Synthesis of Fe Atom-Doped Monodisperse Co₂P Nanorods with a Dual-Ligand Strategy for Excellent Electrocatalytic...

Cobalt phosphide has been widely used in various catalytic reactions due to its excellent catalytic activity and stability. In contrast to the conventional synthesis of Co₂P nanorods using expensive and toxic trioctylphosphine (TOP), this study employs a dual-ligand strategy to prepare iron-atom-doped monodisperse Co₂P nanorods. The strategy involves the use of triphenylphosphite (TPOP) as a cost-effective and relatively less toxic strong ligand, alongside hexadecylamine (HDA) as a weaker ligand. The resultant atom-doped Co₂P nanorods exhibited a large aspect ratio, providing a plentiful supply of active sites for electrocatalytic hydrogen evolution. In both alkaline and acidic electrolytes, achieving a current density of 10 mA cm^-2 required overpotentials of 91 and 141 mV, respectively, with the optimal Co:Fe molar ratio of 1:0.2. The introduction of Fe atoms through doping increased the electron density at the Co atom sites, thereby enhancing H adsorption. This research offers a cost-effective and relatively low-toxicity method for the controlled fabrication of monodisperse transition-metal phosphide nanorods, enabling efficient catalytic reactions.