1：Experimental Design and Method Selection:

The study synthesized CuS/TiO2 composites via hydrothermal methods to combine UV-responsive TiO2 with narrow bandgap CuS for improved light absorption and photo-thermal conversion. Theoretical models focus on semiconductor photocatalysis and photo-thermal effects.

2：Sample Selection and Data Sources:

Samples included TiO2 nanosheets, CuS, and CuS/TiO2 composites with varying CuS ratios (e.g., 2%). Data were obtained from laboratory experiments using synthesized materials.

3：List of Experimental Equipment and Materials:

Equipment included Teflon autoclaves, high-speed centrifuge, X-ray diffractometer (Smart Lab, Rigaku), transmission electron microscope (TEM, JEOL JEM-2100F), X-ray photoelectron spectrometer (Thermo ESCALAB 250XI), UV-vis-NIR spectrophotometer (Shimadzu UV-3600), 300 W xenon lamp (PLS-SXE300C, Beijing Perfect light Technology), gas chromatography (GC9790II, Zhejiang Fuli Analytical Instrument), and Hiden HPR20 mass spectrometer. Materials included tetrabutyl titanate, hydrofluoric acid, thiourea, CuCl2·2H2O, ethanol, NaHCO3, distilled water.

4：Experimental Procedures and Operational Workflow:

TiO2 nanosheets were synthesized hydrothermally at 180°C for 24h. CuS/TiO2 composites were prepared by adding Cu and S precursors to TiO2 solution, hydrothermally treating at 160°C for 12h, followed by centrifugation, washing, and drying. Photocatalytic CO2 reduction involved dispersing catalyst on glass plate, evacuating reactor, injecting CO2, irradiating with xenon lamp, and analyzing gas products at intervals.

5：4h. CuS/TiO2 composites were prepared by adding Cu and S precursors to TiO2 solution, hydrothermally treating at 160°C for 12h, followed by centrifugation, washing, and drying. Photocatalytic CO2 reduction involved dispersing catalyst on glass plate, evacuating reactor, injecting CO2, irradiating with xenon lamp, and analyzing gas products at intervals. Data Analysis Methods:

5. Data Analysis Methods: Data were analyzed using XRD for phase identification, TEM for morphology, XPS for surface composition, UV-vis-NIR for light absorption, GC for product quantification, and in-situ FT-IR for mechanistic studies. Statistical analysis included comparison of CO yields and temperature measurements.