Photocatalytic degradation of tetracycline antibiotics using three-dimensional network structure perylene diimide supramolecular organic photocatalyst under visible-light irradiation

Abstract The occurrence of antibiotics in the ambient environment has raised serious concerns. In this work, the kinetics and mechanism of photocatalytic degradation tetracycline (TC) was investigated using three-dimensional network structure perylene diimide supramolecular organic photocatalyst (3D-PDI). Under visible-light irradiation, 3D-PDI exhibited excellent degradation performance and stability for several tetracycline-based antibiotics (e.g., tetracycline; chlortetracycline; oxytetracycline.). The adsorption and degradation rate of TC by 3D-PDI were 8.21 and 12.7 times higher than that of bulk-PDI. The enhanced adsorption and degradation performance of TC by 3D-PDI were mainly due to the larger specific surface area and π-electron conjugation of 3D network supramolecular system. Superoxide radical ( O2−), hydrogen peroxide (H2O2) and hole (h+) the main reactive species (RSs) for TC degradation. Under the attack of photocatalytic RSs, TC undergoes hydroxylation, demethylation, aromatization, and ring-opening processes, and finally complete mineralization into CO2 and H2O. These results revealed that perylene diimide supramolecular photocatalyst may be efficiently applied for the remediation of tetracycline contaminated natural waters.