Directly bonded hybrid of graphene nanoplatelets and fullerene: facile solid-state mechanochemical synthesis and application as carbon-based electrocatalyst for oxygen reduction reaction

Abstract

Using a facile solid-state mechanochemical method by ball milling, we successfully synthesized the first directly bonded graphene–C₆₀ hybrid, for which LiOH is found to play a crucial role as the catalyst. The hybrid structure of graphene–C₆₀ is confirmed by FTIR, Raman, XRD and XPS characterizations, and its conformation is proposed, featuring the direct bonding of graphene nanoplatelets and C₆₀via two C–C single bonds. SEM measurement suggests that severe edge distortions occur for graphene–C₆₀ hybrid, and HR-TEM study indicate the covalent attaching of C₆₀ molecules onto the edge of graphene nanoplatelets. The graphene–C₆₀ hybrid is applied as a carbon-based electrocatalyst toward oxygen reduction reaction (ORR), showing improved ORR electrocatalytic activity than the pristine graphite.