Ag-Zn bimetallic metal-organic frameworks (AgxZn1-x-MOFs) were grown on NiFe alloy foam (NFF) via a one-step hydrothermal route. The optimized Ag10Zn90-MOF/NFF requires overpotentials of only 220, 369 and 439 mV at 10, 1000 and 2000 mA cm-2, respectively, with stable operation for 120 h. During the oxygen evolution reaction (OER), the catalyst undergoes in situ reconstruction and transforms into an amorphous Ag/Zn oxyhydroxide phase (R-Ag10Zn90-MOF), as confirmed by XRD, XPS and TEM. Moderate Ag doping creates highly dispersed Ag+ sites and enhances Zn-O-Ag electronic coupling, thereby narrowing the bandgap to 0.189 eV and reducing the RDS energy barrier to 1.66 eV. The reconstructed phase exhibits lower overpotential and Tafel slopes, highlighting the important role of electrochemical restructuring in promoting OER activity. This study provides a composition-tuning strategy for activating Zn-MOFs via Ag doping to enable industrial-scale water splitting.
Liu et al. (Mon,) studied this question.