet (Fe)_0.6Ni_2.4S₂@ NF) comprising the steps of:

2) adding 0.54mg of ferric chloride and 1.2mg of sodium sulfide into 50ml of water, and fully dissolving to obtain a mixed solution;

3) transferring the mixed solution into a 100ml reaction kettle;

4) putting the cleaned foam nickel into the mixed solution, and setting the hydrothermal temperature at 220 ℃ and the hydrothermal time for 24 hours to obtain ternary metal sulfide nanosheets;

5) and washing the obtained ternary metal sulfide nanosheet with water and ethanol for three times respectively, and then drying the nanosheet in an oven at 65 ℃ for 6 hours.

Example 7:

ternary metal sulfide nanosheet (Fe)_1.2Ni_1.8S₂@ NF) comprising the steps of:

2) adding 1.05mg of ferric chloride and 1.2mg of sodium sulfide into 50ml of water, and fully dissolving to obtain a mixed solution;

3) transferring the mixed solution into a 100ml reaction kettle;

4) putting the cleaned foam nickel into the mixed solution, and setting the hydrothermal temperature at 100 ℃ and the hydrothermal time for 2 hours to obtain ternary metal sulfide nanosheets;

5) and washing the obtained ternary metal sulfide nanosheet with water and ethanol for three times respectively, and then drying the nanosheet in an oven at 65 ℃ for 2 hours.

Example 8:

ternary metal sulfide nanosheet (Fe)_xCo_yS @ CF), comprising the steps of:

1) cutting blank foam cobalt (1cm multiplied by 2cm) and respectively performing ultrasonic treatment for 15min by using acetone, ethanol and deionized water, removing surface pollutants, and putting the blank foam cobalt into a 70 ℃ oven for 12 hours to be used as a matrix;

3) transferring the mixed solution into a 100ml reaction kettle;

4) putting the cleaned foam cobalt into the mixed solution, and setting the hydrothermal temperature at 160 ℃ and the hydrothermal time for 2 hours to obtain ternary metal sulfide nanosheets;

5) and washing the obtained ternary metal sulfide nanosheet with water and ethanol for three times respectively, and then drying the nanosheet in an oven at 65 ℃ for 12 hours.

Example 9:

ternary metal sulfide nanosheet (Fe)_xZn_yS @ ZF), comprising the steps of:

1) cutting blank foam zinc (1cm multiplied by 2cm) and respectively performing ultrasonic treatment for 15min by using acetone, ethanol and deionized water, removing surface pollutants, and putting the blank foam zinc into an oven at 80 ℃ for 12 hours to be used as a matrix;

3) transferring the mixed solution into a 100ml reaction kettle;

4) putting the cleaned foam zinc into the mixed solution, and setting the hydrothermal temperature at 200 ℃ and the hydrothermal time for 6 hours to obtain ternary metal sulfide nanosheets;

5) and (3) washing the obtained ternary sulfide with water and ethanol for three times respectively, and then putting the washed ternary sulfide into a 65 ℃ oven for drying for 12 hours.

Various parameters of the preparation process of the ternary metal sulfide nanosheet material in the above embodiments can be selected according to actual conditions and actual requirements, for example:

in the step 1), the pretreatment process comprises the following steps: firstly, the foam metal is ultrasonically cleaned, and then the foam metal is dried. Wherein, the ultrasonic cleaning process is as follows: sequentially cleaning with acetone, ethanol, and deionized water as cleaning agent by ultrasonic cleaning for 5-15min (such as 7min, 10min, and 13 min); the temperature is 50-80 deg.C (such as 55 deg.C, 65 deg.C, 75 deg.C) during the drying process.

In the step 2), the molar ratio of the ferric chloride to the sodium sulfide is 1 (1-6) (for example, 1:2, 1:4, 1: 5).

In the step 3), the temperature is 100-220 ℃ (for example, 130 ℃, 180 ℃, 200 ℃) in the hydrothermal reaction process, and the time is 1-48h (for example, 5h, 24h, 36 h). In the washing process, water and/or ethanol are/is used as a detergent; the drying process is carried out at 50-80 deg.C (such as 60 deg.C, 70 deg.C, 78 deg.C) for 5-20h (such as 10h, 15h, 18 h).

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. A preparation method of a ternary metal sulfide nanosheet material is characterized by comprising the following steps:

1) pretreating the foam metal to obtain a matrix;

3) putting the matrix into the mixed solution, carrying out hydrothermal reaction to carry out sodium sulfide in-situ etching and iron doping induction bidimensional reaction on the matrix, and then washing and drying to obtain the ternary metal sulfide nanosheet material;

in the step 1), the pretreatment process comprises the following steps: firstly, ultrasonically cleaning foam metal, and then drying; the ultrasonic cleaning process comprises the following steps: sequentially using acetone, ethanol and deionized water as cleaning agents, and respectively ultrasonically cleaning for 5-15 min; in the drying process, the temperature is 50-80 ℃;

in the step 2), the molar ratio of the ferric chloride to the sodium sulfide is 1 (1-6);

in the step 3), the temperature is 100-220 ℃ and the time is 1-48h in the hydrothermal reaction process.

2. The method for preparing a ternary metal sulfide nanosheet material as recited in claim 1, wherein in step 1), the metal foam is one of nickel foam, copper foam, titanium foam, aluminum foam, cobalt foam, or zinc foam.

3. The method for preparing the ternary metal sulfide nanosheet material as recited in claim 1, wherein in the step 3), water and/or ethanol is/are used as a detergent in the washing process; in the drying process, the temperature is 50-80 ℃ and the time is 5-20 h.

4. A ternary metal sulphide nanosheet material, wherein the material is prepared by the method of any one of claims 1 to 3.

5. Use of the ternary metal sulfide nanosheet material of claim 4 as a catalyst for use in an electrolytic water reaction.

6. The use of a ternary metal sulfide nanosheet material as recited in claim 5, wherein the material is used in a hydrogen evolution reaction, an oxygen evolution reaction or a total water splitting of electrolyzed water.