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

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 Ni0.75Fe0.25 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. (C) 2022 Elsevier B.V. All rights reserved.