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

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-tetra-carboxylic diimide), and formed encapsulated Fe-MOF@PDI photo-catalyst. The performance of the catalyst is correlated with the amount of the PDI layer 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 min. Moreover, constructed Fe-MOF@PDI photo-catalysts show acid resistance increased because PDI covered is with stable H-type ?-? 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.

Automated summary

This study reports an effective strategy of coating Fe-MOF surface with re-crystallization PDI to enhance stability under acidic conditions and improve catalytic activity through the formation of heterojunction structure. The Fe-MOF@PDI catalysts show increased acid resistance and better activity for phenol removal, making them suitable for acidic wastewater treatment applications.