Enhancing OER Activity Through Water Treatment‐Induced Surface Reconstruction of Metal Surfaces

This research introduces a simple and effective method to enhance oxygen evolution reaction (OER) performance through surface reconstruction of metal substrates via hydration. A water treatment technique is employed to form a nanometer-thick hydroxide layer on Ni foam, which significantly improved OER activity compared to pristine Ni. To further explore catalyst performance on hydrated substrates, NiFe layered double hydroxide (LDH) is deposited, resulting in NiFe LDH@hydrated Ni foam achieving superior performance and exceptional stability, maintaining 1 A cm^-2 for 1000 h. In contrast, NiFe LDH@pristine Ni foam showed rapid degradation. Interestingly, while the hydrated hydroxide layer demonstrated remarkable OER activity, it is ineffective for hydrogen evolution reaction (HER). Density functional theory (DFT) calculations revealed the differing roles of hydroxides in OER and HER, providing insights into their electrochemical pathways. These findings highlight that simple hydration enhances the activity and long-term stability of LDH catalysts, addressing a key limitation in their practical use. This study demonstrates a promising and scalable strategy for improving OER performance and catalyst durability, offering valuable insights into the role of surface hydroxides in electrode reactions for energy applications.