In situ surface dealumination of intermetallic NiFe aluminides electrocatalysts for enhancing the oxygen evolution

Abstract Herein, based on the mechanical alloying (MA) and in situ electrochemical etching methods, a series of porous Ni–Fe electrocatalysts with different Ni/Fe atomic ratios derived from intermetallic NiFe aluminides have been designed and applied to OER (oxygen evolution reaction) in alkaline solution. As comparing with bulk NiFe aluminides electrocatalyst, the porous electrocatalyst presents higher activity via the etching method. In addition, among all porous samples with different metal stoichiometric ratios, Ni2/3Fe1/3Al shows the highest OER activity with an overpotential of 299 mV at 10 mA cm−2 and a Tafel slope of 58.9 mV dec−1, which can be attributed to the high intrinsic activity and large electrochemical surface area from the leaching of Al. This work provides a promising route to in situ synthesize highly efficient electrocatalysts for water splitting.