1：Experimental Design and Method Selection:

The study used the sol-gel process for synthesis, with structural analysis via X-ray diffraction (XRD), Rietveld refinement, Raman spectroscopy, scanning electron microscopy (SEM), and photoluminescence spectroscopy including excitation, emission, and lifetime measurements to correlate structural and photoluminescent properties.

2：Sample Selection and Data Sources:

TiO2 powders doped with Eu3+ at concentrations of 0.2, 3, and 7 mol% were synthesized, with heat treatments at 700, 750, 800, and 900 °C for 8 hours. Data were sourced from laboratory analyses of these synthesized samples.

3：2, 3, and 7 mol% were synthesized, with heat treatments at 700, 750, 800, and 900 °C for 8 hours. Data were sourced from laboratory analyses of these synthesized samples. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment includes XRD 6000 diffractometer (Shimadzu), Brucker SENTERRA Raman spectrometer, TSCPC/HORIBA spectrofluorimeter, and SEM. Materials include tetraethylorthotitanate (TEOT, Merck, 95%), europium oxide (Eu2O3, Estarm – 99.99%), anhydrous ethanol, propylene glycol, hydrochloric acid, and EDTA for standardization.

4：99%), anhydrous ethanol, propylene glycol, hydrochloric acid, and EDTA for standardization. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Synthesis involved mixing precursors, stirring, drying to form xerogels, grinding, and heat treatment. XRD was performed with CuKα radiation, Raman with 785 nm laser, photoluminescence with excitations at 394 nm and 464 nm, and lifetime measurements with a phosphorimeter. Data were collected at room temperature.

5：Data Analysis Methods:

XRD data were refined using the Rietveld method with GSAS software. Photoluminescence data were analyzed for emission intensities, lifetime decays fitted to exponential models, and asymmetry ratios calculated from band areas.