FeNi3/NiFeOx Nanohybrids as Highly Efficient Bifunctional Electrocatalysts for Overall Water Splitting

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 FeNi3/NiFeOx nanohybrids display high electrocatalytic activities in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). These FeNi3/NiFeOx nanohybrids are obtained with the unique hydrogenation treatment of NiFeOx nanosheets. Small onset potentials of ≈20 and 240 mV are obtained for HER and OER, respectively, benefited from the synergistic effect of FeNi3 and NiFeOx. 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 FeNi3/NiFeOx 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.