Document Type : Regular Article

Authors

• Shatha Sh. Batros
• Mohammed H. Ali
• Ali J. Addie

Center of Advanced Materials, Materials Research Directorate, Ministry of Science and Technology – Iraq

Abstract

Tin oxide (SnO₂) nanoparticles were synthesized via a facile chemical precipitation route using tin chloride (SnCl₂•2H₂O) as precursor and ammonia as precipitant. The as-synthesized nanoparticles were subjected to post-calcination at 300°C, 400°C and 500°C and thoroughly characterized by advanced techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy. XRD patterns revealed the formation of tetragonal SnO₂ crystalline phase with average crystallite sizes of 11.9 nm, 13.9 nm and 17.2 nm for the samples calcined at 300°C, 400°C and 500°C respectively. SEM micrographs demonstrated agglomerated and irregular morphology of the calcined SnO₂ nanoparticles. FTIR spectra confirmed the presence of characteristic Sn-O and O-Sn-O vibrational modes in the calcined SnO₂ samples. The antibacterial activity of the synthesized nanoparticles was evaluated against model Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial strains by standard zone of inhibition assays. Remarkably, the SnO₂ nanoparticles exhibited excellent antibacterial activity due to their high specific surface area. A systematic increase in the inhibition zone diameter was observed with decrease in crystallite size of SnO₂ for both bacterial strains, suggesting an inverse relationship between crystallite size and antibacterial behavior. The present work demonstrates a simple, eco-friendly synthesis of antibacterial SnO₂ nanoparticles with controlled crystallite size by tuning the calcination temperature.

Keywords

• Tin oxide nanoparticles
• Antibacterial activity
• Chemical Precipitation
• Crystallite size control

Main Subjects

• Materials Science