CN116334681A - NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Preparation method and application of composite nano-sheet electrode material - Google Patents

NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Preparation method and application of composite nano-sheet electrode material Download PDF

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CN116334681A
CN116334681A CN202211664628.2A CN202211664628A CN116334681A CN 116334681 A CN116334681 A CN 116334681A CN 202211664628 A CN202211664628 A CN 202211664628A CN 116334681 A CN116334681 A CN 116334681A
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hydrotalcite
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陈龙
彭尚龙
王利平
刘彦鹏
马飞
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Lanzhou University
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    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
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    • C25B1/04—Hydrogen or oxygen by electrolysis of water
    • B—PERFORMING OPERATIONS; TRANSPORTING
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    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
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    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
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    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
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    • C01P2002/20—Two-dimensional structures
    • C01P2002/22—Two-dimensional structures layered hydroxide-type, e.g. of the hydrotalcite-type
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    • C01P2004/03—Particle morphology depicted by an image obtained by SEM
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Abstract

The invention provides a NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 The method prepares solution of cobalt nitrate hexahydrate, nickel nitrate hexahydrate, ammonium fluoride and urea, directly grows nickel cobalt hydrotalcite on foam nickel by a hydrothermal method, finally uses sodium sulfide nonahydrate solution as a sulfur source, and carries out partial vulcanization on the nickel cobalt hydrotalcite by a hydrothermal method again to obtain NiCo hydrotalcite/Ni-like compound 3 S 2 /Co 9 S 8 And (3) compounding the nano-sheet electrode material, and directly applying the obtained electrode material to alkaline electrolyzed water and electrolyzed seawater to prepare hydrogen and oxygen. The composite nano-sheet electrode material obtained by the method has rich structural defects, so that more high catalytic active sites exist, the production efficiency of hydrogen and oxygen is promoted, the conductivity of the material is increased due to the synergistic effect between the composite materials and the structural characteristics of the composite, the electron transmission rate is improved, and meanwhile, the synthesized material has the advantages of low cost, good stability, simple preparation method and the like. Solves the problems of high price, low catalytic activity, poor conductivity and the like of the water electrolysis catalyst material.

Description

NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Preparation method and application of composite nano-sheet electrode material
Technical Field
The invention relates to the technical field of nano material electrocatalysis, in particular to a NiCo hydrotalcite-like compound/Ni for electrolysis of water 3 S 2 /Co 9 S 8 The preparation method and the application of the composite nano-sheet electrode material have the advantages of excellent electrocatalytic activity, high conductivity, excellent stability and the like.
Background
Social progress drives economic development, which drives energy consumption, which causes serious ecological problems, and scientific researchers put more and more effort on efficient and clean energy development. The hydrogen and oxygen are one of the important points of research, and the hydrogen energy is a green renewable clean energy source and is hopeful to become a new energy carrier for replacing fossil fuel. But Pt and RuO as the most efficient catalysts in hydrogen and oxygen production 2 /IrO 2 The content in the earth is small, and the content is severely limited in practical application. In addition, the water resource commonly used for electrolyzing water is pure water, so that the large-scale production and utilization can be limited to a certain extent, and the seawater which is the water resource with the largest earth reserve can become the mainstream electrolysis resource, so that on one hand, the seawater can be desalted, and on the other hand, the abundant hydrogen resource can be obtained. Based on the above problems, development of a low-cost and high-efficiency electrolytic water catalyst has been a main object of study.
The layered double hydroxide-based catalyst has the advantages of high catalytic activity, low cost, large reserve and the like as a two-dimensional layered material, and gradually becomes a catalyst with very promising development in the field of water electrolysis. However, hydrotalcite has the disadvantages of poor conductivity, less exposed active sites and the like when used as an electrolyzed water catalyst. In addition, the transition metal sulfide has good conductivity. However, transition metal sulfides tend to oxidize easily, and therefore have poor stability at oxidation potential. Combining stable transition metal hydroxides or oxides with transition metal sulfides, building hybrid nanostructures is considered a promising strategy to accelerate the electrolyzed water reaction kinetics and improve stability.
