A subcritical reaction preparation method of three atomic layer high-quality graphene materials

Abstract

The invention provides a subcritical preparation method of three-atomic-layer high-quality graphene. The subcritical preparation method comprises the following steps: iodine bromide is used as an intercalation agent to prepare a three-order graphene intercalation compound, then the three-order graphene intercalation compound is placed in a subcritical water environment, an intercalation agent (iodine bromide) is dissolved in water and generates violent reaction with water in a graphite layer, the violent reaction and the high-pressure permeation action of the subcritical water environment acton a graphite sheet layer, and by peeling, the graphene material with the three-atomic-layer thickness is obtained. The subcritical preparation method provided by the invention has the beneficial effects that the adopted subcritical reaction temperature is 100-240 DEG C, so that the subcritical preparation method is suitable for industrial or laboratory operation; due to rapid reaction, the subcritical preparation method is suitable for preparing large-laminar graphene materials with three-atomic-layer thickness and can be used for the fields of transparent conducting films, energy storage devices and superconductors and the like.

Description

technical field [0001] The invention relates to the field of preparation of high-quality graphene materials, in particular to a method for rapidly and controllably preparing three-atom-layer high-quality graphene materials by using subcritical reactions. Background technique [0002] Graphene is a completely sp 2 The quasi-two-dimensional crystal material composed of hybrid carbon atoms with a thickness of only one atomic layer or several single atomic layers is almost completely transparent, has high thermal conductivity, high electron mobility at room temperature, and is the material with the smallest resistivity in the world. It is also the thinnest yet hardest nanomaterial in the world. Graphene can be used to develop a new generation of thinner and faster conductive electronic components, transparent touch screens, high-performance nanoelectronic devices, optoelectronic devices, and can also be used in gas sensors, composite materials, field emission materials and ener...

AI Technical Summary

Problems solved by technology

The first method used is the micro-mechanical separation method. The single-layer graphite sheet obtained by this method is relatively complete, but the size of the single-layer graphite cannot be controlled. This method is manually operated, and the thickness is not uniform.

The oxidation process of graphite oxide reduction method usually seriously damages the structure of graphene sheets. Although after reduction treatment, the performance indicators of the obtained graphene materials still have a large gap with high-quality graphene.

In addition, the oxidation process of graphite usually requires a large amount of strong acidic oxidants such as concentrated sulfuric acid, concentrated nitric acid, dichromic acid, potassium permanganate, sodium nitrate, etc.; while the reduction process requires high temperature treatment or the use of hydrazine, dimethylhydrazine, etc. Toxic chemicals not only consume a lot of energy, are inefficient, costly and pollute the environment

Graphene prepared by chemical vapor deposition does not exhibit the quantum Hall effect. How to select a suitable substrate is also a difficult problem. At the same time, it has the disadvantages of high cost and complicated process.

Solvent exfoliation method can prepare high-quality graphene, but liquid-phase ultrasonic exfoliation often requires long-term ultrasound, and some even reach hundreds of hours, which inevitably destroys the integrity of graphene and affects its performance.

In addition, there are also many reports on the preparation of graphene by supercritical methods. This method requires relatively expensive supercritical equipment, requires high pressure and temperature, and has low production efficiency.

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