1：Experimental Design and Method Selection:

The study involved synthesizing PANI@W18O49 composite via a facile solvent evaporation method to enhance photocatalytic activity. Theoretical models focused on the built-in junction between n-type W18O49 and p-type PANI for improved charge separation.

2：Sample Selection and Data Sources:

Samples included pure W18O49, PANI, and PANI@W18O49 composites with different weight ratios (1 wt%, 3 wt%, 7 wt%). Data were collected from photocatalytic experiments under various light sources.

3：List of Experimental Equipment and Materials:

Equipment included XRD (JEOLJDX 8030), Raman (Labram HR800), FTIR (Magna-IR 750), SEM (Zeiss Merlin), TEM (TecnaiG2F20), UV–vis DRS (Hitachi U4100), PL (FLS 980), ion chromatograph (ICS-1000, Dionex), UV–vis spectrophotometer (TU-1810), and light sources (300 W Xe lamp, 200 W mercury lamp, 200 W infrared lamp). Materials included WCl6, aniline, APS, THF, sodium nitrite, and organic acids.

4：Experimental Procedures and Operational Workflow:

Synthesis of W18O49 via solvothermal method, PANI via polymerization, and PANI@W18O49 via solvent evaporation. Photocatalytic tests involved stirring catalyst suspensions in nitrite solution under dark for adsorption equilibrium, followed by irradiation with light sources. Samples were periodically withdrawn, filtered, and analyzed for nitrite, nitrate, and ammonium concentrations.

5：Data Analysis Methods:

Data were analyzed using pseudo-first-order kinetics for reaction rates, and N2 selectivity was calculated based on concentration changes. Statistical analysis included comparison of different catalysts and conditions.