Fabrication of perylene imide-modified NH2-UiO-66 for enhanced visible-light photocatalytic degradation of tetracycline

A series of perylene imide-modified NH2-UiO-66 (PIU) photocatalysts, used for tetracycline-hydrochloride (TC center dot HCl) photocatalytic degradation, have been successfully prepared via the amidation reaction between 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) and amino groups on NH2-UiO-66 (UiO). PTCDA converted into perylene imide (PI) on the surface of UiO after amidation. Such covalent linkage provides a platform for PI as an electron acceptor to transfer electrons from UiO, leading to the improved separation efficiency of electron-hole pairs. In the TC center dot HCl photocatalytic degradation, the performance of PIU was enhanced significantly compared with that of pristine UiO. The apparent rate constant and the total removal rate on the optimized PIU (7PIU) are about 73 and 4 times higher than pristine UiO. After three reuses, 7PIU remains a good photocatalytic activity. Furthermore, the main reactive species and the electron transfer process are discussed. This study might provide a new strategy for the design of effective MOF-based photocatalysts and demonstrates the potential of imide-modified MOFs for pollution removal.