Method for rapidly preparing graphene in large quantities by utilizing graphite oxides

Abstract

The invention aims at providing a preparation method for rapidly obtaining graphene in large quantities. On the basis of obtaining graphite oxides, the molecular thermodynamic movement of groups such as hydroxyl groups (-OH), carboxylic groups (-COOH) and the like which are generated on the surfaces of graphite oxide layers through oxidization can be induced and stimulated through microwave treatment so as to produce a momentary unsteady state, so that Van der Waals binding force between graphite layers is damaged, and graphene can be rapidly obtained in large quantities. The graphite oxides are obtained through the oxidization of metal salt such as potassium permanganate, potassium dichromate and the like as well as strong protonic acid such as concentrated sulphuric acid, concentrated nitric acid and the like, and then microwave irradiation is carried out under the conditions that the power ranges from 2 to 10 kW, the vacuum pressure ranges from 0.01 to 0.06 MPa and so on, so that microwave cleavage of the graphite oxides can be accomplished within 2 to 10 seconds, and graphene with less than ten layers can be obtained rapidly in large quantities. The preparation method can also control the layer number or the thickness of graphene products by controlling the concentration and the oxidation time of oxidizing mediums as well as the power, the degree of vacuum and the like of the microwave irradiation.

Description

technical field [0001] The invention belongs to a preparation method for rapidly obtaining graphene in large quantities by using graphite oxide as a raw material. Specifically, it refers to the use of high-frequency and high-power microwave radiation to induce and excite the thermal movement of hydroxyl groups, carboxyl groups and other groups on the graphite oxide carbon layer, and instantly destroy the van der Waals bond between graphite layers, thereby achieving rapid mass production. Get graphene. Background technique [0002] Due to the excellent properties of graphene in mechanics, electricity, optics and many other aspects, people have been attracted to carry out a very wide range of theoretical research and application practice on graphene. However, as a unique two-dimensional crystal material, its preparation has always been the focus of attention. At present, the preparation and synthesis of graphene mainly revolves around two aspects: one is to obtain perfect tw...

AI Technical Summary

Problems solved by technology

However, using this method, the cycle is long. After the graphite oxide is obtained, it needs to be pickled and reduced with reducing agents such as hydrazine hydrate or sodium borohydride. In terms of products with low (especially single-layer graphene), there are still obvious deficiencies.

[0011] In addition, there are some novel graphene preparation methods such as cutting carbon nanotubes, but there are also complex processes and high equipment dependence, especially the rapid and macroscopic acquisition cannot be achieved.