Development of new ruthenium complex-based photocatalysts for the degradation of Remazol Red Ultra RGB

The contamination of aquatic environments by persistent synthetic dyes constitutes a significant environmental problem, with Remazol Red Ultra RGB standing out due to its high chemical stability and wide industrial application. In this work, ruthenium-based complexes were developed and evaluated as photocatalysts for the degradation of this dye in aqueous medium. The complexes were characterized by UV-Vis and infrared spectroscopy, cyclic voltammetry, and theoretical studies based on DFT and TD-DFT. In the photocatalytic assays, the materials showed high degradation rates, with emphasis on the NAT60 complex, which promoted 100% dye removal within 60 minutes of irradiation, evidenced by the decrease in the absorption band at 514 nm. The other complexes showed efficiencies higher than 70% within the same time interval. In order to evaluate the effect of a high surface area matrix, the catalyst was supported on mesoporous silica of the SBA-15 type, forming the NAT60/SBA-15 system, which maintained an efficiency of 85.25%, demonstrating high photocatalytic activity. The results confirm the potential of ruthenium complexes, both in molecular and supported forms, as promising photocatalysts for advanced oxidative processes applied to the sustainable treatment of dye-containing effluents.