Facile synthesis of Ni(OH) 2 nanoarrays on graphene@carbon fabric as dual-functional electrochemical materials for supercapacitors and capacitive desalination.

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