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

Abstract

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\xa0m2\xa0g−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\xa0mV, OER overpotential of 439\xa0mV, and the outstanding battery performance (peak power density of 150.72\xa0mW\xa0cm−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.