Improving the Antibacterial Properties of SnO2/Mn3O4 Hybrid Thin Film Synthesized by Spray Pyrolysis Method

The current study used the spray pyrolysis method to prepare tin oxide, manganese oxide, and SnO2/Mn3O4 hybrid bilayer thin films. The primary solutions for the deposition process were produced utilizing the sol-gel method. X-ray diffraction, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, and photoluminescence spectroscopy were used to analyze the grown films. XRD spectrum of SnO2, Mn3O4, and SnO2/Mn3O4 hybrid bilayer thin film shows that SnO2 thin film has a polycrystalline structure with a tetragonal cassiterite phase, Mn3O4 thin film shows a lower crystallinity degree due to the powdery nature of its surface, and XRD pattern of SnO2/Mn3O4 hybrid thin film has a polycrystalline structure. From the FESEM, the surface morphology of SnO2 thin film is crack-free and regular with incessant grain distribution. FESEM micrographs of the synthesized Mn3O4 thin film and the perfectly spherical grains of Mn3O4 are uniform and entirely separate, with an average size of less than 50 nm. FESSEM micrographs of SnO2/Mn3O4 hybrid thin film exhibit an uneven and porous polycrystalline structure with polyhedral granulation. The film's antibacterial properties were evaluated for standard gram-negative bacteria (GNB) and gram-positive bacteria (GPB), namely Staphylococcus aureus and Escherichia coli. According to the results, the hybrid bilayers have demonstrated better antibacterial properties than tin oxide and manganese oxide monolayers. These findings ascertain the role the hybrid thin film nanocomposites play in the biomedical field's potential applications.