Zeolite encapsulated Cu(II)-salen complexes for catalytic Rhodamine B degradation

Abstract

We successfully synthesized two copper complexes (CuL1 and CuL2) with N₄-tetradentate salen-ligands and encapsulated them within zeolite frameworks. Comprehensive characterization of both free and encapsulated complexes was performed using multiple analytical techniques. When employed as catalysts for H₂O₂-mediated Rhodamine B degradation, CuL2 demonstrated superior activity, which we attribute to the electropositive character of its imidazole moiety. Notably, encapsulation-induced modifications were observed in both the optical properties and catalytic performance of the complexes, arising from the constraint of the zeolite supercage structure. Under optimized conditions, the zeolite-encapsulated CuL1-Y achieved 85% degradation efficiency, comparable to its free complex counterpart. Furthermore, the CuL1-Y system exhibited excellent recyclability.