Nanoelectrochemistry of Metal Dissolution and Deposition Reactions

Abstract

Electrochemical metal dissolution and depositions reactions are reversible processes involving phase transition, which are fundamentally important in battery and corrosion. The electrode kinetics of these reactions are highly sensitive to the surface structures. In this talk, I will present the study on the initiation of metal dissolution reactions on Ag and Ni, representing model systems for oxide-free and oxide-covered metals, respectively. The local dissolution kinetics is voltammetrically mapped via scanning electrochemical cell microscopy (SECCM). Co-localized characterization of crystal orientation reveals slower dissolution on {111} close-packed planes. Direct measurement of local dissolution kinetics on grain boundaries shows a faster dissolution rate on some but not all grain boundaries. We demonstrate that correlative electrochemical and structural imaging are powerful tools for studying heterogeneity at complex electrochemical interfaces, which can also be used to study metal deposition reactions at the nanoscale.