Decoration of electro-reduced graphene oxide with uniform gold nanoparticles based on in situ diazonium chemistry and their application in methanol oxidation

Decorating graphene with high destiny and uniform size of noble metal nanoparticles is very important for a number of applications including sensing and electrocatalysis. Herein, a novel approach based on in situ diazonium chemistry was reported to design gold nanoparticles/graphene hybrid materials (Au-NPs/G). Graphene oxide was firstly electro-reduced on the glassy carbon electrode, and then this modified electrode was grafted by aminophenyl diazonium cations, generated in situ from p-phenylenediamine. Subsequently, gold nanoparticles (Au-NPs) were deposited on the p-phenylenediamine grafted electrode by a potentiostatic method. X-ray photoelectron spectroscopy, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the Au-NPs/G. The results demonstrated that the Au-NPs with high destiny and uniform size were dispersed on the electro-reduced graphene oxide. In addition, the obtained Au-NPs/G was utilized in electrocatalysis toward the oxidation of methanol showing excellent catalytic activity.