Gold Microplates with Well-Defined Shapes

The synthesis and growth mechanism of well-defined nanostructures are still challenging. In this study, gold microplates with starlike, shieldlike, and other polygonal shapes are successfully achieved in high yields on the basis of the polyol process. Structural studies demonstrate that these newly shaped Au plates are single-crystalline, several micrometers in lateral size, and tens of nanometers in thickness. It is believed that the introduction of temperature variation in the early stage of crystal growth is important for these products. The newly discovered Au microplates result from the growth of the fill plane along the < 211 > and other high-index directions, in addition to the {111}-close-packed < 110 > directions. Simulations on the multiple-twin-induced crystal growth and surface energy are also carried out to explain the experimental observations. This work is valuable for anisotropic growth of newly shaped noble-metal nanostructures.