A Kinetic Control Strategy for One-Pot Synthesis of Efficient Bimetallic Metal-Organic Framework/Layered Double Hydroxide Heterojunction Oxygen Evolution Electrocatalysts

Heterojunction materials are promising candidates for oxygen evolution reaction (OER) electrocatalysts to break the linear scaling relationship and lower the reaction barrier. However, the application of heterojunction materials is always hindered by the complicated multistep synthetic procedures which bring cost, complexity, and reproducibility issues. Herein, a strategy of kinetic controlled synthesis is developed to achieve the one-pot formation of bimetallic metal-organic framework (MOF)/layered double hydroxide (LDH) heterojunction electrodes as highly efficient OER electrocatalysts. The heterojunction electrodes present hierarchical structures with highly porous NiFe-LDH nanosheet networks vertically grown on the surface of NiFe-MOF-74 microprisms, promoting fast mass transport and high exposure of active sites. The strong interactions at the MOF/LDH heterojunction interfaces contribute to the outstanding OER activity surpassing the state-of-art RuO2 OER catalysts. The MOF/LDH heterojunction electrode exhibits an ultralow overpotential of only 159.7 mV to reach the current density of 10 mA cm(-2), and yields large current densities at small overpotential (100 mA cm(-2) at 230.2 mV and 1000 mA cm(-2) at 284.3 mV) with long-term durability. This study presents an innovative approach to construct heterojunction materials with simple one-step synthesis, offering a promising pathway for high-efficiency electrocatalyst development.