Reconstructing a Nanoporous Metal in Three Dimensions: An Electron Tomography Study of Dealloyed Gold Leaf

Abstract

Nanoporous gold, prepared by electrochemical dissolution of Ag from commercial white gold leaf, was investigated by HAADF-STEM tomography. The three-dimensional reconstruction shows a fully connected network structure composed of single-crystalline gold ligaments and pores. We have applied stereological analyses to characterize the pore volume fraction, the specific surface area, and the mean surface curvature. The structure exhibits broad distributions in pore as well as ligament size, a convex surface and a significant microstructural anisotropy. The ligaments contain encased voids which are believed to form during the dissolution process.