Multifunctional Core-Shell NiFeO Shield with TiO/rGO Nanostructures for Biomedical and Environmental Applications.

Multifunctional core@shell nanoparticles have been synthesized in this paper through 3 stages: NiFeO nanoparticles by microwave irradiation using leaf extract as a fuel, core@shell NiFeO@TiO nanoparticles by sol-gel, and NiFeO@TiO@rGO by sol-gel using preprepared reduced graphene oxide obtained by modified Hummer's method. XRD analysis confirmed the presence of both cubic NiFeO spinel and tetragonal TiO rutile phases, while Raman spectroscopy analysis displays both and bands ( /  = 1.04) associated with rGO. Morphological observations by HRTEM reveal a core-shell nanostructure formed by NiFeO core as confirmed by SAED with subsequent thin layers of TiO and rGO. Magnetic measurements show a ferromagnetic behavior, where the saturation magnetization drops drastically from 45 emu/g for NiFeO to 15 emu/g after TiO and rGO nonmagnetic bilayers coating. The as-fabricated multifunctional core@shell nanostructures demonstrate tunable self-heating characteristics: rise of temperature and specific absorption rate in the range of Δ = 3-10°C and SAR = 3-58 W/g, respectively. This effectiveness is much close to the threshold temperature of hyperthermia (45°C), and the zones of inhibition show the better effective antibacterial activity of NTG against various Gram-positive and Gram-negative bacterial strains besides simultaneous good efficient, stable, and removable sonophotocatalyst toward the TC degradation.