Surface constructing FeOOH-decorated hollow cubic NixSy electrocatalyst for efficient oxygen evolution reaction

The development of low-cost, earth-abundant electrocatalysts for oxygen evolution reactions (OER) is of vital significance to alleviate the energy shortage, but it still faces challenges due to the sluggish kinetics of the four-electron transfer process. We synthesized and characterized a series of FeOOH-decorated hollow-cubic Ni x S y electrocatalysts (Ni x S y /FeOOH) with the morphology maintained after the sulfuration treatment and Fe dip-coating. The stoichiometric ratios, heating temperatures, and Fe inputs can affect the morphology and catalytic activity. The as-prepared optimum Ni x S y /FeOOH electrocatalyst exhibited the lowest OER overpotential (250 mV) at 20 mA cm −2 and Tafel slope (53.07 mV dec −1 ) in 1.0 M KOH and maintained long-term stability and good durability. The outstanding OER performance is likely attributed to the synergistic interaction and electron transfer between FeOOH and Ni x S y species. Therefore, the present work provides a promising route for the design and synthesis of stable and efficient OER electrocatalysts.