Ru-Doped NiFe Layered Double Hydroxide as a Highly Active Electrocatalyst for Oxygen Evolution Reaction

Improving the intrinsic catalytic activity of NiFe layered double hydroxide (LDH), which is a benchmark electrocatalyst for oxygen evolution reaction (OER), is a significant challenge. In the present study, we doped ruthenium ions into NiFe LDH (Ru-NiFe LDH) to accelerate the OER kinetics. Electrochemical measurements of NiFe LDH and Ru-NiFe LDH at similar mass loadings showed that Ru-NiFe LDH demonstrated a higher OER activity than that of NiFe LDH. Ru-NiFe LDH only requires an overpotential of 246 mV at 10 mA cm(-2) in alkaline media. This attributes to ruthenium doping primarily, which can promote the catalytic activity of Fe sites and boost the electronic interaction among the Ni, Fe, and Ru metals according to the theoretical calculations. Ru-NiFe LDH is stable during OER stability measurements, which was confirmed by structure and elemental analysis. These findings will provide a useful approach for promoting the intrinsic activity of multi-metallic (oxy) hydroxide electrocatalysts toward the OER.