1：Experimental Design and Method Selection:

The study employed a co-precipitation method for synthesizing the GO-ZrO2 nanocomposite, chosen for its simplicity and effectiveness in creating homogeneous dispersions. Characterization techniques included XRD, FTIR, FE-SEM, EDS, TEM, TGA, PL, UV-DRS, and BET analysis to assess structural, morphological, and optical properties. Photocatalytic activity was evaluated under visible light irradiation using a tungsten lamp.

2：Sample Selection and Data Sources:

Samples included synthesized GO-ZrO2 nanocomposite, pure ZrO2, and GO. Dye solutions of rhodamine B (30 mg/L) and methylene blue (100 mg/L) were used as model pollutants, selected based on their common occurrence in industrial wastewater.

3：List of Experimental Equipment and Materials:

Equipment: XRD (Model—AXS D8 Advance Bruker, Germany), SEM (Model—JEOL 6380A), TEM (Model—Joel/JEM 2100), UV-Vis spectrophotometer (Cary 5000 and UV-1800, Shimadzu), BET analyzer (Micromeritics ASAP 2020 V

4：04H), PL spectrofluorometer (JASCO FP-8200), TGA (TG-DTA-7200 Hitachi), FTIR spectrometer (IR-Affinity-1, Shimadzu). Materials:

Graphite powder (Sigma-Aldrich), sulfuric acid, potassium permanganate, hydrogen peroxide, hydrochloric acid, potassium hydroxide, zirconyl chloride octahydrate (Merck), ethanol, dyes (rhodamine B and methylene blue).

5：Experimental Procedures and Operational Workflow:

GO was synthesized via modified Hummers method. For GO-ZrO2, GO was dispersed in water, zirconium oxychloride added, pH adjusted with KOH, precipitate washed and dried, then calcined. Photocatalytic tests involved dispersing catalyst in dye solution, stirring in dark for adsorption equilibrium, irradiating with visible light, sampling at intervals, centrifuging, and measuring concentration with UV-Vis spectrophotometer.

6：Data Analysis Methods:

Photocatalytic efficiency calculated using degradation percentage formula. Kinetics analyzed with pseudo-first-order model. Statistical analysis not explicitly mentioned, but data from characterizations and degradation tests were compared.