Shaped gold and silver nanoparticles

Advance in the synthesis of shaped nanoparticles made of gold and silver is reviewed in this article. This review starts with a new angle by analyzing the relationship between the geometrical symmetry of a nanoparticle shape and its internal crystalline structures. According to the relationship, the nanoparticles with well-defined shapes are classified into three categories: nanoparticles with single crystallinity, nanoparticles with angular twins, and nanoparticles with parallel twins. Discussion and analysis on the classical methods for the synthesis of shaped nanoparticles in each category are also included and personal perspectives on the future research directions in the synthesis of shaped metal nanoparticles are briefly summarized. This review is expected to provide a guideline in designing the strategy for the synthesis of shaped nanoparticles and analyzing the corresponding growth mechanism.