Kaolin-supported Ag-Cu/g-C3N4 nanocomposite for efficient photocatalytic removal of methylene blue dye from aqueous solution

Sunlight-driven photocatalytic degradation is a cost-effective and eco-friendly technology for removing organic pollutants from contaminated water. In our study, we use cheap and locally available kaolin as support for the fabrication of the 3-Ag-Cu/g-C 3 N 4 nanocomposite via a simple chemical reduction method. The as-synthesized nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS), and all these techniques confirm the formation of the Ag-Cu/g-C 3 N 4 /kaolin nanocomposite. The photocatalytic activity of the nanocomposite was examined by analyzing its degradation efficiency for methylene blue (MB) dye under sunlight irradiation. The influence of different experimental parameters such as catalyst dosage, initial dye concentration, and solution pH on the photocatalytic degradation of MB was investigated. The 3-Ag–Cu/g-C₃N₄/kaolin NC exhibited a degradation efficiency of 98.95% under the optimized conditions after 120 min of sunlight irradiation. Scavenger experiments showed that the degradation of MB on 3-Ag–Cu/g-C₃N₄/kaolin NC was mainly controlled by the synergistic effects of photogenerated holes (h⁺) and superoxide radicals (•O₂⁻), with hydroxyl radicals (•OH) playing a relatively small role. Clinical trial number: Not applicable