Nucleation and growth of metal on nanoelectrodes

Three-dimensional nucleation and growth on active surface sites are fundamentally important initial stages of the electrodeposition of metals. Electrochemical studies of these processes are greatly complicated by the formation of multiple crystals interacting with each other. We investigated Ag electrodeposition on the surface of well-characterized, nanometer-sized Pt electrodes and measured the nucleation/growth kinetics of individual Ag crystals by a combination of nanoelectrochemistry and atomic force microscopy (AFM). Basic parameters, including the number of surface active sites, the kinetic time lag and the number of growing nuclei, were directly accessed from current transients and in situ AFM imaging. The existence of a single nucleation site on the surface of a 50 nm electrode persisting through several deposition/stripping cycles has been demonstrated.