Cobalt sulfide nanotube arrays grown on FTO and graphene membranes for high-performance supercapacitor application

We implement to build uniform cobalt sulfide nanotube arrays on graphene membrane by two-step hydrothermal method. The cobalt sulfide nanotube arrays/graphene membrane (CoSTA/GM) shows excellent electrochemical performance due to the combination of double-layer capacitance of conductive grapheme membrane and superior pseudocapacitance of the cobalt sulfide nanotube arrays. It can be clearly observed that CoSTA/GM exhibits the specific capacitance value of 245 Fg(-1) at 0.5 A g(-1) in 6 M KOH electrolyte. The capacitance only decreases by 10.3% of the initial capacitance after 1000 cycles, demonstrating the excellent electrochemical stability of such electrode material. Therefore, the results demonstrate that the novel COSTA/GM with enhanced capacitance performance and excellent cycling stability is versatile and may be used for supercapacitors. (C) 2014 Elsevier B.V. All rights reserved.