Kinetics of anisotropic growth of silver nanocrystals via the galvanic replacement of silver on nickel nanoparticles in aqueous solution

The effect of silver nitrate concentration on the kinetics of galvanic replacement of silver on nickel nanoparticles (NiNPs) in aqueous solution was investigated. A kinetic model describing the process, which accounts for variations in Ag + concentration and the number of active nickel surface sites, is proposed, and the corresponding rate constant is determined. Transmission electron microscopy (TEM) revealed that silver predominantly crystallizes in the form of nanoplates exhibiting a single-crystalline structure. The obtained results indicate that the anisotropic growth of silver nanostructures can be achieved under surfactant-free conditions and is governed by the interplay between reaction kinetics and surface processes on NiNPs.