Hierarchical NiFe LDH/N-doped Co/nickel foam as highly active oxygen evolution reaction electrode for anion exchange membrane water electrolysis

Abstract

Anion exchange membrane water electrolyzers (AEMWEs) are emerging as a promising technology due to the high performance and low cost. However, the development of highly active and stable non-precious metal-based catalysts for the anodic oxygen evolution reaction (OER) remains a great challenge. In this study, we present a top-down construction strategy for anode design, resulting in a hierarchical NiFe layered double hydroxide (LDH)/N-doped Co/nickel foam (NF) electrode synthesized via a hydrothermal-gas phase nitridation–electrodeposition method. This electrode features NiFe LDH nanoplates grown on N-doped Co nanowires supported by nickel foam substrates. The NiFe LDH/N-doped Co/NF electrode demonstrates exceptional performance, achieving a current density of 100 mA·cm−2 at a low overpotential of 262 mV with minimal attenuation of just 7 mV after 100 h of operation. When assembled into an AEMWE, the system requires only 1.63 V to achieve a current density of 1 A·cm−2, surpassing the performance of most reported catalysts. The N-doped Co nanowires are shown to enhance both activity and stability by increasing the electrode’s surface area and reinforcing the catalyst–support interaction.