Synthesis, Characterization and Antibacterial Activity of TiO₂ and Cu-Doped TiO₂ Nanoparticles Using Chemical and Green Synthesis Methods

Abstract

Titanium dioxide (TiO₂) nanoparticles and copper-doped TiO₂ nanomaterials were synthesized and investigated for their structural, morphological, and antibacterial properties. TiO₂ nanoparticles were prepared using both a chemical sol-gel route and a green synthesis approach employing Aloe vera leaf extract. Titanium tetra isopropoxide (TTIP) was used as the precursor, while Aloe vera extract acted as a natural reducing and stabilizing agent in the green synthesis process. The synthesized materials were subjected to structural and morphological characterization using X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analysis confirmed the formation of crystalline anatase TiO₂, with the characteristic diffraction peak at 2θ ≈ 25.27° corresponding to the (101) plane. The average crystallite size of the pristine TiO₂ sample was approximately 41.9 nm. Cu doping resulted in slight changes in diffraction peak intensity, broadening, and peak position while retaining the anatase TiO₂ structure. SEM analysis revealed a porous surface morphology, with pore sizes ranging approximately from 0.5 to 3 μm. The antibacterial activity of the synthesized nanoparticles was evaluated against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus using the agar disc diffusion method. Pure TiO₂ exhibited inhibition zones of 12 mm and 18 mm against E. coli and S. aureus, respectively, whereas 25% Cu-doped TiO₂ showed significantly enhanced inhibition zones of 24 mm and 31 mm, respectively. These results demonstrate that Cu incorporation substantially improves the antibacterial performance of TiO₂ nanoparticles. The synthesized TiO₂ and Cu-doped TiO₂ nanomaterials therefore show promising potential for antibacterial applications in biomedical, surface-coating, and related antimicrobial technologies.