نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
In this study, chitosan/ZnO nanocomposite was synthesized via the co-precipitation method and characterized by FTIR, XRD, SEM, EDX, BET, and PL. A specific surface area of 38.2 m²/g, pore volume of 0.124 cm³/g, and pore diameter of 10.8 nm, along with a type IV isotherm, confirmed the mesoporous nature. The removal performance of methylene blue (MB) and malachite green (MG) was evaluated at a high concentration of 500 mg/L under UV and visible light irradiation, achieving 91–93% efficiency under optimal conditions. Kinetics revealed that the pseudo-first-order model was more suitable for three systems, while the pseudo-second-order model fitted MB-Vis better. Equilibrium data were consistent with the Langmuir model. Recycling over four cycles demonstrated stability above 80%. The decrease in PL intensity from 98 to 27 relative units indicated reduced electron-hole recombination and improved charge separation. Scavenger tests confirmed the dominant role of superoxide radicals under UV and the photosensitization mechanism under visible light. The novelty of this research lies in providing a quantitative framework to distinguish the adsorption contribution from photocatalysis, identifying active species under both irradiation spectra, and evaluating performance at concentrations close to real wastewater.
کلیدواژهها English
