Bifunctional Water-Splitting Electrocatalysis Achieved by Defect Order in LaA<sub>2</sub>Fe<sub>3</sub>O<sub>8</sub> (A = Ca, Sr)
Surendra B. Karki, Antonis N. Andriotis, Madhu Menon, Farshid Ramezanipour
Abstract
We report the utilization of defect order for development of a bifunctional oxide electrocatalyst. This structure–activity relationship is demonstrated through a disorder–order transformation in LaA2Fe3O8 (A = Ca, Sr). The defect-ordered oxide, LaCa2Fe3O8, shows electrocatalytic activity for oxygen evolution reaction, on par with that of the state-of-the-art precious metal catalyst RuO2. In addition, it is capable of catalyzing the other half-reaction of water-splitting, namely the hydrogen evolution reaction. Importantly, it is an iron-based catalyst and can be used as a single phase bulk material. The most important aspect of this work is the pronounced impact of defect order on the electrocatalytic properties of oxides.