1：Experimental Design and Method Selection:

A two-step hydrothermal method was used to synthesize Zn2SnO4 QDs decorated Bi2WO6 nanocomposites. The design aimed to create a heterojunction to improve photocatalytic activity under visible light.

2：Sample Selection and Data Sources:

Pure Bi2WO6 and Zn2SnO4 QDs/Bi2WO6 composites with different Zn2SnO4 amounts (1%, 2%, 3%, 4%, 5%) were prepared. Acetone was used as the model gaseous contaminant.

3：List of Experimental Equipment and Materials:

Chemicals included ZnCl2, SnCl4·5H2O, NaOH, Bi(NO3)3·5H2O, Na2WO4·2H2O, CH3COOH, all analytical grade from Sinopharm Chemical Reagent Co., Ltd. Equipment: scanning electron microscope (JSM-5600LV, Oxford, UK), high transmission electron microscopy (JEOL JEM-2100), powder X-ray diffractometer (Bruker D8, Germany), UV–vis spectrophotometer (UV-2600, Shimadzu, Japan), FTIR spectroscopy (LabSolutions IR, Shimadzu, Japan), CHI660E electrochemistry workstation (Chenhua, Shanghai, China), gas chromatograph (Agilent 7890A, USA), 500 W Xe lamp with cutoff filter.

4：Experimental Procedures and Operational Workflow:

Synthesis involved hydrothermal reactions at 200°C. Photocatalytic tests were conducted in a quartz reactor with visible light irradiation, monitoring acetone degradation via gas chromatography. In-situ FTIR was used to identify intermediates.

5：Data Analysis Methods:

XRD for crystal structure, SEM/TEM for morphology, UV-Vis DRS for optical properties, PL and SPV for charge separation, photoelectrochemical measurements for current and impedance, kinetic analysis using Langmuir-Hinshelwood model.