Ni-Co@carbon nanosheet derived from nickelocene doped Co-BDC for efficient oxygen evolution reaction

Highlights: • Ni-Co@carbon nanosheet was obtained by direct carbonization of nickelocene@Co-BDC • The obtained bimetallic electrocatalyst exhibits an unprecedentedly high OER activity. • Density functional theory studies reveal that the synergetic effect of Ni and Co. In recent years, metal–organic framework (MOF) have become versatile precursors for preparation of electrocatalysts toward oxygen evolution reaction (OER). In this work, a novel and facile MOF-mediated synthesis strategy is demonstrated for constructing efficient OER catalysts. The nickelocene molecules were introduced into the channels of 2-D layered MOF (Co-BDC) to form the nickelocene@Co-BDC hybrids by vapor deposition method. The Ni-Co@carbon nanosheet was obtained by direct carbonization of nickelocene@Co-BDC. The obtained bimetallic electrocatalyst exhibits an unprecedentedly high OER activity with a small overpotential (243 mV at current density of 10 mA cm⁻²) and a low Tafel slop (66.97 mVdec^-1) in 1.0 M KOH aqueous solution, which is better than the most reported non-noble metal based electrocatalysts. Density functional theory (DFT) studies reveal that the synergetic effect of Ni and Co active sites affords superior electrocatalytic properties, further indicating this binary metal electrocatalyst is a promising candidate for sustainable energy applications.