1：Experimental Design and Method Selection:

The study used a solvothermal method for synthesizing TiO2-graphene nanocomposites and refluxing for intercalation with tin porphyrin. Photocatalytic activity was assessed under visible light irradiation.

2：Sample Selection and Data Sources:

Methyl orange dye was used as the target pollutant. Samples included pure TiO2, TG composites with 1%, 3%, and 5% graphene, and TGSP (tin porphyrin-pillared TG).

3：List of Experimental Equipment and Materials:

Equipment included an autoclave, ultrasound irradiator, and filtration setup. Materials included graphite oxide, TiO2 nanoparticles, ethanol, H2O, pyridine, SnCl2.2H2O, DMF, and tert-butanol.

4：2H2O, DMF, and tert-butanol. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Graphite oxide was synthesized by Hummers method and exfoliated to graphene oxide. TG composites were prepared by solvothermal reaction at 120°C for 24h. TGSP was synthesized by refluxing TG (3%) with SnTCPP.Cl2 in DMF. Photocatalytic tests involved degrading methyl orange under visible light, with control experiments in absence of light or catalyst.

5：4h. TGSP was synthesized by refluxing TG (3%) with SnTCPP.Cl2 in DMF. Photocatalytic tests involved degrading methyl orange under visible light, with control experiments in absence of light or catalyst. Data Analysis Methods:

5. Data Analysis Methods: Photodegradation efficiency was monitored via absorption spectral changes. Mechanisms were investigated using oxygen-free conditions and hydroxyl radical scavengers.