Structural, Magnetic, and Dielectric Properties of Bi1-xCoxFeO3 Nanoparticles for Photocatalytic Application

Cobalt-doped bismuth ferrite (Bi1-xCoxFeO3) nanoparticles (NPs) at x = 0.00, 0.03, 0.07 were synthesized using the sol-gel auto-combustion method and studied the influence of cobalt (Co) on structural, surface, chemical, optical, magnetic, and photocatalytic properties on Bi1-xCoxFeO3 nanoparticles. X-ray diffraction (XRD) studies revealed the rhombohedral structure of the synthesized nanoparticles with a mean crystallite size of 51 nm. Using Tauc's relation, the optical band gap was calculated, and it decreased from 2.13 to 1.6 eV with increased Co concentration. The iron-oxygen (Fe-O) stretching vibrations were confirmed from Fourier transform infrared (FT-IR) spectra. Magnetic properties of the nanoparticles were studied using a vibrating sample magnetometer and found that Bi1-xCoxFeO3 nanoparticles are ferromagnetic at room temperature. The strength of magnetization increased with an increase of Co doping concentration. Photocatalytic properties of the Bi1-xCoxFeO3 nanoparticles were studied using a UV-Vis-NIR spectrophotometer, and it was found that Bi1-xCoxFeO3 nanoparticles can be used as a photocatalyst in the visible region of the spectrum. Methyl blue (MB) dye was used to study the dye degradation property of pure and Co-doped BiFeO3 nanoparticles, and the results were explained in detail. The Bi1-xCoxFeO3 nanoparticles at x = 0.07 exhibited the highest photocatalytic activity (97.9%).