Low-temperature and anhydrous preparation of NixFey-LDHs as an efficient electrocatalyst for water and urea electrolysis

Abstract

Oxygen evolution reaction (OER) and urea oxidation reaction (UOR) limit the efficiency of electrolytic water and urea oxidation to hydrogen formation processes, respectively. Here, a facile low-temperature anhydrous method was used to synthesize NixFey-LDHs catalysts with good eletrocatalytic activity for OER and UOR. With urea oxidation as an alternative anodic reaction, the anodic oxidation potential decreased significantly to 1.37 V@20 mA cm−2. The electrolyzer voltage decreased to only 1.41 V@10 mA cm−2 with the Ni9Fe1-LDHs anode. It was demonstrated that Fe induced the formation of Ni(III) on the surface and promoted the reversible Ni(II)/Ni(III) transition.