Hierarchical coral-like NiMoS nanohybrids as highly efficient bifunctional electrocatalysts for overall urea electrolysis

Novel hierarchical coral-like Ni-Mo sulfides on Ti mesh (denoted as HC-NiMoS/Ti) were synthesized through facile hydrothermal and subsequent sulfuration processes without any template. These non-precious HC-NiMoS/Ti hybrids were explored as bifunctional catalysts for urea-based overall water splitting, including the anodic urea oxygen evolution reaction (UOR) and cathodic hydrogen evolution reaction (HER). Due to the highly exposed active sites, excellent charge transfer ability, and good synergistic effects from multi-component reactions, the HC-NiMoS/Ti hybrid exhibited superior activity and high stability, and only a cell voltage of 1.59 V was required to deliver 10 mA·cm^–2 current density in an electrolyte of 1.0 M KOH with 0.5 M urea.