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CN-121976229-A - Water vapor-assisted oxygen-enriched defect iron-nickel electrocatalyst, and preparation method and application thereof

CN121976229ACN 121976229 ACN121976229 ACN 121976229ACN-121976229-A

Abstract

The invention relates to a preparation method of a steam-assisted oxygen-enriched defect iron-nickel electrocatalyst, which comprises the steps of mixing an iron source, a nickel source and graphene oxide suspension to obtain a precursor solution, carrying out hydrothermal reaction on the precursor solution to obtain a reaction product, drying the reaction product, and then sequentially carrying out high-temperature nitridation and water etching processes by adopting a chemical vapor deposition method to obtain the steam-assisted oxygen-enriched defect iron-nickel electrocatalyst. In the preparation process, the graphene oxide contains rich oxygen, so that a large number of anchoring sites are provided for the uniform dispersion of iron atoms and nickel atoms, then in the high-temperature nitridation process, the introduction of partial nitrogen is beneficial to improving the stability of the catalyst, and then a large number of oxygen elements are further introduced through the water etching process, and a large number of oxygen defect triggering lattice oxygen mechanisms are constructed at high temperature, so that the graphene oxide can cooperate with AEM mechanisms, and the active sites on the surface of the catalyst are fully utilized to improve the OER performance of the catalyst.

Inventors

  • FAN XIUJUN
  • MAO WENJIA

Assignees

  • 西安交通大学

Dates

Publication Date
20260505
Application Date
20260310

Claims (10)

  1. 1. The preparation method of the steam-assisted oxygen-enriched defect iron-nickel electrocatalyst is characterized by comprising the following steps of: S1, mixing an iron source, a nickel source and graphene oxide suspension to obtain a precursor solution, and performing hydrothermal reaction on the precursor solution to obtain a reaction product; s2, drying the reaction product, and then sequentially carrying out high-temperature nitridation and water etching processes by adopting a chemical vapor deposition method to obtain the steam-assisted oxygen-enriched defect iron-nickel electrocatalyst.
  2. 2. The preparation method of claim 1, wherein the iron in the iron source accounts for 6-12% of the mass of the graphene oxide, and the nickel in the nickel source accounts for 5-13% of the mass of the graphene oxide.
  3. 3. The method according to claim 1 or 2, wherein the iron source is ferric nitrate and the nickel source is nickel nitrate.
  4. 4. The preparation method according to claim 1, wherein in the step S1, the temperature of the hydrothermal reaction is 160-200 ℃, and the time of the hydrothermal reaction is 10-18 hours.
  5. 5. The method according to claim 1, wherein the high temperature nitriding and water etching processes performed sequentially by chemical vapor deposition in step S2 comprise the steps of performing a heating reaction in a mixed atmosphere of argon and ammonia gas, and then performing a heating reaction in a vapor atmosphere.
  6. 6. The preparation method according to claim 5, wherein in the heating reaction process under the mixed atmosphere of argon and ammonia, the reaction temperature is 600-1000 ℃, the reaction time is 1-3 hours, the gas flow rate of the argon is 100+/-50 sccm, and the gas flow rate of the ammonia is 50+/-50 sccm.
  7. 7. The method according to claim 5, wherein the reaction temperature is 600 to 1000 ℃ and the reaction time is 1 to 3 hours in the heating reaction process under the atmosphere of water vapor, and the gas flow rate of the water vapor is 20.+ -. 10 sccm.
  8. 8. The preparation method according to claim 1, wherein in the step S2, the drying treatment is a freeze-drying treatment, and the time of the freeze-drying treatment is 2-15 hours.
  9. 9. The steam-assisted oxygen-enriched defect iron-nickel electrocatalyst is characterized by being prepared by the preparation method according to any one of claims 1 to 8.
  10. 10. Use of the water vapor assisted oxygen-enriched deficient iron-nickel electrocatalyst according to claim 9 as an electrocatalyst for oxygen evolution reactions to produce oxygen.

