1：Experimental Design and Method Selection:

A facile solvothermal method was used to synthesize ZnS–TiO2/RGO nanocomposites with different Ti4+ sources (P25 and TBOT). The method involved ultrasonic vibration, magnetic stirring, and heating in an autoclave.

2：Sample Selection and Data Sources:

Materials included zinc acetate, sodium sulfide, tetrabutyl titanate, methylene blue, ethylene glycol, absolute ethanol, graphene oxide solution, and TiO2 powder (P25). Deionized water was used for washing.

3：5). Deionized water was used for washing. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment included a Teflon-lined stainless steel autoclave, ultrasonic vibrator, magnetic stirrer, vacuum oven, X-ray diffractometer (D/max 2400), transmission electron microscope (F20), Raman spectrometer (Finder Vista), PL spectrometer (Finder Vista), UV-vis spectrometer (homemade), and xenon lamp (500 W). Materials were analytical grade reagents.

4：Experimental Procedures and Operational Workflow:

For ZTR-P25, dissolve Zn(Ac)2·2H2O and GO in ethylene glycol, add Na2S·9H2O and TiO2 powder, sonicate and stir, heat in autoclave at 180°C for 10 h, filter, wash, and dry. For ZTR-TBOT, similar steps but with absolute ethanol and TBOT. Photocatalytic tests involved stirring catalyst and MB solution in dark for 30 min, irradiating with xenon lamp, sampling at intervals, and measuring concentration via UV-vis spectroscopy.

5：Data Analysis Methods:

XRD for crystal phases, TEM for morphology, Raman and PL for chemical structures, UV-vis for absorption. Photocatalytic degradation rates calculated using pseudo-first-order kinetics equation -ln(Ct/C0) = kt.