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

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 Fe 3 (HITP) 2 /bpm@Co (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) is reported through inserting bpm (4,4'-bipyrimidine) ligands and Co 2+ into the interlayers of 2D MOF Fe 3 (HITP) 2 . Compared to 2D Fe 3 (HITP) 2 (37.23 m 2  g -1 ), 3D Fe 3 (HITP) 2 /bpm@Co displays a huge improvement in the specific surface area (373.82 m 2  g -1 ). Furthermore, the combined experimental and density functional theory (DFT) theoretical calculations demonstrate the metallic behavior of Fe 3 (HITP) 2 /bpm@Co, which will benefit to the electrocatalytic activity of it. Impressively, Fe 3 (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 Fe 3 (HITP) 2 and comparable to commercial IrO 2 . DFT theoretical calculation reveals that the combined action of the Fe and Co sites in Fe 3 (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.