1：Experimental Design and Method Selection:

A hydrothermal method was used to synthesize TiO2/RGO composites by controlling the oxidation degree and content of GO to tailor TiO2 properties and enhance photocatalytic activity.

2：Sample Selection and Data Sources:

Flake graphite (325 mesh) was used as the starting material for GO synthesis; all chemicals were from Sinopharm Chemical Reagent.

3：List of Experimental Equipment and Materials:

Equipment included Teflon reactors, autoclaves, ultrasonic cleaning machine, FE-SEM (Phillips XL-30 FEG/NEW), TEM (Phillips Model CM200), nitrogen adsorption apparatus (ASAP 2020, USA), XRD (BRUKER DADVANCE Diffractometer), Raman spectrometer (Horiba Jobin Yvon XploRA), UV-vis spectrophotometer (SHIMADZU UV-3600 Plus), fluorescence spectrophotometer (SHIMADZU RF5301), XPS (PHI5300, USA), mercury analyzer (VM-3000, Mercury Instruments, Germany). Materials included graphite, KMnO4, H2SO4, H3PO4, H2O2, Ti(SO4)2, ethanol, deionized water.

4：Experimental Procedures and Operational Workflow:

GO was synthesized by pressurized oxidation with varying reaction times (3, 5, 7, 9 hours). TiO2/RGO composites were prepared hydrothermally at 150°C for 24 hours. Photocatalytic activity was evaluated using a bench-scale system with LED and UV light sources, measuring Hg0 removal efficiency.

5：Data Analysis Methods:

Data were analyzed using Scherrer's formula for crystal size, BET equation for surface area, BJH method for pore properties, and various spectroscopic techniques for structural and chemical analysis.