Nanoparticles of metal and metal oxides: some peculiar synthesis methods, size and shape control,application to catalysts preparation

摘要

One step (direct) and multisteps synthesis methods of metal and oxide nanoparticles are presented includingboth bottom-up and top-down procedures. Chemical methods involving the polyol process allows to get eitherisotropic or anisotropic nanoparticles. Nanowires, nanorods and dumbells can be generated either by hetero-geneous nucleation or by using a template (mesoporous silica). Top-down procedures are illustrated by laserirradiation of immersed bulk targets (Ag, Au) which generates self-organized nanostructures or colloidal solu-tions. Laser irradiation of these colloidal solutions modifies the size distribution and the shape of nanoparticles.Bimetallic nanoparticles are generated from mixtures of monometallic colloidal solutions. Surface-mediatedmethods involving a host support and an invited phase are also presented. They lead to the formation of metalor oxide clusters and nanoparticles. The speciation of these entities is correlated with the observed catalyticperformances