Strategy for Enhancing Interfacial Effect of Bifunctional Electrocatalyst: Infiltration of Cobalt Nanooxide on Perovskite

Abstract

Recently, hybrid catalysts are a critical issue to realize electrocatalysts having competitive price and effective bifunctional activity for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In the case of hybrid catalysts, synergistic effect is observed through electronic and structural reconstructions at the interface between dissimilar oxides, which provides the improved catalytic activity for ORR and OER. Herein, the Co3O4 deposited Nd0.5Sr0.5CoO3−δ (NSC) catalyst is designed to achieve the strain and ligand effect considered as rationale for synergistic effect. A well-designed bifunctional hybrid catalyst (Opt-NSC@Co3O4) is prepared through a useful infiltration technique by tuning the wettability of the precursor solution and the concentration of the Co3O4. Through systematic analysis and re-design, both the onset potential and the limiting current density for ORR and OER are significantly improved with unique microstructure fabricated by the infiltration technique. Opt-NSC@Co3O4 shows outstanding cell performance and excellent stability during 60 h with the discharge–charge voltage gap of 0.5 V for a hybrid Li-air battery. The enhanced electrochemical performance suggests that the derived hybrid catalysts fabricated by the advanced infiltration technique could be promising materials for environmentally benign energy-related applications.