Synthesize and characterization of copper doped nickel ferrite nanoparticles effect on magnetic properties and visible light catalysis for rhodamine dye degradation mechanism

Copper doped NiFe2O4 spinel nanoparticles were prepared by facile microwave combustion method. The X-ray diffraction patterns showed that Cu-doping into NiFe2O4 spinel induced the formation of secondary alpha-Fe2O3 phase along with existing cubic structure. The cubic structure spinel nanoparticles possessed an average crystallite size in the range of 20 - 42 nm. The surface changes were evaluated using Zeta potential, it is found that Cu-doping NiFe2O4 spinel system can induce a negative shift in the flat-band potential and increases the isoelectric point 5.38-7.31. X-ray photoelectron spectroscopy (XPS) peak areas are often used to quantify the elemental compositions and oxidizing states of Cu-doped NiFe2O4 spinel materials surface. Morphological observations using scanning electron microscopy showed irregular shape with severe ag-glomerated distinct grain boundaries were occurred. An optical study, the band gap was found to decrease with an increase in the Cu2+ doping fraction. The presence of FT-IR spectra revealed bands at approximate to 548, 514 and 649 cm-1 were associated to the Ni-O (octahedral site) and Fe-O (tetrahedral site) stretching modes of Cu-doped NiFe2O4 spinel cubic structure. Magnetization-Field (M-H) hysteresis loops of Cu-doped NiFe2O4 spinel nanoparticles were exposed the appearance of soft ferromagnetic behavior at room temperature. The as-fabricated Cu-doped NiFe2O4 spinel nanoparticles were investigated for their superior photocatalytic degradation of rhodamine B under visible light irradiation for atmospheric conditions. It was found that the Cu-doping significantly enhanced the photocatalytic performance of bulk NiFe2O4. Moreover, with the in-creased ratio of Cu-doping into x = 0.4 up to an optimal value, the photocatalytic activity was maximized (efficiency increased from 88.26%, x = 0-99.85%, x = 0.4). The possible photocatalytic mechanism was cri-tically discussed.(c) 2023 Elsevier B.V. All rights reserved.