FeNi3/NiFeOx nanohybrids are efficient electrocatalysts for splitting water into hydrogen and oxygen. By treating NiFeOx nanosheets with hydrogen, these nanohybrids show high activity in both hydrogen and oxygen evolution reactions. They require low onset potentials and only 1.55 V to achieve a current density of 10 mA cm-2 for overall water splitting. This makes them promising for producing hydrogen on a large scale using cost-effective materials.