1：Experimental Design and Method Selection:

The synthesis of Pb-doped SrTiO3 nanocrystals was accomplished by sol–gel method. The reaction mixtures were dissolved in methyl alcohol, stirred, and then heated to form a gel, which was further calcined to facilitate crystallization.

2：Sample Selection and Data Sources:

Titanium (IV) isopropoxide, strontium nitrate, lead (II) nitrate, ethylene glycol, and citric acid were used as raw materials.

3：List of Experimental Equipment and Materials:

X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectroscopy (DRS), 300 W Xe-arc lamp, and UV-vis spectrophotometer were used.

4：Experimental Procedures and Operational Workflow:

The photocatalytic reactions were performed with a 300 W Xe-arc lamp and a 410 nm cut-off filter. The photocatalytic activity was evaluated by the decomposition of Rhodamine B under visible light irradiation.

5：Data Analysis Methods:

The photocatalytic oxidation of organic pollutants follows Langmuir-Hinshelwood kinetics, where the rate is proportional to the coverage.