Diffuse Double Layer at Nanoelectrodes

Abstract

Numerical solution of the equilibrium Poisson−Boltzmann equation for hemispherical electrodes of vanishing size reveals that the effects of curvature on the diffuse double layer become significant for electrodes with radii less than 50 nm. These effects include dramatically enhanced capacitance and hence more a rapid potential drop from the outer Helmholtz plane as far as the characteristic tunnelling length for electron transfer. An enhanced driving force is therefore expected for nanoelectrodes as compared to electrodes larger than 50−100 nm, especially at low concentrations of supporting electrolyte.