Synthesis and Photocatalytic Performance of Cobalt-Doped Nickel Ferrites for Dye Degradation

Abstract

This study investigated cobalt-doped nickel ferrites as photocatalysts for dye degradation. The cobalt-doped nickel
ferromagnetic nanoparticles were synthesized using the co-precipitation method. The band gap was measured with a
UV-Vis spectrophotometer, revealing values between 2.32 eV and 2.20 eV. The spinel structure of the ferrites was
characterized through X-ray diffraction (XRD). Scanning electron microscopy (SEM) was employed to ascertain the
morphology and average size of the synthesized nanoparticles. Fourier transform infrared spectroscopy (FTIR)
confirmed metal-oxygen bonds in the range of 400–1000 cm⁻¹. The photocatalytic degradation of dyes under UV
radiation and direct sunlight was evaluated, demonstrating a degradation efficiency of approximately 72% to 92% for
methylene blue within the first 100 minutes, attributed to the active octahedral and tetrahedral lattice sites that
minimize electron-hole recombination. The photocatalytic activity of Co-NiFe₂O₄ was assessed using methylene blue
(MB) and various textile dyes, establishing it as an effective photocatalyst for sewage treatment.