This paper reports an investigation into the effect of a number of operating factors on the removal of Ponceau 4R (Acid Red 18) from an aqueous solution through photodegradation in the presence of nitrogen. N2 was doped in situ on Cu-TiO2. The photocatalyst was UV/TiO2-Cu applied in suspension to the solution to achieve a larger catalyst surface area. The optimal values of photocatalyst dose, dye concentration, and pH were found to be 0.8mg L.1, 20mg L.1, and 7, respectively. The nitrogen gas was found to have a highly positive role in degradation. The aqueous solution was characterized for its COD. Photocatalyst efficiency was evaluated using XRD, SEM, and EPR techniques. The post-treatment product was characterized using FT-IR, HPLC, and GC-MS studies, intermediate compounds were detected, and a pathway was proposed for the degradation of the dye.