1：Experimental Design and Method Selection:

The study employs a combination of chemical oxidative polymerization, sol–gel method, and calcination to fabricate CdS@void@SiO2 yolk–porous-shell nanospheres (YSNs). The design aims to create a protective porous SiO2 shell around CdS nanoparticles to enhance stability and protect organic carriers.

2：Sample Selection and Data Sources:

CdS nanoparticles are synthesized via solvent-thermal techniques. Various samples with different PPy layer thicknesses (1, 3, 5, 7 layers) are prepared to tune the void size. Dye removal and hydrogen evolution experiments use methylene blue (MB) and rhodamine B (RhB) as model pollutants.

3：List of Experimental Equipment and Materials:

Equipment includes field-emission scanning electron microscopy (FESEM, Zeiss Supra 55VP), transmission electron microscopy (TEM, Hitachi H7650), high-resolution TEM (HRTEM, JEOL JEM-2010), Fourier transform infrared spectroscopy (FTIR, Bruker Vector 22), X-ray photoelectron spectroscopy (XPS, Thermo Fisher K-Alpha), X-ray diffractometer (XRD, Bruker AXS D8), BET surface area analyzer (ASAP 2460 Micromeritics), UV–vis spectrophotometer (Shimadzu UV-3600), fluorescence spectrophotometer (Hitachi F-4500), electrochemical workstation (CHI 604E), ICP-OES (CCD), photochemical reactor (PuLin-01), and CO2 infrared gas analyzer (MH410D). Materials include cadmium acetate, acetone, DMSO, ferric nitrate, PEG, TEOS, ethanol, sublimed sulfur, RhB, MB, pyrrole, HCl, NMMO, cotton fabric, and nonwovens.

4：Experimental Procedures and Operational Workflow:

CdS nanoparticles are synthesized by solvent-thermal method. PPy layers are deposited on CdS via chemical oxidative polymerization. SiO2 shell is formed using sol–gel process with TEOS and PEG, followed by calcination to remove PPy and create voids. Photocatalytic performance is tested under visible light irradiation for dye removal and hydrogen evolution. Textile coating is done using dipping method with NMMO solution.

5：Data Analysis Methods:

Data analysis involves BET for surface area, XRD for crystal structure, XPS for elemental composition, FTIR for chemical bonds, UV–vis for light absorption, photoluminescence for emission spectra, electrochemical measurements for photocurrent, ICP-OES for Cd2+ concentration, and statistical analysis of dye removal efficiency and hydrogen evolution rates.