1：Experimental Design and Method Selection:

The study used a modified nanocasting technique to duplicate the surface structure of Xanthosoma sagittifolium leaves onto polyimide films, followed by ion-exchange and thermal treatment to immobilize cuprous oxide nanoparticles.

2：Sample Selection and Data Sources:

Fresh leaves of Xanthosoma sagittifolium were used as templates; polyimide films were synthesized from PMDA and ODA monomers.

3：List of Experimental Equipment and Materials:

Materials included PMDA, ODA, DMAc, PDMS kit (SYLGARD 184), ethanol, copper(II) acetate, potassium hydroxide. Equipment included SEM (JEOL JSM-7401F or JSM-7100F), XPS (ULVAC-PHI PHI5000 VersaProbe), FTIR (Nicolet Protege-460), UV-vis spectrophotometer (Jasco V-650), TGA (TGA-Q500), BET surface area analyzer (Micromeritics ASAP2020), goniometer (DSA10-MK2), gas chromatograph (YL Instruments YL6500).

4：0). Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Steps involved preparing PDMS negative templates, casting PAA solutions, thermal imidization, surface hydrolysis with KOH, ion-exchange with copper acetate, thermal treatment, and characterization. Photocatalytic activity was measured in a batch reactor under LED illumination.

5：Data Analysis Methods:

Data were analyzed using SEM, XPS, FTIR, UV-vis, TGA, BET, contact angle measurements, and gas chromatography with PDHID.