Silver electrodeposition from AgNo3 solutions containing organic additives: Electrodeposition from binary water-methanol solvent systems in the presence of tartaric acid

Abstract

The electrodeposition of silver at 25°C from AgNO3/tartaric acid solutions in binary water-methanol solvent systems was investigated. This study shows that it is possible to obtain compact and coherent silver deposits from AgNO3 solutions only in the presence of tartaric acid (H 2A). The relevant chemical entity controlling growth inhibition is a neutral associate Ag(HA) formed in the solution between Ag+ and tartaric monoanions HA-. Most of the structural features of Ag deposits such as grain size, surface roughness and degree of the preferred orientation 〈1 1 0〉, depend on the concentration of this associate. These properties of the deposits can easily be controlled by: (a) modifying the concentration of AgNO3 or H2A, (b) adjusting the pH of the bulk solution by addition of HNO3 and (c) modifying the composition of the mixed solvent system.