Hydrophilic Ni(OH)2@CoB nano-chains with shell-core structure as an efficient catalyst for oxygen evolution reaction

Abstract

Enormously active and cost-effective electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are the critical components to produce hydrogen via water splitting using the electricity produced from renewable energy sources. Herein, inspired by the highly electric conductivity of CoB, shell-core structured Ni(OH)2@CoB nano-chains are synthesized as highly active OER catalyst with the assistance of the magnetic field. In the shell-core structured Ni(OH)2@CoB nano-chains, Ni(OH)2 nanoflakes were directly grown onto CoB nano-chains via a facile and wet chemical method. Ni(OH)2 in nanoflake form can provide more available active sites on the surface for electrochemical reaction that is evidenced by high BET surface area (648.9 m2 g−1). At the current density of 10 mA cm−2, the overpotentials of OER occurred on Ni(OH)2@CoB is 320 mV. The obtained Ni(OH)2@CoB also shows very good OER durability without any observable decline for 12 h. The high OER catalytic performance combined with its low-cost makes the Ni(OH)2@CoB nano-chains promising OER catalyst for water splitting in alkaline media.