Yolk-shell nanostructural Ni2P/C composites as the high performance electrocatalysts toward urea oxidation

Abstract Highly active and low-cost catalytic electrodes for urea oxidation reaction (UOR) are always crucial for exploration of urea fuel cells. Herein, novel york-shell-structural Ni2P/C nanosphere hybrids (Ni2P/C-YS) are rationally constructed via a hydrothermal method and subsequent phosphidation treatment under different temperature ranging from 250 °C to 450 °C for UOR applications. In the in-situ constructed hollow york-shell structure, the coupling of conductive carbon materials and active Ni2P allows numerous interfaces facilitating the electron transfer and thereby accelerating the catalytic kinetics. The results demonstrate that Ni2P/C-YS-350 nanocomposite can boost the UOR process with a low potential of 1.366 V vs. RHE at a current density of 50 mA/cm2 in alkaline electrolyte and afford the superior durability with negligible potential decay after 23 h. This study presents that the carbon coated Ni2P hybrid with the optimized crystallinities and hollow york-shell configurations can be a promising candidate for application in urea fuel cells.