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 electro-catalytic 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.