1：Experimental Design and Method Selection:

The study used a hydrothermal method to synthesize RGO/SnO2/TiO2 composites with varying graphene content, comparing them to pure TiO2. Theoretical models include heterojunction structures for improved charge separation.

2：Theoretical models include heterojunction structures for improved charge separation. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Samples were prepared using GO from natural graphite via Hummers method, with SnCl4·5H2O and TiCl4 as precursors. Different composites (RST-A to RST-D) were made based on GO content.

3：List of Experimental Equipment and Materials:

Equipment includes autoclaves, centrifuges, drying ovens, tube furnace, TEM (JEOL JEM-2100), FTIR (Nicolet 460), XRD (SHIMADZU XRD-6000), UV–vis spectrophotometer (SHIMADZU UV-3600), electrochemical workstation (CHI660D), Xe lamp, Pt foil, SCE, and NaCl solution. Materials include GO, SnCl4·5H2O, NaOH, TiCl4, distilled water, Nafion solution.

4：Experimental Procedures and Operational Workflow:

GO was dispersed and sonicated; SnO2 was deposited on GO hydrothermally; TiO2 was added hydrothermally; composites were calcined. Electrodes were prepared by dipping dispersion on 304SS. Electrochemical measurements involved photocurrent, OCP, Tafel, and EIS in 3.5% NaCl with light on/off cycles.

5：5% NaCl with light on/off cycles. Data Analysis Methods:

5. Data Analysis Methods: Data were analyzed using equivalent circuit models for EIS, Tafel extrapolation for corrosion parameters, and UV–vis for band gap calculations.