07 Apr Oxidative Exfoliation
For the oxidative exfoliation method, graphite is commonly oxidized under harsh conditions to obtain graphite oxide. This bulk material can be dispersed by sonication in polar solvents, e.g. water, to form graphene oxide.
The oxidation introduces a large amount of oxygen containing functional groups which allows the oxidative exfoliation to even obtain single layer graphene (SLG) and ensures the stability in dispersion without the need of further additives.
However, these functional groups interrupt the honeycomb structure of graphene, which is responsible for the extraordinary properties.
Therefore, this family of graphene materials can have lowered thermal or electrical conductivity. In order to resolve this problem, graphene oxide is most commonly reduced with agents, like hydrazine, or through electrochemical approaches to form so-called reduced graphene oxide (rGO).
However, this reduction process is never 100% complete and can even introduce holes into the carbon lattice. Even if rGO is stills lightly oxidized compared to pristine graphene it has been used for the development of many applications and has shown its convenience.