Synthesis of three-dimensional tungsten oxide cactus-shaped nanostructures supported on carbon nanotubes template

Abstract

We report that three-dimensional cactus-shaped tungsten oxide WO x (x = 2-3) nanostructures have been synthesized over a large area using a simple one-step metal-organic chemical vapor deposition (MOCVD) technique at unusually lower temperatures than previously reported, making use of vertically aligned carbon nanotubes (CNTs) as the base template in a core-shell configuration. Each WO3 crystallite forms independently perpendicular to the CNT spine resulting in the cactus-like structures. The presence of these structures has been shown to lead to improved electron emission properties, where the turn-on field was lowered from pristine CNTs at 3.47-2.31 V μm-1 with an increase in the field enhancement factor from ∼1225 to ∼3985. The growth mechanism of the nanostructures is discussed. © 2011 The Electrochemical Society.