Electrical double layer formation on glassy carbon in aqueous solution

Abstract

Herein we report on the use of step potential electrochemical spectroscopy (SPECS) to characterize the dynamics of charge storage on a planar non-porous glassy carbon electrode in an aqueous electrolyte. Comparison between the spatial requirements of solvated electrolyte ions and the amount of charge added to the electrode surface implies that electrolyte charge storage is diffuse in nature, extending a substantial distance into the electrolyte, even for a concentrated electrolyte. This is contrary to the expected parallel planes of charge expected for double layer formation at the interface. The implications of this on the use of porous materials is also discussed.