Cu2O nanowires were synthesized at large scale on copper plate by thermal oxidation in air. The effect of oxidation time and temperature on the morphology of the nanowires was examined. The oxidation time had no effect on the diameter of the nanowires, while it had a great effect on the density and the length of the nanowires. The density and the length of the nanowires increased, and then decreased, with increasing oxidation time. The oxidation temperature had a tremendous effect on the size-distribution as well as the density of the nanowires. When the oxidation temperature was 700˚C, uniform size-distribution and high density of the nanowires was achieved. At lower and higher temperatures, the density of the nanowires was lower, and they displayed a broader size-distribution. It is suggested that the Cu2O nanowires were grown via a vapor-solid mechanism because no catalyst particles were observed at the tips of the nanowires.
Carbon coils could be synthesized using C₂H₂/H₂as source gases and SF6 as an incorporated additive gas under thermal chemical vapor deposition (CVD) system. Prior to the carbon coils deposition reaction, two kinds of samples having different combination of Ni catalyst and substrate were employed, namely, a commercially-made Al₂O₃ceramic boat with Ni powders and a commercially-made Al₂O₃substrate with Ni layer. By using a commercially-made Al₂O₃ceramic boat, the synthesis of carbon coils could be enhanced as much as 10 times higher than that of Al₂O₃substrate. Furthermore, the dominant formation of the microsized carbon coils could be obtained by using Al₂O₃ceramic boat. The surface roughness of the supporting substrate of Al₂O₃ceramic boat was understood to be associated with the large scale synthesis of carbon oils as well as the dominant formation of the larger-sized, namely the microsized carbon coils.