Preparation of size-controllable (Cu-ZnO)@C core- and yolk-shell nanoparticles

C.-I. Hong, H.Y. Kang, F-C Chang, H.P. Wang
National Cheng Kung University, TW

Keywords: size-controllable, Cu-ZnO@C, EXAFS, XANES


Size-controllable Cu-ZnO@C core-shell nanoparticles having diameters of 7-20 nm were prepared by carbonization of Cu2+- and Zn2+-CD (Cu-to-Zn ratio=0.1-1) at 343-573 K for 2 hrs. By XRD, the major compounds in the Cu-ZnO@C core-shell nanoparticles are metallic copper (Cu) and ZnO. Cu2O is not observed. The TEM images indicated the Cu-ZnO@C core-shell nanoparticles having Cu diameters of 7-20 nm are nearly in a spherical shape and isolated individually. By in situ small angle X-ray scattering (SAXS), the diameter fittings of Cu-ZnO@C nanoparticles are consistent with the TEM and XRD observations. After etching of Cu from Cu-ZnO@C, Cu in the carbon shells having diameters of 3-14 nm is observed. X-ray absorption near edge structure (XANES) spectra of Cu in the Cu-ZnO@C core- and yolk-shell nanoparticles indicates the existence of tunable size of Cu and ZnO.