Consequences of edge and substrate modifications on graphene electrochemistry

The electrochemistry of graphene is dictated by its structural inhomogeneities, including defects, edges, and substrate interactions, along with its unique electronic properties. In this current opinion, we analyze how graphene's structural features influence its heterogeneous electron transfer (HET) kinetics. Graphene's low density of states (DOS) introduces quantum capacitance effects that dominate interfacial charge transfer near the charge neutrality point. Defects, such as vacancies and oxidized regions, create localized states that enhance HET rates, while excessive defects reduce conductivity. Graphene edges, show superior HET performance compared to the basal plane. Encapsulation techniques, such as hexagonal boron nitride, enable precise isolation of graphene edges, minimizing capacitive interference. Substrate engineering, including metallic hybridization and twisted bilayer graphene, further modulates graphene's electronic properties. These insights feature graphene's potential in biosensing, energy storage, and catalysis, while highlighting the need for precise defect control and substrate optimization to advance graphene-based electrochemical devices.