RESUMO
The sol-gel method was employed to prepare nano CoFe2O4 and silver-substituted CoFe2O4 nanohybrids (CoAgxFe2-xO4, x = 0, 0.1, 0.2, 0.3, 0.4) utilizing Moringa oleifera gum as biofuel. The morphology, size, shape, magnetic, optical, and functional groups of the crystallites were determined using various techniques such as UV-visible, Fourier transform infrared, X-ray diffraction, Rietveld, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and photoluminescence. The produced nanoferrite has a spherical shape with cubic spinal structures. The optical properties were investigated in two different bands in the photoluminescence emission spectra at 469 and 493 nm. Saturation magnetization (Ms) and coercivity (Hc) decrease as the Ag content increases significantly. Furthermore, antibacterial (Gram-positive bacteria bacterial strains, Bacillus subtilis and Staphylococcus aureus, and Gram-negative bacterial strains, Pseudomonas aeruginosa, and Escherichia coli), antibiofilm activity (E. coli), and antioxidant (DPPH) activities were investigated. The substantial increase in the silver content offers a constructive impact on studied biomedical activities. These findings encourage additional research into the use of hybrid nanoparticles (an amalgamation of ferrite and a noble metal) in biomedical and pharmaceutical applications.
RESUMO
TiO2 (0-10 wt %)-doped nanocrystalline Ni0.4Cu0.3Zn0.3Fe2O4 (Ni-Cu-Zn) ferrites were synthesized using the sol-gel route of synthesis. The cubic spinel structure of the ferrites having the Fd3m space group was revealed from the analysis of Rietveld refined X-ray diffraction (XRD) data. The secondary phase of TiO2 with a space group of I41/amd was observed within the ferrites with doping, x > 3 wt %. The values of lattice parameter were enhanced with the addition of TiO2 up to 5 wt % and reduced further for the highest experimental doping of 10 wt %. Field emission scanning electron microscopy (FESEM) images exhibit the spherical shape of the synthesized particles with some agglomeration, while the compositional purity of prepared ferrite samples was confirmed by energy-dispersive X-ray spectroscopy (EDX) and elemental mapping. The cubic spinel structure of the prepared ferrite sample was confirmed by the Raman and Fourier transform infrared (FTIR) spectra. UV-visible diffuse reflectance spectroscopy was utilized to study the optical properties of the ferrites. The value of band gap energy for the pristine sample was less than those of the doped samples, and there was a decrement in band gap energy values with an increase in TiO2 doping, which specifies the semiconducting nature of prepared ferrite samples. A magnetic study performed by means of a vibrating sample magnetometer (VSM) demonstrates that the values of saturation magnetization of the ferrites decrease with the addition of TiO2 content, and all investigated ferrites show the characteristics of soft magnetic materials at room temperature. The Mössbauer study confirms the decrease in the magnetic behavior of the doped ferrites due to the nonmagnetic secondary phase of TiO2.