Leaf-like 2D nanosheet as efficient oxygen reduction reaction catalyst for Zn-air battery

Abstract Replacing Pt-based catalysts to alleviate energy and environmental crises for oxygen reduction reaction in fuel cells has become increasingly urgent. Herein, Fe and Co dual active sites and leaf-like 2D nanosheets are prepared by a low-cost and facile approach derived from a leaf-like zeolitic imidazolate framework (ZIF-L) precursor. The non-precious dual metal leaf-like 2D electrocatalyst exhibits better positive onset (0.98 V vs. RHE) and half-wave potential (0.831 V vs. RHE) compared with commercial Pt/C in alkaline media. This excellent performance is attributed to the structural characteristics of the leaf-like 2D nanosheet, including the large surface area and the synergistic effect of the Co and FeCo alloy and the nitrogen-doped carbon. The large surface area provides a large number of accessible active sites, and the dual metal and nitrogen-doped carbon enhance the mass transfer kinetics. Above all, the unique leaf-like 2D structure improves the activity and durability of oxygen reduction reaction. It is worth that the Zn-air battery we have made as air cathode demonstrates the excellent power density, specific capacity and stability. Impressively, the flexible battery has the outstanding performance.