Magnetic and optical properties of green synthesized nickel ferrite nanoparticles and its application into photocatalysis
Deepak Kumar Dinkar, Bijoy Das, R. Gopalan, Brijnandan S. Dehiya
Abstract
Abstract Spinel NiFe 2 O 4 nanoparticles have been synthesized via hydrothermal route using Mangifera indica flower extract (MIFE) as a green surfactant and reducing agent. X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques have been used to determine the structure and morphology. The formation of single-phase, monodispersed NiFe 2 O 4 with mixed morphology, the predominant shape being of equi-axed nanoparticles having an average particle size ≲45 nm, is observed. The thermal magnetization of as-synthesized NiFe 2 O 4 nanoparticles shows ferromagnetic to paramagnetic phase transition at T c ∼ 825 K. These nanoparticles show a very high saturation magnetization ( M s ) value of 55 emu g −1 close to the bulk material and amongst the highest reported values for green synthesized NiFe 2 O4 nanoparticles. This material has a coercivity ( H c ) of 0.15 kOe and remanent magnetization ( M r ) of 8.5 emu g −1 . The as-synthesized NiFe 2 O 4 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 NiFe 2 O 4 nanoparticles, 93% of MB-dye degradation is measured in 80 min, indicating excellent photocatalytic properties. Based on the as-synthesized NiFe 2 O 4 nanoparticles’ observed properties, the effectiveness of MIFE as an environmentally friendly surfactant, and the low-cost dye-degradation prospects of green synthesized NiFe 2 O 4 nanoparticles are affirmed.