LAUSR

Abstract To accelerate the kinetics of oxygen evolution reaction (OER) on H2O oxidation regarding the energy conversion and storage approaches, the discovery and design of desirable cost-effective and highly efficient electrocatalysts is of prime importance. This study demonstrates a novel layered perovskite via Co-doping strategy, i.e. LaSr3Co1.5Fe1.5O10-δ, which possesses significantly higher electrocatalytic activity, considerably lower overpotential and Tafel slope, remarkably higher mass activity (MA) and specific activity (SA) together with a better long-term stability than the undoped parent perovskite, the state-of-the-art IrO2 and the most active Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) under harsh OER cycling conditions in alkaline solution. These merits mainly originate from the presence of partial oxidation of surface Co3+ to Co4+ in LaSr3Co1.5Fe1.5O10-δ, an appropriate possible structure-dependent position of O p-band centre to the Fermi level and an increased amount of highly oxidative oxygen species O22-/O- in conjunction with a strong OH- adsorption and O2 desorption abilities. These findings not only improve the electrocatalytic activities of the layered perovskite family via optimal doping but also highlight the potential application of LaSr3Co1.5Fe1.5O10-δ as an earth-abundant, cost-effective, highly active and durable electrocatalyst for OER in energy conversion and storage technologies.