Calcium-doped lanthanum nickelate layered perovskite and nickel oxide nano-hybrid for highly efficient water oxidation

Perovskite oxides have attracted great attention recently for its high intrinsic activity in oxygen evolution reaction (OER) in electrochemical energy storage and conversion systems. However, their specific activity and durability require substantial enhancement to meet the requirement of the practical applications. Here, we demonstrate for the first time that a layered perovskitemetal oxide nano-hybrid electrocatalyst synthesized through a one-pot combustion process shows remarkably high OER activity in alkaline solution. The hybrid consists of two major phases, i.e. NiO and K2NiF4-type layered perovskite (La0.613Ca0.387)(2)NiO3.562, showing synergistically enhanced OER activity and excellent durability under harsh OER operating conditions. The NiO-(La0.613Ca0.387)(2)NiO3.562 hybrid exhibits the lowest Tafel slope (similar to 42 mV dec(-1)) and highest mass activity (52.2 mA mg(-1) @ 1.63 V vs RHE) among all catalysts studied including noble metal oxide RuO2 and well-known perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-delta. (C) 2014 Elsevier Ltd. All rights reserved.