Green synthesis of titanium dioxide nanoparticles using green tea (Camellia sinensis) extract: Characteristics and applications

Abstract

Titanium dioxide (TiO₂) nanoparticles were successfully synthesized using titanium isopropoxide as a substrate and green tea extract as a reducing agent in the synthesis process. The structural characteristics of TiO₂ were analyzed using advanced techniques such as scanning electron microscope, energy dispersive X-ray, X-ray diffraction analysis, and N₂ adsorption/desorption isotherm. TiO₂ nanoparticles with a crystal size of 21.04 nm were calculated using the Debye–Scherer equation, indicating a dominant anatase structure. The synthesized TiO₂ nanomaterial exhibited a spherical shape and formed aggregates, with a surface area of 18.33 m²·g⁻¹. Additionally, the antibacterial activity of TiO₂ nanoparticles was evaluated using the disk diffusion method, and the minimum inhibitory concentration against gram-positive bacteria Staphylococcus aureus and gram-negative bacteria Escherichia coli was found to be 7.5 and 11.25 mg·mL⁻¹, respectively. In addition, the photocatalytic degradation of TiO₂ activates and generates free radicals such as ˙OH and

, which have strong oxidizing abilities. These radicals break down the molecular structure and remove approximately 76% of tetracycline antibiotics. Incorporating TiO₂ in facial wash formulations significantly enhances the sun protection factor. Green synthesis of TiO₂ nanoparticles using Camellia sinensis extract is not only suitable for sustainable activities but also becomes a versatile material with great application potential in fields such as cosmetics, medicine, and environmental remediation.