Large graphene manufacturers:
Eastern China: Shanghai Carbon Source Huigu New Material Technology Co. Kaina Graphene Technology Co., Ltd, Changzhou 2D Carbon Technology Co., Ltd, Ningbo Mexi Technology Co.
North China: Tianjin Plain Nano Technology Co.
Central China ：Changsha Ross Technology Co.
Northwest China ：Xi'an Hua Wu Graphene Co.
Southwest China? : Deyang Alkene Carbon Technology Co. and Chengdu Organic Chemistry Co. of the Chinese Academy of Sciences.
Three methods of producing graphene: Generally speaking, there are 1. vapor deposition 2. redox 3. intercalation.
1. Meteorological deposition method is mainly carbon-containing gases (methane, iso), at a certain temperature and pressure conditions, the carbon atoms in the growth of the base attachment, the formation of a single layer of carbon structure and the gradual growth of the material. Advantages: the resulting graphene has a good structure and the size is not limited by raw materials. Disadvantages: the preparation process is complicated and the production efficiency is low.
2. The redox method uses an oxidizing agent to oxidize graphite layer by layer, and uses ultrasound and other means to peel off the oxidized layer. After that, the use of reducing agent will be oxidized graphite layer reduction, that is to get graphene. Advantages: low cost, high production efficiency. Disadvantages: the size of graphene is determined by the raw material, and the oxidizing agent and reducing agent used have the possibility of polluting the environment.
3. Interpolation method is to fill the interlayer material into the graphite layer gap, than to overcome the interlayer van der Waals force, making the layers dispersed, so as to obtain graphene. The method is still in the research and development stage.