Sonoelectrochemical intercalation and exfoliation for the preparation of defective graphene sheets and their application as nonenzymatic H2O2 sensors and oxygen reduction catalysts

Abstract

A sonoelectrochemical synthetic method is reported for rapidly preparing and dispersing reduced graphene nanosheets (RGN_SECM) stabilized in an aqueous electrolyte. The X-ray photoelectron and Raman results demonstrate that the defects on RGN_SECM are predominantly physical and not similar to the chemical defects on reduced graphene nanosheets (RGN_CM) synthesized via chemical reduction of graphene oxide nanosheets based on the Hummer's method. The in-plane crystallite size (L_a) of RGN_SECM is 26.8 nm, larger than the 18.2 nm of RGN_CM. The RGNs prepared using the sonoelectrochemical method (RGN_SECM) were successfully applied as nonenzymatic H₂O₂ sensors and alkaline oxygen reduction reaction (ORR) catalysts. Using electrochemical analysis, a fair comparison of the performances of RGN_SECM and RGN_CM as H₂O₂ sensors and ORR catalysts has been performed.