Tailoring the structural and non-linear optical properties of TiO2 nanoparticles via solvent-directed green synthesis

Abstract The development of materials with tunable structural and optical properties stands at the forefront of contemporary scientific research, given their broad applicability. In this study, we report the solvent-directed green synthesis of titanium dioxide nanoparticles (TiO 2 NPs) using Nyctanthes arbor-tristis (Night Jasmine) leaf extract as an eco-friendly reducing and capping agent. Synthesis was conducted employing both deionized (DI) water and ethanol as solvents to investigate their influence on the resulting nanoparticle properties. Comprehensive characterization using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), UV-Vis spectroscopy, photoluminescence (PL), Fourier Transform Infrared (FTIR) spectroscopy, and Raman spectroscopy provided deep insight into structural, morphological, chemical, and optical variations imparted by solvent selection. FESEM analysis revealed solvent-dependent differences in nanoparticle size and morphology, while XRD patterns confirmed crystalline structures with solvent-induced changes in crystallinity and phase distribution. Optical analyses (UV-Vis, PL, and Raman) demonstrated notable shifts in band gap energy and emission behavior, attributable to the solvent medium. The non-linear optical (NLO) properties, evaluated by Z-scan technique, further underscored the effect of solvent choice on TiO 2 NP functionality. This study highlights solvent-mediated modulation of TiO 2 NP characteristics through a sustainable green synthesis approach, offering promising avenues for photocatalytic and environmental remediation applications.