Method for reducing exfoliated graphene oxide by lithium-assisted microwave thermal expansion method

Abstract

The invention relates to the field of nano carbon material preparation, in particular to a method for reducing exfoliated graphene oxide by a lithium-assisted microwave thermal expansion method. The preparation of lithium-assisted microwave reduction graphene is completed under the conditions of ultrasonic treatment, blast drying and microwave heating, in the microwave heating process, oxygen-containing functional groups on graphene oxide fall off to be released as gas, pressure is generated, thermal expansion occurs among graphene layers to peel off, and high-quality graphene is prepared at low temperature and normal pressure. In the microwave heating process, the decomposition rate of the oxygen-containing functional groups in the graphene oxide is higher than the diffusion rate of the generated gas, and the Van der Waals' force capable of overcoming the combination of graphene sheet layers is generated, so that reduction and exfoliation are achieved. The existence of lithium breaks an original electronic structure and is more beneficial to exfoliation of the graphene sheet layers. The preparation method is simple in process, high in preparation speed and low in cost and can be used for large-scale production, and the product is black floccules.

Description

technical field [0001] The invention relates to the field of nano-carbon material preparation, in particular to a method for reducing and exfoliating graphene oxide by a lithium-assisted microwave thermal expansion method. Background technique [0002] Graphene is composed of carbon atoms arranged in a hexagonal honeycomb lattice. It has excellent electrical, optical, thermal and mechanical properties, and is an ideal carbon nanomaterial. Graphene's application research is emerging, and it has broad application prospects in many aspects including low-cost seawater desalination, high-strength composite load-bearing materials, high-frequency transistors, solar cells, sensors, catalysis, lithium-ion batteries, and supercapacitors. Therefore, it is imperative to prepare high-quality graphene. Graphene can be prepared by ultrasonic exfoliation or ball milling of expanded graphite, but the degree of thermal expansion and thus the thickness of the sheet is affected by the type of ...

AI Technical Summary

Problems solved by technology

Graphene can be prepared by ultrasonic exfoliation or ball milling of expanded graphite, but the degree of thermal expansion and thus the thickness of the sheet is affected by the type of graphite and the insertion process of the expansion agent. The thickness of the sheet is generally thick, and it is difficult to obtain a single layer or less layers of graphene

[0003]The conventional thermal expansion method needs to be carried out under high temperature and high pressure, requires relatively harsh preparation conditions, and has high energy consumption and few products. Therefore, it is necessary to prepare a large amount of high-quality High-quality graphene, it is imperative to create a new preparation method

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