Control of Ag deposition for improvement of specular reflection in Ag deposition-based electrochemical mirror through modulation of electrolysis condition

Abstract

The reflection behavior of an Ag deposition-based reversible electrochemical mirror is determined by the morphology of the electrodeposited Ag. This study demonstrates the control of the morphology of Ag deposits through the modulation of the electrolysis conditions, specifically the applied potential and Ag+ ions concentration, without increasing the amount of Ag deposits. By applying a potential with a sufficiently large deposition overpotential for continuous deposition on the electrode surface, the deposited Ag formed a flat surface, resulting in high reflectivity. Considering the concentration dependence of Ag+ ions, the diffusion of Ag+ ions to the electrode significantly affected the resulting morphology of the deposits. At higher Ag+ concentrations, the time for the transition to a diffusion-limited process increased because Ag+ ions were close to the working electrode. Therefore, a flat Ag layer was obtained due to the promotion of three-dimensional deposition, including the in-plane growth.