From Nickel Foam to Highly Active NiFe‐based Oxygen Evolution Catalysts

Abstract

AbstractA key challenge for the large‐scale application of the oxygen evolution reaction (OER) is the synthesis of active, cheap and robust catalysts. Here, a straightforward procedure to form novel porous and highly active multimetallic oxygen evolution catalysts was reported. They were derived from an original dendritic nickel foam (NiNF) using two strategies: i) Fe‐doping; and ii) Fe/Cr‐doping. A bimetallic NiFe catalyst, formed through controlled acid treatment followed by a simple galvanic exchange procedure proved remarkably active in 1 m KOH with a very low overpotential value of η200=276 mV at 200 mA cm−2 and a very low Tafel slope of 25 mV dec−1. A trimetallic FeNiCr catalyst, containing 11 % Cr, was also synthesised through electrodeposition and partial Cr leaching, to form a stable OER catalyst displaying a very low overpotential value of η200=279 mV at 200 mA cm−2 and a Tafel slope of 29 mV dec−1. These two novel catalysts are among the best performing OER catalysts reported so far.