Preparation of 1D CuO Nanorods by Means of a Metal Ion Containing Ionic Liquid and Their Supercapacitance

1D CuO nanorods have been successfully prepared in the presence of a metal ion containing ionic liquid, namely bis(1-hexadecyl-3-methylimidazolium) tetrachlorocuprate ([C16mim]2CuCl4) under solvothermal conditions. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), FTIR spectroscopy and the Brunauer-Emmet-Teller (BET) surface area method. The nanorods synthesized from metal ion containing ionic liquids showed good crystallinity, well-defined morphologies, small sizes and large BET surface areas. The effect of changing the alkyl chain length of the ionic liquid's cation on the morphology of CuO has been investigated. It was found that the ionic liquid acted not only as a Cu source but also as a solvent and template for the fabrication of 1D CuO nanorods. In addition, the capacitance of CuO as an electrode material was tested by cyclic voltammetry and chronopotentiometric measurements. With the morphologies changing from nanoparticles to nanorods, the BET surface area of CuO was significantly increased from 38.79 m2g1 to 88.46 m2g1 and the specific capacitance of CuO also increased from 58.25 Fg1 to 498.75 Fg1. Thus, the CuO nanorods are promising for the future development of supercapacitors.