Preparation of core–shell Ag@CeO₂ nanocomposite by LSPR photothermal induced interface reaction

The core–shell structure of Ag@CeO₂ was prepared by a novel and facile method, which was based on the photothermal effect of localized surface plasmon resonance (LSPR). Nanoparticles (NPs) of Ag were dispersed in a solution containing citric acid, ethylene glycol and cerium nitrate, then under irradiation, Ag NPs generated heat from LSPR and the heat-induced polymerization reaction in the interface between Ag and the sol resulted in cerium gel formation only on the surface of the Ag NPs. After calcination, Ag@CeO₂ was successfully obtained, then Ag@CeO₂/SiO₂ was prepared by loading Ag@CeO₂ on SiO₂. The resultant catalyst exhibited favorable activity and stability for CO oxidation. The preparation method proposed here should be extendable to other composites with metallic cores and oxide shells in which the metallic nanoparticle possesses LSPR properties. (paper)