Metal free graphene based catalysts: A review

Graphene, a two dimensional, single-atom thick, periodic structure composed entirely of aromatic carbon atoms, and graphene oxide, a highly oxidized form of graphene, are relatively new materials with incredibly interesting chemical and mechanical properties. These materials have already demonstrated their potential importance in the future of nanotechnology, while their application as catalysts is beginning to emerge. Because of its high surface area and/or tunable electrical properties, graphene and graphene oxide have been widely explored as catalyst supports for metal nanoparticles. Recently, graphene oxide has been shown to be able to function as metal-free catalyst for a variety of chemical transformations that typically are catalyzed with precious metals or under very harsh conditions. Additionally, the variety of oxygenate functional groups on graphene oxide makes it an attractive platform to tether other catalytically active groups (e.g. amines). The development of new heterogeneous metal-free catalysts using graphene oxide could lead to "greener" methods for a variety of chemical transformations of interest to the chemicals and other industries. This review explores some of the recent advances that uncover the potential of graphene and graphene oxide for use in metal-free heterogeneous catalysis.