Facile Synthesis of Fe₃O₄/ZnO Nanocomposite: Applications to Photocatalytic and Antibacterial Activities

In the current work, we have reported the preparation of Fe₃O₄/ZnO nanocomposite (NC) via co-precipitation. The prepared Fe₃O₄/ZnO nanocomposite were characterized by x-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) equipped with energy dispersive x-ray analysis (EDAX), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface area analysis, ultraviolet-diffuse reflectance spectroscopy (UV-DRS) and photoluminescence spectroscopy (PL). From the x-ray diffraction pattern, the average crystallite size of Fe₃O₄/ZnO NC was found to be 13 nm. UV-DRS showed an energy band gap of 2.3 eV for the prepared sample. From the Brunauer–Emmett–Teller (BET) surface area analysis, total pore volume (V_P) and mean pore diameter (r_p) were found to be 12.647 m²g⁻¹, 0.024125 cm³g⁻¹ and 7.6302 nm. The functional groups and metal to oxygen bonding in Fe₃O₄/ZnO NC were observed in FT-IR. SEM and TEM micrograph of Fe₃O₄/ZnO NC show flake- and grain-like structures, and the luminescence spectrum shows blue emission. The photocatalytic activity of Fe₃O₄/ZnO NC was examined using industrial effluent dyes such as Evans blue (90% in 150 min) and Rhodamine B (RB) (99% in 150 min) under UV light irradiation. Further, Fe₃O₄/ZnO NC also showed a superior zone of inhibition against pathogenic bacterial strains such as Escherichia coli and Staphylococcus aureus by agar well diffusion compared to Fe₃O₄ and ZnO nanoparticles.