Photostability of gold nanoparticles with different shapes: role of Ag clusters

M. ARTURO LÓPEZ-QUINTELA; F.G. REQUEJO; L. J. GIOVANETTI; DAVID BUCETA; YASSER A. ATTIA

Nanoscale

Royal Society of Chemistry

Lugar: London; Año: 2015 vol. 7 p. 11273 - 11279

2040-3364

Anisotropic gold nanostructures prepared by the seed method in the presence of Ag ions have been used to study their photostabil- ity to low-power UV irradiation (254 nm) at room temperature. It has been observed that, whereas spheres are very stable to photo- irradiation, rods and prisms suffer from photocorrosion and finally dissolve completely with the production of Au(III) ions. Interpret- ation of these differences is based on the presence of semiconduc- tor-like Ag clusters, adsorbed onto rods and prisms, able to photocorrode the Au nanoparticles, which are absent in the case of Au spheres. We further show direct evidence of the presence of Ag clusters in Au nanorods by XANES. These results confirm a pre- vious hypothesis ( J. Am. Chem. Soc., 2014, 136, 1182?1185) about the major influence of very stable small Ag clusters, not only on the anisotropic formation of nanostructures but also on their photostability.