Silver nanoparticles supported on alpha-, eta- and delta-alumina

Silver monodispersed nanopaticles supported on alpha- and eta-Al2O3 have been obtained by a colloidal processing route. Precursor (silver acetate) was transformed into Ag metallic nanoparticles deposited on Al2O3 powder after a drying and reduction process. Silver particle size varies between 100 and 1 nm depending on the alumina phase. On the basis of HRTEM studies, and according to the nature of alumina surface, a mechanism of nucleation and growth of silver nanoparticles has been proposed. Finally, optical spectra of these samples revealed the presence of silver surface plasmon, which supplies information about the dispersion of nanoparticles into alumina matrices. (c) 2004 Elsevier Ltd. All rights reserved.