FeNi₃/NiFeO<i>_x</i> Nanohybrids as Highly Efficient Bifunctional Electrocatalysts for Overall Water Splitting

Abstract

Earth‐abundant, low‐cost, and highly active bifunctional electrocatalysts are of significant importance to the large‐scale production of hydrogen from water electrolysis. Herein, it is reported that novel FeNi 3 /NiFeO x nanohybrids display high electrocatalytic activities in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). These FeNi 3 /NiFeO x nanohybrids are obtained with the unique hydrogenation treatment of NiFeO x nanosheets. Small onset potentials of ≈20 and 240 mV are obtained for HER and OER, respectively, benefited from the synergistic effect of FeNi 3 and NiFeO x . Only a small voltage of 1.55 V is needed to reach a current density of 10 mA cm −2 for the overall water splitting in an alkaline electrolyzer when using FeNi 3 /NiFeO x as both cathode and anode catalysts. This is one of the best performance of electrocatalysts for HER and OER, shining the bright future for earth‐abundant, low‐cost bifunctional electrocatalysts for large‐scale production of hydrogen from water electrolysis.