Three-Dimensional Carbon-Coated Treelike Ni 3 S 2 Superstructures on a Nickel Foam as Binder-Free Bifunctional Electrodes.

Three-dimensional (3D) nanostructures are commonly endowed with numerous active sites, large specific surface area and good mechanical strength, which makes them as an efficient candidate for energy storage and conversion. Herein, by considering the advantages of 3D nanostructures we successfully fabricated carbon coated nickel sulfide on nickel foam (C@NS@NF) with a unique 3D tree-like superstructures via a two-step hydrothermal process. In virtue of its hierarchical superstructures, 3D tree-like architecture and carbon shell encapsulation, the as-fabricated carbon coated Ni3S2 can be directly served as binder-free bifunctional electrodes for supercapacitor and hydrogen evolution reaction (HER), where high specific areal capacitances (6.086 F cm-2 at 10 mA cm-2) for supercapacitors and low overpotential (92 mV at 10 mA cm-2) for electrocatalyst have been demonstrated. These inspiring results of this material makes it as a potential candidate for energy storage and conversion.