CN-121992439-A - Nickel-iron layered double hydroxide nano material doped with anions and cations as well as preparation method and application thereof

CN121992439ACN 121992439 ACN121992439 ACN 121992439ACN-121992439-A

Abstract

The invention discloses a yin-yang ion doped nickel-iron layered double hydroxide nano material and a preparation method and application thereof, belonging to the field of oxygen evolution catalysis of electrolyzed seawater. The catalytic nano material core part of the invention is to construct cation doped nickel-iron layered double hydroxide on a foam nickel substrate from bottom to top in situ, a nickel-iron layered double hydroxide nano sheet material containing vanadium doped on the foam nickel substrate is grown in situ by a hydrothermal method, the electronic structure of the catalyst can be effectively regulated by doping vanadium, and then a phosphate protecting layer is constructed on the surface of the catalyst by low-temperature phosphating, so that the active components of the catalytic material are protected, and meanwhile, the corrosion of harmful chloride ions in seawater to the catalyst is relieved. As a catalyst for the oxidation of electrolytic seawater, the catalyst has very excellent reaction activity and stability, and has important potential application value in preparing transition metal oxygen evolution electrocatalytic materials for the oxygen evolution reaction of seawater.

Inventors

FAN HUAFENG
YU JIANGANG
SU GUODONG
JIN YI
LI JIE
CHEN YONGBING
Xiang Xiujun
LIAO GUOJUN
LV CHAO

Assignees

衢州学院

Dates

Publication Date: 20260508
Application Date: 20260113

Claims (10)

1. The anion-cation doped nickel-iron layered double hydroxide nano material is characterized in that the nano material is an anion-cation doped nickel-iron layered double hydroxide nano material constructed in situ on a foam nickel substrate, and is denoted as NiFe LDH/NF, and has a nano-sheet array structure.
2. The method of claim 1, wherein the nickel-iron layered double hydroxide comprises vanadium ion doped, denoted as V-NiFe LDH/NF, to regulate the electronic structure.
3. The anion-cation doped nickel-iron layered double hydroxide nanometer material according to claim 2, wherein the nanometer electrocatalytic material comprises a phosphate anion amorphous protective layer on the crystal surface, which is denoted as V-NiFe LDH@Pi NF.
4. The anion-cation doped nickel-iron layered double hydroxide nano material according to claim 3, wherein the content of vanadium atoms in the anion-cation doped nickel-iron layered double hydroxide nano sheet electrocatalyst is 1.67at% to 3.45at%, the content of nickel atoms is 16.76at% to 22.39at%, the content of iron atoms is 8.39at% to 12.48at%, the content of phosphorus atoms is 2.59at% to 6.18at%, the content of oxygen atoms is 24.28at% to 30.68at%, and the content of carbon atoms is 33.59at% to 39.38at%.
5. The yin-yang ion doped nickel-iron layered double hydroxide nanomaterial according to any one of claims 1-4, wherein the catalyst grows on foam nickel in situ from bottom to top, and has a nano-sheet array structure, and the size of the yin-yang ion doped nickel-iron layered double hydroxide nano-sheet is 200-400 nm.
6. The method for synthesizing the anion-cation doped nickel-iron layered double hydroxide catalyst according to claim 3, which is characterized by comprising the following steps: s1, synthesizing nickel-iron layered double hydroxide doped with vanadium ions in situ on a foam nickel substrate from bottom to top by utilizing a hydrothermal method; and S2, modifying phosphate ions to the surface of the nickel-iron layered double hydroxide nano sheet by using a low-temperature phosphating method.
7. The method of synthesis according to claim 6, wherein: The specific steps of the step S1 are that foam nickel which is cleaned by hydrochloric acid, acetone and ethanol is put into a clear solution which contains a nickel source, an iron source, a vanadium source, urea and ammonium fluoride, and a hydrothermal method is adopted to prepare nickel-iron layered double hydroxide which contains vanadium ion doping on the nickel foam in situ; The specific step of the step S2 is that sodium hypophosphite monohydrate and nickel-iron layered double hydroxide doped with vanadium ions are respectively placed at the upstream and downstream of a tube furnace, and phosphate ion-modified nickel-iron layered double hydroxide catalytic material doped with vanadium ions is synthesized on the surface by utilizing a low-temperature phosphating means.
8. The synthesis method according to claim 7, wherein the hydrothermal method is performed at a synthesis temperature of 100-150 ℃ for 4-8 hours, the concentration of the solution of the vanadium source is 0.003-0.006 mol/L, the solution is provided by vanadium chloride, sodium metavanadate or ammonium metavanadate, the concentration of the solution of Ni 2+ is 0.01-0.04 mol/L, the solution is selected from Ni (NO 3 ) 2 ·6H 2 O、NiCl 2 ·6H 2 O or NiSO 4 ·7H 2 O), the concentration of the solution of Fe 3+ is 0.01-0.04 mol/L, and the solution is selected from Fe (NO 3 ) 3 ·9H 2 O、FeCl 3 ·6H 2 O or Fe 2 (SO 4 ) 3 ·9H 2 O).
9. The method of claim 6, wherein the low-temperature phosphating is carried out at a temperature of 250-350 ℃, for a period of 5-25 min, and the sodium hypophosphite monohydrate is 25-75 mg.
10. The use of the anion-cation doped nickel-iron layered double hydroxide nanomaterial of claim 1 in the production of oxygen by electrolysis of seawater.