In addition, the synergistic effect of different metal sulfides and hydrotalcite-like compounds can generate structural defects, activate inert active sites and further improve electrochemical catalytic activity. In addition, in order to solve the problems of agglomeration of the catalyst and poor conductivity, a three-dimensional (3D) hetero-nanostructure can be effectively prepared on a conductive substrate. In particular, the nano-structure catalyst directly grown on the conductive substrate can keep the mechanical stability of the catalyst and can also improve the electron transfer rate, so that the electrocatalyst with better electrocatalytic activity is obtained.
Therefore, we designed a mixed phase nano-sheet array as alkaline electrolyzed water and electrolyzed seawater catalyst, and uses simple microwave hydrothermal reaction to partially vulcanize NiCo nano-sheets to synthesize NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 A composite material. The design concept is based on the fact that hydrotalcite-like compounds and other active materials are hybridized to form composite materials, and the synergistic effect among the composite materials and the structural characteristics of the composite reduce the electron transmission resistance; sulfide has better conductivity and is generally regarded as a high-activity OER electrocatalyst, but sulfide has poorer stability, hydrotalcite-like materials have better stability but conductivity phase difference, and the advantages of NiCo hydrotalcite-like compounds and sulfide combined with the NiCo hydrotalcite-like compounds are overcome; in addition, the crystal phase structure of the NiCo hydrotalcite-like compound can be damaged in the vulcanization process to form amorphous defects, more oxygen vacancy defects exist in the amorphous defects, and active sites in unsaturated atoms are considered to have better electrocatalytic activity.
Disclosure of Invention
The invention aims to provide a NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 The method prepares solution of cobalt nitrate hexahydrate, nickel nitrate hexahydrate, ammonium fluoride and urea, directly grows nickel cobalt hydrotalcite on foam nickel by a hydrothermal method, finally uses sodium sulfide nonahydrate solution as a sulfur source, and carries out partial vulcanization on the nickel cobalt hydrotalcite by a hydrothermal method again to obtain NiCo hydrotalcite/Ni-like compound 3 S 2 /Co 9 S 8 And (3) compounding the nano-sheet electrode material, and directly applying the obtained electrode material to electrolyzed water to prepare hydrogen and oxygen. The composite nano-sheet electrode material obtained by the method has the advantages of excellent electrocatalytic activity, high conductivity, excellent stability and the like. Solves the problems of high price, low catalytic activity, poor conductivity and the like of the water electrolysis catalyst material.
The invention relates to a NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 The preparation method of the composite nano-sheet electrode material comprises the following steps:
preparing nickel cobalt hydrotalcite by a hydrothermal method:
a. dissolving nickel nitrate hexahydrate, cobalt nitrate hexahydrate, ammonium fluoride and urea in deionized water according to a molar ratio of 0.5-4:1:3.6:9, and stirring for 1-2 hours by a magnetic stirrer under the condition of room temperature to form a transparent pink solution;
b. transferring the transparent pink solution obtained in the step a into a high-pressure reaction kettle lining, simultaneously vertically hanging foam nickel into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into a baking oven, setting the hydrothermal temperature to be 100-200 ℃ and the reaction time to be 4-12h;
c. after the hydrothermal reaction is finished, cooling the reaction kettle to room temperature, taking out a product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, and placing the product in a vacuum oven for drying at the temperature of 40-60 ℃ for 2-6 hours to obtain nano flaky nickel-cobalt hydrotalcite;
preparation of NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Composite nanoRice slices:
d. dissolving sodium sulfide nonahydrate into deionized water to prepare a sodium sulfide nonahydrate aqueous solution with the concentration of 0.5mmol/L-118mmol/L, and stirring the aqueous solution for 1-2h by a magnetic stirrer at room temperature to form a transparent solution;
e. transferring the transparent solution of sodium sulfide nonahydrate prepared in the step d into a high-pressure reaction kettle lining, simultaneously vertically hanging the nano flaky nickel-cobalt hydrotalcite obtained in the step c into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into microwave hydrothermal equipment, setting the microwave hydrothermal power to be 600-800W, and setting the temperature to be 100-160 ℃ and the reaction time to be 3-10h;
f. after the hydrothermal end, cooling the reaction kettle to room temperature, taking out the product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, placing the product in a vacuum oven for drying at 40-60 ℃ for 2-6h to obtain NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Composite nano-sheet electrode material.
