Two-in-one strategy to construct bifunctional oxygen electrocatalysts for rechargeable Zn-air battery

Integrating two different catalytic active sites into one composite is a useful 2-in-1 strategy for designing high-efficient bifunctional catalysts, which can easily tailor the activity of each reaction. Hence, we adopt the 2-in-1 strategy to design the metal oxyhydroxide supported on N-doped porous carbons ([email protected]) as the oxygen bifunctional catalyst, where NPC provides the activity for oxygen reduction reaction (ORR) while the metal oxyhydroxide is responsible for oxygen evolution reaction (OER). Results demonstrate that the [email protected] indeed exhibits both super ORR and OER activities. Impressively, using bifunctional [email protected] as the oxygen electrode, the resulting Zn-air battery exhibits outstanding charge and discharge performance with the peak power density of 156.3 mW cm–2, and also exhibits a long-term cycle stability with continuous cyclic charge and discharge of 170 hours that is obviously better than the 20% Pt/C+IrO2 based one. The 2-in-1 strategy in this work can be efficiently extended to design other bi- or multi-functional electrocatalysts.