Heterostructured Bimetallic MOF‐on‐MOF Architectures for Efficient Oxygen Evolution Reaction

Abstract Electron modulation presents a captivating approach to fabricate efficient electrocatalysts for the oxygen evolution reaction (OER), yet it remains a challenging undertaking. In this study, an effective strategy is proposed to regulate the electronic structure of metal–organic frameworks (MOFs) by the construction of MOF‐on‐MOF heterogeneous architectures. As a representative heterogeneous architectures, MOF‐74 on MOF‐274 hybrids are in situ prepared on 3D metal substrates (NiFe alloy foam (NFF)) via a two‐step self‐assembly method, resulting in MOF‐(74 + 274)@NFF. Through a combination of spectroscopic and theory calculation, the successful modulation of the electronic property of MOF‐(74 + 274)@NFF is unveiled. This modulation arises from the phase conjugation of the two MOFs and the synergistic effect of the multimetallic centers (Ni and Fe). Consequently, MOF‐(74 + 274)@NFF exhibits excellent OER activity, displaying ultralow overpotentials of 198 and 223 mV at a current density of 10 mA cm −2 in the 1.0 and 0.1 M KOH solutions, respectively. This work paves the way for manipulating the electronic structure of electrocatalysts to enhance their catalytic activity.