Noble-metal-free catalyst with enhanced hydrogen evolution reaction activity based on granulated Co-doped Ni-Mo phosphide nanorod arrays

The development of noble-metal-free electrocatalysts for water splitting is indispensable for the efficient production of hydrogen fuel. Herein, a Co-doped Ni-Mo phosphide nanorod arrays fabricated on porous Ni foam was shown to be an efficient binder-free electrocatalyst for water splitting. This catalyst featured exceptional activity, exhibiting an overpotential of 29 mV at a current density of 10 mA·cm^-2 for the hydrogen evolution reaction, whereas the corresponding precatalyst exhibited an overpotential of 314 mV at a current density of 50 mA·cm^-2 for the oxygen evolution reaction. The achieved electrocatalytic performance provided access to a simple water splitting system, affording a current density of 10 mA·cm^-2 at 1.47 V in 1 M KOH electrolyte. Density functional theory results indicated that Co doping and phosphorization were responsible for the high electrocatalytic performance. Thus, this work paves the way for the development of novel noble-metal-free electrocatalysts for practical H₂ production via water splitting.