s Formation of Hollow Copper Oxide by Oxidation of Cu Nanoparticles

The formation of hollow Cu oxide nanoparticles through the oxidation process has been studied with Cu nanoparticles produced by the plasma arc discharge method. The initial copper nanoparticles had a size range of 40 - 60 nm and a thin Cu2O layer on the surface. After oxidation at 100°C, there was no significant change in the particles. After oxidation at 200°C, however, the particles consisted of Cu2O and CuO instead of metallic Cu. By further increasing the temperature up to 300°C, only CuO particles remained. The obtained CuO particles had a hollow structure which resulted from the Kirkendall effect.