Synthesis and characterization of nanoparticles with magnetic core and photocatalytic shell: Anatase TiO2–NiFe2O4 system

Reverse micelle and hydrolysis have been combined to synthesize anatase-titania coated nickel ferrite nanoparticles of size 10–20 nm. The paper describes the magnetic behavior studied by superconducting quantum interference device and the photocatalytic activity. The anatase TiO2-coated NiFe2O4 nanoparticles retain the characteristics of uncoated nanocrystalline nickel ferrites; superparamagnetism (absence of hysteresis, remanence and coercivity at 300 K) and non-saturation of magnetic moments at high field. The magnetic measurements indicate reduction of magnetization of the anatase TiO2-coated NiFe2O4 nanoparticles compared with the uncoated NiFe2O4 nanoparticles because of the contribution of the volume of the non-magnetic coating layer to the total sample volume. Anatase TiO2-coated NiFe2O4 nanoparticles exhibit photocatalytic nature that can be exploited for antimicrobial activity.