Surface Structures and the Crystal Habit of Growing Particles

A truncated single-crystal surface varies to a more stable two-dimensional array of atoms by raising the temperature. On the other hand, metal particles may grow via a two-dimensional precursor array of atoms. The (1 × 1) Au(111), Au(110), and Au(100) surfaces undergo reconstruction in electrolyte solutions at a certain negative electrode potential (vs. SCE). The icosahedral or decahedral Au particles are preferentially grown on an electrode held at the same negative electrode potential making reconstruction of Au crystal surfaces. The result suggests that metal particles may grow via precursor states of metal array which are similar to two-dimensional array of the reconstructed surfaces. Multi-twin Pt particles are also formed at highly negative electrode potential.