1：Experimental Design and Method Selection:

The study involved preparing MoS2/g-C3N4 heterojunction composites via a two-step method including hydrothermal synthesis of MoS2 nano-spheres and calcination with melamine to form g-C3N4 coating. Theoretical calculations using DFT were combined with experiments to understand charge transfer mechanisms.

2：Sample Selection and Data Sources:

Samples included pure MoS2, pure g-C3N4, physically mixed MoS2/g-C3N4-P, and heterojunction MoS2/g-C3N4-H with different mass ratios. Chemicals were analytical grade from specified suppliers.

3：List of Experimental Equipment and Materials:

Equipment included XRD diffractometer, FTIR spectrometer, FE-SEM, TEM, XPS spectrometer, UV-Vis spectrophotometer, fluorescence spectrophotometer, electrochemical workstation, TOC analyzer. Materials included ammonium molybdate, thiourea, PVP, melamine, potassium dichromate, sodium oxalate, P-benzoquinone, isopropyl alcohol, Rhodamine B, silver nitrate.

4：Experimental Procedures and Operational Workflow:

MoS2 nano-spheres were synthesized hydrothermally, then coated with melamine, ultrasonically dispersed, stirred, centrifuged, dried, and calcined. Characterization involved XRD, FTIR, SEM, TEM, XPS, UV-Vis, PL, EIS, TOC tests. Photocatalytic measurements were done under simulated sunlight using LED, with degradation of RhB and reduction of Cr6+ monitored by UV-Vis spectrophotometry.

5：Data Analysis Methods:

Data analysis included fitting XRD and XPS peaks, calculating band gaps using Tauc plots, determining kinetic constants using first-order reaction models, and using scavengers to identify active species in photocatalytic processes.