Graphene, as an emerging two-dimensional material, is known for its excellentThe mechanical, electrical and thermal properties have attracted widespread attention. Since its discovery, scientists have worked to develop efficient and sustainable preparation methods to meet the growing needs of industry. In this paper, we will discuss the main graphene preparation technologies, including micromechanical stripping, solvent stripping, redox and chemical vapor deposition, and analyze the advantages and disadvantages of each method and its application potential, so as to provide a reference for in-depth understanding of the preparation and application of graphene.
There are four main preparation methods: micromechanical stripping, solvent stripping, redox and chemical vapor deposition (CVD), each of which has its own special advantages and disadvantages and application scenarios.
1. Micromechanical peeling method
Micromechanical exfoliation is the earliest technology used to prepare graphene, which uses mechanical external force to peel off graphite layers layer by layer. This method enables the production of high-quality single-layer graphene, but it is difficult to achieve large-scale production due to its low yield and non-adjustable size. To this end, researchers such as Dan et al. proposed the ball milling method, which strips graphite and functional graphene on an industrial scale through environmentally friendly mechanochemical treatment, although the internal structure of graphene is damaged to a certain extent.
2. Solvent stripping method
The solvent stripping method achieves stripping by dispersing graphite in a solvent and using ultrasonic waves to destroy the van der Waals force between the layers, causing the solvent molecules to be inserted between the graphite layers. This method can better retain the crystal structure of graphene and prepare high-quality graphene. However, due to its high cost and insufficient yield, it is difficult to meet the needs of industrial production.
3. Redox method
Redox is a well-established technology for large-scale preparation of graphene. In this method, natural graphite is oxidized and oxygen-containing functional groups are introduced to generate graphite oxide. Subsequently, it is exfoliated into graphene oxide (GO) after ultrasonic dispersion or rapid expansion, and finally the oxygen-containing functional groups are removed through the reduction process to obtain graphene. Although the method is simple to operate and has low equipment requirements, it is easy to produce defects during the reaction process, which affects the mechanical and conductivity properties of graphene. In addition, the problem of waste liquid treatment by redox method also needs to be paid attention to.
4. Chemical vapor deposition (CVD)
Chemical vapor deposition is widely used in the preparation of high-quality single-layer graphene. In this method, carbon atoms are gradually released by decomposing hydrocarbons at high temperatures, so that they are deposited to form graphene films. The CVD method can not only prepare graphene films with a large area, but also has high quality and fewer defects, which is very suitable for electrical performance research and a reliable choice for industrialization.
Fields of application
Due to its excellent properties, graphene has a wide range of applications, including anti-corrosion coatings, lithium batteries, conductive inks and heat dissipation materials.
The conductivity of graphene can form a stable conductive network in the coating, reduce the amount of zinc powder, and improve the anti-corrosion performance of the coating.As a conductive additive, graphene has significantly improved the conductivity and cycle life of lithium batteries, and has become an important part of high-performance lithium-ion batteries.Graphene's excellent compatibility and low cost make it excellent in the application of conductive inks, and it is expected to be widely used in the field of printed electronics in the future.The application of graphene in heat sinks has attracted attention because of its good thermal conductivity and foldability, especially in the field of smart devices.
The preparation methods of graphene have their own characteristics and are suitable for different application scenarios. Although there are still some challenges to current technologies, such as yield, cost, and environmental impact, it is expected that more efficient and environmentally friendly preparation solutions will emerge in the future as research continues to advance. The wide application of graphene will promote technological innovation in many fields and show considerable development prospects. Through further research and industrialization, the potential of graphene will be more fully exploited for the benefit of various industries.
