CeO<i>_x</i>-Decorated Hierarchical NiCo₂S₄ Hollow Nanotubes Arrays for Enhanced Oxygen Evolution Reaction Electrocatalysis

Abstract

Developing hollow self-supported nanotube arrays with hierarchical microporous and abundant multiactive sites shows great promise for oxygen evolution reaction (OER) electrocatalysis. Herein, a facile and low-cost strategy of NiCo₂S₄ hollow nanotubes arrays decorated with CeO<i>_x</i> nanoparticles (NPs) assembled on a flexible support carbon cloth (CC) for enhanced OER performance is reported. The obtained hierarchical nanoarrays CeO<i>_x</i>/NiCo₂S₄/CC exhibited excellent activity toward OER with an overpotential (270 mV) at 10 mA cm^-2, relatively weak Tafel slope, and distinguished durability. CeO<i>_x</i>/NiCo₂S₄/CC nanoarrays not only provide fast electronic transmission and well-defined connection to the substrate but also defective sites and electron transfer by the introduction of CeO<i>_x</i> NPs. This new strategy was offered to construct low-cost and effectively hierarchical structural electrocatalysts containing rare-earth species.