1：Experimental Design and Method Selection:

The sonochemical method was used for synthesis to achieve nanoparticles with high purity and surface area. Characterization techniques included XRD, FT-IR, Raman, TGA, XPS, SEM, TEM, EDS, UV-Vis DRS, PL, and HPLC for analysis.

2：Sample Selection and Data Sources:

Precursors were TiO2 (P25) and Magnesium nitrate hexahydrate. Congo red dye was used as the model pollutant.

3：List of Experimental Equipment and Materials:

Equipment included sonochemical apparatus, calcination furnace, XRD, FT-IR spectrometer, Raman spectrometer, TGA, XPS, SEM, TEM, EDS, UV-Vis spectrophotometer, PL spectrometer, HPLC, and pH meter. Materials included TiO2 (P25), Magnesium nitrate hexahydrate, Congo red, and scavengers like EDTA, IPA, and Benzoquinone.

4：Experimental Procedures and Operational Workflow:

Synthesis involved sonication of precursors, calcination at 700°C for 2 hours. Photocatalytic tests were conducted by irradiating dye solutions with visible light, varying catalyst amount, dye concentration, and pH. Scavenger studies were performed to identify active species.

5：Data Analysis Methods:

Band gap calculated using UV-Vis DRS data, crystallite size using Debye-Scherrer formula, and degradation efficiency monitored via UV-Vis absorption.