Introduction of sulfur to graphene oxide by Friedel-Crafts reaction

Chemically modified graphene oxides have been intensively studied in the last decade. The introduction of heteroatoms is usually not well controlled and several different functionalities are formed. In this paper we introduced dithiocarboxylic acid on the graphene oxide by its reaction with carbon disulfide as a solvent and reagent and aluminum chloride as Friedel-Crafts catalyst. The presence of sulfur introduced into graphene was detected by elemental combustion analysis as well as by electron microprobe and X-ray photoelectron spectroscopy. The sulfur decorated graphene was applied for binding of gold nanoparticles to the graphene skeleton. Dithiocarboxylic acids are dominantly present on the edges and defect sites and have significant influence on electrocatalytic activity. These findings are highly important for applications of graphene derivatives in electrocatalysis. Dithiocarboxylic acid functionalities can be applied for coordination of transition metals as well as starting functional groups for further controlled modification of graphene and its derivatives.