The investigation of a hydro-thermal method to fabricate Cu@C coaxial nanowires and their special electronic transport and heat conduction properties†
A hydro-thermal method for the preparation of single-crystalline copper@carbon nanowires (Cu@C NWs) with outer diameters between 60 and 120 nm and lengths ranging from 5 μm up to 20 μm is reported. After an oxygen feeding treatment of the copper core the carbon wrapped Cu-cable is transformed into an empty carbon nanotube. We show that there is dissolution–deposition dynamic balance within the carbon shell, which involves the Cu in a reversible filling–emptying process repeatedly. The obtained nanowires were characterized by scanning electron microscopy (SEM), tunneling electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy respectively. In addition, electronic transport properties of single nanowires and enhancement in thermal conductivity of thermal grease modified by as-prepared Cu@C nanocomposites have also been discussed.