Ultrafine Fe-modulated Ni nanoparticles embedded within nitrogen-doped carbon from Zr-MOFs-confined conversion for efficient oxygen evolution reaction

Improvement of the low-cost transition metal electrocatalyst used in sluggish oxygen evolution reaction is a significant but challenging problem. In this study, ultrafine Fe-modulated Ni nanoparticles embedded in a porous Ni-doped carbon matrix were produced by the pyrolysis of zirconium metal–organic–frameworks, in which 2,2′-bipyridine-5,5′-dicarboxylate operating as a ligand can coordinate with Ni²⁺ and Fe³⁺. This strategy allows formation of Fe-modulated Ni nanoparticles with a uniform dimension of about 2 nm which can be ascribed to the spatial blocking effect of ZrO₂. This unique catalyst displays an efficient oxygen evolution reaction electrocatalytic activity with a low overpotential of 372 mV at 10 mA·cm^–2 and a small Tafel slope of 84.4 mV·dec^–1 in alkaline media. More importantly, it shows superior durability and structural stability after 43 h in a chronoamperometry test. Meanwhile, it shows excellent cycling stability during 4000 cyclic voltammetry cycles. This research offers a new insight into the construction of uniform nanoscale transition metals and their alloys as highly efficient and durable electrocatalysts.