1：Experimental Design and Method Selection:

The study used the successive adsorption and reaction (SILAR) method to immobilize BiOI nanosheets on cotton fabric treated with NaOH and urea for micro-dissolution. This method was chosen for its ability to uniformly deposit nanosheets at room temperature.

2：Sample Selection and Data Sources:

Cotton knitted fabric (150 g/m2) was obtained from Lu Thai Textile Co., LTD. Reagents including potassium iodide (KI), bismuth nitrate pentahydrate (Bi(NO3)3·5H2O), sodium hydroxide (NaOH), and urea were analytical grade from Sinopharm Chemical Reagent Co., Ltd.

3：List of Experimental Equipment and Materials:

Equipment included SEM (TM-1000, Hitachi), FESEM (S-4800, Hitachi), XRD (Rigaku D/max-2500PC), UV-Vis DRS (Lambda 35, PerkinElmer), Raman spectrometer (Thermo Fisher DXR2xi), TGA (DSC204FI), XPS (Thermo ESCALAB 250), UV transmittance tester (UV-1000F), contact angle analyzer (DSA30, Kruss), and a 500 W Xe lamp with UV cut-off filter (Shanghai Bilon instruments Ltd.). Materials included cotton fabric, chemicals for treatment and synthesis.

4：Experimental Procedures and Operational Workflow:

Cotton fabric was treated with urea/NaOH solution at -10°C for micro-dissolution, washed, and dried. BiOI nanosheets were immobilized via SILAR cycles (0 to 20 cycles) at room temperature, involving adsorption of Bi3? ions, rinsing, reaction with I? ions, and washing. Samples were characterized using SEM, XRD, UV-Vis DRS, Raman, TGA, XPS. Photocatalytic tests involved degrading RhB under visible light, UV shielding was measured, and hydrophobicity was assessed via contact angle measurements.

5：Data Analysis Methods:

Data were analyzed using UV-Vis spectrophotometry for RhB concentration, calculations for UPF and transmittance, and kinetic analysis for photodegradation rates. Statistical methods included standard deviations for contact angles.