CN-121976216-A - Preparation method of double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on anion partial filling oxygen vacancy strategy

CN121976216ACN 121976216 ACN121976216 ACN 121976216ACN-121976216-A

Abstract

A preparation method of a double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on an anion part filling oxygen vacancy strategy relates to a preparation method of an oxygen evolution reaction spinel oxide electrocatalyst. The method aims to solve the technical problems of low catalytic efficiency and unstable structure of the existing pure spinel oxide. The preparation method comprises the steps of preparing a self-supporting spinel oxide electrode material, preparing a self-supporting oxygen vacancy enrichment type spinel oxide electrode material, and preparing a self-supporting oxygen vacancy partial anion filling catalyst. The prepared Co 3 O 4 -V O -S/NF catalyst has the overpotential as low as 301 mV at the current density of 50 mA cm ‑2 in 1.0M KOH, can stably run for more than 120 hours, and can be used in the field of hydrogen production by water electrolysis.

Inventors

XU PING
LIANG RANRAN

Assignees

哈尔滨工业大学

Dates

Publication Date: 20260505
Application Date: 20260126

Claims (8)

1. The preparation method of the double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on the strategy of filling oxygen vacancies in the anion part is characterized by comprising the following steps: 1. The preparation method of the spinel oxide/NF comprises the steps of weighing metal nitrate and urea according to the stoichiometric ratio of the spinel oxide, adding the metal nitrate and urea into a solvent, stirring uniformly to form a solution, transferring the solution into a polytetrafluoroethylene lining autoclave, immersing the cleaned foam nickel into the solution in the autoclave, sealing the autoclave, placing the autoclave into an oven with the temperature of 100-130 ℃ for 5-10 hours for reaction, cooling, washing and drying to obtain a precursor, heating the precursor to 300-400 ℃ in a high-temperature furnace, and calcining for 3-4 hours to obtain the spinel oxide/NF; 2. The preparation of the oxygen vacancy enrichment type spinel oxide comprises the steps of immersing spinel oxide/NF into NaBH 4 solution with the concentration of 0.1M, keeping 30min for reduction, then washing with deionized water, and drying to obtain the oxygen vacancy enrichment type spinel oxide; 3. The preparation of the oxygen vacancy partial anion filling type catalyst comprises the steps of placing oxygen vacancy enrichment spinel oxide and an anion source in a tube furnace, placing the anion source at the upstream of an air flow, heating to 200-250 ℃ at a heating rate of 5-10 ℃ min -1 under an argon atmosphere, keeping for 2-3 hours, performing heat treatment, cooling, washing, and freeze-drying, wherein the spinel oxide electrocatalyst is based on a double-mechanism oxygen evolution reaction of an anion partial filling oxygen vacancy strategy.
2. The method for preparing a dual-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on an anionic partial filling oxygen vacancy strategy according to claim 1, wherein the spinel oxide in step one is Co 3 O 4 、ZnCo 2 O 4 、CoCr 2 O 4 、CoMn 2 O 4 、MnCo 2 O 4 、NiMn 2 O 4 or Fe 3 O 4 .
3. The method for preparing the bipolar oxygen evolution reaction spinel oxide electrocatalyst based on the anion partial filling oxygen vacancy strategy according to claim 1 or 2, wherein the solvent is water when the spinel oxide is Co 3 O 4 、ZnCo 2 O 4 in the step one, and the solvent is ethanol when the spinel oxide is Fe 3 O 4 .
4. The method for preparing the double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on the anion partial filling oxygen vacancy strategy according to claim 1 or 2, wherein the drying in the second step is drying at a temperature of 60 ℃ for 20 to 24 hours.
5. The method for preparing the double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on the anion partial filling oxygen vacancy strategy according to claim 1 or 2, wherein the anion source S powder or NH 4 F in step three is S 2- source and NH 4 F is F - source.
6. The method for preparing the double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on the anion partial filling oxygen vacancy strategy according to claim 1 or 2, wherein in the third step, for the oxygen vacancy enrichment spinel oxide with the mass of 250 mg, the amount of the anion source S powder is 20-60 mg.
7. The method for preparing a bipolar oxygen evolution reaction spinel oxide electrocatalyst based on an anionic partial fill oxygen vacancy strategy according to claim 1 or 2, wherein the washing in step three is performed 3 times each with ethanol and deionized water in sequence.
8. The method for preparing the double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on the anion partial filling oxygen vacancy strategy according to claim 1 or 2, wherein the constant temperature drying in the step three is performed at a temperature of 60 ℃ for 12 to 24 hours.

