Photochemical synthesis of different silver nanostructures

Many silver nanostructures (e.g., triangular nanoprisms, nanorods) may be synthesized using photochemical reactions. Up to now such photochemical transformations of silver nanoparticles have been always carried out in the presence of dissolved oxygen. In this contribution we have shown that plasmon-driven transformation of silver nanoparticles can be carried out in the deoxidised solutions. We have also shown that light-induced transformations of silver nanoparticles may be used for creation of nanoaggregates, which are very efficient nanoresonators for surface-enhancement Raman scattering (SERS) measurements. In contrast to the chemical methods of aggregation, in the photochemical aggregation there is no need to introduce additional compounds as aggregation agents. The mechanism of light-induced aggregation of silver nanoparticles will be discussed. The photochemical growth of different silver seed nanoparticles has been also analyzed. To exclude possible differences in the growth of various silver seed nanoparticles caused by different blocking effects of various crystallographic facets by different adsorbates, all used silver seed nanoparticles (spherical, flat and elongated) have been prepared using the same set of compounds. Although the photochemical reactions have been carried out in the same conditions, the initial small difference in the shape of silver seed nanoparticles leads to formation of significantly different nanostructures.