In this work, titanium dioxide nanoparticles (TiO₂ NPs) were green-synthesized using jasmine (Jasminum sambac) flower extracts as the medium with different solvent variation concentrations. The green synthesis was carried out using titanium isopropoxide (TTIP) as a precursor via the sol-gel method. The obtained TiO₂ NPs were characterized using infrared spectroscopy (FTIR), ultraviolet spectroscopy (UV-DRS), X-ray diffraction (XRD), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FESEM/EDX), Raman spectroscopy, and high-resolution transmission electron microscopy/selected area diffraction (HRTEM/SAED). The characterization revealed that the green-synthesized TiO₂ NPs possess a pure tetragonal anatase phase, which belongs to the space group I41/amd. Dye-sensitized solar cell devices were further fabricated using the obtained TiO₂ NPs and sensitized with the commercial dye N719 and a kesumba (Bixa orellana) seed extract as an alternative, inexpensive, yet sustainable natural dye. The highest efficiency of 2.52% was obtained from TiO₂ NPs sensitized using commercial dye N719 and synthesized using jasmine flower extract containing 30% acetylacetone, followed by one containing 50% acetylacetone, which is higher than that of commercial TiO₂ (0.80%). The same materials sensitized using kesumba seed extract resulted in efficiency of 0.22%, 0.08%, and 1.22%, respectively. These findings offer insight and pave the way for more novel, environmentally friendly methods for developing green-synthesizing nanomaterials and natural dye derivatives, ultimately contributing to a sustainable future. © The Author(s) 2025.