Visualizing the Effect of Partial Oxide Formation on Single Silver Nanoparticle Electrodissolution

Abstract

The impact of heterogeneous surface oxide formation on the electrochemical performance of single silver nanoparticles is explored using in situ superlocalization optical microscopy. Silver nanoparticles are well-known to form a natural oxide layer on their surface, but the effect of this oxide layer on electrochemical reactions is not well understood. Here we track the temporal and spatial dependence of electrodissolution of single silver nanoparticles in order to study the role of surface oxide layers on electrochemical reactions. Heterogeneity in electrodissolution kinetics is observed by following the time-dependent loss in scattering intensity from individual silver nanoparticles using dark-field scattering. Both fast and slow dissolution kinetics are observed, with the dominant pathway changing as a function of applied potential. To understand this, superlocalization imaging is employed to follow the spatial variance of the electrodissolution process and reveals that the silver nanoparticles undergo ...