1：Experimental Design and Method Selection:

The study utilized MoS2 nanosheets as a photoanode for the photoelectrochemical activation of sulfite to produce oxysulfur radicals. The methodology included the preparation of MoS2 nanosheets via liquid-exfoliation method and the fabrication of MoS2/TiO2/ITO electrodes.

2：Sample Selection and Data Sources:

Bulk MoS2 powder was used as the starting material for the preparation of MoS2 nanosheets. The concentration of ammonia nitrogen in wastewater was varied from

3：0 to 0 mg/L. List of Experimental Equipment and Materials:

Equipment included an ultrasonic probe processor, UV-Vis spectrophotometer, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Raman spectrometer, high resolution transmission electron microscope (HRTEM), X-ray photoelectron spectroscopy (XPS), Atomic Force Microscope (AFM), and an electrochemical workstation. Materials included MoS2 powder, ethanol/water mixture, Na2SO3, and other chemicals for electrode preparation and analysis.

4：Experimental Procedures and Operational Workflow:

The MoS2 nanosheets were prepared by sonication and centrifugation, followed by electrode fabrication and characterization. Photoelectrochemical tests were conducted under visible light irradiation with varying conditions such as pH, bias potential, and dissolved oxygen concentration.

5：Data Analysis Methods:

The degradation of ammonia was monitored spectrophotometrically, and the products were analyzed for nitrate and nitrite nitrogen. The kinetics of ammonia degradation were analyzed using pseudo first-order reaction kinetics.