Dealloying-derived Fe-doped Ni(OH)2/Ni foils as self-supported oxygen evolution reaction catalysts

Abstract

Dealloying has been an essential technique for developing nanostructured catalysts for the oxygen evolution reaction (OER). Self-supported active catalysts can be fabricated through an alloying-dealloying process on metal foil surfaces. This study uses a Ga-assisted alloying-dealloying strategy combined with electrooxidation and heteroatom doping to fabricate a Fe-doped Ni(OH)2/Ni self-supported OER catalyst. We find that the surface phase compositions and dealloyed structures can be adjusted by controlling the reaction-diffusion temperature and time. The optimized O-Ni-Fe/200-3 catalyst shows an overpotential of 318 mV to activate a 10 mA cm-2 current density with a Tafel slope of 60.60 mV dec-1. Ex-situ characterization of the catalyst proves that Fe doping promotes the formation of active NiOOH, which contributes to the excellent OER activity. This study extends the Ga-assisted alloying-dealloying strategy and demonstrates the possibility of controlling the microstructure of dealloyed materials by changing the reaction-diffusion conditions.