Octahedral Cu₂O@Co(OH)₂ Nanocages with Hierarchical Flake‐Like Walls and Yolk‐Shell Structures for Enhanced Electrocatalytic Activity

Unique octahedral yolk‐shell Cu₂O@Co(OH)₂ nanocages are synthesized by a facile Cu₂O self‐templated strategy as efficient glucose oxidation electrocatalysts. Amorphous Co(OH)₂ nanoflakes are formed as octahedral shells through coordinating etching conversion from part of Cu₂O templates. The un‐etched crystalline Cu₂O octahedrons are then remained as cores and voids exist between the cores and shells. The special structure endow these yolk‐shell heterostructure nanocages with abundant active sites, large surface area, and synergistic effect between Cu₂O and Co(OH)₂. The octahedral yolk‐shell Cu₂O@Co(OH)₂ nanocages demonstrate superior electrocatalytic activity for glucose oxidation in terms of high sensitivity of 1340 μA cm⁻² mM⁻¹, low detection limit of 2 μM, wide linear sensing range, and long‐term stability. This strategy might shed lights on the synthesis of various yolk‐shell heterostructure nanocages with controllable structures and enhanced catalytic performances.