A doubly interpenetrated perylene diimide-based zirconium metal-organic framework for selective oxidation of sulfides powered by blue light

Abstract

Perylene diimide (PDI) with its unique photoactive properties can be employed as an effective building block for synthesizing vigorous metal-organic frameworks (MOFs) and photocatalytic performance can be anticipated. Specifically, we introduce the fabrication of a zirconium-based MOF, Zr-PDI-Me, which is deliberately constructed using PDI units via a solvothermal process. The resulting Zr-PDI-Me exhibits a double interpenetrated topological structure and boasts a considerable specific surface area of up to 634 m2/g. Furthermore, its photoelectric response is satisfactory as evidenced by electrochemical characterizations. Consequently, Zr-PDI-Me has served as a photocatalyst to selectively oxidize sulfides, demonstrating its excellent versatility. Importantly, it retains initial catalytic activity even after 5 cycles. Studies on the mechanism revealed that both superoxide radicals (O₂^•-) and singlet oxygen (¹O₂) promote the selective oxidation process to produce sulfoxides over Zr-PDI-Me. This work underscores the potential of incorporating photoresponsive organic functional groups into MOFs to create photoactive heterogeneous catalysts.