Preparation of Ag Stellar Dendrites: Modeling the Growth of Stellar Snowflakes

Abstract

The synthesis of Ag stellar dendrites was achieved using a solution-phase method by modeling the growth of stellar snowflakes. In the synthesis, 2,3-bis(2-pyridyl)pyrazine (dpp) acted as the growth-directing agent, forming hexagonal structures that served as the nuclei for the growth of stellar dendrites. Coupled with the careful control of experimental parameters to achieve a balance between reaction and diffusion rates, uniform and directional growth ensued, yielding symmetrical stellar dendrites represented by {111} facets. The influences of experimental conditions were investigated by analyzing the products formed under varied reaction and diffusion rates. The results were organized into an empirical chart that can serve as a visual reference to determine the experimental modifications required to prepare stellar dendrites. Time-dependence studies were carried out to elucidate the mechanism of growth into the unique dendritic patterns. SEM and HRTEM imaging of the intermediate structures revealed that...