By: Mohammad, Saeed, Hassan, Samaei, Hashemi, Mohammad Reza, Isfahan, Yousefinejad
Industrial wastewater contamination from azo dyes is a serious environmental and public health concern that requires efficient and sustainable treatment technologies. In this study, the synthesis, comprehensive characterization, and enhanced photocatalytic performance of Ag/N/TiO2 for the degradation of Acid Orange 25 in the presence of persulfate under visible and solar light were investigated. Structural analyses (XRD, FTIR, FESEM-EDX, DRS) confirmed uniform synthesis, nitrogen incorporation, effective photodeposition of silver, and spherical particles ( SO4–· > ·OH. The kinetic results exhibited pseudo-first-order behavior and were consistent with the Langmuir–Hinshelwood model within the concentration range of 20–80 mg L−1. The quadratic model provided the best fit to the experimental data, and Sobol sensitivity analysis ranked dye concentration, reaction time, pH, photocatalyst dosage, and persulfate concentration as the most influential parameters, with the strongest interaction observed between pH and dye concentration. Monte Carlo simulation confirmed the robustness of the optimized model under 5% uncertainty. These findings demonstrate the potential of Ag/N/TiO2 in the presence of persulfate for efficient azo dye degradation under visible-light and sunlight irradiation.


