Microwave Exfoliation of Graphite Oxides in H₂S Plasma for the Synthesis of Sulfur-Doped Graphenes as Oxygen Reduction Catalysts

Tuning the electronic and chemical properties of graphene can be carried out through heteroatomic doping, enabling its use as an electrocatalyst. Sulfur-doped graphene has been suggested to be a viable alternative to traditional Pt-based catalysts for oxygen reduction under alkaline conditions. Herein we present a fast and efficient route to synthesize S-doped graphenes through the microwave-assisted exfoliation and reduction of three different graphite oxides in the presence of hydrogen sulfide. The materials obtained were characterized using scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, combustion elemental analysis, and voltammetry. These S-doped graphenes were found to have good electrochemical performance and were active in the catalysis of the oxygen reduction reaction.