A new gold nanostructure, shield-like Au nanoparticles with a single twin plane and high-index {hhl} facets, was discovered in a simple seed-mediated synthesis. The development of this new shape was believed to be due to the preferential adsorption of cetyltrimethylammonium cations on high-index facets and the coalescence of the nanoparticles by the charge screening effect of NaCl. These shield-like Au nanoparticles display some properties that were distinctively different from other types of Au nanoparticles.

Synthesis of Shield-Like Singly Twinned High-Index Au Nanoparticles. Y.Yu, Q.Zhang, J.Xie, X.Lu, J.Y.Lee: Nanoscale, 2011, 3[4], 1497-500