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.