Ce Hydroxide-Interfaced NiFe Sulfide Electrocatalyst with Improved Performance for the Oxygen Evolution Reaction

The development of electrochemically inexpensive, durable, and active electrocatalysts for the oxygen evolution reaction (OER) is attracting considerable attention. The heterogeneous interfacing might regulate the electronic structure and further improve the electrochemical activity. Herein, a Ce(OH)₃ nanoparticle-interfaced Fe-doped nickel sulfide (Ce(OH)₃@Fe-Ni₃S₂) electrocatalyst was prepared to improve the OER performance. The fabricated electrocatalyst displayed excellent intrinsic activity and long-term stability in 1 M KOH for the OER. The catalyst shows an ultralow overpotential of 195 mV at a current density of 10 mA cm^-2 and a Tafel slope of 52 mV dec^-1, which are remarkably smaller than those of the control samples. This excellent electrocatalytic activity is attributed to the incorporation of Ce(OH)₃ nanoparticles on the surface of the Fe-Ni₃S₂ nanosheet, which increases the electrochemical activity and enlarges the active surface area of the catalyst. In comparison to previous nonprecious OER electrocatalysts, the prepared Ce(OH)₃@Fe-Ni₃S₂ exhibits greater electrocatalytic activity and longer durability, allowing for the selection of new electrocatalysts for practical applications.