阅读说明：本技术 一种多孔NiS2纳米片的制备方法及NiS2材料 (Preparation method of porous NiS2 nanosheet and NiS2 material ) 是由 徐冬 孟瑞红 高文君 孙振新 郭桦 陈保卫 高腾飞 杨阳 于 2019-09-03 设计创作，主要内容包括：本发明提供一种多孔NiS_2纳米片制备方法及一种NiS_2材料,该NiS_2材料具有疏松多孔的纳米片结构。该制备方法采用含镍化合物前驱体的方法制备,进一步通过硫化处理,由最初比较平整的纳米片变为多孔疏松的纳米片状结构。该材料可以用于电催化析氧反应催化剂。本发明的优点是该制备方法操作简单,产物纯度高,结晶好,NiS_2为多孔疏松的纳米片状结构,有利于催化反应过程中反应物与催化剂的接触,有利于反应过程中反应物和产物的传输,同时疏松多孔的纳米片结构提供了更多的催化活性位点,从而有效地提高了催化活性。该材料在析氧反应中具有较好的催化活性和催化稳定性,可作为新型催化剂用于电解水析氧反应。(The invention provides a preparation method of a porous NiS2 nano sheet and a NiS2 material, wherein the NiS2 material has a loose and porous nano sheet structure. The preparation method adopts a method of a nickel-containing compound precursor for preparation, and further changes an initial relatively flat nano sheet into a porous loose nano sheet structure through vulcanization treatment. The material can be used as an electro-catalytic oxygen evolution reaction catalyst. The preparation method has the advantages that the preparation method is simple to operate, the product is high in purity and good in crystallization, NiS2 is in a porous and loose nano sheet structure, contact between reactants and a catalyst in a catalytic reaction process is facilitated, transmission of the reactants and the product in the reaction process is facilitated, and meanwhile, more catalytic active sites are provided by the porous and loose nano sheet structure, so that the catalytic activity is effectively improved. The material has better catalytic activity and catalytic stability in oxygen evolution reaction, and can be used as a novel catalyst for electrolysis water oxygen evolution reaction.)

1. A preparation method of a porous NiS2 nanosheet is characterized in that the material structure is a nano flaky structure, the nanosheet is provided with a porous structure, and the synthesis method adopts a method of preparing a nickel-containing compound precursor, and comprises the following steps:

1) Synthesis of nickel-containing compounds: adding 1-3 g of triblock copolymer P123 (molecular weight is 5800) into a mixed solution containing acid and alcohol, completely dissolving, adding 0.01-0.10 mol of nickel salt, stirring to completely dissolve, heating the mixed solution, volatilizing the solvent for self-assembly for 2-6 h, cooling, cleaning, drying, and roasting the obtained product to obtain a nickel-containing compound;

2) And (3) vulcanization treatment: roasting the nickel-containing compound and sulfur in the step 1), and cooling to obtain the NiS2 catalyst material.

2. A porous NiS2 nanosheet preparation method according to claim 1, wherein the nickel salt used is one or more of nickel chloride, nickel sulfate or nickel nitrate hexahydrate.

3. A preparation method of a porous NiS2 nanosheet according to claim 1, wherein in step 1), the acid used is one or more of nitric acid, concentrated nitric acid, sulfuric acid or hydrochloric acid, and the amount used is 1-5 mL.

4. A preparation method of a porous NiS2 nanosheet according to claim 1, wherein in step 1), the alcohol used is one or more of ethanol, propanol, isopropanol or n-butanol, and the amount used is 10-20 mL.

5. a porous NiS2 nanosheet preparation method according to claim 1, wherein in step 1), 1-3 g of triblock copolymer P123 (molecular weight 5800) is added to a mixed solution containing an acid and an alcohol and completely dissolved at room temperature or 30-60 ℃.

6. The preparation method of a porous NiS2 nanosheet according to claim 1, wherein in step 1), the mixed solution is heated to volatilize the solvent from the self-assembly temperature of 100-160 ℃, cooled to room temperature, washed with ethanol, centrifuged, and dried in air, vacuum or frozen state.

7. The preparation method of the porous NiS2 nanosheets of claim 1, wherein in step 1), the dried product is gradually heated and roasted at a rate of 2-10 ℃/min, and the roasting temperature is 100-300 ℃.

8. A porous NiS2 nanosheet preparation method according to claim 1, wherein in step 2), the nickel-containing compound and sulfur powder are placed in an environment isolated from the outside.