The loading capacity of the prepared composite nano sheet electrode material on the foam nickel is 6-20mg, and Ni 3 S 2 /Co 9 S 8 The composite nano-sheet vertically grows on the NiCo hydrotalcite-like nano-sheet, the thickness of the formed nano-sheet is 0.05-0.15um, and the edge length is 0.1-0.9um.
NiCo hydrotalcite-like compound/Ni obtained by the method 3 S 2 /Co 9 S 8 The application of the composite nano-sheet electrode material in preparing hydrogen and oxygen in the electrolyzed water by alkaline electrolyzed water and electrolyzed seawater.
Alkaline electrocatalytic properties: at 10mA cm -2 At current density, hydrogen evolution reaction overpotential is 110-180mV, at 100mA cm -2 When the current density is reached, the overpotential of the oxygen evolution reaction is 233-330mV, and the full water decomposition reaction only needs 1.4-1.7V to reach 10mA/cm 2 Current density; for real seawater conditions, the full water decomposition reaction requires about 1.86-2.1V voltage to reach 10mA/cm 2 Current density.
Drawings
FIG. 1 shows NiCo hydrotalcite-like compound/Ni prepared in example 2 of the present invention 3 S 2 /Co 9 S 8 Scanning Electron Microscope (SEM);
FIG. 2 is a NiCo hydrotalcite-like compound/Ni prepared in example 2 of the present invention 3 S 2 /Co 9 S 8 Is characterized by X-ray diffraction;
FIG. 3 is a Ni film produced in example 3 of the present invention 3 S 2 /Co 9 S 8 Is characterized by X-ray diffraction;
FIG. 4 is an OER linear sweep voltammogram of S-NiCo hydrotalcite prepared in example 1 of the present invention;
FIG. 5 shows NiCo hydrotalcite-like compound/Ni prepared in example 2 of the present invention 3 S 2 /Co 9 S 8 Is a HER linear sweep voltammogram of (c);
FIG. 6 is a drawing of Ni prepared in example 3 of the present invention 3 S 2 /Co 9 S 8 OER linear sweep voltammogram of (c);
FIG. 7 shows NiCo hydrotalcite-like compound/Ni prepared in example 2 of the present invention 3 S 2 /Co 9 S 8 Is used for fully resolving the linear sweep voltammogram;
FIG. 8 shows NiCo hydrotalcite-like compound/Ni prepared in example 2 of the present invention 3 S 2 /Co 9 S 8 The full water splitting faraday efficiency plot of (c).
Detailed Description
The present invention and its effective technical effects are described in further detail below with reference to examples and drawings, but the embodiments of the invention are not limited thereto, and modifications and equivalents of the technical solutions of the present invention should be included in the protection scope of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Example 1
Preparing nickel cobalt hydrotalcite by a hydrothermal method:
a. dissolving nickel nitrate hexahydrate, cobalt nitrate hexahydrate, ammonium fluoride and urea in deionized water according to a molar ratio of 2:1:3.6:9, and stirring for 1h by using a magnetic stirrer at room temperature to form a transparent pink solution;
b. transferring the transparent pink solution obtained in the step a into a high-pressure reaction kettle lining, simultaneously vertically hanging foam nickel into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into a baking oven, setting the hydrothermal temperature to be 100 ℃ and the reaction time to be 4 hours
c. After the hydrothermal reaction is finished, cooling the reaction kettle to room temperature, taking out the product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, and placing the product in a drying oven for drying at the temperature of 60 ℃ for 6 hours to obtain nano flaky nickel-cobalt hydrotalcite;
preparing S-NiCo hydrotalcite-like compound composite nano-sheets:
d. dissolving sodium sulfide nonahydrate in deionized water to prepare an aqueous solution with the concentration of 0.5mmol/L, and stirring the aqueous solution for 1h by a magnetic stirrer at room temperature to form a transparent solution;
e. transferring the transparent solution of sodium sulfide nonahydrate prepared in the step d into a high-pressure reaction kettle lining, simultaneously vertically hanging the nano flaky nickel-cobalt hydrotalcite obtained in the step c into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into a baking oven, setting the hydrothermal temperature to be 100 ℃, and setting the reaction time to be 12 hours;
f. after the hydrothermal reaction is finished, cooling the reaction kettle to room temperature, taking out the product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, and placing the product in an oven for drying at the temperature of 60 ℃ for 6 hours to obtain the S-NiCo hydrotalcite-like nano-sheet electrode material;
