1：Experimental Design and Method Selection:

The study used an impregnation method to load NaOH, KOH, and CsOH nanoparticles onto commercial Fe2O3 to create hybrid photocatalysts. The photocatalytic activity was evaluated in a gas-phase static system for IPA degradation.

2：Sample Selection and Data Sources:

Commercial Fe2O3 (Hematite) with a BET surface area of 5.2 m2 g?1 was used. Alkaline hydroxides (NaOH, KOH, CsOH) were sourced from Wako corp. Samples were prepared with loading amounts of 0.05, 0.1, 0.4, and 1 wt%.

3：2 m2 g?1 was used. Alkaline hydroxides (NaOH, KOH, CsOH) were sourced from Wako corp. Samples were prepared with loading amounts of 05, 1, 4, and 1 wt%. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Equipment included a 300 W xenon arc lamp (ILC Technology, CERMAX LX-300) with a cutoff filter (L44, Hoya Optics) for visible light irradiation, a gas chromatograph (GC-14B, Shimadzu) with a flame ionization detector for analysis, a UV-visible spectrometer (UV-2500, Shimadzu), a field emission scanning electron microscope (FE-SEM, JEOL-JSM 6500F), and an X-ray diffractometer (XRD, X'pert Pro; PANalytical Co.). Materials included Fe2O3, NaOH, KOH, CsOH, distilled water, and isopropyl alcohol.

4：Experimental Procedures and Operational Workflow:

Alkaline hydroxide solutions were prepared and mixed with Fe2O3, dried on a hot plate, and heated at 450 °C for 2 hours. Photocatalytic tests were conducted in a 500 ml pyrex glass vessel with catalyst powder dispersed on a glass dish. The vessel was filled with artificial pure air, IPA was injected, and after dark adsorption for one hour, visible light irradiation was applied. Gaseous samples were extracted periodically and analyzed by GC.

5：Data Analysis Methods:

Data from GC analysis were used to quantify acetone and CO2 generation. Characterization data from XRD, UV-Vis spectroscopy, and SEM were analyzed to assess structural, optical, and morphological properties.