Durable Pt-Decorated NiFe-LDH for High-Current-Density Electrocatalytic Water Splitting Under Alkaline Conditions

The development of durable and efficient catalysts capable of driving both hydrogen and oxygen evolution reactions is essential for advancing sustainable hydrogen production through overall water electrolysis. In this study, we developed a corrosion-mediated approach, where Ni ions originate from the self-corrosion of the nickel foam (NF) substrate, to construct Pt-modified NiFe layered double hydroxide (Pt-NiFeO_xH_y@NiFe-LDH) under ambient conditions. The obtained catalyst exhibits a hierarchical architecture with abundant defect sites, which favor the uniform distribution of Pt clusters and optimized electronic configuration. The Pt-NiFeO_xH_y@NiFe-LDH catalyst, constructed through the interaction between Pt sites and defective NiFe layered double hydroxide (NiFe-LDH), demonstrates remarkable hydrogen evolution reaction (HER) activity, delivering an overpotential as low as 29 mV at a current density of 10 mA·cm^-2 and exhibiting a small tafel slope of 34.23 mV·dec^-1 in 1 M KOH, together with excellent oxygen evolution reaction (OER) performance, requiring only 252 mV to reach 100 mA·cm^-2. Moreover, the catalyst demonstrates outstanding activity and durability in alkaline seawater, maintaining stable operation over long-term tests. The Pt-NiFeO_xH_y@NiFe-LDH electrode, when integrated into a two-electrode system, demonstrates operating voltages as low as 1.42 and 1.51 V for current densities of 10 and 100 mA·cm^-2, respectively, and retains outstanding stability under concentrated alkaline conditions (6 M KOH, 70 °C). Overall, this work establishes a scalable and economically viable pathway toward high-efficiency bifunctional electrocatalysts and deepens the understanding of Pt-LDH interfacial synergy in promoting water-splitting catalysis.