Metal–Organic Framework Hybrid‐Assisted Formation of Co₃O₄/Co‐Fe Oxide Double‐Shelled Nanoboxes for Enhanced Oxygen Evolution

Abstract

Rational design of complex metal-organic framework (MOF) hybrid precursors offers a great opportunity to construct various functional nanostructures. Here, a novel MOF-hybrid-assisted strategy to synthesize Co₃ O₄ /Co-Fe oxide double-shelled nanoboxes is reported. In the first step, zeolitic imidazolate framework-67 (ZIF-67, a Co-based MOF)/Co-Fe Prussian blue analogue (PBA) yolk-shell nanocubes are formed via a facile anion-exchange reaction between ZIF-67 nanocube precursors and [Fe(CN)₆ ]^3- ions at room temperature. Subsequently, an annealing treatment is applied to prepare Co₃ O₄ /Co-Fe oxide double-shelled nanoboxes. Owing to the structural and compositional benefits, the as-derived Co₃ O₄ /Co-Fe oxide double-shelled nanoboxes exhibit enhanced electrocatalytic performance for oxygen evolution reaction in alkaline solution.