Ag nanostructures with various shapes created through degradation of rods

Abstract

We developed a facile method (a polyol synthesis) to prepare uniform silver nanostructures with various morphologies using ethylene glycol (EG) reduction of silver nitrate at 120 °C in the presence of poly(vinyl pyrrolidone) (PVP) and NaCl. Ag rods were fabricated by simply aging the freshly prepared AgNO3 solution with PVP, EG, and NaCl under ambient atmosphere without changing other parameters. The formation and degradation of the rods were systematically investigated. The result indicates that twinned-crystal seeds play an important role for the growth of anisotropic Ag rods. The NaCl concentration in solutions affected the formation of the rod. The rod was degraded subsequently via an etching process of O2/Cl¯ (NaCl), resulting in the formation of Ag nanostructures with various shapes. Twinned Ag seeds in solutions were etched by increasing the concentration of NaCl, yielding uniform Ag cubes. Regular Ag cubes were fabricated under optimal preparation conditions. Ag cubes with various sizes (150–600 nm) were created by adjusting PVP concentrations in solutions.