Porous CoO-CeO2 heterostructures as highly active and stable electrocatalysts for water oxidation.

Abstract We report a CeO 2 incorporated cobalt oxide electrode with abundant nano-sized interfaces. The as-prepared heterostructures exhibit remarkable oxygen evolution reaction (OER) activity and excellent stability, surpassing the pristine cobalt oxide and the state-of-art RuO 2. Further DFT calculations and experimental results indicate that the improved OER performance of CoO-CeO 2 heterostructures originates from the hierarchically porous structure, large surface area and high electron density around Co sites. The armouphous phase is formed during OER test due to surface Ce leaching, which can further promoted the performance of the hybrids. This work elucidates the cooperative effects and in situ transformation of CeO 2 -incorporated cobalt oxide in water oxidation, providing a valuable guideline for designing electrocatalysts. Highlights • The CoO-CeO 2 heterostructures are prepared via a self-assembling method. • The hybrids feature abundant interfaces and hierarchically porous structure. • The hybrids show excellent OER activity and long-term stability. • The enhancement is due to large surface area and strong electronic interaction. • The in situ formed amorphous phase can further improve OER performance. [ABSTRACT FROM AUTHOR]