A hierarchical Ni–Co–O@Ni–Co–S nanoarray as an advanced oxygen evolution reaction electrode

Abstract

Developing an efficient electro-catalyst for water oxidation is essential for improving the performance, which holds the key for a number of energy conversion and storage devices. Here we report an effective method for fabricating a Ni–Co–O@Ni–Co–S hierarchical nanoarray, which showed a significantly improved activity relative to Ni–Co–O nanowire arrays for oxygen evolution reactions. The enhanced performance was attributed to the secondary formed Ni–Co–S nanoplatelets which not only acted as efficient electrocatalysts, but also facilitated the electrolyte penetration and increased the surface area.