Ni(OH)/NiFe-PBA heterostructure nanoarrays with a surface-reconstructed Cl repelling layer for efficient and stable seawater electrolysis.

A Ni(OH)/NiFe-PBA heterostructure nanoarray catalyst was designed as an efficient oxygen evolution reaction (OER) electrocatalyst for alkaline seawater electrolysis, achieving a current density of 10 mA cm at an overpotential of 292 mV. Notably, the Ni(OH)/NiFe-PBA catalyst undergoes reconstruction during the OER, generating NiOOH as the active site and Fe(CN) species as the Cl repelling layer, suppressing chloride oxidation and improving stability. This synergistic mechanism enhances catalytic stability, enabling sustainable operation for 1000 hours at 500 mA cm, offering a viable strategy for hydrogen production from seawater.