Method for electrochemically preparing ultra-thin graphene nanosheets

Abstract

The invention relates to a method for electrochemically preparing ultra-thin graphene nanosheets and belongs to the technical field of graphene preparation. The method comprises the following steps: by taking an electrode formed by layered graphite as an anode, a metal or a graphite electrode as a cathode, and a liquid-phase system with carboxylic acid as electrolyte and an intercalation source, applying certain current between the anode and the cathode, and carrying out an electrochemical reaction so as to obtain a carboxylic acid intercalation graphite compound; performing thermal peeling and mechanical peeling, and repeating the operation for multiple times, so as to obtain the ultra-thin graphene nanosheets of which the average thickness is not greater than 2nm or the layer number is not greater than 5. By adopting the preparation process provided by the invention, high-temperature peeling is not needed, no waste gas can be generated, no strong acid is used, the environment damagecan be reduced to the maximum extent, in addition, GICs (intercalation graphite compounds) which can be relatively and uniformly peeled can be prepared, the method is applicable to production of nano-grade graphene sheets which are relatively small and uniform in size, and in addition, the method provided by the invention is simple, low in energy consumption, low in equipment requirement, short intime consumption and applicable to industrial production.

Description

technical field [0001] The invention belongs to the technical field of graphene preparation, and more specifically, the invention relates to a method for electrochemically preparing ultrathin graphene nanosheets. Background technique [0002] Carbon is known to have four unique crystal structures, including diamond, graphite, fullerene and carbon nanotubes (CNTs). Carbon nanotubes refer to tubular structures grown with single or multiple walls, which can be obtained by rolling up a graphene sheet or multiple graphene sheets to form a concentric hollow structure, with a diameter of several nanometers to hundreds of nanometers, which can be Used as a conductor or semiconductor. Carbon nanotubes are considered to have great application potential in field emission devices, hydrogen fuel storage, fuel cell electrodes, and composite reinforcement materials. However, the current carbon nanotube preparation process not only has the problem of low yield and low production efficienc...

AI Technical Summary

Problems solved by technology

There are two main problems in these processes: ① strong acid waste liquid; ② waste gas generated during the high temperature stripping process, these all involve environmental pollution problems, and have a great impact on the environment, and the secondary treatment of waste waste liquid requires expensive equipment and process complex

In addition, the exfoliation temperature of intercalated graphite is generally between 800-1100°C. At this high temperature, graphene may be severely oxidized, which greatly reduces the electrical and thermal conductivity of graphene.

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