Electronic structure regulation and electrocatalytic mechanism of one-dimensional mesoporous La0.8Sr0.2Mn1-xCoxO3 with bifunctional electrocatalysts towards Zn-air batteries

Abstract

The bimetallic perovskite oxides with outstanding bifunctional catalytic activity and stability are successfully prepared to accelerate multi-electron oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) via molten salt template method. The as-synthesized La0.8Sr0.2Mn0.95Co0.05O3 nanowires exhibit high specific surface area of 27.96 m2 g−1, higher than the most of perovskite oxides synthesized by other researchers. The Co dopants can effectively regulate the electronic structure of perovskites. The one-dimensional mesoporous La0.8Sr0.2Mn0.95Co0.05O3 exhibits excellent bifunctional catalytic activity on account of low ORR overpotential of 435 mV, OER overpotential of 439 mV, and the outstanding battery performance (peak power density of 150.72 mW cm−2 and 177 discharge-charge cycles). More importantly, density functional theory (DFT) calculation demonstrates that the enhanced ORR and OER electrocatalytic mechanism of La0.8Sr0.2Mn1-xCoxO3 originates from the regulated electronic structure with the most positive band center of O 2p, Mn 3d and Co 3d because of Co dopants.