Thermal reduction route to the fabrication of coaxial Zn/ZnO nanocables and ZnO nanotubes

Coaxial Zn/ZnO nanocables and ZnO nanotubes have been fabricated via a thermal reduction route using ZnS powder as the source material. The samples were characterized using X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry. The as-synthesized Zn/ZnO nanocables consisted of a metallic core (Zn) approximate to50 nm in diameter and a semiconductor outer shell (ZnO) approximate to5 nm in thickness and several micrometers in length. A good epitaxial relationship between the Zn core and ZnO shell was observed, and misfit dislocations were observed at the Zn/ZnO interface, which accommodated the relatively large lattice mismatch. The outer diameter and wall thickness of the ZnO nanotubes are approximate to60 and approximate to10 nm, respectively. The possible formation mechanisms for the Zn/ZnO nanocables and ZnO nanotubes are discussed.