the loading capacity of the prepared composite nano-sheet electrode material on the foam nickel is 6mg, the thickness of the formed composite nano-sheet is 0.05um, and the edge length is 0.1um;
alkaline electrocatalytic properties: at 10mA cm -2 At current density, the overpotential of hydrogen evolution reaction is 110mV, at 100mA cm -2 When the current density is reached, the overpotential of the oxygen evolution reaction is 233mV, and the full water decomposition reaction can reach 10mA/cm only by about 1.4V 2 Current density. For real seawater conditions, the full water-splitting reaction needs about 1.86V voltage to reach 10mA/cm 2 Current density;
the S-NiCo hydrotalcite-like nano electrode material obtained in example 1 is used for preparing hydrogen (H) by electrolyzing water 2 ) And oxygen (O) 2 )：
The electrocatalytic equipment adopts a three-electrode system, and consists of an electrochemical workstation, an electrolytic tank, a working electrode (S-NiCo hydrotalcite), a counter electrode graphite rod and a reference electrode silver/silver chloride;
the electrocatalytic method adopts a linear sweep voltammetry method, and related detection parameters are as follows: the standing time is set to 5s, and the scanning speed is 50mV s -1 Scanning range is 1.0-2.0V;
the electrolyte is KOH salt solution with the concentration of 1mol L -1 ；
The electrolyte in the electrolytic cell needs to be introduced with pure O 2 To make it reach saturation state, let in O 2 The time of (2) was 30min.
Example 2
Preparing nickel cobalt hydrotalcite by a hydrothermal method:
a. dissolving nickel nitrate hexahydrate, cobalt nitrate hexahydrate, ammonium fluoride and urea in deionized water according to a molar ratio of 2:1:3.6:9, and stirring for 1h by using a magnetic stirrer at room temperature to form a transparent pink solution;
b. transferring the transparent pink solution obtained in the step a into a high-pressure reaction kettle lining, simultaneously vertically hanging foam nickel into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into a baking oven, setting the hydrothermal temperature to be 200 ℃, and reacting for 12 hours;
c. after the hydrothermal reaction is finished, cooling the reaction kettle to room temperature, taking out the product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, and placing the product in a drying oven for drying at the temperature of 60 ℃ for 6 hours to obtain nano flaky nickel-cobalt hydrotalcite;
preparation of NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Composite nanoplatelet material:
d. dissolving sodium sulfide nonahydrate into deionized water to prepare an aqueous solution with the concentration of 50mmol/L, and stirring for 1h by using a magnetic stirrer at room temperature to form a transparent solution;
e. transferring the transparent solution of sodium sulfide nonahydrate prepared in the step d into a high-pressure reaction kettle lining, simultaneously vertically hanging the nano flaky nickel-cobalt hydrotalcite obtained in the step c into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into a baking oven, setting the hydrothermal temperature to be 150 ℃ and the reaction time to be 8 hours;
f. after the hydrothermal end, cooling the reaction kettle to room temperature, taking out the product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, placing the product in an oven for drying, wherein the temperature of the oven is 60 ℃ and the time is 6 hours to obtain NiCo hydrotalcite/Ni 3 S 2 /Co 9 S 8 Composite nanosheet material;
the loading capacity of the prepared composite nano sheet electrode material on the foam nickel is 12mg, and Ni 3 S 2 /Co 9 S 8 The composite material nano-sheet vertically grows on the NiCo hydrotalcite-like nano-sheet, the thickness of the formed nano-sheet is 0.1um, and the edge length is 0.5um;
alkaline electrocatalytic properties: at 10mA cm -2 At current density, the overpotential of hydrogen evolution reaction is 130mV, at 100mA cm -2 When the current density is reached, the overpotential of the oxygen evolution reaction is 255mV, and the full water decomposition reaction can reach 10mA/cm only by about 1.6V 2 The current density, for the real sea water condition, the full water-dissolving reaction needs about 1.9V voltage to reach 10mA/cm 2 Current density;
