A dealloyed bulk FeNi pattern with exposed highly active facets for cost-effective oxygen evolution

Porous materials are attractive substrates for oxygen evolution reaction (OER), however, suffer from sluggish kinetics because of weak catalyst-support interaction and low conductivity. Here, a porous FeNi alloy layer with exposed high active facets was developed on commercially-available bulk FeNi materials. The designed hierarchical structure can significantly promote the interaction between substrate and Ni-Fe layered double hydroxide catalyst, and remain high conductivity of bulk metal substrate. The obtained OER electrode exhibits an ultra-small overpotential of 298 mV to deliver industrial required current density of 1000 mA cm−2, while retaining catalytic activity for 1350 h at room temperature and over 100 h even at 80 ℃. Notably, the alkaline water electrolyzer using this OER electrode exhibits a super-low voltage of 1.46 V for a current density of 10 mA cm−2. Our novel strategy opens up an inexpensive solution for the design of OER electrodes with high catalytic activity and excellent stability.