1：Experimental Design and Method Selection:

The study utilized a hydrothermal method to fabricate silica-carbon quantum dots (Si-CQDs) from rice husk, with variations in temperature and pH to investigate their influence on the properties of Si-CQDs.

2：Sample Selection and Data Sources:

Rice husk was used as the natural carbon precursor, obtained from Jabatan Pertanian Negeri Perak, Malaysia.

3：List of Experimental Equipment and Materials:

Equipment included a high-resolution transmission electron microscope (HRTEM), X-ray diffractometer (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), UV-Vis spectrophotometer, and PL spectrometer. Materials included rice husk, nitrogen gas, nitric acid, sodium hydroxide, sulfuric acid, hydrochloric acid, and methylene blue.

4：Experimental Procedures and Operational Workflow:

Rice husk was converted into ash through pyrolysis, then oxidized and hydrothermally treated under varying conditions of temperature and pH. The resulting Si-CQDs were characterized and evaluated for their photocatalytic performance in methylene blue degradation.

5：Data Analysis Methods:

The properties of Si-CQDs were analyzed using HRTEM, XPS, Raman spectroscopy, and UV-Vis spectroscopy. The photocatalytic performance was evaluated by measuring the decolorization rate of methylene blue under visible light irradiation.