1：Experimental Design and Method Selection:

The β-In2S3-ZnO composite catalysts were synthesized using a low temperature co-precipitation method followed by low temperature reflux. The doctor blading technique was used to form thin films.

2：Sample Selection and Data Sources:

Weight percentages of β-In2S3 loaded into ZnO were varied (0,

3：5, 35, 70, 100 wt.%). Samples were characterized using XRD, UV-vis, TEM, SEM, and BET surface area analysis. List of Experimental Equipment and Materials:

Equipment includes PANalytical X'Pert PRO MPD XRD diffractometer, Shimazu UV-3101PC Diffused reflectance UV-vis Spectrophotophotometer, Hitachi S-4800 HR-TEM and SEM, Autosorb 1 MP Quantachrome analyzer. Materials include InCl

4：4H2O, thioacetamide, HClO4, NH4OH, glacial acetic acid, Triton X, DI water, glass slides. Experimental Procedures and Operational Workflow:

Synthesis involved dropwise addition of InCl

5：4H2O into thioacetamide, pH adjustment to 0, reflux at 95°C for 5 h, centrifugation, washing, drying. Film preparation involved grinding catalyst powder with additives, casting slurry, annealing at 350°C for 1 h. Photocatalytic tests used RhB solution, dark adsorption for 1 h, irradiation with 50 W Halogen lamp, sampling every 30 min, UV-vis analysis. Data Analysis Methods:

XRD for crystallinity, UV-vis for absorption and band gap calculation using Kubelka-Munk function, TEM/SEM for morphology, BET for surface area, photocatalytic degradation efficiency calculated from absorbance changes.