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CN-121976240-A - Electrocatalyst for catalyzing hydrogen evolution and preparation method thereof

CN121976240ACN 121976240 ACN121976240 ACN 121976240ACN-121976240-A

Abstract

The invention discloses an electrocatalyst for catalyzing hydrogen evolution and a preparation method thereof, wherein a NiS/WS 2 heterostructure is generated on carbon cloth through hydrothermal reaction, and then nitrogen doping is carried out on the heterostructure through high Wen Niaosu annealing, so that a three-dimensional flower-ball-shaped nitrogen doped NiS/WS 2 /CC composite material is obtained. The nitrogen doping strategy is combined with heterostructure design to obtain the composite material with the three-dimensional porous structure, the composite material is beneficial to the exposure of active sites and the rapid transfer of electrons, the doping of nitrogen introduces additional catalytic active sites, the overall electrocatalytic performance of the material can be synergistically improved, the raw materials are low in cost, the preparation flow is simple, a surfactant and complex equipment are not needed in the preparation process, and the mass production is facilitated.

Inventors

  • TANG JING
  • HUANG XINGQIN
  • JIANG HAISHUN

Assignees

  • 福州大学

Dates

Publication Date
20260505
Application Date
20260206

Claims (9)

  1. 1. The electrocatalyst for catalyzing hydrogen evolution is characterized in that the electrocatalyst is formed by generating a NiS/WS 2 heterostructure on carbon cloth through hydrothermal reaction, and then carrying out nitrogen doping on the NiS/WS 2 through high Wen Niaosu annealing to obtain a three-dimensional flower-ball-shaped nitrogen doped NiS/WS 2 /CC composite material.
  2. 2. A process for preparing an electrocatalyst according to claim 1, comprising the steps of: (1) Adding a hydrochloric acid solution into a solution of sodium tungstate dihydrate, adding oxalic acid, ammonium sulfate, thioacetamide, nickel nitrate hexahydrate and carbon cloth, stirring for 30 min at 50 ℃, transferring the mixed solution and the carbon cloth into a reaction kettle for hydrothermal reaction, and cooling to room temperature; (2) Taking out the reacted carbon cloth, washing with deionized water to remove black powder on the surface, washing with ethanol for three times, and drying overnight at 60 ℃ to obtain the carbon cloth loaded with the NiS/WS 2 heterostructure; (3) And (3) placing urea on the upper half part of the strip-shaped magnetic boat, covering the long-shaped magnetic boat by using a cover, transversely placing the carbon cloth loaded with the NiS/WS 2 heterostructure obtained in the step (2) on the lower half part of the magnetic boat, transversely placing the magnetic boat in the middle of a tube furnace, introducing nitrogen, performing heating reaction, and cooling to room temperature to obtain the nitrogen-doped NiS/WS 2 /CC composite material.
  3. 3. The method for preparing an electrocatalyst according to claim 2, wherein the hydrochloric acid solution is added in the step (1) in such an amount that the pH of the solution is 1.2.
  4. 4. The method of preparing an electrocatalyst according to claim 2, wherein the mass ratio of sodium tungstate dihydrate, oxalic acid, ammonium sulfate, thioacetamide and nickel nitrate hexahydrate used in step (1) is 1:1.21:3:1.28:0.38.
  5. 5. The method for preparing an electrocatalyst according to claim 2, wherein the carbon cloth in step (1) is soaked in aqua regia for 2 hours before use, and then calcined at 400 ℃ for 2 hours in an air atmosphere.
  6. 6. The method for preparing an electrocatalyst according to claim 2, wherein the hydrothermal reaction in step (1) is performed at a temperature of 200 ℃ for a time of 24 h.
  7. 7. The method of preparing an electrocatalyst according to claim 2, wherein the mass ratio of urea used in step (3) to carbon cloth supporting the NiS/WS 2 heterostructure is 1:0.2558.
  8. 8. The method for preparing an electrocatalyst according to claim 2, wherein the heating reaction in step (3) is carried out at a temperature increase rate of 5℃per minute, a reaction temperature of 500℃and a reaction time of 2h ℃.
  9. 9. Use of the electrocatalyst according to claim 1 for electrocatalytic hydrogen evolution.

