Facile synthesis of novel metal-organic nickel hydroxide nanorods for high performance supercapacitor

Novel one-dimensional metal-organic nickel hydroxide nanorods were synthesized via a facile hydrothermal process and used as electrode materials for supercapacitors. The chemical formula of as-prepared nickel-based metal organic frameworks (MOFs) using salicylate ions as organic linkers can be denoted as [Ni(HOC6H4COO)(1.48)(OH)(0.52)center dot 1.1H(2)O] by elemental and XPS analysis. The Ni-based MOF nanorods are very uniform in size with an average length of about 900 nm and diameter of 60 nm. They exhibited a high specific capacitance, exceptionally high rate capability and excellent cycling stability. Capacitances of 1698, 1385, 1278, 1068, 998 and 838 F g(-1) can be achieved at rates of 1, 2, 3, 5, 7 and 10 A g(-1), respectively. In the mean time, ca. 94.8% capacitance was retained after 1000 cycles at 1 A g(-1). Importantly, the constructed Ni-based MOF nanorods/graphene asymmetric supercapacitor reveals outstanding capacitive behaviors with a specific capacitance of 166 F g(-1) at a current density of 1 A g(-1) and eminent rate capability. These outstanding electrochemical properties demonstrate that the as-prepared Ni-based MOF nanorods are efficient electrode materials for supercapacitors and have a greatly promising application in the development of high-performance electrochemical energy storage devices. (C) 2016 Elsevier Ltd. All rights reserved.