Stabilizing high-energy crystal structure in silver nanowires with underpotential electrochemistry

Abstract

We demonstrate that commonly face-centered cubic (fcc) metallic nanowires can be stabilized in hexagonal structures even when their surface energy contribution is relatively small. With a modified electrochemical growth process, we have grown purely single-crystalline 4H silver nanowires (AgNWs) of diameters as large as 100 nm within nanoporous anodic alumina and polycarbonate templates. The growth process is not limited by the/A_g Nernst equilibrium potential and time-resolved imaging with high-resolution Transmission Electron Microscopy (TEM) indicates a kinematically new mechanism of nanowire growth. Most importantly, our experiments aim to separate the effects of confinement and growth conditions on the crystal structure of nanoscale systems.