1：Experimental Design and Method Selection:

An impregnation process was used to prepare C–TiO2 ?lms by dipping glass substrates in a glucose-containing TiO2 sol, followed by drying and calcination at controlled temperatures (200-350°C). The photocatalytic activity was evaluated by degrading gaseous NOx under visible and UV light.

2：Sample Selection and Data Sources:

Glass substrates were cleaned and coated with C–TiO2 ?lms. Gaseous NOx was used as the pollutant, with concentrations measured using a NOx analyzer.

3：List of Experimental Equipment and Materials:

Equipment includes an ultrasonic cleaning machine, air oven, impregnation setup, calcination furnace, photocatalytic reactor with light sources (blue LED for visible light, black lamp for UV), NOx analyzer, X-ray diffractometer, SEM, TEM, UV-VIS spectrophotometer, XPS, electrochemical analyzer, and contact angle meter. Materials include STS-01 TiO2 sol, D-glucose, glass substrates, acetone, NaOH, DI water, nitrogen gas, air, nitric oxide gas, and NaCl solution for photochemistry analysis.

4：Experimental Procedures and Operational Workflow:

Substrates were cleaned, immersed in the glucose-TiO2 sol for 10 minutes, pulled out at constant speed, dried at 100°C under nitrogen, and calcined at specific temperatures. Photocatalytic tests involved exposing the ?lms to 1 ppm NO gas under light irradiation and measuring concentration changes over time.

5：Data Analysis Methods:

XRD data were analyzed using Scherrer's formula to calculate grain sizes. Photocatalytic ef?ciency was calculated based on NOx removal rates. UV-VIS spectra were analyzed using the Tauc equation to determine bandgaps. XPS data were ?tted to identify carbon species. Photocurrent densities were measured via linear sweep voltammetry.