Synthesis, characterization and environmental remediation studies of Bi-substituted Li-Co spinel ferrites

Abstract

Photocatalytic ability of Lithium-Cobalt ferrites was improved by doping with Bi. For the synthesis of different compositions of Bi-doped Li-Co Ferrites, the Micro-Emulsion method was used. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) and Scanning Electron Microscopy (SEM) analyses confirmed its spinel structure and morphology. Bi-substituted Li-Co ferrites exhibit 93.8% and 83.9% degradation of methylene blue and crystal violet, respectively. While using scavenger this value of degradation of crystal violet exceeds up to 98.5%. The rate constants of LiCo0.5Bi0.4Fe1.6O4 for methylene blue (MB) and crystal violet (CV) are 0.0203 and 0.01615 min−1, respectively. The band gap energy value calculated using tauc plot is 2.70 eV and 3.95Ev for Li-Co ferrites and Bi-doped Li-Co ferrites, respectively. Electrochemical impedance spectroscopy (EIS) studies confirmed that the doping of Bi in Li-Co spinel ferrites enhances its conductance. The use of these ferrites for photocatalytic degradation is more beneficial because they can be easily separable afterwards due to their magnetic nature which is confirmed by studying the re-usability of the as-synthesized samples. Highlights Li-Co ferrites and Bi-substituted Li-Co ferrites were synthesized by the micro-emulsion method. XRD and FTIR confirmed their spinel structural features. The prepared catalyst successfully degraded the MB (> 90%) and CV (> 80%). Antibacterial studies of as-synthesized samples were also done for S. aureus (Positive Strain) and P. aeruginosa (Negative Strain) microorganisms.