Formation of Single-Holed Cobalt/N-Doped Carbon Hollow Particles with Enhanced Electrocatalytic Activity toward Oxygen Reduction Reaction in Alkaline Media

Design and construction of metal-organic framework (MOF) composite precursors have recently been considered as a promising strategy for the preparation of different structured metal/carbon-based functional materials. Here, an MOF composite-assisted strategy to synthesize single-holed cobalt/N-doped carbon hollow particles is reported. The yolk-shell polystyrene@zeolitic imidazolate framework-67 (PS@ZIF-67) composite precursors are first synthesized, followed by a controlled pyrolysis to obtain cobalt/N-doped carbon hollow particles with a large single hole on each shell. Moreover, the MOF-coating approach reported in this work can be extended to prepare various core-shell ZIF-67 composites with different structures and compositions. Benefiting from the structural and compositional advantages, the as-derived single-holed cobalt/N-doped carbon hollow particles manifest superior electrocatalytic oxygen reduction performance with high activity and excellent durability.