Magnetic and optical properties of green synthesized nickel ferrite nanoparticles and its application into photocatalysis

Abstract

Spinel NiFe2O4 nanoparticles have been synthesized via hydrothermal route using Mangifera Indica flower extract (MIFE) as a green surfactant and reducing agent. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) have been used to determine the structure and morphology. The formation of single-phase, monodisperse NiFe2O4 with mixed morphology, the predominant shape being of equiaxed nanoparticles having an average particle size ~45 nm, is observed. The thermal magnetization of as-synthesized NiFe2O4 nanoparticles shows ferromagnetic to paramagnetic phase transition at Tc~825K. These nanoparticles show a very high saturation magnetization (Ms) value of 55 emu/g close to the bulk material and amongst the highest reported values for green synthesized NiFe2O4. This material has a coercivity (Hc) of 0.15 kOe and remanent magnetization (Mr) of 8.5 emu/g. The as-synthesized NiFe2O4 nanoparticles show bandgap energy of 2.02 eV, derived from UV-Vis absorption measurement, which is suitable for effective solar photocatalytic reactions. When exposed to sunlight in the presence of as-synthesized NiFe2O4 nanoparticles, 93% of MB-dye degradation is measured in 80 minutes, indicating excellent photocatalytic properties. Based on the as-synthesized NiFe2O4 nanoparticles' observed properties, the effectiveness of MIFE as an environmentally friendly surfactant, and the low-cost dye-degradation prospects of green synthetic NiFe2O4 are affirmed.