Green-synthesis of Ni-Co nanoferrites using aloe vera extract: Structural, optical, magnetic, and antimicrobial studies

Nickel-doped cobalt nanoferrites (NixCo1-xFe2O4, where x = 0.0 to 1.0 with step size 0.2) were prepared using the auto combustion method in which aloe vera extract was taken as a fuel. Further, characterization for antimicrobial, structural, optical, and magnetic studies was performed for the prepared ferrite nanoparticles. Antimicrobial activity was assessed against a prevalent human fungal pathogen, Candida albicans. The X-ray diffraction (XRD) pattern confirmed the spinel cubic phase with an average crystallite size of 28 nm. The Fourier transform infrared spectroscopy (FTIR) confirmed the stretching mode of vibration at the tetrahedral and the octahedral sites. Further, the analysis of magnetic properties was done using vibrating sample magnetometer (VSM), and the magnetic parameters, specific magnetization (67.69 emu/g) as well as squareness ratio sigma(R)/sigma(S) (0.47) were observed. From the UV-Visible absorbance spectra, the absorbance band edge was observed between 700 and 800 nm, and band gap values were observed at 2.84 eV for x = 1.0. Furthermore, the antimicrobial studies of the obtained ferrite nanoparticles were inspected against the C. albicans fungi, and it was observed that nickel-doped cobalt ferrite shows an inhibitory nature. Maximum inhibition of 0.43 (67% growth) was observed for the composition x = 1.0. Therefore, these ferrite nanoparticles can be used as a drug against fungus infection.