Journal of Materials Research

Articles

Three-dimensional arrays of graphenated carbon nanotubes

Charles B. Parkera1 c1, Akshay S. Rauta1, Billyde Browna1 p1, Brian R. Stonera2 and Jeffrey T. Glassa3

a1 Department of Electrical and Computer Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina 27708

a2 RTI International, Center for Materials and Electronic Technologies, Durham, North Carolina 27709

a3 Department of Electrical and Computer Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina 27708

Abstract

Graphene and carbon nanotubes (CNTs) are fascinating materials, both scientifically and technologically, due to their exceptional properties and potential use in applications ranging from high-frequency electronics to energy storage devices. This manuscript introduces a hybrid structure consisting of graphitic foliates grown along the length of aligned multiwalled CNTs. The foliate density and layer thickness vary as a function of deposition conditions, and a model is proposed for their nucleation and growth. The hybrid structures were studied using electron microscopy and Raman spectroscopy. The foliates consist of edges that approach the dimensions of graphene and provide enhanced charge storage capacity. Electrochemical impedance spectroscopy indicated that the weight-specific capacitance for the graphenated CNTs was 5.4× that of similar CNTs without the graphitic foliates. Pulsed charge injection measurements demonstrated a 7.3× increase in capacitance per unit area. These data suggest that this unique structure integrates the high surface charge density of the graphene edges with the high longitudinal conductivity of the CNTs and may have significant impact in charge storage and related applications.

(Received October 14 2011)

(Accepted January 18 2012)

Key Words:

  • C;
  • Plasma-enhanced CVD;
  • Energy storage

Correspondence:

c1 Address all correspondence to this author. e-mail: charles.parker@duke.edu

p1 Present address: Luna Innovations Incorporated, 521 Bridge Street, Danville, Virginia 24541

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