Spinel ferrite of MnFe2O4 synthesized in Piper betle Linn extract media and its application as photocatalysts and antibacterial

The manganese spinel ferrite (MnFe2O4) particles were successfully synthesized via a hydrothermal route in green betel leaf (Piper betle Linn) extract media. Morphology, structure, and characteristics of the samples were analyzed by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), X-Ray Diffraction (XRD), Fourier-Transform Infrared (FT-IR), Diffuse Reflectance Spectroscopy UV-Vis (DRS UV-Vis), and Vibration Sample Magnetometer (VSM) instruments. Photocatalytic activity of the spinel ferrite was evaluated by the degradation of dye under solar light and antibacterial activity was studied with different strains of Gram-positive and Gram-negative bacteria. The results revealed that the concentration of betel leaf extract was an important factor, which affects the morphology, crystallization, and magnetic properties of MnFe2O4. The prepared samples exhibited soft-ferromagnetic behavior at room temperature. Un-calcined samples showed higher saturation magnetic (similar to 65 emu/g) than calcined samples (29-41 emu/g). The band gap energy of synthesized samples was about 2.05 eV. Two major wide-ranging metal-oxygen (M-O) peaks are seen in the FT-IR spectra in the range of 570-300 cm(-1), which confirmed the presence of tetrahedral and octahedral sites in the spinel structure. The MnFe2O4 particles showed effective photodegradation for Direct Red 81 dye under solar light irradiation. Moreover, the prepared samples exhibited significant activity as an antibacterial against Staphylococcus aureus and Escherichia coli.