Reconstructing the Electric Double Layer via Ni-HAB MOF-Derived Conductive Ligands: Modulating Debye Length and Reducing the Deprotonation Energy Barrier for the Oxygen Evolution Reaction

Achieving efficient conversion of intermediate species is a core scientific challenge in the oxygen evolution reaction (OER). Conventional research primarily focuses on modulating the activity of metal sites while neglecting the inherent relationship between an electric double layer (EDL) structure and solid–liquid interfaces. Herein, we propose a π-conjugated ligand-induced EDL reconstruction strategy for efficient and safe OER through barrier-tailored deprotonation. The structural reconstruction of the two-dimensional conductive hexaaminophenyl-based metal–organic framework (Ni-HAB) is achieved via depolarization, and the dissociated π-conjugated HAB ligands leverage electrostatic interactions to significantly enhance the EDL charge density, drive directional enrichment of charged species, and extend the Debye length by 89%, thereby restructuring the EDL to accelerate deprotonation of *OH and *OOH intermediates and improve conversion of intermediate species. The overpotential of NiOOH derived from Ni-HAB decreased by 37.5% (reduction from 442 mV to 268 mV)@10 mA cm–2 with a Tafel slope of 72 mV dec–1 and maintained >99% stability after 200 h of operation at 100 mA cm–2. This work reveals the dual role of dissociated conductive MOF ligands in concurrently regulating the EDL architecture and reaction pathways, establishing a new paradigm for interface capacitance-driven catalyst design.