Synthesis of Wormlike α-Fe2O3 Nanostructure: Characterization and Antibacterial Application

Abstract

Wormlike iron oxide nanostructures were synthesized via a simple hydrothermal route for antibacterial application. The synthesized samples were characterized using different techniques for determining the morphology, elemental composition, crystal structure, magnetization, and optical properties. Field-emission scanning electron microscope images confirmed the formation of wormlike nanostructures. The mean diameter of wormlike particles was estimated to be around 30 nm. The x-ray diffraction pattern of the synthesized sample showed the formation of α-Fe2O3 or hematite with a rhombohedral lattice system and Raman spectroscopy confirmed this result. The bandgap of the material was estimated to be about 1.72 eV using ultraviolet–visible spectroscopy. The antibacterial activity of nanopowder was investigated on two bacteria, Escherichia coli and Staphylococcus aureus. Each bacteria strain was cultured in its specific culture medium containing two concentrations (1% and 2%) of iron oxide nanopowder. The nanoparticles were first irradiated by two UV lamps at zero (control), 30 min, 60 min, and 120 min. Sampling and culturing were performed for all times, the UV lamps were then turned off, and sampling and culturing were repeated after 24 h. Each microorganism was cultured in the appropriate conditions, and after 24 h, the number of bacteria was counted. The results of this experiment for both bacteria showed that irradiation with UV rays as well as different concentrations of iron oxide nanoparticles reduced the number of bacteria and the concentration of 2% caused a further decrease in the number of bacteria. The best result was obtained by simultaneous application of the 2% nanoparticle concentration and UV irradiation.