Fabrication of Hollow Nano Particles of Metallic Oxides through Oxidation Process

The formation mechanisms of hollow metal oxide through the oxidation of several metal nanoparticles have been studied by transmission electron microscopy. For Zn, Al, Cu, Ni and Fe nanoparticles, hollow oxide nanoparticles were obtained as a result of vacancy aggregation in the oxidation processes. The formation of the hollow morphology is attributed to the faster outward diffusion of metal ions through the oxide layer in the oxidation processes. Further changes in morphology during the annealing of hollow Cu, Ni and Fe oxides at higher temperatures in air were examined.