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

Abstract

Cobalt-doped bismuth ferrite (Bi_1-xCo_xFeO₃) 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 Bi_1-xCo_xFeO₃ 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 Bi_1-xCo_xFeO₃ nanoparticles are ferromagnetic at room temperature. The strength of magnetization increased with an increase of Co doping concentration. Photocatalytic properties of the Bi_1-xCo_xFeO₃ nanoparticles were studied using a UV–Vis-NIR spectrophotometer, and it was found that Bi_1-xCo_xFeO₃ 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 Bi_1-xCo_xFeO₃ nanoparticles at x = 0.07 exhibited the highest photocatalytic activity (97.9%).