Method for preparing high-quality graphene through electrochemical high-efficiency exfoliation

Abstract

The invention relates to a preparation method for graphene, especially to a method for preparing high-quality graphene through electrochemical high-efficiency exfoliation. The method mainly overcomes the technical problems that the honeycomb lattice structure of graphene is severely destroyed in the process of oxidation, an obtained membrane resistance is 1 K to 70 K omega / square (wherein light transmittance is less than 80%), the resistance is too high and much higher than requirements of ITO, etc. The method comprises the following steps: with graphite as a positive electrode and a platinum filament as a negative electrode, repeatedly applying high offset voltage and negative offset voltage on the graphite electrode, which enables graphite to be rapidly disassociated and decomposed into double-layer graphene floating on the surface of an electrolyte; collecting graphene and then filtering and drying graphene; dispersing obtained powder of a graphene film in a DMF solution; and carrying out water-bath ultrasonic treatment and centrifugation so as to obtain desired 1.5-nm-grade graphene flakes.

Description

technical field [0001] The invention relates to a method for preparing graphene, in particular to a method for preparing high-quality graphene by electrochemical efficient exfoliation. Background technique [0002] Graphene is an atomic graphite due to its two-dimensional structure and unique physical properties, such as high intrinsic electron mobility (~20000cm 2 / / v 3s) 2 , excellent mechanical strength, flexible elasticity, and good electrical conductivity, have attracted extensive attention. Existing graphene preparation methods include mechanical exfoliation, epitaxial growth, vapor deposition, and redox methods. However, graphene prepared by mechanical exfoliation and epitaxial growth has high quality, but it is not suitable for large-scale production. Recent research using chemical vapor deposition on catalytic metal substrates has made great progress to show that large-area graphene can increase capacity and expand its application in highly transparent and flexib...

AI Technical Summary

Problems solved by technology

However, graphene prepared by mechanical exfoliation and epitaxial growth has high quality, but it is not suitable for large-scale production

Recent research on chemical vapor deposition using catalytic metal substrates has made great progress to show that large-area graphene can increase the capacity and expand its application in highly transparent and flexible conductive films, but the preparation is expensive and must Efforts to reduce production costs

The preparation of graphene by chemical or thermal reduction oxidation chemical exfoliation method has attracted people's attention due to the potential low cost and the advantages of liquid phase processing and manufacturing. However, the honeycomb lattice structure of graphene is severely damaged during the oxidation process. The obtained film resistance is from 1K to 70KΩ / □ (<80% light transmittance), the resistance value is too high, much higher than the requirements of ITO

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