Structural, morphological and optical properties of multifunctional magnetic-luminescent ZnO@Fe3O4 nanocomposite

In the present work, non-toxic luminescent ZnO nanoparticles (NPs) and magnetic Fe3O4 NPs were separately prepared by co-precipitation method. In order to get the ZnO@Fe3O4 nanocomposite (NCs), both these NPs were embedded in silica matrix. Powder XRD reveals that the formation hexagonal wurzite structure of ZnO and cubic inverse spinel structure of Fe3O4. Both phases were combined in the prepared ZnO@Fe3O4 NCs. FT-IR spectra showed the absorption peaks confirmed the presence of metal-oxygen stretching bands in ZnO NPs, Fe3O4 NPs and ZnO@Fe3O4 NCs samples. VSM results showed both magnetite and ZnO@Fe3O4 have super-paramagnetic, whereas the saturation value for ZnO@Fe3O4 NCs was tremendously decreased. Photoluminescence (PL) spectra of ZnO and ZnO@Fe3O4 illustrated that both samples have very good luminescence property. PL intensity of ZnO@Fe3O4 NCs has been reduced as compared to the intensity of bare ZnO NPs. However, ZnO@Fe3O4 still hold very good luminescence property. The as-prepared ZnO@Fe3O4 NCs were successfully demonstrated for magnetic resonance imaging contrast agent application. Hence, it can be simultaneously used for MRI contrast agent as well as optical imaging applications.