Metal–Organic-Framework-Derived Yolk–Shell-Structured Cobalt-Based Bimetallic Oxide Polyhedron with High Activity for Electrocatalytic Oxygen Evolution

The development of inexpensive, efficient, and environmentally friendly catalysts for oxygen evolution reaction (OER) is of great significant for green energy utilization. Herein, binary metal oxides (M_xCo_3-xO₄, M = Zn, Ni, and Cu) with yolk-shell polyhedron (YSP) structure were fabricated by facile pyrolysis of bimetallic zeolitic imidazolate frameworks (MCo-ZIFs). Benefiting from the synergistic effects of metal ions and the unique yolk-shell structure, M_xCo_3-xO₄ YSP displays good OER catalytic activity in alkaline media. Impressively, Zn_xCo_3-xO₄ YSP shows a comparable overpotential of 337 mV at 10 mA cm^-2 to commercial RuO₂ and exhibits superior long-term durability. The high activity and good stability reveals its promising application.