Dual-Functional Interface Molecular Engineering of Conductive MOF Nanoarrays for Oxygen Evolution Reaction

Drawing conceptual inspiration from the inorganic–organic hybrid architecture of natural Photosystem II, this work presents a dual-functional interface molecular engineering strategy. A Ni(TCNQ)2-FcDA nanoarrays (NAs) composite catalysts were constructed by anchoring ferrocene dicarboxylic acid (FcDA), featuring both proton-relay and redox activities, onto conductive Ni(TCNQ)2 nanoarrays (Ni(TCNQ)2 NAs). Structural characterizations indicate that carboxyl groups in FcDA participate in interfacial proton transport, while Ni–Fe coupling synergistically modulates the electronic structure of the active Ni centers. Theoretical calculations indicate that this interfacial engineering induces a significant downshift in the Ni 3d orbital d-band center, effectively lowering the energy barrier for the OH to O conversion step. Consequently, the catalyst achieves a current density of 10 mA cm–2 at an overpotential of only 226 mV in 1.0 mol L–1 KOH, with a low Tafel slope of 30.4 mV dec–1 and stability exceeding 24 h. Kinetic analysis further reveals a concerted proton-coupled electron transfer (PCET) mechanism. This work presents a strategy for synergistically addressing mass transport bottlenecks and electronic structure mismatches in conductive MOFs via dual-functional molecular interface engineering.