Description

Nickel-iron layered double hydroxide nano material doped with anions and cations as well as preparation method and application thereof Technical Field The invention relates to the technical field of electrolysis seawater oxygen evolution, in particular to an anion-cation doped nickel-iron layered double hydroxide nano material and a preparation method and application thereof. Background With the continuous development of social economy, the problems of environmental pollution, energy shortage and the like are increasingly aggravated, and people are looking for lower-carbon and environment-friendly green renewable energy sources. The hydrogen energy is regarded as the clean energy with the most development prospect due to the advantages of zero carbon emission, high combustion heat value and the like, and the preparation method can be obtained through the ways of fossil fuel refining, photocatalytic cracking, water electrolysis and the like. Among them, the technology of producing hydrogen by water electrolysis is receiving extensive attention due to environmental protection, simple operation and abundant raw materials. However, shortage and maldistribution of fresh water resources worldwide severely hampers its practical use. Seawater, an inexhaustible resource on earth, is considered an alternative. However, in practical application, the method faces serious challenges, and because of the existence of abundant chloride ions (Cl- & gt 0.5M) in the seawater, chlorine Evolution Reaction (CER) of the anode is usually caused, the chlorine evolution reaction and OER are in competition reaction, harmful hypochlorite is generated in the reaction process, the anode is severely corroded, and hydrogen production by the electrolysis of the seawater is greatly hindered. Therefore, development of an electrolytic seawater oxygen evolution electrocatalyst with high activity and chlorine ion resistance is imperative. Noble metal-based catalysts have been of great interest for their excellent oxygen evolution properties, but their high cost and resource scarcity limit large-scale applications. In contrast, transition metal-based materials have a more practical prospect due to low cost and strong designability. The self-supporting electrode material represented by nickel-iron hydroxide has good catalytic activity in an alkaline electrolytic water system due to the adjustable electronic structure and large specific surface area. However, the existing researches are mainly carried out in alkaline electrolyte without chloride ions, and special design and verification for the condition of high concentration of chloride ions (Cl-) in seawater are lacking. In addition, the material is easy to generate chlorine separation competition, surface corrosion or component loss in chlorine-containing environment, so that the OER selectivity and long-term stability are obviously reduced. Therefore, the optimization of material composition and surface chemistry to improve OER activity and chlorine corrosion resistance is still a key technical problem to be solved. Disclosure of Invention The invention aims at providing an anion-cation doped nickel-iron layered double hydroxide nano material as well as a preparation method and application thereof aiming at the existing challenges. The electrocatalyst has excellent reactivity and stability, and can be used for electrolytic seawater oxidation reaction. The aim of the invention can be achieved by the following technical scheme: The nickel-iron layered double hydroxide nano material doped with anions and cations is prepared by constructing vanadium-ion doped nickel-iron layered double hydroxide on a foam nickel substrate in situ, synthesizing the nano material with phosphate anion layer protection after low-temperature phosphating, and is recorded as NiFe LDH/NF with a nano-sheet array structure. According to the scheme, the doping in the anion-cation doped nickel-iron layered double hydroxide nano sheet is denoted as V-NiFe LDH/NF, wherein vanadium ions are used for regulating and controlling the electronic structure of the nano sheet, so that the catalytic performance is improved. According to the scheme, the anion-cation doped nickel-iron layered double hydroxide nano sheet contains a phosphate anion protective layer, which is marked as V-NiFe LDH@Pi/NF, on the surface of the crystal and is used for relieving the corrosion of harmful chlorine in the process of the electrolytic seawater oxidation reaction. According to the scheme, the nickel-iron layered double hydroxide doped with anions and cations presents a nano-sheet array structure, and the size of the nano-sheet is 200-400 nm. According to the scheme, the content of vanadium atoms in the anion-cation doped nickel-iron layered double hydroxide nano-sheet electrocatalyst is 1.67at% to 3.45at%, the content of nickel atoms is 16.76at% to 22.39at%, the content of iron atoms is 8.39at% to 12.48at%, the content of phosphorus atoms is 2.59at% to