Facile Synthesis of a Ternary Metal Hydroxide with Acid Treatment as an Effective and Durable Electrocatalyst in Water Oxidation.

Developing low-cost, effective, and durable oxygen-evolution catalysts (OECs) is still a huge challenge owing to the uphill thermodynamic reaction and the involvement of a four-electron and four-proton kinetics process. Herein, a facilely prepared NiCoFe(OH)x /NiOOH/NF electrode affords current densities of 10 and 100 mA cm-2 at overpotentials of 223 and 254 mV, respectively, and a Tafel slope as low as 33.5 mV dec-1 in 1 m KOH, which is superior to NiCoFe(OH)x /NF electrodes electrodeposited with a traditional method. This electrode also displays surprisingly high durability at a current density of 50 mA cm-2 for over 50 hours under alkaline conditions. Component analysis and an electrochemical study revealed that the catalytic activity enhancement of this newly prepared electrode is mainly attributed to the formation of the electrically conductive NiOOH interlayer.