Self-organization processes and synthesis of nanostructured silver microparticles in AgNO3 solutions with variable pH values

Resumo

The morphology of micrometer-sized silver particles obtained by liquid-phase chemical reduction of silver nitrate with ascorbic acid depends appreciably on the solution pH. The synthesis carried out at 100°C for 20 min at pH < 4 or pH > 9 yields anisotropic faceted nanocrystalline particles, while the synthesis at pH = 5–8 results in self-assembly to give microspheres representing close-packed aggregates of a huge number of silver nanoparticles with a cauliflower structure.