Tetracycline-assisted photocatalytic H2O2 generation and concurrent in situ pollutant degradation via J-aggregated Perylene Diimide derivative

The use of active free radicals with strong oxidation ability generated by photocatalysis to degrade pollutants especially antibiotic is an economically effective method (Advanced Oxidation Process, AOP). In this study, a triazole-modified perylene diimide supramolecular organic photocatalyst (PDI-TA) was employed to facilitate the photocatalytic degradation of tetracycline hydrochloride (TCH). The incorporation of the triazole group not only enhances the self-assembly of PDI-TA molecules but also fosters hydrogen bonding interactions between PDI-TA and pollutant molecules. Under visible light irradiation, PDI-TA achieved a TCH degradation efficiency of 75 % within 40 min. Furthermore, it demonstrated the ability to continuously generate H 2 O 2 at a rate of 1400 μmol g −1 h −1 in an air atmosphere. Notably, during the degradation of resorcinol, the H 2 O 2 production rate increased to 2600 μmol g −1 h −1 . Superoxide radicals (·O 2 − ), hydroxyl radicals (·OH), and photogenerated holes (h + ) were identified as the primary reactive oxygen species (ROS) responsible for TCH degradation, with hydroxyl radicals being derived from hydrogen peroxide. In the presence of phenolic pollutants, the PDI-TA system exhibited dual functionality: pollutant molecules were adsorbed onto PDI-TA, facilitating electron transfer. During the degradation process, these pollutants effectively consumed photogenerated holes. Both mechanisms promote the separation of photogenerated charge carriers, thereby accelerating the overall degradation process. Additionally, according to literature reports, phenolic pollutants can supply protons, further enhancing H 2 O 2 production and thus expediting pollutant degradation. This synergistic effect has not been previously reported in PDI-based supramolecular photocatalysts, marking a significant advancement in the field. • A novel J-Aggregated PDI photocatalyst was synthesized by high-temperature solvent method. • Nitrogen-rich functional groups of PDI contribute to the adsorption of pollutants. • Phenolic-pollutants assisted H 2 O 2 generation and concurrent promotion of pollutants degradation by H 2 O 2 was found. • Pollutants accelerated photogenerated e−/h + separation. • Phenolic hydroxyl groups were key active sites for facilitating H 2 O 2 generation.