Bifunctional electrocatalysts for water splitting based on earth-abundant metals are highly desired. Herein, we show the structure-activity relationship in oxygen-deficient perovskite oxides for electrocatalytic activity toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline medium. We have studied the role of structural transformation as a result of defect-order in LaA2Fe3O8 (A = Ca, Sr), leading to bifunctional electrocatalysis. The bilayered brownmillerite LaCa2Fe3O8 that has a structure with ordered defects, shows electrocatalytic activity for OER that competes with that of the state-of-the-art precious metal catalyst RuO2. Additionally, this material catalyzes HER with an overpotential that is comparable to several reported HER electrocatalysts. Importantly, this iron-based catalyst shows the impact of defect-order on electrocatalytic properties for water splitting, where the structural transformation as a result of defect-order results in a significant improvement of the electrocatalytic activity.

Water splitting electrocatalysis in alkaline condition enhanced by defect-order in LaCa2Fe3O8.

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.