Sol-gel synthesized undoped and Zr/Ce-doped TiO ₂ nanoparticles: Characterization, stability and its potential antibacterial performance

This study synthesized nano-sized titanium oxide (TiO 2 NPs), zirconium-doped titanium oxide (Zr@TiO 2 ), and cerium-doped titanium oxide (Ce@TiO 2 ) NPs utilizing sol-gel method. The synthesized nanoparticles were analyzed utilizing UV-DRS, XRD, Micro-Raman spectroscopy, FTIR, FESEM-EDAX, DLS, and zeta potential examination. Moreover, these nanoparticles were assessed for their antibacterial effectiveness using the agar well diffusion technique. XRD analysis showed that all nanoparticles were crystalline, with average crystalline diameters for TiO 2 , Zr@TiO 2 , and Ce@TiO 2 NPs are 15.05, 14.15, and 14.00 nm. FTIR confirmed all functional groups and Micro-Raman spectroscopy validated the bond formation in the synthesized materials. FESEM analysis revealed that pure TiO 2 displayed rod and irregular shaped particles with clusters. Whereas, the both Zr@TiO 2 and Ce@TiO 2 samples exhibited rod, spherical and irregular shaped particles with more agglomeration than undoped TiO 2 particles, with lengths of 395 nm, 539 nm, and 500 nm, and diameters of 28.20 nm, 52.62 nm, and 44.75 nm. The UV-DRS results indicated the reduction in their direct energy bandgaps from 2.91 eV for TiO 2 to 2.20 eV for Zr@TiO 2 and 2.55 eV for Ce@TiO 2 sample. Zeta potential analysis revealed that all the synthesized nanoparticles have good stability. The synthesized Ce@TiO 2 sample show exceptional zones of inhibition (17 and 15 mm) against the S. aureus and E. coli bacteria, making them a promising research material for wound treatment, antibacterial coatings on metal implants, medical devices and surfaces.