Growth and Plasma Functionalization of Carbon Nanotubes

This review presents recent results about the growth of vertically aligned carbon nanotubes (VACNTs) by plasma enhanced chemical vapor deposition (PECVD) and water assisted CVD. Modification of VACNTs by surface specific plasma treatments as well as by MnO2 electrodeposition, allows the optimization of the CNTs physico-chemical properties. Incorporation of oxygen and nitrogen functional groups by oxygen plasma, water plasma and nitrogen plasma are discussed in detail. The surface modification not only decorates the CNTs with desired functional groups, but also increases their surface area and makes them suitable for electrochemical, biological and environmental applications. In order to study the effects of surface functionalization on the CNTs properties, electrochemical and adsorption/desorption measurements were carried out. Both plasma treatments and manganese oxide electrodeposition improve the specific capacitance of the CNTs. Nanocomposites of CNTs/MnO2 show high specific capacitance values of up to 750 Fg(-1). In addition, gas-surface interactions between functionalized and non-functionalized nanotubes, and volatile organic compounds, clearly show enhanced adsorption properties of the surface-modified nanotubes.