Oxygen evolution catalyzed by Ni-Co-Nb ternary metal sulfides on plasma-activated Ni-Co support

As a four-electron-proton coupled reaction, the oxygen evolution reaction (OER) requires a high overpotential for electrocatalytic water splitting. Most of the reported OER catalysts still need higher overpotentials than the thermodynamic water decomposition potential (1.23 V). Therefore, developing the efficient and cost-effective OER electrocatalysts remains a challenge in the electrocatalysis filed. Herein, multiphase Ni-Co-Nb sulfides (NiCoNbS_x) are in-situ engineered on the plasma-activated nickel-cobalt foam (PNCF), and the synthesized NiCoNbS_x/PNCF exhibits rich heterointerfaces and active sites, causing a high OER performance in an alkaline medium. The NiCoNbS_x/PNCF catalyst features the low overpotentials of 48 and 382 mV for delivering the current densities of 10 (j₁₀) and 1000 mA cm^-2 (j₁₀₀₀), with a good electrocatalytic stability. The theoretical calculations reveal that the heterojunction interface of NiS (401)-Co₉S₈ (440) acts as the active center for OER. These results provide a new effective surface modification approach and insights into catalytic processes enabling water electrolysis pursued for clean and sustainable energy applications.