Application of nanocrystalline spinel MFe2O4, (M = Co and Cu) in waste water treatment

Abstract

Abstract Transition metal spinel ferrites MFe2O4 (M = Cu and Co) were successfully synthesized following the co-precipitation method and their structural, optical, photocatalytic, antimicrobial and toxicity properties have been studied. The characterization of the title compound has been carried out using XRD, SEM, EDS, FT-IR and UV spectroscopy. The XRD studies confirmed a cubic spinel structure with the Fd-3m space group and CuFe2O4 and CoFe2O4 exist in the nanocrystalline size of 43 nm and 17 nm, respectively. The SEM images revealed the agglomerated nature of the ferrite nanoparticles, and the EDAX spectrum confirmed the elemental compositions of the samples and their purity. The FT-IR spectra indicated the presence of metal–oxygen stretching bands. The ferrite samples demonstrated photocatalytic activity in the visible region, as assessed by the degradation of methylene blue (MB), in an aqueous solution under visible irradiation. After 105 minutes, CuFe2O4 and CoFe2O4 catalysts exhibited degradation of 72% and 56% for the MB solution. Through broth dilution, MFe2O4 (M=Cu and Co) nanoparticles were evaluated for their antimicrobial activity using S. aureus and E. coli, as well as gram-positive and gram-negative bacteria. Studies indicated that CoFe2O4 nanoparticles exhibit better antibacterial activity when compared to CuFe2O4. However, the antifungal activity study indicated that CuFe2O4 nanoparticles exhibit better antifungal activity when compared to CoFe2O4 nanoparticles. The toxicity of the nanomaterials was tested by mixing MFe2O4 (M = Cu and Co) with food and administering it orally to Drosophila melanogaster. The results indicated that the functionalized CuFe2O4 nanoparticles are non-toxic for the living organisms. Hence, optimized NCs have the potential for degrading dyes from polluted water as well as acting as antimicrobial agents by rupturing the cells of pathogens. They have potential applications in both environmental safety and biomedicine.