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Free keywords:
EFFICIENT WATER OXIDATION; COBALT OXIDE; CRYSTAL-CHEMISTRY;
ELECTRON-TRANSFER; ALKALINE-SOLUTION; FUEL-CELLS; CATALYSTS;
PERFORMANCE; SURFACE; REDUCTIONChemistry; Science & Technology - Other Topics; Materials Science;
Physics; Electrocatalysis; Oxygen evolution reaction (OER); Layered perovskite;
Electrocatalyst; Co dopant;
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. LaS(r)3Co(1.5)Fe(1.5)O(10-delta), which possesses significantly higher electrocatalytic activity, considerably lower over-potential 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-delta (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-delta, an appropriate possible structure-dependent position of O p-band centre to the Fermi level and an increased amount of highly oxidative oxygen species O-2(2-)/O- in conjunction with a strong OH- adsorption and O-2 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-delta as an earth-abundant, cost-effective, highly active and durable electrocatalyst for OER in energy conversion and storage technologies.
