1：Experimental Design and Method Selection:

The study uses green chemistry with lemongrass extract for synthesis, followed by wet impregnation for doping. Characterization includes SEM-EDS, TEM, CL, PL, UV-Vis DRS, Raman spectroscopy, and XRD to analyze properties.

2：Sample Selection and Data Sources:

Samples include pure TiO2 and Fe-doped TiO2 with molar ratios of

3：05, 075, and 1 Fe3+ :

Ti. Data are derived from laboratory measurements using specified equipment.

4：List of Experimental Equipment and Materials:

Equipment includes SEM (Hitachi S2500), TEM (JEM 2100HT JEOL), UV-Vis spectrophotometer (Thermo Scientific EVOLUTION-600), XRD (Panalytical X'Pert Pro Alpha1), Raman spectrometer (HORIBA Jobin Yvon LabRAM HR800), CL analyzer (Hamamatsu PMA-12), PL setup with He-Cd laser, Soxhlet extractor, ultrasound processor (WiseClean WUC-A06H), centrifuge (universal centrifuge PLC-012E), muffle furnace (Thermo Scientific FB1415M), GC-MS (Agilent Technologies 6890 Series Plus). Materials include lemongrass leaves, titanium(IV) isopropoxide, iron(III) chloride hexahydrate, ethanol, distilled water.

5：Experimental Procedures and Operational Workflow:

Lemongrass extract is prepared via Soxhlet extraction. TiO2 nanoparticles are synthesized by adding titanium isopropoxide to the extract under ultrasound, washed, and calcined. Fe doping is done by wet impregnation. Characterization involves sample preparation and analysis using the listed techniques.

6：Data Analysis Methods:

Data are analyzed using Debye-Scherrer's equation for crystal size, Tauc plot for band gap, EDS for elemental composition, and spectral analysis for luminescence and absorption.