The Synthesis And Near-IR Light Manipulated Catalytic Study Of Rare Earth Upconversional Super Nanomaterial

Core-satellite structure is one of the most charming super structures for its easy fabrication and facie integration of different materials to obtain enhanced or completely new properties. Here we reported the fabrication of a novel ceria-based core-shellsatellite supersandwich nanostructure with NIR light manipulated catalytic activity that fancily integrated the upconversion luminescent property and catalytic function of CeO₂ nanoparticles with different sizes. Specifically, lanthanide-doped large CeO₂ nanoparticles was coated with a layer of silica（o-CeO₂@SiO₂）, and small CeO₂ nanocubes（c-CeO₂） was then assemble on the surface of o-CeO₂@SiO₂（oCeO₂@Si O₂@c-CeO₂）. In this supersandwich structure, the upconversion luminescent intensity of CeO₂ nanoparticles was enhanced by nearly 2 times for the first time by silica layer. Additionally, o-CeO₂@SiO₂@c-CeO₂ also possessed excellent pHdependent catalytic activities. Furthermore, the NIR light manipulated catalytic performance of this supersandwich nanostructure based catalyst was deeply investigated after depositing gold nanoparticles on the outside c-CeO₂. The resultant supersandwich nanocomposites were capable of efficiently catalyzing the selective reduction of aromatic nitro compounds into corresponding azo compounds under nearinfrared（NIR） light irradiation. More importantly, the nanocomposites could also effectively utilize both NIR and visible region of sunlight for the green synthesis of aromatic azo compounds.