Self-standing non-noble metal (Ni–Fe) oxide nanotube array anode catalysts with synergistic reactivity for high-performance water oxidation

Abstract

The oxygen evolution reaction (OER) is coupled with a number of important cathodic processes, for instance water splitting for hydrogen production and other energy storage devices based on O₂–H₂O chemistries such as metal–air batteries and unitized regenerative fuel cells, but they are limited by the slow kinetics. Attempts to solve this problem have received wide attention recently. However, accessing and stabilizing high-oxidation-state catalytically active species to further improve the high performance for the OER has been considered a huge challenge. Here, we report a Ni–Fe oxide-based nanotube array electrode, novel in design, with strong durability and excellent and synergistically enhanced catalytic performance for the OER. The OER electrode, with a nanotube array nanostructure, shows the remarkable features of a small overpotential of 0.28 V, favourable electrode kinetics and high stability, comparing favorably with the reported performances of the best OER electrocatalysts (IrO₂), which is attributed to the formation and stabilization of the favourable OER catalytically active species NiOOH that is produced and reinforced by the introduction of Fe into nanostructured materials. This feasible strategy affords a new strategy for the development of effective and robust OER electrodes.