Hydrothermal synthesis of hierarchical mesoporous NiO nanourchins and their supercapacitor application

An urchin-like porous NiO electrode material was synthesized via a simple hydrothermal method. The urchin-like NiO architectures are constructed by numerous nanorods which are assembled by irregular nanoparticles with a diameter ranging from 5 to 10 nm. Electrode materials based on the mesoporous NiO nanourchins exhibited high specific capacitance value (540.5 F g(-1)) at a current density (1 A g(-1)), as well as good cycling stability. This excellent performance may be attributed to following factors: (1) a large specific surface area and more active sites provided by the unique hierarchical architectures; (2) effective contaction and diffusion between the electrode and electrolyte owing to the porous urchin-like structure; (3) the interconnected interspaces among the nanoparticles, which serve as an ion reservoirs to shorten ion diffusion length. (C) 2015 Elsevier B.V. All rights reserved.