Synthesis of Metal Oxide Hollow Nanoparticles by Chemical Vapor Condensation Process

The influence of reaction temperature on phase evolution of iron oxide hollow nanoparticles during chemical vapor condensation (CVC) process using iron acetylacetonate was investigated. X-ray diffraction (XRD) analyses revealed that three iron oxide phases (α-Fe2O3, γ-Fe2O3, and Fe3O4) and a mixture of β-Fe2O3 and small amount of γ-Fe2O3 were synthesized at 700oC and 900oC, respectively. TEM observation disclosed that the iron oxide particles are almost composed of hollow structured nanoparticles of 10~20 nm in size and 3~5 nm in shell thickness. This result implies that reaction temperature determining various reaction parameters plays an important role for the phase- and structural evolutions of iron oxide hollow nanoparticles. Especially, the present investigation attempted to explain temperature dependence of the phase evolution of β-Fe2O3 hollow nanoparticles in association with the decomposition of iron acetylacetonate.