The synthesis and optical properties of the heterostructured ZnO/Au nanocomposites

ZnO/Au heterostructured nanoparticles were formed through epitaxial growth of Au on the ZnO seeds. The morphology and structure of ZnO/Au nanocomposites were investigated by TEM and XRD analysis. The nanocontact between Au and ZnO results in red-shift of surface plasmon of the Au and increase the intensity of Raman signals of ZnO. Heterostructured ZnO/Au nanocomposites also enhance chemical stability of ZnO in aqueous solution.

HRTEM image shows that single ZnO nanoparticle has been connected with Au nanoparticle. The resonant Raman scattering spectra of ZnO/Au nanocomposites with increasing the amount of Au were changed. The enhancement is predominant for the first-order LO phonon mode of ZnO. The enhancement of surface optical phonons in RRS experiments can be rationalized by the fact that surface optical phonons execute vibrational motion only within a few atomic layers near the surface, and the Raman scattering volume of this mode can entirely be subjected to the electromagnetic interaction with the Au surface plasmon.Figure optionsDownload as PowerPoint slide