Effects of Microfabrication Processing on the Electrochemistry of Carbon Nanofiber Electrodes

We describe the fabrication and electrochemical characterization of as-grown and postprocessed vertically aligned carbon nanofiber forest electrodes at macroscopic (5 mm) and microscopic dimensions (250 μm). We examine the impact of a variety of microfabrication processes that are typically employed during nanofiber-based device synthesis including refractory metal reactive ion etch, oxide coating and removal, and several oxygen-based etch processes all of which dramatically impact microscale electrode response. We also demonstrate that the high electrochemically active surface area of larger scale, macroscopic nanofiber forest electrodes can provide a buffering capacity against surface activation/inactivation. Under diffusion-limited transport conditions, this may preserve the electrochemical response of the electrode during storage and against the impacts of processing techniques used during nanofiber-based device fabrication.