Nanoscale control of plasmon-active metal nanodimer structures via electrochemical metal dissolution reaction

Herein, we report the control of the optical properties of metal nanodimer structures using electrochemical metal dissolution reactions. The reaction rate could be precisely tuned by changing the electrochemical potential and, as a consequence, fine tuning of the size and gap distance of metal nanodimers was achieved as the functions of applied potential and polarization time. The observed linear correlation between the scattering intensity and charge resulting from nanostructure dissolutions suggested that the surface dissolution rate was 0.30 nm min^-1, corresponding to the surface dissolution of a single atomic layer per min. The present method can control the change in the volume of the structures, leading to the change in the gap distance of nanodimers at an atomic-scale level.