Morphology alterations during postsynthesis oxidation of Zn nanowires

Zinc metal nanowires have been oxidized at temperatures of 200–500 °C in ambient air in order to obtain ZnO nanowires. X-ray diffraction investigations reveal a complete transformation from Zn to ZnO at a temperature of ≥300 °C within 30 min. Temperature-induced grain growth attains saturation at about 350 °C. Scanning electron microscopy studies show a pronounced morphology change from smooth, unidirectional to rough, bursted nanorods at a temperature of >250 °C. The corresponding transformation mechanism is discussed.