An in situ oxidation route to fabricate graphene nanoplate–metal oxide composites

We report our studies on an improved soft chemical route to directly fabricate graphene nanoplate–metal oxide (Ag2O, Co3O4, Cu2O and ZnO) composites from the in situ oxidation of graphene nanoplates. By virtue of H+ from hydrolysis of the metal nitrate aqueous solution and NO3−, only a small amount of functional groups were introduced, acting as anchor sites and consequently forming the graphene nanoplate–metal oxide composites. The main advantages of this approach are that it does not require cumbersome oxidation of graphite in advance and no need to reduce the composites due to the lower oxidation degree. The microstructures of as-obtained metal oxides on graphene nanoplates can be dramatically controlled by changing the reaction parameters, opening up the possibility for processing the optical and electrochemical properties of the graphene-based nanocomposites.