Perylene diimides coated Fe-MOFs as acid-tolerant photo-Fenton catalyst for phenol removal

Abstract

Abstract Fe-based metal–organic frameworks (MOF) are used in photo-Fenton oxidation processes, but they are easily decomposed in wastewater resulting to deactivation. For reducing Fe-MOF deactivation, herein, we reported an effective strategy, that is, coating the surface of Fe-MOF by re-crystallization PDI (perylene-3,4,9,10-tetracarboxylic diimide), and formed encapsulated Fe-MOF@PDI photo-catalyst. The performance of the catalyst is correlated with the amount of the PDI\xa0layer for forming heterojunction of PDI/Fe-MOF in catalysts. As the load amount of PDI increasing from 3% to 6% and 9%, the Fe-MOF@6%PDI exhibits the better activity for phenol removal in 30\xa0min. Moreover, constructed Fe-MOF@PDI photo-catalysts show acid resistance increased because PDI covered is with stable H-type π-π stacking in acidic conditions, and protects the inside Fe-MOF from decomposing. A range of Fe-MOFs are encapsulated in re-crystallization PDI, and the photo-Fenton activity and stability of the Fe-MOFs is enhanced since heterojunction structure formed. This work provides a facile and simple strategy toward the preparation of acid-stable MOF-based composites for the application in acidic wastewater remediation.