Investigation of the surface plasmon polariton and electrochemical properties of covalent and non-covalent functionalized reduced graphene oxide

The surface electronic properties of graphene oxide (GO) were modified through reduction and functionalization. Non-covalent functionalization was found to be superior compared to covalent functionalization due to the formation of few-layer graphene with a low defect content and average crystalline length. Because of the restoration of sp(2) hybridization, non-covalently functionalized reduced graphene oxide (rGO) showed a better plasmonic response compared to GO, rGO and covalently functionalized rGO. Due to the available pi electrons from the sp(2) network of graphene as well as surface functionality, non-covalent functionalized rGO exhibited elevated donor density. Furthermore, due to the synergistic effect of surface electronic properties as well as adsorption and recombination at the barrier, superior charge transfer was achieved at the electrode-electrolyte interface for non-covalent functionalized rGO.