Structure engineering of amorphous P–CoS hollow electrocatalysts for promoted oxygen evolution reaction

Oxygen evolution reaction (OER) is a key process involved in many energy-related conversion systems. An ideal OER electrocatalyst should possess rich active sites and optimal binding strength with oxygen-containing intermediates. Although numerous endeavors have been devoted to the modification and optimization of transition-metal-based OER electrocatalysts, they are still operated with sluggish kinetics. Herein, an ion-exchange approach is proposed to realize the structure engineering of amorphous P–CoS hollow nanomaterials by utilizing the ZIF-67 nanocubes as the precursors. The precise structure control of the amorphous hollow nanostructure contributes to the large exposure of surface active sites. Moreover, the introduction of phosphorus greatly modifies the electronic structure of CoS2, which is thus favorable for optimizing the binding energies of oxygenated species. Furthermore, the incorporation of phosphorus may also induce the formation of surface defects to regulate the local electronic structure and surface environment. As a result of this, such P–CoS hollow nanocatalysts display remarkable electrocatalytic activity and durability towards OER, which require an overpotential of 283 mV to afford a current density of 10 mA cm−2, outperforming commercial RuO2 catalyst.