Description

Electrocatalyst for catalyzing hydrogen evolution and preparation method thereof Technical Field The invention belongs to the technical field of electrocatalytic materials, and particularly relates to a nitrogen-doped NiS/WS 2/CC efficient electrocatalyst, and a preparation method and application thereof. Background As one of renewable energy sources, hydrogen energy possesses a sufficiently strong competitiveness. The acquisition of hydrogen by electrocatalytic hydrolysis is a very promising approach for hydrogen production. However, at present, the design and preparation of the economic, efficient and stable non-noble metal type electrocatalyst are always a key step limiting the practical application of the electrocatalyst. In the process of searching for an electrochemical hydrogen evolution reaction catalyst which is efficient, stable and low in price, transition Metal Sulfide (TMDs) is a hot spot of current scientific research due to the unique electronic configuration and excellent physicochemical properties. At present, molybdenum disulfide hydrogen evolution catalyst is considered as one of catalysts with good development prospect, and the free energy of hydrogen atom adsorption at the edge of MoS 2 is very close to that of metal Pt, so that MoS 2 is possible to be used as an effective hydrogen evolution electrocatalyst. WS 2 and MoS 2 have similar hexagonal close-packed layered structures, but WS 2 has a larger interlayer spacing than MoS 2, and WS 2 has better thermal stability than MoS 2, exhibiting good catalytic activity in catalyzing HER reactions. Thus, WS 2 material has received wide attention from scholars around the world in recent years. However, WS 2 still has some problems as an electrocatalyst. The Van der Waals force between the first WS 2 layers is easy to cause a large amount of agglomeration, the number of active sites is reduced, and thus the electrocatalytic activity is reduced, the second WS 2 is used as a semiconductor, the poor conductivity also limits the occurrence of catalytic reaction, and the third WS 2 is complex in preparation process flow, high in cost and difficult to popularize and use on a large scale. To solve the above problems, the present invention devised to increase the center density of the active site of WS 2 bulk and improve the bulk conductivity of WS 2 to increase the electrocatalytic hydrogen production performance of WS 2. The NiS has rich reserves, is easy to prepare, has good catalytic performance and good conductivity in Hydrogen Evolution Reaction (HER), and can promote electron transfer by constructing a heterostructure with WS 2, thereby remarkably improving the specific surface area and the exposure degree of active sites. In addition, the introduction of nitrogen atoms not only remarkably improves the conductivity of the material and quickens the electron transfer rate, but also can accurately adjust the electronic structure of the catalyst and optimize the adsorption energy of hydrogen atoms to be close to a thermal neutral state, thereby improving the catalytic activity. Disclosure of Invention The invention aims to overcome the defects of the prior art, provide an electrocatalyst for electrocatalytic hydrogen evolution reaction with high activity, high stability and low cost, and provide a method for preparing the catalyst, which is simple in process and environment-friendly. In order to achieve the above purpose, the invention adopts the following technical scheme: The invention aims to protect an electrocatalyst for catalyzing hydrogen evolution, which is characterized in that a NiS/WS 2 heterostructure is generated on carbon cloth through hydrothermal reaction, and then nitrogen doping is carried out on the NiS/WS 2 through high Wen Niaosu annealing, so that a three-dimensional flower-ball-shaped nitrogen doped NiS/WS 2/CC composite material is obtained, and the electrocatalyst is a three-dimensional microsphere formed by winding a large number of one-dimensional nanowires and has a hierarchical porous characteristic. The second object of the present invention is to protect the process for preparing the electrocatalyst, comprising the steps of: (1) Adding a hydrochloric acid solution into a solution of sodium tungstate dihydrate, adding oxalic acid, ammonium sulfate, thioacetamide, nickel nitrate hexahydrate and carbon cloth, stirring for 30 min at 50 ℃, transferring the mixed solution and the carbon cloth into a reaction kettle for hydrothermal reaction, and cooling to room temperature; (2) Taking out the reacted carbon cloth, washing with deionized water to remove black powder which is not adhered to the surface, washing with ethanol for three times, and drying overnight at 60 ℃ to obtain the carbon cloth loaded with the NiS/WS 2 heterostructure; (3) And (3) placing urea on the upper half part of the strip-shaped magnetic boat, covering the long-shaped magnetic boat by using a cover, transversely placing the carbon cloth loaded with the