An effective pre-catalytic electrode based on iron/nickel hydroxyquinoline for water oxidation

Abstract

Oxygen evolution reaction is related in various energy-related devices including water splitting and metal-air batteries. Herein, the reaction between Fe3+, Ni2+, and 8-hydroxyquinoline was used to generate iron/nickel hydroxyquinoline salts (FeNi-HQ), which were loaded on a nickel framework for water oxidation. The formed coordination compound contains iron/nickel bimetal sites that show strong interaction between them, and so presents excellent electrocatalytic activity for oxygen evolution after an electrochemical activation process. Driven by a small overpotential of 293 mV, the activated catalytic electrode can provide 50 mA cm−2 of current density with higher stability. Investigation on the catalyst after long time catalytic operation confirms that the surface layer is activated with the formation of metal oxyhydroxides. This study provides a new and effective pre-catalytic electrode for oxygen evolution.