This work reports the change in shape from spheres into disks and prisms of silver nanoparticles. The conversion was possible by controlling the concentration of trisodium citrate during a photoconversion process that occurred with different concentration of of Agxitrate ratio (namely 1:1, 1:2,1:3). The nanoparticles were processed by using magnetic stirring and visible light. It was found that the formation of silver nanodisks was found to be sensitive to the citrate concentration, as it is revealed by UV-Vis spectra. Bigger amounts of citrate produced sharper tips in the prisms; all these effects were witnessed by means of the HRSEM analysis, which showed 30 nm disks and 50 ran prisms.
INTRODUCTION:
Research in nanomaterials has caught the attention of material science as silver and gold nanomaterials offer have interesting chemical and physical properties that can be used in optical, electronic, magnetic and catalytic fields.' One of the characteristics of metallic nanoparticles is their anisotropic optical absorption, which is associated to collective oscillations of conduction electrons. This phenomenon is known as surface plasmon resonances (SPR), and it is of high importance in the production of nanophotonic devices and circuits. An important aspect of SPR is its sensitivity to the size and shape of nanoparticles, and these characteristics, as well as their composition, are of paramount importance to determine SPR of metallic nanoparticles.
There is work reported on the change in shape of silver nanoparticles. Thermal ' and photochemical 1,s treatments are two typical approaches for the morphological modification of silver nanoparticles. Xia et al. 6 reported the formation of triangular silver nanoplates in presence 35