9. A porous NiS2 nanosheet preparation method according to claim 8, wherein in step 2), the nickel-containing compound and sulfur powder are surrounded by an inert gas or are in a vacuum.

10. a porous NiS2 nanosheet preparation method according to claim 9, wherein in step 2), the inert gas is one or more of nitrogen, helium, and argon.

11. The method as claimed in claim 10, wherein the inert gas is a continuous gas, 150-250 mg of sulfur powder is mixed with the nickel-containing compound, and 500-3000 mg of sulfur powder is disposed upstream of the flow of the gas compared to the nickel-containing compound.

12. A porous NiS2 nanosheet preparation method according to claim 11, wherein the flow rate of the continuously flowing inert gas is 20-30 scc/min.

13. A method for preparing porous NiS2 nanosheets according to any one of claims 1 to 12, wherein in step 2), the temperature is gradually increased to 200-500 ℃ at a temperature increase rate of 1-5 ℃/min, and the baking time is 1-5 h.

14. The NiS2 nano material is characterized in that the NiS2 nano material is in a porous NiS2 nano sheet structure.

Technical Field

The invention belongs to the technical field of porous materials and catalysis, and particularly relates to a preparation method of a porous NiS2 nanosheet, a NiS2 material and a catalyst.

Technical Field

Hydrogen production by water electrolysis is a clean energy conversion process and energy storage technology, and the water electrolysis comprises two reactions of Hydrogen Evolution (HER) and Oxygen Evolution (OER), but the reaction needs to be effectively carried out under the action of a catalyst. As an important half-reaction in the electrolysis of water, oxygen evolution, involving the transfer of 4 electrons and the formation of oxygen-oxygen bonds, is a relatively slow reaction and is therefore critical to the water electrolysis reaction rate. At present, the most effective catalysts in the oxygen evolution reaction are two noble metal catalysts, namely RuO2 and IrO2, but the noble metal catalysts are poor in resources and expensive, so that the large-scale application of the catalysts in the industry is limited. There is therefore an urgent need to develop an effective catalyst based on inexpensive metals.

Disclosure of Invention

The invention aims to provide a preparation method of a porous NiS2 nanosheet for the technical analysis, so that an effective catalyst is provided for an electrocatalytic reaction, and the product is uniform in morphology and structure, high in purity, good in crystallinity, high in activity and simple in preparation method.

The invention provides a preparation method of a porous NiS2 nano sheet, which comprises the following steps:

(1) The method comprises the following steps:

1) Synthesis of nickel-containing compounds: adding 1-3 g of triblock copolymer P123 (molecular weight is 5800) into a mixed solution containing acid and alcohol, completely dissolving at a certain temperature, adding 0.01-0.10 mol of nickel salt to completely dissolve the nickel salt, heating the mixed solution at a certain temperature, volatilizing the solvent for self-assembly for 2-6 h, cooling to room temperature, cleaning, drying, and roasting the product to obtain a nickel-containing compound;

2) and (3) vulcanization treatment: roasting the nickel-containing compound and the sulfur powder in the step 1) at a certain temperature, and cooling to room temperature to obtain the NiS2 catalyst material.

(2) The preparation method of the porous NiS2 nanosheet, as described in (1), wherein the nickel salt used is nickel chloride, nickel sulfate or nickel nitrate hexahydrate.

(3) The porous NiS2 nanosheet preparation method according to (1) to (2), wherein, in step 1), the acid is: one or more of nitric acid, concentrated nitric acid, sulfuric acid or hydrochloric acid, and the preferable dosage is 1-5 mL.

(4) The porous NiS2 nanosheet preparation method according to (1) to (3), wherein, in step 1), the alcohol is: one or more of ethanol, propanol, isopropanol or n-butanol, preferably 10-20 mL.

(5) the preparation method of the porous NiS2 nanosheets described in (1) to (4), wherein in step 1), 1 to 3g of a triblock copolymer P123 (molecular weight 5800) is added to a mixed solution containing an acid and an alcohol, and dissolved at a temperature: room temperature or other temperatures, preferably 30 to 60 ℃.

(6) The preparation method of the porous NiS2 nanosheet according to (1) to (5), wherein in the step 1), the temperature at which the mixed solution is heated and the solvent volatilizes and self-assembles is as follows: reacting at 100-160 ℃, cooling to room temperature, washing with ethanol, performing centrifugal separation, and drying in an air environment, wherein the drying environment is preferably selected from the following conditions: drying in a vacuum state; the drying temperature is preferably 30-60 ℃.

