1：Experimental Design and Method Selection:

The sol-gel method was used for synthesis, with citric acid as the complexing agent, to achieve good homogeneity, pure phase, and low sintering temperature. The process involved optimizing pH and CA/M ratio to study their effects on structure and luminescence.

2：Sample Selection and Data Sources:

Samples were prepared based on the formula Li1+x-yNb1-x-3yTix+4yO3 with x=

3：1, y=1, doped with 3 wt.% Eu3+. Starting materials included LiNO3(AR), Nb2O5(4N), Ti(C4H9O)4(AR), Eu2O3(5N), HNO3(AR), citric acid (5%), ethylene glycol, and ammonia solution. List of Experimental Equipment and Materials:

Equipment included an electric furnace for calcination at 450°C for 4h and 850°C for 6h, X-ray Diffractometer (D/Max-2550, Rigaku) for XRD analysis, field-emission scanning electron microscope (FE-SEM, Zeiss Ultra 55) for morphology observation, and spectrometer (F-4500, Hitachi) for excitation and emission spectra measurements. Materials were of analytical or high purity grades.

4：Experimental Procedures and Operational Workflow:

Reagents were weighed stoichiometrically; Nb2O5 was dissolved in HF at 80°C for 12h; Eu2O3 was dissolved in HNO3; LiNO3 and Ti(C4H9O)4 were dissolved in water and alcohol, respectively; solutions were mixed; citric acid and ethylene glycol were added; pH was adjusted with ammonia; mixture was stirred at 80°C for 8h; xerogel was dried at 130°C for 48h; precursor powder was calcined.

5：Data Analysis Methods:

XRD spectra were analyzed over 2θ range of 20 to 80°; SEM images were used for morphology; excitation and emission spectra were measured at room temperature; intensity ratios (R = I(5D0→7F2)/I(5D0→7F1)) were calculated; comparisons were made with commercial Y2O3:Eu3+ phosphor.