Green and cost-effective photocatalytic degradation of murexide dye with acid catalyst

This study investigates the degradation of Murexide dye, a significant environmental hazard, through organo-photocatalysis. Oxalic acid emerges as a highly efficient catalyst, stimulating further examination within a photoreactor box. These optimal conditions were confirmed by Response Surface Methodology as a statistical tool. The most efficient degradation of murexide dye was achieved at 50 ppm dye concentration, 15 ppm OA acid catalyst concentration, and 80 min reaction time (97.67%). Additionally, HPLC and GC–MS analyses were conducted to identify the major intermediate products of the degraded MX. GC–MS analysis revealed that the main product (Z)-5-((4-oxido-6-oxotetrahydropyrimidin-5(2H)-ylidene)amino)-2,6-dioxo-1,2,3,6-tetrahydropyrimidin- 4-olate m/z = 256, along with different amines (iminomethaniminium with m/z = 43, acetamide with m/z = 60)) was obtained at the end. Kinetic data revealed that the degradation was fitted by the Langmuir–Hinshelwood model. The mechanistic aspects of the study were carried out using density functional theory. Furthermore, these findings can be used to develop new technologies and contribute to the development of sustainable wastewater treatment systems as well.