Tunable synthesis and multifunctionalities of Fe₃O ₄-ZnO hybrid core-shell nanocrystals

We report the tunable synthesis and multifunctionalities of Fe ₃O₄-ZnO hybrid core-shell nanocrystals as prepared through controlled sequential nanoemulsion processes. The characterization shows the orderly variations of the structural, magnetic, photoluminescent and absorption properties of the nanocrystals versus the nanoshell thickness. The nanocrystals reveal structural features unique to the core-shell design and exhibit well-defined superparamagnetic behavior at room temperature. In opposite to the decreasing magnetization, both bandgap and induced surface emissions depend strongly on the increasing nanoshell thickness. Moreover, the FTIR analysis provides the fingerprints of the polymer surfactant, ZnO and Fe ₃O₄ in the same nano-entity and the core-shell nanocrystals could be directly dispersed in both aqueous and organic media for application readiness. Aptly tunable in nanostructures and thus optimized properties, this kind of monosized, high quality, and multifunctional core-shell nanocrystals could be of interest for fundamental studies and potential applications.