Effect of Alteration of Precipitating Agents Structural, Optical, and Antibacterial Properties of Y₂O₃ Nanoparticles

In present report, yttrium oxide (Y₂O₃) nanoparticles were successfully synthesized using different chemical precursors, such as acetic acid, oxalic acid, sodium carbonate and urea, via a controlled precipitation route. The crystalline structure and phase purity of the obtained samples were confirmed through X-ray diffraction (XRD), which revealed the formation of cubic Y₂O₃ with crystallite sizes in the nano-meter range. Moreover, the Fourier transform infrared spectroscopy (FTIR) confirmed the presence of characteristic Y–O stretching vibrations with exclusion of residual organic species. In morphological analysis, field emission scanning electron microscopy (FE-SEM) demonstrated well-dispersed nanoparticles with morphology and particle size strongly influenced by the choice of precursor. The optical characteristics and the optical band gap, estimated from UV–VIS absorption spectra, varied between 5.1–5.6 eV, showing precursor-dependent shifts linked to crystallinity and particle size. Raman spectroscopy further validated the cubic phase of Y₂O₃, with subtle peak shifts attributed to phonon confinement effects in nanoscale systems. However, the antibacterial performance of the synthesized Y₂O₃ were evaluated against Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative) and Pseudomonas aeruginosa (Gram-negative). All samples exhibited measurable antibacterial activity, with acetic acid-derived Y₂O₃ showing the highest inhibition zones (18 mm for S. aureus and 19 mm for E. coli ). Comparative analysis revealed that Gram-positive bacteria were more susceptible than Gram-negative strains, consistent with the protective role of the outer membrane in Gram-negative bacteria. Overall, the study highlights that the selection of precipitating agent or precursor significantly governs crystallinity, morphology, and surface reactivity of Y₂O₃ nanoparticles, which in turn directly influence their optical and antibacterial properties.