Synthesis of hierarchical porous NiO nanotube arrays for supercapacitor application

Tailor-made porous nanotube arrays are of great technological interest for the development of high-performance optical and electrochemical energy storage devices. Herein, we report facile successive electro-deposition (ED) methods to fabricate three-dimensional (3D) hierarchical porous NiO nanotube arrays on nickel foam with the help of ZnO nanorod template. The obtained hierarchical porous NiO nanotubes have a diameter of ∼170 nm and consist of interconnected branch nanoflakes of ∼10 nm. The resulting NiO nanotube arrays are well characterized as positive electrode materials for supercapacitor application by cyclic voltammetry (CV) and galvanostatic charge/discharge measurements. Due to the unique architecture, the NiO nanotube arrays exhibit a high capacitance of 675 F g−1 at the 2 A g−1 and 569 F g−1 at 40 A g−1, respectively, as well as good cycling stability. The proposed synthesis method is expected for fabrication of other nanotube arrays for applications in solar cells, gas sensors and Li ion batteries. Hierarchical porous NiO nanotube arrays are prepared via facile successive electro-deposition methods and show superior supercapacitor performance with high capacitance. [Display omitted] •Construct a hierarchical porous NiO nanotube array.•Porous nanotube array shows high pseudo-capacitive properties.•Porous nanotube array structure is favorable for fast ion and electron transfer.