Nitrogen-doped grapheme and preparation method

Abstract

The invention discloses nitrogen-doped grapheme and a preparation method. The method comprises the following steps: preparing graphene oxide; adding deionized water to graphene oxide, carrying out ultrasound treatment and centrifugation to obtain a graphene oxide dispersion, adding urea I into the graphene oxide dispersion, carrying out ultrasound treatment, and then placing in a reaction kettle to obtain nitrogen-doped grapheme I, wherein the reaction temperature is 160 DEG C and the reaction time lasts for 3 hours; adding melamine to absolute ethyl alcohol to obtain a mixture, mixing the mixture with the graphene oxide dispersion, then placing in a high pressure reaction kettle to obtain nitrogen-doped grapheme II, wherein the reaction temperature is 180 DEG C and the reaction time lastsfor 8 hours; mixing the graphene oxide dispersion, calcium chloride and oxalic acid powder in an ultrasound treatment manner, dissolving thioacetamide in deionized water, mixing the two in the ultrasound treatment manner to obtain a mixture, vibrating the mixture in the ultrasound treatment manner for 1 hour, and heating by an electromagnetic furnace to obtain nitrogen-doped grapheme III, whereinthe reaction temperature is 80 DEG C and the reaction time lasts for 6 hours. The nitrogen-doped graphene prepared according to the preparation method provided in the invention has the advantages that the quality is relatively high, defects are reduced, and the comprehensive performance of the nitrogen-doped graphite is improved.

Description

technical field [0001] The invention relates to the technical field of inorganic non-metallic materials, in particular to a nitrogen-doped graphene and a preparation method thereof. Background technique [0002] Due to its excellent properties such as high specific surface area, high strength, high thermal conductivity and good electrical conductivity, graphene has been widely used in many fields, such as new energy, catalysts and biomedicine. The surface of graphene with a complete structure is inert, and the general method is to combine graphene with other elements or materials to obtain good comprehensive properties. [0003] Chemical element doping is one of the more effective ways to improve the properties of graphene. At present, the methods for preparing nitrogen-doped graphene mainly include: (1) chemical vapor deposition method, which is to make the gaseous precursor react on the substrate to form a thin film. This method needs to use a metal catalyst, separate the...

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Problems solved by technology

At present, the methods for preparing nitrogen-doped graphene mainly include: (1) chemical vapor deposition method, which is to make the gaseous precursor react on the substrate to form a thin film. This method needs to use a metal catalyst, separate the metal catalyst and nitrogen doping Graphene is relatively difficult and the process is more complicated; (2) nitrogen-containing precursor conversion method, which is to mix nitrogen-containing substances with transition metal compound catalysts, react at high temperature, and obtain nitrogen-doped graphene after removing metal compounds. The metal catalyst used in this method will generate metal carbides, which are difficult to completely remove and affect the later use; (3) graphene oxide nitrogen doping method, which uses graphene oxide as raw material and nitrogen-containing substances as nitrogen source. Nitrogen doping under high temperature or hydrothermal conditions. The patent publication No. CN104465113 discloses a method for preparing nitrogen-doped graphene by hydrothermal method. Heat reaction for 2 hours to obtain nitrogen-doped graphene. Because graphene oxide is not easy to obtain and the cost is high, this method is limited

[0004] There are many problems in the above method, such as low nitrogen doping amount, low graphene reduction rate, and many defects in doped graphene.

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