Brief characterization of the PC electrode is shown in Figure . Scanning electron microscopy (SEM) images of the thin layer (~20 μm) of the PC reveal a lumpy surface that is formed on the graphite substrate (Image 1,2). In the expanded cross-section image, thin and flat PC mounted onto the rough polycrystalline graphite substrate is clearly visible (Image 4). Qualitatively, the appearance of a smooth, reactive surface is similar to that of RVC (Image 3), which is non-porous at microscopic scale (RVC appears to be a porous material at a macroscopic scale, however, the reactive carbon surface is non-porous). To further understand the behaviour of PC under electrochemical conditions, a simple potential sweep was applied (Figure ). The PC electrode showed a dramatically reduced capacitive current compared to a graphite electrode. Indeed, the cyclic voltammetry (CV) response is similar to that of RVC, supporting the hypothesis that this electrode material behaves as an amorphous carbon-type electrode. Thus, the CVD process used to make the PC electrode essentially closes the micropores of graphite to generate a material that exhibits RVClike reactivity.