Description

Water vapor-assisted oxygen-enriched defect iron-nickel electrocatalyst, and preparation method and application thereof Technical Field The invention belongs to the technical field of electrochemical catalysis, and particularly relates to a steam-assisted oxygen-enriched defect iron-nickel electrocatalyst, and a preparation method and application thereof. Background The technology for producing hydrogen by electrolyzing water can utilize electric energy generated by renewable energy sources (such as wind energy and solar energy) to convert and produce high-purity hydrogen, and has important roles in short-term and long-term energy storage solutions because the zero emission, flexibility and application fields of the technology are widely paid attention to by all parties. The electrocatalytic Oxygen Evolution Reaction (OER) in alkaline medium is a key step of industrial electrolytic water hydrogen production, but because the reaction has a 4e - process, the reaction involves multi-proton coupling, multi-electron transfer and O-O bond formation in four redox reaction processes, so that dynamics are slow, the electrocatalytic catalytic efficiency is low, the energy consumption is high, and the method is always a bottleneck of green hydrogen production. Conventional noble metal catalysts (e.g., ruO 2,IrO2, pt, etc.) while exhibiting high efficiency in this process, have limited their use on a large scale due to poor stability in alkaline aqueous cracking environments, high cost, and scarcity, and are becoming a serious problem to be solved for commercial viability and environmental friendliness in OER research. Therefore, development of low cost, high efficiency, non-noble metal electrocatalysts to accelerate OER reactions is urgent. In recent years, the graphene-based non-noble metal electrocatalyst has the advantages of low cost, wide raw material source, easy acquisition, proper atomic and electronic structure and adjustable chemical reactivity, and great potential. However, the single metal iron-based catalyst has the problems of insufficient active sites, poor surface site utilization, low conductivity, poor intrinsic activity and the like. Currently, graphene-based diatomic catalysts formed by doping of iron-nickel exhibit better performance than single iron due to the synergistic effect between the components. However, the surface sites formed by directly doping the graphene with iron-nickel metal have fewer active sites due to insufficient surface defects, which makes the catalyst incapable of efficiently performing OER reaction and limits the use of such catalysts. Therefore, the oxygen enrichment defect is increased after the iron-nickel metal is doped on the surface of the graphene through regulation and control, and the method is a problem to be solved in the current preparation of the high-activity OER catalyst. Disclosure of Invention The invention aims to provide a steam-assisted oxygen-enriched defect iron-nickel electrocatalyst, and a preparation method and application thereof, which are used for solving the technical problem of how to maximally utilize surface sites as active sites to improve a transition metal-based OER catalyst in the existing preparation method; In order to achieve the above purpose, the invention adopts the following technical scheme: A steam-assisted oxygen-enriched defect iron-nickel electrocatalyst, a preparation method and application thereof, comprises the following steps: S1, mixing an iron source, a nickel source and graphene oxide suspension to obtain a precursor solution, and performing hydrothermal reaction on the precursor solution to obtain a reaction product; s2, drying the reaction product, and then sequentially carrying out high-temperature nitridation and water etching processes by adopting a chemical vapor deposition method to obtain the steam-assisted oxygen-enriched defect iron-nickel electrocatalyst. Preferably, the iron in the iron source accounts for 6-12% of the mass of the graphene oxide, and the nickel in the nickel source accounts for 5-13% of the mass of the graphene oxide. Preferably, the iron source is ferric nitrate nonahydrate and the nickel source is nickel nitrate hexahydrate. Preferably, in the step S1, the temperature of the hydrothermal reaction is 160-200 ℃, and the time of the hydrothermal reaction is 10-18 hours. Preferably, in the step S2, the high-temperature nitriding and water etching processes are sequentially performed by adopting a chemical vapor deposition method, wherein the heating reaction is performed under a mixed atmosphere of argon and ammonia, and then the heating reaction is performed under a steam atmosphere. Preferably, in the heating reaction process under the mixed atmosphere of argon and ammonia, the reaction temperature is 600-1000 ℃, the reaction time is 1-3 h, the gas flow of the argon is 100+/-50 sccm, and the gas flow of the ammonia is 50+/-50 sccm. Preferably, in the heating reaction process under the atmos