Synthesis of silver nanostructures of varying morphologies through seed mediated growth approach

We report a method to synthesize silver nanoparticles of varying morphologies by a seeding growth approach at room temperature. Seeds are prepared by reducing silver nitrate with sodium borohydride, and trisodium citrate is used as capping agent. This citrate capped seed sol is added to the growth solution containing ascorbic acid, sodium dodecyl sulphate (SDS) and sodium hydroxide. Colour of the growth solution changes from colourless to pink and the surface plasmon resonance (SPR) shows two distinct bands, indicating the formation of anisotropically grown silver nanostructures. Synthesized silver nanoparticles are characterized by UV-vis spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. Silver nanoseeds are spherical in shape with diameter ranges from 8 to 16 nm. On the other hand, a mixture of morphologies with shapes like triangular and hexagonal nanoplates, nanorods are obtained in the growth solution. XRD results suggest that the particles are crystalline in nature with face centered cubic (fcc) geometry.