Dysprosium-induced FeN0.0324-Dy2O3 sites with efficient bifunctional oxygen electrocatalytic reactions for Zn-air batteries

Iron and nitrogen co-doped carbon material (Fe/NC) is considered as a promising catalyst for oxygen reduction reaction (ORR) due to its excellent catalytic activity. However, it is still challenging to further reform the activity of ORR and oxygen evolution reaction (OER). Rare earth elements with unique orbital configurations and catalytic behavior are widely regarded as effective promoters to enhance the electrocatalytic activity of materials. Here, the oxygen electrocatalytic activity of Fe/NC was optimized by the novel addition of dysprosium (Dy) element, denoted as Dy2O3-Fe/NC. The resulting material shows excellent ORR/OER activity in 0.1 M KOH, with a half-potential (E1/2) of 0.914 V and an overpotential of 396 mV (at a current density of 10 mA cm-2). The excellent bifunctional electrocatalytic activity is derived from the close synergistic interaction between Fe and Dy, as well as the newly generated active sites of FeNx-Dy2O3. Zn-air battery assembled with Dy2O3-Fe/NC as cathode catalyst shows a high peak power density (225 mW cm-2) and long-term charge-discharge cycle stability.