CN-121974311-A - Preparation method and application of cobalt phosphide electrocatalyst with regulatable interface water-hydrogen bond network

Abstract

The invention discloses a preparation method and application of a cobalt phosphide electrocatalyst with an interface water-hydrogen bond network controllable, and belongs to the field of electrocatalytic materials. The method takes cobalt nitrate, variable-valence metal chloride and urea as raw materials to synthesize a hydroxide precursor, and prepares the hydroxide precursor through in-situ oxidation reconstruction in the process of electrolytic water oxygen evolution reaction after simple low-temperature phosphating reaction treatment. The preparation method provided by the invention has the advantages of simplicity in operation, high efficiency, environmental friendliness, strong controllability, low cost and the like, and the prepared cobalt phosphide oxygen evolution electrocatalyst has the advantages of adjustable interface water-hydrogen bond network, high stability, excellent oxygen evolution activity and the like.

Inventors

• ZHANG FAN
• ZHANG HUI
• LI LI
• LI RUI

Assignees

• 淮南师范学院

Dates

Publication Date

20260505

Application Date

20260408

Claims (10)

1. 1. The preparation method of the cobalt phosphide electrocatalyst with the adjustable and controllable interface water-hydrogen bond network is characterized by comprising the following steps: Adding cobalt nitrate, first valence-variable metal chloride, ammonium fluoride and urea into a solvent, uniformly mixing, and fully stirring until the cobalt nitrate, the first valence-variable metal chloride, the ammonium fluoride and the urea are completely dissolved to obtain a mixed reaction solution; step 2, carrying out hydrothermal reaction on the mixed reaction liquid, and washing and drying an obtained product to obtain a cobalt hydroxide precursor; step 3, dispersing the obtained cobalt hydroxide precursor in a second valence-variable metal chloride solution, and reacting for 10-120 minutes to obtain a double valence-variable metal doped cobalt hydroxide precursor; Step 4, performing phosphating reaction on the obtained double-valence-variable metal doped cobalt hydroxide precursor and sodium hypophosphite for 2 hours at the temperature of 300-400 ℃, and cooling to obtain a cobalt phosphide electrocatalyst; and 5, placing the cobalt phosphide electrocatalyst in a potassium hydroxide solution, and carrying out oxidation reconstruction under different voltages to obtain the cobalt phosphide electrocatalyst with the interface water-hydrogen bond network being controllable.
2. 2. The method of manufacturing according to claim 1, characterized in that: in the step 1, the molar ratio of the first variable metal chloride salt to the cobalt nitrate, the ammonium fluoride and the urea is 0.05-0.2:1:2.5:5.
3. 3. The method of manufacturing according to claim 1, characterized in that: In the step 2, the hydrothermal reaction temperature is 100-160 ℃ and the reaction time is 8 hours.
4. 4. The method of manufacturing according to claim 1, characterized in that: in the step 3, the mass ratio of the second valence-variable metal chloride salt to the cobalt hydroxide precursor is 0.1-1:1.
5. 5. The method of manufacturing according to claim 1, characterized in that: The first variable metal chloride salt, the second variable metal chloride salt is selected from ferric chloride, cerium chloride, chromium chloride, vanadium chloride, tin chloride, or aluminum chloride, and the first variable metal chloride salt is different from the second variable metal chloride salt.
6. 6. The method of manufacturing according to claim 1, characterized in that: In the step 4, the mass ratio of the double-valence-variable metal doped cobalt hydroxide precursor to sodium hypophosphite is 1:20.
7. 7. The method of manufacturing according to claim 1, characterized in that: In step 5, the oxidative reconstitution is performed in a 1.0mol/L potassium hydroxide solution at a voltage of 1.0 to 1.8V.
8. 8. An interfacial water hydrogen bond network regulatable cobalt phosphide electrocatalyst prepared according to the preparation method of any one of claims 1-7.
9. 9. The use of the cobalt phosphide electrocatalyst with regulatable interface water-hydrogen bond network in electrolytic water oxygen evolution reaction of claim 8.
10. 10. The use according to claim 9, characterized in that: the cobalt phosphide electrocatalyst with the interface water-hydrogen bond network being controllable is used as an anode, a platinum sheet is used as a cathode, and Hg/HgO is used as a reference electrode to form a three-electrode system.