(7) The preparation method of the porous NiS2 nanosheets, according to the steps (1) to (6), wherein in the step 1), the temperature of the dried product is gradually increased at a certain temperature increasing rate during roasting, preferably the temperature increasing rate is 2-10 ℃/min, and the roasting temperature is 100-300 ℃.

(8) The preparation method of the porous NiS2 nanosheet according to (1) to (7), wherein in step 2), the nickel-containing compound and the sulfur powder are placed in an environment isolated from the outside.

(9) the method for preparing porous NiS2 nanosheets according to (1) to (8), wherein in step 2), the nickel-containing compound and the sulfur powder are surrounded by an inert gas or are in a vacuum.

(10) The preparation method of the porous NiS2 nanosheet according to (1) to (9), wherein in step 2), the inert gas is one or more of nitrogen, helium and argon.

(11) The porous NiS2 nanosheet preparation method described in (1) to (10), wherein the inert gas is a continuously flowing gas, 150-250 mg of sulfur powder is mixed with the nickel-containing compound, and 500-3000 mg of sulfur powder is placed upstream in the gas flow direction compared to the nickel-containing compound.

(12) The preparation method of the porous NiS2 nanosheets as described in (1) to (11), wherein the flow rate of the continuously flowing inert gas is 20-30 scc/min.

(13) The preparation method of the porous NiS2 nanosheets described in (1) to (12), wherein in the step 2), the temperature is gradually increased at a certain temperature increasing rate, preferably the temperature increasing rate is 1-5 ℃/min, the temperature is gradually increased to 200-500 ℃, and preferably the baking temperature is 250-400 ℃.

The invention further provides a NiS2 nano material, which is characterized in that the NiS2 nano material is a porous NiS2 nano sheet.

The nickel sulfide shows good hydrogen or oxygen evolution catalytic performance in the water electrolysis process, and the cost is relatively low, so that the catalysts with various shapes and structures and different components are widely developed and used as water electrolysis reaction catalysts. In order to improve the catalytic activity and catalytic stability of the catalyst, some catalysts with special morphological structures and porous structures are designed and synthesized.

The NiS2 nanosheet material with the porous loose structure exposes more catalytic active sites, and the structure is favorable for contact of reactants and the catalytic active sites, is favorable for substance transmission of the reactants and products in the reaction process, and is favorable for improving the catalytic activity of the catalyst. Therefore, the development of the porous NiS2 nanosheet material has very important application value and theoretical significance.

The invention has the advantages that: NiS2 is a porous and loose nano sheet structure, is beneficial to contact of reactants and a catalyst and material transmission, and simultaneously provides more catalytic active sites for the loose nano sheet structure, thereby effectively improving the catalytic activity. The product has high purity, activity and crystallinity, and simple preparation method, has better catalytic activity and catalytic stability in oxygen evolution reaction, and has practical significance and important value in the fields of developing novel oxygen evolution catalysts and the like.

Drawings

Fig. 1 is an X-ray diffraction pattern (XRD pattern) of a porous NiS2 nanosheet prepared by a method for preparing a porous NiS2 nanosheet according to embodiment 1 of the present invention.

FIG. 2 is a Scanning Electron Microscope (SEM) image of a nickel-containing compound before vulcanization treatment by a porous NiS2 nanosheet preparation method of the present invention.

Fig. 3 is a Scanning Electron Microscope (SEM) image of a porous NiS2 nanosheet prepared by a method for preparing a porous NiS2 nanosheet of example 1 of the present invention.

Fig. 4 is a Transmission Electron Microscope (TEM) image of a porous NiS2 nanosheet prepared by a method for preparing a porous NiS2 nanosheet of example 1 of the present invention.

FIG. 5 is an LSV (stress relief volume) chart of oxygen evolution performance test of a porous NiS2 nanosheet prepared by the preparation method of the porous NiS2 nanosheet in embodiment 1 of the invention

Fig. 6 is a tafel diagram of an oxygen evolution performance test of a porous NiS2 nanosheet prepared by a preparation method of the porous NiS2 nanosheet in embodiment 1 of the present invention.

Fig. 7 is an LSV diagram before and after 1000 cyclic voltammetry scans (CV) when a porous NiS2 nanosheet prepared by a porous NiS2 nanosheet preparation method of example 1 of the present invention is used as a catalyst.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.