Multilayer super-short carbon nanotube/reduced graphene oxide architecture for enhanced supercapacitor properties

Zero-dimension super-short carbon nanotubes (SSCNTs) with aspect ratio of less than 5 could be synthesized by tailoring the raw multi-walled carbon nanotubes (MWCNTs) with a simple ultrasonic oxidation-cut method. The introduction of SSCNTs adequately increases the utilization of closed pore volumes of MWCNTs and effectively inhibits the stacking of reduced graphene oxides (RGOs). Thus an RGO/SSCNT is prepared by a wet-chemical route for supercapacitors. The topography and structure of the as-prepared materials are characterized by scanning electron microscope and nitrogen sorption isotherms, and their supercapacitor properties are also investigated. The results show that the SSCNTs could cross the gaps of RGO layers to form a three-dimensional (3D) multilayer architecture, with a much higher specific capacitance (244 F g(-1) at 50 mV s(-1)) than that of RGO (136 F g(-1)) and RGO/MWCNTs (91 F g(-1)). Furthermore, the RGO/SSCNTs displays a high specific capacitance of 210 F g(-1) at the ultrahigh scan rate of 1000 mV s(-1) (85% capacity retention compared to 50 mV s(-1)). These attractive results indicate that RGO/SSCNT with 3D multilayer architecture is a promising graphene-based material for high power supercapacitors. (C) 2013 Elsevier B.V. All rights reserved.