1：Experimental Design and Method Selection:

The study aimed to synthesize KBiO3/g-C3N4 composites via microwave irradiation to enhance photocatalytic hydrogen production. The microwave method was chosen for its ability to facilitate homogeneous dispersion and binding without altering the crystal structure of the materials.

2：Sample Selection and Data Sources:

KBiO3 was synthesized by chemical substitution using KOH and NaBiO3, and g-C3N4 was synthesized by polycondensation of melamine. Composites were prepared with varying weight ratios of KBiO3 (5-90% wt).

3：List of Experimental Equipment and Materials:

Equipment included a Mars-6 microwave oven, XRD (Bruker Advanced X-ray Solutions D8), SEM (FEI Nova 200 NanoSEM), FTIR, N2 physisorption analyzer (BELSORP Mini-II), UV-Vis NIR spectrophotometer (Cary 500), batch-type reactor, high-pressure Hg pen-lamp (254 nm), and gas chromatography (Shimadzu GC-2014). Materials included KOH, NaBiO3, melamine, distilled water, and deionized water.

4：4). Materials included KOH, NaBiO3, melamine, distilled water, and deionized water. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: KBiO3 synthesis involved stirring KOH and NaBiO3 at 120°C for 2h, washing to pH=7, and drying at 100°C for 8h. g-C3N4 synthesis involved heating melamine at 500°C for 4h. Composites were prepared by mixing powders with water in a Teflon vessel, irradiating in microwave at 100W for 30min, drying at 80°C, and heating at 180°C for 2h. Characterization included XRD, FTIR, SEM, EDS-Mapping, N2 physisorption, and DRS. Photocatalytic tests involved dispersing 50mg catalyst in 200mL deionized water, purging with N2, irradiating with Hg lamp, and monitoring H2 evolution by GC every 30min for 3h.

5：8h. g-C3N4 synthesis involved heating melamine at 500°C for 4h. Composites were prepared by mixing powders with water in a Teflon vessel, irradiating in microwave at 100W for 30min, drying at 80°C, and heating at 180°C for 2h. Characterization included XRD, FTIR, SEM, EDS-Mapping, N2 physisorption, and DRS. Photocatalytic tests involved dispersing 50mg catalyst in 200mL deionized water, purging with N2, irradiating with Hg lamp, and monitoring H2 evolution by GC every 30min for 3h. Data Analysis Methods:

5. Data Analysis Methods: XRD patterns were analyzed for crystalline phases, FTIR for functional groups, SEM for morphology, EDS for element distribution, N2 physisorption for surface area, DRS for optical properties using Tauc plot for band gap calculation, and GC for hydrogen quantification.