Magneto-optical features of Ni-substituted CoFe2O4 nano spinel ferrites and its photocatalytic activity

Abstract

Ni-substituted cobalt ferrite (Co_1-xNi_xFe₂O₄, x = 0.0 to 1.0) nano spinel ferrites (NSFs) with different particle sizes were created using the microwave combustion process with urea fuel. Powder XRD diffraction was used to characterize the acquired spinel ferrites, and HR-SEM and HR-TEM were used to examine the average size and grain shape. Nitrogen adsorption and desorption isotherms are used to estimate the BET-specific surface area, pore size distribution, and pore volume of Co_1-xNi_xFe₂O₄ nanomaterials. The room temperature magnetization of Co_1-xNi_xFe₂O₄ NSFs with various Ni contents (x = 0.2, 0.4, 0.6, 0.8, and 1.0) was measured using VSM (vibrating sample magnetometer). To estimate the catalytic activity of Co_1-xNi_xFe₂O₄ NSFs_, the degradation of 4-NP has been studied with NaBH₄ at room temperature. Moreover, reduction reactions are achieved with 2 ×10^-5 M of sodium borohydride (NaBH₄) and Co_1-xNi_xFe₂O₄ with NSF catalysts. CoFe₂O₄ shows zero activity in the reduction reaction. Surprisingly, it has been perceived that the catalytic efficiency is improved with the introduction of Ni content with CoFe₂O₄ lattice. Among all compositions, Co_0.8Ni_0.2Fe₂O₄ shows a maximum rate constant. Different mechanisms are investigated using the acquired results, and their relevance to magnetism and structure is explained.