1：Experimental Design and Method Selection:

The synthesis involved using Bi(NO3)3 and melamine in 1 M HNO3 as precursors for the one-pot synthesis of Bi2O3/g-CN composites. The materials were characterized by SEM, TEM, XPS, and their photocatalytic activity was evaluated under visible light irradiation.

2：Sample Selection and Data Sources:

The loading in Bi2O3 was varied from 1.25 to 10 wt% to study its effect on photocatalytic activity.

3：25 to 10 wt% to study its effect on photocatalytic activity. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Materials included melamine (99%, Sigma), Bi(NO3)3.5H2O (> 99.99%, Sigma), and HNO3 (65%, Fisher Scientific). Equipment included SEM, TEM, XPS, UV–vis spectrometer, and photoluminescence spectrofluorimeter.

4：5H2O (> 99%, Sigma), and HNO3 (65%, Fisher Scientific). Equipment included SEM, TEM, XPS, UV–vis spectrometer, and photoluminescence spectrofluorimeter. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The synthesis involved dissolving melamine and Bi(NO3)3 in HNO3, drying the mixture, and then heating it at 500 °C for 2 h. Photocatalytic experiments were conducted under visible light irradiation using a 300 W Hg-Xe lamp.

5：Data Analysis Methods:

The photocatalytic activity was evaluated by measuring the degradation of RhB under visible light irradiation. Data were analyzed using UV–vis spectroscopy.