1：Experimental Design and Method Selection:

The sol-gel combustion method was used for synthesis. The morphology was studied and characterized by X-ray diffraction, field-emission scanning electron microscopy, and Brunauer-Emmetl-Teller method at 77 K.

2：Sample Selection and Data Sources:

Freshly precursor was used for the synthesis. The samples were prepared with 10% and 20% CeO2 on SiO2 base.

3：List of Experimental Equipment and Materials:

Equipment included a magnetic stirrer with heating IRE (Italy), drying oven M400 (Germany), furnace S 4800 (USA), UV-Vis 1800 Shimadzu (Japan), and U.V power supplies (USA). Materials included Ce(NO3)4 (Merck), HNO3 (Merck), PVA (Merck), methyl orange solution (MO) standard 1 g/l (1000 ppm), and distilled water.

4：Experimental Procedures and Operational Workflow:

PVA was dissolved in distilled water at 80°C, Ce(NO3)4 solution was added with a molar ratio Ce/PVA = 1/3 at pH 1. The mixture was stirred for 2 hours, then SiO2 powder was added with CeO2/(CeO2+SiO2) weight percentages of 10% and 20%. The system was stirred for another 2 hours, dried at 120°C for 4 hours, and calcined at 300°C for 2 hours.

5：The mixture was stirred for 2 hours, then SiO2 powder was added with CeO2/(CeO2+SiO2) weight percentages of 10% and 20%. The system was stirred for another 2 hours, dried at 120°C for 4 hours, and calcined at 300°C for 2 hours. Data Analysis Methods:

5. Data Analysis Methods: The photocatalytic capacity was evaluated by the degradation efficiency of methyl orange under visible light, measured by UV-Vis spectroscopy at λ = 464 nm.