Zn constructs micro/nano porous structure to boost efficient oxygen evolution reaction for bulk NiFe alloy

• Zn doped NiFe alloy was prepared by microwave sintering coupled with Zn as space holder. • The NiFe alloy had a low overpotential of 235 mV at 100 mA cm-2 and a low Tafel slope of 26.1 mV dec-1. • A metal (oxy)hydroxide amorphous layer was formed through electrochemical self-reconstruction. • The Zn in the porous NiFe alloy could be dissolved to further improve the specific surface area. • The porous bulk NiFe alloy exhibited superior stability in 1.0 M KOH. Oxygen evolution reaction (OER) electrocatalysts play an important role in producing high purity hydrogen fuels in the water splitting reaction. However, developing bulk catalytic electrode with low-cost and efficient activity for OER is still a challenge. In this paper, the porous bulk NiFe alloys with nanosheet structure were fabricated by a facile microwave sintering powder metallurgy method coupled with Zn as space holder. The obtained porous bulk Ni 0.75 Fe 0.25 alloy exhibits the high catalytic activity for OER with a low overpotential of 235 mV at 100 mA cm −2 , a small Tafel slope of 26.1 mV dec −1 and superior stability in 1.0 M KOH. In addition, the residual Zn in the porous NiFe alloy can be dissolved to further improve the specific surface area, and a metal (oxy)hydroxide amorphous layer is formed through electrochemical self-reconstruction during the OER process. This Zn-doped porous bulk NiFe catalyst with high OER catalytic performance and outstanding stability can become a promising candidate for commercial water splitting.