NiFe LDH Hollow Nanocages Confined Ru Single Atoms for Remarkable Oxygen Evolution Reaction

Electrocatalysts with a hollow nanocage structure and single atoms (SAs) incorporated into layered double hydroxide (LDH) are highly significant for enhancing the efficiency of electrochemical water splitting. In this study, a highly efficient and robust electrocatalyst for the oxygen evolution reaction (OER) is successfully fabricated by confining Ru SAs within a hollow nanocage made of NiFe LDH. An etching and co-precipitation method is used for making the NiFe LDH hollow nanocages and integrating the Ru atoms to produce Ru-SAC/NiFe LDH. The nanocage architecture increases the surface area available for interaction and enhances the interface between the catalyst and electrolyte. The robust synergistic electronic contact between the Ru and NiFe LDH led to the exceptional OER performance with the low overpotential of 196 mV at 10 mA cm^‒2 and a Tafel slope of 40 mV dec⁻¹. Additionally, the catalyst revealed long-term stability, 120 h at 10 mA cm^‒2. Density functional theory (DFT) calculations show that Ru SAs increased OER activity because they interacted more strongly with OER intermediates and caused positive changes in Gibbs free energy. The goal of this research is to develop a novel approach for designing and fabricating advanced single-atomic materials intended for use in renewable energy applications.