Facile synthesis of Co and Ce dual-doped Ni₃S₂ nanosheets on Ni foam for enhanced oxygen evolution reaction

Developing efficient and stable oxygen evolution reaction (OER) electrocatalysts via doping strategy has well-documented for electrochemical water splitting. Herein, a homogeneous structure (denoted as Co/Ce-Ni₃S₂/NF) composed of Co and Ce dual doped Ni₃S₂ nanosheets on nickel foam was synthesized by a facile one-step hydrothermal method. Co and Ce dopants are distributed inside the host sulfide, thereby raising the active sites and the electrical conductivity. Besides, the CeO_x nanoparticles generated by part of the Ce dopants as a cocatalyst further improve the catalytic activity by adding defective sites and enhancing the electron transfer. As a consequence, the obtained Co/Ce-Ni₃S₂/NF electrode exhibits better electrocatalytic activity than single Co or Ce doped Ni₃S₂ and pure Ni₃S₂, with low overpotential (286 mV) at 20 mA·cm^-2, a small Tafel slope and excellent long-term durability in strong alkaline solution. These results presented here not only offer a novel platform for designing transition metal and lanthanide dual-doped catalysts, but also supply some guidelines for constructing catalysts in other catalytic applications.