Synthesis and characterization of Cu/SiO2−x composite nanowires

Abstract Copper/silica-based nanostructures with different morphologies and microstructures have been synthesized on Si wafer by thermal evaporation of CuO and SiO powders in an argon-hybridized hydrogen ambient at high temperatures. Systematically studies by scanning electron microscopy with field emission gun and transmission electron microscopy show that the composite nanowires have a core–shell structure with an average diameter of ∼120 nm and lengths of several hundred nanometers to several ten microns. Electron diffraction pattern and electron energy dispersive X-ray spectroscopy analysis reveal that the core coincides with copper and the shell corresponds to amorphous silicon oxide with chemical composition SiO 2− x (0≦ x ≦0.5). Besides the Cu/SiO 2− x nanowires, many other nanostructures such as octpous-, pine-, and chain-like structures have also been found. The growth mechanisms of these products were briefly discussed.