the composite nanomaterial obtained in example 2 was used to electrolyze water to produce hydrogen (H 2 ) And oxygen (O) 2 )：
The electrocatalytic equipment adopts a three-electrode system, and comprises an electrochemical workstation, an electrolytic tank and a working electrode (NiCo hydrotalcite-like compound/Ni) 3 S 2 /Co 9 S 8 ) The counter electrode graphite rod and the reference electrode silver/silver chloride;
the electrocatalytic method adopts a linear sweep voltammetry method, and related detection parameters are as follows: the standing time is set to 5s, and the scanning speed is 50mV s -1 Scanning range is 1.0-2.0V;
the electrolyte is KOH salt solution with the concentration of 1mol L -1 ；
The electrolyte in the electrolytic cell is required to be introduced with pure N 2 To make it reach saturation state, let in N 2 The time of (2) was 30min.
Example 3
Preparing nickel cobalt hydrotalcite by a hydrothermal method:
a. dissolving nickel nitrate hexahydrate, cobalt nitrate hexahydrate, ammonium fluoride and urea in deionized water according to a molar ratio of 2:1:3.6:9, and stirring for 1h by using a magnetic stirrer at room temperature to form a transparent pink solution;
b. transferring the transparent pink solution obtained in the step a into a high-pressure reaction kettle lining, simultaneously vertically hanging foam nickel into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into a baking oven, setting the hydrothermal temperature to be 150 ℃ and reacting for 8 hours;
c. after the hydrothermal reaction is finished, cooling the reaction kettle to room temperature, taking out the product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, and placing the product in a drying oven for drying at the temperature of 60 ℃ for 6 hours to obtain nano flaky nickel-cobalt hydrotalcite;
preparation of NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Composite nanoplatelet material:
d. dissolving sodium sulfide nonahydrate into deionized water to prepare an aqueous solution with the concentration of 118mmol/L, and stirring the aqueous solution for 2 hours by a magnetic stirrer at room temperature to form a transparent solution;
e. transferring the transparent solution of sodium sulfide nonahydrate prepared in the step d into a high-pressure reaction kettle lining, simultaneously vertically hanging the nano flaky nickel-cobalt hydrotalcite obtained in the step c into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into a baking oven, setting the hydrothermal temperature to be 200 ℃, and setting the reaction time to be 4 hours;
f. after the hydrothermal reaction is finished, cooling the reaction kettle to room temperature, taking out the product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, placing the product in an oven for drying, wherein the temperature of the oven is 60 ℃ and the time is 6 hours to obtain Ni 3 S 2 /Co 9 S 8 Composite nanosheet material;
the loading capacity of the prepared composite nano-sheet electrode material on the foam nickel is 20mg, the thickness of the formed nano-sheet is 0.15um, and the edge length is 0.9um;
alkaline electrocatalytic properties: at 10mA cm -2 At current densityThe overpotential of the hydrogen evolution reaction is 180mV, and the overpotential is 100mA cm -2 When the current density is reached, the overpotential of the oxygen evolution reaction is 330mV, and the full water decomposition reaction can reach 10mA/cm only by about 1.7V 2 Current density. For real seawater conditions, the full water-splitting reaction can reach 10mA/cm with a voltage of about 2.1V 2 Current density;
ni obtained in example 3 3 S 2 /Co 9 S 8 Composite nano sheet material for preparing hydrogen (H) by electrolyzing water 2 ) And oxygen (O) 2 )：
The electrocatalytic equipment adopts a three-electrode system, and comprises an electrochemical workstation, an electrolytic tank and a working electrode (NiCo hydrotalcite-like compound/Ni) 3 S 2 /Co 9 S 8 ) The counter electrode graphite rod and the reference electrode silver/silver chloride;
the electrocatalytic method adopts a linear sweep voltammetry method, and related detection parameters are as follows: the standing time is set to 5s, and the scanning speed is 50mV s -1 Scanning range is 1.0-2.0V;
the electrolyte is KOH salt solution with the concentration of 1mol L -1 ；
The electrolyte in the electrolytic cell needs to be introduced with pure O 2 To make it reach saturation state, let in O 2 The time of (2) was 30min.

