Constructing abundant active interfaces in ultrafine Ru nanoparticles doped nickel-iron layered double hydroxide to promote electrocatalytic oxygen evolution

Due to the inherent sluggish kinetics of oxygen evolution reaction (OER), designing high-efficient and stable electrocatalysts is essential and urgent for the practical use of energy conversion devices. The transition-metal based layered double hydroxide (LDH) is considered as an alternative candidate with desired OER activity, while its catalytic performance is impeded by the limited active sites, poor conductivity and durability. Herein, the ultrafine and well-dispersed Ru nanoparticles doped NiFe LDH (Ru-NiFe-LDH) is designed as highly efficient electrocatalyst for OER. Benefiting from synergistic electronic modulation, as well as the abundant active interfaces, between Ru nanoparticles and NiFe LDH, Ru-NiFe-LDH shows superior electrocatalytic activity in alkaline electrolyte with a low overpotential of 256 mV at the current density of 50 mA cm(-2) Moreover, the RuNiFe-LDH exhibits comparable activity toward oxygen reduction (ORR). As a concept verification, a homemade Zn-air battery assembled by Ru-NiFe LDH presents desired performance and stability under practical operating conditions. This work may broaden the family of advanced electrocatalysts for electrochemical energy conversion.