Hydrothermal synthesis method for nitrogen-doping graphene-loaded cobalt oxygen reduction reaction electrocatalyst

A technology of nitrogen-doped graphene and synthesis method, applied in circuits, electrical components, battery electrodes, etc., can solve problems such as electrical conductivity and catalytic stability defects, and achieve a simple and easy-to-control preparation method, good repeatability, high selective effect

Active Publication Date: 2017-02-22
HEFEI UNIV OF TECH
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Problems solved by technology

Transition metal compounds mainly include transition metal sulfides, transition metal oxides (including spinel type and perovskite type) and transition metal complexes (Feng Y J et al, Fuel Cells, 2000, 10(1), 77- 83; Wu Z S et al, Journal of the Americ

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  • Hydrothermal synthesis method for nitrogen-doping graphene-loaded cobalt oxygen reduction reaction electrocatalyst
  • Hydrothermal synthesis method for nitrogen-doping graphene-loaded cobalt oxygen reduction reaction electrocatalyst
  • Hydrothermal synthesis method for nitrogen-doping graphene-loaded cobalt oxygen reduction reaction electrocatalyst

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Example Embodiment

[0033] Example 1:

[0034] 1. Graphene oxide (GO) is prepared by the conventional Hummer method using graphite powder with a particle size of less than 20μm as raw material;

[0035] 2. The GO and urea were mixed and milled in a mass ratio of 1:10 and put into a 160℃ oven for nitrogen-doped heat treatment for 6 hours. After cooling, the nitrogen-doped GO was crushed and washed with deionized water, and then added to deionized water for ultrasonic dispersion The concentration is 1.5g·L in 0.5h -1 Add 0.5 times the GO mass of cobalt nitrate crystals to the dispersion, stir and disperse evenly, transfer the mixed solution to a hydrothermal reactor, and react hydrothermally at 160℃ for 12h; after cooling, open the reactor and add 15 times the GO quality of hydrazine hydrate, adjust the pH of the solution to 10 with ammonia water, seal the reactor, hydrothermally reduce the reaction at 180 ℃ for 10 hours, after the reaction liquid is cooled, use vacuum suction filtration, and wash the t...

Example Embodiment

[0038] Example 2:

[0039] 1. Graphene oxide (GO) is prepared by the conventional Hummer method using graphite powder with a particle size of less than 20μm as raw material;

[0040] 2. The GO and urea are mixed and milled in a mass ratio of 1:3, and then put into a 180℃ oven for nitrogen doping heat treatment for 4 hours. After cooling, the nitrogen doped GO is crushed and washed with deionized water, and then added to deionized water for ultrasonic dispersion The concentration is 1.5g·L in 0.5h -1 Transfer the dispersion to a hydrothermal reaction vessel, and conduct a hydrothermal reaction at 140°C for 4 hours; open the reaction vessel after cooling, adjust the pH of the solution to 10 with ammonia, add 10 times the GO mass of hydrazine hydrate and seal it The reaction kettle was subjected to hydrothermal reduction reaction at 110°C for 4 hours. After cooling, the reaction solution was filtered under reduced pressure, washed twice with deionized water and absolute ethanol, and d...

Example Embodiment

[0044] Example 3:

[0045] 1. Graphene oxide (GO) is prepared by the conventional Hummer method using graphite powder with a particle size of less than 20μm as raw material;

[0046] 2. The GO and urea are mixed and milled in a mass ratio of 1:5, then placed in a 120℃ oven for nitrogen-doped heat treatment for 24h. After cooling, the nitrogen-doped GO is crushed and washed with deionized water, and then added to deionized water for ultrasonic dispersion The concentration is 1.5g·L in 0.5h -1 Add cobalt acetate crystals of twice the GO mass to the dispersion, stir and disperse evenly, transfer the mixed solution to the hydrothermal reactor, and hydrothermally react at 200℃ for 4h; after cooling, open the reactor and add 40 times the GO quality of hydrazine hydrate, adjust the pH of the solution to 10 with ammonia water, seal the reaction kettle, and hydrothermally reduce the reaction at 140℃ for 24h. After the reaction solution is cooled, it is filtered under reduced pressure and wa...

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Abstract

The invention discloses a hydrothermal synthesis method for a nitrogen-doping graphene-loaded cobalt oxygen reduction reaction electrocatalyst. The hydrothermal synthesis method comprises the steps of fully mixing and placing GO (graphene oxide) and urea in a baking oven for nitrogen-doping thermal treatment; smashing and adding the nitrogen-doping GO into deionized water for ultrasound dispersion for 0.5 hour, transferring the obtained product to a hydrothermal reaction kettle, performing magnetic stirring for 20 minutes, adding a cobalt salt, continuing to stir for 10 minutes, and sealing the reaction kettle for hydrothermal reaction; and adding hydrazine hydrate after the hydrothermal reaction is completed, adjusting pH of a solution to be 10 with concentrated ammonia water, sealing the reaction kettle, and continuing hydrothermal reduction reaction to obtain a nitrogen-doping graphene-loaded cobalt composite material. The nitrogen-doping graphene-loaded cobalt composite material prepared according to the method is used as the oxygen reduction reaction electrocatalyst, a cyclic voltammetry reduction peak potential in 0.1M of KOH solution is -0.18V (vs.Ag/AgCl), and an initial potential is -0.1V (vs.Ag/AgCl).

Description

[0001] 1. Technical Field [0002] The invention relates to a method for synthesizing an electrocatalyst for an oxygen reduction reaction, in particular to a hydrothermal synthesis method for an electrocatalyst for an oxygen reduction reaction of nitrogen-doped graphene loaded cobalt. [0003] 2. Background technology [0004] Among the electrocatalysts for oxygen reduction reactions, the most commonly used and best catalytic activity is Pt and Pt-based metal-supported carbon composite materials. However, due to the lack of Pt resources, the high price, and the defects of catalyst particle aggregation during use, it has been studied for many years Researchers have carried out a lot of research work in reducing the cost of electrocatalysts for oxygen reduction reactions, looking for new preparation methods and new support materials, which can be roughly divided into Pt-based and non-Pt-based catalysts. [0005] The work of Pt-based catalysts is mainly based on Pt / C doping with non-preci...

Claims

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Application Information

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IPC IPC(8): H01M4/90
CPCH01M4/90H01M4/9083Y02E60/50
Inventor 翟林峰王冉孙敏
Owner HEFEI UNIV OF TECH
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