High-entropy oxide, (FeCoNiMnV)xO, boost the oxygen evolution

The sluggish kinetics of the oxygen evolution reaction (OER), an essential half-reaction of water splitting, lead to high OER overpotential and low energy-conversion efficiency, hampering its industrial application. Therefore, considerable attention has been paid to the development of efficient catalysts to accelerate the OER. In this study, we synthesized the high-entropy oxides [(FeCoNiMnV)_xO] and used them as efficient OER catalysts. A simple oil-phase method was used to synthesize (FeCoNiMnV)_xO. The catalytic performances of the (FeCoNiMnV)_xO catalysts were modified by tuning the reaction temperature. The optimized (FeCoNiMnV)_xO catalyst exhibited multiple elemental interactions and abundant exposed active sites, leading to an overpotential of approximately 264 mV to reach a current density of 10 mA cm⁻² in 1 M KOH and stability of 50 h at 1000 mA cm⁻². Thus, a highly active OER catalyst was synthesized. This study provides an efficient approach for the synthesis of high-entropy oxides.