Advancing electrocatalytic water oxidation performances with tungsten-enhanced perovskite cobaltites

The sluggish kinetics of the oxygen evolution reaction (OER) is generally undesirable for advanced green hydrogen production through renewable energy unless the employment of efficient catalysts. Perovskite-type oxide materials have been recognized as promising alternatives to overcome the kinetic limitations of OER. Nonetheless, despite extensive research endeavors, the electrochemical activity and durability of versatile perovskite candidates still fall short of expectations. Herein, a novel perovskite cobaltite BaCo 0.6 Fe 0.2 W 0.2 O 3- delta (BCFW0.2), enlightened by tungsten incorporation strategy, is proposed as a reliable electrocatalyst for OER. Characterization analyses unravel that the manipulation of tungsten substitution in BCFW0.2 leads to the formation of high-symmetry crystal structure and more reactive oxygen species, which in turn promotes favorable oxygen catalytic behavior. Accordingly, the BCFW0.2 catalyst exhibits significantly lower overpotential of 273 mV at a current density of 10 mA cm -2 and remarkably smaller Tafel slope of 42.34 mV dec -1 relative to its undoped counterpart, as well as considerable operational durability under various current densities. The mechanism of lattice oxygen activation in BCFW0.2 is also explored. This study paves a constructive avenue for the rational design of high-performance perovskite-based derivative catalysts.