Preparation of Cu2O nanowires by thermal oxidation-plasma reduction method

Facial synthesis of cuprous oxide (Cu₂O) nanowires by directly heating copper substrates is difficult; however, in this study, it was successfully done by thermal oxidation followed by a plasma reduction process. The preparation of CuO nanowires with an average diameter of 76.2?nm supported on the surface of copper substrate was conducted first in air at 500?°C for 3?hrs, and then the CuO nanowires were reduced into Cu₂O in 15?min using either radio frequency (RF) N₂ plasma or microwave (MW) N₂ plasma. The characteristics of CuO and Cu₂O nanowires were analyzed using XRD, FE-SEM, and TEM. The results showed that Cu₂O nanowires can be successfully reduced from CuO nanowires by a simple, promising, and fast nitrogen plasma process. Moreover, in RF plasma, narrower and longer Cu₂O nanowires can be produced as compared to MW plasma, because energetic N-containing species can reduce the nanowires at a relatively lower temperature.