Multifunctional, Novel Zinc-Pyrrole Polymeric MOF as Free Standing, Binder Free Supercapacitor Electrode and Photocatalyst for Organic Pollutant Degradation

Abstract

We developed a novel metal-organic framework (MOF) that incorporates a polymeric chain comprising a transition metal and a conducting polymer. It differs from traditional MOFs that rely on rigid organic linkers. Zinc ion was trapped between two pyrrole rings to form a stable complex, which was polymerized, resulting in a polymeric chain-based MOF (ZP-MOF); the conducting polymer served as a ligand. Because of its innovative structure, ZP-MOF functioned as a freestanding, binder-free electrode and exhibited a remarkable specific capacitance of 232.44 F g^–1 at a current density of 1 A g^–1, energy density of 26 Wh kg^–1, and power density of 1807 W kg^–1. The ZP-MOF delivered outstanding electrochemical performance and demonstrated exceptional cyclic stability, retaining 84% of its initial capacitance after over 5000 charge-discharge cycles at 10 A g^–1. The ZP-MOF also showed excellent potential in environmental applications such as degrading dyes, as 50 mg of it removed 98.52% of methylene blue dye from an aqueous solution (50 mL) within 40 min, even at high dye concentrations of 50 mg/L. These findings highlight the dual functionality of the as-developed ZP-MOF as an efficient energy storage material and a promising agent for dye wastewater treatment, underscoring its potential for diverse practical applications and setting new standards for MOF design.