Graphene uniformly decorated with gold nanodots: in situ synthesis, enhanced dispersibility and applications

Graphene sheets decorated with metal nanoparticles are emerging novel graphene-based hybrids for tuning the intrinsic properties of both components for fundamental research and technological applications. Here we report a new wet-chemistry strategy to efficiently and uniformly decorate reduced graphene oxide (RGO) with unique gold nanodots (GNDs). Non-covalent self-assembly of a perylene thiol derivative (ETPTCDI) on the basal plane of GO forms graphene by reducing the dispersed GO and serves as an excellent two-dimensional template in solution for in situ nucleation and growth of gold nanodots via thiol-Au bonding. We characterized the resulting RGO-ETPTCDI-GND in detail and confirm that the Au nanodots with unique size (∼2 nm) decorate the RGO-ETPTCDI sheets uniformly due to the self-assembly of ETPTCDI molecules on the basal plane of graphene. We demonstrate that our RGO-ETPTCDI-GND sheets have astonishing dispersibility, reliability, and processibility. The uniform decoration of the ∼2 nm GNDs on the graphene surface makes it possible to use the nanodots as a contrast enhancement agent for easily revealing the fine structure of the graphene surface. The electrochemical activity of our RGO-ETPTCDI-GND modified glassy carbon electrode showed significant improvement, suggesting RGO-ETPTCDI-GND as an attractive robust and advanced hybrid electrode material with great promise for electrochemical sensors and energy conversion.