1：Experimental Design and Method Selection:

The study involved synthesizing g-C3N4/Cu2O composites via a chemical precipitation method to form heterostructures, aiming to enhance photocatalytic efficiency by improving charge carrier separation. Theoretical models included band gap analysis and heterojunction mechanisms.

2：Sample Selection and Data Sources:

Samples included pure g-C3N4, Cu2O, and g-C3N4/Cu2O composites with varying Cu2O percentages (e.g., 9%, 45%, 56%). Data sources involved laboratory-synthesized materials and standard microbial cultures (E. coli and F. graminearum).

3：List of Experimental Equipment and Materials:

Equipment: D8 advance X-ray diffractometer (Bruker Corporation), Nicolet 5700 spectroscope, JSM-7001F FESEM (JEOL), JEM-2100 TEM (JEOL), ESCALAB250 XPS spectrometer, Hitachi U-3900H UV-DRS spectrometer, F-7000 fluorescence spectrometer (Hitachi), JEOL-JES-FA200 ESR spectrometer, 300 W xenon lamp with 400 nm cutoff filter, FZ-A optical radiometer, UV-vis spectrophotometer (Hitachi U-3900H). Materials: Urea, Cu(CH3COO)2·H2O, absolute ethanol, glucose, NaOH, tetracycline, E. coli, F. graminearum, agar medium, PBS buffer, scavengers (isopropanol, TEMPOL, sodium oxalate), DMPO.

4：Experimental Procedures and Operational Workflow:

g-C3N4 synthesized by thermal polycondensation of urea at 550°C; g-C3N4/Cu2O composites prepared by dispersing g-C3N4 in Cu(CH3COO)2 solution, adding glucose and NaOH at 60°C, then washing and drying. Characterization via XRD, FTIR, XPS, FESEM, TEM, UV-DRS, PL, and ESR. Photocatalytic tests: TC degradation in aqueous solution under visible light; microbial inactivation by irradiating E. coli and F. graminearum suspensions, sampling at intervals, plating on agar, and counting colonies. Trapping experiments with scavengers to identify active species.

5：Data Analysis Methods:

Data analyzed using first-order kinetics for TC degradation, colony counting for microbial inactivation, and spectral analysis (XRD, FTIR, XPS, etc.) for material properties. Statistical methods included triplicate experiments and average calculations.