Description

Preparation method of double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on anion partial filling oxygen vacancy strategy Technical Field The invention belongs to the field of electrocatalysis, and particularly relates to a preparation method of an oxygen evolution reaction spinel oxide electrocatalyst. Background In recent years, the hydrogen production by water electrolysis is considered to be one of important ways for realizing clean energy storage and conversion because of being capable of converting renewable electric energy into high-purity hydrogen energy and having zero carbon emission potential. However, the oxygen evolution reaction (oxygen evolution reaction, OER) occurring at the anode during electrolysis of water significantly limits the overall energy efficiency and increases the cost of hydrogen production due to slow kinetics and higher overpotential. Whereas the OER electrocatalyst currently in common use is a noble metal IrO 2/RuO2 material and a spinel oxide. The Oxygen Evolution Reaction (OER) in pure spinel oxides such as Co 3O4 is often limited by a multi-step Adsorbate Evolution Mechanism (AEM), with slow kinetics. While lattice oxygen mediated mechanisms (LOMs) provide faster kinetics, uncontrolled oxygen loss often results in structural instability, limiting its practical application. Disclosure of Invention The invention aims to solve the technical problems of low catalytic efficiency and unstable structure of the existing pure spinel oxide, and provides a preparation method of a double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on an anion partial filling oxygen vacancy strategy, the invention selectively incorporates anions such as S 2- into oxygen vacancies of spinel oxide (such as Co 3O4) nanowire arrays through an 'oxygen vacancy-anion partial filling' strategy, and simultaneously enhances AEM channels and activates lattice oxygen, thereby realizing dual-mechanism OER catalysis with faster kinetics and higher structural stability. The preparation method of the double-mechanism oxygen evolution reaction spinel oxide electrocatalyst based on the anion partial filling oxygen vacancy strategy comprises the following steps: 1. The preparation method of the spinel oxide/NF comprises the steps of weighing metal nitrate and urea according to the stoichiometric ratio of the spinel oxide, adding the metal nitrate and urea into a solvent, stirring uniformly to form a solution, transferring the solution into a polytetrafluoroethylene lining autoclave, immersing the cleaned foam nickel into the solution in the autoclave, sealing the autoclave, placing the autoclave into an oven with the temperature of 100-130 ℃ for 5-10 hours for reaction, cooling, washing and drying to obtain a precursor, heating the precursor to 300-400 ℃ in a high-temperature furnace, and calcining for 3-4 hours to obtain the spinel oxide/NF; 2. Preparing oxygen vacancy enriched spinel oxide (V O)/NF, namely immersing the spinel oxide/NF into NaBH 4 solution with the concentration of 0.1M for 30 min reduction, then washing with deionized water, and drying to obtain the oxygen vacancy enriched spinel oxide (V O)/NF; 3. Oxygen vacancy-partial anion filled catalyst (V O -X)/NF preparation: Placing the oxygen vacancy enriched spinel oxide and an anion source in a tube furnace, placing the anion source in the upstream of the air flow, heating to 200-250 ℃ at the heating rate of 5-10 ℃ min -1 under the argon atmosphere, keeping for 2-3 hours, performing heat treatment, cooling, washing, and freeze-drying, wherein the spinel oxide electrocatalyst is a double-mechanism oxygen evolution reaction based on the strategy of filling oxygen vacancies in the anion part. Still further, the spinel oxide described in step one is Co3O4、ZnCo2O4、CoCr2O4、CoMn2O4、MnCo2O4、NiMn2O4 or Fe 3O4. Further, the solvent for the spinel oxide Co3O4、ZnCo2O4、CoCr2O4、CoMn2O4、MnCo2O4、NiMn2O4, in the first step is water, the spinel oxide is Fe 3O4, and the solvent is ethanol; further, the drying in the second step is performed at a temperature of 60 ℃ for 20-24 hours. Further, the anion source S powder or NH 4 F in the third step, wherein S powder is S 2- source and NH 4 F is F - source; In the third step, for oxygen vacancy enrichment spinel oxide (V O)/NF with the mass of 250 mg, the dosage of the S powder of the anion source is 20-60 mg, and the S powder is used for regulating and controlling the filling quantity of the S element. Further, the washing in the third step is to wash with ethanol and deionized water 3 times each in sequence. Further, the constant temperature drying in the third step is carried out for 12-24 hours under the condition that the temperature is 60 ℃. The application proposes a specific strategy of 'oxygen vacancy-anion partial filling' to regulate the local structure and electronic state of spinel oxide. The dual-mechanism oxygen evolution reaction spinel oxide electrocatalyst b