Preparation And Optical Characterization Of ZnO/Au Nanocomposites

Nanosized Zinc Oxide-metal composite materials have been increasingly popular in many scientific and industrial communities because of their novel optical, electrical and mechanical properties. Here we have synthesized semiconductor-metal nanocomposites of ZnO/Au, and realized the transfer of ZnO nanoparticles from enthanol to aqueous phase by depositing Au on ZnO nanoparticles. At the same time, there exists the enhanced built-in electrical field in ZnO nanoparticle resulting from electron transfer from ZnO to Au nanoparticle. So we analyzed the effect of interfacial charge transfer on the optical properties of resonant Raman scattering (RRS) and photoluminescence (PL) of ZnO nanoparticle. The research should be useful for the application of ZnO nanoparticles in photocatalysis and bio-detection.This thesis includes the following three parts:(1) We investigated the effect of Ostwald ripening, aggregation, annealing, storing under the atmosphere, etc. on the optical properties and structure stability of ZnO nanoparticles by the variety of optical spectra. And we have concluded that ZnO nanoparticles under Ostwald ripening for 1～10 days are optimal for the synthesis and the further application of ZnO/Au nanocomposites, where ZnO nanoparticals are the core of Au reacting process.(2) By controlling the stoichiometric ratiol of HAuCl4 and trisodium citrate where ZnO nanoparticals are the core of Au reacting process, we synthesised the ZnO/Au nano- composites where different amount of Au nanoparticles are deposited on ZnO nanoparticles of nearly the same sizes.(3) We analyzed the effect of interfacial charge transfer on the optical properties, such as RRS and PL of ZnO/Au nanocomposites.The aforementioned research should ultimately improve the potential applications for ZnO and Au nanoparticles in photocatalysis and bio-detection.