Green Synthesis of TiO<sub>2</sub> Nanoparticles Using Piper Longum Leaf Extract: Morphological, Optical and Antibacterial Characterization

In this study, Titanium dioxide nanoparticles (TiO 2 NPs) were synthesized using Piper longum leaf extract as both a capping and reducing agent through a green synthesis approach. The synthesized TiO 2 NPs were thoroughly characterized using multiple techniques: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Diffuse reflectance spectroscopy (UV-DRS), field emission scanning electron microscopy (FESEM), High-Resolution Transmission Electron Microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) analysis, and X-ray photoelectron spectroscopy (XPS). XRD analysis confirmed the anatase phase of TiO 2 with an average crystallite size of 57 nm. UV-DRS revealed a band gap of 3.39 eV, indicative of TiO 2 nanoparticle formation. FTIR spectroscopy identified biomolecules such as flavonoids, phenol compounds, and tannins around the nanoparticles. SEM images showed a variety of shapes, including hexagons, pentagons, triangles, and tetragons. EDX analysis confirmed the presence of titanium, carbon, and oxygen, verifying the purity of the TiO 2 nanoparticles. BET analysis determined a specific surface area of 59 m²/g. The antibacterial efficacy of the TiO 2 nanoparticles was assessed using the agar well diffusion method, demonstrating significant antibacterial activity against Pseudomonas aeruginosa, Streptococcus mutans, Staphylococcus aureus, and Klebsiella pneumoniae. Additionally, the photocatalytic degradation of methylene blue dye by the TiO 2 NPs achieved an efficiency of 96%.