▎ 摘　　要

Even though graphene has been intensively applied in electrochemical devices, the effects of oxidation and how the presence of graphene structural defects interferes with the monolayer graphene electrode-aqueous electrolyte interface remains unclear. Here, we investigate the role of structural defects in the quantum capacitance at the interface between a graphene monolayer and the aqueous electrolyte solution, where the graphene was gradually oxidized by a temporal-controlled electrochemical procedure. We show that the quantum capacitance of graphene can be modulated by tuning the electronic properties, which resulted in a three-fold increase from a value of 3.83 mu F cm(-2) for the pristine graphene up to 11.11 mu F cm(-2) for the structurally modified monolayers. A strong correlation is observed between the carrier concentration, density of defects, and quantum capacitance. We suggest that the control of such properties can modulate the performance of graphene-based electrochemical devices according to application.