Claims (4)

1. NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 The preparation method of the composite nano-sheet electrode material is characterized by comprising the following steps:
preparing nickel cobalt hydrotalcite by a hydrothermal method:
a. dissolving nickel nitrate hexahydrate, cobalt nitrate hexahydrate, ammonium fluoride and urea in deionized water according to a molar ratio of 0.5-4:1:3.6:9, and stirring for 1-2 hours by a magnetic stirrer under the condition of room temperature to form a transparent pink solution;
b. transferring the transparent pink solution obtained in the step a into a high-pressure reaction kettle lining, simultaneously vertically hanging foam nickel into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into a baking oven, setting the hydrothermal temperature to be 100-200 ℃ and the reaction time to be 4-12h;
c. after the hydrothermal reaction is finished, cooling the reaction kettle to room temperature, taking out a product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, and placing the product in a vacuum oven for drying at the temperature of 40-60 ℃ for 2-6h to obtain nano flaky nickel-cobalt hydrotalcite;
preparation of NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Composite nanosheets:
d. dissolving sodium sulfide nonahydrate into deionized water to prepare a sodium sulfide nonahydrate aqueous solution with the concentration of 0.5mmol/L-118mmol/L, and stirring the aqueous solution for 1-2h by a magnetic stirrer at room temperature to form a transparent solution;
e. transferring the transparent solution of sodium sulfide nonahydrate prepared in the step d into a high-pressure reaction kettle lining, simultaneously vertically hanging the nano flaky nickel-cobalt hydrotalcite obtained in the step c into the high-pressure reaction kettle lining, placing the high-pressure reaction kettle lining into microwave hydrothermal equipment, setting the microwave hydrothermal power to be 600-800W, and setting the temperature to be 100-160 ℃ and the reaction time to be 3-10h;
f. after the hydrothermal end, cooling the reaction kettle to room temperature, taking out the product, respectively washing with deionized water and absolute ethyl alcohol to remove surface impurities, placing the product in a vacuum oven for drying at 40-60 ℃ for 2-6h to obtain NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Composite nano-sheet electrode material.
2. The NiCo hydrotalcite/Ni according to claim 1 3 S 2 /Co 9 S 8 The preparation method of the composite nano sheet electrode material is characterized in that the loading capacity of the prepared composite nano sheet electrode material on foam nickel is 6-20mg and Ni 3 S 2 /Co 9 S 8 The composite nano-sheet vertically grows on the NiCo hydrotalcite-like nano-sheet, the thickness of the formed nano-sheet is 0.05-0.15um, and the edge length is 0.1-0.9um.
3. A NiCo hydrotalcite-like compound/Ni obtained by the process of claim 1 3 S 2 /Co 9 S 8 The application of the composite nano-sheet electrode material in preparing hydrogen and oxygen in the electrolyzed water by alkaline electrolyzed water and electrolyzed seawater.
4. Use according to claim 3, characterized by alkaline electrocatalytic properties: at 10mA cm -2 At current density, hydrogen evolution reaction overpotential is 110-180mV, at 100mA cm -2 When the current density is reached, the overpotential of the oxygen evolution reaction is 233-330mV, and the full water decomposition reaction only needs 1.4-1.7V voltage to reach 10mA/cm 2 Current density; for real seawater conditions, the full water decomposition reaction requires about 1.86-2.1V voltage, namely 10mA/cm 2 Current density.
CN202211664628.2A 2022-12-23 2022-12-23 NiCo hydrotalcite-like compound/Ni 3 S 2 /Co 9 S 8 Preparation method and application of composite nano-sheet electrode material Pending CN116334681A (en)

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