Thienyl-Bridged Fused Porphyrin Tapes for Enhanced Heterogeneous Electrocatalytic Activity

Abstract

The development of highly conjugated metalloporphyrin assemblies is a crucial step to improve their catalytic activity for optimal energy conversion processes. Herein, di-thienyl substituted nickel(II) porphyrin is used to form a highly conjugated porphyrin structure. The resulting porphyrin-based conjugated polymer catalyst exhibited exceptional oxygen evolution reaction “OER” performances, featuring a low onset overpotential of 266 mV and high reaction kinetics (Tafel slope of 69.9 mV/dec) under alkaline pH conditions, achieving a current density of 4.5 mA/cm². The remarkable OER catalytic activity of porphyrin-based conjugated polymer catalyst is attributed to the enhancement of the conjugation, which occurs through a unique process involving direct fusion of the porphyrins followed by thienyl bridging of the fused porphyrin tapes, ultimately leading to the establishment of a highly cross-linked porphyrinic network.