Modulating the hydrophilicity and conductivity of covalent organic frameworks for enhanced oxygen evolution reaction

Abstract

A series of multivariate fluorinated covalent organic frameworks (COF-Tfmbx, x = 0, 33, 50, 67, 100) are designed through strategic integration of Co²⁺ centers and fluorine-containing units to simultaneously enhance conductivity and hydrophilicity for superior oxygen evolution reaction (OER) performance. In particular, Co-COF-Tfmb₅₀ exhibits exceptional electrocatalytic oxygen evolution reaction (OER) performance, achieving a mere 362 mV overpotential at 10 mA cm⁻², a low Tafel slope of 53 mV dec⁻¹, and outstanding stability (93% current retention after 24 h), attributed to synergistic effects of: fluorine-enabled charge transfer, hydrophilic interface optimization and hierarchical pore architecture facilitating mass transport. These results demonstrate an effective approach to designing and constructing novel COF-based OER catalysts.