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 Co 2 Ni@NC nanoparticles effectively realize abundant synergistic active sites and fast mass transfer for the oxygen evolution reaction (OER). Remarkably, the optimized Co 2 Ni@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.