Electrochemical behaviors and hydration properties of multi-wall carbon nanotube coated electrodes in water

Vertically aligned and randomly oriented multi-wall carbon nanotube coated silicon substrates were used as electrochemical electrodes. The effects of anodization processes and cathodic treatments in deionized water on carbon nanotubes were studied by means of DC experiments as well as cyclic voltammetric (CV) measurements. Anodization processes modified as-grown and hydrophobic carbon nanotubes and converted them to become hydrophilic. Cathodic processes caused etching of carbon nanotubes. The etching products made originally clear water change into black water. The black etching products left on top of carbon nanotubes after water vaporized made the carbon nanotube coated electrode less hydrophobic than that of as-grown carbon nanotubes but also less hydrophilic than that of anodized carbon nanotubes.