A Conductive 3D Dual‐Metal π‐d Conjugated Metal–Organic Framework Fe₃(HITP)₂/bpm@Co for Highly Efficient Oxygen Evolution Reaction

Abstract Although 2D π‐d conjugated metal–organic frameworks (MOFs) exhibit high in‐plane conductivity, the closely stacked layers result in low specific surface area and difficulty in mass transfer and diffusion. Hence, a conductive 3D MOF Fe₃(HITP)₂/bpm@Co (HITP = 2,3,6,7,10,11‐hexaiminotriphenylene) is reported through inserting bpm (4,4′‐bipyrimidine) ligands and Co²⁺ into the interlayers of 2D MOF Fe₃(HITP)₂. Compared to 2D Fe₃(HITP)₂ (37.23 m² g⁻¹), 3D Fe₃(HITP)₂/bpm@Co displays a huge improvement in the specific surface area (373.82 m² g⁻¹). Furthermore, the combined experimental and density functional theory (DFT) theoretical calculations demonstrate the metallic behavior of Fe₃(HITP)₂/bpm@Co, which will benefit to the electrocatalytic activity of it. Impressively, Fe₃(HITP)₂/bpm@Co exhibits prominent and stable oxygen evolution reaction (OER) performance (an overpotential of 299 mV vs RHE at a current density of 10 mA cm⁻² and a Tafel slope of 37.14 mV dec⁻¹), which is superior to 2D Fe₃(HITP)₂ and comparable to commercial IrO₂. DFT theoretical calculation reveals that the combined action of the Fe and Co sites in Fe₃(HITP)₂/bpm@Co is responsible for the enhanced electrocatalytic activity. This work provides an alternative approach to develop conductive 3D MOFs as efficient electrocatalysts.