Silver Nanoparticle-Decorated NiFe-MOFs as Highly Active Electrocatalysts for Overall Water Splitting

Abstract

Designing clean, stable, and efficient electrocatalysts is the key to achieving overall water splitting. The introduction of active metals or metal nanoparticles into metal–organic frameworks (MOFs) is a research strategy. In this work, silver nanoparticles (Ag NPs) loaded on NiFe-MOF can increase the surface area, active sites, and conductivity of the catalyst. Therefore, the electrocatalytic performances of Ag/NiFe-MOF exhibit higher activity for HER and OER in an alkaline medium, and the overpotential is also significantly lower than that when NiFe-MOF is used alone. When the current density is 10 mA cm^–2, the overpotential of the optimized Ag/NiFe-MOF-30 catalyst is 138 mV for HER and 173 mV for OER. In addition, when Ag/NiFe-MOF-30 is used as a bifunctional electrocatalyst, the overall water splitting can be achieved with 1.61 V at 10 mA cm^–2, and it demonstrates excellent stability of over 100 h at 100 mA cm^–2. This work provides an efficient approach for developing highly active MOF-based catalysts by loading coin metal nanoparticles for overall water splitting.