Synthesis of a nanocomposite composed of reduced graphene oxide and gold nanoparticles.

We report a seeded-growth process that results in the adhesion of size-controlled gold (Au) nanoparticles (NPs) to the surface of reduced graphene oxide (rGO), leading to the formation of rGO-Au nanocomposites. The synthesis approach involves the utilization of Au molecular precursors (i.e., the seeds) bonded to oxygen functionalities which intrinsically exist on GO. Upon reduction of the Au precursors, surface deposition of Au NPs is ensured. It is found that the size of Au NPs is controlled via the variation of precursor concentration in the growth solution. The redox chemistry between GO and Au precursors causes the reduction of GO to rGO and the generation of Au NPs on the surface of rGO. Microscopic and spectroscopic measurements have been performed to provide evidence for the suggested redox chemistry.