Description

Preparation method and application of cobalt phosphide electrocatalyst with regulatable interface water-hydrogen bond network Technical Field The invention belongs to the field of electrocatalytic materials, and particularly relates to a preparation method and application of a cobalt phosphide electrocatalyst with an interface water-hydrogen bond network controllable. Background Traditional fossil resources are gradually exhausted, energy demands are continuously rising, and the energy demands and the fossil resources are overlapped, so that the ecological environment pressure is increasingly severe. The construction of a novel energy system with clean low carbon, safety and high efficiency is quickened, and the novel energy system has become global consensus. Development of high-efficiency energy conversion technology is needed to overcome the technical problem of the key material back reaction principle, and design and preparation methods of innovative materials are needed. The hydrogen production by water electrolysis is a green and efficient energy conversion mode, and is paid attention to because of the advantages of high product purity, wide raw material sources, no carbon emission and the like. In the process of water electrolysis, oxygen Evolution Reaction (OER) involves a four-electron transfer process, and the kinetics are slow, which is a key to determining the overall energy conversion efficiency. Therefore, developing the oxygen evolution electrocatalytic material with high efficiency, stability and low cost has important significance for promoting the development of the water electrolysis hydrogen production technology. In the non-noble metal oxygen evolution catalyst, cobalt-based materials become research hot spots due to good oxygen evolution activity, structural adjustability and resource richness. In recent years, cobalt phosphide (CoP) has been widely used as an oxygen evolution electrocatalyst due to its excellent electrical conductivity and catalytic stability. Research shows that the surface interface microenvironment of the catalyst, especially the hydrogen bond network structure of the interface water molecules, has obvious influence on the adsorption behavior and reaction path of the intermediate of the oxygen evolution reaction. Interaction between reactants and active sites can be optimized by regulating and controlling an interface water-hydrogen bond network, so that catalytic efficiency is improved. However, the current regulation of the interfacial water-hydrogen bond network still lacks a simple and controllable preparation strategy. The existing method depends on complex surface modification or harsh synthesis conditions, and accurate design and repeatable construction of a hydrogen bond network structure are difficult to realize. Therefore, the cobalt phosphide electrocatalyst capable of effectively regulating and controlling the interface water-hydrogen bond network is developed, and has important theoretical value and application prospect. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a preparation method and application of a cobalt phosphide electrocatalyst with an interface water-hydrogen bond network which can be regulated. The cobalt phosphide oxygen evolution electrocatalyst prepared by the invention has the characteristics of adjustable interface water-hydrogen bond network, high stability, excellent oxygen evolution activity and the like. The invention relates to a preparation method of a cobalt phosphide electrocatalyst with an interface water-hydrogen bond network controllable, which comprises the following steps: adding cobalt nitrate, first valence-variable metal chloride, ammonium fluoride and urea into a container containing a solvent, uniformly mixing, and fully stirring until the cobalt nitrate, the first valence-variable metal chloride, the ammonium fluoride and the urea are completely dissolved to obtain a mixed reaction solution; step 2, carrying out hydrothermal reaction on the mixed reaction solution for 8 hours at the temperature of 100-160 ℃, and washing and drying the obtained product to obtain a cobalt hydroxide precursor; step 3, dispersing the obtained cobalt hydroxide precursor in a second valence-variable metal chloride solution, and reacting for 10-120 minutes to obtain a double valence-variable metal doped cobalt hydroxide precursor; Step 4, performing phosphating reaction on the obtained double-valence-variable metal doped cobalt hydroxide precursor and sodium hypophosphite for 2 hours at the temperature of 300-400 ℃, and cooling to obtain a cobalt phosphide electrocatalyst; and 5, placing the cobalt phosphide electrocatalyst in a potassium hydroxide solution, and carrying out oxidation reconstruction under different voltages to obtain the cobalt phosphide electrocatalyst with the interface water-hydrogen bond network being controllable. Wherein: in the step 1, the molar ratio of the first variable m