FeCoNiW medium entropy alloys loaded onto N-doped carbon skeletons as efficient electrocatalysts for oxygen evolution reactions†
Abstract
Medium entropy alloys, consisting of four elements in close to isotropic proportions, have attracted a great deal of attention because of their unique properties (excellent strength, corrosion resistance, etc.). Here, we present a series of quaternary medium entropy alloy FeCoNiW electrocatalysts loaded onto nitrogen-doped carbon (NC) skeletons. The prepared medium entropy alloy catalysts have excellent OER catalytic activity and stability. In alkaline media, the FeCoNiW-NC electrocatalysts annealed at 350 °C were able to achieve an overpotential as low as 225 mV at a current density of 10 mA cm−2, which is 55 mV lower than that of the commercial RuO2, while it has a smaller Tafel slope of 54 mV dec−1. The introduction of W leads to a change in the electronic structure of the FeCoNi alloy and increases the specific surface area of the catalyst, exhibiting excellent performance. This work contributes to the exploration of OER catalysts by opening new avenues for the design of efficient and economical OER electrocatalysts.