In-situ electrochemical atomic force microscopy studies of nucleation of single nucleus on microelectrodes

Abstract

The electrochemical nucleation and growth of silver single nucleus on glassy carbon microelectrode have been monitored in-situ with electrochemical atomic force microscopy (ECAFM) at different stages. The AFM results show that the silver single nucleus forms at the edge of the glassy carbon and grows to form a crystallite with (100) facet preferentially dominated. It is confirmed that the nucleation process strongly relies on the condition of glassy carbon substrate. Multiple nuclei are formed on the substrate with nucleation history but single nucleus can be achieved on the same substrate after the application of a special ''purging'' method. The work is the first example for the real time observation of nucleation and growth of a single nucleus on a microelectrode and for the application of ECAFM to the studies of microelectrode systems. Comparison of the work with previous ex-situ measurements are given. The work also demonstrates a possible way to obtain a single crystal microelectrode which could be valuable for various purposes.