1：Experimental Design and Method Selection:

The study employed a hydrothermal method to prepare 2D-2D TiO2 nanosheet/layered WS2 heterojunctions. The rationale was to combine the advantages of composite materials, nanomaterials, and interfaces to enhance photocatalytic activity.

2：Sample Selection and Data Sources:

Anatase TiO2 nanosheets with exposed (001) and (101) facets were prepared by a facile hydrothermal process. Layered WS2 was synthesized under the same conditions without adding TiO2 nanosheets.

3：List of Experimental Equipment and Materials:

Equipment included a Bruker AXS D8 Focus X-ray diffractometer, PerkinElmer PHI 1600 ESCA X-ray photoelectron spectroscope, Hitachi S-4800 SEM, JEM-2100F TEM, Renishaw InVia Raman spectrometer, NOVA-2000 volumetric gas sorption instrument, Shimadzu UV-2550 spectrophotometer, Fluorolog3 spectrofluorometer, and Bruker Daltonics micrOTOF-QII HPLC-MS/MS.

4：Experimental Procedures and Operational Workflow:

The synthesis involved dissolving sodium tungstate in deionized water, adjusting the pH, adding L-cysteine and TiO2 nanosheets, and reacting in a Teflon-lined stainless steel autoclave at 200 °C for 24 h. The products were collected, washed, and dried.

5：Data Analysis Methods:

The structure and morphology were characterized by XRD, XPS, SEM, TEM, Raman spectroscopy, BET surface area measurements, UV-Vis DRS, PL spectra, and HPLC-MS/MS.