Facially Synthesis of Ni(OH) <sub>2</sub> Nanoarray on RGO@ Carbon Fabric as Dual-Functional Electrochemical Materials for Supercapacitors and Capacitive Desalination

Abstract

A high performance Ni(OH)2 nanoarray on RGO@ carbon fabric nanocomposites with hierarchical nanostructures were facilely synthesized, which involves i. coating of graphene on carbon fabric; ii, in-situ growth of Ni(OH)2 nanoarray on graphene surface. It is found that Ni(OH)2 nanoplates grown evenly on the surfaces of graphene without stacking. This unique structure of electrode material favors to a higher electrochemical active sites, which endows the enhancing capacity performance. The morphology and the microstructure of the as-prepared composites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) techniques. Capacitive properties of the synthesized electrodes were studied using cyclic voltammetry, charge/discharge, and electrochemical impedance spectroscope in a three-electrode experimental setup. Favors from the unique structure of Ni(OH)2/RGO@carbon fabric nanocomposites, this material as dual-functional electrodes shows decent performance for both supercapacitor and capacitive desalination (CDI). The specific capacitance is calculated to be 1325 F g-1 at 1 A g-1, moreover, this material shows a high rate capability, the capacitance can be maintained at 612 F g-1 even at 10 A g-1. Besides, the performance of it as potential CDI electrodes were explored. Such high-performance Ni(OH)2/RGO@carbon fabric hierarchical nanostructures can offer great promise in large-scale energy storage device applications.