Synthesis And Properties Of Noble Metal Based Core/shell Nanostructures Prepared By Excimer Laser Ablation In Liquids

The discovering of new preparation method is an eternal topic of nanomaterial.The core/shell nanostructures, which have the advantage of monodispersion, core/shell operability, stability and self-assembly, have attracted much attention in recent years. The performance of nanostructures depends on its preparation method. Pulsed laser ablation in liquids is a simple, fast, wide adaptability and green method to prepare nanomaterial. This paper aims to study the preparation process, the product of preparation and performance analysis by using 248 nm excimer laser ablation preparing precious metal-based nanostructures in liquid phase.In this paper, based on the preparation of the precious metal nanostructures, precious metal core/shell nanostructures and ZnO nanostructures, a 248 nm excimer laser was used to prepare Ag/ZnO core/shell nanostructures in liquid. High resolution transmission electron microscopy, UV-Vis-NIR spectrophotometer, X-ray diffraction spectra and X-ray photoelectron spectroscopy were used to test the morphology, components and size of the nanostructures. Results showed that, the precious metal core/shell nanostructures and the Ag/ZnO nanostructures have a tuned surface plasmon resonance by the thickness of the shell. It was in agreement with the simulation by the Mie theory.Confocal Raman, photoluminescence and UV irradiation were used to test the surface-enhanced Raman effects, photoluminescence effects and characterization effects of the productions. It showed that, the precious metal core/shell nanostructures prepared by laser ablation have good SERS activities and can be used to detect trace amounts of certain materials. The UV emission of the Ag/Zn O core/shell nanostructures was stronger than ZnO nanoparticles. This was in agreement with the electron transfer theory. The UV emission peak of the Ag/ZnO core/shell nanostructures had a blue shift compared with the ZnO nanoparticles due to the quantum size effect caused by the nanoparticles. What’s more, the Ag/ZnO core/shell nanostructures had a good photocatalytic effects which depend on the content of Ag. What’s more, the mechanism of the preparation of the core/shell nanostructures has been discussed in detail.