Formation of NiFe-MOF nanosheets on Fe foam to achieve advanced electrocatalytic oxygen evolution.

2D bimetal metal organic frameworks (MOFs) are recognized as one of the most promising electrocatalysts for the oxygen evolution reaction (OER). Herein, a facile approach was proposed to construct NiFe-MOF nanosheets on Fe foam (FF). As a self-supporting electrode, the NiFe-MOF/FF electrode shows impressive electrocatalytic OER performance. Specifically, it exhibits an ultra-low overpotential of 216 mV to reach a current density of 50 mA cm -2 , and outstanding stability (beyond 50 h at 200 mA cm -2 ). The excellent performances of NiFe-MOF/FF arise from the highly exposed active centers, the excellent conductivity, and the synergy effect between Ni and Fe. This research provides a promising strategy for the synthesis of multi-metal MOFs as high-efficiency electrocatalysts.