Hierarchically Structured Co 3 O 4 @Pt@MnO 2 Nanowire Arrays for High-Performance Supercapacitors

Abstract

Here we proposed a novel architectural design of a ternary MnO 2-based electrode-a hierarchical Co 3 O 4 @Pt@MnO 2 core-shell-shell structure, where the complemental features of the three key components (a well-defined Co 3 O 4 nanowire array on the conductive Ti substrate, an ultrathin layer of small Pt nanoparticles, and a thin layer of MnO 2 nanoflakes) are strategically combined into a single entity to synergize and construct a high-performance electrode for supercapacitors. Owing to the high conductivity of the well-defined Co 3 O 4 nanowire arrays, in which the conductivity was further enhanced by a thin metal (Pt) coating layer, in combination with the large surface area provided by the small MnO 2 nanoflakes, the as-fabricated Co 3 O 4 @Pt@MnO 2 nanowire arrays have exhibited high specific capacitances, good rate capability, and excellent cycling stability. The architectural design demonstrated in this study provides a new approach to fabricate high-performance MnO 2-based nanowire arrays for constructing next-generation supercapacitors.