Boosting oxygen evolution reaction activity by tailoring MOF-derived hierarchical Co–Ni alloy nanoparticles encapsulated in nitrogen-doped carbon frameworks

The growing demand for sustainable energy has led to in-depth research on hydrogen production from electrolyzed water, where the development of electrocatalysts is a top priority. We here report a controllable strategy for preparing the cobalt–nickel alloy nanoparticles encapsulated in nitrogen-doped porous carbon by annealing a bimetal–organic framework. The delicately tailored hierarchical Co2Ni@NC nanoparticles effectively realize abundant synergistic active sites and fast mass transfer for the oxygen evolution reaction (OER). Remarkably, the optimized Co2Ni@NC exhibits a small overpotential of 310 mV to achieve a current density of 10 mA cm−2 and an excellent long-term stability in alkaline electrolyte. Furthermore, the underlying synergistic effect mechanism of the Co–Ni model has been pioneeringly elucidated by density functional theory calculations.